WorldWideScience

Sample records for net electrical efficiency

  1. Net metering: zero electricity bill

    International Nuclear Information System (INIS)

    Mangi, A.; Khan, Z.

    2011-01-01

    Worldwide move towards renewable energy sources, environmental concerns and decentralization of the power sector have made net metering an attractive option for power generation at small scale. This paper discusses the net metering, economical issues of renewable sources in Pakistan, technical aspects, installation suitability according to varying terrain, existing utility rules and formulation of legislation for net metering making it economically attractive. (author)

  2. Demonstration tokamak fusion power plant for early realization of net electric power generation

    International Nuclear Information System (INIS)

    Hiwatari, R.; Okano, K.; Asaoka, Y.; Shinya, K.; Ogawa, Y.

    2005-01-01

    A demonstration tokamak fusion power plant Demo-CREST is proposed as the device for early realization of net electric power generation by fusion energy. The plasma configuration for Demo-CREST is optimized to satisfy the electric breakeven condition (the condition for net electric power, P e net = 0 MW) with the plasma performance of the ITER reference operation mode. This optimization method is considered to be suitable for the design of a demonstration power plant for early realization of net electric power generation, because the demonstration power plant has to ensure the net electric generation. Plasma performance should also be more reliably achieved than in past design studies. For the plasma performance planned in the present ITER programme, net electric power from 0 to 500 MW is possible with Demo-CREST under the following engineering conditions: maximum magnetic field 16 T, thermal efficiency 30%, NBI system efficiency 50% and NBI current drive power restricted to 200 MW. By replacing the blanket system with one of higher thermal efficiency, a net electric power of about 1000 MW is also possible so that the performance of the commercial plant with Demo-CREST can also be studied from the economic point of view. The development path from the experimental reactor 'ITER' to the commercial plant 'CREST' through the demonstration power plant 'Demo-CREST' is proposed as an example of the fast track concept. (author)

  3. Energy management for vehicle power net with flexible electric load demand

    NARCIS (Netherlands)

    Kessels, J.T.B.A.; Bosch, van den P.P.J.; Koot, M.W.T.; Jager, de A.G.

    2005-01-01

    The electric power demand in road vehicles increases rapidly and to supply all electric loads efficiently, energy management (EM) turns out to be a necessity. In general, EM exploits the storage capacity of a buffer connected to the vehicle's power net, such that energy is stored or retrieved at

  4. Generation of net electric power with a tokamak reactor under foreseeable physical and engineering conditions

    International Nuclear Information System (INIS)

    Hiwatari, R.; Asaoka, Y.; Okano, K.; Yoshida, T.; Tomabechi, K.

    2004-01-01

    This study reveals for the first time the plasma performance required for a tokamak reactor to generate net electric power under foreseeable engineering conditions. It was found that the reference plasma performance of the ITER inductive operation mode with β N = 1.8, HH = 1.0, andf nGW 0.85 had sufficient potential to achieve the electric break-even condition (net electric power P e net = 0MW) under the following engineering conditions: machine major radius 6.5m ≤ R p ≤ 8.5m, the maximum magnetic field on TF coils B tmax = 16 T, thermal efficiency η e 30%, and NBI system efficiency η NBI = 50%. The key parameters used in demonstrating net electric power generation in tokamak reactors are β N and fη GW . ≥ 3.0 is required for P e net ∼ 600MW with fusion power P f ∼ 3000MW. On the other hand, fη GW ≥ 1.0 is inevitable to demonstrate net electric power generation, if high temperatures, such as average temperatures of T ave > 16 keV, cannot be selected for the reactor design. To apply these results to the design of a tokamak reactor for demonstrating net electric power generation, the plasma performance diagrams on the Q vs P f (energy multiplication factor vs fusion power) space for several major radii (i.e. 6.5, 7.5, and 8.5 m) were depicted. From these figures, we see that a design with a major radius R p ∼ 7.5m seems preferable for demonstrating net electric power generation when one aims at early realization of fusion energy. (author)

  5. Net energy analysis of different electricity generation systems

    International Nuclear Information System (INIS)

    1994-07-01

    This document is a report on the net energy analysis of nuclear power and other electricity generation systems. The main objectives of this document are: To provide a comprehensive review of the state of knowledge on net energy analysis of nuclear and other energy systems for electricity generation; to address traditional questions such as whether nuclear power is a net energy producer or not. In addition, the work in progress on a renewed application of the net energy analysis method to environmental issues is also discussed. It is expected that this work could contribute to the overall comparative assessment of different energy systems which is an ongoing activity at the IAEA. 167 refs, 9 figs, 5 tabs

  6. Efficiency trends in electric machines and drives

    International Nuclear Information System (INIS)

    Mecrow, B.C.; Jack, A.G.

    2008-01-01

    Almost all electricity in the UK is generated by rotating electrical generators, and approximately half of it is used to drive electrical motors. This means that efficiency improvements to electrical machines can have a very large impact on energy consumption. The key challenges to increased efficiency in systems driven by electrical machines lie in three areas: to extend the application of variable-speed electric drives into new areas through reduction of power electronic and control costs; to integrate the drive and the driven load to maximise system efficiency; and to increase the efficiency of the electrical drive itself. In the short to medium term, efficiency gains within electrical machines will result from the development of new materials and construction techniques. Approximately a quarter of new electrical machines are driven by variable-speed drives. These are a less mature product than electrical machines and should see larger efficiency gains over the next 50 years. Advances will occur, with new types of power electronic devices that reduce switching and conduction loss. With variable-speed drives, there is complete freedom to vary the speed of the driven load. Replacing fixed-speed machines with variable-speed drives for a high proportion of industrial loads could mean a 15-30% energy saving. This could save the UK 15 billion kWh of electricity per year which, when combined with motor and drive efficiency gains, would amount to a total annual saving of 24 billion kWh

  7. Evaluation of the influence of electric nets on the behaviour of oviposition site seeking Anopheles gambiae s.s

    Science.gov (United States)

    2014-01-01

    Background Electric nets (e-nets) are used to analyse the flight behaviour of insects and have been used extensively to study the host-oriented flight of tsetse flies. Recently we adapted this tool to analyse the oviposition behaviour of gravid malaria vectors, Anopheles gambiae s.s., orienting towards aquatic habitats and traps by surrounding an artificial pond with e-nets and collecting electrocuted mosquitoes on sticky boards on the ground next to the nets. Here we study whether e-nets themselves affect the responses of gravid An. gambiae s.s.. Methods Dual-choice experiments were carried out in 80 m2 screened semi-field systems where 200 gravid An. gambiae s.s. were released each night for 12 nights per experiment. The numbers of mosquito landing on or approaching an oviposition site were studied by adding detergent to the water in an artificial pond or surrounding the pond with a square of e-nets. We also assessed whether the supporting framework of the nets or the sticky boards used to retain electrocuted mosquitoes influenced the catch. Results Two similar detergent treated ponds presented in choice tests caught an equal proportion of the mosquitoes released, whereas a pond surrounded by e-nets caught a higher proportion than an open pond (odds ratio (OR) 1.7, 95% confidence interval (CI) 1.1 - 2.7; p electric nets and the yellow boards on the approach of gravid females towards a pond suggests that the tower-like construction of the square of electric nets did not restrict the approach of females but the yellow sticky boards on the ground attract gravid females to a source of water (OR 2.7 95% CI 1.7 – 4.3; p trapping efficiency of the electric nets is increased when large yellow sticky boards are placed on the ground next to the e-nets to collect electrocuted mosquitoes, possibly because of increased visual contrast to the aquatic habitat. It is therefore important when comparing two treatments that the same trapping device is used in both. The

  8. Net metering study of switching effects on electromechanical meters[Report prepared for the Measurement Canada Electricity Net Metering Project

    Energy Technology Data Exchange (ETDEWEB)

    Van Overberghe, L. [Measurement Canada, London, ON (Canada)

    2006-03-03

    The feasibility of introducing net metering in the electricity sector was evaluated with particular reference to a project administered by Measurement Canada and Electro-Federation Canada (MicroPower Connect) in collaboration with Natural Resources Canada. The objective of the Measurement Canada Electricity Net Metering Project is to identify and eliminate the barriers introduced by the Electricity and Gas Inspection Act regarding the introduction of net metering. The purpose was to design a device that would allow rotation reversal in a residential electromechanical single phase meter. The device should approximate any fluctuations found in a typical net metering system. A series of tests were conducted to understand the influences, on errors, of forward-to-reverse and reverse-to-forward transitions, specifically to find evidence of error migration and mechanical stress. The project was designed to find and measure the effects of forward reverse switching on an electromechanical meter resulting from a change in energy flow. Twenty metres were calibrated in the forward direction in series from light load to high load. Power factor was not adjustable. Test points were then applied in both the forward and reverse directions. The exercise yielded individual errors which were aggregated to show average found errors after 3,000 transitions. Small shifts in errors were apparent and there was no evidence to support a disk flutter theory. refs., tabs., figs.

  9. Electrical efficiency losses occurred by the air compressor for PEMFC

    International Nuclear Information System (INIS)

    Haubrock, J.; Heideck, G.; Styczynski, Z.

    2006-01-01

    Fuel Cells are characterised by a high efficiency and comparatively small emissions. Depending on their partial load behaviour and their high efficiency, Fuel Cells are well suited for net connected or isolated autonomous energy generators for thermal and electricity power production. Proton Exchange Membrane (PEM) Fuel Cell systems need several external components to produce electricity and thermal power. However, the high theoretical degree of efficiency of 83% is decreased by these components. To reach higher fuel utilisation it is necessary to reduce the energy consumption of these components. In this study, the influence of the air supply compressor on the fuel utilisation is investigated and an optimization strategy was developed. The results were reviewed by a real test set up using an autonomous PEM Fuel Cell system. (authors)

  10. Assessing the efficiency of US electricity markets

    International Nuclear Information System (INIS)

    Arciniegas, I.; Barrett, C.; Marathe, A.

    2003-01-01

    The recent California's energy crisis has raised doubts about the benefits of energy deregulation. While it is true that the California electricity market is in turmoil, other electricity markets like the Pennsylvania-NewJersey-Maryland (PJM) are doing fine. This paper assesses the mark of efficiency reached by the electricity markets in California, New York, and PJM. It also compares the degree of efficiency across markets (forward vs. real time) and across time. No significant differences between the California and PJM electricity markets were discovered in the year of California's energy crisis (2000) using the co-integration tests. This research suggests that differences in price behavior between these two markets during 2000 did not arise from differences in efficiency. According to our analysis and measures of efficiency, PJM and California electricity markets are more efficient than the New York market. Also, as these markets become more mature over time, their efficiency level goes up. We also found evidence that a multi-settlement scheduling system leads to higher efficiency. (author)

  11. Electrical energy efficiency technologies and applications

    CERN Document Server

    Sumper, Andreas

    2012-01-01

    The improvement of electrical energy efficiency is fast becoming one of the most essential areas of sustainability development, backed by political initiatives to control and reduce energy demand. Now a major topic in industry and the electrical engineering research community, engineers have started to focus on analysis, diagnosis and possible solutions. Owing to the complexity and cross-disciplinary nature of electrical energy efficiency issues, the optimal solution is often multi-faceted with a critical solutions evaluation component to ensure cost effectiveness. This single-source refer

  12. Energy efficiency of electrical infrared heating elements

    International Nuclear Information System (INIS)

    Brown, K.J.; Farrelly, R.; O’Shaughnessy, S.M.; Robinson, A.J.

    2016-01-01

    Highlights: • Characterization of the radiant energy efficiency of infrared heating elements. • Performed for a commercially available ceramic heater element for two cases. • Total radiant power and net radiant efficiency is computed. • Radiant efficiencies are strongly dependant on the input power to the element. • In-plane efficiencies depend on the distance from the heater. - Abstract: A measurement system has been designed to characterize the radiant energy efficiency of infrared heating elements. The system also allows for measurement of the radiant heat flux distribution emitted from radiant heater assemblies. To facilitate these, a 6-axis robotic arm is fitted with a Schmidt–Boelter radiant heat flux gauge. A LabVIEW interface operates the robot and positions the sensor in the desired location and subsequently acquires the desired radiant heat flux measurement. To illustrate the functionality of the measurement system and methodology, radiant heat flux distributions and efficiency calculations are performed for a commercially available ceramic heater element for two cases. In the first, a spherical surface is traced around the entire heater assembly and the total radiant power and net radiant efficiency is computed. In the second, 50 cm × 50 cm vertical planes are traced parallel to the front face of the heater assembly at distances between 10 cm and 50 cm and the in-plane power and efficiencies are computed. The results indicate that the radiant efficiencies are strongly dependant on the input power to the element and, for the in-plane efficiencies, depend on the distance from the heater.

  13. Electric power transmission pricing regulations and efficiency

    International Nuclear Information System (INIS)

    Goldoni, G.

    1999-01-01

    An efficient-price mechanism for electricity transmission is very hard to find, essentially because of the natural monopoly condition of the grid and its peculiar interactions with generation. The use of Optimal Power Flow Models is difficult to implement and could be easily distorted by strategical behaviour of generators. These models, however, could became a valuable efficiency-test for actual transmission charges and codes [it

  14. Hall devices improve electric motor efficiency

    Science.gov (United States)

    Haeussermann, W.

    1979-01-01

    Efficiency of electric motors and generators is reduced by radial magnetic forces created by symmetric fields within device. Forces are sensed and counteracted by Hall devices on excitation or control windings. Hall generators directly measure and provide compensating control of anu asymmetry, eliminating additional measurements needed for calibration feedback control loop.

  15. A study on electric bicycle energy efficiency

    Directory of Open Access Journals (Sweden)

    Ivan EVTIMOV

    2015-09-01

    Full Text Available The paper presents a construction of an experimental electric bicycle for evaluation of the energy efficiency. The bicycle is equipped with onboard computer which can store the information about motion and energy consumption. The result concerning power, energy consumption, recharging during brake process, etc. are given. Energy consumption for 3 typical city routes is studied.

  16. Industry agreement on efficient electrical motors

    International Nuclear Information System (INIS)

    Schnyder, G.

    2004-01-01

    This comprehensive final report presents the results of a project carried out on behalf of the Swiss Federal Office of Energy (SFOE) and the Swiss Automation Pool (SAP) concerning the efficiency of electrical drives. The main goal of the project was to conclude a target agreement between the federal government and the Swiss electric motors/drives industry. This involves the promotion of the highest, 'eff1' energy-efficiency category of the three categories defined by the European Committee of Manufacturers of Electrical Machines and Power Electronics (CEMP). The report presents the findings of the project and recommends the banning of the use of motors in the lowest, 'eff3' category. Comparisons are made between the CEMP standards and further standards and promotion programmes in the USA and in Great Britain. Associated measures to be taken to aid the promotion of the drive standard are discussed

  17. Spreading The Net: The Multiple Benefits Of Energy Efficiency Improvements

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Improving energy efficiency can deliver a range of benefits to the economy and society. However energy efficiency programmes are often evaluated only on the basis of the energy savings they deliver. As a result, the full value of energy efficiency improvements in both national and global economies may be significantly underestimated. This also means that energy efficiency policy may not be optimised to target the potential of the full range of outcomes possible. Moreover, when the merit of energy efficiency programmes is judged solely on reductions in energy demand, programmes are susceptible to criticisms related to the rebound effect when the energy savings are less than expected due to other welfare gains. There are several reasons why the full range of outcomes from energy efficiency policy is not generally evaluated. First, it is due to the non-market, somewhat intangible, nature of the socioeconomic benefits, which makes them difficult to quantify. Second, the effects due to energy efficiency alone can be complex to isolate and to determine causality. Third, evaluators and policy makers working in the energy efficiency sphere are usually energy professionals, working for an energy agency or ministry, with little experience of how energy efficiency might impact other non-energy sectors. The result is an under-appreciation – and related underinvestment – in energy efficiency, and as a consequence, missed opportunities and benefits. These foregone benefits represent the ‘opportunity cost’ of failing to adequately evaluate and prioritize energy efficiency investments. The objective of this report is to fully outline the array of different benefits from improved energy efficiency and investigate their implications for policy design. By better understanding the different benefits arising from energy efficiency it should be easier for policy makers to prioritise the most significant outcomes, in addition to energy savings, in optimising energy efficiency

  18. Electrical efficiency and droop in MQW LEDs

    Science.gov (United States)

    Malyutenko, V. K.

    2014-02-01

    It is believed that low power conversion efficiency in commercial MQW LEDs occurs as a result of efficiency droop, current-induced dynamic degradation of the internal quantum efficiency, injection efficiency, and extraction efficiency. Broadly speaking, all these "quenching" mechanisms could be referred to as the optical losses. The vast advances of high-power InGaN and AlGaInP MQW LEDs have been achieved by addressing these losses. In contrast to these studies, in this paper we consider an alternative approach to make high-power LEDs more efficient. We identify current-induced electrical efficiency degradation (EED) as a strong limiting factor of power conversion efficiency. We found that EED is caused by current crowding followed by an increase in current-induced series resistance of a device. By decreasing the current spreading length, EED also causes the optical efficiency to degrade and stands for an important aspect of LED performance. This paper gives scientists the opportunity to look for different attributes of EED.

  19. Barriers to electric energy efficiency in Ghana

    Science.gov (United States)

    Berko, Joseph Kofi, Jr.

    Development advocates argue that sustainable development strategies are the best means to permanently improve living standards in developing countries. Advocates' arguments are based on the technical, financial, and environmental advantages of sustainable development. However, they have not addressed the organizational and administrative decision-making issues which are key to successful implementation of sustainable development in developing countries. Using the Ghanaian electricity industry as a case study, this dissertation identifies and analyzes organizational structures, administrative mechanisms, and decision-maker viewpoints that critically affect the success of adoption and implementation of energy efficiency within a sustainable development framework. Utilizing semi-structured interviews in field research, decision-makers' perceptions of the pattern of the industry's development, causes of the electricity supply shortfall, and barriers to electricity-use efficiency were identified. Based on the initial findings, the study formulated a set of policy initiatives to establish support for energy use efficiency. In a second set of interviews, these policy suggestions were presented to some of the top decision-makers to elicit their reactions. According to the decision-makers, the electricity supply shortfall is due to rapid urbanization and increased industrial consumption as a result of the structural adjustment program, rural electrification, and the sudden release of suppressed loads. The study found a lack of initiative and collaboration among industry decision-makers, and a related divergence in decision-makers' concerns and viewpoints. Also, lacking are institutional support systems and knowledge of proven energy efficiency strategies and technologies. As a result, planning, and even the range of perceived solutions to choose from are supply-side oriented. The final chapter of the study presents implications of its findings and proposes that any

  20. Energy-efficient electric motors study

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-23

    The study identifies the industrial decision makers, investigated the information they needed to know, how they can best be reached, and the motivating factors for purchasing energy-efficient electric motors. A survey was conducted of purchasers of integral horsepower polyphase motors. The survey measured current knowledge of and awareness of energy-efficient motors, decision-making criteria, information sources, purchase and usage patterns, and related factors. The survey data were used for the electric motor market penetration analysis. Additionally, a telephone survey was made. The study also provides analyses of distribution channels, commercialization constraints, and the impacts of government programs and rising energy prices. A description of study findings, conclusions, and recommendations is presented. Sample questionnaires and copies of letters to respondents are presented in 3 appendices. Appendices D and E contain descriptions of the methods used. (MCW)

  1. Efficiency Test Method for Electric Vehicle Chargers

    DEFF Research Database (Denmark)

    Kieldsen, Andreas; Thingvad, Andreas; Martinenas, Sergejus

    2016-01-01

    This paper investigates different methods for measuring the charger efficiency of mass produced electric vehicles (EVs), in order to compare the different models. The consumers have low attention to the loss in the charger though the impact on the driving cost is high. It is not a high priority...... different vehicles. A unified method for testing the efficiency of the charger in EVs, without direct access to the component, is presented. The method is validated through extensive tests of the models Renault Zoe, Nissan LEAF and Peugeot iOn. The results show a loss between 15 % and 40 %, which is far...

  2. Increasing Efficiency by Maximizing Electrical Output

    Science.gov (United States)

    2016-08-01

    to electricity technology in a few limited areas, one being a geothermal flash plant at Naval Air Weapons Station China Lake. But, there are few...portable generators to reduce fuel needs. d) Bottom cycling on a geothermal flash plant like the one at Naval Air Weapons Station China Lake...generation c) Increasing the efficiency of portable generators to reduce fuel needs. d) Bottom cycling on a geothermal flash plant like the one at Naval

  3. Renewable and efficient electric power systems

    CERN Document Server

    Masters, Gilbert M

    2013-01-01

    A solid, quantitative, practical introduction to a wide range of renewable energy systems-in a completely updated, new edition The second edition of Renewable and Efficient Electric Power Systems provides a solid, quantitative, practical introduction to a wide range of renewable energy systems. For each topic, essential theoretical background is introduced, practical engineering considerations associated with designing systems and predicting their performance are provided, and methods for evaluating the economics of these systems are presented. While the book focuses on

  4. A review of net metering mechanism for electricity renewable energy sources

    Energy Technology Data Exchange (ETDEWEB)

    Poullikkas, Andreas; Kourtis, George; Hadjipaschalis, Ioannis [Electricity Authority of Cyprus, P.O. Box 24506, 1399 Nicosia (Cyprus)

    2013-07-01

    In this work, an overview of the net metering mechanism for renewable energy sources for power generation (RES-E) systems is carried out. In particular, the net metering concept is examined with its benefits and misconceptions. Furthermore, a survey of the current operational net metering schemes in different countries in the world, such as, in Europe, USA, Canada, Thailand and Australia, is carried out. The survey indicated that there are different net metering mechanisms depending on the particularities of each country (or state in the case of USA). Especially, in Europe, only five countries are using net metering in a very simple form, such as, any amount of energy produced by the eligible RES-E technology is compensated from the energy consumed by the RES-E producer, which results to either a less overall electricity bill or to an exception in payment energy taxes. In the USA and the USA territories, any customer’s net excess generation is credited to the customer’s next electricity bill for a 12-month billing cycle at various rates or via a combination between rates. The actual type of net excess generation (NEG) credit is decided by a number of set criteria, such as the type of RES-E technology, the RES-E capacity limit, the type of customer and the type of utility. Regarding any excess credit at the end of the 12-month billing cycle, this is either granted to the utilities, or carries over indefinitely to the customer’s next electricity bill, or is reconciled annually at any rate, or provides an option to the customer to choose between the last two options.

  5. Conceptual design of an electricity generating tritium breeding blanket sector for INTOR/NET

    International Nuclear Information System (INIS)

    Bond, A.

    1984-01-01

    A study is made of a fusion reactor power blanket and its associated equipment with the objective of producing a conceptual design for a blanket sector of INTOR, or one of its national variants (e.g. NET), from which electricity could be generated simultaneously with the breeding of tritium. (author)

  6. Energy balance of the global photovoltaic (PV) industry--is the PV industry a net electricity producer?

    Science.gov (United States)

    Dale, Michael; Benson, Sally M

    2013-04-02

    A combination of declining costs and policy measures motivated by greenhouse gas (GHG) emissions reduction and energy security have driven rapid growth in the global installed capacity of solar photovoltaics (PV). This paper develops a number of unique data sets, namely the following: calculation of distribution of global capacity factor for PV deployment; meta-analysis of energy consumption in PV system manufacture and deployment; and documentation of reduction in energetic costs of PV system production. These data are used as input into a new net energy analysis of the global PV industry, as opposed to device level analysis. In addition, the paper introduces a new concept: a model tracking energetic costs of manufacturing and installing PV systems, including balance of system (BOS) components. The model is used to forecast electrical energy requirements to scale up the PV industry and determine the electricity balance of the global PV industry to 2020. Results suggest that the industry was a net consumer of electricity as recently as 2010. However, there is a >50% that in 2012 the PV industry is a net electricity provider and will "pay back" the electrical energy required for its early growth before 2020. Further reducing energetic costs of PV deployment will enable more rapid growth of the PV industry. There is also great potential to increase the capacity factor of PV deployment. These conclusions have a number of implications for R&D and deployment, including the following: monitoring of the energy embodied within PV systems; designing more efficient and durable systems; and deploying PV systems in locations that will achieve high capacity factors.

  7. MobileFaceNets: Efficient CNNs for Accurate Real-time Face Verification on Mobile Devices

    OpenAIRE

    Chen, Sheng; Liu, Yang; Gao, Xiang; Han, Zhen

    2018-01-01

    In this paper, we proposed a class of extremely efficient CNN models, MobileFaceNets, which use less than 1 million parameters and are specifically tailored for high-accuracy real-time face verification on mobile and embedded devices. We first make a simple analysis on the weakness of common mobile networks for face verification. The weakness has been well overcome by our specifically designed MobileFaceNets. Under the same experimental conditions, our MobileFaceNets achieve significantly sup...

  8. Energy-efficient electric motors study

    Science.gov (United States)

    1981-03-01

    A survey conducted of purchasers of integral horsepower polyphase motors measured current knowledge of and awareness of energy efficient motors, decision making criteria, information sources, purchase and usage patterns, and related factors. The data obtained were used for the electric motor market penetration analysis. Additionally, a telephone survey was made. The study also provides analyses of distribution channels, commercialization constraints, and the impacts of government programs and rising energy prices. Study findings, conclusions, and recommendations are presented. Sample questionnaires and copies of letters to respondents are presented in appendices as well as descriptions of the methods used.

  9. An Efficient Translation of Timed-Arc Petri Nets to Networks of Timed Automata

    DEFF Research Database (Denmark)

    Byg, Joakim; Jørgensen, Kenneth Yrke; Srba, Jiri

    2009-01-01

    Bounded timed-arc Petri nets with read-arcs were recently proven equivalent to networks of timed automata, though the Petri net model cannot express urgent behaviour and the described mutual trans- lations are rather inefficient. We propose an extension of timed-arc Petri nets with invariants...... to enforce urgency and with transport arcs to generalise the read-arcs. We also describe a novel translation from the extended timed-arc Petri net model to networks of timed automata. The translation is implemented in the tool TAPAAL and it uses UPPAAL as the verification engine. Our experiments confirm...... the efficiency of the translation and in some cases the translated models verify significantly faster than the native UPPAAL models do....

  10. Increased light-use efficiency sustains net primary productivity of shaded coffee plants in agroforestry system.

    Science.gov (United States)

    Charbonnier, Fabien; Roupsard, Olivier; le Maire, Guerric; Guillemot, Joannès; Casanoves, Fernando; Lacointe, André; Vaast, Philippe; Allinne, Clémentine; Audebert, Louise; Cambou, Aurélie; Clément-Vidal, Anne; Defrenet, Elsa; Duursma, Remko A; Jarri, Laura; Jourdan, Christophe; Khac, Emmanuelle; Leandro, Patricia; Medlyn, Belinda E; Saint-André, Laurent; Thaler, Philippe; Van Den Meersche, Karel; Barquero Aguilar, Alejandra; Lehner, Peter; Dreyer, Erwin

    2017-08-01

    In agroforestry systems, shade trees strongly affect the physiology of the undergrown crop. However, a major paradigm is that the reduction in absorbed photosynthetically active radiation is, to a certain extent, compensated by an increase in light-use efficiency, thereby reducing the difference in net primary productivity between shaded and non-shaded plants. Due to the large spatial heterogeneity in agroforestry systems and the lack of appropriate tools, the combined effects of such variables have seldom been analysed, even though they may help understand physiological processes underlying yield dynamics. In this study, we monitored net primary productivity, during two years, on scales ranging from individual coffee plants to the entire plot. Absorbed radiation was mapped with a 3D model (MAESPA). Light-use efficiency and net assimilation rate were derived for each coffee plant individually. We found that although irradiance was reduced by 60% below crowns of shade trees, coffee light-use efficiency increased by 50%, leaving net primary productivity fairly stable across all shade levels. Variability of aboveground net primary productivity of coffee plants was caused primarily by the age of the plants and by intraspecific competition among them (drivers usually overlooked in the agroforestry literature) rather than by the presence of shade trees. © 2017 John Wiley & Sons Ltd.

  11. Convergent evolution towards high net carbon gain efficiency contributes to the shade tolerance of palms (Arecaceae)

    NARCIS (Netherlands)

    Ma, Ren Yi; Zhang, Jiao Lin; Cavaleri, Molly A.; Sterck, Frank; Strijk, J.S.; Cao, Kun Fang

    2015-01-01

    Most palm species occur in the shaded lower strata of tropical rain forests, but how their traits relate to shade adaptation is poorly understood. We hypothesized that palms are adapted to the shade of their native habitats by convergent evolution towards high net carbon gain efficiency (CGEn),

  12. Blending of electricity pricing with time flavour - an analysis of net system benefit to an electric utility in India

    International Nuclear Information System (INIS)

    Bhardwaj, J.L.

    1992-01-01

    Demand-side Management is a powerful strategy for modifying electric energy consumption patterns for the mutual benefit of consumers, the supplier and the economy as a whole Time-of-use pricing of electricity suggest a policy where the price is time-differentiated so as to reduce contribution to the system-peak which determines the capacity and investments of a power-system. This paper describes a case-study of net system benefit to an electric utility in India by offering time-of-use tariff to high voltage (HV) industrial consumers. The study shows that there is a potential of shifting about 19% H.V. Industrial loads from peak to off-peak hours thereby benefitting both, the consumers and the utility. 1 fig., 2 tabs

  13. Correcting Detector Efficiency Effects in Event-by-Event Net-Proton Fluctuations

    CERN Document Server

    Peters, Michael

    2016-01-01

    Measurements of fluctuations of conserved quantities give valuable information on the susceptibilities of the nuclear matter produced in a heavy-ion collision, and could in principle be used to distinguish QGP from hadronic matter. However, measurements of the cumulants of conserved-quantity distributions are affected by the detector efficiency, which must be accounted for in order to ensure accuracy. Following the development of a toy model that simulates detector efficiency effects on net-proton number, various correction methods, including those developed by A. Bzdak and V. Koch, were implemented and tested in a wide range of conditions. We find that the first four cumulants of net-proton-number distribution can be accurately reproduced by the Koch-Bzdak corrections with reasonable input statistics. Various methods of correcting for $p_T$ dependence of detector efficiency are also explored.

  14. Perceptions on the effect of small electric fans on comfort inside bed nets in southern Ghana: a qualitative study.

    Science.gov (United States)

    Jaeger, Mulako S; Briët, Olivier J T; Keating, Joseph; Ahorlu, Collins K; Yukich, Joshua O; Oppong, Samuel; Nardini, Peter; Pfeiffer, Constanze

    2016-12-01

    Long-lasting insecticidal nets (LLINs) are known to be highly effective in reducing malaria transmission, morbidity and mortality. However, among those owning an LLIN, use rates are often suboptimal. A reported barrier to bed net use is discomfort due to heat. This qualitative study was part of a larger evaluation conducted in communities without electricity in rural Ghana to assess whether 0.8 W solar powered net fans can increase net use. Twenty-three key informant interviews with household heads in the study communities in Shai-Osudoku District, southern Ghana, were conducted from July to August 2015. The purpose of the interviews was to obtain insight into perceptions of participants about the net fan system in relation to LLIN use. While all study participants reported using LLINs, with mosquito nuisance prevention as the prime motivation, heat was also mentioned as a key barrier to net use. Respondents appreciated the net fans because they improved comfort inside bed nets. The LED light on the fan stand became the main source of light at night and positively influenced the perception of the intervention as a whole. The general acceptance of the net fan system by the study participants highlights the potential of the intervention to improve comfort inside mosquito nets. This, therefore, has a potential to increase bed net use in areas with low access to electricity.

  15. The Influence of Output Variability from Renewable Electricity Generation on Net Energy Calculations

    Directory of Open Access Journals (Sweden)

    Hannes Kunz

    2014-01-01

    Full Text Available One key approach to analyzing the feasibility of energy extraction and generation technologies is to understand the net energy they contribute to society. These analyses most commonly focus on a simple comparison of a source’s expected energy outputs to the required energy inputs, measured in the form of energy return on investment (EROI. What is not typically factored into net energy analysis is the influence of output variability. This omission ignores a key attribute of biological organisms and societies alike: the preference for stable returns with low dispersion versus equivalent returns that are intermittent or variable. This biologic predilection for stability, observed and refined in academic financial literature, has a direct relationship to many new energy technologies whose outputs are much more variable than traditional energy sources. We investigate the impact of variability on net energy metrics and develop a theoretical framework to evaluate energy systems based on existing financial and biological risk models. We then illustrate the impact of variability on nominal energy return using representative technologies in electricity generation, with a more detailed analysis on wind power, where intermittence and stochastic availability of hard-to-store electricity will be factored into theoretical returns.

  16. Reliability evaluation of the power supply of an electrical power net for safety-relevant applications

    International Nuclear Information System (INIS)

    Dominguez-Garcia, Alejandro D.; Kassakian, John G.; Schindall, Joel E.

    2006-01-01

    In this paper, we introduce a methodology for the dependability analysis of new automotive safety-relevant systems. With the introduction of safety-relevant electronic systems in cars, it is necessary to carry out a thorough dependability analysis of those systems to fully understand and quantify the failure mechanisms in order to improve the design. Several system level FMEAs are used to identify the different failure modes of the system and, a Markov model is constructed to quantify their probability of occurrence. A new power net architecture with application to new safety-relevant automotive systems, such as Steer-by-Wire or Brake-by-Wire, is used as a case study. For these safety-relevant loads, loss of electric power supply means loss of control of the vehicle. It is, therefore, necessary and critical to develop a highly dependable power net to ensure power to these loads under all circumstances

  17. Electric nets and sticky materials for analysing oviposition behaviour of gravid malaria vectors

    Directory of Open Access Journals (Sweden)

    Dugassa Sisay

    2012-11-01

    Full Text Available Abstract Background Little is known about how malaria mosquitoes locate oviposition sites in nature. Such knowledge is important to help devise monitoring and control measures that could be used to target gravid females. This study set out to develop a suite of tools that can be used to study the attraction of gravid Anopheles gambiae s.s. towards visual or olfactory cues associated with aquatic habitats. Methods Firstly, the study developed and assessed methods for using electrocuting nets to analyse the orientation of gravid females towards an aquatic habitat. Electric nets (1m high × 0.5m wide were powered by a 12V battery via a spark box. High and low energy settings were compared for mosquito electrocution and a collection device developed to retain electrocuted mosquitoes when falling to the ground. Secondly, a range of sticky materials and a detergent were tested to quantify if and where gravid females land to lay their eggs, by treating the edge of the ponds and the water surface. A randomized complete block design was used for all experiments with 200 mosquitoes released each day. Experiments were conducted in screened semi-field systems using insectary-reared An. gambiae s.s. Data were analysed by generalized estimating equations. Results An electric net operated at the highest spark box energy of a 400 volt direct current made the net spark, creating a crackling sound, a burst of light and a burning smell. This setting caught 64% less mosquitoes than a net powered by reduced voltage output that could neither be heard nor seen (odds ratio (OR 0.46; 95% confidence interval (CI 0.40-0.53, p Conclusion A square of four e-nets with yellow sticky boards as a collection device can be used for quantifying the numbers of mosquitoes approaching a small oviposition site. Shiny sticky surfaces attract gravid females possibly because they are visually mistaken as aquatic habitats. These materials might be developed further as gravid traps

  18. Energy efficiency indicators for high electric-load buildings

    Energy Technology Data Exchange (ETDEWEB)

    Aebischer, Bernard; Balmer, Markus A.; Kinney, Satkartar; Le Strat, Pascale; Shibata, Yoshiaki; Varone, Frederic

    2003-06-01

    Energy per unit of floor area is not an adequate indicator for energy efficiency in high electric-load buildings. For two activities, restaurants and computer centres, alternative indicators for energy efficiency are discussed.

  19. maximum conversion efficiency of thermionic heat to electricity

    African Journals Online (AJOL)

    DJFLEX

    Dushman constant ... Several attempts on the direct conversion of heat to electricity ... The net current density in the system is equal to jE – jC , which gets over the potential barrier. jE and jC are given by the Richardson-. Dushman equation as. │. ⌋.

  20. Caught in a net: Retention efficiency of microplankton ≥ 10 and < 50 μm collected on mesh netting

    Science.gov (United States)

    Molina, Vanessa; Robbins-Wamsley, Stephanie H.; Riley, Scott C.; First, Matthew R.; Drake, Lisa A.

    2018-03-01

    Living organisms ≥ 10 μm and loss of organisms that, in turn, may underestimate the concentration of organisms within samples. To address this loss, the retention efficiency (RE) was determined for six filtration approaches using laboratory cultures of microalgae and ambient marine organisms. The approaches employed a membrane filter or mesh nettings of different compositions (nylon, stainless steel, polyester, and polycarbonate), nominal pore sizes (5, 7, and 10 μm), and filtering sequences (e.g., pre-filtering water through a coarse filter). Additionally, in trials with polycarbonate track etched (PCTE) membrane filters, water was amended with particulate material to increase turbidity. Organisms ≥ 10 μm were counted in the material retained on the filter (the filtrand), the material passing through the filter (the filtrate), and the whole water (i.e., unfiltered water). In addition, variable fluorescence fluorometry was used to gauge the relative photochemical yield of phytoplankton-a proximal measurement of the physiological status of phytoplankton-in the size fractions. Further, the mesh types and filters were examined using scanning electron microscopy, which showed irregular openings. The RE of cultured organisms-calculated as the concentration in the filtrand relative to combined concentration in the filtrand and the filtrate-was high for all filtration approaches when laboratory cultures were assessed (> 93%), but RE ranged from 66 to 98% when mixed assemblages of ambient organisms were evaluated. Although PCTE membrane filters had the highest RE (98%), it was not significantly higher than the efficiencies of the 7-μm polyester, Double 7-μm polyester, and Dual 35-μm and 7-μm polyester approaches, but it was significantly higher than the 5-μm nylon and 5-μm stainless steel techniques. This result suggests that PCTE membrane filters perform comparably to 7-μm polyester meshes, so that any of these approaches could be used for concentrating

  1. VP-Nets : Efficient automatic localization of key brain structures in 3D fetal neurosonography.

    Science.gov (United States)

    Huang, Ruobing; Xie, Weidi; Alison Noble, J

    2018-04-23

    Three-dimensional (3D) fetal neurosonography is used clinically to detect cerebral abnormalities and to assess growth in the developing brain. However, manual identification of key brain structures in 3D ultrasound images requires expertise to perform and even then is tedious. Inspired by how sonographers view and interact with volumes during real-time clinical scanning, we propose an efficient automatic method to simultaneously localize multiple brain structures in 3D fetal neurosonography. The proposed View-based Projection Networks (VP-Nets), uses three view-based Convolutional Neural Networks (CNNs), to simplify 3D localizations by directly predicting 2D projections of the key structures onto three anatomical views. While designed for efficient use of data and GPU memory, the proposed VP-Nets allows for full-resolution 3D prediction. We investigated parameters that influence the performance of VP-Nets, e.g. depth and number of feature channels. Moreover, we demonstrate that the model can pinpoint the structure in 3D space by visualizing the trained VP-Nets, despite only 2D supervision being provided for a single stream during training. For comparison, we implemented two other baseline solutions based on Random Forest and 3D U-Nets. In the reported experiments, VP-Nets consistently outperformed other methods on localization. To test the importance of loss function, two identical models are trained with binary corss-entropy and dice coefficient loss respectively. Our best VP-Net model achieved prediction center deviation: 1.8 ± 1.4 mm, size difference: 1.9 ± 1.5 mm, and 3D Intersection Over Union (IOU): 63.2 ± 14.7% when compared to the ground truth. To make the whole pipeline intervention free, we also implement a skull-stripping tool using 3D CNN, which achieves high segmentation accuracy. As a result, the proposed processing pipeline takes a raw ultrasound brain image as input, and output a skull-stripped image with five detected key brain

  2. Preliminary survey on electric energy efficiency in Ethiopia:- Areas of ...

    African Journals Online (AJOL)

    In this paper the significance of electric energy efficiency improvement and major areas of loss in Ethiopia's electric power system are highlighted for further rigorous study. Major electric energy loss areas in the utility transmission and distribution systems and consumer premises are indicated. In the consumer area the loss ...

  3. Developing Efficient Urban Electrical Systems Using Microgrids

    Energy Technology Data Exchange (ETDEWEB)

    Gahagan, Michael

    2010-09-15

    Electric vehicles and battery storage will complicate utility operations and strain existing networks. One possible solution is the implementation of 'microgrids' autonomous electricity environments that operate within a larger electric utility grid and their 'controllers' Microgrids direct locally generated power to local demand, coordinate with centralized utility networks to meet additional demand, and pass excess supply to neighboring microgrids. This paper explains the evolution of microgrids. It details their design and operation. It also reviews their many benefits within urban settings, including minimizing customer costs while maximizing use of local generation from clean, renewable resources.

  4. Effect of proton-conduction in electrolyte on electric efficiency of multi-stage solid oxide fuel cells

    Science.gov (United States)

    Matsuzaki, Yoshio; Tachikawa, Yuya; Somekawa, Takaaki; Hatae, Toru; Matsumoto, Hiroshige; Taniguchi, Shunsuke; Sasaki, Kazunari

    2015-07-01

    Solid oxide fuel cells (SOFCs) are promising electrochemical devices that enable the highest fuel-to-electricity conversion efficiencies under high operating temperatures. The concept of multi-stage electrochemical oxidation using SOFCs has been proposed and studied over the past several decades for further improving the electrical efficiency. However, the improvement is limited by fuel dilution downstream of the fuel flow. Therefore, evolved technologies are required to achieve considerably higher electrical efficiencies. Here we present an innovative concept for a critically-high fuel-to-electricity conversion efficiency of up to 85% based on the lower heating value (LHV), in which a high-temperature multi-stage electrochemical oxidation is combined with a proton-conducting solid electrolyte. Switching a solid electrolyte material from a conventional oxide-ion conducting material to a proton-conducting material under the high-temperature multi-stage electrochemical oxidation mechanism has proven to be highly advantageous for the electrical efficiency. The DC efficiency of 85% (LHV) corresponds to a net AC efficiency of approximately 76% (LHV), where the net AC efficiency refers to the transmission-end AC efficiency. This evolved concept will yield a considerably higher efficiency with a much smaller generation capacity than the state-of-the-art several tens-of-MW-class most advanced combined cycle (MACC).

  5. Net air emissions from electric vehicles: the effect of carbon price and charging strategies.

    Science.gov (United States)

    Peterson, Scott B; Whitacre, J F; Apt, Jay

    2011-03-01

    Plug-in hybrid electric vehicles (PHEVs) may become part of the transportation fleet on time scales of a decade or two. We calculate the electric grid load increase and emissions due to vehicle battery charging in PJM and NYISO with the current generation mix, the current mix with a $50/tonne CO(2) price, and this case but with existing coal generators retrofitted with 80% CO(2) capture. We also examine all new generation being natural gas or wind+gas. PHEV fleet percentages between 0.4 and 50% are examined. Vehicles with small (4 kWh) and large (16 kWh) batteries are modeled with driving patterns from the National Household Transportation Survey. Three charging strategies and three scenarios for future electric generation are considered. When compared to 2020 CAFE standards, net CO(2) emissions in New York are reduced by switching from gasoline to electricity; coal-heavy PJM shows somewhat smaller benefits unless coal units are fitted with CCS or replaced with lower CO(2) generation. NO(X) is reduced in both RTOs, but there is upward pressure on SO(2) emissions or allowance prices under a cap.

  6. Efficiency and deregulation of the electricity market in Singapore

    International Nuclear Information System (INIS)

    Youngho Chang; Tuan Hin Tay

    2006-01-01

    This study examines production efficiency of electricity generation in the New Electricity Market of Singapore (NEMS), where deregulation is currently proceeding. Singapore is reliant on foreign direct investments and exports so competition from countries with lower costs such as China and India is exerting pressure on the government to reduce the costs of doing business here. Electricity cost is one of these. Deregulation is believed to be able to bring about lower electricity costs due to the various efficiency gains possible. This study concerns itself mainly with production efficiency and attempts to calculate possible production efficiency gains by using linear programming model. Production-efficiency gains are quantified by the base case scenario of continued regulation versus four counterfactual deregulation scenarios. The results indicate that cost gains could be about eight per cent of current production cost, and this is possibly a lower-bound estimate. However, whether the purported efficiency gains are realized is to be seen as the deregulation proceeds. (author)

  7. Efficiency and deregulation of the electricity market in Singapore

    International Nuclear Information System (INIS)

    Chang, Youngho; Hin Tay, Tuan

    2006-01-01

    This study examines production efficiency of electricity generation in the New Electricity Market of Singapore (NEMS), where deregulation is currently proceeding. Singapore is reliant on foreign direct investments and exports so competition from countries with lower costs such as China and India is exerting pressure on the government to reduce the costs of doing business here. Electricity cost is one of these. Deregulation is believed to be able to bring about lower electricity costs due to the various efficiency gains possible. This study concerns itself mainly with production efficiency and attempts to calculate possible production efficiency gains by using linear programming model. Production-efficiency gains are quantified by the base case scenario of continued regulation versus four counterfactual deregulation scenarios. The results indicate that cost gains could be about eight per cent of current production cost, and this is possibly a lower-bound estimate. However, whether the purported efficiency gains are realized is to be seen as the deregulation proceeds

  8. Estimation of absorbed photosynthetically active radiation and vegetation net production efficiency using satellite data

    International Nuclear Information System (INIS)

    Hanan, N.P.; Prince, S.D.; Begue, A.

    1995-01-01

    The amount of photosynthetically active radiation (PAR) absorbed by green vegetation is an important determinant of photosynthesis and growth. Methods for the estimation of fractional absorption of PAR (iff PAR ) for areas greater than 1 km 2 using satellite data are discussed, and are applied to sites in the Sahel that have a sparse herb layer and tree cover of less than 5%. Using harvest measurements of seasonal net production, net production efficiencies are calculated. Variation in estimates of seasonal PAR absorption (APAR) caused by the atmospheric correction method and relationship between surface reflectances and iff PAR is considered. The use of maximum value composites of satellite NDVI to reduce the effect of the atmosphere is shown to produce inaccurate APAR estimates. In this data set, however, atmospheric correction using average optical depths was found to give good approximations of the fully corrected data. A simulation of canopy radiative transfer using the SAIL model was used to derive a relationship between canopy NDVI and iff PAR . Seasonal APAR estimates assuming a 1:1 relationship between iff PAR and NDVI overestimated the SAIL modeled results by up to 260%. The use of a modified 1:1 relationship, where iff PAR was assumed to be linearly related to NDVI scaled between minimum (soil) and maximum (infinite canopy) values, underestimated the SAIL modeled results by up to 35%. Estimated net production efficiencies (ϵ n , dry matter per unit APAR) fell in the range 0.12–1.61 g MJ −1 for above ground production, and in the range 0.16–1.88 g MJ −1 for total production. Sites with lower rainfall had reduced efficiencies, probably caused by physiological constraints on photosynthesis during dry conditions. (author)

  9. Evaluation of efficiency in Japan electric power companies

    International Nuclear Information System (INIS)

    Ghaderi, F.; Muyajima, M.

    2001-01-01

    Achieving energy efficiency also must consider supply efficiency, how much energy it takes to generate electricity and transmit it to the end user. system efficiency reflects the loss of energy during the processes of generation, transmission and distribution of electricity. Of the millions of tons of coal that are burned to produce heat in generation of electricity every year, only one third is converted into electricity.The electric power plant immediately uses 5 to 10 percent of that energy for use in the plant. Around another 10 percent of this energy is consumed in the transmission and distribution of electric energy to end users. Overall,more that 70 percent of the energy used to produce and deliver electricity never gets to the end user. The costs of this wasted energy are reflected in the customer's electricity bill. Furthermore, once delivered, users of electricity are subjected to more h idden c osts the demand charge which reflects the rate at which consumers draw energy from the power plant during a particular time of day, are also affected by the time of year. This additional charge c n be dramatic. For example, the cost for using electric air conditioning at the w rong t ime of the day , are also affected by the time of year. This additional charge can be dramatic. For example, the cost for using electric air conditioning at the wrong time of the day could be as much as 25 to 40 percent higher than what a facility normally pays for electricity during off-peak times. Minimizing the costs of operations, therefor, is a must for all electric companies. In the other hand utility rates, such as the cost of electricity, are a necessary element of operating in all enterprises.In some industries the payment over electricity make a large percentage of their total expenses, but that doesn't mean that every effort should not be made to reduce their impact on the bottom line, it should be considered that a very small change in operating procedure can change

  10. Differential electricity pricing and energy efficiency in South Africa

    International Nuclear Information System (INIS)

    Kohler, Marcel

    2014-01-01

    By international standards the economy of South Africa is extremely energy intensive with only a few countries having higher intensities. SA's primary energy use per unit of GDP is amongst the highest in the world. The high energy and electricity intensity of the economy partly reflects SA's resource endowments (in particular the abundance of coal) but is also a function of the historical under-pricing of coal and electricity by the authorities. South African mining and industrial electricity efficiency is particularly concerning and considerably lower than the global average. This paper sets out to fill a significant gap in the South African energy literature by highlighting the importance of incorporating electricity demand factors as part of the country's energy policy and electricity planning horizon. The paper focuses its attention on modelling the electricity consumption of SA's industrial and mining sectors given these account for the lion's share of electricity demand. A differential electricity pricing policy which targets electricity intensive industrial and mining activities (as practised in China since 2004) is viewed by the author to be a superior policy to blanket electricity price increases administered by authorities in an effort to encourage electricity savings and improve energy efficiency in South Africa. - Highlights: • SA's primary energy use per unit of GDP is amongst the highest in the world. • SA industrial electricity efficiency is considerably lower than the global average. • A differential electricity pricing policy which targets electricity intensive activities. • Differential tariffs raise the cost of energy inefficiency and induces energy saving. • Highlights importance of energy demand modelling in electricity supply planning

  11. Comparison of copepod collection efficiencies by three commonly used plankton nets: A case study in Bohai Sea, China

    Science.gov (United States)

    Chen, Hongju; Yu, Hao; Liu, Guangxing

    2016-12-01

    Selection of net with a suitable mesh size is a key concern in the quantitative assessment of zooplankton, which is crucial to understand pelagic ecosystem processes. This study compared the copepod collecting efficiency of three commonly used plankton nets, namely, the China standard coarse net (505 μm mesh), the China standard fine net (77 μm), and the WP-2 net (200 μm). The experiment was performed at six stations in the Bohai Sea during the autumn of 2012. The coarse net substantially under-sampled small individuals (body widths copepod species but failed to collect rare species. The WP-2 net appeared to be a compromise of the two other nets, collecting both small copepods and rare species. The abundance of copepods collected by the coarse net (126.4 ± 86.5 ind m-3) was one to two orders of magnitude lower than that by the WP-2 net (5802.4 ± 2595.4 ind m-3), and the value of the fine net (11117.0 ± 4563.41 ind m-3) was nearly twice that of the WP-2 net. The abundance of large copepods ( i.e., adult Calanus sinicus) in the three nets showed no significant differences, but the abundance of small copepods declined with decreasing mesh size. The difference in abundance resulted from the under-sampling of small copepods with body widths < 672 μm and < 266 μm by the coarse and WP-2 nets, respectively.

  12. Economic-efficiency considerations in restructuring electric markets

    Energy Technology Data Exchange (ETDEWEB)

    Hill, L.J.

    1996-12-01

    In response to the Energy Policy Act of 1992 and the Federal Energy Regulatory Commission`s subsequent rulemaking on transmission access, many states are exploring options to restructure their electric industries. In their deliberations on restructuring, policymakers should consider (1) the reliability of the electric system; (2) income-distribution effects on ratepayers and utilities; (3) social consequences such as effects on energy conservation, renewable energy, and the environment; and (4) economic efficiency. We address economic-efficiency considerations in this study. Economic efficiency is important because it is one of the primary reasons that policymakers should consider restructuring in the first place: improving the electric-industry`s efficiency lowers costs and, hence, electric prices. In this study, we look at the sources of (in)efficiency in existing and proposed electric markets with the objective of guiding policymakers to design efficient electric markets. The advantages of a competitive market are well known: it leads to lower costs for the utility, lower prices for consumers, more product choices, better customer service, and often the need for less regulation by federal and state agencies. In the short run, firms who cannot produce at the market-clearing price are forced to leave the industry, ensuring that customers have the lowest price possible. In the long run, competition promotes innovation and lower costs. The physical and institutional characteristics of the U.S. electric industry, however, could be impediments to attaining efficiently run, competitive markets. Because of these characteristics, there are multiple sources of efficiencies and inefficiencies in existing electric markets, and there will be multiple sources in restructured ones. The objective of policymakers should not be to trade one set of inefficiencies in existing electric markets for another set in restructured markets.

  13. Economic-efficiency considerations in restructuring electric markets

    International Nuclear Information System (INIS)

    Hill, L.J.

    1996-12-01

    In response to the Energy Policy Act of 1992 and the Federal Energy Regulatory Commission's subsequent rulemaking on transmission access, many states are exploring options to restructure their electric industries. In their deliberations on restructuring, policymakers should consider (1) the reliability of the electric system; (2) income-distribution effects on ratepayers and utilities; (3) social consequences such as effects on energy conservation, renewable energy, and the environment; and (4) economic efficiency. We address economic-efficiency considerations in this study. Economic efficiency is important because it is one of the primary reasons that policymakers should consider restructuring in the first place: improving the electric-industry's efficiency lowers costs and, hence, electric prices. In this study, we look at the sources of (in)efficiency in existing and proposed electric markets with the objective of guiding policymakers to design efficient electric markets. The advantages of a competitive market are well known: it leads to lower costs for the utility, lower prices for consumers, more product choices, better customer service, and often the need for less regulation by federal and state agencies. In the short run, firms who cannot produce at the market-clearing price are forced to leave the industry, ensuring that customers have the lowest price possible. In the long run, competition promotes innovation and lower costs. The physical and institutional characteristics of the U.S. electric industry, however, could be impediments to attaining efficiently run, competitive markets. Because of these characteristics, there are multiple sources of efficiencies and inefficiencies in existing electric markets, and there will be multiple sources in restructured ones. The objective of policymakers should not be to trade one set of inefficiencies in existing electric markets for another set in restructured markets

  14. Potential Benefits from Improved Energy Efficiency of KeyElectrical Products: The Case of India

    Energy Technology Data Exchange (ETDEWEB)

    McNeil, Michael; Iyer, Maithili; Meyers, Stephen; Letschert,Virginie; McMahon, James E.

    2005-12-20

    The goal of this project was to estimate the net benefits that cost-effective improvements in energy efficiency can bring to developing countries. The study focused on four major electrical products in the world's second largest developing country, India. These products--refrigerators, room air conditioners, electric motors, and distribution transformers--are important targets for efficiency improvement in India and in other developing countries. India is an interesting subject of study because of it's size and rapid economic growth. Implementation of efficient technologies in India would save billions in energy costs, and avoid hundreds of megatons of greenhouse gas emissions. India also serves as an example of the kinds of improvement opportunities that could be pursued in other developing countries.

  15. Measurement of net electric charge and dipole moment of dust aggregates in a complex plasma.

    Science.gov (United States)

    Yousefi, Razieh; Davis, Allen B; Carmona-Reyes, Jorge; Matthews, Lorin S; Hyde, Truell W

    2014-09-01

    Understanding the agglomeration of dust particles in complex plasmas requires knowledge of basic properties such as the net electrostatic charge and dipole moment of the dust. In this study, dust aggregates are formed from gold-coated mono-disperse spherical melamine-formaldehyde monomers in a radiofrequency (rf) argon discharge plasma. The behavior of observed dust aggregates is analyzed both by studying the particle trajectories and by employing computer models examining three-dimensional structures of aggregates and their interactions and rotations as induced by torques arising from their dipole moments. These allow the basic characteristics of the dust aggregates, such as the electrostatic charge and dipole moment, as well as the external electric field, to be determined. It is shown that the experimental results support the predicted values from computer models for aggregates in these environments.

  16. Estimating the net electricity energy generation and demand using the ant colony optimization approach. Case of Turkey

    International Nuclear Information System (INIS)

    Toksari, M. Duran

    2009-01-01

    This paper presents Turkey's net electricity energy generation and demand based on economic indicators. Forecasting model for electricity energy generation and demand is first proposed by the ant colony optimization (ACO) approach. It is multi-agent system in which the behavior of each ant is inspired by the foraging behavior of real ants to solve optimization problem. Ant colony optimization electricity energy estimation (ACOEEE) model is developed using population, gross domestic product (GDP), import and export. All equations proposed here are linear electricity energy generation and demand (linear A COEEGE and linear ACOEEDE) and quadratic energy generation and demand (quadratic A COEEGE and quadratic ACOEEDE). Quadratic models for both generation and demand provided better fit solution due to the fluctuations of the economic indicators. The ACOEEGE and ACOEEDE models indicate Turkey's net electricity energy generation and demand until 2025 according to three scenarios. (author)

  17. Changes in collection efficiency in nylon net filter media through magnetic alignment of elongated aerosol particles.

    Science.gov (United States)

    Lam, Christopher O; Finlay, W H

    2009-10-01

    Fiber aerosols tend to align parallel to surrounding fluid streamlines in shear flows, making their filtration more difficult. However, previous research indicates that composite particles made from cromoglycic acid fibers coated with small nanoscaled magnetite particles can align with an applied magnetic field. The present research explored the effect of magnetically aligning these fibers to increase their filtration. Nylon net filters were challenged with the aerosol fibers, and efficiency tests were performed with and without a magnetic field applied perpendicular to the flow direction. We investigated the effects of varying face velocities, the amount of magnetite material on the aerosol particles, and magnetic field strengths. Findings from the experiments, matched by supporting single-fiber theories, showed significant efficiency increases at the low face velocity of 1.5 cm s(-1) at all magnetite compositions, with efficiencies more than doubling due to magnetic field alignment in certain cases. At a higher face velocity of 5.12 cm s(-1), filtration efficiencies were less affected by the magnetic field alignment being, at most, 43% higher for magnetite weight compositions up to 30%, while at a face velocity of 10.23 cm s(-1) alignment effects were insignificant. In most cases, efficiencies became independent of magnetic field strength above 50 mT, suggesting full alignment of the fibers. The present data suggest that fiber alignment in a magnetic field may warrant applications in the filtration and detection of fibers, such as asbestos.

  18. Electricity: France tries to restore efficiency

    International Nuclear Information System (INIS)

    Chauveau, L.; Mulot, R.

    2012-01-01

    While recalling some data regarding the French energy consumption and its costs for the French households, the authors evoke Premio, the oldest experimental smart grid in Europe, and describe its operation. They comment the experience made in Brittany where households are warned when a consumption peak occurs, and will be equipped with devices which will automatically cut the electricity in this situation. They outline the role smart grids could have in energy savings. They also comment the possibilities of the Linky smart meter and the associated network security problems

  19. An approach to prospective consequential life cycle assessment and net energy analysis of distributed electricity generation

    International Nuclear Information System (INIS)

    Jones, Christopher; Gilbert, Paul; Raugei, Marco; Mander, Sarah; Leccisi, Enrica

    2017-01-01

    Increasing distributed renewable electricity generation is one of a number of technology pathways available to policy makers to meet environmental and other sustainability goals. Determining the efficacy of such a pathway for a national electricity system implies evaluating whole system change in future scenarios. Life cycle assessment (LCA) and net energy analysis (NEA) are two methodologies suitable for prospective and consequential analysis of energy performance and associated impacts. This paper discusses the benefits and limitations of prospective and consequential LCA and NEA analysis of distributed generation. It concludes that a combined LCA and NEA approach is a valuable tool for decision makers if a number of recommendations are addressed. Static and dynamic temporal allocation are both needed for a fair comparison of distributed renewables with thermal power stations to account for their different impact profiles over time. The trade-offs between comprehensiveness and uncertainty in consequential analysis should be acknowledged, with system boundary expansion and system simulation models limited to those clearly justified by the research goal. The results of this approach are explorative, rather than for accounting purposes; this interpretive remit, and the assumptions in scenarios and system models on which results are contingent, must be clear to end users. - Highlights: • A common LCA and NEA framework for prospective, consequential analysis is discussed. • Approach to combined LCA and NEA of distributed generation scenarios is proposed. • Static and dynamic temporal allocation needed to assess distributed generation uptake.

  20. Efficient Probabilistic Diagnostics for Electrical Power Systems

    Science.gov (United States)

    Mengshoel, Ole J.; Chavira, Mark; Cascio, Keith; Poll, Scott; Darwiche, Adnan; Uckun, Serdar

    2008-01-01

    We consider in this work the probabilistic approach to model-based diagnosis when applied to electrical power systems (EPSs). Our probabilistic approach is formally well-founded, as it based on Bayesian networks and arithmetic circuits. We investigate the diagnostic task known as fault isolation, and pay special attention to meeting two of the main challenges . model development and real-time reasoning . often associated with real-world application of model-based diagnosis technologies. To address the challenge of model development, we develop a systematic approach to representing electrical power systems as Bayesian networks, supported by an easy-to-use speci.cation language. To address the real-time reasoning challenge, we compile Bayesian networks into arithmetic circuits. Arithmetic circuit evaluation supports real-time diagnosis by being predictable and fast. In essence, we introduce a high-level EPS speci.cation language from which Bayesian networks that can diagnose multiple simultaneous failures are auto-generated, and we illustrate the feasibility of using arithmetic circuits, compiled from Bayesian networks, for real-time diagnosis on real-world EPSs of interest to NASA. The experimental system is a real-world EPS, namely the Advanced Diagnostic and Prognostic Testbed (ADAPT) located at the NASA Ames Research Center. In experiments with the ADAPT Bayesian network, which currently contains 503 discrete nodes and 579 edges, we .nd high diagnostic accuracy in scenarios where one to three faults, both in components and sensors, were inserted. The time taken to compute the most probable explanation using arithmetic circuits has a small mean of 0.2625 milliseconds and standard deviation of 0.2028 milliseconds. In experiments with data from ADAPT we also show that arithmetic circuit evaluation substantially outperforms joint tree propagation and variable elimination, two alternative algorithms for diagnosis using Bayesian network inference.

  1. Electricity End Uses, Energy Efficiency, and Distributed Energy Resources Baseline

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Lisa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wei, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Morrow, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Deason, Jeff [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Schiller, Steven R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Leventis, Greg [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Smith, Sarah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Leow, Woei Ling [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Levin, Todd [Argonne National Lab. (ANL), Argonne, IL (United States); Plotkin, Steven [Argonne National Lab. (ANL), Argonne, IL (United States); Zhou, Yan [Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)

    2017-01-01

    This report was developed by a team of analysts at Lawrence Berkeley National Laboratory, with Argonne National Laboratory contributing the transportation section, and is a DOE EPSA product and part of a series of “baseline” reports intended to inform the second installment of the Quadrennial Energy Review (QER 1.2). QER 1.2 provides a comprehensive review of the nation’s electricity system and cover the current state and key trends related to the electricity system, including generation, transmission, distribution, grid operations and planning, and end use. The baseline reports provide an overview of elements of the electricity system. This report focuses on end uses, electricity consumption, electric energy efficiency, distributed energy resources (DERs) (such as demand response, distributed generation, and distributed storage), and evaluation, measurement, and verification (EM&V) methods for energy efficiency and DERs.

  2. Exploring utility organization electricity generation, residential electricity consumption, and energy efficiency: A climatic approach

    International Nuclear Information System (INIS)

    Craig, Christopher A.; Feng, Song

    2017-01-01

    Highlights: • Study examined impact of electricity fuel sources and consumption on emissions. • 97.2% of variability in emissions explained by coal and residential electricity use. • Increasing cooling degree days significantly related to increased electricity use. • Effectiveness of state-level energy efficiency programs showed mixed results. - Abstract: This study examined the impact of electricity generation by fuel source type and electricity consumption on carbon emissions to assess the role of climatic variability and energy efficiency (EE) in the United States. Despite high levels of greenhouse gas emissions, residential electricity consumption continues to increase in the United States and fossil fuels are the primary fuel source of electricity generation. 97.2% of the variability in carbon emissions in the electricity industry was explained by electricity generation from coal and residential electricity consumption. The relationships between residential electricity consumption, short-term climatic variability, long-term climatic trends, short-term reduction in electricity from EE programs, and long-term trends in EE programs was examined. This is the first study of its nature to examine these relationships across the 48 contiguous United States. Inter-year and long-term trends in cooling degree days, or days above a baseline temperature, were the primary climatic drivers of residential electricity consumption. Cooling degree days increased across the majority of the United States during the study period, and shared a positive relationship with residential electricity consumption when findings were significant. The majority of electricity reduction from EE programs was negatively related to residential electricity consumption where findings were significant. However, the trend across the majority of states was a decrease in electricity reduction from EE while residential electricity consumption increased. States that successfully reduced consumption

  3. Electric motor systems in developing countries: Opportunities for efficiency improvement

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, S.; Monahan, P.; Lewis, P.; Greenberg, S. [Lawrence Berkeley Lab., CA (United States); Nadel, S. [American Council for an Energy-Efficient Economy, Washington, DC (United States)

    1993-08-01

    This report presents an overview of the current status and efficiency improvement potential of industrial motor systems in developing countries. Better management of electric motor systems is of particular relevance in developing countries, where improved efficiency can lead to increased productivity and slower growth in electricity demand. Motor systems currently consume some 65--80% of the industrial electricity in developing countries. Drawing on studies from Thailand, India, Brazil, China, Pakistan, and Costa Rica, we describe potential efficiency gains in various parts of the motor system, from the electricity delivery system through the motor to the point where useful work is performed. We report evidence of a significant electricity conservation potential. Most of the efficiency improvement methods we examine are very cost-effective from a societal viewpoint, but are generally not implemented due to various barriers that deter their adoption. Drawing on experiences in North America, we discuss a range of policies to overcome these barriers, including education, training, minimum efficiency standards, motor efficiency testing protocols, technical assistance programs, and financial incentives.

  4. Efficient Data-Structures and Algorithms for a Coloured Petri Nets Simulator

    DEFF Research Database (Denmark)

    Mortensen, Kjeld Høyer

    2001-01-01

    In this paper we describe how efficient data-structures and algorithms are used to dramatically improve the performance of a simulator for Coloured Petri Nets compared with earlier versions. We have improved the simulator with respect to three areas: Firstly we have improved the transition...... of other transitions. Secondly we have improved the data-structures which hold multi-sets for markings. A kind of weight-balanced trees, called BB-trees. are used instead of lists as in the original version of the simulator. Although this kind of trees are more difficult to maintain at run...... "recipe" which is specially generated and optimised for each individual transition. The improved simulator is implemented in both the Design/CPN and CPN tools software packages, and has been used in several industrial projects....

  5. Economic analysis of Brazilian policies for energy efficient electric motors

    International Nuclear Information System (INIS)

    Andrade, Cássio Tersandro de Castro; Pontes, Ricardo Silva Thé

    2017-01-01

    Brazil is leading several energy efficiency initiatives and has ambitious goals for 2030, according to the Brazilian National Energy Plan 2030. One of the main initiatives is the minimum efficiency performance standards (MEPS) program for energy-driven equipment and the electric motors appear as the most significant one (49% share of the total electricity consumption). The MEPS levels set new grades for efficiency, and then manufacturers and consumers have to conform to the new products and costs. Policy makers have to economically assess the effects of these MEPS in order to maintain the market stability. Since the benefits of this program come from future energy savings, this cost-effective analysis has to consider the parameters uncertainty and the results should reinforce the market players’ confidence. Thus, the goal of this work is, first, to analyze the economic viability of the MEPS transitions in Brazil considering the uncertainty of the parameters involved and then, to estimate the effects of this program on the energy savings goals for 2030. At the end, we also verify whether this investment in energy efficiency is competitive with other forms of investments in energy. - Highlights: • A cost-effectiveness method with uncertainty for efficiency program is presented. • Savings from electric motors MEPS program makes the 2030 Brazilian goals possible. • Electric motors MEPS program cost-effectiveness in Brazil is confirmed. • Saved energy cost from efficiency improvement is a competitive energy investment.

  6. Efficient emission fees in the US electricity sector

    International Nuclear Information System (INIS)

    Spencer Banzhaf, H.; Burtraw, Dallas; Palmer, Karen

    2004-01-01

    This paper provides new estimates of efficient emission fees for sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ) emissions in the US electricity sector. The estimates are obtained by coupling a detailed simulation model of the US electricity markets with an integrated assessment model that links changes in emissions with atmospheric transport, environmental endpoints, and valuation of impacts. Efficient fees are found by comparing incremental benefits with emission fee levels. National quantity caps that are equivalent to these fees also are computed, and found to approximate caps under consideration in the current multi-pollutant debate in the US Congress and the recent proposals from the Bush administration for the electricity industry. We also explore whether regional differentiation of caps on different pollutants is likely to enhance efficiency

  7. Analysis of the Fuel Efficiency of a Hybrid Electric Drive with an Electric Power Splitter

    OpenAIRE

    D. Čundev

    2008-01-01

    This paper presents the results of an analysis of the fuel efficiency of a hybrid electric car drive, with an electric power splitter based on a double rotor synchronous permanent magnet generator. The results have been obtained through a precisely determined mathematical model and by simulating the characteristics of all essential values for the entire drive. This work is related to the experimental working stand for electric and hybrid car drive research, which has been developed at the Fac...

  8. Efficiency and environmental factors in the US electricity transmission industry

    International Nuclear Information System (INIS)

    Llorca, Manuel; Orea, Luis; Pollitt, Michael G.

    2016-01-01

    The electricity industry in most developed countries has been restructured over recent decades with the aim of improving both service quality and firm performance. Regulated segments (e.g. transmission) still provide the infrastructure for the competitive segments and represent a significant share of the total price paid by final customers. However there is a lack of empirical studies that analyse firms' performance in the electricity transmission sector. In this paper an empirical analysis of US electricity transmission companies is conducted for the period 2001–2009. We use alternative stochastic frontier models that allow us to identify the determinants of firms' inefficiency. These models also permit us to control for weather conditions, potentially one of the most decisive uncontrollable factors in electricity transmission. Our results suggest that weather conditions clearly have an influence on transmission costs and that there is room for improvement in the management of US electricity transmission systems. Regulators should also be aware that more adverse conditions generate higher levels of inefficiency, and that achieving long-term efficiency improvements tends to worsen firms' short-term relative performance. - Highlights: • We analyse firms' performance in the US electricity transmission industry. • Alternative SFA models are estimated to identify determinants of firms' efficiency. • Our results indicate that firms' efficiency has declined and diverged over time. • We find that more adverse conditions generate higher levels of inefficiency.

  9. Saving, efficiency and management of electric sector demand

    International Nuclear Information System (INIS)

    Sanchez de Tembleque, L. J.

    2007-01-01

    Spanish economic model of development is based on energy consumption, and its main source is imported fossil fuels, which have some environmental and scarcity consequences in the mid term, among others. These problems could be reduced in two ways: economic activity reduction or energy efficiency improvement. In the presence of these possibilities, It may be desirable to bet for saving and energy efficiency, to maintain the economic development. This assignment analyzes the main available regulatory and social mechanisms to promote saving and energy efficiency in the power sector, like systems to internalize social costs in the electricity price, efficiency standards, and encourage the new saving culture. (Author) 15 refs

  10. Electric buses - An energy efficient urban transportation means

    Energy Technology Data Exchange (ETDEWEB)

    Kuehne, Reinhart [German Aerospace Center (DLR), Transportation Studies, Rutherfordstr. 2, 12489 Berlin (Germany)

    2010-12-15

    Bus transit systems with electric traction are an important contribution to the post fossil fuel mobility. Most renewable energy sources provide energy in the form of electricity. Electric motors thus have promise in the development of the way ''beyond oil''. The reactivation of trolley bus systems - grid bounded but also catenary free for short distances - paves this way. The design of modern trolley bus operations overcomes the existing disadvantages of conventional buses using fossil fuel. Germany has an efficient industry in this field, that offers braking energy recovery and energy storage in modern supercapacitors as well as technical and organisational innovations for a local emission free and a low noise transit system. Gentle but powerful when starting and braking, the trolley bus is cost effective and easy to integrate into an existing infrastructure. Such an electric bus system is ecological, customer-friendly and suitable for cities. It has a high economic efficiency and it also expands the traffic planning field towards an ecological future technology. This paper shows examples at home and abroad how electric buses achieve an energy solving modern urban traffic. It gives insights into technical developments of electric vehicle equipment, cateneries with fast driving handling characteristics and the use of plain electric and hybrid powertrains. (author)

  11. Toward a More Efficient and Innovative Electricity Sector in Russia

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Russia is in the process of one of the most ambitious electricity sector reforms ever undertaken, reflecting the importance of an efficient and reliable electricity sector for promoting economic activity, growth and community prosperity. The outcome of this process will have a substantial impact on Russia’s energy sector and longer-term economic performance. It will help to determine the nature and pace of investment and modernisation of the sector and will help to shape incentives for efficient, flexible and innovative operation and end-use.

  12. Energy Efficiency Comparison between Hydraulic Hybrid and Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Jia-Shiun Chen

    2015-05-01

    Full Text Available Conventional vehicles tend to consume considerable amounts of fuel, which generates exhaust gases and environmental pollution during intermittent driving cycles. Therefore, prospective vehicle designs favor improved exhaust emissions and energy consumption without compromising vehicle performance. Although pure electric vehicles feature high performance and low pollution characteristics, their limitations are their short driving range and high battery costs. Hybrid electric vehicles (HEVs are comparatively environmentally friendly and energy efficient, but cost substantially more compared with conventional vehicles. Hydraulic hybrid vehicles (HHVs are mainly operated using engines, or using alternate combinations of engine and hydraulic power sources while vehicles accelerate. When the hydraulic system accumulator is depleted, the conventional engine reengages; concurrently, brake-regenerated power is recycled and reused by employing hydraulic motor–pump modules in circulation patterns to conserve fuel and recycle brake energy. This study adopted MATLAB Simulink to construct complete HHV and HEV models for backward simulations. New European Driving Cycles were used to determine the changes in fuel economy. The output of power components and the state-of-charge of energy could be retrieved. Varying power component models, energy storage component models, and series or parallel configurations were combined into seven different vehicle configurations: the conventional manual transmission vehicle, series hybrid electric vehicle, series hydraulic hybrid vehicle, parallel hybrid electric vehicle, parallel hydraulic hybrid vehicle, purely electric vehicle, and hydraulic-electric hybrid vehicle. The simulation results show that fuel consumption was 21.80% lower in the series hydraulic hybrid vehicle compared to the series hybrid electric vehicle; additionally, fuel consumption was 3.80% lower in the parallel hybrid electric vehicle compared to the

  13. Efficient promotion of electricity production from offshore wind

    International Nuclear Information System (INIS)

    Panzer, Christian; Auer, Hans; Lettner, Georg

    2014-01-01

    Efficient promotion of electricity production from offshore wind stands in dynamic relationship with various influence factors, the most important of which are promotion instruments, topographic givens, regulation of grid connection, and supraregional market integration concepts. Using three case studies from different countries to highlight national differences in the promotion of offshore wind power plants the present analysis points out ways of improving the efficiency of promotion instruments.

  14. Analysis of the Fuel Efficiency of a Hybrid Electric Drive with an Electric Power Splitter

    Directory of Open Access Journals (Sweden)

    D. Čundev

    2008-01-01

    Full Text Available This paper presents the results of an analysis of the fuel efficiency of a hybrid electric car drive, with an electric power splitter based on a double rotor synchronous permanent magnet generator. The results have been obtained through a precisely determined mathematical model and by simulating the characteristics of all essential values for the entire drive. This work is related to the experimental working stand for electric and hybrid car drive research, which has been developed at the Faculty of Electrical Engineering (FEE at CTU in Prague. 

  15. Energy efficient motion control of the electric bus on route

    Science.gov (United States)

    Kotiev, G. O.; Butarovich, D. O.; Kositsyn, B. B.

    2018-02-01

    At present, the urgent problem is the reduction of energy costs of urban motor transport. The article proposes a method of solving this problem by developing an energy-efficient law governing the movement of an electric bus along a city route. To solve this problem, an algorithm is developed based on the dynamic programming method. The proposed method allows you to take into account the constraints imposed on the phase coordinates, control action, as well as on the time of the route. In the course of solving the problem, the model of rectilinear motion of an electric bus on a horizontal reference surface is considered, taking into account the assumptions that allow it to be adapted for the implementation of the method. For the formation of a control action in the equations of motion dynamics, an algorithm for changing the traction / braking torque on the wheels of an electric bus is considered, depending on the magnitude of the control parameter and the speed of motion. An optimal phase trajectory was obtained on a selected section of the road for the prototype of an electric bus. The article presents the comparison of simulation results obtained with the optimal energy efficient control law with the results obtained by a test driver. The comparison proved feasibility of the energy efficient control law for the automobile city electric transport.

  16. Enhanced policies for the improvement of electricity efficiencies

    International Nuclear Information System (INIS)

    Blok, Kornelis

    2005-01-01

    Energy-efficiency improvement is considered as an important option to limit greenhouse gas emissions. In this paper, the possibilities to implement new policies to improve the efficiency of electricity end-use are explored. The following policy actions are considered: - introduction of a '1 W standard' for standby power consumption of appliances;- incremental standards for large electric appliances;- design guidelines for small electric appliances;- a technology-forcing standard for lighting;- a motor-drive program;- a program directed at the reduction of electricity use during empty-office hours;- actual energy performance requirements for service-sector buildings. The implementation of these programs will contribute substantially to reaching greenhouse gas emission targets in the European Union (total estimated effect to be 200-350 Mton CO 2 emission reduction in the year 2020). However, to reach these targets a very substantial effort is required, both in terms of policy ambition, force of the applied instruments, and implementation efforts. In the case of electric appliances, regulatory instruments may need wider application. And, in order to attain the substantial potential savings in motor-drive systems, an effort comparable to the effort to promote renewable electricity in the European Union may be both justified and necessary

  17. Energy Efficiency in Electrical Systems: A Case Study of an ...

    African Journals Online (AJOL)

    pc

    2018-03-05

    Mar 5, 2018 ... Energy Efficiency in Electrical Systems: A Case. Study of an .... industries in Morocco have a medium-voltage billing bellow, which is ... the circulation of the reactive energy on the distribution ... High voltage drops. Indeed, for ...

  18. Energy efficiency and performance indicators of European electricity market

    Directory of Open Access Journals (Sweden)

    Constantin DUGULEANĂ

    2015-06-01

    Full Text Available The electric power system plays a vital role in the development of every country, ensuring the “fuel” which feeds its economic motor. The efficient functioning of this motor is essential for economy. The efficiency and the performances of electric power systems are reflected on the living level of population, through the money spent and the satisfaction level of their needs. The continuity of power distribution process, the good communication between the suppliers and consumers, the promptitude of interventions, the environment protection - all these are aspects characterizing the performance level of power distribution systems. The paper analyzes the evolution of quality indicators of power distribution systems both for countries’ level and for population on European market of electricity.

  19. Time-varying value of electric energy efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Mims, Natalie A.; Eckman, Tom; Goldman, Charles

    2017-06-30

    Electric energy efficiency resources save energy and may reduce peak demand. Historically, quantification of energy efficiency benefits has largely focused on the economic value of energy savings during the first year and lifetime of the installed measures. Due in part to the lack of publicly available research on end-use load shapes (i.e., the hourly or seasonal timing of electricity savings) and energy savings shapes, consideration of the impact of energy efficiency on peak demand reduction (i.e., capacity savings) has been more limited. End-use load research and the hourly valuation of efficiency savings are used for a variety of electricity planning functions, including load forecasting, demand-side management and evaluation, capacity and demand response planning, long-term resource planning, renewable energy integration, assessing potential grid modernization investments, establishing rates and pricing, and customer service. This study reviews existing literature on the time-varying value of energy efficiency savings, provides examples in four geographically diverse locations of how consideration of the time-varying value of efficiency savings impacts the calculation of power system benefits, and identifies future research needs to enhance the consideration of the time-varying value of energy efficiency in cost-effectiveness screening analysis. Findings from this study include: -The time-varying value of individual energy efficiency measures varies across the locations studied because of the physical and operational characteristics of the individual utility system (e.g., summer or winter peaking, load factor, reserve margin) as well as the time periods during which savings from measures occur. -Across the four locations studied, some of the largest capacity benefits from energy efficiency are derived from the deferral of transmission and distribution system infrastructure upgrades. However, the deferred cost of such upgrades also exhibited the greatest range

  20. Energy efficiency improvement of medical electric tools and devices

    Directory of Open Access Journals (Sweden)

    Meshkov Aleksandr S.

    2014-01-01

    Full Text Available With the ever-increasing volume of applications of various kinds of electric drives in all spheres of human activity, the issues in improving the efficiency of the electromechanical converters of electric energy, one of the most important components of the electric drive (ED, are becoming increasingly important. Such issues include reducing their weight and size, improving the functional characteristics of these devices to increase their operational life and reducing the cost of manufacture. Taking full advantage of these opportunities relates to the AC and DC single-phase commutator motor (SCM, which is widely used in regulated and high-speed motor drives in medical electric hand tools. The SCM is used in machinery where the load torque has a hyperbolic dependence on the rotational speed and the need to work with a large motor overload due to the “soft” mechanical characteristics of such motors.

  1. Net trophic transfer efficiencies of polychlorinated biphenyl congeners to lake trout (Salvelinus namaycush) from its prey

    Science.gov (United States)

    Madenjian, Charles P.; David, Solomon R.; Rediske, Richard R.; O’Keefe, James P.

    2012-01-01

    Lake trout (Salvelinus namaycush) were fed bloater (Coregonus hoyi) in eight laboratory tanks over a 135-d experiment. At the start of the experiment, four to nine fish in each tank were sacrificed, and the concentrations of 75 polychlorinated biphenyl (PCB) congeners within these fish were determined. Polychlorinated biphenyl congener concentrations were also determined in the 10 lake trout remaining in each of the eight tanks at the end of the experiment as well as in the bloater fed to the lake trout. Each lake trout was weighed at the start and the end of the experiment, and the amount of food eaten by the lake trout was recorded. Using these measurements, net trophic transfer efficiency (γ) from the bloater to the lake trout in each of the eight tanks was calculated for each of the 75 congeners. Results showed that γ did not vary significantly with the degree of chlorination of the PCB congeners, and γ averaged 0.66 across all congeners. However,γ did show a slight, but significant, decrease as logKOW increased from 6.0 to 8.2. Activity level of the lake trout did not have a significant effect on γ.

  2. Convergent Evolution towards High Net Carbon Gain Efficiency Contributes to the Shade Tolerance of Palms (Arecaceae.

    Directory of Open Access Journals (Sweden)

    Ren-Yi Ma

    Full Text Available Most palm species occur in the shaded lower strata of tropical rain forests, but how their traits relate to shade adaptation is poorly understood. We hypothesized that palms are adapted to the shade of their native habitats by convergent evolution towards high net carbon gain efficiency (CGEn, which is given by the maximum photosynthetic rate to dark respiration rate ratio. Leaf mass per area, maximum photosynthetic rate, dark respiration and N and P concentrations were measured in 80 palm species grown in a common garden, and combined with data of 30 palm species growing in their native habitats. Compared to other species from the global leaf economics data, dicotyledonous broad-leaved trees in tropical rainforest or other monocots in the global leaf economics data, palms possessed consistently higher CGEn, achieved by lowered dark respiration and fairly high foliar P concentration. Combined phylogenetic analyses of evolutionary signal and trait evolution revealed convergent evolution towards high CGEn in palms. We conclude that high CGEn is an evolutionary strategy that enables palms to better adapt to shady environments than coexisting dicot tree species, and may convey advantages in competing with them in the tropical forest understory. These findings provide important insights for understanding the evolution and ecology of palms, and for understanding plant shade adaptations of lower rainforest strata. Moreover, given the dominant role of palms in tropical forests, these findings are important for modelling carbon and nutrient cycling in tropical forest ecosystems.

  3. Potential benefits from improved energy efficiency of key electrical products: The case of India

    International Nuclear Information System (INIS)

    McNeil, Michael A.; Iyer, Maithili; Meyers, Stephen; Letschert, Virginie E.; McMahon, James E.

    2008-01-01

    The economy of the world's second most populous country continues to grow rapidly, bringing prosperity to a growing middle class while further straining an energy infrastructure already stretched beyond capacity. At the same time, efficiency policy initiatives have gained a foothold in India, and promise to grow in number over the coming years. This paper considers the maximum cost-effective potential of efficiency improvement for key energy-consuming products in the Indian context. The products considered are: household refrigerators, window air conditioners, motors and distribution transformers. Together, these products account for about 27% of delivered electricity consumption in India. The analysis estimates the minimum Life-Cycle Cost option for each product class, according to use patterns and prevailing customer marginal rates in each sector. This option represents an efficiency improvement ranging between 12% and 60%, depending on product class. If this level of efficiency was achieved starting in 2010, we estimate that total electricity consumption in India could be reduced by 4.7% by 2020, saving over 74 million tons of oil equivalent and over 246 million tons of carbon dioxide emissions. Net present financial savings of this efficiency improvement totals 8.1 billion dollars

  4. Energy efficiency improvements in electric motors and drives

    Energy Technology Data Exchange (ETDEWEB)

    Bertoldi, P. [Commission of the European Communities, Brussels (Belgium). Directorate General for Energy; Ameida, A.T. de [Coimbra Univ. (Portugal). Dept. de Engenharia Electrotecnica; Falkner, H. [eds.] [AEA Technolgy, Harwell (United Kingdom). ETSU

    2000-07-01

    This book covers the state of the art of energy-efficient electric motor technologies, which can be used now and in the near future to achieve significant and cost-effective energy savings. Recent developments in advanced motor technologies by some of the largest manufacturers of motors and drives are also presented. Although energy-efficient motor technologies can save a huge amount of electricity, they still have not been widely adopted. The barriers which can hinder the adoption of those technologies are presented. Policies and programmes to promote the large scale penetration of energy-efficient technologies and the market transformation are featured in the book, describing the experiences carried out in different parts of the world. This extensive coverage includes contributions from relevant institutions in the European Union, North America, Latin America, Japan, Australia and New Zealand. (orig.)

  5. Efficient pricing and investment in electricity markets with intermittent resources

    International Nuclear Information System (INIS)

    Chao, Hung-po

    2011-01-01

    Facing growing technological and environmental challenges, the electricity industry needs effective pricing mechanism to promote efficient risk management and investment decisions. In a restructured electricity market with competitive wholesale prices and traditionally regulated retail rates, however, there are technical and institutional barriers that prevent dynamic pricing with price responsive demand. In regions with limited energy storage capacity, intermittent renewable resources present special challenges. This could adversely affect the effectiveness of public policies causing inefficient investments in energy technologies. In this paper, we present an updated economic model of pricing and investment in restructured electricity market and use the model in a simulation study for an initial assessment of renewable energy strategy and alternative pricing mechanisms. A key objective of the study is to shed light on the policy issues so that effective decisions can be made to improve efficiency. - Highlights: → Renewable resources present special challenges in regions with limited energy storage capacity. → This paper presents an updated economic model of pricing and investment in restructured electricity market. → A simulation study assesses renewable energy strategy and alternative pricing mechanisms. → The study results inform policy decisions to improve efficient investments in energy technologies.

  6. Development of an International Electric Cooperative Initiative on Energy Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Paul Clark; David South

    2004-05-01

    NRECA conceived of the International Electric Cooperative Initiative on Energy Efficiency (IECIEE) in order to provide an ongoing means of contributing voluntary actions on greenhouse gas emissions mitigation as an integral component of its international programs and projects. This required designing the IECIEE to be integrated directly with the core interests and attributes of participating cooperatives in the U.S. and Latin America, which was the initial focus area selected for the IECIEE. In the case of NRECA International, the core interests related to promoting and strengthening the electric cooperative model, which has proved highly successful in maximizing operational efficiencies in electric power generation, distribution and retailing, as compared to government-owned entities. The approach involved three basic components: (i) establishing the IECIEE mechanism, which involved setting up a functioning organizational vehicle providing for investment, management, and emissions credit accounting; (ii) developing a portfolio of projects in countries where NRECA International could effectively implement the broader mandate of cooperative development as energy efficient suppliers and distributors of electrical energy; and (iii) conducting outreach to obtain the commitment of participants and resources from U.S. and Latin American cooperatives and partnering agencies in the development financing community.

  7. Efficient forced vibration reanalysis method for rotating electric machines

    Science.gov (United States)

    Saito, Akira; Suzuki, Hiromitsu; Kuroishi, Masakatsu; Nakai, Hideo

    2015-01-01

    Rotating electric machines are subject to forced vibration by magnetic force excitation with wide-band frequency spectrum that are dependent on the operating conditions. Therefore, when designing the electric machines, it is inevitable to compute the vibration response of the machines at various operating conditions efficiently and accurately. This paper presents an efficient frequency-domain vibration analysis method for the electric machines. The method enables the efficient re-analysis of the vibration response of electric machines at various operating conditions without the necessity to re-compute the harmonic response by finite element analyses. Theoretical background of the proposed method is provided, which is based on the modal reduction of the magnetic force excitation by a set of amplitude-modulated standing-waves. The method is applied to the forced response vibration of the interior permanent magnet motor at a fixed operating condition. The results computed by the proposed method agree very well with those computed by the conventional harmonic response analysis by the FEA. The proposed method is then applied to the spin-up test condition to demonstrate its applicability to various operating conditions. It is observed that the proposed method can successfully be applied to the spin-up test conditions, and the measured dominant frequency peaks in the frequency response can be well captured by the proposed approach.

  8. What happened to efficiency in electricity industries after reforms?

    International Nuclear Information System (INIS)

    Erdogdu, Erkan

    2011-01-01

    The last two decades have witnessed widespread power market reforms in both developed and developing countries that have cost billions of dollars. Among the key aims (and assumptions) of these reforms, there has always been realization of improvements in power sector efficiency. This paper questions the validity of this hypothesis. Using panel data from 92 countries covering the period 1982-2008, empirical models are developed and analyzed. The research findings suggest that the impact of the reforms on electricity industry performance is statistically significant but also limited. The results imply that, after controlling for country-specific variables, application of liberal market models in electricity industries slightly increases efficiency in power sector. Besides, we detect a positive relationship between reform process and the percentage share of network (transmission and distribution) losses in total electricity supplied, meaning that as countries take more reform steps the network losses as a fraction of power generated tend to increase. Moreover, the study puts forward that income level and other country specific features are more important determinants of industry efficiency than the reform process. Overall, contrary to expectations of substantial increases in sector efficiency, the paper concludes that introducing a decentralized market model with competition in the electricity sector has a limited increasing effect on power industry performance. - Highlights: → The paper questions whether the reforms increase efficiency in the power sector. → Panel data from 92 countries covering the period 1982-2008 are employed. → Models are developed by fixed/random effect panel data estimation methods. → The paper concludes the reforms have a limited effect on the industry performance. → We also find that as countries take more reform steps the network losses increase.

  9. Methods of formation of efficiency indexes of electric power sources integration in regional electric power systems

    International Nuclear Information System (INIS)

    Marder, L.I.; Myzin, A.I.

    1993-01-01

    A methodic approach to the grounding of the integration process efficiency within the Unified electric power system is given together with the selection of a rational areal structure and concentration of power-generating source capacities. Formation of an economic functional according to alternative scenavies including the cost components taking account of the regional interests is considered. A method for estimation and distribution of the effect from electric power production integration in the power systems under new economic conditions is proposed

  10. Improving timeliness and efficiency in the referral process for safety net providers: application of the Lean Six Sigma methodology.

    Science.gov (United States)

    Deckard, Gloria J; Borkowski, Nancy; Diaz, Deisell; Sanchez, Carlos; Boisette, Serge A

    2010-01-01

    Designated primary care clinics largely serve low-income and uninsured patients who present a disproportionate number of chronic illnesses and face great difficulty in obtaining the medical care they need, particularly the access to specialty physicians. With limited capacity for providing specialty care, these primary care clinics generally refer patients to safety net hospitals' specialty ambulatory care clinics. A large public safety net health system successfully improved the effectiveness and efficiency of the specialty clinic referral process through application of Lean Six Sigma, an advanced process-improvement methodology and set of tools driven by statistics and engineering concepts.

  11. Actions to promote energy efficient electric motors. Motors study group

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, A.T. de [Coimbra Univ. (PT). Inst. of Systems and Robotics (ISR)

    1996-10-01

    Motor electricity consumption is influenced by many factors including: motor efficiency, motor speed controls, power supply quality, harmonics, systems oversizing, distribution network, mechanical transmission system, maintenance practices, load management and cycling, and the efficiency of the end-use device (e.g. fan, pump, etc.). Due to their importance, an overview of these factors is presented in this report. This study also describes the electricity use in the industrial and tertiary sectors and the electricity consumption associated with the different types of electric motors systems in the Member States of the European Union, as well as estimated future evolution until 2010. The studies for individual countries were carried out by the different partners of the motors study group at a previous stage. The study has found that there is a lack of accurate information about the motor electricity consumption, installed motor capacity and the motor market in almost all the European Union countries and only some general statistical sources are available. There is little field data, which is mainly available in Denmark, France, Italy and the Netherlands. Due to this lack of primary information, some common assumptions were made, based on the experience of the members of the study group. This lack of end-use characterisation data shows the need for improvement from the point of view of current knowledge. It is therefore recommended that further research is undertaken to arrive at more accurate figures. These could be the basis for a better understanding for motor use in practice and - as a consequence - for a more precise appraisal of potentials and barriers to energy efficiency. (orig.)

  12. Efficiency and regulation of the Slovenian electricity distribution companies

    International Nuclear Information System (INIS)

    Filippini, Massimo; Hrovatin, Nevenka; Zoric, Jelena

    2004-01-01

    The Slovenian Energy Law, adopted in 1999, has opened the internal market to competition up to 64% of the final consumption. The opening of the internal market to foreign competition is envisaged for 2003. With regard to the methodology of price regulation, the Energy Law introduces the 'price-cap' regulation, which aims to give firms incentive for cost reduction. To provide information for effective price regulation, we estimated a cost frontier function on a sample of Slovenian electricity distribution utilities over the 1991-2000 period. The estimated efficient frontier could be used by Slovenian regulatory agency as a benchmark to regulate network access prices. Our results show that Slovenian distribution companies are cost inefficient. We have also proved the presence of increasing returns to scale with most utilities not achieving the minimum efficient scale. Thus, the Slovenian regulatory authority should consider how to induce mergers of small electricity distribution utilities into larger units

  13. Joint environmental and cost efficiency analysis of electricity generation

    International Nuclear Information System (INIS)

    Welch, Eric; Barnum, Darold

    2009-01-01

    Fossil-fuel based electricity generation produces the largest proportion of human-related carbon pollution in the United States. Hence, fuel choices by steam plants are key determinants of the industry's impact on national and global greenhouse gas emissions, and key foci for climate change policy. Yet, little research has been done to examine the economic and environmental tradeoffs among the different types of fuels that are used by these plants. This paper applies a Data Envelopment Analysis procedure that incorporates the materials balance principle to estimate the allocations of coal, gas and oil inputs that minimize carbon emissions and costs. Using EIA 906 and FERC 423 data, the paper estimates cost/carbon tradeoffs facing two sets of plants: those that use coal and gas inputs, and those that use coal, gas and oil inputs. Findings for our three-input sample show that there would be a 79% increase in cost for moving from the cost-efficient point to the carbon efficient point, while there would be a 38% increase in carbon for moving from the carbon efficient point to the cost-efficient point. These conclusions indicate that, in general, the gap between efficient cost and efficient environmental production is wide, and would require substantial policy intervention, technological change or market adjustment before it could be narrowed. However, our examination of individual plants shows that what is true in general is often not true for specific plants. Some plants that are currently less efficient than those on the production frontier could produce the same amount of electricity with less carbon output and less fuel input. Additionally, many plants on the production frontier could improve both cost and carbon efficiency by changing their mixture of fossil-fuel inputs. (author)

  14. Energy-efficiency instruments in the electricity area

    International Nuclear Information System (INIS)

    Hammer, S.; Oettli, B.; Schneider, Ch.; Iten, R.; Peherstorfer, N.

    2007-06-01

    This comprehensive report for the Swiss Federal Office of Energy (SFOE) describes a mix of instruments that could increase the efficiency of electricity usage in Switzerland. The basis for the development of these instruments - the experience gained in Europe in this area - is discussed. Explicitly not discussed are energy and electricity steering taxes, which could also be part of a future instrument-mix. The measures suggested include the setting of compulsory long-term reduction targets that are to form the basis for strategies and measures to be taken in particular areas and the development of an appropriate instrument-mix for this purpose. These could include regulations and labels, a national fund and certificate trading. Suppliers of electricity could be committed to increasing the efficiency of electricity use and national programmes could also attempt to influence consumer habits. The instruments should, according to the authors, be based on the existing legal framework and use know-how and structures that are already available

  15. Intercalibration of MOCNESS and Bongo nets: Assessing relative efficiency for ichthyoplankton

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The evaluation in catchability of egg and larval fish with the 0.61-m Bongo and the 1-m2 Multiple Opening and Closing Net Environmental Sensing System (MOCNESS) was...

  16. The neuro vector engine : flexibility to improve convolutional net efficiency for wearable vision

    NARCIS (Netherlands)

    Peemen, M.C.J.; Shi, R.; Lal, S.; Juurlink, B.H.H.; Mesman, B.; Corporaal, H.

    2016-01-01

    Deep Convolutional Networks (ConvNets) are currently superior in benchmark performance, but the associated demands on computation and data transfer prohibit straightforward mapping on energy constrained wearable platforms. The computational burden can be overcome by dedicated hardware accelerators,

  17. Chapter 21: Estimating Net Savings - Common Practices. The Uniform Methods Project: Methods for Determining Energy Efficiency Savings for Specific Measures

    Energy Technology Data Exchange (ETDEWEB)

    Kurnik, Charles W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Violette, Daniel M. [Navigant, Boulder, CO (United States); Rathbun, Pamela [Tetra Tech, Madison, WI (United States)

    2017-11-02

    This chapter focuses on the methods used to estimate net energy savings in evaluation, measurement, and verification (EM and V) studies for energy efficiency (EE) programs. The chapter provides a definition of net savings, which remains an unsettled topic both within the EE evaluation community and across the broader public policy evaluation community, particularly in the context of attribution of savings to a program. The chapter differs from the measure-specific Uniform Methods Project (UMP) chapters in both its approach and work product. Unlike other UMP resources that provide recommended protocols for determining gross energy savings, this chapter describes and compares the current industry practices for determining net energy savings but does not prescribe methods.

  18. Renewable energy and energy efficiency in liberalized European electricity markets

    International Nuclear Information System (INIS)

    Wohlgemuth, Norbert

    2000-01-01

    Given the projected growth in global energy demand, renewable energy (RE) and energy efficiency (EE) play a crucial role in the attainment of the environmental dimension of sustainable development. Policy mechanisms to promote RE and EE have been justified on the rationale of market failure, which prevents price signals alone from being sufficient to induce consumers to implement the socially optimal level. The paper shows driving forces for increasing competition in the electricity supply industry and discusses the implication of electricity industry liberalisation on RE/EE activities. Policies of the European Commission to promote RE/EE are presented, including a more detailed description of the experience made in the United Kingdom. Conclusions are that the new market structure may be too short sighted to stimulate RE and EE activities and that the design of policies should be compatible with the new market-orientated structure of the electricity industry. If implemented properly, and compatible with the competitive market organisation, electricity supply liberalisation could pave the way for 'sustainable electricity' in the European Union. (Author)

  19. Lightweight High Efficiency Electric Motors for Space Applications

    Science.gov (United States)

    Robertson, Glen A.; Tyler, Tony R.; Piper, P. J.

    2011-01-01

    Lightweight high efficiency electric motors are needed across a wide range of space applications from - thrust vector actuator control for launch and flight applications to - general vehicle, base camp habitat and experiment control for various mechanisms to - robotics for various stationary and mobile space exploration missions. QM Power?s Parallel Path Magnetic Technology Motors have slowly proven themselves to be a leading motor technology in this area; winning a NASA Phase II for "Lightweight High Efficiency Electric Motors and Actuators for Low Temperature Mobility and Robotics Applications" a US Army Phase II SBIR for "Improved Robot Actuator Motors for Medical Applications", an NSF Phase II SBIR for "Novel Low-Cost Electric Motors for Variable Speed Applications" and a DOE SBIR Phase I for "High Efficiency Commercial Refrigeration Motors" Parallel Path Magnetic Technology obtains the benefits of using permanent magnets while minimizing the historical trade-offs/limitations found in conventional permanent magnet designs. The resulting devices are smaller, lower weight, lower cost and have higher efficiency than competitive permanent magnet and non-permanent magnet designs. QM Power?s motors have been extensively tested and successfully validated by multiple commercial and aerospace customers and partners as Boeing Research and Technology. Prototypes have been made between 0.1 and 10 HP. They are also in the process of scaling motors to over 100kW with their development partners. In this paper, Parallel Path Magnetic Technology Motors will be discussed; specifically addressing their higher efficiency, higher power density, lighter weight, smaller physical size, higher low end torque, wider power zone, cooler temperatures, and greater reliability with lower cost and significant environment benefit for the same peak output power compared to typically motors. A further discussion on the inherent redundancy of these motors for space applications will be provided.

  20. Efficient integration of renewable energies in the German electricity market

    International Nuclear Information System (INIS)

    Nabe, C.A.

    2006-01-01

    Liberalisation of the electricity sector aims to carry out coordination tasks within the system by markets and market prices. This study examines how markets need to be designed to carry out coordination tasks caused by integration of renewable energies in an efficient way. This question is applied to the German electricity system and recommendations are derived from identified deficits. The examination uses the structure-conduct-performance approach of industrial organisation economics. Integration of renewable energies does not result in entirely new coordination tasks but complicates those that exist in any electricity supply system. Within the short-term coordination tasks provision and operation of reserve capacity is affected by renewable energies. Long-term coordination means that the relation between fixed and variable costs of generators as well as generator flexibility has to be adjusted to the characteristics of renewable energies. The relevant short-term coordination task with the network is congestion management. In the long run costs of grid expansion and permanent congestion management have to be balanced. For the execution of short-run coordination tasks integrated and centralised market architectures are superior to decentralised architectures. The increase of short-term coordination tasks due to renewable energies caused by inflexibilities of consumers and conventional generators results in more information that has to be considered. By centralising that information in one market, an increase in productive efficiency can be obtained. In Germany the increased coordination tasks are determined by the integration of wind generators into the electricity system. The present German market architecture results in inefficiencies in short-term coordination. This is demonstrated by an analysis of procedural rules and prices of the ancillary service markets. They demonstrate that market performance is low and significant deviations from competitive prices

  1. Efficiency evaluation of the state owned electric utilities in India

    International Nuclear Information System (INIS)

    Thakur, Tripta; Deshmukh, S.G.; Kaushik, S.C.

    2006-01-01

    This paper presents a framework for accessing comparative efficiencies of Indian State Owned Electric Utilities (SOEU), which have been mainly responsible for the generation, distribution and transmission of electricity in India. Performance of 26 utilities was evaluated using the non-parametric technique of Data Envelopment Analysis (DEA), and the impact of scale on the efficiency scores was also evaluated. The results indicate that the performance of several SOEUs is sub-optimal, suggesting the potential for significant cost reductions. Separate benchmarks were derived for possible reductions in employees' number, and the results indicate that several utilities deploy a much larger number of employees than that required by a best practice utility, and significant savings are possible on this account. It was also found that the bigger utilities display greater inefficiencies and have distinct scale inefficiencies. Exploiting scale efficiencies by suitable restructuring and unbundling of SOEUs are therefore crucial measures that may foster efficiencies in the SOEUs. The paper discusses these results in the context of related policy issues

  2. Improving distribution efficiency of electrical network using geo-electrical options. A case study in a rural area of Assam (India)

    Energy Technology Data Exchange (ETDEWEB)

    Hazarika, S.; Hiloidhari, M.; Baruah, D.C. [Energy Conservation Laboratory, Department of Energy, Tezpur University, Tezpur, Assam (India)

    2012-11-15

    Reduction of electricity distribution loss is a major area of focus in India. This paper aims to investigate geo-electrical options to improve distribution efficiency of electrical network. Distribution efficiencies corresponding to several possible electrical network options are assessed using Geographical Information System (GIS) integrated electrical theory. An existing electrical distribution network of a rural area in Assam (India) is considered for the present investigation. Information related to characteristics of loads, features of conductors, and transformers of the existing network are used for this investigation. The line losses of the three existing transformers are estimated at about 36, 20, and 3 % of their respective connected loads. Longer distribution lines associated with higher loads are the causes of higher line losses. Using basic electrical theory and GIS tools, it is found that line losses can be reduced in the existing distribution system through management of distribution transformer and reconductoring. Two alternative locations for each of the three transformers are identified for optimal management of distribution transformers. Similarly, five different types of commercially available conductors are identified for possible reconductoring to reduce line loss. The economic viability of reconductoring of distribution lines are also assessed through an economic analysis. Net present values of total expenditure comprising purchase prices of conductor and cost attributed to line losses are estimated considering 30 years of useful life. The existing conductor has the worst economic merit, though it is the cheapest amongst all. A net saving of about USD 24,084 is possible through the best choice of distribution conductor for the village.

  3. Calculating systems-scale energy efficiency and net energy returns: A bottom-up matrix-based approach

    International Nuclear Information System (INIS)

    Brandt, Adam R.; Dale, Michael; Barnhart, Charles J.

    2013-01-01

    In this paper we expand the work of Brandt and Dale (2011) on ERRs (energy return ratios) such as EROI (energy return on investment). This paper describes a “bottom-up” mathematical formulation which uses matrix-based computations adapted from the LCA (life cycle assessment) literature. The framework allows multiple energy pathways and flexible inclusion of non-energy sectors. This framework is then used to define a variety of ERRs that measure the amount of energy supplied by an energy extraction and processing pathway compared to the amount of energy consumed in producing the energy. ERRs that were previously defined in the literature are cast in our framework for calculation and comparison. For illustration, our framework is applied to include oil production and processing and generation of electricity from PV (photovoltaic) systems. Results show that ERR values will decline as system boundaries expand to include more processes. NERs (net energy return ratios) tend to be lower than GERs (gross energy return ratios). External energy return ratios (such as net external energy return, or NEER (net external energy ratio)) tend to be higher than their equivalent total energy return ratios. - Highlights: • An improved bottom-up mathematical method for computing net energy return metrics is developed. • Our methodology allows arbitrary numbers of interacting processes acting as an energy system. • Our methodology allows much more specific and rigorous definition of energy return ratios such as EROI or NER

  4. A combined sustainability index for electricity efficiency measures

    International Nuclear Information System (INIS)

    Goldrath, T.; Ayalon, O.; Shechter, M.

    2015-01-01

    One of the most substantial tools that serve decision makers in their efforts to reduce greenhouse gas emissions includes energy efficiency measures that in most cases benefit from governmental assistance for achieving electricity consumption reduction goals. This paper examines five energy efficiency measures, defining a combined sustainability index. A multi-criteria analysis of five predefined indices was developed (economic, environmental, technology, social and political), providing a combined index for each measure and a tool for identifying the preferred measure within a specific situation, based on its total sustainability score. In this research, a case study was conducted and the preferred measure was found to be municipal street lighting systems, based on its high political and social scores, and its relatively high installation potential. The second choice would be replacement of chillers in the industrial sector, and the least favorable measure is the replacement of water pumps in the water sector. The methodology described brings into account the technological specifications of the measure implemented, and the specific national conditions under which it is implemented. - Highlights: • A MCDA of five indices was developed to define a combined sustainability index. • Criteria defined were environment, technology, economy, social and political. • Five energy efficiency measures were rated, based on their total sustainability score. • Measures were in five main electricity consumption sectors. • The preferred measure found in the case study was municipal street lighting systems.

  5. SciNet: Lessons Learned from Building a Power-efficient Top-20 System and Data Centre

    International Nuclear Information System (INIS)

    Loken, Chris; Gruner, Daniel; Groer, Leslie; Peltier, Richard; Bunn, Neil; Craig, Michael; Henriques, Teresa; Dempsey, Jillian; Yu, Ching-Hsing; Chen, Joseph; Dursi, L Jonathan; Chong, Jason; Northrup, Scott; Pinto, Jaime; Knecht, Neil; Van Zon, Ramses

    2010-01-01

    SciNet, one of seven regional HPC consortia operating under the Compute Canada umbrella, runs Canada's first and third fastest computers (as of June 2010) in a state-of-the-art, highly energy-efficient datacentre with a Power Usage Effectiveness (PUE) design-point of 1.16. Power efficiency, computational 'bang for the buck' and system capability for a handful of flagship science projects were important criteria in choosing the nature of the computers and the data centre itself. Here we outline some of the lessons learned in putting together the systems and the data centre that hosts Canada's fastest computer to date.

  6. Efficient conversion of solar energy to biomass and electricity.

    Science.gov (United States)

    Parlevliet, David; Moheimani, Navid Reza

    2014-01-01

    The Earth receives around 1000 W.m(-2) of power from the Sun and only a fraction of this light energy is able to be converted to biomass (chemical energy) via the process of photosynthesis. Out of all photosynthetic organisms, microalgae, due to their fast growth rates and their ability to grow on non-arable land using saline water, have been identified as potential source of raw material for chemical energy production. Electrical energy can also be produced from this same solar resource via the use of photovoltaic modules. In this work we propose a novel method of combining both of these energy production processes to make full utilisation of the solar spectrum and increase the productivity of light-limited microalgae systems. These two methods of energy production would appear to compete for use of the same energy resource (sunlight) to produce either chemical or electrical energy. However, some groups of microalgae (i.e. Chlorophyta) only require the blue and red portions of the spectrum whereas photovoltaic devices can absorb strongly over the full range of visible light. This suggests that a combination of the two energy production systems would allow for a full utilization of the solar spectrum allowing both the production of chemical and electrical energy from the one facility making efficient use of available land and solar energy. In this work we propose to introduce a filter above the algae culture to modify the spectrum of light received by the algae and redirect parts of the spectrum to generate electricity. The electrical energy generated by this approach can then be directed to running ancillary systems or producing extra illumination for the growth of microalgae. We have modelled an approach whereby the productivity of light-limited microalgae systems can be improved by at least 4% through using an LED array to increase the total amount of illumination on the microalgae culture.

  7. Development of electrical efficiency measurement techniques for 10 kW-class SOFC system: Part I. Measurement of electrical efficiency

    International Nuclear Information System (INIS)

    Tanaka, Yohei; Momma, Akihiko; Kato, Ken; Negishi, Akira; Takano, Kiyonami; Nozaki, Ken; Kato, Tohru

    2009-01-01

    Measurement techniques to estimate electrical efficiency of 10 kW-class SOFC systems fueled by town-gas were developed and demonstrated for a system developed by Kansai Electric Power Company and Mitsubishi Materials Corporation under a NEDO project. Higher heating value of the fuel was evaluated with a transportable gas sampling unit and conventional gas chromatography in AIST laboratory with thermal-conductivity and flame-ionization detectors, leading to mean value 44.69 MJ m -3 on a volumetric base for ideal-gas at the standard state (0 deg. C, 101.325 kPa). Mass-flow-rate of the fuel was estimated as 33.04 slm with a mass-flow meter for CH 4 , which was calibrated to correct CH 4 flow-rate and effect of sensitivity change and to obtain conversion factor from CH 4 to town-gas. Without calibration, systematic effect would occur by 8% in flow-rate measurement in the case for CH 4 . Power output was measured with a precision power analyzer, a virtual three phase starpoint adapter, and tri-axial shunts. Power of fundamental wave (60 Hz) was estimated as 10.14 kW, considering from total active power, total higher harmonic distortion factor, and power consumption at the starpoint adapter. The electrical efficiency was presumed to be 41.2% (HHV), though this mean value will be complete only when uncertainty estimation is accompanied

  8. A differential dielectric spectroscopy setup to measure the electric dipole moment and net charge of colloidal quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Kortschot, R. J.; Bakelaar, I. A.; Erné, B. H.; Kuipers, B. W. M., E-mail: B.W.M.Kuipers@uu.nl [Van ' t Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute for Nanomaterials Science, Utrecht University, Padualaan 8, 3584 CH Utrecht (Netherlands)

    2014-03-15

    A sensitive dielectric spectroscopy setup is built to measure the response of nanoparticles dispersed in a liquid to an alternating electric field over a frequency range from 10{sup −2} to 10{sup 7} Hz. The measured complex permittivity spectrum records both the rotational dynamics due to a permanent electric dipole moment and the translational dynamics due to net charges. The setup consists of a half-transparent capacitor connected in a bridge circuit, which is balanced on pure solvent only, using a software-controlled compensating voltage. In this way, the measured signal is dominated by the contributions of the nanoparticles rather than by the solvent. We demonstrate the performance of the setup with measurements on a dispersion of colloidal CdSe quantum dots in the apolar liquid decalin.

  9. A differential dielectric spectroscopy setup to measure the electric dipole moment and net charge of colloidal quantum dots.

    Science.gov (United States)

    Kortschot, R J; Bakelaar, I A; Erné, B H; Kuipers, B W M

    2014-03-01

    A sensitive dielectric spectroscopy setup is built to measure the response of nanoparticles dispersed in a liquid to an alternating electric field over a frequency range from 10(-2) to 10(7) Hz. The measured complex permittivity spectrum records both the rotational dynamics due to a permanent electric dipole moment and the translational dynamics due to net charges. The setup consists of a half-transparent capacitor connected in a bridge circuit, which is balanced on pure solvent only, using a software-controlled compensating voltage. In this way, the measured signal is dominated by the contributions of the nanoparticles rather than by the solvent. We demonstrate the performance of the setup with measurements on a dispersion of colloidal CdSe quantum dots in the apolar liquid decalin.

  10. Energy efficiency and CO2: is electricity the key factor?

    Energy Technology Data Exchange (ETDEWEB)

    Bamberger, Y.

    2007-07-01

    Europe must face soon to the depletion of fossil energy resources. Efficiency in end energy uses is a key to prepare this challenge. First, the report shows that significant energy efficiency capacities remain in the main economy sectors in France and Europe: buildings, industry, transportation. The key technologies, mainly electricity-driven, are briefly presented, together with the related main tracks for R and D: heat pumps, thermal insulation, induction and mechanical vapour compression for industry, plugged hybrid vehicle, LED sources for lighting. Their ability to decrease CO2 emissions is shown. Control equipment and users behaviour are pointed out, mainly with the key role of price energy with recent French experience : load shifting, peak shaving. Finally, the report shows that a firm policy, based on high performance equipments, could lead to a significant decrease of energy needs in France around 2030.

  11. Is deintegrated electric generation efficient; A proposed empirical reserach framework

    Energy Technology Data Exchange (ETDEWEB)

    Fox-Penner, P S [Charles River Associates Incorporated, Boston, Massachusetts (US)

    1990-01-01

    Partial or complete deregulation of public utility industries, which until recently were regulated even in market-driven economics such as the U.S. are examined. The causes and cures of this phenomenon are discussed. The purpose is to present a framework for examining empirically the net benefits to consumers from one particular form of public utility ''deregulation'': separating or deintegrating electricity generators from transmitters, and deregulating the former. The framework has been developed for this application because U.S. public utility law has permitted this particular form of ''deregulation'' to exist alongside traditional utilities for the past ten years. Hence, data are now available for comparing regulated and deregulated power generators and their interaction with the transmission system. More generally, however, the purpose of this article is to argue that the benefits of regulatory change in public utility industries must be examined on a comprehensive basis. It is not sufficient to examine one stage of the vertical production chain and conclude that deregulation will improve or hinder its performance. Rather, the long-range benefits of various industry regimes should be carefully examined from the standpoint of the consumer at the downstream end of the production process. (author) 41 refs.

  12. System and method to determine electric motor efficiency using an equivalent circuit

    Science.gov (United States)

    Lu, Bin [Kenosha, WI; Habetler, Thomas G [Snellville, GA

    2011-06-07

    A system and method for determining electric motor efficiency includes a monitoring system having a processor programmed to determine efficiency of an electric motor under load while the electric motor is online. The determination of motor efficiency is independent of a rotor speed measurement. Further, the efficiency is based on a determination of stator winding resistance, an input voltage, and an input current. The determination of the stator winding resistance occurs while the electric motor under load is online.

  13. Gestió de factures electròniques TFC Microsoft .NET

    OpenAIRE

    Moreno Merino, Joan Manel

    2008-01-01

    El projecte genera un entorn personalitzat de gestió de factures electròniques utilitzant Visual Studio Tools, l¿entorn permet gestionar les bases de dades dels clients i dels productes oferts, generar factures i enviar-les via correu electrònic als clients en diferents formats (PDF o Word). El proyecto genera un entorno personalizado de gestión de facturas electrónicas utilizando Visual Studio Tools, el entorno permite gestionar las bases de datos de los clientes y de los productos ofreci...

  14. Amorphous and Nanocomposite Materials for Energy-Efficient Electric Motors

    Science.gov (United States)

    Silveyra, Josefina M.; Xu, Patricia; Keylin, Vladimir; DeGeorge, Vincent; Leary, Alex; McHenry, Michael E.

    2016-01-01

    We explore amorphous soft-magnetic alloys as candidates for electric motor applications. The Co-rich system combines the benefits of low hysteretic and eddy-current losses while exhibiting negligible magnetostriction and robust mechanical properties. The amorphous precursors can be devitrified to form nanocomposite magnets. The superior characteristics of these materials offer the advantages of ease of handling in the manufacturing processing and low iron losses during motor operation. Co-rich amorphous ribbons were laser-cut to build a stator for a small demonstrator permanent-magnet machine. The motor was tested up to ~30,000 rpm. Finite-element analyses proved that the iron losses of the Co-rich amorphous stator were ~80% smaller than for a Si steel stator in the same motor, at 18,000 rpm (equivalent to an electric frequency of 2.1 kHz). These low-loss soft magnets have great potential for application in highly efficient high-speed electric machines, leading to size reduction as well as reduction or replacement of rare earths in permanent-magnet motors. More studies evaluating further processing techniques for amorphous and nanocomposite materials are needed.

  15. Capture efficiency and injury rates of band-tailed pigeons using whoosh nets

    Science.gov (United States)

    Coxen, Christopher L.; Collins, Daniel P.; Carleton, Scott A.

    2018-01-01

    Catching ground feeding birds has typically been accomplished through small, walk-in funnel-style traps. This approach is limited because it requires a bird to find its way into the trap, is biased toward less wary birds, and does not allow targeted trapping of individual birds. As part of a large study on Band-tailed Pigeons (Patagioenas fasciata) in New Mexico, we needed a trapping method that would allow more control over the number of birds we could trap at one time, when a trap was deployed, and target trapping of specific individuals. We adopted a relatively novel trapping technique used primarily for shorebirds, whoosh nets, to trap Band-tailed Pigeons at 3 different sites where birds were being fed by local landowners. During 2013–2015, whoosh nets were used to trap 702 Band-tailed Pigeons at 3 different locations in New Mexico. We captured 12.54 ± 8.19 pigeons per shot over 56 capture events across 3 locations (range: 2–39). Some superficial injuries occurred using this technique and typically involved damage to the primary and secondary wing coverts. In 2013, 24% of captured birds had an injury of this nature, but after modifying the net speed, injury rates in 2014 and 2015 dropped to 8% and 7%, respectively. Recaptured previously injured birds showed new feather growth within 2 weeks and showed no signs of injury after 4 weeks. Whoosh nets proved to be a highly effective solution for trapping large numbers of pigeons at baited sites. These systems are easily transported, quickly deployed, and easily adapted to a variety of site conditions. 

  16. Efficiency improvement of variable speed electrical drives for HVAC applications

    Energy Technology Data Exchange (ETDEWEB)

    Abrahamsen, F.; Blaabjerg, F.; Pedersen, J.K. [Aalborg Univ., Inst. of Energy Technology, Aalborg East (Denmark)

    2000-07-01

    A large part of the produced electrical energy is consumed by ventilators, pumps and compressors, the so-called HVAC applications. A lot of this energy can be saved by speed control, but even with the large saving obtained alone by introduction of variable speed, it is still essential to optimise the control of the variable speed drive and to optimise the electrical machine with respect to efficiency. Experiments are made with energy optimal induction motor control on a 2.2 kW variable speed pump system. It is demonstrated that 10% of the consumed energy can typically be saved by energy optimal motor control compared with constant V/Hz control. In a comparison of induction motors and permanent magnet synchronous motors for a variable speed pump application it is shown that for 2.2 kW motors an investment in high-efficiency or PM motors are typically paid back within 2.5 years and 7 years respectively. For a 90 kW PM motor the pay-back time would be 24 years. It is today not profitable to use PM motors for variable speed HVAC applications above 2 kW rated motor power. A further study is required to determine this limit in power rating more precisely. (orig.)

  17. Net emissions of carbon dioxide to the atmosphere when using forest residues for production of heat and electricity

    International Nuclear Information System (INIS)

    Zetterberg, L.; Hansen, O.

    1998-05-01

    This study estimates net emissions of carbon dioxide to the atmosphere from the use of forest residues for production of heat and electricity. In the report, the use of forest residues for energy production is called residue-usage. Our results show that for a turnover period of 80 years, the net emission of CO 2 to the atmosphere is 15.8 kg CO 2 -C/MWh (3.1-31.6 kg CO 2 -C/MWh), which represents 16% of the total carbon content in the wood fuel (3%-32%). Fossil fuel consumption is responsible for 3.1 kg CO 2 -C/MWh of this. Residue-usage may produce indirect emissions or uptake of carbon dioxide, e.g. through changes in production conditions, changes in the turnover of carbon in the humus layer or through a reduction of the amount of forest fires. Due to uncertainties in data it is hard to quantify these indirect effects. In some cases it is hard even to determine their signs. As a consequence of this, we have chosen not to include the indirect effects in our estimates of net emissions from residue-usage. Instead we discuss these effects in a qualitative manner. It may seem surprising that the biogenic part of the residue-usage produces a net emission of carbon dioxide considering that carbon has originated from the atmosphere. The explanation is that the residue-usage systematically leads to earlier emissions than would be the case if the residues were left on the ground. If forest residues are left to decay, in the long run a pool of carbon might be created in the ground. This does not happen with residue-usage 33 refs, 4 figs, 12 tabs

  18. The economic effect of electricity net-metering with solar PV: Consequences for network cost recovery, cross subsidies and policy objectives

    International Nuclear Information System (INIS)

    Eid, Cherrelle; Reneses Guillén, Javier; Frías Marín, Pablo; Hakvoort, Rudi

    2014-01-01

    Net-metering is commonly known as a practice by which owners of distributed generation (DG) units may offset their electricity consumption from the grid with local generation. The increasing number of prosumers (consumers that both produce and consume electricity) with solar photovoltaic (PV) generation combined with net-metering results in reduced incomes for many network utilities worldwide. Consequently, this pushes utilities to increase charges per kW h in order to recover costs. For non-PV owners, this could result into inequality issues due to the fact that also non-PV owners have to pay higher chargers for their electricity consumed to make up for netted costs of PV-owners. In order to provide insight in those inequality issues caused by net-metering, this study presents the effects on cross-subsidies, cost recovery and policy objectives evolving from different applied netmetering and tariff designs for a residential consumer. Eventually this paper provides recommendations regarding tariffs and metering that will result in more explicit incentives for PV, instead of the current implicit incentives which are present to PV owners due to net-metering. - Highlights: • Network users are frequently charged by energy charging and fixed charging. • Net-metering with energy charging causes potential problems for DSO cost recovery. • Increasing rolling credit timeframes amplify net-metering impacts on cost recovery. • Observed capacity charging can incentivize local storage and self-consumption. • PV owners should receive direct incentives in order to avoid cross subsidization

  19. Impact of fuel-dependent electricity retail charges on the value of net-metered PV applications in vertically integrated systems

    International Nuclear Information System (INIS)

    Nikolaidis, Alexandros I.; Milidonis, Andreas; Charalambous, Charalambos A.

    2015-01-01

    Retail electricity charges inevitably influence the financial rationale of using net-metered photovoltaic (PV) applications since their structure as well as their level may vary significantly over the life-cycle of a customer-sited PV generation system. This subsequently introduces a further uncertainty for a ratepayer considering a net-metered PV investment. To thoroughly comprehend this uncertainty, the paper employs a top-down approach – in vertically integrated environments – to model the volatility of partially hedged electricity charges and its subsequent impact on the value of bill savings from net-metered PV systems. Besides the utility's pricing strategy and rate structures, particular emphasis is given in modeling the fossil fuel mix component that introduces a significant source of uncertainty on electricity charges and thus on the value of bill savings of net-metered, customer-sited, PV applications. - Highlights: • A top-down approach of developing traditional electricity charges is provided. • The combined effect of pricing strategies, rate structures and fuels is examined. • Fossil fuel prices can substantially affect the net metering compensation. • A financial risk assessment for net-metered PV systems is performed

  20. Gestió de factures electròniques amb .NET (Visual Studio Tools for Office)

    OpenAIRE

    Gimeno Capín, Pablo

    2008-01-01

    Creació d¿un software de gestió de factures electròniques desenvolupat en aquesta plataforma tecnològica, amb indicació expressa d¿utilització de les eines VSTO (Visual Studio Tools for Office) en la seva última versió. Creación de un software de gestión de facturas electrónicas desarrollado en esta plataforma tecnológica, con indicación expresa de utilización de las herramientas VSTO (Visual Studio Tools for Office) en su última versión. Creation of electronic invoice management softwa...

  1. Models for electricity market efficiency and bidding strategy analysis

    Science.gov (United States)

    Niu, Hui

    This dissertation studies models for the analysis of market efficiency and bidding behaviors of market participants in electricity markets. Simulation models are developed to estimate how transmission and operational constraints affect the competitive benchmark and market prices based on submitted bids. This research contributes to the literature in three aspects. First, transmission and operational constraints, which have been neglected in most empirical literature, are considered in the competitive benchmark estimation model. Second, the effects of operational and transmission constraints on market prices are estimated through two models based on the submitted bids of market participants. Third, these models are applied to analyze the efficiency of the Electric Reliability Council Of Texas (ERCOT) real-time energy market by simulating its operations for the time period from January 2002 to April 2003. The characteristics and available information for the ERCOT market are considered. In electricity markets, electric firms compete through both spot market bidding and bilateral contract trading. A linear asymmetric supply function equilibrium (SFE) model with transmission constraints is proposed in this dissertation to analyze the bidding strategies with forward contracts. The research contributes to the literature in several aspects. First, we combine forward contracts, transmission constraints, and multi-period strategy (an obligation for firms to bid consistently over an extended time horizon such as a day or an hour) into the linear asymmetric supply function equilibrium framework. As an ex-ante model, it can provide qualitative insights into firms' behaviors. Second, the bidding strategies related to Transmission Congestion Rights (TCRs) are discussed by interpreting TCRs as linear combination of forwards. Third, the model is a general one in the sense that there is no limitation on the number of firms and scale of the transmission network, which can have

  2. Differential efficiencies of dip-net sampling versus sampling surface-floating pupal exuviae in a biodiversity survey of Chironomidae

    Directory of Open Access Journals (Sweden)

    Leonard Charles Ferrington Jr

    2014-12-01

    Full Text Available Relative efficiencies of standard dip-net sampling (SDN versus collections of surface-floating pupal exuviae (SFPE were determined for detecting Chironomidae at catchment and site scales and at subfamily/tribe-, genus- and species-levels based on simultaneous, equal-effort sampling on a monthly basis for one year during a biodiversity assessment of Bear Run Nature Reserve. Results showed SFPE was more efficient than SDN at catchment scales for detecting both genera and species. At site scales, SDN sampling was more efficient for assessment of a first-order site. No consistent pattern, except for better efficiency of SFPE to detect Orthocladiinae genera, was observed at genus-level for two second-order sites. However, SFPE was consistently more efficient at detecting species of Orthocladiinae, Chironomini and Tanytarsini at the second order sites. SFPE was more efficient at detecting both genera and species at two third-order sites. The differential efficiencies of the two methods are concluded to be related to stream order and size, substrate size, flow and water velocity, depth and habitat heterogeneity, and differential ability to discriminate species among pupal exuviae specimens versus larval specimens. Although both approaches are considered necessary for comprehensive biodiversity assessments of Chironomidae, our results suggest that there is an optimal, but different, allocation of sampling effort for detecting Chironomidae across stream orders and at differing spatial and taxonomic scales.Article submitted 13. August 2014, accepted 31. October 2014, published 22. December 2014.

  3. Neural net based determination of generator-shedding requirements in electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Djukanovic, M [Electrical Engineering Inst. ' Nikola Tesla' , Belgrade (Yugoslavia); Sobajic, D J; Pao, Y -H [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Electrical Engineering and Applied Physics Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Computer Engineering and Science AI WARE Inc., Cleveland, OH (United States)

    1992-09-01

    This paper presents an application of artificial neural networks (ANN) in support of a decision-making process by power system operators directed towards the fast stabilisation of multi-machine systems. The proposed approach considers generator shedding as the most effective discrete supplementary control for improving the dynamic performance of faulted power systems and preventing instabilities. The sensitivity of the transient energy function (TEF) with respect to changes in the amount of dropped generation is used during the training phase of ANNs to assess the critical amount of generator shedding required to prevent the loss of synchronism. The learning capabilities of neural nets are used to establish complex mappings between fault information and the amount of generation to be shed, suggesting it as the control signal to the power system operator. (author)

  4. Energy-efficient microcontrollers for electric and hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Makowitz, Rainer; Gryska, Holger; Thanner, Manfred; Steinert, Frank [Freescale Halbleiter GmbH, Muenchen (Germany)

    2010-07-01

    Electric vehicles with their limited supply of energy are accelerating the trend towards more energy-efficient electronics that has started with the discussion on reducing the production of greenhouse gas of vehicles. While electricifaction of functions in a car is a technique that will help reduce overall energy consumption, microcontrollers are playing an important role in energetically optimizing the resulting electronics. In this presentation we give an overview of operating strategies for embedded automotive systems that lead to a set of power modes for the microcontrollers. Examples will be shown how Freescale's microcontrollers are designet to optimize energy consumption in each of these modes. We will also outline what needs to be done in the overall vehicle communication network design and in software to effectively use these new features of microcontrollers. The major elements that would benefit from standardization (e.g. in Autosar) will be indicated. (orig.)

  5. A model for efficient management of electrical assets

    International Nuclear Information System (INIS)

    Alonso Guerreiro, A.

    2008-01-01

    At the same time that energy demand grows faster than the investments in electrical installations, the older capacity is reaching the end of its useful life. The need of running all those capacity without interruptions and an efficient maintenance of its assets, are the two current key points for power generation, transmission and distribution systems. This paper tries to show the reader a model of management which makes possible an effective management of assets with a strict control cost, and which includes those key points, centred at predictive techniques, involving all the departments of the organization and which goes further on considering the maintenance like a simple reparation or substitution of broken down units. Therefore, it becomes precise a model with three basic lines: supply guarantee, quality service and competitively, in order to allow the companies to reach the current demands which characterize the power supply. (Author) 5 refs

  6. Net fossil energy savings for alternative mixes in various electric supply systems

    International Nuclear Information System (INIS)

    Essam, P.; Stocks, K.J.

    1978-11-01

    The actual and projected electric power station building programs of several countries and regions have been examined to determine what effect the introduction of nuclear power has on fossil fuel usage by the electricity system. It was found that (1) nuclear power leads directly to savings in fossil fuel usage, a larger nuclear component leading to larger savings; (2) individual nuclear stations rapidly wipe out the energy 'debt' incurred during building; and (3) the relatively short periods of consolidation in the early stages of a nation's building program usually prevent the nuclear component from going into energy 'debt'. Assessments of the energy requirements to build and run various types of power station have been made from the available literature

  7. Uncertainties in the Value of Bill Savings from Behind-the-Meter, Residential Photovoltaic Systems: The Roles of Electricity Market Conditions, Retail Rate Design, and Net Metering

    OpenAIRE

    Darghouth, Naim Richard

    2013-01-01

    Net metering has become a widespread policy mechanism in the U.S. for supporting customer adoption of distributed photovoltaics (PV), allowing customers with PV systems to reduce their electric bills by offsetting their consumption with PV generation, independent of the timing of the generation relative to consumption. Although net metering is one of the principal drivers for the residential PV market in the U.S., the academic literature on this policy has been sparse and this dissertation co...

  8. Intercalibration of MOCNESS and Bongo nets: Assessing relative efficiency for ichthyoplankton

    Science.gov (United States)

    Johnson, Donna L.; Fogarty, Michael J.

    2013-01-01

    The evaluation of catchability of egg and larval fish with the 0.61-m Bongo and the 1-m2 Multiple Opening and Closing Net Environmental Sensing System (MOCNESS) was conducted as part of a paired station analysis. The two samplers were deployed on 331 stations on Georges Bank during the U.S. GLOBEC program from January through June for years 1996 and 1997. Significant differences were found when combined catches of all eggs and all larvae for each sampler were compared. Overall catches of larvae from the MOCNESS were 3-5 times greater than those from the Bongo. Gear effects were modeled and revealed that the catches in 14 of the 22 dominant taxa were significantly different between sampling gear. The differences between samplers during diel intervals for the taxa were not significantly different.

  9. Approaches to Electric Utility Energy Efficiency for Low Income Customers in a Changing Regulatory Environment

    Energy Technology Data Exchange (ETDEWEB)

    Brockway, N.

    2001-05-21

    As the electric industry goes through a transformation to a more market-driven model, traditional grounds for utility energy efficiency have come under fire, undermining the existing mechanisms to fund and deliver such services. The challenge, then, is to understand why the electric industry should sustain investments in helping low-income Americans use electricity efficiently, how such investments should be made, and how these policies can become part of the new electric industry structure. This report analyzes the opportunities and barriers to leveraging electric utility energy efficiency assistance to low-income customers during the transition of the electric industry to greater competition.

  10. Research on High-efficient Remanufacturing Technologies and Application of Electric Motor

    Science.gov (United States)

    Liu, Ren; Zhao, Yuejin; Yang, Xu; Wang, Gen

    2017-09-01

    The energy conservation of electric motor system is the key of industrial energy conservation. With the implementation and acceleration of electric motor energy efficiency improvement plan, more and more electric motors are knocked out. High-efficient remanufacturing of electric motor refers to improving the efficiency of electric motor and recycling the resources by replacing the winding, iron core and other components of electric motor on the basis of the low-efficient/outdated electric motors, which conforms to China’s policy of circular economy and resource recovery. The remanufacturing of electric motor not only maximizes the use of resources, but also reduces the energy consumption generated by reprocessing of cast iron, silicon steel sheet and other materials in dismantling of electric motor. However, structures and iron core materials used in design and manufacture of electric motors are different, and the degrees of wear of electric motors are also different under different operating conditions, which further result in diversified design schemes, increased remanufacturing cost and reduced remanufacturing efficiency. This paper analyzes the key process technologies for remanufacturing of electric motors are researched by analyzing the remanufacturing technologies of electric motors, and presents the feasibility to replace the cast-aluminum rotor with cast-copper rotor in high-efficient remanufacturing process of electric motor.

  11. Efficient Transfer of Graphene-Physical and Electrical Performance Perspective

    KAUST Repository

    Ghoneim, Mohamed T.

    2012-11-01

    Efficient Transfer of Graphene –Physical and Electrical Performance Perspective Graphene has become one of the most widely used atomic crystal structure materials since its first experimental proof by Geim-Novoselov in 2004 [1]. This is attributed to its reported incredible carrier mobility, mechanical strength and thermal conductivity [2] [3] [4]. These properties suggest interesting applications of Graphene ranging from electronics to energy storage and conversion [5]. In 2008, Chen et al reported a 40,000 cm2V-1s-1 mobility for a Single Layer Graphene (SLG) on SiO2 compared to 285 cm2V-1s-1 for silicon channel devices [6]. Chemical vapor deposition (CVD) is a common method for growing graphene on a metal surface as a catalyst for graphene nucleation. This adds a necessary transfer step to the target substrate ultimately desired for graphene devices fabrication. Interfacing with graphene is a critical challenge in preserving its promising high mobility. This initiated the motivation for studying the effect of intermediate interfaces imposed by transfer processes. In this work, few layers graphene (FLG) was grown on copper foils inside a high temperature furnace. Then Raman spectroscopy was performed on grown graphene sample to confirm few (in between 3-10) layers. Afterwards the sample was cut into three pieces and transferred to 300 nm SiO2 on Si substrates using three techniques, namely: (i) pickup transfer with top side of Graphene brought in contact with SiO2 [7], (ii) Ploy (methyl methacrylate) (PMMA) transfer with Graphene and a PMMA support layer on top scooped from bottom side [8], and (iii) a modified direct transfer which is similar to PMMA transfer without the support layer [9]. Comparisons were done using Raman spectroscopy to determine the relative defectivity, Scanning Electron Microscopy (SEM) to observe discontinuities and Atomic Force Microscopy (AFM) to measure surface roughness. Then we conclude with electrical data based on the contact

  12. Efficient ConvNet Feature Extraction with Multiple RoI Pooling for Landmark-Based Visual Localization of Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    Yi Hou

    2017-01-01

    Full Text Available Efficient and robust visual localization is important for autonomous vehicles. By achieving impressive localization accuracy under conditions of significant changes, ConvNet landmark-based approach has attracted the attention of people in several research communities including autonomous vehicles. Such an approach relies heavily on the outstanding discrimination power of ConvNet features to match detected landmarks between images. However, a major challenge of this approach is how to extract discriminative ConvNet features efficiently. To address this challenging, inspired by the high efficiency of the region of interest (RoI pooling layer, we propose a Multiple RoI (MRoI pooling technique, an enhancement of RoI, and a simple yet efficient ConvNet feature extraction method. Our idea is to leverage MRoI pooling to exploit multilevel and multiresolution information from multiple convolutional layers and then fuse them to improve the discrimination capacity of the final ConvNet features. The main advantages of our method are (a high computational efficiency for real-time applications; (b GPU memory efficiency for mobile applications; and (c use of pretrained model without fine-tuning or retraining for easy implementation. Experimental results on four datasets have demonstrated not only the above advantages but also the high discriminating power of the extracted ConvNet features with state-of-the-art localization accuracy.

  13. Assessment of Export Efficiency Equations in the Southern Ocean Applied to Satellite-Based Net Primary Production

    Science.gov (United States)

    Arteaga, Lionel; Haëntjens, Nils; Boss, Emmanuel; Johnson, Kenneth S.; Sarmiento, Jorge L.

    2018-04-01

    Carbon export efficiency (e-ratio) is defined as the fraction of organic carbon fixed through net primary production (NPP) that is exported out of the surface productive layer of the ocean. Recent observations for the Southern Ocean suggest a negative e-ratio versus NPP relationship, and a reduced dependency of export efficiency on temperature, different than in the global domain. In this study, we complement information from a passive satellite sensor with novel space-based lidar observations of ocean particulate backscattering to infer NPP over the entire annual cycle, and estimate Southern Ocean export rates from five different empirical models of export efficiency. Inferred Southern Ocean NPP falls within the range of previous studies, with a mean estimate of 15.8 (± 3.9) Pg C yr-1 for the region south of 30°S during the 2005-2016 period. We find that an export efficiency model that accounts for silica(Si)-ballasting, which is constrained by observations with a negative e-ratio versus NPP relationship, shows the best agreement with in situ-based estimates of annual net community production (annual export of 2.7 ± 0.6 Pg C yr-1 south of 30°S). By contrast, models based on the analysis of global observations with a positive e-ratio versus NPP relationship predict annually integrated export rates that are ˜ 33% higher than the Si-dependent model. Our results suggest that accounting for Si-induced ballasting is important for the estimation of carbon export in the Southern Ocean.

  14. Energy-efficient electrical machines by new materials. Superconductivity in large electrical machines

    International Nuclear Information System (INIS)

    Frauenhofer, Joachim; Arndt, Tabea; Grundmann, Joern

    2013-01-01

    The implementation of superconducting materials in high-power electrical machines results in significant advantages regarding efficiency, size and dynamic behavior when compared to conventional machines. The application of HTS (high-temperature superconductors) in electrical machines allows significantly higher power densities to be achieved for synchronous machines. In order to gain experience with the new technology, Siemens carried out a series of development projects. A 400 kW model motor for the verification of a concept for the new technology was followed by a 4000 kV A generator as highspeed machine - as well as a low-speed 4000 kW propeller motor with high torque. The 4000 kVA generator is still employed to carry out long-term tests and to check components. Superconducting machines have significantly lower weight and envelope dimensions compared to conventional machines, and for this reason alone, they utilize resources better. At the same time, operating losses are slashed to about half and the efficiency increases. Beyond this, they set themselves apart as a result of their special features in operation, such as high overload capability, stiff alternating load behavior and low noise. HTS machines provide significant advantages where the reduction of footprint, weight and losses or the improved dynamic behavior results in significant improvements of the overall system. Propeller motors and generators,for ships, offshore plants, in wind turbine and hydroelectric plants and in large power stations are just some examples. HTS machines can therefore play a significant role when it comes to efficiently using resources and energy as well as reducing the CO 2 emissions.

  15. Uncertainties in the Value of Bill Savings from Behind-the-Meter, Residential Photovoltaic Systems: The Roles of Electricity Market Conditions, Retail Rate Design, and Net Metering

    Science.gov (United States)

    Darghouth, Naim Richard

    Net metering has become a widespread policy mechanism in the U.S. for supporting customer adoption of distributed photovoltaics (PV), allowing customers with PV systems to reduce their electric bills by offsetting their consumption with PV generation, independent of the timing of the generation relative to consumption. Although net metering is one of the principal drivers for the residential PV market in the U.S., the academic literature on this policy has been sparse and this dissertation contributes to this emerging body of literature. This dissertation explores the linkages between the availability of net metering, wholesale electricity market conditions, retail rates, and the residential bill savings from behind-the-meter PV systems. First, I examine the value of the bill savings that customers receive under net metering and alternatives to net metering, and the associated role of retail rate design, based on current rates and a sample of approximately two hundred residential customers of California's two largest electric utilities. I find that the bill savings per kWh of PV electricity generated varies greatly, largely attributable to the increasing block structure of the California utilities' residential retail rates. I also find that net metering provides significantly greater bill savings than alternative compensation mechanisms based on avoided costs. However, retail electricity rates may shift as wholesale electricity market conditions change. I then investigate a potential change in market conditions -- increased solar PV penetrations -- on wholesale prices in the short-term based on the merit-order effect. This demonstrates the potential price effects of changes in market conditions, but also points to a number of methodological shortcomings of this method, motivating my usage of a long-term capacity investment and economic dispatch model to examine wholesale price effects of various wholesale market scenarios in the subsequent analysis. By developing

  16. A Controlled Design of Ripple-Like Polyamide-6 Nanofiber/Nets Membrane for High-Efficiency Air Filter.

    Science.gov (United States)

    Zhang, Shichao; Liu, Hui; Zuo, Fenglei; Yin, Xia; Yu, Jianyong; Ding, Bin

    2017-03-01

    The filtration capacity of fibrous media for airborne particles is restricted by their thick diameter, low porosity, and limited frontal area. The ability to solve this problem would have broad technological implications for various air filtration applications; despite many past efforts, it remains a great challenge to achieve. Herein, a facile and scalable strategy to fabricate the ripple-like polyamide-6 nanofiber/nets (PA-6 NF/N) air filter via combining electrospinning/netting technique with receiving substrate design is demonstrated. This proposed approach allows the scaffold filaments to orderly embed into 2D PA-6 nanonets layer with Steiner-tree structures and nanoscale diameter of ≈20 nm, resulting in the ripple-like membrane with extremely small pore size, highly porous structure, and hugely extended frontal surface, by facilely adjusting its pleat span and pleat pitch. These unique structural advantages enable the ripple-like PA-6 NF/N filter to filtrate the ultrafine particles with high removal efficiency of 99.996%, low air resistance of 95 Pa, and robust quality factor of >0.11 Pa -1 ; using its superlight weight of 0.9 g m -2 and physical sieving manner. This approach has the potentialities to give rise to a novel generation of filter media displaying enhanced filtration capacity for various applications thanks to their nanoscale features and designed macrostructures. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Hybrid and Plug-In Electric Vehicles (Spanish Version); Clean Cities, Energy Efficiency & Renewable Energy (EERE)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-08-01

    This is a Spanish-language brochure about hybrid and plug-in electric vehicles, which use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), all-electric vehicles (EVs). Together, they have great potential to cut U.S. petroleum use and vehicle emissions.

  18. Restructuring, ownership and efficiency in the electricity industry

    Science.gov (United States)

    Shanefelter, Jennifer Kaiser

    The first chapter considers improvements in productive efficiency that can result from a movement from a regulated framework to one that allows for market-based incentives for industry participants. Specifically, I look at the case of restructuring in the electricity generation industry. Using data from the electricity industry, this analysis considers the total effect of restructuring on one input to the production process, labor, as reflected in employment levels, payroll per employee and aggregate establishment payroll. Using concurrent payroll and employment data from non-utility ("merchant") and utility generators in both restructured and nonrestructured states, I estimate the effect of market liberalization, comprising both new entry and state-level legislation, on employment and payroll in this industry. I find that merchant owners of divested generation assets employ significantly fewer people, but that the payroll per employee is not significantly different from what workers at utility-owned plants are paid. As a result, the new merchant owners of these plants have significantly lower aggregate payroll expenses. Decomposing the effect into a merchant effect and a divestiture effect, I find that merchant ownership is the primary driver of these results. As documented in Chapter 1, merchant power plants have lower overall payroll costs than plants owned by utilities. Employment at merchant power plants is characterized by reduced staffing levels but higher average payroll per employee. A hypothesis set forth in that paper is that merchant generators employ fewer workers at the lower end of the wage distribution, resulting in a higher average payroll per employee. The second chapter of this paper examines whether employment at nonutility power plants, that is, those that are either divested or native merchant power plants, is skewed towards more skilled labor. This chapter also considers the extent to which the difference in employment levels is the result of

  19. Correction: Towards the rationalization of catalytic activity values by means of local hyper-softness on the catalytic site: a criticism about the use of net electric charges.

    Science.gov (United States)

    Martínez-Araya, Jorge Ignacio; Grand, André; Glossman-Mitnik, Daniel

    2016-01-28

    Correction for 'Towards the rationalization of catalytic activity values by means of local hyper-softness on the catalytic site: a criticism about the use of net electric charges' by Jorge Ignacio Martínez-Araya et al., Phys. Chem. Chem. Phys., 2015, DOI: 10.1039/c5cp03822g.

  20. Algorithms for computing efficient, electric-propulsion, spiralling trajectories

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop techniques for rapidly designing many-revolution, electric-propulsion, spiralling trajectories, including the effects of shadowing, gravity harmonics, and...

  1. Energy indicators for electricity production : comparing technologies and the nature of the indicators Energy Payback Ratio (EPR), Net Energy Ratio (NER) and Cumulative Energy Demand (CED). [Oestfoldforskning AS

    Energy Technology Data Exchange (ETDEWEB)

    Raadal, Hanne Lerche [Ostfold research, Fredrikstad (Norway); Modahl, Ingunn Saur [Ostfold research, Fredrikstad (Norway); Bakken, Tor Haakon [SINTEF Energy, Trondheim (Norway)

    2012-11-01

    CEDREN (Centre for Environmental Design of Renewable Energy) is founded by The Research Council of Norway and energy companies and is one of eight centres that were part of the scheme Centre for Environment-friendly Energy Research (FME) when the scheme was launched in 2009. The main objective of CEDREN is to develop and communicate design solutions for transforming renewable energy sources to the desired energy products, and at the same time address the environmental and societal challenges at local, regional, national and global levels. CEDREN's board initiated in 2011 a pilot project on the topics 'Energy Pay-back Ratio (EPR)', 'Ecosystem services' and 'multi-criteria analysis (MCA)' in order to investigate the possible use of these concepts/indices in the management of regulated river basins and as tools to benchmark strategies for the development of energy projects/resources. The energy indicator part (documented in this report) has aimed at reviewing the applicability of different energy efficiency indicators, as such, in the strategic management and development of energy resources, and to compare and benchmark technologies for production of electricity. The main findings from this pilot study is also reported in a policy memo (in Norwegian), that is available at www.cedren.no. The work carried out in this project will be continued in the succeeding research project EcoManage, which was granted by the Research Council of Norway's RENERGI programme in December 2011. Energy indicators: Several energy indicators for extraction and delivery of an energy product (e.g. transport fuel, heat, electricity etc.) exist today. The main objective of such indicators is to give information about the energy efficiency of the needed extraction and transforming processes throughout the value chain related to the delivered energy product. In this project the indicators Energy Payback Ratio (EPR), Net Energy Ration (NER) and Cumulative

  2. Energy efficient selective reforming of hydrocarbons. ERA-NET Bioenergy. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rodin, J.

    2010-07-15

    The research project 'Energy efficient selective reforming of hydrocarbons', funded by the Swedish and Energinet.dk Agency has now reached its end. The report is an overview of the work. Details of the work within the different areas can be found in the reports from each part. In this project, an innovative method for tar removal and reformation of hydrocarbons was investigated: Chemical Looping Reforming (CLR). This gas treatment has the potential to be economically competitive, reliable and environmentally friendly (due to higher energy efficiency, amongst others). The aim of the CLR is to 1) eliminate downstream problems with tar 2) simplify the energy recovery from the hot product gas 3) selectively save lighter hydrocarbons for the production of synthetic natural gas (SNG). A guarantor for the outcome of the project is the engagement of Goeteborg Energi, which has a commitment to build a 20 MW output SNG plant by 2012. DTU (Danish Technical University) is responsible for carrying out the laboratorial part, where different oxygen carriers for the CLR have been considering their capability of selectively reforming hydrocarbons. The conclusion was that, of the four carriers tested, the Mn and Ni40 was the most promising. CUT (Chalmers University of Technology) has installed a 600 W CLR unit connected to a slipstream from the gasifier. During the firing season 2010 the CLR has been tested with raw gas for 36 hours and the results so far show that the equipment works as intended and that it can reduce the amount of tars substantially. GE (Goeteborg Energi AB) together with SEP (Scandinavian Energy Project AB) and CUT have studied the integration of a methane production plant to an existing boiler. The main focus of the study has been the gasifier and the CLR. The integration of a 100 MW methane production plant is estimated to cost 1.3-2.4 billion SEK. The different work packages have altogether shown that a CLR is a possible solution to the tar problem

  3. Influence of cable losses on the economic analysis of efficient and sustainable electrical equipment

    International Nuclear Information System (INIS)

    Lobão, J.A.; Devezas, T.; Catalão, J.P.S.

    2014-01-01

    Increasing energy needs are accompanied by environmental responsibilities, since nowadays electricity companies operate in a competitive and sustainable energy framework. In this context, any proposal for action on energy efficiency becomes important for consumers to minimize operational costs. In electrical installations, electricity consumption can be decreased by reducing losses in the cables, associated with the overall efficiency of the equipment, allowing a better use of the installed power. The losses must be analysed in conjunction with all loads that contribute to the currents in the sections of an electrical installation. When replacing equipment in output distribution boxes with more efficient ones, the current in those sections is reduced in association with the decrease in power losses. This decrease, often forgotten, is taken into account in this work for the economic analysis of efficiency and sustainable electrical equipment. This paper presents a new software application that compares and chooses the best investment in the acquisition of electrical equipment. Simulation results obtained with the new software application are provided and are then validated with experimental results from a real electrical installation. - Highlights: • Any proposal for action on energy efficiency is important for consumers. • Electricity consumption can be decreased by reducing losses in the cables. • A new software application that compares and chooses the best investment is provided. • The economic analysis of efficiency and sustainable electrical equipment is carried out. • Simulation results are validated with experimental results from a real electrical installation

  4. A framework for establishing the technical efficiency of Electricity Distribution Counties (EDCs) using Data Envelopment Analysis

    International Nuclear Information System (INIS)

    Mullarkey, Shane; Caulfield, Brian; McCormack, Sarah; Basu, Biswajit

    2015-01-01

    Highlights: • Six models are employed to establish the technical efficiency of Electricity Distribution Counties. • A diagnostic parameter is incorporated to account for differences across Electricity Distribution Counties. • The amalgamation of Electricity Distribution Counties leads to improved efficiency in the production of energy. - Abstract: European Energy market liberalization has entailed the restructuring of electricity power markets through the unbundling of electricity generation, transmission and distribution, supply activities and introducing competition into electricity generation. Under these new electricity market regimes, it is important to have an evaluation tool that is capable of examining the impacts of these market changes. The adoption of Data Envelopment Analysis as a form of benchmarking for electricity distribution regulation is one method to conduct this analysis. This paper applies a Data Envelopment Analysis framework to the electricity distribution network in Ireland to explore the merits of using this approach, to determine the technical efficiency and the potential scope for efficiency improvements through reorganizing and the amalgamation of the distribution network in Ireland. The results presented show that overall grid efficiency is improved through this restructuring. A diagnostic parameter is defined and pursued to account for aberrations across Electricity Distribution Counties as opposed to the traditionally employed environmental variables. The adoption of this diagnostic parameter leads to a more intuitive understanding of Electricity Distribution Counties

  5. Seven proposals for an efficient and dynamic European electricity system

    International Nuclear Information System (INIS)

    Keppler, J.H.; Geoffon, P.; Finon, D.

    2013-01-01

    While liberalisation of the electricity generation sector is inevitably a long term process, given the complexity of the industry, European consumers expect to reap identifiable benefits in terms of price, innovation in associated services, environmental performance and security of supply. Yet rather than evidence of progress, complexity - indeed confusion - effectively characterises Europe's electricity structure at present. It's time to react. (authors)

  6. Seven proposals for an efficient and dynamic European electricity system

    International Nuclear Information System (INIS)

    Keppler, Jan Horst; Geoffron, Patrice; Finon, Dominique

    2013-01-01

    While liberalisation of the electricity generation sector is inevitably a long term process, given the complexity of the industry, European consumers expect to reap identifiable benefits in terms of price, innovation in associated services, environmental performance and security of supply. Yet rather than evidence of progress, complexity - indeed confusion - effectively characterises Europe's electricity structure at present. It is time to react

  7. More efficiency due to the liberalization of the market for electricity

    International Nuclear Information System (INIS)

    Huisman, R.; Huurman, C.I.

    2004-01-01

    The market for electricity in the Netherlands has become more efficient due to the liberalization. This can be deducted from the fact that prices at the so-called imbalance market have risen. Producers of electricity are stimulated to better estimate the demand for electricity [nl

  8. Efficient electricity storage with a battolyser, an integrated Ni-Fe battery and electrolyser

    NARCIS (Netherlands)

    Mulder, F.M.; Weninger, B.; Middelkoop, J.; Ooms, F.G.B.; Schreuders, H.

    2017-01-01

    Grid scale electricity storage on daily and seasonal time scales is required to accommodate increasing amounts of renewable electricity from wind and solar power. We have developed for the first time an integrated battery-electrolyser ('battolyser') that efficiently stores electricity as a

  9. Loss minimization control and efficiency determination of electric drives in traction applications

    Energy Technology Data Exchange (ETDEWEB)

    Windisch, Thomas; Hofmann, Wilfried [Technische Univ. Dresden (Germany). Lehrstuhl fuer Elektrische Maschinen und Antriebe

    2012-11-01

    High-power electric drives in automotive traction applications consume a large part of the disposable electric energy. For this reason the energy efficiency of the drives is of great importance for range and fuel consumption of the hybrid electric vehicle. The paper describes two possible drives with different electric motors from a control point of view. The electric power losses in the drive system are determined depending on the operating point of the machine. With these loss characteristics the control of the drives is optimized to produce minimal losses. Finally the energy efficiency for a realistic urban bus drive cycle is calculated to compare the two types. (orig.)

  10. The role of efficiency estimates in regulatory price reviews: Ofgem's approach to benchmarking electricity networks

    International Nuclear Information System (INIS)

    Pollitt, Michael

    2005-01-01

    Electricity regulators around the world make use of efficiency analysis (or benchmarking) to produce estimates of the likely amount of cost reduction which regulated electric utilities can achieve. This short paper examines the use of such efficiency estimates by the UK electricity regulator (Ofgem) within electricity distribution and transmission price reviews. It highlights the place of efficiency analysis within the calculation of X factors. We suggest a number of problems with the current approach and make suggestions for the future development of X factor setting. (author)

  11. Contributing to Net Zero Building: High Energy Efficient EIFS Wall Systems

    Energy Technology Data Exchange (ETDEWEB)

    Carbary, Lawrence D. [Dow Corning Corporation; Perkins, Laura L. [Dow Corning Corporation; Serino, Roland [Dryvit Systems, Inc; Preston, Bill [Dryvit Systems, Inc; Kosny, Jan [Fraunhofer USA, Inc. CSE

    2014-01-29

    The team led by Dow Corning collaborated to increase the thermal performance of exterior insulation and finishing systems (EIFS) to reach R-40 performance meeting the needs for high efficiency insulated walls. Additionally, the project helped remove barriers to using EIFS on retrofit commercial buildings desiring high insulated walls. The three wall systems developed within the scope of this project provide the thermal performance of R-24 to R-40 by incorporating vacuum insulation panels (VIPs) into an expanded polystyrene (EPS) encapsulated vacuum insulated sandwich element (VISE). The VISE was incorporated into an EIFS as pre-engineered insulation boards. The VISE is installed using typical EIFS details and network of trained installers. These three wall systems were tested and engineered to be fully code compliant as an EIFS and meet all of the International Building Code structural, durability and fire test requirements for a code compliant exterior wall cladding system. This system is being commercialized under the trade name Dryvit® Outsulation® HE system. Full details, specifications, and application guidelines have been developed for the system. The system has been modeled both thermally and hygrothermally to predict condensation potential. Based on weather models for Baltimore, MD; Boston, MA; Miami, FL; Minneapolis, MN; Phoenix, AZ; and Seattle, WA; condensation and water build up in the wall system is not a concern. Finally, the team conducted a field trial of the system on a building at the former Brunswick Naval Air Station which is being redeveloped by the Midcoast Regional Redevelopment Authority (Brunswick, Maine). The field trial provided a retrofit R-30 wall onto a wood frame construction, slab on grade, 1800 ft2 building, that was monitored over the course of a year. Simultaneous with the façade retrofit, the building’s windows were upgraded at no charge to this program. The retrofit building used 49% less natural gas during the winter of

  12. The Efficiency Improvement by Combining HHO Gas, Coal and Oil in Boiler for Electricity Generation

    Directory of Open Access Journals (Sweden)

    Chia-Nan Wang

    2017-02-01

    Full Text Available Electricity is an essential energy that can benefit our daily lives. There are many sources available for electricity generation, such as coal, natural gas and nuclear. Among these sources, coal has been widely used in thermal power plants that account for about 41% of the worldwide electricity supply. However, these thermal power plants are also found to be a big pollution source to our environment. There is a need to explore alternative electricity sources and improve the efficiency of electricity generation. This research focuses on improving the efficiency of electricity generation through the use of hydrogen and oxygen mixture (HHO gas. In this research, experiments have been conducted to investigate the combined effects of HHO gas with other fuels, including coal and oil. The results show that the combinations of HHO with coal and oil can improve the efficiency of electricity generation while reducing the pollution to our environment.

  13. Variable cross-section windings for efficiency improvement of electric machines

    Science.gov (United States)

    Grachev, P. Yu; Bazarov, A. A.; Tabachinskiy, A. S.

    2018-02-01

    Implementation of energy-saving technologies in industry is impossible without efficiency improvement of electric machines. The article considers the ways of efficiency improvement and mass and dimensions reduction of electric machines with electronic control. Features of compact winding design for stators and armatures are described. Influence of compact winding on thermal and electrical process is given. Finite element method was used in computer simulation.

  14. The efficient future of deep-space travel - electric rockets; Das Zeitalter der Elektrischen Raketen

    Energy Technology Data Exchange (ETDEWEB)

    Choueiri, Edgar Y. [Princeton Univ., NJ (United States). Electric Propulsion and Plasma Dynamics Lab.

    2010-01-15

    Conventional rockets generate thrust by burning chemical fuel. Electric rockets propel space vehicles by applying electric or electromagnetic fields to clouds of charged particles, or plasmas, to accelerate them. Although electric rockets offer much lower thrust levels than their chemical cousins, they can eventually enable spacecraft to reach greater speeds for the same amount of propellant. Electric rockets' high-speed capabilities and their efficient use of propellant make them valuable for deep-space missions. (orig.)

  15. The Efficiency Improvement by Combining HHO Gas, Coal and Oil in Boiler for Electricity Generation

    OpenAIRE

    Chia-Nan Wang; Min-Tsong Chou; Hsien-Pin Hsu; Jing-Wein Wang; Sridhar Selvaraj

    2017-01-01

    Electricity is an essential energy that can benefit our daily lives. There are many sources available for electricity generation, such as coal, natural gas and nuclear. Among these sources, coal has been widely used in thermal power plants that account for about 41% of the worldwide electricity supply. However, these thermal power plants are also found to be a big pollution source to our environment. There is a need to explore alternative electricity sources and improve the efficiency of elec...

  16. Climate impact and energy efficiency from electricity generation through anaerobic digestion or direct combustion of short rotation coppice willow

    International Nuclear Information System (INIS)

    Ericsson, Niclas; Nordberg, Åke; Sundberg, Cecilia; Ahlgren, Serina; Hansson, Per-Anders

    2014-01-01

    Highlights: • Using LCA, CHP from willow use in biogas was compared with direct combustion. • Direct combustion was ninefold more energy-efficient. • Biogas had a much greater cooling effect on global mean surface temperature. • The effects of soil carbon changes on temperature over time differed. • Biogas had long-term temperature effects, direct combustion short-term effects. - Abstract: Short rotation coppice willow is an energy crop used in Sweden to produce electricity and heat in combined heat and power plants. Recent laboratory-scale experiments have shown that SRC willow can also be used for biogas production in anaerobic digestion processes. Here, life cycle assessment is used to compare the climate impact and energy efficiency of electricity and heat generated by these measures. All energy inputs and greenhouse gas emissions, including soil organic carbon fluxes were included in the life cycle assessment. The climate impact was determined using time-dependent life cycle assessment methodology. Both systems showed a positive net energy balance, but the direct combustion system delivered ninefold more energy than the biogas system. Both systems had a cooling effect on the global mean surface temperature change. The cooling impact per hectare from the biogas system was ninefold higher due to the carbon returned to soil with the digestate. Compensating the lower energy production of the biogas system with external energy sources had a large impact on the result, effectively determining whether the biogas scenario had a net warming or cooling contribution to the global mean temperature change per kWh of electricity. In all cases, the contribution to global warming was lowered by the inclusion of willow in the energy system. The use of time-dependent climate impact methodology shows that extended use of short rotation coppice willow can contribute to counteract global warming

  17. ENERGY EFFICIENCY DETERMINATION OF LOADING-BACK SYSTEM OF ELECTRIC TRACTION MACHINES

    Directory of Open Access Journals (Sweden)

    A. M. Afanasov

    2014-03-01

    Full Text Available Purpose.Acceptance post-repair testsof electric traction machinesare conducted onloading-backstandsthat reducethe overall power costsfor the tests.Currentlya numberof possiblecircuit designs of loading-backsystems of electric machines are known, but there is nomethod of determiningtheir energy efficiency. This in turn makes difficult the choiceof rationaloptions. The purpose of the article is the development of the corresponding methodo-logy to make easier this process. Methodology. Expressions for determining theenergy efficiency ofa stand for testingof electric traction machineswere obtained using the generalizedscheme analysisof energy transformationsin the loading-backsystems of universal structure. Findings.Thetechnique wasoffered and the analytical expressions for determining the energy efficiency of loading-backsystemsof electric traction machines wereobtained. Energy efficiency coefficientofloading-backsystemisproposed to consider as the ratio of the total actionenergy of the mechanical and electromotive forces, providing anchors rotation and flowof currents in electric machines, which are being tested,to the total energy, consumed during the test from the external network. Originality. The concept was introduced and the analytical determination method of the energy efficiency of loading-backsystem in electric traction machines was offered. It differs by efficiency availability of power sources and converters, as well as energy efficiency factors of indirect methods of loss compensation. Practical value. The proposed technique of energy efficiency estimation of a loading-backsystemcan be used in solving the problem of rational options choice of schematics stands decisions for electric traction machines acceptance tests of main line and industrial transport.

  18. A brief report on the statistical study of net electric current in solar active regions with longitudinal fields of opposite polarity

    International Nuclear Information System (INIS)

    Gao Yu

    2013-01-01

    Dynamic processes occurring in solar active regions are dominated by the solar magnetic field. As of now, observations using a solar magnetograph have supplied us with the vector components of a solar photospheric magnetic field. The two transverse components of a photospheric magnetic field allow us to compute the amount of electric current. We found that the electric current in areas with positive (negative) polarity due to the longitudinal magnetic field have both positive and negative signs in an active region, however, the net current is found to be an order-of-magnitude less than the mean absolute magnitude and has a preferred sign. In particular, we have statistically found that there is a systematic net electric current from areas with negative (positive) polarity to areas with positive (negative) polarity in solar active regions in the northern (southern) hemisphere, but during the solar minimum this tendency is reversed over time at some latitudes. The result indicates that there is weak net electric current in areas of solar active regions with opposite polarity, thus providing further details about the hemispheric helicity rule found in a series of previous studies.

  19. Improving electricity efficiency in Turkey by addressing illegal electricity consumption: A governance approach

    International Nuclear Information System (INIS)

    Tasdoven, Hidayet; Fiedler, Beth Ann; Garayev, Vener

    2012-01-01

    Recent reform activities to liberate and privatize the Turkish utility energy sector through deregulation have transformed the scope of the historically government-owned corporations. However, during the free market process approach, power theft has become an issue that requires national attention. This paper examines the current use of two governance tools—privatization and regulation, and suggests two others to promote a framework of efficient electricity distribution (grants and public information). The capacity of the tools to provide a solution to power losses is discussed while considering the barrier of political acceptability in regions of the country where pockets of resistance exist. - Highlights: ► Energy sector reforms in Turkey have transformed scope of the government-owned corporations. ► Power theft has become an essential issue in this liberalization process. ► In addition to currently used two governance tools, two others are suggested to be used. ► The tools are promising to address the power theft issue as long as they are politically acceptable.

  20. Comparative analysis of efficiency in cooking with natural gas and electricity

    International Nuclear Information System (INIS)

    Amell Arrieta, Andres; Cadavid Sierra Francisco Javier; Ospina Ospina, Juan Carlos

    2001-01-01

    The natural gas will have, at the Aburra Valley, a massive application in residential process like heating water and cooking, historically doing with electricity. In the study of electricity substitution in necessary to estimate the gas consumption in order to keep satisfying the energetic requirements at the different strata supposing that, alimentary habits in these have not important valuation through the time. Since the volume of natural gas requirements for the electricity substitution at given conditions depend on electrical energy before substitution, electrical equipment efficiency, gas equipment efficiency and gas substitution heating value, the determination of these efficiencies are necessary. This work presents the calculation processes comparing gas heating and cooking processes, versus electrical devises taking in mind several schemes and essay conditions

  1. Energy-Efficiency Policy Opportunities for Electric Motor-Driven Systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This publication is the first global analysis of energy consumption and energy efficiency potential of EMDS (electric motor- driven system). The electric motors and systems they drive are the largest single electricity end use, accounting for more than 40% of global electricity consumption. Huge energy efficiency potential was found untapped in EMDS - around 25% of EMDS electricity use could be saved cost-effectively, reducing total global electricity demand by about 10%. However, the energy efficiency of EMDS has been relatively neglected in comparison with other sustainable energy opportunities. It is crucial to scale up the operations and resources committed to realizing the vast savings potential of optimized EMDS. This paper proposes a comprehensive package of policy recommendations to help governments realize the potential for energy savings in EMDS.

  2. Energy efficiency at Hydro-Quebec: Why forget the substitution of electricity by natural gas?

    International Nuclear Information System (INIS)

    Bernard, J.-T.

    1994-01-01

    Hydro-Quebec has launched an energy program which will cost $1.9 billion and which intends to save 9.3 TWh of electricity consumption by the year 2000, equivalent to 5.6% of the forecasted electricity consumption. The program only considers electricity and ignores other energy sources. An analysis is conducted to determine whether the subsidies that Hydro-Quebec is prepared to spend in each sector of the program would be sufficient to make up the difference between the cost of electricity and that of natural gas for the end-user. A positive response to this question will allow identification of a less costly way that Hydro-Quebec could realize its energy efficiency objectives. The analysis takes into account the marginal cost of electricity production, the average cost of energy efficiency measures, electricity prices, and the prices of natural gas and of gas-burning equipment. The results of a detailed analysis of four typical cases in the residential and commercial sectors indicate that market segments exist in which an energy efficiency program that includes substitution of other forms of energy for electricity would be preferable to a simple reduction in electricity consumption. However, the rationale for the Hydro-Quebec program is that electricity prices are based on historical average costs; as a result, electricity prices are lower than marginal costs. This problem should be addressed before considering expensive energy efficiency programs where the least-cost alternative is not even considered. 5 refs., 1 fig., 2 tabs

  3. Regulation of Electric Power Generation while Improving TTP Use Efficiency

    Directory of Open Access Journals (Sweden)

    V. N. Romaniuk

    2012-01-01

    Full Text Available Taking integrated power system of theRepublicofBelarusas an example the paper considers a possibility of heat accumulator use for TPP operation in accordance with the schedule of electric power consumption while maintaining daily supply of heat energy from turbine power takes-off and without involvement of peak-loader boilers used for covering energy loads.

  4. Dynamics of electricity efficiency in commercial air-distribution systems in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Christiansson, Lena

    1996-04-01

    This paper illustrates the long-term potential for reducing future electricity demand for air-distribution in commercial buildings in Sweden. The objective has been to develop a general quantitative scenario-based framework to describe some possible paths for electricity demand for air distribution and to analyze how governmental and utility-sponsored policy measures can affect electricity demand. The focus is on improved electricity efficiency, i.e. a reduction of electricity demand for the same level of services. The results suggest that higher electricity prices will not be very effective in reducing electricity demand, whereas significant electricity savings can be reached by implementing various policy programs, particularly standards. 56 refs, 4 figs, 5 tabs

  5. The effect of merger and consolidation activities on the efficiency of electricity distribution regions in Turkey

    International Nuclear Information System (INIS)

    Çelen, Aydın

    2013-01-01

    In this study, we analyze the efficiency performances of Turkish electricity distribution companies throughout 2002 and 2009 in the stochastic frontier analysis (SFA) framework. Our more specific goal is to measure how the efficiency performances of the electricity distribution regions were affected by the mergers between distribution regions occurred in 2005. The results demonstrate that efficiencies of the companies serving to mostly the residential customers are higher than those of other companies. However, the positive impact of residential customers on the efficiencies decreased significantly following the mergers between electricity distribution companies. In contrast, the positive impact of higher customer density on efficiency also decreased, but insignificantly following the restructuring activities in the market in 2005. Our study also witnesses that the positive impact of the mergers on the efficiencies decreases as the proportion of sales to residential customers in regions increases. In contrast, the restructuring activities of 2005 increased equally the efficiencies of the companies serving in the regions with higher and lower customer densities. - Highlights: • We analyze efficiency performances of Turkish electricity distribution companies. • The efficiencies of companies serving to mostly residential customers are higher. • Positive impact of residential customers on the efficiencies dropped after mergers. • Positive impact of customer density also decreased, but insignificantly. • Positive impact of mergers on efficiency decreases as sales to residents increase

  6. Efficient buyer groups for prediction-of-use electricity tariffs

    OpenAIRE

    Robu, V; Vinyals, M; Rogers, A; Jennings, NR

    2014-01-01

    Copyright ? 2014, Association for the Advancement of Artificial Intelligence.Current electricity tariffs do not reflect the real cost that customers incur to suppliers, as units are charged at the same rate, regardless of how predictable each customers consumption is. A recent proposal to address this problem are prediction-of-use tariffs. In such tariffs, a customer is asked in advance to predict her future consumption, and is charged based both on her actual consumption and the deviation fr...

  7. Design strategy for improving the energy efficiency in series hydraulic/electric synergy system

    International Nuclear Information System (INIS)

    Ramakrishnan, R.; Hiremath, Somashekhar S.; Singaperumal, M.

    2014-01-01

    Battery is a vital subsystem in an electric vehicle with regenerative braking system. The energy efficiency of an electric vehicle is improved by storing the regenerated energy in an electric battery, during braking, and reusing it during subsequent acceleration. Battery possesses a relatively poor power density and slow charging of regenerated energy, when compared to hydro-pneumatic accumulators. A series hydraulic/electric synergy system – an energy efficient mechatronics system is proposed to overcome the drawbacks in the conventional electric vehicle with regenerative braking. Even though, electric battery provides higher energy density than the accumulator system, optimal sizing of the hydro-pneumatic accumulator and other process parameters in the system to provide better energy density and efficiency. However, a trade-off prevails between the system energy delivered and energy consumed. This gives rise to a multiple objective problem. The proposed multi-objective design optimization procedure based on an evolutionary strategy algorithm maximizes the energy efficiency of the system. The system simulation results after optimization show that, the optimal system parameters increase the energy efficiency by 3% and hydraulic regeneration efficiency by 17.3%. The suggested design methodology provides a basis for the design of a series hydraulic/electric synergy system as energy efficient and zero emission system. - Highlights: • Dynamic analysis of SHESS to investigate energy efficiency. • Optimization of system parameters based on multi-objective design strategy. • Evaluation of improvements in system energy efficiency and hydraulic regeneration energy. • Identification of conditions at which hydraulic regenerative efficiency is maximized for minimum energy consumption. • Results confirm advantages of using SHESS

  8. Heat pumps; Synergy of high efficiency and low carbon electricity

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Akio

    2010-09-15

    Heat pump is attracting wide attention for its high efficiency to utilize inexhaustible and renewable ambient heat in the environment. With its rapid innovation and efficiency improvement, this technology has a huge potential to reduce CO2 emissions by replacing currently widespread fossil fuel combustion systems to meet various heat demands from the residential, commercial and industrial sectors. Barriers to deployment such as low public awareness and a relatively long pay-back period do exist, so it is strongly recommended that each country implement policies to promote heat pumps as a renewable energy option and an effective method to combat global warming.

  9. An International Survey of Electric Storage Tank Water Heater Efficiency and Standards

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Alissa; Lutz, James; McNeil, Michael A.; Covary, Theo

    2013-11-13

    Water heating is a main consumer of energy in households, especially in temperate and cold climates. In South Africa, where hot water is typically provided by electric resistance storage tank water heaters (geysers), water heating energy consumption exceeds cooking, refrigeration, and lighting to be the most consumptive single electric appliance in the home. A recent analysis for the Department of Trade and Industry (DTI) performed by the authors estimated that standing losses from electric geysers contributed over 1,000 kWh to the annual electricity bill for South African households that used them. In order to reduce this burden, the South African government is currently pursuing a programme of Energy Efficiency Standards and Labelling (EES&L) for electric appliances, including geysers. In addition, Eskom has a history of promoting heat pump water heaters (HPWH) through incentive programs, which can further reduce energy consumption. This paper provides a survey of international electric storage water heater test procedures and efficiency metrics which can serve as a reference for comparison with proposed geyser standards and ratings in South Africa. Additionally it provides a sample of efficiency technologies employed to improve the efficiency of electric storage water heaters, and outlines programs to promote adoption of improved efficiency. Finally, it surveys current programs used to promote HPWH and considers the potential for this technology to address peak demand more effectively than reduction of standby losses alone

  10. Efficient use of power in electric arc furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, E R; Medley, J E

    1978-02-01

    The maximum transfer of electric energy to the metal in an arc furnace depends on the length of arc and the impedance of the electrical supply system from the generators to the arc itself. The use of directly-reduced sponge iron by continuous feeding results in long periods of flat-bath operation, when it is particularly important to keep a short high-current arc to get the heat into the metal rather than to the refractories, which would suffer excessive wear. By reference to a 125 ton furnace, a method of assessing the optimum operating currents and power factors and the effects of differing power-supply systems is illustrated. The importance of a low-impedance power system is illustrated, and the possibility of being unable to use the maximum furnace power without excessive refractory wear is noted. The particular problems of connecting arc-furnace loads to electrical supply systems are reviewed, and consideration is given to the problem of voltage flicker. The use of compensators is discussed with reference to existing installations, in which strong supplies from the supply-authority system are not economically available. The furnace operating characteristics, which indicate the optimum points of working, have to be checked on commissioning, and the test procedures are outlined. The optimum points for each type of charge and steel can be assessed only during their actual production. The importance of proper recording of relevant data is stressed, and reference is made to the use of computers and automatic power-input controllers.

  11. Laboratory estimation of net trophic transfer efficiencies of PCB congeners to lake trout (Salvelinus namaycush) from its prey

    Science.gov (United States)

    Madenjian, Charles P.; Rediske, Richard R.; O'Keefe, James P.; David, Solomon R.

    2014-01-01

    A technique for laboratory estimation of net trophic transfer efficiency (γ) of polychlorinated biphenyl (PCB) congeners to piscivorous fish from their prey is described herein. During a 135-day laboratory experiment, we fed bloater (Coregonus hoyi) that had been caught in Lake Michigan to lake trout (Salvelinus namaycush) kept in eight laboratory tanks. Bloater is a natural prey for lake trout. In four of the tanks, a relatively high flow rate was used to ensure relatively high activity by the lake trout, whereas a low flow rate was used in the other four tanks, allowing for low lake trout activity. On a tank-by-tank basis, the amount of food eaten by the lake trout on each day of the experiment was recorded. Each lake trout was weighed at the start and end of the experiment. Four to nine lake trout from each of the eight tanks were sacrificed at the start of the experiment, and all 10 lake trout remaining in each of the tanks were euthanized at the end of the experiment. We determined concentrations of 75 PCB congeners in the lake trout at the start of the experiment, in the lake trout at the end of the experiment, and in bloaters fed to the lake trout during the experiment. Based on these measurements, γ was calculated for each of 75 PCB congeners in each of the eight tanks. Mean γ was calculated for each of the 75 PCB congeners for both active and inactive lake trout. Because the experiment was replicated in eight tanks, the standard error about mean γ could be estimated. Results from this type of experiment are useful in risk assessment models to predict future risk to humans and wildlife eating contaminated fish under various scenarios of environmental contamination.

  12. Evaluation of discrete modeling efficiency of asynchronous electric machines

    OpenAIRE

    Byczkowska-Lipińska, Liliana; Stakhiv, Petro; Hoholyuk, Oksana; Vasylchyshyn, Ivanna

    2011-01-01

    In the paper the problem of effective mathematical macromodels in the form of state variables intended for asynchronous motor transient analysis is considered. Their comparing with traditional mathematical models of asynchronous motors including models built into MATLAB/Simulink software was carried out and analysis of their efficiency was conducted.

  13. 10 CFR Appendix B to Subpart B of... - Uniform Test Method for Measuring Nominal Full Load Efficiency of Electric Motors

    Science.gov (United States)

    2010-01-01

    ... Efficiency of Electric Motors B Appendix B to Subpart B of Part 431 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Electric Motors Pt. 431... Efficiency of Electric Motors 1. Definitions. Definitions contained in §§ 431.2 and 431.12 are applicable to...

  14. Quality studies of the energy in the electric net of the gathering warehouse of reusable parts and contaminate oils of the nuclear power plant Laguna Verde

    International Nuclear Information System (INIS)

    Tijerina S, F.; Vargas A, A.; Cardenas J, J.

    2012-10-01

    In the industry exist the high costs by faults of electronic and electric equipment s, due to during the design process, installation, tests and operation of these equipment s, is not had appropriate detection equipment to carry out quality studies of the energy. These studies give an important support to know that occurs in an electric net, the cause of the anomalous behavior of the equipment s and this way to avoid the expensive faults carrying out necessary engineering adaptations in an electric net. The elements of the electricity that are determined are the tension, current and frequency that are inside acceptable operational parameters that facilitate the operation and constant operation of the equipment s, free of interruptions and failures. The application of the quality studies of the energy is growing little by little in Mexico for the problems solution in the equipment s. This field is also developing new techniques and technologies integrated in the equipment s for its monitoring detection and protection. The present work offers the results of the first Quality Study of the Energy in the nuclear power plant of Laguna Verde to solve the problem in the gathering warehouse of reusable parts and contaminate oils, in which the failure of the two radiation monitors of the gassy effluent of ventilation HVAC of the warehouse took place. (Author)

  15. Incorporating energy efficiency into electric power transmission planning: A western United States case study

    International Nuclear Information System (INIS)

    Barbose, Galen L.; Sanstad, Alan H.; Goldman, Charles A.

    2014-01-01

    Driven by system reliability goals and the need to integrate significantly increased renewable power generation, long-range, bulk-power transmission planning processes in the United States are undergoing major changes. At the same time, energy efficiency is an increasing share of the electricity resource mix in many regions, and has become a centerpiece of many utility resource plans and state policies as a means of meeting electricity demand, complementing supply-side sources, and reducing carbon dioxide emissions from the electric power system. The paper describes an innovative project in the western United States to explicitly incorporate end-use efficiency into load forecasts – projections of electricity consumption and demand – that are a critical input into transmission planning and transmission planning studies. Institutional and regulatory background and context are reviewed, along with a detailed discussion of data sources and analytical procedures used to integrate efficiency into load forecasts. The analysis is intended as a practical example to illustrate the kinds of technical and institutional issues that must be addressed in order to incorporate energy efficiency into regional transmission planning activities. - Highlights: • Incorporating energy efficiency into electric power transmission planning is an emergent analytical and policy priority. • A new methodology for this purpose was developed and applied in the western U.S. transmission system. • Efficiency scenarios were created and incorporated into multiple load forecasts. • Aggressive deployment of efficiency policies and programs can significantly reduce projected load. • The approach is broadly applicable in long-range transmission planning

  16. Experience with Energy Efficiency Requirements for Electrical Equipment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This publication has been produced as part of the work programme in support of the Gleneagles Plan of Action (GPOA), where the IEA was requested to 'undertake a study to review existing global appliance standards and codes'. In accordance with the G8 request, this study investigates the coverage and impact of forms of minimum energy performance standards (MEPS) and comparative energy labelling programmes; which comprise the cornerstone of most IEA countries national energy efficiency strategy. This scope also reflects governments' aspirations to achieve ambitious targets for reducing greenhouse gas emissions. As a result, this study does not address endorsement labelling and associated voluntary programmes, although these are also important policy tools for national energy efficiency strategies.

  17. Measuring efficiency and productivity change (PTF) in the Peruvian electricity distribution companies after reforms

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Reyes, Raul [Organismo Supervisor de la Inversion en Energia y Mineria, Osinergmin (Peru); Tovar, Beatriz [Infrastructure and Transport Research Group (EIT), Department of Applied Economics, University of Palmas de Gran Canaria (Spain)

    2009-06-15

    This paper analyzes the evolution of productivity of the electricity distribution companies in Peru, to assess whether reforms have improved the efficiency in this sector. The paper also identifies potential sources of productivity changes, based on market restructuring the electricity sector and changes in property. To do this, we rely on a set of data for 14 distribution companies, for the period 1996-2006. Our analysis suggests that improvements in the efficiency and productivity of electricity distribution in Peru have occurred, and that there is a relationship between the restructuring of distribution sector and the enhancement of productivity. (author)

  18. Opportunities for Efficiency Improvements in the U.S. Electricity Transmission and Distribution System

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Onar, Omer C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kirkham, Harold [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fisher, Emily [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Burkes, Klaehn [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Starke, Michael R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mohammed, Olama [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Weeks, George [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-04-01

    Since 2000, more than 172 quads of electricity have been transmitted on the US transmission and distribution (T&D) grid. Given this significant amount of energy flow, establishing and maintaining an efficient T&D grid is paramount. As shown in the figure below, the total percentage of overall losses in the US electric grid is approximately 6% (5.12% in 2012) (30% lower than the world average since 2000). While these efficiency losses appear to be relatively small from a percentage perspective, the total estimated electricity loss during this time is 10.8 quads.

  19. Measuring efficiency and productivity change (PTF) in the Peruvian electricity distribution companies after reforms

    International Nuclear Information System (INIS)

    Perez-Reyes, Raul; Tovar, Beatriz

    2009-01-01

    This paper analyzes the evolution of productivity of the electricity distribution companies in Peru, to assess whether reforms have improved the efficiency in this sector. The paper also identifies potential sources of productivity changes, based on market restructuring the electricity sector and changes in property. To do this, we rely on a set of data for 14 distribution companies, for the period 1996-2006. Our analysis suggests that improvements in the efficiency and productivity of electricity distribution in Peru have occurred, and that there is a relationship between the restructuring of distribution sector and the enhancement of productivity. (author)

  20. The effect of economic factors and energy efficiency programs on residential electricity consumption

    Science.gov (United States)

    Sakai, Mihoko

    Many countries have implemented policies to correct market and behavioral failures that lead to inefficient energy use. It is important to know what factors and policies can effectively overcome such failures and improve energy efficiency; however, a comprehensive analysis has been difficult because of data limitations. Using state scores compiled by American organizations recently, and adopting fixed-effects regression models, I analyze the joint impacts of relevant factors and policy programs on residential electricity consumption in each U.S. state. The empirical results reveal that increases in electricity price have small and negative effects, and increases in personal income have positive effects on residential electricity sales per capita (a measure of energy efficiency). The results suggest that it may take time for economic factors to affect electricity sales. The effects of personal income suggest the difficulty of controlling residential electricity consumption; however, they also imply that there is some room in households to reduce electricity use. The study also finds that programs and budgets of several policies seem to be associated with electricity sales. The estimates from a model including interaction terms suggest the importance of including multiple policies when analyzing and designing policies to address electricity efficiency. The results also imply the possibility of rebound effects of some policies, whereby improvements in energy efficiency lead to increases in energy consumption due to the associated lower per unit cost. Future studies should analyze both short-term and long-term effects of economic factors and policies, based on improved and accumulated time series and panel data, in order to design more effective policies for improving residential electricity efficiency.

  1. Efficiency snakes and energy ladders: A (meta-)frontier demand analysis of electricity consumption efficiency in Chinese households

    International Nuclear Information System (INIS)

    Broadstock, David C.; Li, Jiajia; Zhang, Dayong

    2016-01-01

    Policy makers presently lack access to quantified estimates – and hence an explicit understanding – of energy consumption efficiency within households, creating a potential gap between true efficiency levels and the necessarily assumed efficiency levels that policy makers adopt in designing and implementing energy policy. This paper attempts to fill this information gap by empirically quantifying electricity consumption efficiency for a sample of more than 7,000 households. Adopting the recently introduced ‘frontier demand function’ due to Filippini and Hunt (2011) but extending it into the metafrontier context – to control for structural heterogeneity arising from location type – it is shown that consumption efficiency is little more than 60% on average. This implies huge potential for energy reduction via the expansion of schemes to promote energy efficiency. City households, which are the wealthiest in the sample, are shown to define the metafrontier demand function (and hence have the potential to be the most efficient households), but at the same time exhibit the largest inefficiencies. These facts together allow for a potential refinement on the household energy ladder concept, suggesting that wealth affords access to the best technologies thereby increasing potential energy efficiency (the ‘traditional view of the household energy ladder), but complementary to this these same households are most inefficient. This has implications for numerous areas of policy, including for example the design of energy assistance schemes, identification of energy education needs/priorities as well more refined setting of subsidies/tax-credit policies. - Highlights: •Frontier demand functions are estimated for a sample of 7102 Chinese households. •Metafrontier methods capture heterogeneity arising from urban form (e.g. cities, towns and villages). •Wealthier houses have higher efficiency potential, but are in fact less efficient in their consumption of

  2. Calorimetric Measurement for Internal Conversion Efficiency of Photovoltaic Cells/Modules Based on Electrical Substitution Method

    Science.gov (United States)

    Saito, Terubumi; Tatsuta, Muneaki; Abe, Yamato; Takesawa, Minato

    2018-02-01

    We have succeeded in the direct measurement for solar cell/module internal conversion efficiency based on a calorimetric method or electrical substitution method by which the absorbed radiant power is determined by replacing the heat absorbed in the cell/module with the electrical power. The technique is advantageous in that the reflectance and transmittance measurements, which are required in the conventional methods, are not necessary. Also, the internal quantum efficiency can be derived from conversion efficiencies by using the average photon energy. Agreements of the measured data with the values estimated from the nominal values support the validity of this technique.

  3. Electricity supply efficiency and organizational growth and profitability in Lagos, Nigeria

    Science.gov (United States)

    Adeleke, Adedeji Tajudeen

    A modern and efficient infrastructure is a basic necessity for economic development and integration into the global economy. The specific problem was the inadequate and unreliable supply of electricity to manufacturing corporations in Lagos, Nigeria. The purpose of the current quantitative correlational research study was to examine if there was a correlation between electricity supply efficiency and organizational growth and profitability in manufacturing corporations in Lagos, Nigeria. The population of the current correlational research study involved 28 out of 34 manufacturing corporations from various industrial sectors in Lagos, Nigeria, that are listed and traded on the Nigerian Stock Exchange. Spearman rho correlations were used to assess the relationships between independent variables of electricity supply efficiency levels and the dependent variables of organizational growth and profitability. The result of the correlational analysis of the data revealed that there was a statistically significant, strong positive correlation between the Average Gross Income (1998-2007) and Average Actual Electricity supply efficiency level (1998-2007), rho = 0.57; p = 0.002. A statistically significant, strong positive correlation was found between the Average Balance Sheet Size (1998-2007) and Average Actual Electricity Supply Efficiency Level (1998-2007), rho = 0.54; p = 0.003. A statistically significant, strong positive correlation between the Average Profit After Tax (1998-2007) and Average Actual Electricity Supply Efficiency Level (1998-2007), rho = 0.60; p = 0.001, was found. No statistically significant correlation between the Average Return on Investment (1998-2007) and Average Actual Electricity supply efficiency level (1998-2007), rho = 0.19; p = 0.33, was discovered.

  4. Competitiveness of grid-connected solar electricity in Sweden - as seen from the perspective of the utilities and the net owners; Konkurrenskraft foer naetansluten solel i Sverige - sett ur kraftfoeretagens och naetaegarnas perspektiv

    Energy Technology Data Exchange (ETDEWEB)

    Carlstedt, Nils-Eric [Vattenfall Power Consultant AB, Stockholm (Sweden); Karlsson, Bjoern; Kjellsson, Elisabeth; Samuelsson, Olof [Faculty of Engineering (LTH), Lund University, Lund (Sweden); Neij, Lena [International Institute for Industrial Environmental Economics, Lund University, Lund (Sweden)

    2006-12-15

    The objective of this report was to analyse the competitiveness of grid-connected solar power in Sweden - and specifically the competitiveness for energy companies and net owners. In theory, solar power could to a large extent fulfil the electricity demand in Sweden, especially in the summer. However, the high cost of solar cells is a major barrier to implementation. Future technology development and increased efficiency could, however, lead to important cost reductions. The question is if such expected cost reductions would make grid-connected solar power a preferable investment option for energy companies and an interesting alternative for the net owners. The results of the study show that solar power will not be a competitive alternative for the energy companies in Sweden, not in 2020 and probably not in 2050. Other alternatives such as new investments in wind turbines and bio-mass based technology options will be producing electricity at a lower cost. Moreover, solar power will have an unfavourable production profile, generating power in the summertime when less needed. However, by using the reservoirs of the hydro power systems in Sweden as storage capacity, approximately 5 TWh solar power could be allowed in the Swedish electricity system. The results of the study indicate that solar power could have a positive effect on the electricity distribution system since distributed generation will result in lower losses in the system. Moreover, solar power will be produced during daytime when the electricity demand will peak. One of the main challenges for the net owners would be to design the net in such a way that the net and the solar cells could work together in the best possible way. Another challenge would be the high cost for connecting the solar cells to the grid; this cost needs to be reduced. Looking instead at the house-owners as possible investors, solar cells appear as a much more attractive alternative for the future, the value of the solar power is

  5. Cost efficiency and optimal scale of electricity distribution firms in Taiwan: An application of metafrontier analysis

    International Nuclear Information System (INIS)

    Huang, Y.-J.; Chen, K.-H.; Yang, C.-H.

    2010-01-01

    This paper analyzes the cost efficiency and optimal scale of Taiwan's electricity distribution industry. Due to the substantial difference in network density, firms may differ widely in production technology. We employ the stochastic metafrontier approach to estimate the cost efficiency of 24 distribution units during the period 1997-2002. Empirical results find that the average cost efficiency is overestimated using the traditional stochastic frontier model, especially for low density regions. The average cost efficiency of the high density group is significantly higher than that of the low density group as it benefits from network economies. This study also calculates both short-term and long-term optimal scales of electricity distribution firms, lending policy implications for the deregulation of the electricity distribution industry.

  6. Seasonal and Topographic Variation in Net Primary Productivity and Water Use Efficiency in a Southwest Sky Island Fores

    Science.gov (United States)

    Murphy, P.; Minor, R. L.; Sanchez-Canete, E. P.; Potts, D. L.; Barron-Gafford, G.

    2016-12-01

    Western North American Forests represent an uncertain sink for atmospheric carbon. While understanding of the physical drivers of productivity in these forests has grown in the last decade, the relative influence of topographic position in the complex terrain of montane systems remains understudied. The high-latitude mixed conifer forest ecosystems of the southern Arizona Madrean Sky Islands are characterized by low precipitation, high annual variation in temperature, and heterogeneous topography. Eddy covariance measurements these forests show distinct seasonal trends due to temperature and bi-modal precipitation patterns, but these measurements are unable to resolve potential differences in physiological function on opposing north and south aspects within the footprint of the tower. Most of the year, north aspects receive less energy input due to the oblique angle of incoming solar radiation, leading to a divergence in soil moistures and temperatures. However, overall movement of energy and material is much higher on these north aspects on an annual basis. The implications of these differences for net primary productivity (NPP) and water use efficiency (WUE) are poorly addressed in the literature. We evaluated the relative control that topography has on the physical environment (soil moisture and temperature) and how these factors affect water stress, NPP, and WUE. We combined leaf-level measurements of photosynthesis and transpiration with other physiological and meteorological measurements to determine how the dominant vegetation functions as a result of microclimatic conditions. Initial results from the spring and summer measurement periods suggest topographical differences in microclimate, resulting in differences in NPP in the spring, but not the summer. Also, each of the three species on the same aspect responded differently to the same microclimatic conditions, underscoring interspecific variation at the site. How might these patterns change throughout an

  7. The efficiency of direct torque control for electric vehicle behavior improvement

    Directory of Open Access Journals (Sweden)

    Gasbaoui Brahim

    2011-01-01

    Full Text Available Nowadays the electric vehicle motorization control takes a great interest of industrials for commercialized electric vehicles. This paper is one example of the proposed control methods that ensure both safety and stability the electric vehicle by the means of Direct Torque Control (DTC. For motion of the vehicle the electric drive consists of four wheels: two front ones for steering and two rear ones for propulsion equipped with two induction motors, due to their lightweight simplicity and high performance. Acceleration and steering are ensured by the electronic differential, permitting safe and reliable steering at any curve. The direct torque control ensures efficiently controlled vehicle. Electric vehicle direct torque control is simulated in MATLAB SIMULINK environment. Electric vehicle (EV demonstrated satisfactory results in all type of roads constraints: straight, ramp, downhill and bends.

  8. Customer-economics of residential photovoltaic systems (Part 1): The impact of high renewable energy penetrations on electricity bill savings with net metering

    International Nuclear Information System (INIS)

    Darghouth, Naïm R.; Barbose, Galen; Wiser, Ryan H.

    2014-01-01

    Residential photovoltaic (PV) systems in the US are often compensated at the customer's underlying retail electricity rate through net metering. Given the uncertainty in future retail rates and the inherent links between rates and the customer–economics of behind-the-meter PV, there is growing interest in understanding how potential changes in rates may impact the value of bill savings from PV. In this article, we first use a production cost and capacity expansion model to project California hourly wholesale electricity market prices under two potential electricity market scenarios, including a reference and a 33% renewables scenario. Second, based on the wholesale electricity market prices generated by the model, we develop retail rates (i.e., flat, time-of-use, and real-time pricing) for each future scenario based on standard retail rate design principles. Finally, based on these retail rates, the bill savings from PV is estimated for 226 California residential customers under two types of net metering, for each scenario. We find that high renewable penetrations can drive substantial changes in residential retail rates and that these changes, together with variations in retail rate structures and PV compensation mechanisms, interact to place substantial uncertainty on the future value of bill savings from residential PV. - Highlights: • We investigate the impact of high renewables on customer economics of solar. • We model three types of residential retail electricity rates. • Based on the rates, we calculate the bill savings from photovoltaic (PV) generation. • High renewables penetration can lead to lower bill savings with time-varying rates. • There is substantial uncertainty in the future bill savings from residential PV

  9. Potential efficiencies of open- and closed-cycle CO, supersonic, electric-discharge lasers

    Science.gov (United States)

    Monson, D. J.

    1976-01-01

    Computed open- and closed-cycle system efficiencies (laser power output divided by electrical power input) are presented for a CW carbon monoxide, supersonic, electric-discharge laser. Closed-system results include the compressor power required to overcome stagnation pressure losses due to supersonic heat addition and a supersonic diffuser. The paper shows the effect on the system efficiencies of varying several important parameters. These parameters include: gas mixture, gas temperature, gas total temperature, gas density, total discharge energy loading, discharge efficiency, saturated gain coefficient, optical cavity size and location with respect to the discharge, and supersonic diffuser efficiency. Maximum open-cycle efficiency of 80-90% is predicted; the best closed-cycle result is 60-70%.

  10. Efficiency Analysis of German Electricity Distribution Utilities : Non-Parametric and Parametric Tests

    OpenAIRE

    von Hirschhausen, Christian R.; Cullmann, Astrid

    2005-01-01

    Abstract This paper applies parametric and non-parametric and parametric tests to assess the efficiency of electricity distribution companies in Germany. We address traditional issues in electricity sector benchmarking, such as the role of scale effects and optimal utility size, as well as new evidence specific to the situation in Germany. We use labour, capital, and peak load capacity as inputs, and units sold and the number of customers as output. The data cover 307 (out of 553) ...

  11. Highly-Efficient Thermoelectronic Conversion of Heat and Solar Radiation to Electric Power

    OpenAIRE

    Meir, Stefan

    2013-01-01

    Thermionic energy conversion has long been a candidate to convert solar radiation and the combustion heat of fossil fuels into electricity at high efficiencies. However, the formation of electron space charges has prevented the widespread use of the principle since its was first suggested in 1915. In this work, a novel mechanism to suppress the effects of the space charge was investigated: the acceleration of electrons in a special configuration of electric and magnetic fields. This work d...

  12. High efficiency thermal to electric energy conversion using selective emitters and spectrally tuned solar cells

    Science.gov (United States)

    Chubb, Donald L.; Flood, Dennis J.; Lowe, Roland A.

    1992-01-01

    Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1500 K. Depending on the nature of parasitic losses, overall thermal-to-electric conversion efficiencies greater than 20 percent are feasible.

  13. Eco-efficiency optimization of Hybrid Electric Vehicle based on response surface method and genetic algorithm

    OpenAIRE

    Nzisabira, Jonathan; Louvigny, Yannick; Duysinx, Pierre

    2008-01-01

    The electric vehicles (EV) and sometimes the hybrid electric vehicle (HEV) technologies are environmentally very efficient but can not succeed on the market because of a smaller ability to satisfy customer’s requirements. Comparison of clean technologies in automotive and transportation systems has been measured using different analysis tools such as LCA (life cycle analysis). However, these instruments never account for the user’s satisfaction which partly explains the market acceptance prob...

  14. Evaluating games console electricity use : technologies and policy options to improve energy efficiency.

    OpenAIRE

    Webb, Amanda E.

    2016-01-01

    Energy efficiency regulations and standards are increasingly being used as an approach to reduce the impact of appliances on climate change. Each new generation of games consoles is significantly different to the last and their cumulative electricity use has risen due to improved performance and functionality and increasing sales. As a result, consoles have been identified in the EU, US and Australia as a product group with the potential for significant electricity savings. However, there is ...

  15. High Efficiency, Low Cost Parabolic Dish System for Cogeneration of Electricity and Heat

    Science.gov (United States)

    Chayet, Haim; Lozovsky, Ilan; Kost, Ori; Loeckenhoff, Ruediger; Rasch, Klaus-Dieter

    2010-10-01

    Highly efficient combined heat and power generating system based on CPV technology using unique dish design consisting of multiple simple flat mirrors mounted on a plastic parabolic surface. The dish of total aperture area of 11 m2 focuses 10.3 kWp onto a heat and electricity generating receiver. The receiver comprises a water cooled, dense triple junction cell array of 176 cm2 aperture area. A unique arrangement of the cells compensates for the non-uniformity of the reflected flux. Depending on the flow rate, the temperature of the hot water can be adjusted to suit from temperatures for domestic use, to temperatures suited for process heat. The output of 2.3 kWp electrical and 5.5 kWp thermal power from one dish system represent 20 to 21% electrical and 50% thermal conversion efficiency adding to 70% overall system efficiency.

  16. Transmission prices in the electric system. Technical constraints and economic efficiency

    International Nuclear Information System (INIS)

    Polidori, P.

    1999-01-01

    This article analyses the two main models at the core of today's theoretical discussion on transmission pricing in electricity sectors under competition. The first aim of the paper is showing how technical constraints that characterise transmission systems may affect energy production and transmission and therefore the definition of the price system for using the electric grid. The second aim of the paper is showing how it is possible to suggest solutions, although not free from limitations, that can be used for an efficient management of electric systems characterised by generation and consumption sectors under competition [it

  17. Improved quantum efficiency models of CZTSe: GE nanolayer solar cells with a linear electric field.

    Science.gov (United States)

    Lee, Sanghyun; Price, Kent J; Saucedo, Edgardo; Giraldo, Sergio

    2018-02-08

    We fabricated and characterized CZTSe:Ge nanolayer (quantum efficiency for Ge doped CZTSe devices. The linear electric field model is developed with the incomplete gamma function of the quantum efficiency as compared to the empirical data at forward bias conditions. This model is characterized with a consistent set of parameters from a series of measurements and the literature. Using the analytical modelling method, the carrier collection profile in the absorber is calculated and closely fitted by the developed mathematical expressions to identify the carrier dynamics during the quantum efficiency measurement of the device. The analytical calculation is compared with the measured quantum efficiency data at various bias conditions.

  18. An analysis of the Spanish electrical utility industry. Economies of scale, technological progress and efficiency

    International Nuclear Information System (INIS)

    Arcos, Angel; De Toledo, Pablo Alvarez

    2009-01-01

    In this paper we propose a model to explain the behaviour of the Spanish electrical utility industry during the period 1987-1997, under the then existing regulatory system (Marco Legal Estable). The paper will study the presence of economies of scale, the effect of technological progress and the differences in the efficiency of the different companies within the market. The paper concludes that the Spanish electrical utility industry was not, in fact, characterized by economies of scale during this period, but witnessed a great improvement in efficiency within that period. All the critical market factors remind stable. (author)

  19. A modified Wheeler cap method for radiation efficiency measurement of balanced electrically small antennas

    DEFF Research Database (Denmark)

    Zhang, Jiaying; Pivnenko, Sergey; Breinbjerg, Olav

    2010-01-01

    , but not for balanced antennas like loops or dipoles. In this paper, a modified Wheeler cap method is proposed for the radiation efficiency measurement of balanced electrically small antennas and a three-port network model of the Wheeler cap measurement is introduced. The advantage of the modified method...... is that it is wideband, thus does not require any balun, and both the antenna input impedance and radiation efficiency can be obtained. An electrically small loop antenna and a wideband dipole were simulated and measured according to the proposed method and the results of measurements and simulations are presented...

  20. Public policy analysis of energy efficiency and load management in changing electricity business

    Energy Technology Data Exchange (ETDEWEB)

    Vine, E. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States). Energy Analysis Dept.; Hamrin, J. [Centre for Resource Solutions (United States); Eyre, N. [Energy Savings Trust (United Kingdom); Crossley, D.; Maloney, M.; Watt, G. [Energy Futures Australia Pty Ltd (Australia)

    2003-04-01

    The focus of this paper is (1) the potential effectiveness of the reform of the electricity industry on promoting energy efficiency and load management, and (2) the potential effectiveness of new mechanisms for promoting energy efficiency and load management. Many countries are initiating reforms of their power sectors to stimulate private investment, increase operation and management efficiencies, and lower the cost of power. These countries are unbundling vertically integrated utilities into distinct generation, transmission, distribution and retail supply companies; introducing commercial management principles to government-owned monopolies; and in many cases transferring operation or ownership to private companies. Electric industry restructuring may force regulators and policy makers to re-examine existing mechanisms for promoting load management and energy efficiency. In some cases, electric industry restructuring replaces the long-standing relationship between a single monopoly provider and protected customer franchise with a new set of relationships among retail electricity suppliers and customers who may now be free to choose suppliers. In these types of situations, markets, not government regulators and utility monopolies, are seen as determining future energy production and consumption decisions. However, it is uncertain whether this type of restructuring will overcome important market barriers to energy efficiency that limit markets for energy-efficient products and services from functioning effectively. As a result of these barriers, a large, untapped potential for cost-effective energy-efficiency investments exists. Supporters of public policies argue that energy-efficiency programs are an appropriate government strategy to capture economic efficiencies that the market cannot secure unassisted. (author)

  1. Public policy analysis of energy efficiency and load management in changing electricity businesses

    Energy Technology Data Exchange (ETDEWEB)

    Vine, Edward; Hamrin, Jan; Eyre, Nick; Crossley, David; Maloney, Michelle; Watt, Greg

    2003-04-01

    The focus of this paper is (1) the potential effectiveness of the reform of the electricity industry on promoting energy efficiency and load management, and (2) the potential effectiveness of new mechanisms for promoting energy efficiency and load management. Many countries are initiating reforms of their power sectors to stimulate private investment, increase operation and management efficiencies, and lower the cost of power. These countries are unbundling vertically integrated utilities into distinct generation, transmission, distribution and retail supply companies; introducing commercial management principles to government-owned monopolies; and in many cases transferring operation or ownership to private companies. Electric industry restructuring may force regulators and policy makers to re-examine existing mechanisms for promoting load management and energy efficiency. In some cases, electric industry restructuring replaces the long-standing relationship between a single monopoly provider and protected customer franchise with a new set of relationships among retail electricity suppliers and customers who may now be free to choose suppliers. In these types of situations, markets, not government regulators and utility monopolies, are seen as determining future energy production and consumption decisions. However, it is uncertain whether this type of restructuring will overcome important market barriers to energy efficiency that limit markets for energy-efficient products and services from functioning effectively. As a result of these barriers, a large, untapped potential for cost-effective energy-efficiency investments exists. Supporters of public policies argue that energy-efficiency programs are an appropriate government strategy to capture economic efficiencies that the market cannot secure unassisted.

  2. Public policy analysis of energy efficiency and load management in changing electricity businesses

    International Nuclear Information System (INIS)

    Vine, Edward; Hamrin, Jan; Eyre, Nick; Crossley, David; Maloney, Michelle; Watt, Greg

    2003-01-01

    The focus of this paper is (1) the potential effectiveness of the reform of the electricity industry on promoting energy efficiency and load management, and (2) the potential effectiveness of new mechanisms for promoting energy efficiency and load management. Many countries are initiating reforms of their power sectors to stimulate private investment, increase operation and management efficiencies, and lower the cost of power. These countries are unbundling vertically integrated utilities into distinct generation, transmission, distribution and retail supply companies; introducing commercial management principles to government-owned monopolies; and in many cases transferring operation or ownership to private companies. Electric industry restructuring may force regulators and policy makers to re-examine existing mechanisms for promoting load management and energy efficiency. In some cases, electric industry restructuring replaces the long-standing relationship between a single monopoly provider and protected customer franchise with a new set of relationships among retail electricity suppliers and customers who may now be free to choose suppliers. In these types of situations, markets, not government regulators and utility monopolies, are seen as determining future energy production and consumption decisions. However, it is uncertain whether this type of restructuring will overcome important market barriers to energy efficiency that limit markets for energy-efficient products and services from functioning effectively. As a result of these barriers, a large, untapped potential for cost-effective energy-efficiency investments exists. Supporters of public policies argue that energy-efficiency programs are an appropriate government strategy to capture economic efficiencies that the market cannot secure unassisted

  3. Essays on the efficient integration of renewable energies into electricity markets

    International Nuclear Information System (INIS)

    Obermueller, Frank

    2018-01-01

    The dissertation ''Essay on the Efficient Integration of Renewable Energies into Electricity Markets'' consists of five research articles which shed light on the efficient integration of renewable energies into electricity markets. A major share of renewable energies has characteristics which differ from classical conventional generation technologies. The uncertain weather-dependent characteristics in combination with almost-zero marginal generation costs raise new challenges to some parts of the electricity system. On the other side, the promotion of renewable energies seems promising to achieve the Energy Transition targets and reduce Germany's CO 2 -emissions. This becomes relevant in the light of the 2015 UN Climate Change Conference which negotiated the Paris Agreement to tackle climate change, e.g. by the restriction of global warming to a maximum of 2 C, and translate to CO 2 -reduction efforts, especially for the carbon-dioxide intense electricity sectors. The five research papers focusing on different aspects and potential inefficiencies of the renewable energy market integration. The focus can roughly be separated into temporal and regional efficiency examinations. The temporal efficiency is subject to paper 1, paper 2 and paper 3. The regional efficiency is subject to paper 5 which is based on the preliminary findings and the generated dataset in paper 4.

  4. Essays on the efficient integration of renewable energies into electricity markets

    Energy Technology Data Exchange (ETDEWEB)

    Obermueller, Frank

    2018-01-09

    The dissertation ''Essay on the Efficient Integration of Renewable Energies into Electricity Markets'' consists of five research articles which shed light on the efficient integration of renewable energies into electricity markets. A major share of renewable energies has characteristics which differ from classical conventional generation technologies. The uncertain weather-dependent characteristics in combination with almost-zero marginal generation costs raise new challenges to some parts of the electricity system. On the other side, the promotion of renewable energies seems promising to achieve the Energy Transition targets and reduce Germany's CO{sub 2}-emissions. This becomes relevant in the light of the 2015 UN Climate Change Conference which negotiated the Paris Agreement to tackle climate change, e.g. by the restriction of global warming to a maximum of 2 C, and translate to CO{sub 2}-reduction efforts, especially for the carbon-dioxide intense electricity sectors. The five research papers focusing on different aspects and potential inefficiencies of the renewable energy market integration. The focus can roughly be separated into temporal and regional efficiency examinations. The temporal efficiency is subject to paper 1, paper 2 and paper 3. The regional efficiency is subject to paper 5 which is based on the preliminary findings and the generated dataset in paper 4.

  5. Fuzzy colored petri nets and their application to efficient design and V and V of fuzzy logic controllers

    International Nuclear Information System (INIS)

    Son, Han Seong; Seong, Poong Hyun

    1998-01-01

    Generally, FLC design causes the designer to spend too much efforts and time. If a design support is provided to apply various membership functions to and simulate a FLC without coding at the early development stage, the cost problem may be solved to a remarkable degree. In order to offer the systematic approach to support FLC design, Fuzzy Colored Petri Nets (FCPN) is introduced as design support in this work. The feasibility of FCPN is demonstrated through a controller design example

  6. Efficiency evaluation of gas fuelled and electric driven buses in the public transport sector

    Energy Technology Data Exchange (ETDEWEB)

    Aigner, Tobias Alexander

    2013-07-01

    The following report evaluates the efficiency of gas fuelled and electric driven buses in the public transport sector on a theoretical basis. The results indicate that the combination of CHP power plants and electric driven buses reach an overall efficiency of about 51% throughout the production chain (Well-to-Wheel), including heat distribution losses. The overall Well-to-Wheel efficiency for conventional gas turbines without heat recovery decreases to around 28%. For gas fuelled buses the Well-to-Wheel efficiency is about 30%. The Co2-emissions are evaluated based on the example of a #Left Double Quotation Mark#Volvo B10L CNG#Right Double Quotation Mark# gas bus and the electric driven #Left Double Quotation Mark#Eurabus 600#Right Double Quotation Mark#. The low energy consumption of the electric driven bus results in Co2-emissions of only 181.4 g Co2/km (Grid-to-Wheel). Depending on the utilised power plant technology the overall Co2-emissions (Well-to-Wheel) amount to 307.5 g Co2/km for a CHP power plant and 553.5 g Co2/km for a conventional gas turbine. On the other hand, gas fuelled buses emit about 1.25 kg Co2/km (Tank-to-Wheel), which is eightfold the emissions of an electrical bus. The Well-to-Tank emissions further increase to about 1.32 kg Co2/km. The emission calculation is based on real gas consumption data from a Norwegian public transport utility. The results indicate that the combination of CHP plants and electrical buses provide a much higher efficiency while reducing Co2-emissions. (author)

  7. A Traction Control Strategy with an Efficiency Model in a Distributed Driving Electric Vehicle

    OpenAIRE

    Lin, Cheng; Cheng, Xingqun

    2014-01-01

    Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the tw...

  8. Efficient promotion of electricity production from offshore wind; Effiziente Foerderung der Stromerzeugung aus Offshore-Wind

    Energy Technology Data Exchange (ETDEWEB)

    Panzer, Christian; Auer, Hans; Lettner, Georg [Technische Univ. Wien (Austria). Energy Economics Group (EEG)

    2014-03-15

    Efficient promotion of electricity production from offshore wind stands in dynamic relationship with various influence factors, the most important of which are promotion instruments, topographic givens, regulation of grid connection, and supraregional market integration concepts. Using three case studies from different countries to highlight national differences in the promotion of offshore wind power plants the present analysis points out ways of improving the efficiency of promotion instruments.

  9. Secure and Efficient Electricity Supply. During the Transition to Low Carbon Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    Electricity shortages can paralyse our modern economies. All governments fear rolling black-outs and their economic consequences, especially in economies increasingly based on digital technologies. Over the last two decades, the development of markets for power has produced cost reduction, technological innovation, increased cross border trade and assured a steady supply of electricity. Now, IEA countries face the challenge of maintaining security of electricity supply during the transition to low-carbon economies. Low-carbon policies are pushing electricity markets into novel territories at a time when most of the generation and network capacity will have to be replaced. Most notably, wind and solar generation, now an integral part of electricity markets, can present new operating and investment challenges for generation, networks and the regional integration of electricity markets. In addition, the resilience of power systems facing more frequent natural disasters is also of increasing concern. IEA Ministers mandated the Secretariat to work on the Electricity Security Action Plan (ESAP), expanding to electricity the energy security mission of the IEA. This paper outlines the key conclusions and policy recommendations to ''keep the lights on'' while reducing CO2 emissions and increasing the efficiency.

  10. Displacement efficiency of alternative energy and trans-provincial imported electricity in China.

    Science.gov (United States)

    Hu, Yuanan; Cheng, Hefa

    2017-02-17

    China has invested heavily on alternative energy, but the effectiveness of such energy sources at substituting the dominant coal-fired generation remains unknown. Here we analyse the displacement of fossil-fuel-generated electricity by alternative energy, primarily hydropower, and by trans-provincial imported electricity in China between 1995 and 2014 using two-way fixed-effects panel regression models. Nationwide, each unit of alternative energy displaces nearly one-quarter of a unit of fossil-fuel-generated electricity, while each unit of imported electricity (regardless of the generation source) displaces ∼0.3 unit of fossil-fuel electricity generated locally. Results from the six regional grids indicate that significant displacement of fossil-fuel-generated electricity occurs once the share of alternative energy in the electricity supply mix exceeds ∼10%, which is accompanied by 10-50% rebound in the consumption of fossil-fuel-generated electricity. These findings indicate the need for a policy that integrates carbon taxation, alternative energy and energy efficiency to facilitate China's transition towards a low-carbon economy.

  11. THE MAIN DIRECTIONS OF IMPROVING THE EFFICIENCY OF PRODUCTION, TRANSMISSION AND DISTRIBUTION OF ELECTRICAL ENERGY

    Directory of Open Access Journals (Sweden)

    I. V. Zhezhelenko

    2018-01-01

    Full Text Available The main directions of increase of efficiency of production, transmission and distribution of electric energy have been formulated. The relation between the values of electricity losses during transmission via power grids of different countries and the level of the economies of these countries characterized by the value of gross domestic product at purchasing power parity per capita has been established. In the countries with a gross domestic product at purchasing power parity per capita less than 20 thousand US dollars electricity losses during its transmission via power grids are 1.5–2.5 times more than the ones transmitted via power grids of the industrialized countries where the specified purchasing power parity is in the range of 30.4–54.5 thousand US dollars. In the countries with more developed economies the technical culture of production, transmission and distribution of electricity is higher; the modern control systems of operation modes of electrical networks are used as well as of monitoring and accounting of electricity; also there are solvent and disciplined consumers in such countries as well as clear regulatory framework and tariff regulation system. However, the process of transmission and distribution of electricity is effective if not only low relative losses take place, but the normal (contractual requirements for carrying capacity, quality and reliability of electricity supply are provided. The possibility of analytical determination of the optimum value of reserve capacity of power plants providing the required level of reliability of the power system has been considered.

  12. Displacement efficiency of alternative energy and trans-provincial imported electricity in China

    Science.gov (United States)

    Hu, Yuanan; Cheng, Hefa

    2017-02-01

    China has invested heavily on alternative energy, but the effectiveness of such energy sources at substituting the dominant coal-fired generation remains unknown. Here we analyse the displacement of fossil-fuel-generated electricity by alternative energy, primarily hydropower, and by trans-provincial imported electricity in China between 1995 and 2014 using two-way fixed-effects panel regression models. Nationwide, each unit of alternative energy displaces nearly one-quarter of a unit of fossil-fuel-generated electricity, while each unit of imported electricity (regardless of the generation source) displaces ~0.3 unit of fossil-fuel electricity generated locally. Results from the six regional grids indicate that significant displacement of fossil-fuel-generated electricity occurs once the share of alternative energy in the electricity supply mix exceeds ~10%, which is accompanied by 10-50% rebound in the consumption of fossil-fuel-generated electricity. These findings indicate the need for a policy that integrates carbon taxation, alternative energy and energy efficiency to facilitate China's transition towards a low-carbon economy.

  13. Securing energy efficiency as a high priority. Scenarios for common appliance electricity consumption in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Foran, T. [Unit for Social and Environmental Research USER, Faculty of Social Sciences, Chiang Mai University, P.O. Box 144, Chiang Mai, 50200 (Thailand); Du Pont, P.T. [International Resources Group and Joint Graduate School of Energy and Environment, Bangkok (Thailand); Parinya, P. [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Phumaraphand, N. [Electricity Generating Authority of Thailand, Nonthaburi (Thailand)

    2010-11-15

    Between 1995 and 2008, Thailand's energy efficiency programs produced an estimated total of 8,369 GWh/year energy savings and 1,471 MW avoided peak power. Despite these impressive saving figures, relatively little future scenario analysis is available to policy makers. Before the 2008 global financial crisis, electricity planners forecasted 5-6% long-term increases in demand. We explored options for efficiency improvements in Thailand's residential sector, which consumes more than 20% of Thailand's total electricity consumption of 150 TWh/year. We constructed baseline and efficient scenarios for the period 2006-2026, for air conditioners, refrigerators, fans, rice cookers, and compact fluorescent light bulbs. We drew on an appliance database maintained by Electricity Generating Authority of Thailand's voluntary labeling program. For the five appliances modeled, the efficiency scenario results in total savings of 12% of baseline consumption after 10 years and 29% of baseline after 20 years. Approximately 80% of savings come from more stringent standards for air conditioners, including phasing out unregulated air conditioner sales within 6 years. Shifting appliance efficiency standards to current best-in-market levels within 6 years produces additional savings. We discuss institutional aspects of energy planning in Thailand that thus far have limited the consideration of energy efficiency as a high-priority resource.

  14. Increased electrical efficiency in biofueled CHP plants by biomass drying; Oekat elutbyte i biobraensleeldade kraftvaermeanlaeggningar med hjaelp av foertorkning

    Energy Technology Data Exchange (ETDEWEB)

    Berntsson, Mikael; Thorson, Ola; Wennberg, Olle

    2010-09-15

    In this report, integrated biofuel drying has been studied for two cases. One is the existing CHP plant at ENA Energi AB in Enkoeping and the other is a theoretical case. The thought plant is assumed to have a steam generating performance that is probable for a future CHP plant optimised for power production. The CHP plant at ENA Energi with its integrated bed drying system has been used as a model in this study. The plant has a grate fired boiler with the capacity to co-produce 24 MW electricity and 55 MW heat. It is designed to use biofuel with moisture content between 40 and 55 %. However, the boiler is able to manage even dryer fuels with the moisture content of about 35 % without complications. Since the boiler operates on part load during most of the season, there are free capacity which can be used for delivering heat to the drying system. The increased power production is a result of mainly two factors: Increased demand of heat as the dryer uses district heating and thus improved possibility to produce steam; and, The season of operation can be extended, since the point where the minimum load of the boiler occurs can be pushed forward as a result of increased demand of heat. For future CHP plants, an optimised plant has been used as a model. The steam data is assumed to be 170 bar and 540 deg C with reheating. For this plant, both on-site and offsite drying have been studied. The case study comprises a whole season of operation and the fuel is assumed to be dried from 50 to 10 %. The size of the optimised plant is as to fit the dimension of a main production unit in a district heating net equal to the tenth largest in Sweden. Heat delivery is assumed to be 896 GWh/year and the maximum heat delivery of district heating is 250 MW. The sizing of the boiler is made to maximise the production of electricity, and thus dependent of the drying strategy used. Flue gas condensation is assumed to be used as much as possible. It decreases the basis for power production

  15. Operational electricity transmission rates

    International Nuclear Information System (INIS)

    Roggen, M.

    1997-01-01

    In a liberalized electricity market both the consumers and the producers of electricity must pay for the use of the power transmission network. Thus, the net manager has unlimited options to realize efficiency improvements. A neutral and transparent management of the power grid is necessary to avoid disturbance of the market. KEMA Consulting translated abstract ideas and strategic advices to operational concepts in its report 'A framework for the determination of tariffs of the transport in the Dutch electricity sector'

  16. The Increase of Power Efficiency of Underground Coal Mining by the Forecasting of Electric Power Consumption

    Science.gov (United States)

    Efremenko, Vladimir; Belyaevsky, Roman; Skrebneva, Evgeniya

    2017-11-01

    In article the analysis of electric power consumption and problems of power saving on coal mines are considered. Nowadays the share of conditionally constant costs of electric power for providing safe working conditions underground on coal mines is big. Therefore, the power efficiency of underground coal mining depends on electric power expense of the main technological processes and size of conditionally constant costs. The important direction of increase of power efficiency of coal mining is forecasting of a power consumption and monitoring of electric power expense. One of the main approaches to reducing of electric power costs is increase in accuracy of the enterprise demand in the wholesale electric power market. It is offered to use artificial neural networks to forecasting of day-ahead power consumption with hourly breakdown. At the same time use of neural and indistinct (hybrid) systems on the principles of fuzzy logic, neural networks and genetic algorithms is more preferable. This model allows to do exact short-term forecasts at a small array of input data. A set of the input parameters characterizing mining-and-geological and technological features of the enterprise is offered.

  17. Export orientation and domestic electricity generation: Effects on energy efficiency innovation in select sectors

    International Nuclear Information System (INIS)

    Urpelainen, Johannes

    2011-01-01

    Why are some countries developing many energy efficiency innovations, while others are lagging behind? I argue that export orientation and electricity at low variable cost from nuclear and hydropower plants have an interactive effect on energy efficiency innovation. Export-oriented countries have strong incentives to invest in energy efficiency innovation, as they are in a position to export these technology innovations for global markets. But if inexpensive electricity is supplied in a country, the domestic demand for energy efficiency innovation is missing, and so the home market cannot serve as a springboard for international commercialization. I test this theory against international patent data on energy efficiency innovation in insulation, heating, and lighting for 22 OECD countries, 1991-2007. The statistical analysis indicates that export orientation has large positive effects on energy efficiency innovation in countries that do not rely on nuclear and hydroelectricity. - Highlights: → Export-oriented countries produce energy efficiency innovations. → Nuclear and hydropower reduce energy efficiency innovation. → Data on international patents from industrialized countries support the argument.

  18. Efficiency-improving fossil fuel technologies for electricity generation: Data selection and trends

    Energy Technology Data Exchange (ETDEWEB)

    Lanzi, Elisa [Fondazione Eni Enrico Mattei (Italy); Verdolini, Elena, E-mail: elena.verdolini@feem.it [Fondazione Eni Enrico Mattei (Italy); Universita Cattolica, del Sacro Cuore di Milano (Italy); Hascic, Ivan [OECD Environment Directorate (France)

    2011-11-15

    This paper studies patenting dynamics in efficiency improving electricity generation technologies as an important indicator of innovation activity. We build a novel database of worldwide patent applications in efficiency-improving fossil fuel technologies for electricity generation and then analyse patenting trends over time and across countries. We find that patenting has mostly been stable over time, with a recent decreasing trend. OECD countries represent the top innovators and the top markets for technology. Some non-OECD countries, and particularly China, are also very active in terms of patenting activity in this sector. The majority of patents are first filed in OECD countries and only then in BRIC and other non-OECD countries. BRIC and other non-OECD countries apply for patents that are mostly marketed domestically, but BRIC countries represent important markets for patent duplication of OECD inventions. These results are indicative of significant technology transfer in the field of efficiency-improving technologies for electricity production. - Highlights: > We study innovation in efficiency-improving electricity generation technologies. > Relevant patents are identified and used as an indicator of innovation. > We show that there is significant technology transfer in this field. > Most patents are first filed in OECD countries and then in non-OECD countries. > Patents in non-OECD countries are mostly marketed domestically.

  19. An efficiency improved single-phase PFC converter for electric vehicle charger applications

    DEFF Research Database (Denmark)

    Zhu, Dexuan; Tang, Yi; Jin, Chi

    2013-01-01

    This paper presents an efficiency improved single-phase power factor correction (PFC) converter with its target application to plug-in hybrid electric vehicle (PHEV) charging systems. The proposed PFC converter features sinusoidal input current, three-level output characteristic, and wide range...

  20. Radical production efficiency and electrical characteristics of a coplanar barrier discharge built by multilayer ceramic technology

    DEFF Research Database (Denmark)

    Jõgi, Indrek; Erme, Kalev; Levoll, Erik

    2017-01-01

    The present study investigated the electrical characteristics and radical production efficiency of a coplanar barrier discharge (CBD) device manufactured by Kyocera by multilayer ceramic technology. The device consisted of a number of linear electrodes with electrode and gap widths of 0.75 mm...

  1. The role of energy and investment literacy for residential electricity demand and end-use efficiency

    NARCIS (Netherlands)

    Blasch, J.E.; Boogen, Nina; Filippini, Massimo; Kumar, Nilkanth

    2017-01-01

    This paper estimates the level of transient and persistent efficiency in the use of electricity in Swiss households using the newly developed generalized true random effects model (GTREM). An unbalanced panel dataset of 1, 994 Swiss households from 2010 to 2014 collected via a household survey is

  2. A high-efficiency electrically-pumped single-photon source based on a photonics nanowire

    DEFF Research Database (Denmark)

    Gregersen, Niels; Nielsen, Torben Roland; Mørk, Jesper

    An electrically-pumped single-photon source design with a predicted efficiency of 89% is proposed. The design is based on a quantum dot embedded in a photonic nanowire with tailored ends and optimized contact electrodes. Unlike cavity-based approaches, the photonic nanowire features broadband...

  3. High-efficiency electric motors: An analysis of a feasible tariff policy for Brazil

    International Nuclear Information System (INIS)

    Paiva Delgado, M.A. de; Tolmasquim, M.T.

    1997-01-01

    The main objective is to calculate an average value for an electricity tariff which will facilitate the introduction of high-efficiency electric motors in the production sector. Two computational models will be developed for technical-economic evaluation to assess economic attractiveness by calculating feasible average electricity tariffs in order to create a market for substitution of standard motors by new high-efficiency models (Purchase Decision Model) as well as to determine if retrofitting of standard installed motors by others with high-efficiency characteristics is viable, and, if so, to specify the optimum timing for such substitution (Substitution Decision Model). It should be noted that the Purchase Decision Model takes into account power factor adjustment and the Substitution Decision Model incorporates considerations as to reduction in the electromechanical performance of operating motors. Results indicate that even where average electricity tariffs are low, as in Brazil, high-efficiency motors are economically attractive compared to standard motors. There is an obvious need for complementary instruments to assist massive market penetration

  4. Power to the Plug: An Introduction to Energy, Electricity, Consumption and Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    DOE / EERE / NEED Project

    2011-06-07

    The NEED Project and the U.S. Department of Energy have collaborated to bring you this educational four-page guide to energy, electricity, consumption and efficiency. It includes, on the last page, a home energy survey to help you analyze your home energy use.

  5. Efficiency-improving fossil fuel technologies for electricity generation: Data selection and trends

    International Nuclear Information System (INIS)

    Lanzi, Elisa; Verdolini, Elena; Hascic, Ivan

    2011-01-01

    This paper studies patenting dynamics in efficiency improving electricity generation technologies as an important indicator of innovation activity. We build a novel database of worldwide patent applications in efficiency-improving fossil fuel technologies for electricity generation and then analyse patenting trends over time and across countries. We find that patenting has mostly been stable over time, with a recent decreasing trend. OECD countries represent the top innovators and the top markets for technology. Some non-OECD countries, and particularly China, are also very active in terms of patenting activity in this sector. The majority of patents are first filed in OECD countries and only then in BRIC and other non-OECD countries. BRIC and other non-OECD countries apply for patents that are mostly marketed domestically, but BRIC countries represent important markets for patent duplication of OECD inventions. These results are indicative of significant technology transfer in the field of efficiency-improving technologies for electricity production. - Highlights: → We study innovation in efficiency-improving electricity generation technologies. → Relevant patents are identified and used as an indicator of innovation. → We show that there is significant technology transfer in this field. → Most patents are first filed in OECD countries and then in non-OECD countries. → Patents in non-OECD countries are mostly marketed domestically.

  6. Electricity savings from implementation of minimum energy efficiency standard for TVs in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Varman, M.; Masjuki, H.H.; Mahlia, T.M.I. [University of Malaya, Kuala Lumpur (Malaysia). Department of Mechanical Engineering

    2005-06-01

    The popularization of 24 h pay-TV, interactive video games, web-TV, VCD and DVD in Malaysia are poised to have a large impact on overall TV electricity consumption in the country. With the increasing of overall TV energy consumption, energy efficiency standards are one of highly effective policies for decreasing electricity consumption in the residential sector. Energy efficiency standards are also capable of reducing consumer's electricity bill and contribute towards positive environmental impacts. This paper attempts to predict the amount of energy that can be saved in the residential sector by implementing minimum energy efficiency standard for television sets in Malaysia. Over the past 30 years, television ownership in Malaysian residents has increased from 186,036 units in 1970 to 2,741,640 units in 1991. This figure is expected to reach 6,201,316 units in the year 2010. Hence, efficiency improvement for this appliance will have a significant impact on the future of electricity consumption in this country. (author)

  7. Energy efficiency to reduce residential electricity and natural gas use under climate change.

    Science.gov (United States)

    Reyna, Janet L; Chester, Mikhail V

    2017-05-15

    Climate change could significantly affect consumer demand for energy in buildings, as changing temperatures may alter heating and cooling loads. Warming climates could also lead to the increased adoption and use of cooling technologies in buildings. We assess residential electricity and natural gas demand in Los Angeles, California under multiple climate change projections and investigate the potential for energy efficiency to offset increased demand. We calibrate residential energy use against metered data, accounting for differences in building materials and appliances. Under temperature increases, we find that without policy intervention, residential electricity demand could increase by as much as 41-87% between 2020 and 2060. However, aggressive policies aimed at upgrading heating/cooling systems and appliances could result in electricity use increases as low as 28%, potentially avoiding the installation of new generation capacity. We therefore recommend aggressive energy efficiency, in combination with low-carbon generation sources, to offset projected increases in residential energy demand.

  8. Industry agreement on efficient electrical motors; Industrievereinbarung im Effizienzbereich Motoren (eff1, eff2, eff3)

    Energy Technology Data Exchange (ETDEWEB)

    Schnyder, G. [Schnyder Ingenieure AG, Huenenberg (Switzerland)

    2004-07-01

    This comprehensive final report presents the results of a project carried out on behalf of the Swiss Federal Office of Energy (SFOE) and the Swiss Automation Pool (SAP) concerning the efficiency of electrical drives. The main goal of the project was to conclude a target agreement between the federal government and the Swiss electric motors/drives industry. This involves the promotion of the highest, 'eff1' energy-efficiency category of the three categories defined by the European Committee of Manufacturers of Electrical Machines and Power Electronics (CEMP). The report presents the findings of the project and recommends the banning of the use of motors in the lowest, 'eff3' category. Comparisons are made between the CEMP standards and further standards and promotion programmes in the USA and in Great Britain. Associated measures to be taken to aid the promotion of the drive standard are discussed.

  9. How to increase the efficiency of the electrical discharge method for destruction of nonconductive solid materials

    Energy Technology Data Exchange (ETDEWEB)

    Voitenko, N. V., E-mail: tevn@hvd.tpu.ru; Yudin, A. S.; Kuznetsova, N. S. [National Research Tomsk Polytechnic University (Russian Federation); Krastelev, E. G. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2016-12-15

    The paper deals with the relevance of using electrical discharge technology for construction works in the city. The technical capabilities of the installation for the multi-borehole electro-discharge splitting off and destruction of rocks and concrete are described. The ways to increase the efficiency of the electrical discharge method for the destruction of solids are proposed. In order to augment the discharge circuit energy, the energy storage is separated into two individual capacitor batteries. The throttle with the inductance of 28.6 μH is installed in one of the batteries, which increases the duration of the channel energy release to 400 μs and the efficiency of electrical discharge splitting off of concrete.

  10. The Private Net Benefits of Residential Solar PV: The Role of Electricity Tariffs, Tax Incentives and Rebates

    OpenAIRE

    Severin Borenstein

    2015-01-01

    With dramatic declines in the cost of solar PV technology over the last 5 years, the electricity industry is in the midst of discussions about whether to use this low-polluting renewable energy source in grid-scale generation or in distributed generation (DG), mostly with rooftop solar PV. California has led the growth in DG solar in the U.S. I use 2007 to early 2014 residential data from Pacific Gas & Electric – the utility with largest number of residential solar customers in the U.S. – to ...

  11. Efficient Use of Behavioral Tools to Reduce Electricity Demand of Domestic Consumers

    Directory of Open Access Journals (Sweden)

    Elbaz Shimon

    2016-12-01

    Full Text Available Purpose: The present study investigated the main literature on the subject of methods and policies for reducing the electricity demand of domestic consumers, in order to identify the place of behavioral tools. Methodology: We used secondary sources, performing a literature review, together with analysis and synthesis. Findings: Policy makers prefer to use tools offered by neoclassical economics, such as various forms of taxation, fines and financial incentives in order to make domestic electricity consumers save electricity, on the assumption that consumers will make rational decisions while maximizing their personal benefit. However, studies conducted in recent years in the field of behavioral economics, which are based on the assumption that consumers’ decisions are not rational and are affected by cognitive biases, showed that the use of behavioral tools, such as detailed online information (feedback,social comparison information, information on varying rates (dynamic pricing and general information (advertising campaign, are tools that are not less appropriate than the ones the neoclassical economics offers, mainly because electricity is an invisible product and consumers are unable to assess it by normal cognitive measures. Using an interdisciplinary combination of behavioral tools that come from a variety of approaches taken from a wide variety of different academic fields, it is possible to receive efficient results in the endeavor of reducing electricity demand. Implications: Although the neoclassical economics still remains the fundamental theory used by policymakers, it is recommended to consider behavioral economics as a complementary approach to the neoclassical economics, and combine behavioral tools in the policymakers’ toolbox, especially when those tools do not require a significant financial investment, thus efficiently maximizing the reduction of electricity demand among domestic consumers. These theoretical results will be

  12. Nuclear power plants electrical retrofitting for cost effectiveness, reliability and operating efficiency

    International Nuclear Information System (INIS)

    Ciufu, L.; Popescu, M. O.

    2016-01-01

    In the context of continuous fast growing of the energy demand the current power plants retrofitting concept may represent an important step in the emission reduction, being able to offer in the same time a maximum operating efficiency. This desideratum can be obtained by implementing a rigorous energy management plan, based on an increased energy production capacity of non-pollutant electrical power plants and future-oriented frame on extending their lifetime operation. This management is focused on using state-of-art electronic, electrical and industrial control equipments, which can represent a real key factor. Thus, in this paper an analysis of the electrical system retrofitting is presented. As a part of this research the authors propose and simulate ambitious ways to upgrade actual control and command of the electrical operating systems, by promoting variable speed for large pumps and also computer software, as SCADA, for an intelligent control and monitoring of these studied processes. (authors)

  13. Residual stress evaluation by Barkhausen signals with a magnetic field sensor for high efficiency electrical motors

    Science.gov (United States)

    Tsuchida, Yuji; Enokizono, Masato

    2018-04-01

    The iron loss of industrial motors increases by residual stress during manufacturing processes. It is very important to make clear the distribution of the residual stress in the motor cores to reduce the iron loss in the motors. Barkhausen signals which occur on electrical steel sheets can be used for the evaluation of the residual stress because they are very sensitive to the material properties. Generally, a B-sensor is used to measure Barkhausen signals, however, we developed a new H-sensor to measure them and applied it into the stress evaluation. It is supposed that the Barkhausen signals by using a H-sensor can be much effective to the residual stress on the electrical steel sheets by referring our results regarding to the stress evaluations. We evaluated the tensile stress of the electrical steel sheets by measuring Barkhausen signals by using our developed H-sensor for high efficiency electrical motors.

  14. Semiconductors enable efficient solutions in electric vehicles; Halbleiter ermoeglichen effiziente Loesungen in Elektrofahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Adlkofer, Hans [Infineon Technologies AG, Muenchen (Germany)

    2010-07-01

    The automotive industry currently enters a new phase of the competition. The successful addressing of vehicles with electric motors is in the focus of he competition. Electric vehicles which save the electrical energy in batteries may not replace immediately all fuel-powered vehicles in the given transport infrastructure. The semiconductor industry needs to provide solutions and technologies in order to increase the efficiency of electric vehicles and further to reduce the operating costs. Thus, the author of the contribution under consideration reports on possible ways to this target using a battery balancing system considering the amortization of such a system. The presented active battery cell management system may monitor the charging and discharging of the battery by means of a software monitor so that an energy recovery system is supported optimally. It ensures a reliable operation, prevents accidental premature battery failure and enables cost savings of about 10 % for the whole set of batteries.

  15. Net energy benefits of carbon nanotube applications

    International Nuclear Information System (INIS)

    Zhai, Pei; Isaacs, Jacqueline A.; Eckelman, Matthew J.

    2016-01-01

    Highlights: • Life cycle net energy benefits are examined. • CNT-enabled and the conventional technologies are compared. • Flash memory with CNT switches show significant positive net energy benefit. • Lithium-ion batteries with MWCNT cathodes show positive net energy benefit. • Lithium-ion batteries with SWCNT anodes tend to exhibit negative net energy benefit. - Abstract: Implementation of carbon nanotubes (CNTs) in various applications can reduce material and energy requirements of products, resulting in energy savings. However, processes for the production of carbon nanotubes (CNTs) are energy-intensive and can require extensive purification. In this study, we investigate the net energy benefits of three CNT-enabled technologies: multi-walled CNT (MWCNT) reinforced cement used as highway construction material, single-walled CNT (SWCNT) flash memory switches used in cell phones and CNT anodes and cathodes used in lithium-ion batteries used in electric vehicles. We explore the avoided or additional energy requirement in the manufacturing and use phases and estimate the life cycle net energy benefits for each application. Additional scenario analysis and Monte Carlo simulation of parameter uncertainties resulted in probability distributions of net energy benefits, indicating that net energy benefits are dependent on the application with confidence intervals straddling the breakeven line in some cases. Analysis of simulation results reveals that SWCNT switch flash memory and MWCNT Li-ion battery cathodes have statistically significant positive net energy benefits (α = 0.05) and SWCNT Li-ion battery anodes tend to have negative net energy benefits, while positive results for MWCNT-reinforced cement were significant only under an efficient CNT production scenario and a lower confidence level (α = 0.1).

  16. Toward Highly Efficient Nanostructured Solar Cells Using Concurrent Electrical and Optical Design

    KAUST Repository

    Wang, Hsin-Ping

    2017-07-11

    Recent technological advances in conventional planar and microstructured solar cell architectures have significantly boosted the efficiencies of these devices near the corresponding theoretical values. Nanomaterials and nanostructures have promising potential to push the theoretical limits of solar cell efficiency even higher using the intrinsic advantages associated with these materials, including efficient photon management, rapid charge transfer, and short charge collection distances. However, at present the efficiency of nanostructured solar cells remains lower than that of conventional solar devices due to the accompanying losses associated with the employment of nanomaterials. The concurrent design of both optical and electrical components will presumably be an imperative route toward breaking the present-day limit of nanostructured solar cells. This review summarizes the losses in traditional solar cells, and then discusses recent advances in applications of nanotechnology to solar devices from both optical and electrical perspectives. Finally, a rule for nanostructured solar cells by concurrently engineering the optical and electrical design is devised. Following these guidelines should allow for exceeding the theoretical limit of solar cell efficiency soon.

  17. Dossier high-efficient electric water heater. Electricity by a Stirling engine; Het Dossier HRE-ketel. Stroom uit Stirlingmotor

    Energy Technology Data Exchange (ETDEWEB)

    Scholtens, B.

    2010-10-15

    The market seems ready for a private power plant on the wall in the attic, which also heats the house. Such an installation is the successor of the high efficiency boiler, which is in use in most of the homes in the Netherlands. After fifteen years of development Dutch companies have taken the lead in this technology. The manufacturer Remeha in Apeldoorn, Netherlands, started one month ago with the production of high efficiency electric boiler. [Dutch] De markt lijkt klaar voor een eigen stroomcentrale aan de muur op zolder die bovendien het huis verwarmt. De installatie is de opvolger van de hoogrendementsketel, die de meeste huizen in Nederland verwarmt. Na vijftien jaar ontwikkeling hebben Nederlandse bedrijven het technologische voortouw genomen. De Apeldoornse fabrikant Remeha is een maand geleden als eerste met serieproductie van de hre-ketel begonnen.

  18. Data on electrical energy conservation using high efficiency motors for the confidence bounds using statistical techniques.

    Science.gov (United States)

    Shaikh, Muhammad Mujtaba; Memon, Abdul Jabbar; Hussain, Manzoor

    2016-09-01

    In this article, we describe details of the data used in the research paper "Confidence bounds for energy conservation in electric motors: An economical solution using statistical techniques" [1]. The data presented in this paper is intended to show benefits of high efficiency electric motors over the standard efficiency motors of similar rating in the industrial sector of Pakistan. We explain how the data was collected and then processed by means of formulas to show cost effectiveness of energy efficient motors in terms of three important parameters: annual energy saving, cost saving and payback periods. This data can be further used to construct confidence bounds for the parameters using statistical techniques as described in [1].

  19. Projected electricity savings from implementing minimum energy efficiency standard for household refrigerators in Malaysia

    International Nuclear Information System (INIS)

    Mahlia, T.M.I.; Masjuki, H.H.; Saidur, R.; Choudhury, I.A.; NoorLeha, A.R.

    2003-01-01

    The Malaysian economy has grown rapidly in the last two decades. This growth has increased the ownership of household electrical appliances, especially refrigerator-freezers. Almost every house in Malaysia owns a refrigerator-freezer. The Malaysia Energy Center considered implementing a minimum energy efficiency standard for household refrigerator-freezers sometime in the coming year. This paper attempts to predict the amount of energy savings in the residential sector by implementing a minimum energy efficiency standard for household refrigerator-freezers. The calculations are based on the growth of refrigerator-freezer ownership data in Malaysian households. By implementing the programs in 2004, about 8722 GWh will be saved in the year 2013. Therefore, efficiency improvement of this appliance will provide a significant impact in future electricity consumption in Malaysia

  20. The barriers to energy efficiency in China: Assessing household electricity savings and consumer behavior in Liaoning Province

    International Nuclear Information System (INIS)

    Feng Dianshu; Sovacool, Benjamin K.; Khuong Minh Vu

    2010-01-01

    This article investigates the barriers to energy efficiency at the residential sector within one province in China and explores patterns of household electricity consumption. The article presents the results of a survey questionnaire distributed to more than 600 households in Liaoning Province, field research at various Liaoning government agencies, and research interviews of Liaoning government officials to determine the efficacy of their energy efficiency efforts in China. It then investigates the extent that electricity consumers have taken advantage of energy efficiency opportunities relating to more efficient lights, water heaters, appliances, air-conditioners and heaters, and better energy-efficiency labels. The article also assesses the degree that electricity users have become more aware about electricity prices and their levels of consumption, and touches on the connection between rising levels of income and electricity use. It concludes by providing recommendations for how to improve efforts to promote conservation and reduce electricity load growth in Liaoning Province and beyond.

  1. The barriers to energy efficiency in China. Assessing household electricity savings and consumer behavior in Liaoning Province

    Energy Technology Data Exchange (ETDEWEB)

    Dianshu, Feng; Sovacool, Benjamin K.; Minh Vu, Khuong [Lee Kuan Yew School of Public Policy, Centre on Asia and Globalisation, National University of Singapore, Oei Tiong Ham Building, 469C Bukit Timah Road, Singapore 259772 (Singapore)

    2010-02-15

    This article investigates the barriers to energy efficiency at the residential sector within one province in China and explores patterns of household electricity consumption. The article presents the results of a survey questionnaire distributed to more than 600 households in Liaoning Province, field research at various Liaoning government agencies, and research interviews of Liaoning government officials to determine the efficacy of their energy efficiency efforts in China. It then investigates the extent that electricity consumers have taken advantage of energy efficiency opportunities relating to more efficient lights, water heaters, appliances, air-conditioners and heaters, and better energy-efficiency labels. The article also assesses the degree that electricity users have become more aware about electricity prices and their levels of consumption, and touches on the connection between rising levels of income and electricity use. It concludes by providing recommendations for how to improve efforts to promote conservation and reduce electricity load growth in Liaoning Province and beyond. (author)

  2. The barriers to energy efficiency in China: Assessing household electricity savings and consumer behavior in Liaoning Province

    Energy Technology Data Exchange (ETDEWEB)

    Feng Dianshu, E-mail: dianshu@nus.edu.s [Lee Kuan Yew School of Public Policy, Centre on Asia and Globalisation, National University of Singapore, Oei Tiong Ham Building, 469C Bukit Timah Road, Singapore 259772 (Singapore); Sovacool, Benjamin K., E-mail: bsovacool@nus.edu.s [Lee Kuan Yew School of Public Policy, Centre on Asia and Globalisation, National University of Singapore, Oei Tiong Ham Building, 469C Bukit Timah Road, Singapore 259772 (Singapore); Khuong Minh Vu, E-mail: sppkmv@nus.edu.s [Lee Kuan Yew School of Public Policy, Centre on Asia and Globalisation, National University of Singapore, Oei Tiong Ham Building, 469C Bukit Timah Road, Singapore 259772 (Singapore)

    2010-02-15

    This article investigates the barriers to energy efficiency at the residential sector within one province in China and explores patterns of household electricity consumption. The article presents the results of a survey questionnaire distributed to more than 600 households in Liaoning Province, field research at various Liaoning government agencies, and research interviews of Liaoning government officials to determine the efficacy of their energy efficiency efforts in China. It then investigates the extent that electricity consumers have taken advantage of energy efficiency opportunities relating to more efficient lights, water heaters, appliances, air-conditioners and heaters, and better energy-efficiency labels. The article also assesses the degree that electricity users have become more aware about electricity prices and their levels of consumption, and touches on the connection between rising levels of income and electricity use. It concludes by providing recommendations for how to improve efforts to promote conservation and reduce electricity load growth in Liaoning Province and beyond.

  3. Study on the effect of driving cycles on energy efficiency of electric vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Ji Fenzhu; Xu Licong [School of Transportation Science and Engineering of Beihang Univ., BJ (China); Wu Zhixin [Tianjin Qing Yuan Electric Vehicle Corp. Ltd., TJ (China)

    2009-07-01

    The energy usage efficiency of electric vehicles (EVS) and evaluation index of electromotor efficiency were studied. The idea of ''interval usage percentage of energy efficiency'' and ''exertion degree of energy efficiency'' of electromotor was brought forward. The effect of driving cycles on the distribution of running status of electromotor and its efficiency was investigated. The electromotor efficiency and the variety trend of average driving force at different driving cycles were discussed. Based on several typical domestic and foreign driving cycles, the exertion degree of energy efficiency and the whole efficiency of power train on some types of EVS were analyzed and calculated. The result indicates that there is a difference of 9.64% in exertion degree of energy efficiency of electromotor at different driving cycles. The efficiency distribution of electromotor and control system is different, and the average driving force is different, too. That cause the great variety in driving range. The idiographic reference data are provided to the establishment of driving cycles' criterion of EVS in our country. (orig.)

  4. Approach to Hybrid Energy Storage Systems Dimensioning for Urban Electric Buses Regarding Efficiency and Battery Aging

    Directory of Open Access Journals (Sweden)

    Jorge Nájera

    2017-10-01

    Full Text Available This paper focuses on Hybrid Energy Storage Systems (HESS, consisting of a combination of batteries and Electric Double Layer Capacitors (EDLC, for electric urban busses. The aim of the paper is to develop a methodology to determine the hybridization percentage that allows the electric bus to work with the highest efficiency while reducing battery aging, depending on the chosen topology, control strategy, and driving cycle. Three power electronic topologies are qualitatively analyzed based on different criteria, with the topology selected as the favorite being analyzed in detail. The whole system under study is comprised of the following elements: a battery pack (LiFePO4 batteries, an EDLC pack, up to two DC-DC converters (depending on the topology, and an equivalent load, which behaves as an electric bus drive (including motion resistances and inertia. Mathematical models for the battery, EDLCs, DC-DC converter, and the vehicle itself are developed for this analysis. The methodology presented in this work, as the main scientific contribution, considers performance variation (energy efficiency and battery aging and hybridization percentage (ratio between batteries and EDLCs, defined in terms of mass, using a power load profile based on standard driving cycles. The results state that there is a hybridization percentage that increases energy efficiency and reduces battery aging, maximizing the economic benefits of the vehicle, for every combination of topology, type of storage device, control strategy, and driving cycle.

  5. Analysis of downshift’s improvement to energy efficiency of an electric vehicle during regenerative braking

    International Nuclear Information System (INIS)

    Li, Liang; Li, Xujian; Wang, Xiangyu; Song, Jian; He, Kai; Li, Chenfeng

    2016-01-01

    Highlights: • Downshift is effective in improving the energy efficiency of electric vehicles. • Energy improvement of downshift varies with vehicle speed and brake strength. • The designed nonlinear sliding mode observer is accurate in estimating bake torque. • The proposed resembling PWM method is practical to regulate hydraulic pressure. • The effect of downshift on braking safety and comfort can be restrained by control. - Abstract: Downshift during regenerative braking helps to improve the energy efficiency of electric vehicles. Two main problems are involved in the downshift process. One is the determination of optimal downshift point, and the other is the cooperative control of regenerative braking and hydraulic braking. In order to achieve a systemic solution to these problems, a hierarchical control strategy is brought forward for an electric vehicle with a two-speed automated mechanical transmission. For the upper controller, an off-line calculation and on-line look-up table method is adopted to obtain the optimal downshift point, and a series regenerative braking distribution strategy is designed. For the medium controller, a nonlinear sliding mode observer is designed to obtain the actual hydraulic brake torque. For the lower controller, cooperative control of regenerative braking and hydraulic braking is given to ensure brake safety during downshift process, and a resembling pulse width modulation method is proposed to regulated the hydraulic brake torque. Simulation results and hardware-in-loop test show that the proposed algorithm is effective in improving the energy efficiency of electric vehicles.

  6. Examining demand response, renewable energy and efficiencies to meet growing electricity needs

    International Nuclear Information System (INIS)

    Elliot, N.; Eldridge, M.; Shipley, A.M.; Laitner, J.S.; Nadel, S.; Silverstein, A.; Hedman, B.; Sloan, M.

    2007-01-01

    While Texas has already taken steps to improve its renewable energy portfolio (RPS), and its energy efficiency improvement program (EEIP), the level of savings that utilities can achieve through the EEIP can be greatly increased. This report estimated the size of energy efficiency and renewable energy resources in Texas, and suggested a range of policy options that might be adopted to further extend EEIP. Current forecasts suggest that peak demand in Texas will increase by 2.3 per cent annually from 2007-2012, a level of growth which is threatening the state's ability to maintain grid reliability at reasonable cost. Almost 70 per cent of installed generating capacity is fuelled by natural gas in Texas. Recent polling has suggested that over 70 per cent of Texans are willing support increased spending on energy efficiency. Demand response measures that may be implemented in the state include incentive-based programs that pay users to reduce their electricity consumption during specific times and pricing programs, where customers are given a price signal and are expected to moderate their electricity usage. By 2023, the widespread availability of time-varying retail electric rates and complementary communications and control methods will permanently change the nature of electricity demand in the state. At present, the integrated utilities in Texas offer a variety of direct load control and time-of-use, curtailable, and interruptible rates. However, with the advent of retail competition now available as a result of the structural unbundling of investor-owned utilities, there is less demand response available in Texas. It was concluded that energy efficiency, demand response, and renewable energy resources can meet the increasing demand for electricity in Texas over the next 15 years. 4 figs

  7. Petri Nets

    Indian Academy of Sciences (India)

    In a computer system, for example, typical discrete events ... This project brought out a series of influential reports on Petri net theory in the mid and late ... Technology became a leading centre for Petri net research and from then on, Petri nets ...

  8. Efficiency in the United States electric industry: Transaction costs, deregulation, and governance structures

    Science.gov (United States)

    Peterson, Carl

    Transaction costs economics (TCE) posits that firms have an incentive to bypass the market mechanisms in situations where the cost of using the market is prohibitive. Vertical integration, among other governance mechanisms, can be used to minimize the transactions costs associated with the market mechanism. The study analyses different governance mechanisms, which range from complete vertical integration to the use of market mechanisms, for firms in the US electric sector. This sector has undergone tremendous change in the past decade including the introduction of retail competition in some jurisdictions. As a result of the push toward deregulation of the industry, vertically integration, while still significant in the sector, has steadily been replaced by alternative governance structures. Using a sample of 136 investor-owned electric utilities that reported data the US Federal Energy Regulatory Commission between 1996 and 2002, this study estimates firm level efficiency using Data Envelopment Analysis (DEA) and relates these estimates to governance structure and public policies. The analysis finds that vertical integration is positively related to firm efficiency, although in a non-linear fashion suggesting that hybrid governance structures tend to be associated with lower efficiency scores. In addition, while some evidence is found for negative short-term effects on firm efficiency from the choice to deregulate, this result is sensitive to DEA model choice. Further, competition in retail markets is found to be positively related to firm level efficiency, but the retreat from deregulation, which occurred after 2000, is negatively associated with firm-level efficiency. These results are important in the ongoing academic and public policy debates concerning deregulation of the electric section and indicate that vertical economies remain in the industry, but that competition has provided incentives for improving firm level efficiency.

  9. Energy conversion efficiency of hybrid electric heavy-duty vehicles operating according to diverse drive cycles

    Energy Technology Data Exchange (ETDEWEB)

    Banjac, Titina [AVL-AST d.o.o., Trg Leona Stuklja 5, SI-2000 Maribor (Slovenia); Trenc, Ferdinand; Katrasnik, Tomaz [Faculty of Mechanical Engineering, Univ. of Ljubljana, Askerceva 6, SI-1000 Ljubljana (Slovenia)

    2009-12-15

    Energy consumption and exhaust emissions of hybrid electric vehicles (HEVs) strongly depend on the HEV topology, power ratios of their components and applied control strategy. Combined analytical and simulation approach was applied to analyze energy conversion efficiency of different HEV topologies. Analytical approach is based on the energy balance equations and considers all energy paths in the HEVs from the energy sources to the wheels and to other energy sinks. Simulation approach is based on a fast forward-facing simulation model for simulating parallel and series HEVs as well as for conventional internal combustion engine vehicles, and considers all components relevant for modeling energy conversion phenomena. Combined approach enables evaluation of energy losses on different energy paths and provides their impact on the fuel economy. It therefore enables identification of most suitable HEV topology and of most suitable power ratios of the components for targeted vehicle application, since it reveals and quantifies the mechanisms that could lead to improved energy conversion efficiency of particular HEV. The paper exposes characteristics of the test cycles that lead to improved energy conversion efficiency of HEVs. Mechanisms leading to improved fuel economy of parallel HEVs through drive-away and vehicle propulsion at low powertrain loads by electric motor are also analyzed. It was also shown that control strategies managing energy flow through electric storage devices significantly influence energy conversion efficiency of series HEVs. (author)

  10. Improving Thermal and Electrical Efficiency in Photovoltaic Thermal Systems for Sustainable Cooling System Integration

    Directory of Open Access Journals (Sweden)

    Mohammad Alobaid

    2018-06-01

    Full Text Available Research into photovoltaic thermal systems is important in solar technologies as photovoltaic thermal systems are designed to produce both electrical and thermal energy, this can lead to improved performance of the overall system. The performance of photovoltaic thermal systems is based on several factors that include photovoltaic thermal materials, design, ambient temperature, inlet and outlet fluid temperature and photovoltaic cell temperature. The aim of this study is to investigate the effect of photovoltaic thermal outlet water temperatures and solar cell temperature on both electrical and thermal efficiency for different range of inlet water temperature. To achieve this, a mathematical model of a photovoltaic thermal system was developed to calculate the anticipated system performance. The factors that affect the efficiency of photovoltaic thermal collectors were discussed and the outlet fluid temperature from the photovoltaic thermal is investigated in order to reach the highest overall efficiency for the solar cooling system. An average thermal and electrical efficiency of 65% and 13.7%, respectively, was achieved and the photovoltaic thermal mathematical model was validated with experimental data from literature.

  11. Biomass gasification for electricity generation with internal combustion engines. Process efficiency

    International Nuclear Information System (INIS)

    Lesme-Jaén, René; Garcia Faure, Luis; Recio Recio, Angel; Oliva Ruiz, Luis; Pajarín Rodríguez, Juan; Revilla Suarez, Dennis

    2015-01-01

    Biomass is a renewable source of energy worldwide increased prospects for its potential and its lower environmental impact compared to fossil fuels. By processes and energy conversion technologies it is possible to obtain fuels in solid, liquid and gaseous form from any biomass. The biomass gasification is the thermal conversion thereof into a gas, which can be used for electricity production with the use of internal combustion engines with a certain level of efficiency, which depends on the characteristics of biomass and engines used. In this work the evaluation of thermal and overall efficiency of the gasification in Integrated Forestry Enterprise of Santiago de Cuba, designed to generate electricity from waste from the forest industry is presented. Is a downdraft gasifier reactor, COMBO-80 model and engine manufacturing Hindu (diesel) model Leyland modified to work with producer gas. The evaluation was carried out for different loads (electric power generated) engine from experimental measurements of flow and composition of the gas supplied to the engine. The results show that the motor operates with a thermal efficiency in the range of 20-32% with an overall efficiency between 12-25%. (full text)

  12. Evaluating Interventions in the U.S. Electricity System: Assessments of Energy Efficiency, Renewable Energy, and Small-Scale Cogeneration

    Science.gov (United States)

    Siler-Evans, Kyle

    to evaluate the effects of an additional wind turbine or solar panel in the U.S. electricity system. I find that the most attractive sites for renewables depend strongly on one's objective. A solar panel in Iowa displaces 20% more CO2 emissions than a panel in Arizona, though energy production from the Iowa panel is 25% less. Similarly, despite a modest wind resource, a wind turbine in West Virginia is expected to displace 7 times more health and environmental damages than a wind turbine in Oklahoma. Finally, I shift focus and explore the economics of small-scale cogeneration, which has long been recognized as a more efficient alternative to central-station power. Although the benefits of distributed cogeneration are widely cited, adoption has been slow in the U.S. Adoption could be encouraged by making cogeneration more economically attractive, either by increasing the expected returns or decreasing the risks of such investments. I present a case study of a 300-kilowatt cogeneration unit and evaluate the expected returns from: demand response, capacity markets, regulation markets, accelerated depreciation, a price on CO2 emissions, and net metering. In addition, I explore the effectiveness of feed-in tariffs at mitigating the energy-price risks to cogeneration projects.

  13. Achieving Very High Efficiency and Net Zero Energy in an Existing Home in a Hot-Humid Climate. Long-Term Utility and Monitoring Data

    Energy Technology Data Exchange (ETDEWEB)

    Parker, D. [BA-PIRC/ Florida Solar Energy Center, Cocoa, FL (United States); Sherwin, J. [BA-PIRC/ Florida Solar Energy Center, Cocoa, FL (United States)

    2012-10-01

    This study summarizes the first six months of detailed data collected on a single family home that experienced a series of retrofits targeting reductions in energy use. The project was designed to develop data on how envelope modifications and renewable measures can result in considerable energy reductions and potentially net zero energy for an existing home. Originally published in February 2012, this revised version of the report contains further research conducted on the Parker residence. Key updates include one full year of additional data, an analysis of cooling performance of the mini-split heat pump, an evaluation of room-to-room temperature distribution, and an evaluation of plug-in automobile charging performance, electricity consumption, and load shape.

  14. Achieving Very High Efficiency and Net Zero Energy in an Existing Home in a Hot-Humid Climate: Long-Term Utility and Monitoring Data (Revised)

    Energy Technology Data Exchange (ETDEWEB)

    Parker, D.; Sherwin, J.

    2012-10-01

    This study summarizes the first six months of detailed data collected on a single family home that experienced a series of retrofits targeting reductions in energy use. The project was designed to develop data on how envelope modifications and renewable measures can result in considerable energy reductions and potentially net zero energy for an existing home. Originally published in February 2012, this revised version of the report contains further research conducted on the Parker residence. Key updates include one full year of additional data, an analysis of cooling performance of the mini-split heat pump, an evaluation of room-to-room temperature distribution, and an evaluation of plug-in automobile charging performance, electricity consumption, and load shape.

  15. High-efficiency gene transfer into skeletal muscle mediated by electric pulses

    DEFF Research Database (Denmark)

    Mir, L M; Bureau, M F; Gehl, J

    1999-01-01

    Gene delivery to skeletal muscle is a promising strategy for the treatment of muscle disorders and for the systemic secretion of therapeutic proteins. However, present DNA delivery technologies have to be improved with regard to both the level of expression and interindividual variability. We...... report very efficient plasmid DNA transfer in muscle fibers by using square-wave electric pulses of low field strength (less than 300 V/cm) and of long duration (more than 1 ms). Contrary to the electropermeabilization-induced uptake of small molecules into muscle fibers, plasmid DNA has to be present...... in the tissue during the electric pulses, suggesting a direct effect of the electric field on DNA during electrotransfer. This i.m. electrotransfer method increases reporter and therapeutic gene expression by several orders of magnitude in various muscles in mouse, rat, rabbit, and monkey. Moreover, i...

  16. An efficient methodology for the analysis of primary frequency control of electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, D.P. [Nikola Tesla Institute, Belgrade (Yugoslavia); Mijailovic, S.V. [Electricity Coordinating Center, Belgrade (Yugoslavia)

    2000-06-01

    The paper presents an efficient methodology for the analysis of primary frequency control of electric power systems. This methodology continuously monitors the electromechanical transient processes with durations that last up to 30 s, occurring after the characteristic disturbances. It covers the period of short-term dynamic processes, appearing immediately after the disturbance, in which the dynamics of the individual synchronous machines is dominant, as well as the period with the uniform movement of all generators and restoration of their voltages. The characteristics of the developed methodology were determined based on the example of real electric power interconnection formed by the electric power systems of Yugoslavia, a part of Republic of Srpska, Romania, Bulgaria, former Yugoslav Republic of Macedonia, Greece and Albania (the second UCPTE synchronous zone). (author)

  17. Combining microbial cultures for efficient production of electricity from butyrate in a microbial electrochemical cell

    Science.gov (United States)

    Miceli, Joseph F.; Garcia-Peña, Ines; Parameswaran, Prathap; Torres, César I.; Krajmalnik-Brown, Rosa

    2014-01-01

    Butyrate is an important product of anaerobic fermentation; however, it is not directly used by characterized strains of the highly efficient anode respiring bacteria (ARB) Geobacter sulfurreducens in microbial electrochemical cells. By combining a butyrate-oxidizing community with a Geobacter rich culture, we generated a microbial community which outperformed many naturally derived communities found in the literature for current production from butyrate and rivaled the highest performing natural cultures in terms of current density (~11 A/m2) and Coulombic efficiency (~70%). Microbial community analyses support the shift in the microbial community from one lacking efficient ARB in the marine hydrothermal vent community to a community consisting of ~80% Geobacter in the anode biofilm. This demonstrates the successful production and adaptation of a novel microbial culture for generating electrical current from butyrate with high current density and high Coulombic efficiency, by combining two mixed micro bial cultures containing complementing biochemical pathways. PMID:25048958

  18. Radio-frequency current drive efficiency in the presence of ITBs and a dc electric field

    Science.gov (United States)

    Rosa, P. R. da S.; Mourão, R.; Ziebell, L. F.

    2009-05-01

    This paper discusses the current drive efficiency by the combined action of EC and LH waves in the presence of a dc electric field and transport, with an internal transport barrier. The transport is assumed to be produced by magnetic fluctuations. The study explores the different barrier parameters and their influence on the current drive efficiency. We study the subject by numerically solving the Fokker-Planck equation. Our main result is that the barrier depth and barrier width are important to determine the correct shape of the current density profile but not to determine the current drive efficiency, which is very little influenced by these parameters. We also found similar results for the influence of the level of magnetic fluctuations on the current density profile and on the current drive efficiency.

  19. Radio-frequency current drive efficiency in the presence of ITBs and a dc electric field

    International Nuclear Information System (INIS)

    Rosa, P.R. da S; Mourao, R.; Ziebell, L.F.

    2009-01-01

    This paper discusses the current drive efficiency by the combined action of EC and LH waves in the presence of a dc electric field and transport, with an internal transport barrier. The transport is assumed to be produced by magnetic fluctuations. The study explores the different barrier parameters and their influence on the current drive efficiency. We study the subject by numerically solving the Fokker-Planck equation. Our main result is that the barrier depth and barrier width are important to determine the correct shape of the current density profile but not to determine the current drive efficiency, which is very little influenced by these parameters. We also found similar results for the influence of the level of magnetic fluctuations on the current density profile and on the current drive efficiency.

  20. Distributional impacts of state-level energy efficiency policies in regional electricity markets

    International Nuclear Information System (INIS)

    Sahraei-Ardakani, Mostafa; Blumsack, Seth; Kleit, Andrew

    2012-01-01

    A number of U.S. states have passed legislation targeting energy efficiency and peak demand reduction. We study one such state, Pennsylvania, within the context of PJM, a regional electricity market covering numerous different states. Our focus is on the distributive impacts of this policy—specifically how the policy is likely to impact electricity prices in different areas of Pennsylvania and in the PJM market more generally. Such spatial differences in policy impacts are difficult to model and the transmission system is often ignored in policy studies. Our model estimates supply curves on a “zonal” basis within regional electricity markets and yields information on price and fuel utilization within each zone. We use the zonal supply curves estimated by our model to study regional impacts of energy-efficiency legislation on utilities both inside and outside of Pennsylvania. For most utilities in Pennsylvania, it would reduce the influence of natural gas on electricity price formation and increase the influence of coal. It would also save 2.1 to 2.8 percent of total energy cost in Pennsylvania in a year similar to 2009. The savings are lower than 0.5 percent in other PJM states and the prices may slightly increase in Washington, DC area. - Highlights: ► We model distributional impacts of energy efficiency and conservation policies. ► We use our model to study the impacts of Pennsylvania act 129. ► We estimate $235 million in annual savings for PA and $275 million for PJM. ► The prices decrease in most of the zones but the impacts are not uniform. ► The influence of coal on electricity prices increases relative to natural gas.

  1. The importance of comprehensiveness in renewable electricity and energy-efficiency policy

    International Nuclear Information System (INIS)

    Sovacool, Benjamin K.

    2009-01-01

    Based on extensive research interviews and supplemented with a review of the academic literature, this article assesses the best way to promote renewable energy and energy efficiency. It begins by briefly laying out why government intervention is needed, and then details the four most favored policy mechanisms identified by participants: eliminating subsidies for conventional and mature electricity technologies, pricing electricity accurately, passing a national feed-in tariff, and implementing a nationwide systems benefit fund to raise public awareness, protect lower income households, and administer demand side management programs. Drawing mostly from case studies in the United States, the article also discusses why these policy mechanisms must be implemented comprehensively, not individually, if the barriers to renewables and energy efficiency are to be overcome. (author)

  2. The importance of comprehensiveness in renewable electricity and energy-efficiency policy

    Energy Technology Data Exchange (ETDEWEB)

    Sovacool, Benjamin K. [Energy Governance Program, Centre on Asia and Globalisation, Lee Kuan Yew School of Public Policy, National University of Singapore, Singapore 259772 (Singapore)

    2009-04-15

    Based on extensive research interviews and supplemented with a review of the academic literature, this article assesses the best way to promote renewable energy and energy efficiency. It begins by briefly laying out why government intervention is needed, and then details the four most favored policy mechanisms identified by participants: eliminating subsidies for conventional and mature electricity technologies, pricing electricity accurately, passing a national feed-in tariff, and implementing a nationwide systems benefit fund to raise public awareness, protect lower income households, and administer demand side management programs. Drawing mostly from case studies in the United States, the article also discusses why these policy mechanisms must be implemented comprehensively, not individually, if the barriers to renewables and energy efficiency are to be overcome. (author)

  3. A highly efficient electric additive for enhancing photovoltaic performance of dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    N-cetylpyridinium iodide (N-CPI) as a new electric additive for enhancing photovoltaic performance of the dye-sensitized solar cell (DSSC) was studied.It showed high efficiency for enhancing both the open-circuit voltage and the short-circuit current density of DSSC when the suitable amount of N-CPI as 0.02 M was added in liquid electrolyte.The energy conversion effi- ciency of DSSC increased from 4.429% to 6.535%,with 47.55% enhancement.Therefore,it is a highly efficient electric addi- tive for DSSC.The intrinsic reason is owing to the special molecular structure of N-CPI,which contains two different polarity groups.As a surfactant,N-CPI could form ordered arrangement in liquid electrolyte,which affects the diffusing ability and the redox reaction of I-/I3-,and further affects the photovoltaic performance of DSSC.

  4. Efficient solution of ordinary differential equations modeling electrical activity in cardiac cells.

    Science.gov (United States)

    Sundnes, J; Lines, G T; Tveito, A

    2001-08-01

    The contraction of the heart is preceded and caused by a cellular electro-chemical reaction, causing an electrical field to be generated. Performing realistic computer simulations of this process involves solving a set of partial differential equations, as well as a large number of ordinary differential equations (ODEs) characterizing the reactive behavior of the cardiac tissue. Experiments have shown that the solution of the ODEs contribute significantly to the total work of a simulation, and there is thus a strong need to utilize efficient solution methods for this part of the problem. This paper presents how an efficient implicit Runge-Kutta method may be adapted to solve a complicated cardiac cell model consisting of 31 ODEs, and how this solver may be coupled to a set of PDE solvers to provide complete simulations of the electrical activity.

  5. Dealing with the paradox of energy efficiency promotion by electric utilities

    International Nuclear Information System (INIS)

    Sousa, José Luís; Martins, António Gomes; Jorge, Humberto

    2013-01-01

    Utility-based Demand-Side Management (DSM) programmes started after the oil crises of the 70's and were adopted by utilities as a standard practice. However, deregulation of the electricity industry threatened DSM. More recent concerns regarding energy dependence and environmental impact of energy use caused renewed attention on the utilities role in energy efficiency fostering. EE is presently a cross-cutting issue, influencing energy policy definition and regulatory activity worldwide. Some instruments for influencing the behaviour of electric utilities in the market are used by regulators, corresponding to both impositions and stimuli, such as defining savings targets or decoupling profits from energy sales. The paper addresses categories of regulatory instruments and refers to examples of countries and regions using these identified categories of instruments. Although some cases show voluntary involvement of utilities in EE promotion on the grounds of customer retention strategies, there is a clear prevalence of regulatory constrained markets where utilities rationally engage in energy efficiency promotion

  6. Energy Efficiency of Electrical Appliances - Effects of Instruments and Measures; Energieeffizienz bei Elektrogeraeten

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, C.U.; Bush, E.; Gasser, S.; Lingenhel, S.; Nipkow, J.

    2001-07-01

    This comprehensive report for the Swiss Federal Office of Energy presents the results of an analysis made of the market for electrical appliances in Switzerland with the aim of understanding the instruments and measures needed to improve energy efficiency better. The paper reports on reviews made of previous studies that were made in Switzerland and Germany and on interviews made with important persons and institutions in this field. Eight basic findings are listed concerning market expansion, technical progress, user behaviour, efficiency, possibilities for intervention, market forces, efficient appliances as a niche market and the competence lacking in the energy-efficiency area. Twelve basic points to be considered in the implementation of an energy-efficiency strategy are discussed and a list of requirements to be fulfilled by politics is presented. The results of the analysis for various sectors and the recommendations made for an implementation organisation are presented in detail. The report is concluded with a extract from the data base on the energy consumption of electrical appliances.

  7. Risk management and market efficiency on the Midwest Independent System Operator electricity exchange

    Science.gov (United States)

    Jones, Kevin

    Midwest Independent Transmission System Operator, Inc. (MISO) is a non-profit regional transmission organization (RTO) that oversees electricity production and transmission across thirteen states and one Canadian province. MISO also operates an electronic exchange for buying and selling electricity for each of its five regional hubs. MISO oversees two types of markets. The forward market, which is referred to as the day-ahead (DA) market, allows market participants to place demand bids and supply offers on electricity to be delivered at a specified hour the following day. The equilibrium price, known as the locational marginal price (LMP), is determined by MISO after receiving sale offers and purchase bids from market participants. MISO also coordinates a spot market, which is known as the real-time (RT) market. Traders in the real-time market must submit bids and offers by thirty minutes prior to the hour for which the trade will be executed. After receiving purchase and sale offers for a given hour in the real time market, MISO then determines the LMP for that particular hour. The existence of the DA and RT markets allows producers and retailers to hedge against the large fluctuations that are common in electricity prices. Hedge ratios on the MISO exchange are estimated using various techniques. No hedge ratio technique examined consistently outperforms the unhedged portfolio in terms of variance reduction. Consequently, none of the hedge ratio methods in this study meet the general interpretation of FASB guidelines for a highly effective hedge. One of the major goals of deregulation is to bring about competition and increased efficiency in electricity markets. Previous research suggests that electricity exchanges may not be weak-form market efficient. A simple moving average trading rule is found to produce statistically and economically significant profits on the MISO exchange. This could call the long-term survivability of the MISO exchange into question.

  8. Worm gear efficiency model considering misalignment in electric power steering systems

    Directory of Open Access Journals (Sweden)

    S. H. Kim

    2018-05-01

    Full Text Available This study proposes a worm gear efficiency model considering misalignment in electric power steering systems. A worm gear is used in Column type Electric Power Steering (C-EPS systems and an Anti-Rattle Spring (ARS is employed in C-EPS systems in order to prevent rattling when the vehicle goes on a bumpy road. This ARS plays a role of preventing rattling by applying preload to one end of the worm shaft but it also generates undesirable friction by causing misalignment of the worm shaft. In order to propose the worm gear efficiency model considering misalignment, geometrical and tribological analyses were performed in this study. For geometrical analysis, normal load on gear teeth was calculated using output torque, pitch diameter of worm wheel, lead angle and normal pressure angle and this normal load was converted to normal pressure at the contact point. Contact points between the tooth flanks of the worm and worm wheel were obtained by mathematically analyzing the geometry, and Hertz's theory was employed in order to calculate contact area at the contact point. Finally, misalignment by an ARS was also considered into the geometry. Friction coefficients between the tooth flanks were also researched in this study. A pin-on-disk type tribometer was set up to measure friction coefficients and friction coefficients at all conditions were measured by the tribometer. In order to validate the worm gear efficiency model, a worm gear was prepared and the efficiency of the worm gear was predicted by the model. As the final procedure of the study, a worm gear efficiency measurement system was set and the efficiency of the worm gear was measured and the results were compared with the predicted results. The efficiency considering misalignment gives more accurate results than the efficiency without misalignment.

  9. Enhanced Efficiency of Thermoelectric Generator by Optimizing Mechanical and Electrical Structures

    Directory of Open Access Journals (Sweden)

    Jinlong Chen

    2017-09-01

    Full Text Available Much attention has been paid to the application of low temperature thermal resources, especially for power generation in recent years. Most of the current commercialized thermal (including geothermal power-generation technologies convert thermal energy to electric energy indirectly, that is, making mechanical work before producing electricity. Technology using a thermoelectric generator (TEG, however, can directly transform thermal energy into electricity through the Seebeck effect. TEG technology has many advantages such as compactness, quietness, and reliability because there are no moving parts. One of the biggest disadvantages of TEGs is the low efficiency from thermal to electric energy. For this reason, we redesigned and modified our previous 1 KW (at a temperature difference of around 120 °C TEG system. The output power of the system was improved significantly, about 34.6% greater; the instantaneous efficiency of the TEG system could reach about 6.5%. Laboratory experiments have been conducted to measure the output power at different conditions: different connection modes between TEG modules, different mechanical structures, and different temperature differences between hot and cold sides. The TEG apparatus has been tested and the data have been presented. This kind of TEG power system can be applied in many thermal and geothermal sites with low temperature resources, including oil fields where fossil and geothermal energies are coproduced.

  10. Enhanced thermoelectric efficiency via orthogonal electrical and thermal conductances in phosphorene.

    Science.gov (United States)

    Fei, Ruixiang; Faghaninia, Alireza; Soklaski, Ryan; Yan, Jia-An; Lo, Cynthia; Yang, Li

    2014-11-12

    Thermoelectric devices that utilize the Seebeck effect convert heat flow into electrical energy and are highly desirable for the development of portable, solid state, passively powered electronic systems. The conversion efficiencies of such devices are quantified by the dimensionless thermoelectric figure of merit (ZT), which is proportional to the ratio of a device's electrical conductance to its thermal conductance. In this paper, a recently fabricated two-dimensional (2D) semiconductor called phosphorene (monolayer black phosphorus) is assessed for its thermoelectric capabilities. First-principles and model calculations reveal not only that phosphorene possesses a spatially anisotropic electrical conductance, but that its lattice thermal conductance exhibits a pronounced spatial-anisotropy as well. The prominent electrical and thermal conducting directions are orthogonal to one another, enhancing the ratio of these conductances. As a result, ZT may reach the criterion for commercial deployment along the armchair direction of phosphorene at T = 500 K and is close to 1 even at room temperature given moderate doping (∼2 × 10(16) m(-2) or 2 × 10(12) cm(-2)). Ultimately, phosphorene hopefully stands out as an environmentally sound thermoelectric material with unprecedented qualities. Intrinsically, it is a mechanically flexible material that converts heat energy with high efficiency at low temperatures (∼300 K), one whose performance does not require any sophisticated engineering techniques.

  11. What drives the efficiency of hard coal fuelled electricity generation? : an empirical assessment

    OpenAIRE

    Hoffmann, Tim; Voigt, Sebastian

    2009-01-01

    The efficiency of electricity generation in hard coal fired power plants varies considerably from country to country and over time. These differences occur both between developing and developed countries and between industrialised nations. The econometric analysis presented in this paper tests for the reasons of these discrepancies. In this examination abundance of hard coal and the price of hard coal are the two variables of our major interest. We assume that countries with an abundance of h...

  12. Technical efficiency of Spanish electrical sector: analysis of 1998-2001 period

    International Nuclear Information System (INIS)

    Gutierrez Moya, E.; Arevalo Quijada, M. T.

    2007-01-01

    The aim of this article is to analyse the technical efficiency of the energy Spanish sector in the course of the stage of liberalization (1998-2001). The study uses the non parametric approach of DEA (Data Envelopment Analysis) to derive Malaquist productivity indexes. In the study there is revealed the improvement of productivity of the mentioned companies, as well as the major differentiation between electrical considered companies. (Author) 23 refs

  13. EFFICIENT USE OF ENERGY IN A ELECTRIC ARC FURNANCE BY HEAT INTEGRATION APPROACH

    OpenAIRE

    Umesh Kumar, Dr. A K Prasad, Sourabh Kumar Soni

    2016-01-01

    Based on the principles of heat integration, the present work investigates the design and operational modifications which can lead to efficient energy integration in an electric arc furnace being operated with direct reduction process. This process is one of the oldest and most widely applied processes amongst the commercially used process in India. For the purpose of energy integration stream data is extracted from the actual flow sheet of the plant, which consists of supply and target tempe...

  14. Competition, regulation, and energy efficiency options in the electricity sector: Opportunities and challenges in developing countries

    Science.gov (United States)

    Phadke, Amol Anant

    This dissertation explores issues related to competition in and regulation of electricity sectors in developing countries on the backdrop of fundamental reforms in their electricity sectors. In most cases, electricity sector reforms promoted privatization based on the rationale that it will lower prices and improve quality. In Chapter 2, I analyze this rationale by examining the stated capital cost of independent (private) power producer's (IPPs) power projects in eight developing countries and find that the stated capital cost of projects selected via competitive bidding is on an average about 40% to 60% lower than that of the projects selected via negotiations, which, I argue, represents the extent to which the costs of negotiated projects are overstated. My results indicate that the policy of promoting private sector without an adequate focus on improving competition or regulation has not worked in most cases in terms of getting competitively priced private sector projects. Given the importance of facilitating effective competition or regulation, In Chapter 3, I examine the challenges and opportunities of establishing a competitive wholesale electricity market in a developing country context. I model a potential wholesale electricity market in Maharashtra (MH) state, India and find that it would be robustly competitive even in a situation of up-to five percent of supply shortage, when opportunities for demand response are combined with policies such as divestiture and requiring long-term contracts. My results indicate that with appropriate policies, some developing countries could establish competitive wholesale electricity markets. In Chapter 4, I focus on the demand side and analyze the cost effectiveness of improving end-use efficiency in an electricity sector with subsidized tariffs and electricity shortages and show that they offer the least expensive way of reducing shortages in Maharashtra State, India. In Chapter 5, I examine the costs of reducing carbon

  15. Marginal abatement cost curve for nitrogen oxides incorporating controls, renewable electricity, energy efficiency, and fuel switching.

    Science.gov (United States)

    Loughlin, Daniel H; Macpherson, Alexander J; Kaufman, Katherine R; Keaveny, Brian N

    2017-10-01

    A marginal abatement cost curve (MACC) traces out the relationship between the quantity of pollution abated and the marginal cost of abating each additional unit. In the context of air quality management, MACCs are typically developed by sorting control technologies by their relative cost-effectiveness. Other potentially important abatement measures such as renewable electricity, energy efficiency, and fuel switching (RE/EE/FS) are often not incorporated into MACCs, as it is difficult to quantify their costs and abatement potential. In this paper, a U.S. energy system model is used to develop a MACC for nitrogen oxides (NO x ) that incorporates both traditional controls and these additional measures. The MACC is decomposed by sector, and the relative cost-effectiveness of RE/EE/FS and traditional controls are compared. RE/EE/FS are shown to have the potential to increase emission reductions beyond what is possible when applying traditional controls alone. Furthermore, a portion of RE/EE/FS appear to be cost-competitive with traditional controls. Renewable electricity, energy efficiency, and fuel switching can be cost-competitive with traditional air pollutant controls for abating air pollutant emissions. The application of renewable electricity, energy efficiency, and fuel switching is also shown to have the potential to increase emission reductions beyond what is possible when applying traditional controls alone.

  16. Adoption of energy-efficient televisions for expanded off-grid electricity service

    Directory of Open Access Journals (Sweden)

    Won Young Park

    Full Text Available Even though they dominate the global television (TV market, light-emitting diode backlit liquid crystal display (LED-LCD TVs have received little attention for use with off-grid household-scale renewable energy systems, primarily because of high up-front costs. However, technological advances and price declines mean that these TVs can now provide the same level of electricity service as standard LED-LCD TVs offer but at lower total energy cost. Moreover, LED-LCD TVs are inherently direct-current (DC-powered devices and therefore well suited for use with off-grid solar home systems. We estimate that DC-powered energy-efficient LED-LCD TVs can decrease the retail purchase price of solar home systems by about 25% by allowing use of 50% smaller photovoltaics and battery capacities than would be needed for the same energy system to power a standard LED-LCD TV. We recommend that policies such as awards, bulk procurement, incentives, and energy labels be considered to facilitate the adoption of these energy-efficient TVs in off-grid settings. Keywords: DC television, TV energy efficiency, Electricity access, Off-grid electricity service, Cost-benefit analysis

  17. The influence of the trawl mouth opening size and net colour on catch efficiency during sampling of early fish stages

    Czech Academy of Sciences Publication Activity Database

    Jůza, T.; Čech, Martin; Kubečka, Jan; Vašek, Mojmír; Peterka, Jiří; Matěna, Josef

    2010-01-01

    Roč. 105, č. 3 (2010), s. 125-133 ISSN 0165-7836 R&D Projects: GA ČR(CZ) GP206/09/P266; GA AV ČR(CZ) 1QS600170504 Institutional research plan: CEZ:AV0Z60170517 Keywords : trawl efficiency * fry density * perch Subject RIV: EH - Ecology, Behaviour Impact factor: 1.656, year: 2010

  18. Distributed Processing System for Restoration of Electric Power Distribution Network Using Two-Layered Contract Net Protocol

    Science.gov (United States)

    Kodama, Yu; Hamagami, Tomoki

    Distributed processing system for restoration of electric power distribution network using two-layered CNP is proposed. The goal of this study is to develop the restoration system which adjusts to the future power network with distributed generators. The state of the art of this study is that the two-layered CNP is applied for the distributed computing environment in practical use. The two-layered CNP has two classes of agents, named field agent and operating agent in the network. In order to avoid conflicts of tasks, operating agent controls privilege for managers to send the task announcement messages in CNP. This technique realizes the coordination between agents which work asynchronously in parallel with others. Moreover, this study implements the distributed processing system using a de-fact standard multi-agent framework, JADE(Java Agent DEvelopment framework). This study conducts the simulation experiments of power distribution network restoration and compares the proposed system with the previous system. We confirmed the results show effectiveness of the proposed system.

  19. Implementing batteries in electrical grids. Possible operating modes for efficient business cases

    Energy Technology Data Exchange (ETDEWEB)

    Kittlaus, Barnabas; Schreider, Achim; Pour, Adel Hassan [Lahmeyer International GmbH, Bad Vilbel (Germany)

    2010-07-01

    For almost two decades, there has been a global trend towards the deregulation and the liberalisation of electricity markets. Previously, national or regional monopolistic utility companies provided services along the entire supply chain of electricity supply: Beginning with the operation of power plants and thus the generation of electricity, continuing through the development and the operation of transmission and local distribution grids, to the connection points. Since all assets belonged to the utility company, they could easily access generation units in order to provide balancing power for the safe and reliable operation of the electricity networks. With the objective of a more efficient and cheaper electricity supply by enabling competition, European Directive 96/92/EC (repealed by 2003/53/EC) enacted so-called ''unbundling'' which meant the break-up of utility companies as full service suppliers into the three service oriented entities; for electricity generation, transmission and supply. Whereas previously a single utility company provided the balancing of the electricity grid with its own assets, as a consequence of the directive, markets developed for the provision of diverse technical services. As long as the utility companies provided these services on their own, technical rather than economic aspects prevailed in their investment decisions. With the establishment of open markets for primary, secondary and tertiary reserve power, commercial interfaces had been established which force the respective specialised market actor to investment decisions driven primarily by economic aspects. At nearly the same time - around two decades ago, the first renewable energy systems (RES) provided electricity to public grids. In the 1990's their share of the overall electricity mix was negligible, but since the beginning of the new millennium more and more countries recognised the ecological and economic advantages of RES and established incentive systems for their

  20. Dependence of wheat and rice respiration on tissue nitrogen and the corresponding net carbon fixation efficiency under different rates of nitrogen application

    Science.gov (United States)

    Sun, Wenjuan; Huang, Yao; Chen, Shutao; Zou, Jianwen; Zheng, Xunhua

    2007-02-01

    To quantitatively address the role of tissue N in crop respiration under various agricultural practices, and to consequently evaluate the impact of synthetic fertilizer N application on biomass production and respiration, and hence net carbon fixation efficiency ( E ncf), pot and field experiments were carried out for an annual rotation of a rice-wheat cropping system from 2001 to 2003. The treatments of the pot experiments included fertilizer N application, sowing date and planting density. Different rates of N application were tested in the field experiments. Static opaque chambers were used for sampling the gas. The respiration as CO2 emission was detected by a gas chromatograph. A successive biomass clipping method was employed to determine the crop autotrophic respiration coefficient ( R a). Results from the pot experiments revealed a linear relationship between R a and tissue N content as R a = 4.74N-1.45 ( R 2 = 0.85, P < 0.001). Measurements and calculations from the field experiments indicated that fertilizer N application promoted not only biomass production but also increased the respiration of crops. A further investigation showed that the increase of carbon loss in terms of respiration owing to fertilizer N application exceeded that of net carbon gain in terms of aboveground biomass when fertilizer N was applied over a certain rate. Consequently, the E ncf declined as the N application rate increased.

  1. Investigation of Electrical Energy Efficiency Use in an Automobile Assembly Industry

    Directory of Open Access Journals (Sweden)

    Jacob TSADO

    2016-12-01

    Full Text Available This research work investigated the electrical energy efficiency improvement and cost saving potentials for automobile assembly plant; a case of Peugeot Automobile Nigeria Limited. The study identified lighting system as a major source through which energy is being wasted, hence efficient energy saving lighting systems are being proffered; also saving accrued were determined to justify their deployment. In the course of this work, an energy saving calculating tool was developed to calculate energy saving capabilities using energy efficient lamps. With ample devotion to the implementation of the recommendations made, the cost of energy per car will be drastically reduced while profits are also made simultaneously. In all, more cars will be produced thus translating to more employment opportunities in the industry.

  2. Transmission cost allocation for an efficient tariff action of electricity in a liberalised market

    International Nuclear Information System (INIS)

    Bassi, C.; Caldon, R.; Lorenzoni, A.

    1999-01-01

    The work is focused on the evaluation of the costs of an electricity transmission system operator and on their allocation among the users of the grid in liberalized market. After a recall of the goals of an efficient tariff for transmission, an original method for the cost allocation is proposed called ZI. Based on the marginal cost approach, this method could be the base for setting an efficient transmission tariff that at the same time covers costs and stimulates efficient behaviours. The performances of such an approach have been tested on a real 47 bus grid and ZI tariffs have been compared to the traditional postage stamp ones, highlighting the strong differences between them [it

  3. A traction control strategy with an efficiency model in a distributed driving electric vehicle.

    Science.gov (United States)

    Lin, Cheng; Cheng, Xingqun

    2014-01-01

    Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention.

  4. A Traction Control Strategy with an Efficiency Model in a Distributed Driving Electric Vehicle

    Science.gov (United States)

    Lin, Cheng

    2014-01-01

    Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention. PMID:25197697

  5. On the impact of D2D traffic offloading on energy efficiency in green LTE-A HetNets

    KAUST Repository

    Yaacoub, Elias E.

    2014-08-11

    In this paper, the interplay between cooperative device-to-device (D2D) communications and green cellular communications in the long term evolution (LTE) and LTE-advanced (LTE-A) cellular systems is investigated. An efficient approach for grouping mobile terminals (MTs) into cooperative clusters is described. In each cluster, MTs cooperate via D2D communications to share content of common interest. In addition, an energy-efficient approach for putting base stations in sleep mode in an LTE-A heterogeneous network is presented. Finally, both methods are combined in order to ensure green communications for both the users\\' MTs and the operator\\'s base stations. The presented techniques are investigated in the framework of orthogonal frequency division multiple access-based state-of-the-art LTE cellular networks, while taking resource allocation and intercell interference into account. Results show that the proposed approach leads to energy savings for both the operator and the MTs, while leading to enhanced quality of service for mobile users. Copyright © 2014 John Wiley & Sons, Ltd.

  6. Field Measurements of Heating Efficiency of Electric Forced-Air Furnaces in Six Manufactured Homes.

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Bob; Palmiter, Larry S.; Siegel, Jeff

    1994-07-26

    This report presents the results of field measurements of heating efficiency for six manufactured homes in the Pacific Northwest heated with electric forced-air systems. This is the first in a series of regional and national efforts to measure in detail the heating efficiency of manufactured homes. Only six homes were included in this study because of budgetary constraints; therefore this is not a representative sample. These investigations do provide some useful information on the heating efficiency of these homes. Useful comparisons can be drawn between these study homes and site-built heating efficiencies measured with a similar protocol. The protocol used to test these homes is very similar to another Ecotope protocol used in the study conducted in 1992 and 1993 for the Bonneville Power Administration to test the heating efficiency of 24 homes. This protocol combined real-time power measurements of furnace energy usage with energy usage during co-heat periods. Accessory data such as house and duct tightness measurements and tracer gas measurements were used to describe these homes and their heating system efficiency. Ensuring that manufactured housing is constructed in an energy and resource efficient manner is of increasing concern to manufactured home builders and consumers. No comparable work has been done to measure the heating system efficiency of MCS manufactured homes, although some co-heat tests have been performed on manufactured homes heated with natural gas to validate HUD thermal standards. It is expected that later in 1994 more research of this kind will be conducted, and perhaps a less costly and less time-consuming method for testing efficiencies will be develops.

  7. Efficiency effects of observed and unobserved heterogeneity: Evidence from Norwegian electricity distribution networks

    International Nuclear Information System (INIS)

    Growitsch, Christian; Jamasb, Tooraj; Wetzel, Heike

    2012-01-01

    Since the 1990s, efficiency and benchmarking analysis has increasingly been used in network utilities research and regulation. A recurrent concern is the effect of observable environmental factors that are beyond the influence of firms and unobserved factors that are not identifiable on measured cost and quality performance of firms. This paper analyses the effect of observed geographic and weather factors and unobserved heterogeneity on a set of 128 Norwegian electricity distribution utilities for the 2001–2004 period. We utilise data on 78 geographic and weather variables to identify real economic inefficiency while controlling for observed and unobserved heterogeneity. We use the Factor Analysis technique to reduce the number of environmental factors into few composite variables and to avoid the problem of multicollinearity. In order to identify firm-specific inefficiency, we then estimate a pooled version of the established stochastic frontier model of Aigner et al. (1977) and the recent true random effects model of Greene (2004; 2005a,b) without and with environmental variables. The results indicate that the observed environmental factors have a rather limited influence on the utilities' average efficiency and the efficiency rankings. Moreover, the difference between the average efficiency scores and the efficiency rankings among the pooled and the true random effects models imply that the type of SFA model used is highly influencing the efficiency estimates.

  8. Efficient thermo-mechanical generation of electricity from the heat of radioisotopes

    International Nuclear Information System (INIS)

    Cooke-Yarborough, E.H.; Yeats, F.W.

    1975-01-01

    The thermomechanical generator uses a thermomechanical oscillator to convert heat efficiently into a mechanical oscillation which in turn excites a suitable transducer to generate alternating electricity. The thermomechanical oscillator used is based on the Stirling cycle, but avoids the need for rotary motion and for sliding pistons by having a mechanically-resonant, spring-suspended displacer, and by using an oscillating metal diaphragm to provide the mechanical output. The diaphragm drives an alternator consisting of a spring-suspended permanent magnet oscillating between fixed pole pieces which carry the electrical power output windings. Because a thermomechanical generator is much more efficient than a thermo-electric generator at comparable temperatures, it is particularly suitable for use with a radioisotope heat source. The amounts of radioisotope and of shielding required are both greatly reduced. A machine heated by radioisotopes and delivering 10.7W ac at 80Hz began operating in October, 1974. Operating experience with this machine is reported, and these results, together with those obtained with higher-powered machines heated by other means, are used to calculate characteristics and performance of thermo-mechanical radioisotope generators capable of using heat sources such as the waste-management 90 Sr radioisotope sources becoming available from the US nuclear waste management programme. A design to use one of these heat sources in a 52-W underwater generator is described

  9. Net Neutrality

    DEFF Research Database (Denmark)

    Savin, Andrej

    2017-01-01

    Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else.......Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else....

  10. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 5: Combined gas-steam turbine cycles. [energy conversion efficiency in electric power plants

    Science.gov (United States)

    Amos, D. J.; Foster-Pegg, R. W.; Lee, R. M.

    1976-01-01

    The energy conversion efficiency of gas-steam turbine cycles was investigated for selected combined cycle power plants. Results indicate that it is possible for combined cycle gas-steam turbine power plants to have efficiencies several point higher than conventional steam plants. Induction of low pressure steam into the steam turbine is shown to improve the plant efficiency. Post firing of the boiler of a high temperature combined cycle plant is found to increase net power but to worsen efficiency. A gas turbine pressure ratio of 12 to 1 was found to be close to optimum at all gas turbine inlet temperatures that were studied. The coal using combined cycle plant with an integrated low-Btu gasifier was calculated to have a plant efficiency of 43.6%, a capitalization of $497/kW, and a cost of electricity of 6.75 mills/MJ (24.3 mills/kwh). This combined cycle plant should be considered for base load power generation.

  11. Getting to Net Zero

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-01

    The technology necessary to build net zero energy buildings (NZEBs) is ready and available today, however, building to net zero energy performance levels can be challenging. Energy efficiency measures, onsite energy generation resources, load matching and grid interaction, climatic factors, and local policies vary from location to location and require unique methods of constructing NZEBs. It is recommended that Components start looking into how to construct and operate NZEBs now as there is a learning curve to net zero construction and FY 2020 is just around the corner.

  12. A nonlinear efficient layerwise finite element model for smart piezolaminated composites under strong applied electric field

    International Nuclear Information System (INIS)

    Kapuria, S; Yaqoob Yasin, M

    2013-01-01

    In this work, we present an electromechanically coupled efficient layerwise finite element model for the static response of piezoelectric laminated composite and sandwich plates, considering the nonlinear behavior of piezoelectric materials under strong electric field. The nonlinear model is developed consistently using a variational principle, considering a rotationally invariant second order nonlinear constitutive relationship, and full electromechanical coupling. In the piezoelectric layer, the electric potential is approximated to have a quadratic variation across the thickness, as observed from exact three dimensional solutions, and the equipotential condition of electroded piezoelectric surfaces is modeled using the novel concept of an electric node. The results predicted by the nonlinear model compare very well with the experimental data available in the literature. The effect of the piezoelectric nonlinearity on the static response and deflection/stress control is studied for piezoelectric bimorph as well as hybrid laminated plates with isotropic, angle-ply composite and sandwich substrates. For high electric fields, the difference between the nonlinear and linear predictions is large, and cannot be neglected. The error in the prediction of the smeared counterpart of the present theory with the same number of primary displacement unknowns is also examined. (paper)

  13. The Fuzzy Logic Method to Efficiently Optimize Electricity Consumption in Individual Housing

    Directory of Open Access Journals (Sweden)

    Sébastien Bissey

    2017-10-01

    Full Text Available Electricity demand shifting and reduction still raise a huge interest for end-users at the household level, especially because of the ongoing design of a dynamic pricing approach. In particular, end-users must act as the starting point for decreasing their consumption during peak hours to prevent the need to extend the grid and thus save considerable costs. This article points out the relevance of a fuzzy logic algorithm to efficiently predict short term load consumption (STLC. This approach is the cornerstone of a new home energy management (HEM algorithm which is able to optimize the cost of electricity consumption, while smoothing the peak demand. The fuzzy logic modeling involves a strong reliance on a complete database of real consumption data from many instrumented show houses. The proposed HEM algorithm enables any end-user to manage his electricity consumption with a high degree of flexibility and transparency, and “reshape” the load profile. For example, this can be mainly achieved using smart control of a storage system coupled with remote management of the electric appliances. The simulation results demonstrate that an accurate prediction of STLC gives the possibility of achieving optimal planning and operation of the HEM system.

  14. Pollution from the electric power sector in Japan and efficient pollution reduction

    International Nuclear Information System (INIS)

    Matsushita, Kyohei; Yamane, Fumihiro

    2012-01-01

    Under the scheme of the Kyoto Protocol, there are plans for the efficient reduction of carbon dioxide emissions. In the electric power sector, nuclear power generation, which emits no carbon dioxide in the process of generating electricity, has come under scrutiny. However, this energy produces a new environmental issue: the disposal of radioactive waste. First, we derive shadow prices of carbon dioxide and low-level waste as marginal abatement costs in the case of the electric power sector in Japan, employing a directional output distance function. It is found that the shadow prices are US$39 per tonne for carbon dioxide and US$1531 per liter for low-level waste. Secondly, we calculate the indirect Morishima elasticity between carbon dioxide and low-level waste in order to identify their substitutability, and it is found that the substitution of low-level waste for carbon dioxide is easier than the reverse. This result suggests that, with the amount of generated electricity fixed, carbon dioxide can be substituted more easily by low-level waste when the relative price of carbon dioxide increases, for example, as a result of implementation of a carbon dioxide tax or an emissions trading system.

  15. Coal-Powered Electric Generating Unit Efficiency and Reliability Dialogue: Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Emmanuel [Energetics, Inc., Columbia, MD (United States)

    2018-02-01

    Coal continues to play a critical role in powering the Nation’s electricity generation, especially for baseload power plants. With aging coal generation assets facing decreased performance due to the state of the equipment, and with challenges exacerbated by the current market pressures on the coal sector, there are opportunities to advance early-stage technologies that can retrofit or replace equipment components. These changes will eventually result in significant improvements in plant performance once further developed and deployed by industry. Research and development in areas such as materials, fluid dynamics, fuel properties and preparation characteristics, and a new generation of plant controls can lead to new components and systems that can help improve the efficiency and reliability of coal-fired power plants significantly, allowing these assets to continue to provide baseload power. Coal stockpiles at electricity generation plants are typically large enough to provide 30 to 60 days of power prior to resupply—significantly enhancing the stability and reliability of the U.S. electricity sector. Falling prices for non-dispatchable renewable energy and mounting environmental regulations, among other factors, have stimulated efforts to improve the efficiency of these coal-fired electric generating units (EGUs). In addition, increased reliance on natural gas and non-dispatchable energy sources has spurred efforts to further increase the reliability of coal EGUs. The Coal Powered EGU Efficiency and Reliability Dialogue brought together stakeholders from across the coal EGU industry to discuss methods for improvement. Participants at the event reviewed performance-enhancing innovations in coal EGUs, discussed the potential for data-driven management practices to increase efficiency and reliability, investigated the impacts of regulatory compliance on coal EGU performance, and discussed upcoming challenges for the coal industry. This report documents the key

  16. High-Efficiency, Multijunction Solar Cells for Large-Scale Solar Electricity Generation

    Science.gov (United States)

    Kurtz, Sarah

    2006-03-01

    A solar cell with an infinite number of materials (matched to the solar spectrum) has a theoretical efficiency limit of 68%. If sunlight is concentrated, this limit increases to about 87%. These theoretical limits are calculated using basic physics and are independent of the details of the materials. In practice, the challenge of achieving high efficiency depends on identifying materials that can effectively use the solar spectrum. Impressive progress has been made with the current efficiency record being 39%. Today's solar market is also showing impressive progress, but is still hindered by high prices. One strategy for reducing cost is to use lenses or mirrors to focus the light on small solar cells. In this case, the system cost is dominated by the cost of the relatively inexpensive optics. The value of the optics increases with the efficiency of the solar cell. Thus, a concentrator system made with 35%- 40%-efficient solar cells is expected to deliver 50% more power at a similar cost when compare with a system using 25%-efficient cells. Today's markets are showing an opportunity for large concentrator systems that didn't exist 5-10 years ago. Efficiencies may soon pass 40% and ultimately may reach 50%, providing a pathway to improved performance and decreased cost. Many companies are currently investigating this technology for large-scale electricity generation. The presentation will cover the basic physics and more practical considerations to achieving high efficiency as well as describing the current status of the concentrator industry. This work has been authored by an employee of the Midwest Research Institute under Contract No. DE- AC36-99GO10337 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow

  17. High efficiency particulate air filter technology from 1980 to 1985 in the Central Electricity Generating Board

    International Nuclear Information System (INIS)

    Skledon, R.; Taylor, S.; Fern, C.; Stead, M.

    1986-01-01

    This paper examines at the Central Electricity Generating Board's methods of High Efficiency Particulate Air (1,700 m 3 /hr) filter testing from conception to the present day. The choice of the test and the early results are looked at followed by the development using new test equipment for checking ladderframe systems. The need for the drawing up of the Central Electricity Generating Board 743401 Standard for filter manufacture and its effect on full implementation is looked into. The advantages and disadvantages of our test procedures are reflected upon and the future developments in test methods and filters for use by the C.E.G.B. in their power stations are discussed. (author)

  18. Electrical Matching at Metal/Molecule Contacts for Efficient Heterogeneous Charge Transfer.

    Science.gov (United States)

    Sato, Shino; Iwase, Shigeru; Namba, Kotaro; Ono, Tomoya; Hara, Kenji; Fukuoka, Atsushi; Uosaki, Kohei; Ikeda, Katsuyoshi

    2018-02-27

    In a metal/molecule hybrid system, unavoidable electrical mismatch exists between metal continuum states and frontier molecular orbitals. This causes energy loss in the electron conduction across the metal/molecule interface. For efficient use of energy in a metal/molecule hybrid system, it is necessary to control interfacial electronic structures. Here we demonstrate that electrical matching between a gold substrate and π-conjugated molecular wires can be obtained by using monatomic foreign metal interlayers, which can change the degree of d-π* back-donation at metal/anchor contacts. This interfacial control leads to energy level alignment between the Fermi level of the metal electrode and conduction molecular orbitals, resulting in resonant electron conduction in the metal/molecule hybrid system. When this method is applied to molecule-modified electrocatalysts, the heterogeneous electrochemical reaction rate is considerably improved with significant suppression of energy loss at the internal electron conduction.

  19. New evaluation methodology of regenerative braking contribution to energy efficiency improvement of electric vehicles

    International Nuclear Information System (INIS)

    Qiu, Chengqun; Wang, Guolin

    2016-01-01

    Highlights: • Two different contribution ratio evaluation parameters according to the deceleration braking process are proposed. • Methodologies for calculating the contribution made by regenerative brake to improve vehicle energy efficiency are proposed. • Road test results imply that the proposed parameters are effective. - Abstract: Comprehensive research is conducted on the design and control of a regenerative braking system for electric vehicles. The mechanism and evaluation methods of contribution brought by regenerative braking to improve electric vehicle’s energy efficiency are discussed and analyzed by the energy flow. Methodologies for calculating the contribution made by regenerative brake are proposed. Additionally a new regenerative braking control strategy called “serial 2 control strategy” is introduced. Moreover, two control strategies called “parallel control strategy” and “serial 1 control strategy” are proposed as the comparative control strategy. Furthermore, two different contribution ratio evaluation parameters according to the deceleration braking process are proposed. Finally, road tests are carried out under China typical city regenerative driving cycle standard with three different control strategies. The serial 2 control strategy offers considerably higher regeneration efficiency than the parallel strategy and serial 1 strategy.

  20. What is the most energy efficient route for biogas utilization: Heat, electricity or transport?

    International Nuclear Information System (INIS)

    Hakawati, Rawan; Smyth, Beatrice M.; McCullough, Geoffrey; De Rosa, Fabio; Rooney, David

    2017-01-01

    Highlights: •The paper developed an assessment tool for analyzing biogas utilization routes. •The LCA methodology was used to allow a uniform assessment of the biogas system. •“% energy efficiency” was used as the functional unit for assessment. •49 biogas-to-energy routes were assessed based on their final useful energy form. •The framework aids policy makers in the decision process for biogas exploitation. -- Abstract: Biogas is a renewable energy source that can be used either directly or through various pathways (e.g. upgrading to bio-methane, use in a fuel cell or conversion to liquid fuels) for heat, electricity generation or mechanical energy for transport. However, although there are various options for biogas utilization, there is limited guidance in the literature on the selection of the optimum route, and comparison between studies is difficult due to the use of different analytical frameworks. The aim of this paper was to fill that knowledge gap and to develop a consistent framework for analysing biogas-to-energy exploitation routes. The paper evaluated 49 biogas-to-energy routes using a consistent life cycle analysis method focusing on energy efficiency as the chosen crtierion. Energy efficiencies varied between 8% and 54% for electricity generation; 16% and 83% for heat; 18% and 90% for electricity and heat; and 4% and 18% for transport. Direct use of biogas has the highest efficiencies, but the use of this fuel is typically limited to sites co-located with the anaerobic digestion facility, limiting available markets and applications. Liquid fuels have the advantage of versatility, but the results show consistently low efficiencies across all routes and applications. The energy efficiency of bio-methane routes competes well with biogas and comes with the advantage that it is more easily transported and used in a wide variety of applications. The results were also compared with fossil fuels and discussed in the context of national

  1. Establishing strategic energy assessment indicators for Zimbabwe: A key to improving electrical energy efficiency

    Science.gov (United States)

    Goto, Felix

    In Zimbabwe, there is still very little realization of the potential of demand side management (DSM) to increase industrial energy efficiency. Without clear guidelines that indicate the most economic energy efficiency strategies to implement, it is difficult for industry to easily evaluate the benefits of energy assessments. This research focused on establishing and evaluating indicators that guide correct implementation of energy assessments into Zimbabwean industry. This quantitative and qualitative study used a theoretic approach to develop indicators that identified industrial subsectors that should be targeted for DSM interventions. This may bring about reduction in energy demand in high power consuming Zimbabwean industrial companies, which were compared with energy utility performances of similar industrial companies in countries located in other parts of the world. This research used pattern-matching, categorical aggregation, and stochastic frontier regression analysis for data analysis. In maximizing electrical efficiency, the implications of this study may be used by individual companies in Zimbabwe to perform energy efficiency self-diagnoses, operational efficiency evaluations, and capital resource justifications. From a societal perspective, this study may benefit Zimbabwe because it provides opportunities for the alleviation of both shortages in power supply and the capital constraints of building new generating capacity. This study will also benefit ordinary Zimbabweans by lowering energy costs and providing reliable power. This promotes sustainable economic growth and lowers the need for foreign currency to import power.

  2. Unitary assessment of economical efficiency of the energy resources for electricity production in Romania

    International Nuclear Information System (INIS)

    Luca, Gheorghe

    2004-01-01

    In our country, within the studies, on which the development strategies of power output are based on, the assessment of the economical efficiency of the use of two main energetic resources, the fuel used in cogeneration thermal power plants and the water used in hydropower plants respectively, was made in compliance with non-unitary specific norms. In contradiction with the degree of utilization of hydroelectric resources, realized all over the world in the developed countries (80-90%) resulted that in our country, where the degree of utilization is only 40%, the use of hydroelectric potential is not yet justified from technical-economical point of view. This anomaly was determined by the cause of non-unitary assessment of the economic efficiency for the cogeneration thermo-power plants and hydropower plants. This paper presents comparatively the elements, which were to the basis of the assessment of the economic efficiency for two types of electrical power plants, and one presents a proposal in the aim to perform a unitary assessment of the economical efficiency by applying efficiently the laws in force. (author)

  3. Improving the efficiency of phytoremediation using electrically charged plant and chelating agents.

    Science.gov (United States)

    Tahmasbian, Iman; Safari Sinegani, Ali Akbar

    2016-02-01

    The low efficiency of phytoremediation is a considerable problem that limits the application of this environmentally friendly method on heavy metal-polluted soils. The combination of chelate-assisted phytoextraction and electrokinetic remediation could offer new opportunities to improve the effectiveness of phytoextraction. The current experiment aims to investigate the effects of electrical fields and chelating agents on phytoremediation efficiency. In a pot experiment using mine soil, poultry manure extract (PME), cow manure extract (CME), and ethylenediaminetetraacetic acid (EDTA) were applied to soil as chelating agents (2 g kg(-1)) at the beginning of the flowering stage. A week later, Helianthus annuus (sunflower) was negatively charged by inserting a stainless steel needle with 10 and 30 V DC electricity in the lowest part of the stems for 1 h each day for a 14-day period. At the end of the experiment, the shoot and root dry weight, lead (Pb) concentration in plant organs, translocation factor (TF), metal uptake index (UI), and soil available Pb (diethylene triamine pentaacetic acid (DTPA) extractable) were detected. Results indicated that the application of electrical fields had no significant impact on the shoot and root dry weights, while Pb concentration and UI increased in the 10-V EDTA treatment by 500 % compared to control. There was no significant difference between UI in 30- and 10-V EDTA treatments. Soil available Pb significantly increased in the 30-V treated soil. A positive correlation was observed between the available Pb in soil near the root and Pb concentration in shoot, its TF, and UI. In conclusion, a negatively charged plant along with the application of EDTA significantly increased the phytoremediation efficiency.

  4. Assessing the Energy Content of System Frequency and Electric Vehicle Charging Efficiency for Ancillary Service Provision

    DEFF Research Database (Denmark)

    Thingvad, Andreas; Ziras, Charalampos; Hu, Junjie

    2017-01-01

    The purpose of this paper is to quantify the effect of biased system frequency deviations and charger losses in order for an aggregation of electric vehicles (EVs) to provide reliable primary frequency control (PFC). A data set consisting of one year of frequency measurements of the Nordic....... Additionally, a method for calculating the expected energy loss caused by continuous charging and discharging is presented together with efficiency measurements of a commercial bidirectional EV charger. It is found that during a year, the energy balance of the service provider, relative to the grid, is within...

  5. The Efficiency of the Regulation for Horizontal Mergers Among Electricity Distribution Operators in Norway

    DEFF Research Database (Denmark)

    Agrell, Per J.; Bogetoft, Peter; Gammeltvedt, Thor Erik

    2015-01-01

    the attractiveness of mergers. Norway is one country having implemented an ex ante regulation for mergers among electricity distribution operators (DSOs). We investigate whether the actual mergers of Norwegian DSOs in the period 1995-2004 can be rationalized as cost saving exercises or whether they should...... to identify plausible pre-merger motivations. We also discuss the possibility to gain from strategic gaming in the regulation. We compare the regulated revenues and the regulated efficiency improvement requirements before and after the mergers. We find limited potential cost gains ex ante but some improvement...

  6. Towards the rationalization of catalytic activity values by means of local hyper-softness on the catalytic site: a criticism about the use of net electric charges.

    Science.gov (United States)

    Ignacio Martínez-Araya, Jorge; Grand, André; Glossman-Mitnik, Daniel

    2015-11-28

    By means of the Spin-Polarized Conceptual Density Functional Theory (SP-CDFT), three 2,6-bis(imino)pyridine catalysts based on iron(II), used for polymerization of ethylene, were studied. The catalysts differed by the substituent group, bearing either -H, -NO2 or -OCH3. To date, catalytic activity, a purely experimental parameter measuring the mass of polyethylene produced per millimole of iron per time and pressure unit at a fixed temperature, has not been explained in terms of local hyper-softness. The latter is a purely theoretical parameter designed for quantifying electronic effects; it is measured using the metal atom responsible for the coordination process with the monomer (ethylene). Because steric effects are not relevant in these kinds of catalysts and only electronic effects drive the catalytic process, an interesting link is found between catalytic activity and the local hyper-softness condensed on the iron atom by means of four functionals (B3LYP, BP86, B97D, and VSXC). This work demonstrates that the use of local hyper-softness, predicted by the SP-CDFT, is a suitable parameter for explaining order relationships among catalytic activity values, thus quantifying the electronic influence of the substituent group inducing this difference; the use of only net electric charges does not lead to clear conclusions. This finding can aid in estimating catalytic activities leading to a more rational design of new catalysts via computational chemistry.

  7. Very High Efficiency Reactor (VHER) Concepts for Electrical Power Generation and Hydrogen Production

    International Nuclear Information System (INIS)

    PARMA JR, EDWARD J.; PICKARD, PAUL S.; SUO-ANTTILA, AHTI JORMA

    2003-01-01

    The goal of the Very High Efficiency Reactor study was to develop and analyze concepts for the next generation of nuclear power reactors. The next generation power reactor should be cost effective compared to current power generation plant, passively safe, and proliferation-resistant. High-temperature reactor systems allow higher electrical generating efficiencies and high-temperature process heat applications, such as thermo-chemical hydrogen production. The study focused on three concepts; one using molten salt coolant with a prismatic fuel-element geometry, the other two using high-pressure helium coolant with a prismatic fuel-element geometry and a fuel-pebble element design. Peak operating temperatures, passive-safety, decay heat removal, criticality, burnup, reactivity coefficients, and material issues were analyzed to determine the technical feasibility of each concept

  8. Energy-efficient biomass processing with pulsed electric fields for bioeconomy and sustainable development.

    Science.gov (United States)

    Golberg, Alexander; Sack, Martin; Teissie, Justin; Pataro, Gianpiero; Pliquett, Uwe; Saulis, Gintautas; Stefan, Töpfl; Miklavcic, Damijan; Vorobiev, Eugene; Frey, Wolfgang

    2016-01-01

    Fossil resources-free sustainable development can be achieved through a transition to bioeconomy, an economy based on sustainable biomass-derived food, feed, chemicals, materials, and fuels. However, the transition to bioeconomy requires development of new energy-efficient technologies and processes to manipulate biomass feed stocks and their conversion into useful products, a collective term for which is biorefinery. One of the technological platforms that will enable various pathways of biomass conversion is based on pulsed electric fields applications (PEF). Energy efficiency of PEF treatment is achieved by specific increase of cell membrane permeability, a phenomenon known as membrane electroporation. Here, we review the opportunities that PEF and electroporation provide for the development of sustainable biorefineries. We describe the use of PEF treatment in biomass engineering, drying, deconstruction, extraction of phytochemicals, improvement of fermentations, and biogas production. These applications show the potential of PEF and consequent membrane electroporation to enable the bioeconomy and sustainable development.

  9. Aboveground net primary productivity and rainfall use efficiency of grassland on three soils after two years of exposure to a subambient to superambient CO2 gradient.

    Science.gov (United States)

    Fay, P. A.; Polley, H. W.; Jin, V. L.

    2008-12-01

    Atmospheric CO2 concentrations (CA) have increased by about 100 μL L-1 over the last 250 years to ~ 380 μL L-1, the highest values in the last half-million years, and CA is expected to continue to increase to greater than 500 μL L-1 by 2100. CO2 enrichment has been shown to affect many ecosystem processes, but experiments typically examine only two or a few levels of CA, and are typically constrained to one soil type. However, soil hydrologic properties differ across the landscape. Therefore, variation in the impacts of increasing CA on ecosystem function on different soil types must be understood to model and forecast ecosystem function under future CA and climate scenarios. Here we evaluate the aboveground net primary productivity (ANPP) of grassland plots receiving equal rainfall inputs (from irrigation) and exposed to a continuous gradient (250 to 500 μL L-1) of CA in the Lysimeter CO2 Gradient Experiment in central Texas, USA. Sixty intact soil monoliths (1 m2 x 1.5 m deep) taken from three soil types (Austin silty clay, Bastrop sandy loam, Houston clay) and planted to seven native tallgrass prairie grasses and forbs were exposed to the CA gradient beginning in 2006. Aboveground net primary productivity was assessed by end of season (November) harvest of each species in each monolith. Total ANPP of all species was 35 to 50% greater on Bastrop and Houston soils compared to Austin soils in both years (p Solidago canadensis strongly increased with increasing CA, with S. nutans responding more strongly on Bastrop and Houston soils (p = 0.053), indicating that increased greater rainfall use efficiency at high CA on these productive soils was associated with increased dominance by these species. In contrast, the grass Bouteloua curtipendula decreased in biomass with increasing CA, especially on Austin and Bastrop soils. The least productive species were the grass Tridens albescens, the legume Desmanthus illinoensis, and the forb Salvia azurea, and these showed

  10. Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy covariance, biometric and continuous soil chamber measurements

    Directory of Open Access Journals (Sweden)

    D. Zanotelli

    2013-05-01

    Full Text Available Carbon use efficiency (CUE, the ratio of net primary production (NPP over gross primary production (GPP, is a functional parameter that could possibly link the current increasingly accurate global GPP estimates with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, NPP and allocation patterns in different plant organs in an apple orchard during a complete year (2010. We applied a measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard, both net ecosystem production and gross primary production on a yearly basis, 380 ± 30 g C m−2 and 1263 ± 189 g C m−2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruit: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71

  11. Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy-covariance, biometric and continuous soil chamber measurements

    Science.gov (United States)

    Zanotelli, D.; Montagnani, L.; Manca, G.; Tagliavini, M.

    2012-10-01

    Carbon use efficiency (CUE) is a functional parameter that could possibly link the current increasingly accurate global estimates of gross primary production with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, net primary production (NPP) and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a~measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross-check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard both net ecosystem production and gross primary production on yearly basis, 380 ± 30 g C m-2 and 1263 ± 189 g C m-2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruits: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.09, was higher than the previously suggested

  12. Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy covariance, biometric and continuous soil chamber measurements

    Science.gov (United States)

    Zanotelli, D.; Montagnani, L.; Manca, G.; Tagliavini, M.

    2013-05-01

    Carbon use efficiency (CUE), the ratio of net primary production (NPP) over gross primary production (GPP), is a functional parameter that could possibly link the current increasingly accurate global GPP estimates with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, NPP and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard, both net ecosystem production and gross primary production on a yearly basis, 380 ± 30 g C m-2 and 1263 ± 189 g C m-2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruit: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.12, was higher

  13. Petri Nets

    Indian Academy of Sciences (India)

    GENERAL I ARTICLE ... In Part 1 of this two-part article, we have seen im- ..... mable logic controller and VLSI arrays, office automation systems, workflow management systems, ... complex discrete event and real-time systems; and Petri nets.

  14. Aeration to degas CO{sub 2}, increase pH, and increase iron oxidation rates for efficient treatment of net alkaline mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, C.S.; Dennis, A.; Kahler, A. [Bucknell University, Lewisburg, PA (United States). Dept. of Geology

    2009-07-15

    Passive treatment systems for mine drainage use no energy other than gravity, but they require greater area than active treatment systems. Researchers are considering 'hybrid' systems that have passive and active components for increased efficiency, especially where space limitations render passive-only technology ineffective. Flow-through reactor field experiments were conducted at two large net-alkaline anthracite mine discharges in central Pennsylvania. Assuming an Fe removal rate of 20 g m{sup -2} day{sup -1} and Fe loading from field data, 3.6 x 10{sup 3} and 3.0 x 10{sup 4} m{sup 2} oxidation ponds would be required for the passive treatment of Site 21 and Packer 5 discharges, respectively. However, only a small area is available at each site. This paper demonstrates aeration to drive off CO{sub 2}, increase pH, and increase Fe(II) oxidation rates, enabling treatment within a small area compared to passive treatment methods, and introduces a geochemical model to accurately predict these rates as well as semi-passive treatment system sizing parameters. Iron(II) oxidation modeling of actively aerated systems predicted that a 1-m deep pond with 10 times less area than estimated for passive treatment would lower Fe(II) concentrations to less than 1 mg L-1 at summer and winter temperatures for both sites. The use of active aeration for treatment Of CO{sub 2}-rich, net-alkaline discharges (including partially treated effluent from anoxic limestone drains) can result in considerably reduced treatment area for oxidation and may lower treatment costs, but settling of Fe hydroxides was not considered in this study. The reduced capital cost for earthmoving will need to be compared to energy and maintenance costs for aeration.

  15. Information v. energy efficiency incentives: Evidence from residential electricity consumption in Maryland

    International Nuclear Information System (INIS)

    Alberini, Anna; Towe, Charles

    2015-01-01

    We focus on two utility programs intended to reduce energy usage and the associated CO2 emissions—a home energy audit and rebates on the purchase of high-efficiency air-source heat pumps. We use a unique panel dataset from participating and non-participating households to estimate the average treatment effect of participating in either program on electricity usage. We fit models with household-by-season, season-by-year, and household-by-year fixed effects to account for all possible confounders that might influence energy usage. Since the programs are voluntary, we seek to restore near-exogeneity of the program “treatment” by matching participating households with control households. We deploy coarsened exact matching (CEM; Iacus et al., 2011) as our main matching method. We ask whether it is sufficient to match households based on past electricity usage, or if we gain by adding structural characteristics of the home, including heating system type. We find that the two programs reduce electricity usage by 5% on average. The effects are strong in both winter and summer for the energy audit groups but appear to be stronger in the winter for the heat pump rebate group. Adding house characteristics to the matching variables does seem to affect results, suggesting that using past usage alone, or house characteristics alone, may not be sufficient to identify the effects of program participation.

  16. Emission Impacts of Electric Vehicles in the US Transportation Sector Following Optimistic Cost and Efficiency Projections.

    Science.gov (United States)

    Keshavarzmohammadian, Azadeh; Henze, Daven K; Milford, Jana B

    2017-06-20

    This study investigates emission impacts of introducing inexpensive and efficient electric vehicles into the US light duty vehicle (LDV) sector. Scenarios are explored using the ANSWER-MARKAL model with a modified version of the Environmental Protection Agency's (EPA) 9-region database. Modified cost and performance projections for LDV technologies are adapted from the National Research Council (2013) optimistic case. Under our optimistic scenario (OPT) we find 15% and 47% adoption of battery electric vehicles (BEVs) in 2030 and 2050, respectively. In contrast, gasoline vehicles (ICEVs) remain dominant through 2050 in the EPA reference case (BAU). Compared to BAU, OPT gives 16% and 36% reductions in LDV greenhouse gas (GHG) emissions for 2030 and 2050, respectively, corresponding to 5% and 9% reductions in economy-wide emissions. Total nitrogen oxides, volatile organic compounds, and SO 2 emissions are similar in the two scenarios due to intersectoral shifts. Moderate, economy-wide GHG fees have little effect on GHG emissions from the LDV sector but are more effective in the electricity sector. In the OPT scenario, estimated well-to-wheels GHG emissions from full-size BEVs with 100-mile range are 62 gCO 2 -e mi -1 in 2050, while those from full-size ICEVs are 121 gCO 2 -e mi -1 .

  17. Trends of the electricity output, power conversion efficiency, and the grid emission factor in North Korea

    Science.gov (United States)

    Yeo, M. J.; Kim, Y. P.

    2017-12-01

    Recently, concerns about the atmospheric environmental problems in North Korea (NK) have been growing. According to the World Health Organization (WHO) (2017), NK was the first ranked country in mortality rate attributed to household and ambient air pollution in 2012. Reliable energy-related data in NK were needed to understand the characteristics of air quality in NK. However, data from the North Korean government were limited. Nevertheless, we could find specific energy-related data produced by NK in the Project Design Documents (PDDs) of the Clean Development Mechanism (CDM) submitted to the United Nations Framework Convention on Climate Change (UNFCCC). There were the 6 registered CDM projects hosted by North Korea, developed as small hydropower plants. Several data of each power plant, such as the electricity output, connected to the Eastern Power Grid (EPG) or the Western Power Grid (WPG) in North Korea were provided in the CDM PDDs. We (1) figured out the trends of the electricity output, the `power conversion efficiency' which we defined the amount of generated electricity to the supplied input primary energy for power generation, and fuel mix as grid emission factor in NK as using the data produced by NK between 2005 and 2009, (2) discussed the operating status of the thermal power plants in NK, and (3) discussed the energy/environmental-related policies and the priority issues in NK in this study.

  18. On the complex analysis of the reliability, safety, and economic efficiency of atomic electric power stations

    International Nuclear Information System (INIS)

    Emel'yanov, I.Ya.; Klemin, A.I.; Polyakov, E.F.

    1977-01-01

    The problem is posed of effectively increasing the engineering performance of nuclear electric power stations (APS). The principal components of the engineering performance of modern large APS are considered: economic efficiency, radiation safety, reliability, and their interrelationship. A nomenclature is proposed for the quantitative indices which most completely characterize the enumerated properties and are convenient for the analysis of the engineering performance. The urgent problem of developing a methodology for the complex analysis and optimization of the principal performance components is considered; this methodology is designed to increase the efficiency of the work on high-performance competitive APS. The principle of complex optimization of the reliability, safety, and economic-efficiency indices is formulated; specific recommendations are made for the practical realization of this principle. The structure of the complex quantiative analysis of the enumerated performance components is given. The urgency and promise of the complex approach to solving the problem of APS optimization is demonstrated, i.e., the solution of the problem of creating optimally reliable, fairly safe, and maximally economically efficient stations

  19. Analysis Platform for Energy Efficiency Enhancement in Hybrid and Full Electric Vehicles

    Directory of Open Access Journals (Sweden)

    NICOLAICA, M.-O.

    2016-02-01

    Full Text Available The current paper presents a new virtual analysis method that is applied both on hybrid and electric vehicle architectures with the purpose of contributing to the improvement of energy efficiency. The study is based on Matlab modeling and simulation. A set of parameters are considered in order to assess the system performance. The benefit is given by the comparative overview obtained after the completed analysis. The effectiveness of the analysis method is confirmed by a sequence of simulation results combined in several case studies. The impulse of the research is given by the fact that the automotive market is focusing on wider simulation techniques and better control strategies that lead to more efficient vehicles. Applying the proposed method during design would improve the battery management and controls strategy. The advantage of this method is that the system behavior with regards to energy efficiency can be evaluated from an early concept phase. The results contribute to the actual necessity of driving more efficient and more environmental friendly vehicles.

  20. System Efficiency Improvement for Electric Vehicles Adopting a Permanent Magnet Synchronous Motor Direct Drive System

    Directory of Open Access Journals (Sweden)

    Chengming Zhang

    2017-12-01

    Full Text Available To improve the endurance mileage of electric vehicles (EVs, it is important to decrease the energy consumption of the Permanent Magnet Synchronous Motor (PMSM drive system. This paper proposes a novel loss optimization control strategy named system efficiency improvement control which can optimize both inverter and motor losses. A nonlinear power converter loss model is built to fit the nonlinear characteristics of power devices. This paper uses double Fourier integral analysis to analytically calculate the fundamental and harmonic components of motor current by which the fundamental motor loss and harmonic motor loss can be accurately analyzed. From these loss models, a whole-frequency-domain system loss model is derived and presented. Based on the system loss model, the system efficiency improvement control method applies the genetic algorithm to adjust the motor current and PWM frequency together to optimize the inverter and motor losses by which the system efficiency can be significantly improved without seriously influence on the system stability over the whole operation range of EVs. The optimal effects of system efficiency is verified by the experimental results in both Si-IGBT-based PMSM system and SiC-MOSFET-based system.

  1. Financial impact of energy efficiency under a federal combined efficiency and renewable electricity standard: Case study of a Kansas 'super-utility'

    International Nuclear Information System (INIS)

    Cappers, Peter; Goldman, Charles

    2010-01-01

    Historically, local, state and federal policies have separately promoted the generation of electricity from renewable technologies and the pursuit of energy efficiency to help mitigate the detrimental effects of global climate change and foster energy independence. Federal policymakers are currently considering and several states have enacted a combined efficiency and renewable electricity standard which proponents argue provides a comprehensive approach with greater flexibility and at lower cost. We examine the financial impacts on various stakeholders from alternative compliance strategies with a Combined Efficiency and Renewable Electricity Standard (CERES) using a case study approach for utilities in Kansas. Our results suggest that an investor-owned utility is likely to pursue the most lucrative compliance strategy for its shareholders-one that under-invests in energy efficiency resources. If a business model for energy efficiency inclusive of both a lost fixed cost recovery mechanism and a shareholder incentive mechanism is implemented, our analysis indicates that an investor-owned utility would be more willing to pursue energy efficiency as a lower-cost CERES compliance strategy. Absent implementing such a regulatory mechanism, separate energy efficiency and renewable portfolio standards would improve the likelihood of reducing reliance on fossil fuels at least-cost through the increased pursuit of energy efficiency.

  2. The enhanced efficiency of graphene-silicon solar cells by electric field doping.

    Science.gov (United States)

    Yu, Xuegong; Yang, Lifei; Lv, Qingmin; Xu, Mingsheng; Chen, Hongzheng; Yang, Deren

    2015-04-28

    The graphene-silicon (Gr-Si) Schottky junction solar cell has been recognized as one of the most low-cost candidates in photovoltaics due to its simple fabrication process. However, the low Gr-Si Schottky barrier height largely limits the power conversion efficiency of Gr-Si solar cells. Here, we demonstrate that electric field doping can be used to tune the work function of a Gr film and therefore improve the photovoltaic performance of the Gr-Si solar cell effectively. The electric field doping effects can be achieved either by connecting the Gr-Si solar cell to an external power supply or by polarizing a ferroelectric polymer layer integrated in the Gr-Si solar cell. Exploration of both of the device architecture designs showed that the power conversion efficiency of Gr-Si solar cells is more than twice of the control Gr-Si solar cells. Our study opens a new avenue for improving the performance of Gr-Si solar cells.

  3. Investigation of Unequal Planar Wireless Electricity Device for Efficient Wireless Power Transfer

    Directory of Open Access Journals (Sweden)

    M. H. Mohd Salleh

    2017-04-01

    Full Text Available This article focuses on the design and investigation of a pair of unequally sized wireless electricity (Witricity devices that are equipped with integrated planar coil strips. The proposed pair of devices consists of two different square-shaped resonator sizes of 120 mm × 120 mm and 80 mm × 80 mm, acting as a transmitter and receiver, respectively. The devices are designed, simulated and optimized using the CST Microwave Studio software prior to being fabricated and verified using a vector network analyzer (VNA. The surface current results of the coupled devices indicate a good current density at 10 mm to 30 mm distance range. This good current density demonstrates that the coupled devices’ surface has more electric current per unit area, which leads to a good performance up to 30 mm range. Hence, the results also reveal good coupling efficiency between the coupled devices, which is approximately 54.5% at up to a 30 mm distance, with both devices axially aligned. In addition, a coupling efficiency of 50% is achieved when a maximum lateral misalignment (LM of 10 mm, and a varied angular misalignment (AM from 0° to 40° are implemented to the proposed device.

  4. Engine-integrated solid oxide fuel cells for efficient electrical power generation on aircraft

    Science.gov (United States)

    Waters, Daniel F.; Cadou, Christopher P.

    2015-06-01

    This work investigates the use of engine-integrated catalytic partial oxidation (CPOx) reactors and solid oxide fuel cells (SOFCs) to reduce fuel burn in vehicles with large electrical loads like sensor-laden unmanned air vehicles. Thermodynamic models of SOFCs, CPOx reactors, and three gas turbine (GT) engine types (turbojet, combined exhaust turbofan, separate exhaust turbofan) are developed and checked against relevant data and source material. Fuel efficiency is increased by 4% and 8% in the 50 kW and 90 kW separate exhaust turbofan systems respectively at only modest cost in specific power (8% and 13% reductions respectively). Similar results are achieved in other engine types. An additional benefit of hybridization is the ability to provide more electric power (factors of 3 or more in some cases) than generator-based systems before encountering turbine inlet temperature limits. A sensitivity analysis shows that the most important parameters affecting the system's performance are operating voltage, percent fuel oxidation, and SOFC assembly air flows. Taken together, this study shows that it is possible to create a GT-SOFC hybrid where the GT mitigates balance of plant losses and the SOFC raises overall system efficiency. The result is a synergistic system with better overall performance than stand-alone components.

  5. An electrically driven cavity-enhanced source of indistinguishable photons with 61% overall efficiency

    Directory of Open Access Journals (Sweden)

    A. Schlehahn

    2016-04-01

    Full Text Available We report on an electrically driven efficient source of indistinguishable photons operated at pulse-repetition rates f up to 1.2 GHz. The quantum light source is based on a p-i-n-doped micropillar cavity with integrated self-organized quantum dots, which exploits cavity quantum electrodynamics effects in the weak coupling regime to enhance the emission of a single quantum emitter coupled to the cavity mode. We achieve an overall single-photon extraction efficiency of (61 ± 11 % for a device triggered electrically at f = 625 MHz. Analyzing the suppression of multi-photon emission events as a function of excitation repetition rate, we observe single-photon emission associated with g(2HBT(0 values between 0.076 and 0.227 for f ranging from 373 MHz to 1.2 GHz. Hong-Ou-Mandel-type two-photon interference experiments under pulsed current injection at 487 MHz reveal a photon-indistinguishability of (41.1 ± 9.5 % at a single-photon emission rate of (92 ± 23 MHz.

  6. Low-Cost Energy-Efficient 3-D Nano-Spikes-Based Electric Cell Lysis Chips

    KAUST Repository

    Riaz, Kashif

    2017-05-04

    Electric cell lysis (ECL) is a promising technique to be integrated with portable lab-on-a-chip without lysing agent due to its simplicity and fast processing. ECL is usually limited by the requirements of high power/voltage and costly fabrication. In this paper, we present low-cost 3-D nano-spikes-based ECL (NSP-ECL) chips for efficient cell lysis at low power consumption. Highly ordered High-Aspect-Ratio (HAR). NSP arrays with controllable dimensions were fabricated on commercial aluminum foils through scalable and electrochemical anodization and etching. The optimized multiple pulse protocols with minimized undesirable electrochemical reactions (gas and bubble generation), common on micro parallel-plate ECL chips. Due to the scalability of fabrication process, 3-D NSPs were fabricated on small chips as well as on 4-in wafers. Phase diagram was constructed by defining critical electric field to induce cell lysis and for cell lysis saturation Esat to define non-ECL and ECL regions for different pulse parameters. NSP-ECL chips have achieved excellent cell lysis efficiencies ηlysis (ca 100%) at low applied voltages (2 V), 2~3 orders of magnitude lower than that of conventional systems. The energy consumption of NSP-ECL chips was 0.5-2 mJ/mL, 3~9 orders of magnitude lower as compared with the other methods (5J/mL-540kJ/mL). [2016-0305

  7. Using supervised environmental composites in production and efficiency analyses. An application to Norwegian electricity networks

    Energy Technology Data Exchange (ETDEWEB)

    Orea, Luis [Oviedo Univ. (Spain). Oviedo Efficiency Group; Growitsch, Christian [Koeln Univ. (Germany). Energiewirtschaftliches Inst.; Jamasb, Tooraj [Heriot-Watt Univ., Edinburgh (United Kingdom). Dept. of Economics

    2012-12-15

    Supervised dimension reduction methods have been extensively applied in different scientific fields like biology and medicine in recent years. However, they have hardly ever been used in micro economics, and in particular cost function modeling. Nonetheless, these methods can also be useful in regulation of natural monopolies such as gas, water, and electricity networks, where firms' cost and performance can be affected by a large number of environmental factors. In order to deal with this 'dimensionality' problem we propose using a supervised dimension reduction approach that aims to reduce the dimension of data without loss of information. Economic theory suggests that in the presence of other relevant production (cost) drivers, the traditional all-inclusive assumption is not satisfied and, hence, production or cost predictions (and efficiency estimates) might be biased. This paper shows that purging the data using a partial regression approach allows us to address this issue when analyzing the effect of weather and geography on cost efficiency in the context of the Norwegian electricity distribution networks.

  8. Efficient design of multituned transmission line NMR probes: the electrical engineering approach.

    Science.gov (United States)

    Frydel, J A; Krzystyniak, M; Pienkowski, D; Pietrzak, M; de Sousa Amadeu, N; Ratajczyk, T; Idzik, K; Gutmann, T; Tietze, D; Voigt, S; Fenn, A; Limbach, H H; Buntkowsky, G

    2011-01-01

    Transmission line-based multi-channel solid state NMR probes have many advantages regarding the cost of construction, number of RF-channels, and achievable RF-power levels. Nevertheless, these probes are only rarely employed in solid state-NMR-labs, mainly owing to the difficult experimental determination of the necessary RF-parameters. Here, the efficient design of multi-channel solid state MAS-NMR probes employing transmission line theory and modern techniques of electrical engineering is presented. As technical realization a five-channel ((1)H, (31)P, (13)C, (2)H and (15)N) probe for operation at 7 Tesla is described. This very cost efficient design goal is a multi port single coil transmission line probe based on the design developed by Schaefer and McKay. The electrical performance of the probe is determined by measuring of Scattering matrix parameters (S-parameters) in particular input/output ports. These parameters are compared to the calculated parameters of the design employing the S-matrix formalism. It is shown that the S-matrix formalism provides an excellent tool for examination of transmission line probes and thus the tool for a rational design of these probes. On the other hand, the resulting design provides excellent electrical performance. From a point of view of Nuclear Magnetic Resonance (NMR), calibration spectra of particular ports (channels) are of great importance. The estimation of the π/2 pulses length for all five NMR channels is presented. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. The impact of wind forecast errors on the efficiency of the Ontario electricity market

    International Nuclear Information System (INIS)

    Ng, H.

    2008-01-01

    Ontario's Independent System Operator (IESO) is currently involved in a number of wind projects in the province, and has developed both a resource commitment and dispatch timeline in relation to increased wind power penetration in the Ontario electricity grid. This presentation discussed the impacts of wind forecast errors on the province's electricity market. Day-ahead planning is used to commit fossil fuels and gas resources, while 3-hours ahead planning is used to commit generation in real time. Inter-ties are committed 1 hour ahead of dispatch. Over-forecasts for wind can cause market prices to increase in real-time, or cause markets to miss opportunities to schedule cheaper imports. The inefficient scheduling caused by overforecasts can also lead to exports not being purchases at high enough prices. Under-forecasts can cause market prices to decrease, and may cause imports to be scheduled that would not have been economic at lower prices. The scheduling difficulties related to under-forecasting can cause markets to miss opportunities to schedule efficient exports. Wind facility forecast errors typically improve closer to real-time. One-hour ahead wind forecast errors can reach approximately 12 per cent. The annual costs of overforecasting are under $200,000. Underforecasting costs are usually less than $30,000. The costs of the wind forecasting inefficiencies are relatively small in the $10 billion electricity market. It was concluded that system operators will continue to track forecast errors and inefficiencies as wind power capacity in the electric power industry increases. tabs., figs

  10. Efficient wireless power charging of electric vehicle by modifying the magnetic characteristics of the medium

    Science.gov (United States)

    Mahmud, Mohammad Hazzaz

    There is a developing enthusiasm for electric vehicle (EV) innovations as a result of their lessened fuel utilization and greenhouse emission especially through wireless power transfer (WPT) due to the convenience and continuous charging. Numerous research initiatives target on wireless power transfer (WPT) system in the attempt to improve the transportation for last few decades. But several problems like less efficiency, high frequency, long distance energy transfer etc. were always been occupied by the wireless power transfer system. Two ideas have been developed in this research to resolve the two main problems of WPT for electric vehicles which are low efficiency due to large distance between the two coils and slow charging time. As the first phase of study, a proper model, including the coils and cores were required. The selected model was a finite element (FE) modeling. Another part of this study was to create a modified cement that will act as a semi-conductive material for covering the transmitting antenna area. A high frequency wide band gap switch will be used for transferring high amount of power in a very short time. More over this research also proves that, if cores could be added with the transmitter coil and receiver coil then the output efficiency dramatically increased comparing with without core model of transmitter and receiver. The wireless charging is not restricted to parking lot, since it's planned to be embedded into parking space concrete or roadway concrete or asphalt. Therefore, it can also be installed at junctions (behind red lights), stop signs or any spot that the vehicle might stop for several moments. This technology will become more feasible, if the charging time decreases. Therefore, a new model of for wireless power transfer has been proposed in this study which has shown significant improvement. Another motive of this study was to improve the conductivity and permeability in such a way that the medium that is on the top of the

  11. Efficiency and productivity (TFP) of the Turkish electricity distribution companies: An application of two-stage (DEA and Tobit) analysis

    International Nuclear Information System (INIS)

    Çelen, Aydın

    2013-01-01

    In this study, we analyze the efficiency performances of 21 Turkish electricity distribution companies during the period of 2002–2009. For this aim, we employ a two-stage analysis in order to take into account the business environment variables which are beyond the control of distribution companies. We determine the efficiency performances of the electricity distribution companies by help of DEA in the first stage. Then, in the second stage, using these calculated efficiency scores as dependent variable, we utilize Tobit model to determine the business environment variables which may explain the efficiency scores. According to the results, customer density of the region and the private ownership affect the efficiencies positively. Thus, the best strategy to improve efficiency in the market is privatizing the public distribution companies. - Highlights: • We analyze the efficiencies of 21 Turkish electricity distribution companies. • A two-stage analysis is employed to take into account environmental variables. • We firstly calculate efficiencies of companies with DEA, then Tobit model is used to determine the effects of the variables. • Customer density and ownership type affect the efficiencies positively. • Privatization is a good strategy to improve efficiencies

  12. Increasing coal-fired power generation efficiency to reduce electric cost and environmental emissions

    International Nuclear Information System (INIS)

    Torrens, I.M.; Stenzel, W.C.

    1997-01-01

    New generating capacity required globally between 1993 and 2010 is estimated to be around 1500 GW, of which some two-thirds will be outside the OECD, and some 40 % in the Asian non-OECD countries. Coal is likely to account for a substantial fraction of this new generation. Today's state-of-the-art supercritical coal-fired power plant has a conversion efficiency of some 42-45 %. The capital cost increase associated with the supercritical or ultra-supercritical pulverized coal power plant compared to a conventional subcritical plant is small to negligible. The increased efficiency associated with the supercritical plant leads to an actual reduction in the total cost of electricity generated in cents/kWh, relative to a conventional plant. Despite this, the power sector continues to build subcritical plants and has no near term plans to increase the efficiency of power plants in the projects it is developing. Advanced clean coal technologies such as integrated gasification combined cycle and pressurized fluidized bed combustion will be selected for independent power projects only in very specific circumstances. Advanced clean coal plants can be operated reliably and with superior performance, and specifically that their present estimated capital costs can be reduced substantially to a point where they are competitive with state-of-the-art pulverized coal technologies. (R.P.)

  13. A Proportional Resonant Control Strategy for Efficiency Improvement in Extended Range Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Xiaoyuan Wang

    2017-02-01

    Full Text Available The key to control the range extender generation system is to improve the efficiency and reduce the emissions of the electric vehicle (EV. In this paper, based on the purpose of efficiency optimization, both engine and generator are matched to get a public high efficiency region, and a partial power following control strategy was presented. The engine speed is constant in the defined power range, so the output power regulation of the range extender is only realized by the adjustment of the torque of the generator. Engine speed and generator torque were decoupled. An improved proportional resonant (PR controller is adopted to achieve fast output power regulation. In order to ensure the response characteristics of the control system and to improve the robustness, the impacts on system’s characteristics and stability caused by PR controller and parameters in the inner-current loop were analyzed via frequency response characteristics. A pre-Tustin with deviation compensation is proposed for PR controller’s discretization. A stable and robust power following control method is obtained for the range extender control system. Finally, simulation and experiment of the proposed control strategy illustrated its feasibility and correctness.

  14. Energy efficiency improvement procedures and audit results of electrical, thermal and solar applications in Palestine

    International Nuclear Information System (INIS)

    Ibrik, I.H.; Mahmoud, M.M.

    2005-01-01

    Energy conservation in utilities has played a vital role in improving energy efficiency in the industrial, commercial and residential sectors. The electrical energy consumption in Palestine has increased sharply in the past few years and achieved by the end of 2001 to 10% per year. It is expected that this percentage will increase to about 12% if the current political situation will end hopefully with peace. Modern energy efficient technologies are needed for the national energy policy. Such technologies are investigated in this paper. Implementing of a national 3 years project aiming at energy efficiency improvement in residential and industrial sectors as well as in public utilities, which include wide range of diversified audits and power measurements, had led to creating this paper. Measurement and audit results had shown that the total conservation potential in these sectors is around 15% of the total energy consumption. The associated costs of the investment in this field are relatively low and correspond to a pay back period varying in the range from 6 to 36 months. Consequently, the energy conservation policy will be seriously improved in the forthcoming years. It is estimated that 10% of the new energy purchasing capacity will be reduced accordingly

  15. Stepwise data envelopment analysis (DEA); choosing variables for measuring technical efficiency in Norwegian electricity distribution

    International Nuclear Information System (INIS)

    Kittelsen, S.A.C.

    1993-04-01

    Electric power distribution is an activity that in principle delivers a separate product to each customer. A specification of products for a utility as a whole leads potentially to a large number of product aspects including topographic and climatic conditions, and the level of disaggregation of factors and products may give the production and cost functions a high dimensionality. Some aggregation is therefore necessary. Non-parametric methods like Data Envelopment Analysis (DEA) have the advantage that they may give meaningful results when parametric methods would not have enough degrees of freedom, but will have related problems if the variables are collinear or are irrelevant. Although aggregate efficiency measures will not be much affected, rates of transformation will be corrupted and observations with extreme values may be measured as efficient by default. Little work has been done so far on the statistical properties of the non-parametric efficiency measure. This paper utilizes a suggestion by Rajiv Banker to measure the significance of the change in results when disaggregating or introducing an extra variable, and shows how one can let the data participate in deciding which variables should be included in the analysis. 32 refs., 7 figs., 4 tabs

  16. Increasing the electric efficiency of a fuel cell system by recirculating the anodic offgas

    Science.gov (United States)

    Heinzel, A.; Roes, J.; Brandt, H.

    The University of Duisburg-Essen and the Center for Fuel Cell Technology (ZBT Duisburg GmbH) have developed a compact multi-fuel steam reformer suitable for natural gas, propane and butane. Fuel processor prototypes based on this concept were built up in the power range from 2.5 to 12.5 kW thermal hydrogen power for different applications and different industrial partners. The fuel processor concept contains all the necessary elements, a prereformer step, a primary reformer, water gas shift reactors, a steam generator, internal heat exchangers, in order to achieve an optimised heat integration and an external burner for heat supply as well as a preferential oxidation step (PrOx) as CO purification. One of the built fuel processors is designed to deliver a thermal hydrogen power output of 2.5 kW according to a PEM fuel cell stack providing about 1 kW electrical power and achieves a thermal efficiency of about 75% (LHV basis after PrOx), while the CO content of the product gas is below 20 ppm. This steam reformer has been combined with a 1 kW PEM fuel cell. Recirculating the anodic offgas results in a significant efficiency increase for the fuel processor. The gross efficiency of the combined system was already clearly above 30% during the first tests. Further improvements are currently investigated and developed at the ZBT.

  17. Organizational human factors as barriers to energy efficiency in electrical motors systems in industry

    International Nuclear Information System (INIS)

    Sola, Antonio Vanderley Herrero; Augusto de Paula, Xavier Antonio

    2007-01-01

    This paper presents a study accomplished in the State of Parana in Southern Brazil, aiming at verifying the correlation between organizational human factors (OHF) and the level of energy losses in organizations. The purpose is to subsidize the formularization of institutional policies in organizations to improve the energy efficiency in the productive sector. The research was carried out in ten industries of the following sectors: pulp and paper; food; wood and chemical products. The losses of electric energy were determined in motor systems with the aid of a mathematical model and the evaluation of 27 OHF identified in the literature review was made with the supervisors in the industries by means of a structurized questionnaire. Seven OHF had presented significant correlation with energy losses and six of them are inversely proportional to the losses, in accordance with linear regression analysis. The inversely proportional factors to the losses also with significant correlation are considered determinative OHF and constitute barriers for energy efficiency in organizations. These barriers are linked with the following organizational areas: management system; education of employees; strategical vision. The study recommends the implementation of the determinative OHF in organizations as a way to transpose the human barriers for energy efficiency

  18. Cutting efficiency of diamond burs operated with electric high-speed dental handpiece on zirconia.

    Science.gov (United States)

    Nakamura, Keisuke; Katsuda, Yusuke; Ankyu, Shuhei; Harada, Akio; Tenkumo, Taichi; Kanno, Taro; Niwano, Yoshimi; Egusa, Hiroshi; Milleding, Percy; Örtengren, Ulf

    2015-10-01

    Zirconia-based dental restorations are becoming used more commonly. However, limited attention has been given to the difficulties experienced, concerning cutting, in removing the restorations when needed. The aim of the present study was to compare the cutting efficiency of diamond burs, operated using an electric high-speed dental handpiece, on zirconia (Zir) with those on lithium disilicate glass-ceramic (LD) and leucite glass-ceramic (L). In addition, evaluation of the cutting efficiency of diamond burs on Zir of different thicknesses was performed. Specimens of Zir were prepared with thicknesses of 0.5, 1.0, 2.0, and 4.0 mm, and specimens of LD and L were prepared with a thickness of 1.0 mm. Cutting tests were performed using diamond burs with super coarse (SC) and coarse (C) grains. The handpiece was operated at 150,000 rpm with a cutting force of 0.9 N. The results demonstrated that cutting of Zir took about 1.5- and 7-fold longer than cutting of LD and L, respectively. The SC grains showed significantly higher cutting efficiency on Zir than the C grains. However, when the thickness of Zir increased, the cutting depth was significantly decreased. As it is suggested that cutting of zirconia is time consuming, this should be taken into consideration in advance when working with zirconia restorations. © 2015 Eur J Oral Sci.

  19. Study Of Higher Moments Of Net-Electric Charge & Net-Proton Number Fluctuations In Pb+Pb Collisions At $\\sqrt{s_{NN}}$=2.76 TeV In ALICE At LHC

    CERN Document Server

    Behera, Nirbhay Kumar

    Lattice QCD predicts that at extreme temperature and energy density, QCD matter will undergo a phase transition from hadronic matter to partonic matter called as QGP. One of the fundamental goals of heavy ion collision experiments to map the QCD phase diagram as a function of temperature (T) and baryo-chemical potential ($\\mu_{B}$). There are many proposed experimental signatures of QGP and fluctuations study are regarded as sensitive tool for it. It is proposed that fluctuation of conserved quantities like net-charge and net-proton can be used to map the QCD phase diagram. The mean ($\\mu$), sigma ($\\sigma$), skewness (S) and kurtosis ($\\kappa$) of the distribution of net charge and net proton are believed to be sensitive probes in fluctuation analysis. It has been argued that critical phenomena are signaled with increase and divergence of correlation length. The dependence of $n^{th}$ order higher moments (cumulants, $c_{n}$) with the correlation length $\\xi$ is as $c_{n}\\sim\\xi^{2.5n-3}$. At LHC energy, the...

  20. Canopy uptake of atmospheric N deposition at a conifer forest: part I -canopy N budget, photosynthetic efficiency and net ecosystem exchange

    International Nuclear Information System (INIS)

    Sievering, H.; Tomaszewski, T.; Torizzo, J.

    2007-01-01

    Global carbon cycle assessments of anthropogenic nitrogen (N) deposition influences on carbon sequestration often assume enhanced sequestration results. This assumption was evaluated at a Rocky Mountains spruce-fir forest. Forest canopy N uptake (CNU) of atmospheric N deposition was estimated by combining event wet and throughfall N fluxes with gradient measured HNO 3 and NH 3 as well as inferred (NO x and particulate N) dry fluxes. Approximately 80% of the growing-season 3 kg N/ha total deposition is retained in canopy foliage and branches. This CNU constitutes ∼1/3 of canopy growing season new N supply at this conifer forest site. Daytime net ecosystem exchange (NEE) significantly (P = 0.006) and negatively (CO 2 uptake) correlated with CNU. Multiple regression indicates ∼20% of daytime NEE may be attributed to CNU (P < 0.02); more than soil water content. A wet deposition N-amendment study (Tomaszewski and Sievering), at canopy spruce branches, increased their growing-season CNU by 40-50% above ambient. Fluorometry and gas exchange results show N-amended spruce branches had greater photosynthetic efficiency and higher carboxylation rates than control and untreated branches. N-amended branches had 25% less photoinhibition, with a 5-9% greater proportion of foliar-N-in-Rubisco. The combined results provide, partly, a mechanistic explanation for the NEE dependence on CNU

  1. RESTful NET

    CERN Document Server

    Flanders, Jon

    2008-01-01

    RESTful .NET is the first book that teaches Windows developers to build RESTful web services using the latest Microsoft tools. Written by Windows Communication Foundation (WFC) expert Jon Flanders, this hands-on tutorial demonstrates how you can use WCF and other components of the .NET 3.5 Framework to build, deploy and use REST-based web services in a variety of application scenarios. RESTful architecture offers a simpler approach to building web services than SOAP, SOA, and the cumbersome WS- stack. And WCF has proven to be a flexible technology for building distributed systems not necessa

  2. Improved netting

    International Nuclear Information System (INIS)

    Bramley, A.; Clabburn, R.J.T.

    1976-01-01

    A method is described for producing netting composed of longitudinal and transverse threads of irradiation cross linked thermoplastic material, the threads being joined together at their crossings by moulded masses of cross linked thermoplastic material. The thread may be formed of polyethylene filaments, subjected to a radiation dose of 15 to 25 MR. The moulding can be conducted at 245 0 to 260 0 C or higher. The product is claimed to be an improved quality of netting, with bonds of increased strength between crossing threads. (U.K.)

  3. ENERGY EFFICIENCY OF ELECTRIC HEATING OF REACTORS IN THE MANUFACTURE OF VARNISHES AND PAINTS

    Directory of Open Access Journals (Sweden)

    Tovajniansky L.L.

    2014-08-01

    Full Text Available The drawbacks of the traditional design of the heaters, which make known imperfections in manufacturing processes, realized with the use of electric heating. This determines the need for a radically new design of the heating devices. Created by high-temperature ceramics, characterized by abnormally high thermal stability and clarified the parameters that allow a certain degree change its thermal conductivity. On this basis the contact type ceramic heaters that provide thermal flow direction using different materials in the body of the heater - of high thermal conductivity, the surface facing the heat transfer and low which differs opposite sides of the heater are designed to eliminate the dissipation of heat into the surrounding space. This made it possible to equip the modern production paint industry energy efficient heating equipment with explosion and fire heating system reactors.

  4. Real-time control strategy to maximize hybrid electric vehicle powertrain efficiency

    International Nuclear Information System (INIS)

    Shabbir, Wassif; Evangelou, Simos A.

    2014-01-01

    Highlights: • An off-line local control is proposed for real-time HEV energy management. • Powertrain efficiencies are studied to produce a unified objective function. • Penalty function is designed to ensure charge sustaining operation. • Implementation by storing optimal power share in a two-dimensional control map. • Proposed control improved fuel economy by up to 20% compared to conventional control. - Abstract: The proposed supervisory control system (SCS) uses a control map to maximize the powertrain efficiency of a hybrid electric vehicle (HEV) in real-time. The paper presents the methodology and structure of the control, including a novel, comprehensive and unified expression for the overall powertrain efficiency that considers the engine-generator set and the battery in depth as well as the power electronics. A control map is then produced with instructions for the optimal power share between the engine branch and battery branch of the vehicle such that the powertrain efficiency is maximized. This map is computed off-line and can thereafter be operated in real-time at very low computational cost. A charge sustaining factor is also developed and introduced to ensure the SCS operates the vehicle within desired SOC bounds. This SCS is then tested and benchmarked against two conventional control strategies in a high-fidelity vehicle model, representing a series HEV. Extensive simulation results are presented for repeated cycles of a diverse range of standard driving cycles, showing significant improvements in fuel economy (up to 20%) and less aggressive use of the battery

  5. Contract market power and its impact on the efficiency of the electricity sector

    International Nuclear Information System (INIS)

    Serra, Pablo

    2013-01-01

    This paper analyzes the pro-competitive effects of financial long-term contracts in oligopolistic electricity markets. This is done in a model that incorporates the main features of the industry: non-storable production, time-varying price-elastic demand, and sequential investment and production decisions. The paper considers contracts for difference that have as reference price the average spot price. Assuming that the spot market coordinator sets competitive prices, the paper shows that installed capacity increases with the quantity of energy contracted, reaching the welfare-maximizing capacity when energy contracted equals this same level. Next, the paper studies the case where the quantity of energy contracted is endogenous and contracts are traded before capacity decisions are taken. Regarding purchasers of contracts, two polar cases are considered: either they are price-taker speculators or they are an aggregation of consumers that auctions a long (buy) contract for a given energy quantity. In the former case the strike price equals the reference price, i.e., arbitrage is perfect, and the quantity of energy contracted falls short of the efficient level. In turn, in the latter case, the strike price equals the average efficient spot price. Moreover, an aggregation of all consumers would choose to auction the social optimum quantity. - Highlights: • The paper analyzes the pro-competitive impact of contracts for difference. • The reference price of contracts is the average spot price. • Installed capacity increases with total quantity of energy contracted. • Social welfare is maximized when energy contracted equals the efficient capacity. • An aggregation of all consumers would choose to auction the efficient quantity

  6. Charge collection efficiency in a semiconductor radiation detector with a non-constant electric field

    International Nuclear Information System (INIS)

    Shah, K.S.; Lund, J.C.; Olschner, F.

    1990-01-01

    The development of improved semiconductor radiation detectors would be facilitated by a quantitative model that predicts the performance of these detectors as a function of material characteristics and device operating parameters. An accurate prediction of the pulse height spectrum from a radiation detector can be made if both the noise and the charge collection properties of the detector are understood. The noise characteristics of semiconductor radiation detectors have been extensively studied. The effect of noise can be closely simulated by convoluting the noise-free pulse height spectrum with a Gaussian function. Distortion of semiconductor detector's pulse height spectrum from charge collection effects is more complex than the effects of noise and is more difficult to predict. To compute these distortions it is necessary to know how the charge collection efficiency η varies as a function of position within the detector x. These effects are shown. This problem has been previously solved for planar detectors with a constant electric field, for the case of spherical detectors, and for coaxial detectors. In this paper the authors describe a more general solution to the charge collection problem which includes the case of a non-constant electric field in a planar geometry

  7. [Efficiency of oxidant gas generator cells powered by electric or solar energy].

    Science.gov (United States)

    Brust Carmona, H; Benitez, A; Zarco, J; Sánchez, E; Mascher, I

    1998-02-01

    Diseases caused by microbial contaminants in drinking water continue to be a serious problem in countries like Mexico. Chlorination, using chlorine gas or chlorine compounds, is one of the best ways to treat drinking water. However, difficulties in handling chlorine gas and the inefficiency of hypochlorite solution dosing systems--due to sociopolitical, economic, and cultural factors--have reduced the utility of these chlorination procedures, especially in far-flung and inaccessible rural communities. These problems led to the development of appropriate technologies for the disinfection of water by means of the on-site generation of mixed oxidant gases (chlorine and ozone). This system, called MOGGOD, operates through the electrolysis of a common salt solution. Simulated system evaluation using a hydraulic model allowed partial and total costs to be calculated. When powered by electrical energy from the community power grid, the system had an efficiency of 90%, and in 10 hours it was able to generate enough gases to disinfect about 200 m3 of water at a cost of approximately N$8 (US $1.30). When the electrolytic cell was run on energy supplied through a photoelectric cell, the investment costs were higher. A system fed by photovoltaic cells could be justified in isolated communities that lack electricity but have a gravity-fed water distribution system.

  8. Analytical framework for analyzing the energy conversion efficiency of different hybrid electric vehicle topologies

    International Nuclear Information System (INIS)

    Katrasnik, Tomaz

    2009-01-01

    Energy consumption and exhaust emissions of hybrid electric vehicles (HEVs) strongly depend on the HEV topology, power ratios of the components and applied control strategy. There are many available patterns of combining the power flows to meet load requirements making it difficult to analyze and evaluate a newly designed HEV. In order to enhance design of HEVs, the paper provides a stand alone analytical framework for evaluating energy conversion phenomena of different HEV topologies. Analytical analysis is based on the energy balance equations and considers the complete energy path in the HEVs from the energy sources to the wheels and to other energy sinks. The analytical framework enables structuring large amount of data in physically meaningful energy flows and associated energy losses, and therefore provides insightful information for HEV optimization. It therefore enables identification of most suitable HEV topology and of most suitable power ratios of the components, since it reveals and quantifies the instruments that could lead to improved energy conversion efficiency of particular HEV. The analytical framework is also applicable for correcting the energy consumption of the HEV to the value corresponding to balanced energy content of the electric storage devices.

  9. Magnesium and Manganese Silicides For Efficient And Low Cost Thermo-Electric Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Trivedi, Sudhir B. [Brimrose Technology Corporation; Kutcher, Susan W. [Brimrose Technology Corporation; Rosemeier, Cory A. [Brimrose Technology Corporation; Mayers, David [Brimrose Technology Corporation; Singh, Jogender [Pennsylvania State University

    2013-12-02

    Thermoelectric Power Generation (TEPG) is the most efficient and commercially deployable power generation technology for harvesting wasted heat from such things as automobile exhausts, industrial furnaces, and incinerators, and converting it into usable electrical power. We investigated the materials magnesium silicide (Mg2Si) and manganese silicide (MnSi) for TEG. MgSi2 and MnSi are environmentally friendly, have constituent elements that are abundant in the earth's crust, non-toxic, lighter and cheaper. In Phase I, we successfully produced Mg2Si and MnSi material with good TE properties. We developed a novel technique to synthesize Mg2Si with good crystalline quality, which is normally very difficult due to high Mg vapor pressure and its corrosive nature. We produced n-type Mg2Si and p-type MnSi nanocomposite pellets using FAST. Measurements of resistivity and voltage under a temperature gradient indicated a Seebeck coefficient of roughly 120 V/K on average per leg, which is quite respectable. Results indicated however, that issues related to bonding resulted in high resistivity contacts. Determining a bonding process and bonding material that can provide ohmic contact from room temperature to the operating temperature is an essential part of successful device fabrication. Work continues in the development of a process for reproducibly obtaining low resistance electrical contacts.

  10. Improved electrical efficiency and bottom ash quality on waste combustion plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Peter A.; Nesterov, I.; Boejer, M.; Hyks, J.; Astrup, T.; Kloeft, H.; Dam-Johansen, K.; Lundtorp, K.; Hedegaard Madsen, O.; Frandsen, F. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Mogensen, Erhardt (Babcock and Wilcox Voelund A/S, Glostrup (Denmark))

    2010-07-01

    Investigations making it possible to evaluate and further develop concepts to improve electrical efficiency in a waste combustion plant were performed. Furthermore, one objective of the study was to investigate the possibilities of improving waste bottom ash leaching properties by use of a rotary kiln treatment. The project work included construction of a bench-scale rotary kiln, performing ash rotary kiln treatment experiments, conducting gas suction probe measurements on a waste incineration plant and making some concept evaluations. The influence of the rotary kiln thermal treatment on the leaching of Ca, Al, Si, Mg, Ba, Sr, Cl, Cu, Pb, Zn, Cr, Mo, sulfate, DOC and carbonate was determined. As a result of these tests, the rotary kiln thermal treatment of bottom ashes can be recommended for reducing the leaching of Cu, Pb, Cl, Zn and DOC; however, an increased leaching of Cr and Mo should be expected. The combustion conditions above the grate of a waste incineration plant were investigated and the release and concentration of volatile ash species in the flue gas such as Cl, Na, K, Ca, Pb, Zn and S were measured. The conducted measurements show that flue gas from grate sections 3 and 4 can produce a sufficiently hot flue gas that contains only low concentrations of corrosive species, and therefore can be used to increase superheater temperatures. Implementation of the so-called flue gas split concept together with other steam circle modifications on a waste combustion plant, and using a reasonable increase in final steam temperature from 400 to 500 deg. C, have the potential to increase electrical efficiency from 24 to 30% (with respect to lower fuel heating value) in a waste combustion plant. (Author)

  11. Petri Nets

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 9. Petri Nets - Applications. Y Narahari. General Article Volume 4 Issue 9 September 1999 pp 44-52 ... Author Affiliations. Y Narahari1. Department of Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India.

  12. Net Gain

    International Development Research Centre (IDRC) Digital Library (Canada)

    Describing the effect of tax incentives for import, production, and sale of nets and insecticides; and ..... So far, China is the only country where a system for the routine treatment of ...... 1993), and the trials in Ecuador and Peru (Kroeger et al.

  13. Aeration to degas CO2, increase pH, and increase iron oxidation rates for efficient treatment of net alkaline mine drainage

    International Nuclear Information System (INIS)

    Kirby, C.S.; Dennis, A.; Kahler, A.

    2009-01-01

    Passive treatment systems for mine drainage use no energy other than gravity, but they require greater area than active treatment systems. Researchers are considering 'hybrid' systems that have passive and active components for increased efficiency, especially where space limitations render passive-only technology ineffective. Flow-through reactor field experiments were conducted at two large net-alkaline anthracite mine discharges in central Pennsylvania. Assuming an Fe removal rate of 20 g m -2 day -1 and Fe loading from field data, 3.6 x 10 3 and 3.0 x 10 4 m 2 oxidation ponds would be required for the passive treatment of Site 21 and Packer 5 discharges, respectively. However, only a small area is available at each site. This paper demonstrates aeration to drive off CO 2 , increase pH, and increase Fe(II) oxidation rates, enabling treatment within a small area compared to passive treatment methods, and introduces a geochemical model to accurately predict these rates as well as semi-passive treatment system sizing parameters. Both net-alkaline discharges were suboxic with a pH of ∼5.7, Fe(II) concentration of ∼16 mg L -1 , and low Mn and Al concentrations. Flow rates were ∼4000 L min -1 at Site 21 and 15,000 L min -1 at Packer 5. Three-h aeration experiments with flow rates scaled to a 14-L reactor resulted in pH increases from 5.7 to greater than 7, temperature increases from 12 to 22 deg. C, dissolved O 2 increases to saturation with respect to the atmosphere, and Fe(II) concentration decreases from 16 to -1 . A 17,000-L pilot-scale reactor at Site 21 produced similar results although aeration was not as complete as in the smaller reactor. Two non-aerated experiments at Site 21 with 13 and 25-h run times resulted in pH changes of ≤0.2 and Fe(II) concentration decreases of less than 3 mg L -1 . An Fe(II) oxidation model written in a differential equation solver matched the field experiments very well using field-measured pH, temperature, dissolved O 2

  14. ANALYSIS OF ENERGY EFFICIENCY OF OPERATING MODES OF ELECTRICAL SYSTEMS WITH THE TRACTION LOADS

    Directory of Open Access Journals (Sweden)

    V. E. Bondarenko

    2017-03-01

    Full Text Available Innovative scenarios of reliable energy supply of transportation process aimed at reducing the specific energy consumption and increase energy efficiency of the systems of electric traction. The paper suggests innovative energy saving directions in traction networks of railways and new circuit solutions accessing traction substations in energy systems networks, ensure energy security of the transportation process. To ensure the energy security of rail transport special schemes were developed to propose the concept of external power traction substations, which would increase the number of connections to the networks of 220 – 330 kV, as well as the creation of transport and energy corridors, development of its own supply of electric networks of 110 kV substations and mobile RP-110 kV of next generation. Therefore, the investment program of the structures owned by the Ukrainian Railways (Ukrzaliznytsia need to be synchronized in their technological characteristics, as well as the criteria of reliability and quality of power supply with the same external energy investment programs. It is found that without any load on left or right supplying arm one of two less loaded phases of traction transformer begins generating specific modes in the supplying three-phase line. Thus, modes of mobile substation cause leakage in one of the phases of the supply line of traction transformers of active-capacitive current, and as a result generating energy in the main power line of 154 kV, which is fixed and calculated by electricity meters. For these three phase mode supply network is necessary to use 1st algorithm, i.e. taking into account the amount of electricity as the energy in all phases. For effective application of reactive power compensation devices in the AC traction power supply systems it is proposed to develop regulatory documentation on necessity of application and the order of choice of parameters and placement of compensation systems taking into

  15. The performance and efficiency of four motor/controller/battery systems for the simpler electric vehicles

    Science.gov (United States)

    Shipps, P. R.

    1980-01-01

    A test and analysis program performed on four complete propulsion systems for an urban electric vehicle (EV) is described and results given. A dc series motor and a permanent magnet (PM) motor were tested, each powered by an EV battery pack and controlled by (1) a series/parallel voltage-switching (V-switch) system; and (2) a system using a pulse width modulation, 400 Hz transistorized chopper. Dynamometer tests were first performed, followed by eV performance predictions and data correlating road tests. During dynamometer tests using chopper control; current, voltage, and power were measured on both the battery and motor sides of the chopper, using three types of instrumentation. Conventional dc instruments provided adequate accuracy for eV power and energy measurements, when used on the battery side of the controller. When using the chopper controller, the addition of a small choke inductor improved system efficiency in the lower duty cycle range (some 8% increase at 50% duty cycle) with both types of motors. Overall system efficiency rankings during road tests were: (1) series motor with V-switch; (2) PM motor with V-switch; (3) series motor with chopper; and (4) PM motor with chopper. Chopper control of the eV was smoother and required less driver skill than V-switch control.

  16. Efficiency effects of quality of service and environmental factors. Experience from Norwegian electricity distribution

    Energy Technology Data Exchange (ETDEWEB)

    Growitsch, Christian [WIK Wissenschaftliches Institut fuer Infrastruktur und Kommunikationsdienste GmbH, Bad Honnef (Germany). Dept. of Energy Markets and Energy Regulation; Jamasb, Tooraj [Edinburgh Univ. (United Kingdom). Dept. of Economics; Wetzel, Heike [Cologne Univ. (Germany). Dept. of Economics

    2010-08-15

    Since the 1990s, efficiency and benchmarking analysis has increasingly been used in network utilities research and regulation. A recurrent concern is the effect of environmental factors that are beyond the influence of firms (observable heterogeneity) and factors that are not identifiable (unobserved heterogeneity) on measured cost and quality performance of firms. This paper analyses the effect of geographic and weather factors and unobserved heterogeneity on a set of 128 Norwegian electricity distribution utilities for the 2001-2004 period. We utilize data on almost 100 geographic and weather variables to identify real economic inefficiency while controlling for observable and unobserved heterogeneity. We use the factor analysis technique to reduce the number of environmental factors into few composite variables and to avoid the problem of multicollinearity. We then estimate the established stochastic frontier models of Battese and Coelli (1992; 1995) and the recent true fixed effects models of Greene (2004; 2005) without and with environmental variables. In the former models some composite environmental variables have a significant effect on the performance of utilities. These effects vanish in the true fixed effects models. However, the latter models capture the entire unobserved heterogeneity and therefore show significantly higher average efficiency scores. (orig.)

  17. Energy efficient non-road hybrid electric vehicles advanced modeling and control

    CERN Document Server

    Unger, Johannes; Jakubek, Stefan

    2016-01-01

    Analyzing the main problems in the real-time control of parallel hybrid electric powertrains in non-road applications, which work in continuous high dynamic operation, this book gives practical insight in to how to maximize the energetic efficiency and drivability of such powertrains. The book addresses an energy management control structure, which considers all constraints of the physical powertrain and uses novel methodologies for the prediction of the future load requirements to optimize the controller output in terms of an entire work cycle of a non-road vehicle. The load prediction includes a methodology for short term loads as well as for an entire load cycle by means of a cycle detection. A maximization of the energetic efficiency can so be achieved, which is simultaneously a reduction in fuel consumption and exhaust emissions. Readers will gain a deep insight into the necessary topics to be considered in designing an energy and battery management system for non-road vehicles and that only a combinatio...

  18. Generating efficiency: The power of price caps in the public and private Spanish electricity sectors

    International Nuclear Information System (INIS)

    Arocena, P.; Price, C.W.

    1999-01-01

    Economic regulation of firms with market power has placed increasing emphasis on incentive-based regulation such as price caps. The move to such regulation often coincides with a change of ownership, making it difficult to separate the incentive effects. We focus on the effect of regulation alone by analysing the imposition of price cap type regulation on both publicly and privately owned Spanish electricity generators in 1988, several years before three was any change of ownership. Our initial results indicate that the publicly owned generators are generally more efficient than the private ones, but that the effect of price caps is to increase the efficiency of private sector plants faster than those in the public sector. We introduce two novelties into the analysis: we incorporate levels of CO2 and NOx emissions; and we include declared plant availability as an output. The outcome is dependent on the choice of inputs and outputs, and we argue that our measures are more appropriate than traditional measures for a system of central despatch for generators facing environmental constraints. (au) 37 refs

  19. Electrical efficiency and renewable energy - Economical alternatives to large-scale power generation

    International Nuclear Information System (INIS)

    Oettli, B.; Hammer, S.; Moret, F.; Iten, R.; Nordmann, T.

    2010-05-01

    This final report for WWF Switzerland, Greenpeace Switzerland, the Swiss Energy Foundation SES, Pro Natura and the Swiss Cantons of Basel City and Geneva takes a look at the energy-relevant effects of the propositions made by Swiss electricity utilities for large-scale power generation. These proposals are compared with a strategy that proposes investments in energy-efficiency and the use of renewable sources of energy. The effects of both scenarios on the environment and the risks involved are discussed, as are the investments involved. The associated effects on the Swiss national economy are also discussed. For the efficiency and renewables scenario, two implementation variants are discussed: Inland investments and production are examined as are foreign production options and/or import from foreign countries. The methods used in the study are introduced and discussed. Investment and cost considerations, earnings and effects on employment are also reviewed. The report is completed with an extensive appendix which, amongst other things, includes potential reviews, cost estimates and a discussion on 'smart grids'

  20. Efficiency and environmental impacts of electricity restructuring on coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Chan, H. Ron [Maryland Univ., College Park, MD (United States). Dept. of Economics; Fell, Harrison [Colorado School of Mines, Golden, CO (United States). Division of Economics and Business; Lange, Ian [Stirling Univ. (United Kingdom). Division of Economics; Li, Shanjun [Cornell Univ., Ithaca, NY (United States). Dyson School of Applied Economics and Management

    2013-03-15

    We investigate the impacts of electricity market restructuring on fuel efficiency, utilization and, new to this area, cost of coal purchases among coal-fired power plants using a panel data set from 1991 to 2005. Our study focuses exclusively on coal-fired power plants and uses panel data covering several years after implementation of restructuring. The estimation compares how investor-owned (IOs) plants in states with restructuring changed their behavior relative to IOs in states without. Our analysis finds that restructuring led to: (1) a two percent improvement in fuel efficiency for IOs, (2) a ten percent decrease in unit cost of heat input, and (3) a lower capacity factor even after adjusting for cross-plant generation re-allocation due to cost reductions. Based on these estimates, back-of-the-envelope calculations find that restructuring has led to about 6.5 million dollars in annual cost savings or nearly 12 percent of operating expenses and up to a 7.6 percent emissions reduction per plant.

  1. The environmental and efficiency effects of restructuring on the electric power sector in the United States. An empirical analysis

    International Nuclear Information System (INIS)

    Sharabaroff, Alexander; Boyd, Roy; Chimeli, Ariaster

    2009-01-01

    Recent measures to restructure the electric power sector in different US states have raised the interest of policy makers, commentators, and the general public as to the actual impact of restructuring on both the economy and the environment. This paper focuses on two aspects of restructuring, namely its potential impact on the efficiency of electricity generation and air pollution. Our empirical results suggest that restructuring contributes to improved efficiency of electricity generation and better air quality through reduced electricity-induced sulfur dioxide (SO 2 ) and carbon dioxide (CO 2 ) emissions, although no effect was found for emissions of nitrous oxides (NO x ). These results, in turn could have important implications for policy in this area. (author)

  2. Radical production efficiency and electrical characteristics of a coplanar barrier discharge built by multilayer ceramic technology

    International Nuclear Information System (INIS)

    Jõgi, Indrek; Erme, Kalev; Levoll, Erik; Stamate, Eugen

    2017-01-01

    The present study investigated the electrical characteristics and radical production efficiency of a coplanar barrier discharge (CBD) device manufactured by Kyocera by multilayer ceramic technology. The device consisted of a number of linear electrodes with electrode and gap widths of 0.75 mm, immersed into a ceramic dielectric barrier. A closed flow-through system necessary for the measurements was prepared by placing a quartz plate at a height of 3 mm from the ceramic barrier. The production of nitrogen radicals was determined from the removal of a trace amount of NO in pure N 2 gas, while the production of oxygen radicals was determined by ozone production in pure O 2 or synthetic air. The production efficiency of N and O radicals and NO oxidation in synthetic air was comparable with the efficiency of a volume barrier discharge device. The power density per unit of surface area of the CBD device was more than two times larger than that of a similar volume barrier discharge setup, which makes the CBD device a compact alternative for gas treatment. The production of ozone and different nitrogen oxides was also evaluated for the open system of the CBD which is usable for surface treatment. The ozone concentration of this system was nearly independent from the input power, while the concentration of nitrogen oxides increased with input power. The open system of the CBD was additionally tested for the treatment of a silicon surface. An increase of applied power decreased the time required to reduce the water contact angle below 10 degrees but also started to have an impact on the surface roughness. (paper)

  3. Behavior of high efficiency electric motors; Comportamiento de motores electricos de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Bonett, Austin H. [IEEE, (United States)

    2001-09-01

    The energy efficiency is one of the main parameters in the design of the industrial motors of general purpose; nevertheless, it is avoided that it is at the cost of the reliability or to the global performance of the motor. Exist user groups of this equipment that consider that, in the search of a greater efficiency, the useful life period is diminished and the characteristics of operation of the motor are affected. During the past last years, the author has studied the aspects of quality and reliability, as well as the operative advantages of the high efficiency motors and written down the increasing interest for these aspects. Also he has detected that a great number of users has realized that, additionally to the obvious energy saving, the efficient motor offers a greater reliability and a longer useful life in most of the industrial applications. The objective of this article is to present the differences in the quality levels, reliability and operation parameters of high efficiency squirrel cage type electrical motors with those of the motors of standard manufacture. [Spanish] La eficiencia energetica es uno de los principales parametros en el diseno de los motores industriales de proposito general; sin embargo, se evita que sea a costa de la confiabilidad o del desempeno global del motor. Existen grupos de usuarios de estos equipos que consideran que, en la busqueda de una mayor eficiencia, se disminuye el periodo de vida util y se afectan las caracteristicas de operacion del motor. Durante los ultimos anos, el autor ha estudiado los aspectos de calidad y confiabilidad, asi como las ventajas operativas de los motores de alta eficiencia y anotado el incremento del interes por estos aspectos. Tambien ha detectado que un gran numero de usuarios se ha dado cuenta que, adicionalmente a los obvios ahorros de energia, el motor eficiente ofrece una mayor confiabilidad y una vida util mas larga en la mayoria de las aplicaciones industriales. El objetivo de este

  4. The Science Camp Model based on maker movement and tinkering activity for developing concept of electricity in middle school students to meet standard evaluation of ordinary national educational test (O-NET)

    Science.gov (United States)

    Chamrat, Suthida

    2018-01-01

    The standard evaluation of Thai education relies excessively on the Ordinary National Educational Test, widely known as O-NET. However, a focus on O-Net results can lead to unsatisfactory teaching practices, especially in science subjects. Among the negative consequences, is that schools frequently engage in "cramming" practices in order to elevate their O-NET scores. Higher education, which is committed to generating and applying knowledge by socially engaged scholars, needs to take account of this situation. This research article portrays the collaboration between the faculty of education at Chiang Mai University and an educational service area to develop the model of science camp. The activities designed for the Science Camp Model were based on the Tinkering and Maker Movement. Specifically, the Science Camp Model was designed to enhance the conceptualization of electricity for Middle School Students in order to meet the standard evaluation of the Ordinary National Educational Test. The hands-on activities consisted of 5 modules which were simple electrical circuits, paper circuits, electrical measurement roleplay motor art robots and Force from Motor. The data were collected by 11 items of Electricity Socratic-based Test adapted from cumulative published O-NET tests focused on the concept of electricity concept. The qualitative data were also collected virtually via Flinga.com. The results indicated that students after participating in 5modules of science camp based on the Maker Movement and tinkering activity developed average percentage of test scores from 33.64 to 65.45. Gain score analysis using dependent t-test compared pretest and posttest mean scores. The p value was found to be statistically significant (less than 0.001). The posttest had a considerably higher mean score compared with the pretest. Qualitative data also indicated that students could explain the main concepts of electrical circuits, and the transformation of electrical energy to

  5. Replacement or additional purchase: The impact of energy-efficient appliances on household electricity saving under public pressures

    International Nuclear Information System (INIS)

    Mizobuchi, Kenichi; Takeuchi, Kenji

    2016-01-01

    This study examined the influence of additional and replacement purchases of energy-efficient air-conditioners on power savings. We used a questionnaire survey and measured electricity use data from 339 Japanese households, collected from two city areas with different level of government-requested electricity-saving rates, namely, Osaka (10%) and Matsuyama (5%). The main findings of our study are as follows: (1) Households that purchased energy-efficient air-conditioners saved more electricity than those that did not. (2) “Additional-purchase households” showed significant energy savings, whereas “replacement households” did not. The rebound effect may negate the energy-saving effects of a new air-conditioner. (3) Altruistic attitude is associated with more active participation in power saving. (4) Households in Osaka saved more electricity than those in Matsuyama, probably because the government call to save electricity was more forceful. - Highlights: •Energy efficient air conditioner purchases affect household power savings. •Additional air conditioner purchase led to significant energy savings. •Replacement units did not produce more savings than non-purchase. • “Electricity conservation directives” amount had a significant power-saving effect. •Altruistic households were more likely to cooperate with power-saving requests.

  6. The study of water droplets electrical charging effect on spray tower scrubber efficiency for feldspar particles removal

    Directory of Open Access Journals (Sweden)

    R Golmohammadi

    2012-01-01

    Full Text Available Background and aims: One of the modern ways introduced nowadays for increasing the collection efficiency of particulate, is the use of electric charge in wet scrubbers. These systems can be used in places in which scrubbers are suitable for contaminant collection. In fact, this system only increases the collection efficiency, and it is not a new technology for contaminant collection.   Methods: First, according to ACGIH recommendation for pilot study a ventilation system was designed and installed. Later, water was charged by using an DC electric exchanger (1275 Volt, DC& product 3×1014 electron on system. Air velocity in the duct was determined by Pitot tube, pressure drop and speed equations, and sampling prop diameter was calculated considering isokenetic conditions. Sampling was performed at two flow rates of 20.3 and 11.4 liter per minute and in overall 72 samples were collected. Sample analysis was performed using gravimetric method and data analysis was performed using SPSS software.      Results: The collection efficiency of inhalable particles in the flow rate of 20.3 liter per minute in a non-electric intervention, and electric intervention with positive and negative charge was 66, 77.67 and 73 percent and in the flow rate of 11.4 liters per minute 60, 69.43 and 68.32 percent respectively. For non-inhalable particles the efficiency in the flow rate 20.3 liter per minute in a non-electric intervention and electric intervention with positive and negative charge was 94.67, 98.33 and 97.67 percent, and in the flow charge of 11/4 liter per minute the flow charge was 91.33, 95, and 97.33 percent respectively.  Conclusion: The results obtained from the experiments, showed that in a certain flow rate, electric intervention increases the efficiency of inhalable particle collection. By the way, this electric intervention has no significant effect on non-inhalable particle collection. Also, the effect of electric intervention with

  7. Net Locality

    DEFF Research Database (Denmark)

    de Souza e Silva, Adriana Araujo; Gordon, Eric

    Provides an introduction to the new theory of Net Locality and the profound effect on individuals and societies when everything is located or locatable. Describes net locality as an emerging form of location awareness central to all aspects of digital media, from mobile phones, to Google Maps......, to location-based social networks and games, such as Foursquare and facebook. Warns of the threats these technologies, such as data surveillance, present to our sense of privacy, while also outlining the opportunities for pro-social developments. Provides a theory of the web in the context of the history...... of emerging technologies, from GeoCities to GPS, Wi-Fi, Wiki Me, and Google Android....

  8. Comparison the programs of energy efficiency for industrial electric motors; Comparacao de programas de eficiencia energetica para motores eletricos industriais

    Energy Technology Data Exchange (ETDEWEB)

    Mariotoni, Carlos Alberto; Naturesa, Jim Silva; Santos Junior, Joubert Rodrigues dos; Demanboro, Antonio Carlos [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo. Nucleo Interdisciplinar de Planejamento Energetico (NIPE)]. E-mail: cam@fec.unicamp.br; jimnaturesa@yahoo.com; joubert@fec.unicamp.br; anto1810@fec.unicamp.br

    2006-07-01

    This paper aims to present a comparison among the existing programs of energy efficiency for industrial electric motors in Brazil, in the United States of America and in the European Community. The analysis is restricted to the action of each program, considering that the mentioned countries present distinct economical, political and social characteristics. Therefore, it is intended to discuss the main barriers existing in the Brazilian industrial context which cause difficulties to develop a program of electric motors efficiency and to indicate some ways to overcome those barriers. (author)

  9. Understanding Net Zero Energy Buildings

    DEFF Research Database (Denmark)

    Salom, Jaume; Widén, Joakim; Candanedo, José

    2011-01-01

    Although several alternative definitions exist, a Net-Zero Energy Building (Net ZEB) can be succinctly described as a grid-connected building that generates as much energy as it uses over a year. The “net-zero” balance is attained by applying energy conservation and efficiency measures...... and by incorporating renewable energy systems. While based on annual balances, a complete description of a Net ZEB requires examining the system at smaller time-scales. This assessment should address: (a) the relationship between power generation and building loads and (b) the resulting interaction with the power grid...

  10. Increasing electric vehicle policy efficiency and effectiveness by reducing mainstream market bias

    International Nuclear Information System (INIS)

    Green, Erin H.; Skerlos, Steven J.; Winebrake, James J.

    2014-01-01

    Plug-in electric vehicles (PEVs) provide an opportunity for reducing energy use and emissions in the transportation sector. Currently, a number of federal policies are in place to incentivize deployment of PEVs to mainstream consumers with demographics and vehicle attribute preferences most common to today's new vehicle purchasers. This article argues that policies intending to give PEVs a foothold in the market should not focus on mainstream consumers and should instead focus on niche markets—specifically carsharing and postal fleets—and early adopters including green consumers. Two arguments can be made in support of eliminating the mainstream market bias of current policies toward a policy of cultivating niche markets. The first is efficiency: so far PEV policies featuring a mainstream market bias have proven to be inefficient and costly. The second is effectiveness: it is becoming increasingly evident that PEV policies would be more effective in achieving potential societal benefits if they focused on early adopters and niche markets using such approaches as strategic niche management, accessible loans and financing, and appropriately targeted incentives. PEV policies focused on early adopters and niche markets would create complementary system effects that will lead to increased PEV market penetration and realization of intended societal benefits. - Highlights: • We argue that U.S. electric vehicle policies are inefficient and ineffective. • We introduce “mainstream consumer bias” as an explanation for policy deficiencies. • We propose an alternative policy agenda to address some of these policy problems. • Proposed policy options include strategic niche management, targeted R and D and incentives, and loans

  11. Public Health Benefits of End-Use Electrical Energy Efficiency in California: An Exploratory Study

    Energy Technology Data Exchange (ETDEWEB)

    McKone, Thomas E.; Lobscheid, A.B.

    2006-06-01

    This study assesses for California how increasing end-use electrical energy efficiency from installing residential insulation impacts exposures and disease burden from power-plant pollutant emissions. Installation of fiberglass attic insulation in the nearly 3 million electricity-heated homes throughout California is used as a case study. The pollutants nitrous oxides (NO{sub x}), sulfur dioxide (SO{sub 2}), fine particulate matter (PM2.5), benzo(a)pyrene, benzene, and naphthalene are selected for the assessment. Exposure is characterized separately for rural and urban environments using the CalTOX model, which is a key input to the US Environmental Protection Agency (EPA) Tool for the Reduction and Assessment of Chemicals and other environmental Impacts (TRACI). The output of CalTOX provides for urban and rural populations emissions-to-intake factors, which are expressed as an individual intake fraction (iFi). The typical iFi from power plant emissions are on the order of 10{sup -13} (g intake per g emitted) in urban and rural regions. The cumulative (rural and urban) product of emissions, population, and iFi is combined with toxic effects factors to determine human damage factors (HDFs). HDF are expressed as disability adjusted life years (DALYs) per kilogram pollutant emitted. The HDF approach is applied to the insulation case study. Upgrading existing residential insulation to US Department of Energy (DOE) recommended levels eliminates over the assmned 50-year lifetime of the insulation an estimated 1000 DALYs from power-plant emissions per million tonne (Mt) of insulation installed, mostly from the elimination of PM2.5 emissions. In comparison, the estimated burden from the manufacture of this insulation in DALYs per Mt is roughly four orders of magnitude lower than that avoided.

  12. The efficiency improvement potential for coal, oil and electricity in China's manufacturing sectors

    International Nuclear Information System (INIS)

    Li, Ke; Lin, Boqiang

    2015-01-01

    This paper introduces an improved total-factor ESTR (energy-saving target ratio) index, which combines the sequence technique and the “energy direction” to a DEA (data envelopment analysis) model, in order to measure the possible energy saving potential of a manufacturing sector. Afterward, the energy saving potentials of four different energy carriers, namely coal, gasoline, diesel oil and electricity, for 27 manufacturing sectors during the period of 1998–2011 in China are calculated. The results and its policy implications are as follows: (1) the average ESTRs of coal, gasoline, diesel oil and electricity are 1.714%, 49.939%, 24.465% and 3.487% respectively. Hence, energy saving of manufacturing sectors should put more emphasis on gasoline and diesel oil. (2) The key sectors for gasoline saving is the energy-intensive sectors, while the key sectors for diesel oil saving is the equipment manufacturing sectors. (3) The manufacture of raw chemical materials and chemical products sector not only consumes a large amount of oil, but also has a low efficiency of oil usage. Therefore, it is the key sector for oil saving. (4) Manufacture of tobacco and manufacture of communication equipment, computers and other electronic equipment are the benchmark for the four major energy carriers of energy-saving ratios. - Highlights: • An improved total-factor energy-saving target ratio is proposed. • Energy saving potentials of energy carriers for sectors in 1998–2011 are calculated. • Policy implications for energy savings in sectors and energy carriers are discussed. • Some suggestions for the energy policies of China's economy are discussed

  13. Hierarchical Load Tracking Control of a Grid-connected Solid Oxide Fuel Cell for Maximum Electrical Efficiency Operation

    DEFF Research Database (Denmark)

    Li, Yonghui; Wu, Qiuwei; Zhu, Haiyu

    2015-01-01

    efficiency operation obtained at different active power output levels, a hierarchical load tracking control scheme for the grid-connected SOFC was proposed to realize the maximum electrical efficiency operation with the stack temperature bounded. The hierarchical control scheme consists of a fast active...... power control and a slower stack temperature control. The active power control was developed by using a decentralized control method. The efficiency of the proposed hierarchical control scheme was demonstrated by case studies using the benchmark SOFC dynamic model......Based on the benchmark solid oxide fuel cell (SOFC) dynamic model for power system studies and the analysis of the SOFC operating conditions, the nonlinear programming (NLP) optimization method was used to determine the maximum electrical efficiency of the grid-connected SOFC subject...

  14. Differences in regulation and efficiency on the electricity market. A preliminary study in the Market Design program

    International Nuclear Information System (INIS)

    Bergendahl, Goeran; Lindblom, Ted; Olsson, Sven-Olof; Sandoff, Anders

    2001-05-01

    This paper reports the outcome of a pilot study focusing on corporate governance and mechanism design issues concerning the electricity industry. With respect to the on-going deregulation, enlargement and internationalisation of electricity markets, especial emphasis is put on exploring the importance of the regulatory environment for accomplishing overall market efficiency. Throughout this preliminary study a central assumption has been that the actors on electricity markets are trying to maximise profits under conditions of uncertainty and asymmetric information. This means that transaction costs should be taken into consideration when studying and analysing the efficiency of electricity markets. Accordingly, the theoretical framework of this paper is resting largely on information theories, like 'Transaction Cost Economics', 'Agency Theory', 'Public Choice and Regulation' and 'Information Economics'. The pilot study consists of three parts. The first part is focusing on the development of a relevant theoretical framework. This part is demonstrating important pricing principles and regulatory incentives for accomplishing an efficient electricity market and, thus, a fair competition between electricity actors, i.e. power companies and other traders of electricity. In such a market design we have distinguished three cornerstones: 1. Marginal cost based electricity pricing, both for energy and capacity. 2. Long-range planning of production and transmission expansions. 3. Transparent transmission pricing and open access to all regional and local transmission grids. The following areas are examples of theoretical research issues that are of a particular interest in practice: The production and transmission of electricity is characterised by considerable economies of scale. The financing of new production and transmission capacity is, however, hard to manage with internal funding when electricity prices are based on marginal costs. What methods or (pricing) strategies

  15. Walking the Torque: Proposed Work Plan for Energy-Efficiency Policy Opportunities for Electric Motor-Driven Systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Electric motor-driven system is the largest single energy end use accounting for more than 40% of global electricity consumption. This paper sets out an ambitious but achievable target with the global work plan to improve the energy efficiency of electric motor-driven system by 10% to 15% based on the finding of working paper ''Energy-Efficiency Policy Opportunities for Electric Motor-Driven Systems (Waide et al., 2011)''. If governments commit to the proposed work plan immediately and maintain resourcing levels, this could be achieved by 2030 and it would be equivalent to reducing total global electricity use by around 5%. The proposed work plan of this paper is to align regulatory settings within a globally applicable scheme. The IEA believes this target can only be achieved through global co-operation leading to aligned national policy settings that countries can unlock the economies of scale that will result from using more energy efficient EMDS.

  16. The Need for a Higher Fuel Efficiency of the Electricity Sector - An Analysis of Opportunities and Barriers

    Energy Technology Data Exchange (ETDEWEB)

    Klimstra, J.

    2007-07-01

    The electricity sector is the single largest user of primary energy in the world. The issues of fuel prices, security of supply and greenhouse gas emissions are therefore closely connected with electricity generation. The total energy efficiency of the electricity sector is only 32.5% so that quick improvements are required. However, the uncertainty over fuel prices and technology preferences is such that most investors are hesitant. The life of existing, often low-efficiency, power plants is therefore extended. At the same time, the demand for electricity is rapidly increasing and the gap between capacity and demand decreases. This paper intends to bring more clarity into the economic and environmental boundary conditions of power plants. The goal is to find an attractive way for rapid efficiency improvement with an even better system reliability without increasing the costs. The paper discusses fuel price developments and the costs of generating technologies in connection with the typical demand pattern of electricity. Ultimately, it appears that local generation, preferably coupled with cogeneration, can be an important part of the solution. (auth)

  17. Increase of energy efficiency of testing of traction electric machines of direct and pulsating current

    Directory of Open Access Journals (Sweden)

    A.M. Afanasov

    2015-03-01

    Full Text Available The results of the analysis of the effect of the load current of traction electric machines when tested for heating on the total electricity consumption for the test are presented. It is shown that increase of load current at the heating test permits to significantly reduce the consumption of electrical energy, and reduce the testing time without reducing its quality.

  18. Rapid and Efficient Synthesis of Silver Nanofluid Using Electrical Discharge Machining

    Directory of Open Access Journals (Sweden)

    Kuo-Hsiung Tseng

    2013-01-01

    Full Text Available The electrical discharge machining (EDM system has been proven feasible as a rapid and efficient method for silver nanofluid preparation. This study prepared the silver nano-fluid via EDM and investigated the relationship between its process parameters and product characteristics. The prior study had found that the silver nano-fluid prepared by EDM contained both silver nanoparticles and silver ions. Silver ions had revealed the cause of the high suspension of the silver nanoparticles. To examine the relationship between the stability of silver nanofluid and the process parameters, this study quantified the relationship of process parameters to the material removal rate (MRR of silver electrode and silver ion output rate (IOR in the fluid, in order to achieve the most effective process parameter condition. Furthermore, the stability of silver nano-fluid was analyzed by various devices, including UV-Vis spectroscopy, size-distribution, and Zeta-potential analyzer. The effects of MRR, IOR, particle size, Zeta-potential, and optical properties of silver nanofluid under different process parameters are also discussed.

  19. Max Tech Efficiency Electric HPWH with low-GWP Halogenated Refrigerant

    Energy Technology Data Exchange (ETDEWEB)

    Nawaz, Kashif [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Elatar, Ahmed F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-02-01

    A scoping-level analysis was conducted to determine the maximum performance of an electric heat pump water heater (HPWH) with low GWP refrigerants (hydroflouroolefins (HFO), hydrofluorocarbons (HFC), and blends). A baseline heat pump water heater (GE GeoSpring) deploying R-134a was analyzed first using the DOE/ORNL Heat Pump Design Model (HPDM) modeling tool. The model was calibrated using experimental data to match the water temperature stratification in tank, first hour rating, energy factor and coefficient of performance. A CFD modeling tool was used to further refine the HPDM tank model. After calibration, the model was used to simulate the performance of alternative refrigerants. The parametric analysis concluded that by appropriate selection of equipment size and condenser tube wrap configuration the overall performance of emerging low GWP refrigerants for HPWH application not only exceed the Energy Star Energy Factor criteria i.e. 2.20, but is also comparable to some of the most efficient products in the market.

  20. A comprehensive approach for computation and implementation of efficient electricity transmission network charges

    Energy Technology Data Exchange (ETDEWEB)

    Olmos, Luis; Perez-Arriaga, Ignacio J. [Instituto de Investigacion Tecnologica, Universidad Pontificia Comillas, Alberto Aguilera, 23, 28015 Madrid (Spain)

    2009-12-15

    This paper presents a comprehensive design of electricity transmission charges that are meant to recover regulated network costs. In addition, these charges must be able to meet a set of inter-related objectives. Most importantly, they should encourage potential network users to internalize transmission costs in their location decisions, while interfering as least as possible with the short-term behaviour of the agents in the power system, since this should be left to regulatory instruments in the operation time range. The paper also addresses all those implementation issues that are essential for the sound design of a system of transmission network charges: stability and predictability of the charges; fair and efficient split between generation and demand charges; temporary measures to account for the low loading of most new lines; number and definition of the scenarios to be employed for the calculation and format of the final charges to be adopted: capacity, energy or per customer charges. The application of the proposed method is illustrated with a realistic numerical example that is based on a single scenario of the 2006 winter peak in the Spanish power system. (author)

  1. The Question of Energy-Efficient Design of the Automated Electric Drive of Multi-Engine Belt Conveyors

    Directory of Open Access Journals (Sweden)

    Semykina Irina

    2015-01-01

    Full Text Available The article proposes a method for improving the energy efficiency of multi-motor variable frequency electric drives of trunk belt conveyors, based on the conveyor speed changing and controlling of the magnetic state of the motor. At conclusion, economic and energy effects of the implementation are estimated.

  2. Explaining electricity demand and the role of energy and investment literacy on end-use efficiency of Swiss households

    NARCIS (Netherlands)

    Blasch, J.E.; Filippini, Massimo; Boogen, Nina; Kumar, Nilkanth

    2017-01-01

    This paper estimates the level of transient and persistent efficiency in the use of electricity in Swiss households using the newly developed generalized true random effects model (GTREM). An unbalanced panel dataset of 1994 Swiss households from 2010 to 2014 collected via a household survey is used

  3. Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

    Science.gov (United States)

    Lee, Hansang; Jung, Seungmin; Cho, Yoonsung; Yoon, Donghee; Jang, Gilsoo

    2013-11-01

    This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed.

  4. The impact of ownership unbundling on cost efficiency: Empirical evidence from the New Zealand electricity distribution sector

    International Nuclear Information System (INIS)

    Filippini, Massimo; Wetzel, Heike

    2014-01-01

    Several countries around the world have introduced reforms to the electric power sector. One important element of these reforms is the introduction of an unbundling process, i.e., the separation of the competitive activities of supply and production from the monopole activity of transmission and distribution of electricity. There are several forms of unbundling: functional, legal and ownership. New Zealand, for instance, adopted an ownership unbundling in 1998. As discussed in the literature, ownership unbundling produces benefits and costs. One of the benefits may be an improvement in the level of the productive efficiency of the companies due to the use of the inputs in just one activity and a greater level of transparency for the regulator. This paper analyzes the cost efficiency of 28 electricity distribution companies in New Zealand for the period between 1996 and 2011. Using a stochastic frontier panel data model, a total cost function and a variable cost function are estimated in order to evaluate the impact of ownership unbundling on the level of cost efficiency. The results indicate that ownership separation of electricity generation and retail operations from the distribution network has a positive effect on the cost efficiency of distribution companies in New Zealand. The estimated effect of ownership separation suggests a positive average one-off shift in the level of cost efficiency by 0.242 in the short-run and 0.144 in the long-run. - Highlights: • We analyze the impact of ownership unbundling on the level of cost efficiency. • A variable cost frontier function and a total cost frontier function are estimated. • The results suggest a positive one-off shift in the level of cost efficiency

  5. Analysis of the energy efficiency of the implementation power electric generated modules in the CHS

    Science.gov (United States)

    Sukhikh, A. A.; Milyutin, V. A.; Lvova, A. M.

    2017-11-01

    Application on the Central heat source (CHS) local generation of electricity is primarily aimed at solving problems of own needs of electric energy that not only guarantees the independence of the work of the CHS from external electrical networks, but will prevent the stop of heat supply of consumers and defrosting heating networks in case of accidents in electrical networks caused by natural or anthropogenic factors. Open the prospects of electric power supply stand-alone objects, such commercial or industrial objects on the territory of a particular neighborhood.

  6. Comparison based on energy and exergy analyses of the potential cogeneration efficiencies for fuel cells and other electricity generation devices

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, M A [Ryerson Polytechnical Inst., Toronto, (CA). Dept. of Mechanical Engineering

    1990-01-01

    Comparisons of the potential cogeneration efficiencies are made, based on energy and exergy analyses, for several devices for electricity generation. The investigation considers several types of fuel cell system (Phosphoric Acid, Alkaline, Solid Polymer Electrolyte, Molten Carbonate and Solid Oxide), and several fossil-fuel and nuclear cogeneration systems based on steam power plants. In the analysis, each system is modelled as a device for which fuel and air enter, and electrical- and thermal-energy products and material and thermal-energy wastes exit. The results for all systems considered indicate that exergy analyses should be used when analysing the cogeneration potential of systems for electricity generation, because they weigh the usefulnesses of heat and electricity on equivalent bases. Energy analyses tend to present overly optimistic views of performance. These findings are particularly significant when large fractions of the heat output from a system are utilized for cogeneration. (author).

  7. Electricity

    CERN Document Server

    Basford, Leslie

    2013-01-01

    Electricity Made Simple covers the fundamental principles underlying every aspect of electricity. The book discusses current; resistance including its measurement, Kirchhoff's laws, and resistors; electroheat, electromagnetics and electrochemistry; and the motor and generator effects of electromagnetic forces. The text also describes alternating current, circuits and inductors, alternating current circuits, and a.c. generators and motors. Other methods of generating electromagnetic forces are also considered. The book is useful for electrical engineering students.

  8. Studies on the suitability of HDPE material for gill nets

    OpenAIRE

    Subramania Pillai, N.; Boopendranath, M.R.; Kunjipalu, K.K.

    1989-01-01

    The suitability of HDPE yarn and HDPE twine in place of nylon for gill nets has been studied. As regards total catch nylon gill net is found to be better than HDPE nets. However, statistical analysis of the catch in respect of quality fishes shows that HDPE yarn nets are equally efficient as nylon nets.

  9. Estimation of Mangrove Net Primary Production and Carbon Sequestration service using Light Use Efficiency model in the Sunderban Biosphere region, India

    Science.gov (United States)

    Sannigrahi, Srikanta; Sen, Somnath; Paul, Saikat

    2016-04-01

    Net Primary Production (NPP) of mangrove ecosystem and its capacity to sequester carbon from the atmosphere may be used to quantify the regulatory ecosystem services. Three major group of parameters has been set up as BioClimatic Parameters (BCP): (Photosynthetically Active Radiation (PAR), Absorbed PAR (APAR), Fraction of PAR (FPAR), Photochemical Reflectance Index (PRI), Light Use Efficiency (LUE)), BioPhysical Parameters (BPP) :(Normalize Difference Vegetation Index (NDVI), scaled NDVI, Enhanced Vegetation Index (EVI), scaled EVI, Optimised and Modified Soil Adjusted Vegetation Index (OSAVI, MSAVI), Leaf Area Index (LAI)), and Environmental Limiting Parameters (ELP) (Temperature Stress (TS), Land Surface Water Index (LSWI), Normalize Soil Water Index (NSWI), Water Stress Scalar (WS), Inversed WS (iWS) Land Surface Temperature (LST), scaled LST, Vapor Pressure Deficit (VPD), scaled VPD, and Soil Water Deficit Index (SWDI)). Several LUE models namely Carnegie Ames Stanford Approach (CASA), Eddy Covariance - LUE (EC-LUE), Global Production Efficiency Model (GloPEM), Vegetation Photosynthesis Model (VPM), MOD NPP model, Temperature and Greenness Model (TG), Greenness and Radiation model (GR) and MOD17 was adopted in this study to assess the spatiotemporal nature of carbon fluxes. Above and Below Ground Biomass (AGB & BGB) was calculated using field based estimation of OSAVI and NDVI. Microclimatic zonation has been set up to assess the impact of coastal climate on environmental limiting factors. MODerate Resolution Imaging Spectroradiometer (MODIS) based yearly Gross Primary Production (GPP) and NPP product MOD17 was also tested with LUE based results with standard model validation statistics: Root Mean Square of Error (RMSE), Mean Absolute Error (MEA), Bias, Coefficient of Variation (CV) and Coefficient of Determination (R2). The performance of CASA NPP was tested with the ground based NPP with R2 = 0.89 RMSE = 3.28 P = 0.01. Among the all adopted models, EC

  10. Netherlands export country for electricity? New developments in power plants and the impact on the Clean and Efficient programme

    International Nuclear Information System (INIS)

    Seebregts, A.J.; Daniels, B.W.

    2008-07-01

    This report explores part of the effects of the Dutch Climate Programme 'Clean and Efficient - Opportunities for Tomorrow' on the emissions of air pollutants, as included in the National Emissions Ceilings. The starting point for the analysis is the ex ante evaluation of Clean and Efficient as published in September 2007. Specifically for the Netherlands, the role of the power generation sector is important. For the near future (up to 2015), about 11 to 15 GW of new fossil generation capacity is being planned. In combination with the Clean and Efficient Programme, this will have a large impact on the resulting national emissions of air pollutants. Strong climate policies and high CO2 prices are likely to result in a lower electricity demand than the original reference projection (the Global Economy High Oil Price scenario). In addition, more renewable electricity generation and more cogeneration are expected. These changes are likely to improve the international competitiveness of the Dutch electricity generation. As a result, electricity exports rise and part of the emission reductions materialize outside the Netherlands, rather than within its borders [nl

  11. Putting the efficiency of the Nordic electricity market to the test

    International Nuclear Information System (INIS)

    Tiusanen, P.

    2003-01-01

    The Nordic electricity market came face to face with a new and unexpected situation in the late summer of 2002. Up until then, there had been plenty of cheap hydropower-based electricity available on the common open market. A beautiful, dry summer changed all that. When the autumn too was dryer than normal and the winter came earlier and with a colder bite to it than normal, the stage was set for a major challenge to the hitherto stable Nordic electricity market. The price of electricity on the Nordic exchange took off, followed not long after by rapidly rising consumer prices

  12. Iron and steel industry and non-ferrous metal production - the electrical energy consumption and energy efficiency

    International Nuclear Information System (INIS)

    Blazhev, Blagoja; Sofeski, Slobodan

    2002-01-01

    Companies of iron and steel industry and non-ferrous metal production are the largest individual consumers of electricity and other forms of energy. This paper presents the electricity consumption in the last twenty-year period as well as data for their contribution in creating the gross domestic product (GDP) and engagement of labor force in the country. For some of the companies there is data for energy efficiency (kWh/t i.e. MJ/t) in last five years. (Original)

  13. Measuring efficiency and productivity change in power electric generation management companies by using data envelopment analysis: A case study

    International Nuclear Information System (INIS)

    Fallahi, Alireza; Ebrahimi, Reza; Ghaderi, S.F.

    2011-01-01

    This paper provides an empirical analysis of the determinants of energy efficiency in 32 power electric generation management companies over the period 2005–2009. The study uses non-parametric Data Envelopment Analysis (DEA) to estimate the relative technical efficiency and productivity change of these companies. In order to verify the stability of our DEA model and the importance of each input variable, a stability test is also conducted. The results of the study indicate that average technical efficiency of companies decreased during the study period. Nearly half of the companies (14) are below this average level of 88.7% for five years. Moreover, it is shown that the low increase of productivity changes is more related to low efficiency rather than technology changes. -- Highlights: ► DEA was applied on the 32 power electric generation management companies. ► A stability test is applied to verify the stability of DEA model. ► Average technical efficiency of companies decreased during the study period. ► The low increase of productivity changes is more related to low efficiency changes.

  14. Electric Vehicles - Promoting Fuel Efficiency and Renewable Energy in Danish Transport

    DEFF Research Database (Denmark)

    Jørgensen, Kaj

    1997-01-01

    Analysis of electric vehicles as energy carrier for renewable energy and fossil fuels, including comparisons with other energy carriers (hydrogen, bio-fuels)......Analysis of electric vehicles as energy carrier for renewable energy and fossil fuels, including comparisons with other energy carriers (hydrogen, bio-fuels)...

  15. Design of an efficient, low weight battery electric vehicle based on a VW Lupo 3L

    NARCIS (Netherlands)

    Besselink, I.J.M.; Oorschot, van P.F.; Nijmeijer, H.

    2010-01-01

    A battery electric vehicle is being developed at the Eindhoven University of Technology, which will beused in future research projects regarding electric mobility. Energy storage in batteries is still at least 25 times heavier and has 10 times the volume in comparison to fossil fuel. This leads to

  16. Sensitivity of Solar Fossil Hybrid Electricity Technology Penetration to Price and Efficiency Projections

    Science.gov (United States)

    With many aging coal and nuclear plants nearing retirement age, new electricity production capacity will need to be built over the next several decades. There are many methods of generating electricity, each with different benefits and drawbacks. While solar and wind generation a...

  17. Properties of porous netted materials

    International Nuclear Information System (INIS)

    Daragan, V.D.; Drozdov, B.G.; Kotov, A.Yu.; Mel'nikov, G.N.; Pustogarov, A.V.

    1987-01-01

    Hydraulic and strength characteristics, efficient heat conduction and inner heat exchange coefficient are experimentally studied for porous netted materials on the base of the brass nets as dependent on porosity, cell size and method of net laying. Results of the studies are presented. It is shown that due to anisotropy of the material properties the hydraulic resistance in the direction parallel to the nets plane is 1.3-1.6 times higher than in the perpendicular one. Values of the effective heat conduction in the direction perpendicular to the nets plane at Π>0.45 agree with the data from literature, at Π<0.45 a deviation from the calculated values is marked in the direction of the heat conduction decrease

  18. Current Status and Future Prospect of K-NET and KiK-net

    Science.gov (United States)

    Aoi, S.; Kunugi, T.; Suzuki, W.; Nakamura, H.; Fujiwara, H.

    2014-12-01

    During 18 years since the deployment of K-NET following the Kobe earthquake, our attention has mainly focused on rapidity of the data collection and an unfailing and reliable observation. In this presentation, we review three generations of the instruments employed by K-NET and KiK-net from these two points of view.At beginning of the 2000's, we newly developed the second generation instruments (K-NET02, K-NET02A, KiK-net06) to replace the first generation instruments (K-NET95, SMAC-MDK) employed when the networks were constructed in the 1990's. These instruments have an automatic dial-out function. It takes typically 2-5 s to establish communication and a few seconds to send the pre-trigger data. After that, data is available typically within a 1.5 s delay. Not only waveform data but also strong motion indexes such as real-time intensity, PGA, PGV, PGD, and response spectra are continuously sent once a second.After the 2011 Tohoku earthquake, we have developed the third generation instruments (K-NET11, KiK-net11) and have replaced almost half of the all stations country wide. Main improvement of this instrument is more unfailing and reliable observation. Because we have often experienced very large ground motions (e.g. 45 records exceeding gravity), the maximum measureable range was expanded from 2000 gal to 4000 gal for the second generation instrument, and to 8000 gal for the third. For the third generation instrument, in case of power failure, observation (including transmission of data) works for seven days thanks to the backup battery, while for the second generation instruments it works only for one day. By adding an oblique component to the three-component accelerometers, we could automatically distinguish shaking data from noise such as electric pulses which may cause a false alarm in EEW. Implementation to guarantee the continuity of observation under severe conditions such as during the Tohoku earthquake is very important, as well as a highly efficient

  19. Toward Highly Efficient Nanostructured Solar Cells Using Concurrent Electrical and Optical Design

    KAUST Repository

    Wang, Hsin-Ping; He, Jr-Hau

    2017-01-01

    potential to push the theoretical limits of solar cell efficiency even higher using the intrinsic advantages associated with these materials, including efficient photon management, rapid charge transfer, and short charge collection distances. However

  20. Application of the modified Wheeler cap method for radiation efficiency measurement of balanced electrically small antennas in complex environment

    DEFF Research Database (Denmark)

    Zhang, Jiaying; Pivnenko, Sergey; Breinbjerg, Olav

    2010-01-01

    In this paper, application of a modified Wheeler cap method for the radiation efficiency measurement of balanced electrically small antennas is presented. It is shown that the limitations on the cavity dimension can be overcome and thus measurement in a large cavity is possible. The cavity loss...... is investigated, and a modified radiation efficiency formula that includes the cavity loss is introduced. Moreover, a modification of the technique is proposed that involves the antenna working complex environment inside the Wheeler Cap and thus makes possible measurement of an antenna close to a hand or head...

  1. Thermal efficiency on welding of AA6061-T6 alloy by modified indirect electric arc and current signals digitalisation

    International Nuclear Information System (INIS)

    Ambriz, R. R.; Barrera, G.; Garcia, R.; Lopez, V. H.

    2009-01-01

    The results of the thermal efficiency on welding by modified indirect electric arc technique (MIEA) [1] of the 6061- T6 aluminum alloy are presented. These values are in a range of 90 to 94 %, which depend of the preheating employed. Thermal efficiency was obtained by means of a balance energy which considers the heat input, the amount of melted mass of the welding profiles, and welding parameters during the joining, especially of the arc current data acquisition. Also, some dimensionless parameters were employed in order to determine the approximation grade of the melted pool, the heat affected zone (HAZ), and their corresponding values with the experimental results. (Author) 13 refs

  2. Rate design, yardstick regulation, and franchise competition: An integrated approach to improving the efficiency of 21st century electric distribution

    Energy Technology Data Exchange (ETDEWEB)

    Reiter, H.L.; Cook, C.

    1999-09-01

    Regulators need to take a hard look at stranded cost policies that make it difficult for municipalities to replace incumbent distributors, and also reconsider whether distributors should be allowed to roll expansion costs into systemwide rates. This article focuses on the importance of efficient electric distribution in the post-restructuring era and how regulators can promote that efficiency by (1) protecting and encouraging franchise competition, (2) employing regulatory yardsticks, and (3) designing rate structures that send proper price signals about the relative costs of expanding distribution plant and substituting distributed generation, conservation services, or other alternatives.

  3. MEASURES OF EFFICIENCY AND INVESTMENTS RETURN: AN STUDY OF BRAZILIAN ELECTRICITY DISTRIBUTORS WITH DATA ENVELOPMENT ANALYSIS, MALMQUIST INDEX AND ROI

    Directory of Open Access Journals (Sweden)

    Valter Saurin

    2013-03-01

    Full Text Available This paper aims to determine, in a group of companies from the Brazilian electric sector, if there is a relationship between the return on investment (ROI and the concept of efficiency estimated by the method Data Envelopment Analysis (DEA, as well as evaluating the growth of productivity based on Malmquist Index (Fare et al, 1996. The hypothesis is that firms that had return on investment higher during certain period of time are those employed their resources efficiently in getting their outputs (DEA efficient. The input (1 Products (5 DEA model correspond to the operating cost (I, the network length (km, the number of consumers and the market billed high, medium and low voltage, respectively. The sample consisted of 31 companies of Brazilian electricity distribution and timing of the study was from 2007 to 2009. We calculated the Malmquist index (M0, represented by the change in total factor productivity (TFPC, which is composed by the evolution of technical efficiency (EC and the change in the technological frontier (TC of the companies were also determined ROI for each period. We calculated the correlation between the TFPC, TC, EC, score the DEA and the ROI for the period 2007 to 2009. The results showed a positive correlation, although weak, between efficiency change and the indexes mentioned above, rejecting the initial hypothesis

  4. Influence of direct and alternating current electric fields on efficiency promotion and leaching risk alleviation of chelator assisted phytoremediation.

    Science.gov (United States)

    Luo, Jie; Cai, Limei; Qi, Shihua; Wu, Jian; Sophie Gu, Xiaowen

    2018-03-01

    Direct and alternating current electric fields with various voltages were used to improve the decontamination efficiency of chelator assisted phytoremediation for multi-metal polluted soil. The alleviation effect of electric field on leaching risk caused by chelator application during phytoremediation process was also evaluated. Biomass yield, pollutant uptake and metal leaching retardation under alternating current (AC) and direct current (DC) electric fields were compared. The biomass yield of Eucalyptus globulus under AC fields with various voltages (2, 4 and 10 V) were 3.91, 4.16 and 3.67kg, respectively, significantly higher than the chelator treatment without electric field (2.71kg). Besides growth stimulation, AC fields increased the metal concentrations of plant tissues especially in aerial parts manifested by the raised translocation factor of different metals. Direct current electric fields with low and moderate voltages increased the biomass production of the species to 3.45 and 3.12kg, respectively, while high voltage on the contrary suppressed the growth of the plants (2.66kg). Under DC fields, metal concentrations elevated obviously with increasing voltages and the metal translocation factors were similar under all voltages. Metal extraction per plant achieved the maximum value under moderate voltage due to the greatest biomass production. DC field with high voltage (10V) decreased the volume of leachate from the chelator treatment without electric field from 1224 to 56mL, while the leachate gathered from AC field treatments raised from 512 to 670mL. DC field can retard the downward movement of metals caused by chelator application more effectively relative to AC field due to the constant water flow and electroosmosis direction. Alternating current field had more promotive effect on chelator assisted phytoremediation efficiency than DC field illustrated by more metal accumulation in the species. However, with the consideration of leaching risk, DC

  5. Research on improving energy efficiency and the annual distributing structure in electricity and gas consumption by extending use of GEHP

    International Nuclear Information System (INIS)

    Yang Zhao; Cheng Heng; Wu Xi; Chen Yiguang

    2011-01-01

    The gas engine-driven heat pump (GEHP), which has been considered as a preferable choice in the heating and air-conditioning scheme can make full use of the waste heat from the engine and achieve a higher primary energy ratio (PER) than other forms of heating/cooling systems. In this paper, the relationship between the capacity characteristic of the GEHP and the heating and cooling loads of buildings has been analyzed. Meanwhile the reasons of the imbalance of the urban electricity and natural gas consumptions between summer and winter have been studied. The running characteristic of a water-to-water GEHP has been investigated experimentally and the PER was measured. Based on the analysis and experimental results, it could be concluded that if both the gas-fired boilers and electric air conditioners are replaced by GEHPs in some percentage, we can narrow the gaps between the requirement and provision of electricity and natural gas and balance the seasonal consumption differences of electricity and natural gas between summer and winter simultaneously. In order to improve energy efficiency, environmental quality and energy consumption structure effectively, the governmental incentive policies for promoting use of GEHPs should be formulated in China and some other developing countries. - Highlights: → The GEHP is more energy-efficient than the traditional electric-driven heat pump. → Capacity of GEHP can be easily adjusted to meet the load variation of buildings. → Extending the use of the GEHP can balance the electricity and gas consumptions. → The GEHP is good for improving the energy consumption configuration of countries. → The GEHP could play an important role in the aspect of society and environment.

  6. Benefits of Hybrid-Electric Propulsion to Achieve 4x Increase in Cruise Efficiency for a VTOL Aircraft

    Science.gov (United States)

    Fredericks, William J.; Moore, Mark D.; Busan, Ronald C.

    2013-01-01

    Electric propulsion enables radical new vehicle concepts, particularly for Vertical Takeoff and Landing (VTOL) aircraft because of their significant mismatch between takeoff and cruise power conditions. However, electric propulsion does not merely provide the ability to normalize the power required across the phases of flight, in the way that automobiles also use hybrid electric technologies. The ability to distribute the thrust across the airframe, without mechanical complexity and with a scale-free propulsion system, is a new degree of freedom for aircraft designers. Electric propulsion is scale-free in terms of being able to achieve highly similar levels of motor power to weight and efficiency across a dramatic scaling range. Applying these combined principles of electric propulsion across a VTOL aircraft permits an improvement in aerodynamic efficiency that is approximately four times the state of the art of conventional helicopter configurations. Helicopters typically achieve a lift to drag ratio (L/D) of between 4 and 5, while the VTOL aircraft designed and developed in this research were designed to achieve an L/D of approximately 20. Fundamentally, the ability to eliminate the problem of advancing and retreating rotor blades is shown, without resorting to unacceptable prior solutions such as tail-sitters. This combination of concept and technology also enables a four times increase in range and endurance while maintaining the full VTOL and hover capability provided by a helicopter. Also important is the ability to achieve low disc-loading for low ground impingement velocities, low noise and hover power minimization (thus reducing energy consumption in VTOL phases). This combination of low noise and electric propulsion (i.e. zero emissions) will produce a much more community-friendly class of vehicles. This research provides a review of the concept brainstorming, configuration aerodynamic and mission analysis, as well as subscale prototype construction and

  7. SEA for strategic grid planning in South Africa: Enabling the efficient and effective roll out of strategic electricity transmission infrastructure

    CSIR Research Space (South Africa)

    Fischer, TD

    2016-05-01

    Full Text Available | Resilience and Sustainability 36th Annual Conference of the International Association for Impact Assessment 11 - 14 May 2016 | Nagoya Congress Center | Aichi-Nagoya | Japan | www.iaia.org SEA FOR STRATEGIC GRID PLANNING IN SOUTH AFRICA: Enabling... the efficient and effective roll out of strategic electricity transmission infrastructure Abstract ID: 409 Authors: Marshall Mabin(1) , Paul Lochner and Dee Fischer Council for Scientific and Industrial Research (CSIR), PO Box 320 Stellenbosch 7599 South...

  8. Targeting Net Zero Energy at Marine Corps Base Kaneohe Bay, Hawaii: Assessment and Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Burman, K.; Kandt, A.; Lisell, L.; Booth, S.; Walker, A.; Roberts, J.; Falcey, J.

    2011-11-01

    DOD's U.S. Pacific Command has partnered with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to assess opportunities for increasing energy security through renewable energy and energy efficiency in Hawaii installations. NREL selected Marine Corps Base Hawaii (MCBH), Kaneohe Bay to receive technical support for net zero energy assessment and planning funded through the Hawaii Clean Energy Initiative (HCEI). NREL performed a comprehensive assessment to appraise the potential of MCBH Kaneohe Bay to achieve net zero energy status through energy efficiency, renewable energy, and electric vehicle integration. This report summarizes the results of the assessment and provides energy recommendations.

  9. Release of Corrosive Species above the Grate in a Waste Boiler and the Implication for Improved Electrical Efficiency

    DEFF Research Database (Denmark)

    Bøjer, Martin; Jensen, Peter Arendt; Dam-Johansen, Kim

    2010-01-01

    A relatively low electrical efficiency of 20−25% is obtained in typical west European waste boilers. Ash species released from the grate combustion zone form boiler deposits with high concentrations of Cl, Na, K, Zn, Pb, and S that cause corrosion of superheater tubes at high temperature....... The superheater steam temperature has to be limited to around 425 °C, and thereby, the electrical efficiency remains low compared to wood or coal-fired boilers. If a separate part of the flue gas from the grate has a low content of corrosive species, it may be used to superheat steam to a higher temperature......, and thereby, the electrical efficiency of the plant can be increased. In this study, the local temperature, the gas concentrations of CO, CO2, and O2, and the release of the volatile elements Cl, S, Na, K, Pb, Zn, Cu, and Sn were measured above the grate in a waste boiler to investigate if a selected fraction...

  10. Assessing energy efficiency of electric car bottom furnaces intended for thermal energization of minerals

    Science.gov (United States)

    Nizhegorodov, A. I.

    2017-01-01

    The paper deals with a new concept of electric furnaces for roasting and thermal energization of vermiculite and other minerals with vibrational transportation of a single-layer mass under constant thermal field. The paper presents performance calculation and comparative assessment of energy data for furnaces of different modifications: flame and electric furnaces with three units, furnaces with six units and ones with series-parallel connection of units, and furnaces of new concept.

  11. Are tax exemptions for electric cars an efficient climate policy measure?

    OpenAIRE

    Geir H. Bjertnæs

    2013-01-01

    This study finds that the welfare gain, excluding environmental effects, generated by increasing the Norwegian tax rate on purchase of electric cars from 8 to 37 percent amounts to approximately 5500- 6500 NOK (or 680-820 euro) per ton increase in GHG emissions in the long run. Substantial tax exemptions implies that reallocation from electric cars towards petrol and diesel powered cars generates a tax revenue gain of more than 40 billion NOK, which amounts to almost 10 percent of government ...

  12. Efficient integration of renewable energies in the German electricity market; Effiziente Integration erneuerbarer Energien in den deutschen Elektrizitaetsmarkt

    Energy Technology Data Exchange (ETDEWEB)

    Nabe, C.A.

    2006-07-01

    Liberalisation of the electricity sector aims to carry out coordination tasks within the system by markets and market prices. This study examines how markets need to be designed to carry out coordination tasks caused by integration of renewable energies in an efficient way. This question is applied to the German electricity system and recommendations are derived from identified deficits. The examination uses the structure-conduct-performance approach of industrial organisation economics. Integration of renewable energies does not result in entirely new coordination tasks but complicates those that exist in any electricity supply system. Within the short-term coordination tasks provision and operation of reserve capacity is affected by renewable energies. Long-term coordination means that the relation between fixed and variable costs of generators as well as generator flexibility has to be adjusted to the characteristics of renewable energies. The relevant short-term coordination task with the network is congestion management. In the long run costs of grid expansion and permanent congestion management have to be balanced. For the execution of short-run coordination tasks integrated and centralised market architectures are superior to decentralised architectures. The increase of short-term coordination tasks due to renewable energies caused by inflexibilities of consumers and conventional generators results in more information that has to be considered. By centralising that information in one market, an increase in productive efficiency can be obtained. In Germany the increased coordination tasks are determined by the integration of wind generators into the electricity system. The present German market architecture results in inefficiencies in short-term coordination. This is demonstrated by an analysis of procedural rules and prices of the ancillary service markets. They demonstrate that market performance is low and significant deviations from competitive prices

  13. Estimating the cost of saving electricity through U.S. utility customer-funded energy efficiency programs

    International Nuclear Information System (INIS)

    Hoffman, Ian M.; Goldman, Charles A.; Rybka, Gregory; Leventis, Greg; Schwartz, Lisa; Sanstad, Alan H.; Schiller, Steven

    2017-01-01

    The program administrator and total cost of saved energy allow comparison of the cost of efficiency across utilities, states, and program types, and can identify potential performance improvements. Comparing program administrator cost with the total cost of saved energy can indicate the degree to which programs leverage investment by participants. Based on reported total costs and savings information for U.S. utility efficiency programs from 2009 to 2013, we estimate the savings-weighted average total cost of saved electricity across 20 states at $0.046 per kilowatt-hour (kW h), comparing favorably with energy supply costs and retail rates. Programs targeted on the residential market averaged $0.030 per kW h compared to $0.053 per kW h for non-residential programs. Lighting programs, with an average total cost of $0.018 per kW h, drove lower savings costs in the residential market. We provide estimates for the most common program types and find that program administrators and participants on average are splitting the costs of efficiency in half. More consistent, standardized and complete reporting on efficiency programs is needed. Differing definitions and quantification of costs, savings and savings lifetimes pose challenges for comparing program results. Reducing these uncertainties could increase confidence in efficiency as a resource among planners and policymakers. - Highlights: • The cost of saved energy allows comparisons among energy resource investments. • Findings from the most expansive collection yet of total energy efficiency program costs. • The weighted average total cost of saved electricity was $0.046 for 20 states in 2009–2013. • Averages in the residential and non-residential sectors were $0.030 and $0.053 per kW h, respectively. • Results strongly indicate need for more consistent, reliable and complete reporting on efficiency programs.

  14. Net Shape 3D Printed NdFeB Permanent Magnet

    OpenAIRE

    Jacimovic, J.; Binda, F.; Herrmann, L. G.; Greuter, F.; Genta, J.; Calvo, M.; Tomse, T.; Simon, R. A.

    2016-01-01

    For two decades, NdFeB based magnets have been a critical component in a range of electrical devices engaged in energy production and conversion. The magnet shape and the internal microstructure of the selected NdFeB grade govern their efficiency and size. However, stricter requirements on device efficiency call for better performing magnets preferably with novel functionality not achievable today. Here we use 3D metal printing by Selective Laser Melting to fabricate dense net shape permanent...

  15. The Boom of Electricity Demand in the Residential Sector in the Developing World and the Potential for Energy Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Letschert, Virginie; McNeil, Michael A.

    2008-05-13

    With the emergence of China as the world's largest energy consumer, the awareness of developing country energy consumption has risen. According to common economic scenarios, the rest of the developing world will probably see an economic expansion as well. With this growth will surely come continued rapid growth in energy demand. This paper explores the dynamics of that demand growth for electricity in the residential sector and the realistic potential for coping with it through efficiency. In 2000, only 66% of developing world households had access to electricity. Appliance ownership rates remain low, but with better access to electricity and a higher income one can expect that households will see their electricity consumption rise significantly. This paper forecasts developing country appliance growth using econometric modeling. Products considered explicitly - refrigerators, air conditioners, lighting, washing machines, fans, televisions, stand-by power, water heating and space heating - represent the bulk of household electricity consumption in developing countries. The resulting diffusion model determines the trend and dynamics of demand growth at a level of detail not accessible by models of a more aggregate nature. In addition, the paper presents scenarios for reducing residential consumption through cost-effective and/or best practice efficiency measures defined at the product level. The research takes advantage of an analytical framework developed by LBNL (BUENAS) which integrates end use technology parameters into demand forecasting and stock accounting to produce detailed efficiency scenarios, which allows for a realistic assessment of efficiency opportunities at the national or regional level. The past decades have seen some of the developing world moving towards a standard of living previously reserved for industrialized countries. Rapid economic development, combined with large populations has led to first China and now India to emerging as &apos

  16. End-User Tools Towards AN Efficient Electricity Consumption: the Dynamic Smart Grid

    Science.gov (United States)

    Kamel, Fouad; Kist, Alexander A.

    2010-06-01

    Growing uncontrolled electrical demands have caused increased supply requirements. This causes volatile electrical markets and has detrimental unsustainable environmental impacts. The market is presently characterized by regular daily peak demand conditions associated with high electricity prices. A demand-side response system can limit peak demands to an acceptable level. The proposed scheme is based on energy demand and price information which is available online. An online server is used to communicate the information of electricity suppliers to users, who are able to use the information to manage and control their own demand. A configurable, intelligent switching system is used to control local loads during peak events and mange the loads at other times as necessary. The aim is to shift end user loads towards periods where energy demand and therefore also prices are at the lowest. As a result, this will flatten the load profile and avoiding load peeks which are costly for suppliers. The scheme is an endeavour towards achieving a dynamic smart grid demand-side-response environment using information-based communication and computer-controlled switching. Diffusing the scheme shall lead to improved electrical supply services and controlled energy consumption and prices.

  17. Implementing energy efficiency: Challenges and opportunities for rural electric co-operatives and small municipal utilities

    International Nuclear Information System (INIS)

    Wilson, Elizabeth J.; Plummer, Joseph; Fischlein, Miriam; Smith, Timothy M.

    2008-01-01

    Challenges in implementing demand side management (DSM) programs in rural electric co-operatives and small municipal utilities are not well understood, yet these organizations sell roughly 15% of electricity in the US, many are more coal-intensive than investor-owned utilities (IOUs), and they are politically important-rural electric co-operatives cover about 75% of the US land area and municipal utilities are found in every state except Hawaii. We provide a background on rural co-operatives and municipal utilities in the context of the US electric sector and highlight the challenges and opportunities of implementing DSM programs in these institutions. Where past studies of utility DSM have mostly focused on IOUs or consisted of qualitative case studies of municipal utilities with exemplary DSM performance, this study makes a unique contribution to the DSM literature by systematically analyzing an entire co-operative and municipal utility population in Minnesota through the use of a survey. In doing so, we provide policy recommendations relevant to energy planners and policy makers to support DSM in rural electric co-operatives and municipal utilities

  18. Hierarchical Load Tracking Control of a Grid-Connected Solid Oxide Fuel Cell for Maximum Electrical Efficiency Operation

    Directory of Open Access Journals (Sweden)

    Yonghui Li

    2015-03-01

    Full Text Available Based on the benchmark solid oxide fuel cell (SOFC dynamic model for power system studies and the analysis of the SOFC operating conditions, the nonlinear programming (NLP optimization method was used to determine the maximum electrical efficiency of the grid-connected SOFC subject to the constraints of fuel utilization factor, stack temperature and output active power. The optimal operating conditions of the grid-connected SOFC were obtained by solving the NLP problem considering the power consumed by the air compressor. With the optimal operating conditions of the SOFC for the maximum efficiency operation obtained at different active power output levels, a hierarchical load tracking control scheme for the grid-connected SOFC was proposed to realize the maximum electrical efficiency operation with the stack temperature bounded. The hierarchical control scheme consists of a fast active power control and a slower stack temperature control. The active power control was developed by using a decentralized control method. The efficiency of the proposed hierarchical control scheme was demonstrated by case studies using the benchmark SOFC dynamic model.

  19. Aplicación de gestión de facturas electrónicas basado en la tecnología .NET

    OpenAIRE

    Cañabate Bernete, Francisco Javier

    2008-01-01

    En la present memòria es presenta el treball realitzat en el projecte de desenvolupament de l'aplicació efactura que pretén fer la gestió de les factures de forma electrònica, sense l'ús de paper. En la presente memoria se presenta el trabajo realizado en el proyecto de desarrollo de la aplicación eFactura que pretende realizar la gestión de las facturas de forma electrónica, sin el uso de papel. This report presents the work completed in the development project of the e-invoice applica...

  20. Energy-efficient control of a multi-section supercapacitor power supply of an electric drive

    Directory of Open Access Journals (Sweden)

    Mozzhechkov Vladimir

    2018-01-01

    Full Text Available A method for synthesizing the control laws of a multi-section supercapacitor power supply of an electric drive is developed. The synthesized control law for an electric drive realizes the prescribed motion and minimizes the required capacitance of the power source. It is achieved through optimal disconnection and connection to the power line of the drive at designated times of one of the power supply sections. Reduction of the required capacitance of the power supply is achieved through a fuller discharge of some of its sections in motion conditions requiring a low level of electrical voltage and saving high voltage in other sections for the respective motion conditions. A mathematical formulation of the problem and a method of its solution is proposed. An example of the implementation of the proposed method is considered.

  1. Russian Electricity Reform 2013 Update: Laying an Efficient and Competitive Foundation for Innovation and Modernisation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-06-01

    Russia is in the process of one of the most ambitious electricity reform programs ever undertaken. The reform is crucial for Russia, with the potential to modernize and transform the sector into a key driver of longer-term economic growth and prosperity. In 2005, the IEA published a study documenting the proposed reform and highlighting some potential implementation issues. Achievements to date have been impressive by international standards, however the outcome remains uncertain. Electricity reform is entering another critical phase in Russia. The 2013 Update examines the key remaining challenges affecting the development of competitive wholesale and retail electricity markets in Russia including: market structure, market design, pricing, investment and related regulation. The report draws extensively on the experience of IEA member countries and on views expressed during consultations with key Russian stakeholders.

  2. Si Hybrid Solar Cells with 13% Efficiency via Concurrent Improvement in Optical and Electrical Properties by Employing Graphene Quantum Dots

    KAUST Repository

    Tsai, Meng Lin; Wei, Wan-Rou; Tang, Libin; Chang, Hung Chih; Tai, Shih Hsiang; Yang, Po Kang; Lau, Shu Ping; Chen, Lih Juann; He, Jr-Hau

    2015-01-01

    By employing graphene quantum dots (GQDs) in PEDOT:PSS, we have achieved an efficiency of 13.22% in Si/PEDOT:PSS hybrid solar cells. The efficiency enhancement is based on concurrent improvement in optical and electrical properties by the photon downconversion process and the improved conductivity of PEDOT:PSS via appropriate incorporation of GQDs. After introducing GQDs into PEDOT:PSS, the short circuit current and the fill factor of rear-contact optimized hybrid cells are increased from 32.11 to 36.26 mA/cm and 62.85% to 63.87%, respectively. The organic-inorganic hybrid solar cell obtained herein holds the promise for developing photon-managing, low-cost, and highly efficient photovoltaic devices.

  3. Si Hybrid Solar Cells with 13% Efficiency via Concurrent Improvement in Optical and Electrical Properties by Employing Graphene Quantum Dots

    KAUST Repository

    Tsai, Meng Lin

    2015-12-18

    By employing graphene quantum dots (GQDs) in PEDOT:PSS, we have achieved an efficiency of 13.22% in Si/PEDOT:PSS hybrid solar cells. The efficiency enhancement is based on concurrent improvement in optical and electrical properties by the photon downconversion process and the improved conductivity of PEDOT:PSS via appropriate incorporation of GQDs. After introducing GQDs into PEDOT:PSS, the short circuit current and the fill factor of rear-contact optimized hybrid cells are increased from 32.11 to 36.26 mA/cm and 62.85% to 63.87%, respectively. The organic-inorganic hybrid solar cell obtained herein holds the promise for developing photon-managing, low-cost, and highly efficient photovoltaic devices.

  4. Consumption and efficiency of a passenger car with a hydrogen/oxygen PEFC based hybrid electric drivetrain

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, F.N.; Dietrich, P.; Tsukada, A.; Koetz, R.; Freunberger, S.A. [Paul Scherrer Institut, Electrochemistry Laboratory, CH-5232 Villigen PSI (Switzerland); Paganelli, G.; Laurent, D.; Varenne, P.; Delfino, A.; Magne, P.A.; Walser, D.; Olsommer, D. [Conception et Developpement Michelin, Route Andre-Piller 30, CH-1762 Givisiez (Switzerland)

    2007-08-15

    The main factors for reducing the consumption of a vehicle are reduction of curb weight, air drag and increase in the drivetrain efficiency. Highly efficient drivetrains can be developed based on PEFC technology and curb weight may be limited by an innovative vehicle construction. In this paper, data on consumption and efficiency of a four-place passenger vehicle with a curb weight of 850 kg and an H{sub 2}/O{sub 2} fed PEFC/Supercap hybrid electric powertrain are presented. Hydrogen consumption in the New European Driving Cycle is 0.67 kg H{sub 2}/100 km, which corresponds to a gasoline equivalent consumption of 2.5 l/100 km. When including the energy needed to supply pure oxygen, the calculated consumption increases from 0.67 to 0.69-0.79 kg H{sub 2}/100 km, depending on the method of oxygen production. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  5. High efficiency direct thermal to electric energy conversion from radioisotope decay using selective emitters and spectrally tuned solar cells

    Science.gov (United States)

    Chubb, Donald L.; Flood, Dennis J.; Lowe, Roland A.

    1993-01-01

    Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1200K. Both selective emitter and filter system TPV systems are feasible. However, requirements on the filter system are severe in order to attain high efficiency. A thin-film of a rare-earth oxide is one method for producing an efficient, rugged selective emitter. An efficiency of 0.14 and power density of 9.2 W/KG at 1200K is calculated for a hypothetical thin-film neodymia (Nd2O3) selective emitter TPV system that uses radioisotope decay as the thermal energy source.

  6. High efficiency direct thermal to electric energy conversion from radioisotope decay using selective emitters and spectrally tuned solar cells

    International Nuclear Information System (INIS)

    Chubb, D.L.; Flood, D.J.; Lowe, R.A.

    1993-08-01

    Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1200K. Both selective emitter and filter system TPV systems are feasible. However, requirements on the filter system are severe in order to attain high efficiency. A thin-film of a rare-earth oxide is one method for producing an efficient, rugged selective emitter. An efficiency of 0.14 and power density of 9.2 W/KG at 1200K is calculated for a hypothetical thin-film neodymia (Nd2O3) selective emitter TPV system that uses radioisotope decay as the thermal energy source

  7. An efficient wireless power transfer system with security considerations for electric vehicle applications

    International Nuclear Information System (INIS)

    Zhang, Zhen; Chau, K. T.; Liu, Chunhua; Qiu, Chun; Lin, Fei

    2014-01-01

    This paper presents a secure inductive wireless power transfer (WPT) system for electric vehicle (EV) applications, such as charging the electric devices inside EVs and performing energy exchange between EVs. The key is to employ chaos theory to encrypt the wirelessly transferred energy which can then be decrypted by specific receptors in the multi-objective system. In this paper, the principle of encrypted WPT is first revealed. Then, computer simulation is conducted to validate the feasibility of the proposed system. Moreover, by comparing the WPT systems with and without encryption, the proposed energy encryption scheme does not involve noticeable power consumption

  8. An efficient wireless power transfer system with security considerations for electric vehicle applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhen; Chau, K. T., E-mail: ktchau@eee.hku.hk; Liu, Chunhua; Qiu, Chun; Lin, Fei [Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

    2014-05-07

    This paper presents a secure inductive wireless power transfer (WPT) system for electric vehicle (EV) applications, such as charging the electric devices inside EVs and performing energy exchange between EVs. The key is to employ chaos theory to encrypt the wirelessly transferred energy which can then be decrypted by specific receptors in the multi-objective system. In this paper, the principle of encrypted WPT is first revealed. Then, computer simulation is conducted to validate the feasibility of the proposed system. Moreover, by comparing the WPT systems with and without encryption, the proposed energy encryption scheme does not involve noticeable power consumption.

  9. An efficient wireless power transfer system with security considerations for electric vehicle applications

    Science.gov (United States)

    Zhang, Zhen; Chau, K. T.; Liu, Chunhua; Qiu, Chun; Lin, Fei

    2014-05-01

    This paper presents a secure inductive wireless power transfer (WPT) system for electric vehicle (EV) applications, such as charging the electric devices inside EVs and performing energy exchange between EVs. The key is to employ chaos theory to encrypt the wirelessly transferred energy which can then be decrypted by specific receptors in the multi-objective system. In this paper, the principle of encrypted WPT is first revealed. Then, computer simulation is conducted to validate the feasibility of the proposed system. Moreover, by comparing the WPT systems with and without encryption, the proposed energy encryption scheme does not involve noticeable power consumption.

  10. Alberta electric industry annual statistics for 1998

    International Nuclear Information System (INIS)

    1999-06-01

    Tables containing data on electric energy generation and capacity for Alberta are provided for the following aspects: capacity and generation of power plants for 1998; capacity of power plants by type, unit, and energy resource for 1998; generating units approved for construction for 1998; generating units completed in 1998; transmission additions approved for construction and completed for 1998; net annual generating capacity and generation for 1988-1998; net monthly generation by plant for 1998; net annual generation by energy resource and type for 1988-1998; net monthly generation by energy resource and type for 1998; generation capacity reserve; relative capacity and generation by type of energy resource for 1998; capacity, generation and fuel consumption of isolated plants for 1998; other industrial on-site plant capacity and generation for 1998. Also listed are: energy resource consumption and energy conversion efficiency of thermal power plants for 1998; stack emissions from thermal generating plants for 1998; non-utility electric generators, wind and hydro for 1998; and hydroelectric energy utilization and conversion efficiency for 1998. Tables contain information on electric energy generation and capacity for hydroelectric energy stored in reservoirs in 1998; details of non-coincident net peak generation and load by utility operators for the Alberta electric system for 1998; and Alberta electric system generation and load at peak load hour for 1998. Further tables cover electric energy distribution for interchange and distribution for 1998 and 1981-1998; annual energy distribution to ultimate customers for 1988-1998 and to ultimate customers for 1998; and the number of electric utility customers in 1998. Final tables cover the transmission and distribution systems with data on: circuit km of such lines for 1988-1998; total circuit km of such lines by major electric utility for 1998 and number of rural electric utility customers for 1998

  11. Net metering in British Columbia : white paper

    International Nuclear Information System (INIS)

    Berry, T.

    2003-01-01

    Net metering was described as being the reverse registration of an electricity customer's revenue meter when interconnected with a utility's grid. It is a provincial policy designed to encourage small-distributed renewable power generation such as micro-hydro, solar energy, fuel cells, and larger-scale wind energy. It was noted that interconnection standards for small generation is an important issue that must be addressed. The British Columbia Utilities Commission has asked BC Hydro to prepare a report on the merits of net metering in order to support consultations on a potential net metering tariff application by the utility. This report provides information on net metering with reference to experience in other jurisdictions with net metering, and the possible costs and benefits associated with net metering from both a utility and consumer perspective. Some of the barriers and policy considerations for successful implementation of net metering were also discussed. refs., tabs., figs

  12. High thermal efficiency and low emission performance of a methanol reformed gas fueled engine for hybrid electric vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, K.; Nakajima, Y.; Shudo, T.; Hiruma, M. [Musahi Inst. of Tech., Tokyo (Japan); Komatsu, H.; Takagi, Y. [Nissan Motor Co., Ltd., Yokosuka (Japan)

    2000-07-01

    An internal combustion engine (ICE) operation was carried out experimentally by using the mixture of air and fuel simulating the reformed gas as the fuel. It has been found that the engine can expectedly attain ultra-low emission and high thermal efficiency, namely 35% brake thermal efficiency in the basis of the low heat value of the theoretically reformed gas or 42% in the basis of the low heat value of methanol. By using the result for the estimation of the total thermal efficiency at the end of the motor output shaft of a hybrid electric vehicle, it has been found that the total thermal efficiency of the reformed gas engine system is 34% in case of a 120% energy increment and 33% in case of a 116% energy increment with a little higher NOx emission of 60 ppm while the counterpart of the fuel cell system is 34%. When the emission level for EZEV is required, the total thermal efficiency falls to 32% in case of a 120% energy increment and 31% in case of a 116% energy increment. From the points of the reliability proved by the long history, higher specific power and low cost, the internal combustion engine system with the thermal efficiency almost equal to that of the fuel cell (FC) system is further more practical when methanol is used as the fuel. (orig.)

  13. Energy-efficient electrical machines by new materials. Superconductivity in large electrical machines; Energieeffiziente elektrische Maschinen durch neue Materialien. Supraleitung in grossen elektrischen Maschinen

    Energy Technology Data Exchange (ETDEWEB)

    Frauenhofer, Joachim [Siemens, Nuernberg (Germany); Arndt, Tabea; Grundmann, Joern [Siemens, Erlangen (Germany)

    2013-07-01

    The implementation of superconducting materials in high-power electrical machines results in significant advantages regarding efficiency, size and dynamic behavior when compared to conventional machines. The application of HTS (high-temperature superconductors) in electrical machines allows significantly higher power densities to be achieved for synchronous machines. In order to gain experience with the new technology, Siemens carried out a series of development projects. A 400 kW model motor for the verification of a concept for the new technology was followed by a 4000 kV A generator as highspeed machine - as well as a low-speed 4000 kW propeller motor with high torque. The 4000 kVA generator is still employed to carry out long-term tests and to check components. Superconducting machines have significantly lower weight and envelope dimensions compared to conventional machines, and for this reason alone, they utilize resources better. At the same time, operating losses are slashed to about half and the efficiency increases. Beyond this, they set themselves apart as a result of their special features in operation, such as high overload capability, stiff alternating load behavior and low noise. HTS machines provide significant advantages where the reduction of footprint, weight and losses or the improved dynamic behavior results in significant improvements of the overall system. Propeller motors and generators,for ships, offshore plants, in wind turbine and hydroelectric plants and in large power stations are just some examples. HTS machines can therefore play a significant role when it comes to efficiently using resources and energy as well as reducing the CO{sub 2} emissions.

  14. Microgrids: An emerging paradigm for meeting building electricity and heat requirements efficiently and with appropriate energy quality

    Energy Technology Data Exchange (ETDEWEB)

    Marnay, Chris; Firestone, Ryan [Berkeley Lab MS 90R4000 (United States)

    2007-07-01

    The first major paradigm shift in electricity generation, delivery, and control is emerging in the developed world, notably Europe, North America, and Japan. This shift will move electricity supply away from the highly centralised universal service quality model with which we are familiar today towards a more dispersed system with heterogeneous qualities of service. One element of dispersed control is the clustering of sources and sinks into semi-autonomous {mu}grids (microgrids). Research, development, demonstration, and deployment (RD3) of {mu}grids are advancing rapidly on at least three continents, and significant demonstrations are currently in progress. This paradigm shift will result in more electricity generation close to end-uses, often involving combined heat and power application for building heating and cooling, increased local integration of renewables, and the possible provision of heterogeneous qualities of electrical service to match the requirements of various end-uses. In Europe, microgrid RD3 is entering its third major round under the 7th European Commission Framework Programme; in the U.S., one specific microgrid concept is undergoing rigorous laboratory testing, and in Japan, where the most activity exists, four major publicly sponsored and two privately sponsored demonstrations are in progress. This evolution poses new challenges to the way buildings are designed, built, and operated. Traditional building energy supply systems will become much more complex in at least three ways: 1. one cannot simply assume gas arrives at the gas meter, electricity at its meter, and the two systems are virtually independent of one another; rather, energy conversion, heat recovery and use, and renewable energy harvesting may all be taking place simultaneously within the building energy system; 2. the structure of energy flows in the building must accommodate multiple energy processes in a manner that permits high overall efficiency; and 3. multiple qualities

  15. Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hansang, E-mail: hslee80@kiu.ac.kr [School of Railway and Electrical Engineering, Kyungil University, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-701 (Korea, Republic of); Jung, Seungmin [School of Electrical Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-712 (Korea, Republic of); Cho, Yoonsung [Department of Electric and Energy Engineering, Catholic University of Daegu, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-702 (Korea, Republic of); Yoon, Donghee [Department of New and Renewable Energy, Kyungil University, Hayang-eup, Gyeongsangbuk-do 712-701 (Korea, Republic of); Jang, Gilsoo, E-mail: gjang@korea.ac.kr [School of Electrical Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-712 (Korea, Republic of)

    2013-11-15

    Highlights: •It is important to develop power and energy management system to save operating cost. •An 100 kWh of SFES is effective to decrease peak power and energy consumption. •Operation cost saving can be achieved using superconducting flywheel energy storage. -- Abstract: This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed.

  16. Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

    International Nuclear Information System (INIS)

    Lee, Hansang; Jung, Seungmin; Cho, Yoonsung; Yoon, Donghee; Jang, Gilsoo

    2013-01-01

    Highlights: •It is important to develop power and energy management system to save operating cost. •An 100 kWh of SFES is effective to decrease peak power and energy consumption. •Operation cost saving can be achieved using superconducting flywheel energy storage. -- Abstract: This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed

  17. Improving the cathode of a microbial fuel cell for efficient electricity production

    NARCIS (Netherlands)

    Heijne, ter A.

    2010-01-01

    The worldwide demand for energy is increasing. At the same time, energy rich wastewaters are currently purified by oxygen supply, which costs a lot of energy. The Microbial Fuel Cell is a new technology that offers advantages in both directions: it produces electricity while purifying wastewaters.

  18. Low-Cost Energy-Efficient 3-D Nano-Spikes-Based Electric Cell Lysis Chips

    KAUST Repository

    Riaz, Kashif; Leung, Siu; Fan, Zhiyong; Lee, Yi-Kuen

    2017-01-01

    Electric cell lysis (ECL) is a promising technique to be integrated with portable lab-on-a-chip without lysing agent due to its simplicity and fast processing. ECL is usually limited by the requirements of high power/voltage and costly fabrication

  19. Flexible interaction of plug-in electric vehicle parking lots for efficient wind integration

    International Nuclear Information System (INIS)

    Heydarian-Forushani, E.; Golshan, M.E.H.; Shafie-khah, M.

    2016-01-01

    Highlights: • Interactive incorporation of plug-in electric vehicle parking lots is investigated. • Flexible energy and reserve services are provided by electric vehicle parking lots. • Uncertain characterization of electric vehicle owners’ behavior is taken into account. • Coordinated operation of parking lots can facilitate wind power integration. - Abstract: The increasing share of uncertain wind generation has changed traditional operation scheduling of power systems. The challenges of this additional variability raise the need for an operational flexibility in providing both energy and reserve. One key solution is an effective incorporation of plug-in electric vehicles (PEVs) into the power system operation process. To this end, this paper proposes a two-stage stochastic programming market-clearing model considering the network constraints to achieve the optimal scheduling of conventional units as well as PEV parking lots (PLs) in providing both energy and reserve services. Different from existing works, the paper pays more attention to the uncertain characterization of PLs takes into account the arrival/departure time of PEVs to/from the PL, the initial state of charge (SOC) of PEVs, and their battery capacity through a set of scenarios in addition to wind generation scenarios. The results reveal that although the cost saving as a consequence of incorporating PL to the grid is below 1% of total system cost, however, flexible interactions of PL in the energy and reserve markets can promote the integration of wind power more than 13.5%.

  20. Enhancing Access to Electricity for Clean and Efficient Energy Services in Africa

    DEFF Research Database (Denmark)

    Christensen, John M.; Mackenzie, Gordon A.; Nygaard, Ivan

    This report examines key issues related to electricity access in Africa, through the lens of selected case studies of countries that have successfully managed to increase access significantly in a short period of time, backed up with more general regional analysis. On the basis of this overview a...

  1. Electricity

    International Nuclear Information System (INIS)

    Tombs, F.

    1983-01-01

    The subject is discussed, with particular reference to the electricity industry in the United Kingdom, under the headings; importance and scope of the industry's work; future fuel supplies (estimated indigenous fossil fuels reserves); outlook for UK energy supplies; problems of future generating capacity and fuel mix (energy policy; construction programme; economics and pricing; contribution of nuclear power - thermal and fast reactors; problems of conversion of oil-burning to coal-burning plant). (U.K.)

  2. The second phase of bipolar, nanosecond-range electric pulses determines the electroporation efficiency.

    Science.gov (United States)

    Pakhomov, Andrei G; Grigoryev, Sergey; Semenov, Iurii; Casciola, Maura; Jiang, Chunqi; Xiao, Shu

    2018-03-29

    Bipolar cancellation refers to a phenomenon when applying a second electric pulse reduces ("cancels") cell membrane damage by a preceding electric pulse of the opposite polarity. Bipolar cancellation is a reason why bipolar nanosecond electric pulses (nsEP) cause weaker electroporation than just a single unipolar phase of the same pulse. This study was undertaken to explore the dependence of bipolar cancellation on nsEP parameters, with emphasis on the amplitude ratio of two opposite polarity phases of a bipolar pulse. Individual cells (CHO, U937, or adult mouse ventricular cardiomyocytes (VCM)) were exposed to either uni- or bipolar trapezoidal nsEP, or to nanosecond electric field oscillations (NEFO). The membrane injury was evaluated by time-lapse confocal imaging of the uptake of propidium (Pr) or YO-PRO-1 (YP) dyes and by phosphatidylserine (PS) externalization. Within studied limits, bipolar cancellation showed little or no dependence on the electric field intensity, pulse repetition rate, chosen endpoint, or cell type. However, cancellation could increase for larger pulse numbers and/or for longer pulses. The sole most critical parameter which determines bipolar cancellation was the phase ratio: maximum cancellation was observed with the 2nd phase of about 50% of the first one, whereas a larger 2nd phase could add a damaging effect of its own. "Swapping" the two phases, i.e., delivering the smaller phase before the larger one, reduced or eliminated cancellation. These findings are discussed in the context of hypothetical mechanisms of bipolar cancellation and electroporation by nsEP. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. A well-conditioned integral-equation formulation for efficient transient analysis of electrically small microelectronic devices

    KAUST Repository

    Bagci, Hakan

    2010-05-01

    A hierarchically regularized coupled set of time-domain surface and volume electric field integral-equations (TD-S-EFIE and TD-V-EFIE) for analyzing electromagnetic wave interactions with electrically small and geometrically intricate composite structures comprising perfect electrically conducting surfaces and finite dielectric volumes is presented. A classically formulated coupled set of TD-S- and V-EFIEs is shown to be ill-conditioned at low frequencies owing to the hypersingular nature of the TD-S-EFIE. To eliminate low-frequency breakdown in marching-on-in-time solvers for these coupled equations, a hierarchical regularizer leveraging generalized RaoWiltonGlisson functions is applied to the TD-S-EFIE; no regularization is applied to the TD-V-EFIE as it is protected from low-frequency breakdown by an identity term. The resulting hierarchically regularized hybrid TD-S- and V-EFIE solver is applicable to the analysis of wave interactions with electrically small and densely meshed structures of arbitrary topology. The accuracy, efficiency, and applicability of the proposed solver are demonstrated by analyzing crosstalk in a six-port transmission line, radiation from a miniature radio-frequency identification antenna, and, plane-wave coupling onto a partially-shielded and fully loaded two-layer computer board. © 2006 IEEE.

  4. New, efficient and viable system for ethanol fuel utilization on combined electric/internal combustion engine vehicles

    Science.gov (United States)

    Sato, André G.; Silva, Gabriel C. D.; Paganin, Valdecir A.; Biancolli, Ana L. G.; Ticianelli, Edson A.

    2015-10-01

    Although ethanol can be directly employed as fuel on polymer-electrolyte fuel cells (PEMFC), its low oxidation kinetics in the anode and the crossover to the cathode lead to a substantial reduction of energy conversion efficiency. However, when fuel cell driven vehicles are considered, the system may include an on board steam reformer for converting ethanol into hydrogen, but the hydrogen produced contains carbon monoxide, which limits applications in PEMFCs. Here, we present a system consisting of an ethanol dehydrogenation catalytic reactor for producing hydrogen, which is supplied to a PEMFC to generate electricity for electric motors. A liquid by-product effluent from the reactor can be used as fuel for an integrated internal combustion engine, or catalytically recycled to extract more hydrogen molecules. Power densities comparable to those of a PEMFC operating with pure hydrogen are attained by using the hydrogen rich stream produced by the ethanol dehydrogenation reactor.

  5. Divergence in technical efficiency of electric utilities: Evidence from the SAPP

    International Nuclear Information System (INIS)

    Jaunky, Vishal Chandr

    2013-01-01

    This paper investigates the convergence pattern of technical efficiency of the South Africa Power Pool (SAPP) utilities over the period April 2003–March 2010 by means of parametric and non-parametric techniques. Technical efficiency scores are computed via both stochastic frontier analysis and data envelopment analysis. Mixed results are obtained from the neoclassical convergence approaches. In addition, distribution dynamics methods reveal some evidence of club-formation and this result is supported with the occurrence of γ-divergence. Taken as a whole, technical efficiency is found to diverge among the utilities operating in the power pool. -- Highlights: •The technical efficiency convergence pattern within the South Africa Power Pool is assessed. •Mixed results are obtained from the parametric neoclassical convergence approaches. •Evidence of divergence is revealed by the non-parametric convergence approaches

  6. State Support for Promotion of Electrical Energy Produced in High Efficiency Cogeneration in Romania

    Directory of Open Access Journals (Sweden)

    Mushatescu V.

    2016-12-01

    Full Text Available Romania accumulated a useful experience in supporting high efficient cogeneration through a bonus type scheme. Spreading this experience to other countries that can choose a similar support scheme could lead to important savings and better results in developing this efficient tool. This state aid is operational, targeted to new investments stimulation for cogeneration technologies and replacement or existing plants rehabilitation. Present paper focuses on the results of support scheme after five years of its application: increase of number of producers who benefit of this aid, raising of general efficiency of high efficient cogeneration, important savings of primary energy and CO2 emissions avoided. On the other hand, use of this scheme showed a number of problems (to which this paper proposes adequate solutions on institutional/administrative, investition, technical, economical-financial and social frameworks that influences beneficiaries and/or financiers of state aid.

  7. Electric and hybrid vehicles charge efficiency tests of ESB EV-106 lead acid batteries

    Science.gov (United States)

    Rowlette, J. J.

    1981-01-01

    Charge efficiencies were determined by measurements made under widely differing conditions of temperature, charge procedure, and battery age. The measurements were used to optimize charge procedures and to evaluate the concept of a modified, coulometric state of charge indicator. Charge efficiency determinations were made by measuring gassing rates and oxygen fractions. A novel, positive displacement gas flow meter which proved to be both simple and highly accurate is described and illustrated.

  8. A Pattern Analysis of Daily Electric Vehicle Charging Profiles: Operational Efficiency and Environmental Impacts

    Directory of Open Access Journals (Sweden)

    Ranjit R. Desai

    2018-01-01

    Full Text Available Plug-in Electric Vehicles (PEVs are considered one solution to reducing GHG emissions from private transport. Additionally, PEV adopters often have free access to public charging facilities. Through a pattern analysis, this study identifies five distinct clusters of daily PEV charging profiles observed at the public charging stations. Empirically observed patterns indicate a significant amount of operational inefficiency, where 54% of the total parking duration PEVs do not consume electricity, preventing other users from charging. This study identifies the opportunity cost in terms of GHG emissions savings if gasoline vehicles are replaced with potential PEV adopters. The time spent in parking without charging by current PEV users can be used by these potential PEV users to charge their PEVs and replace the use of gasoline. The results suggest that reducing inefficient station use leads to significant reductions in emissions. Overall, there is significant variability in outcomes depending on the specific cluster membership.

  9. Electric power supply and the influence of changes on renewable sources' utilisation and energy efficiency

    International Nuclear Information System (INIS)

    Kurek, J.

    2000-01-01

    Changes expected to occur at the electricity market min the Republic of Croatia will have a considerable influence on the development of renewable sources and on the interest in the rationalisation of electricity consumption. If this area and its significance within the total, not only energy-related but also social relations, is stimulated by the law, the influence will be a positive one. Post-liberalisation experience of developed European countries presented in this paper implies arising problems, which can be partly avoided by means of anticipated legislative alternations. Special attention is paid to the possibility of introducing additional work places through a new market approachz, renewable sources' utilisation and consumption rationalisation. (author)

  10. Efficient Healing Takes Some Nerve: Electrical Stimulation Enhances Innervation in Cutaneous Human Wounds.

    Science.gov (United States)

    Emmerson, Elaine

    2017-03-01

    Cutaneous nerves extend throughout the dermis and epidermis and control both the functional and reparative capacity of the skin. Denervation of the skin impairs cutaneous healing, presenting evidence that nerves provide cues essential for timely wound repair. Sebastian et al. demonstrate that electrical stimulation promotes reinnervation and neural differentiation in human acute wounds, thus accelerating wound repair. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

  11. The Efficiency of the National Electricity Board in Malaysia – an Intercountry Comparison

    OpenAIRE

    Jamaluddin bin Mohd Yunos; David Hawdon

    1996-01-01

    One of the most pressing questions facing developing countries and the international agencies that finance their economic programmes is the appropriate way in which to operate and manage their power industries. Until recently, power industries have been regarded as public sector utilities to be operated as monopolies in order to achieve a variety of policy goals. Much international policy has been directed towards reducing the state’s role in the electricity sector, and promoting efforts to p...

  12. Design of Electricity Markets for Efficient Balancing of Wind Power Generation

    OpenAIRE

    Scharff, Richard

    2015-01-01

    Deploying wind power to a larger extent is one solution to reduce negative environmental impacts of electric power supply. However, various challenges are connected with increasing wind power penetration levels. From the perspective of transmission system operators, this includes balancing of varying as well as - to some extent - uncertain generation levels. From the perspective of power generating companies, changes in the generation mix will affect the market's merit order and, hence, their...

  13. Analysis of electrical audit and energy efficiency in building Hotel BC, North Jakarta

    Science.gov (United States)

    Wahyudi Biantoro, Agung

    2018-03-01

    The Hotel BC is using power source from PLN with capacity of 4300 kVA which is divided into 3 units of 2000 kVA transformer. Transformers are used to supply the load of Mall tenants, and Utility loads, such as Chiller, pumps and others. Problems found in the field are complaints from the hotel regarding the safety of electrical installations and wasteful, inefficient electrical costs. The purpose of this study is to check the electrical installation in the building and determine the Energy Use Intensity (EUI) and the cost of payment according to usage based on historical data of the building then compare it with the EUI standard of Ministry of Energy and Mineral Resources of Indonesia. The method used is survey measurement method and quantitative descriptive analysis by comparing in general condition of energy consumption of this building with standard issued by Ministry of Energy and Mineral Resources of Indonesia. The EUI is average 645.58 kWh/m2/year, or 53.79 kWh/m2/month, this is inefficient category, because its EUI value is > 24 kWh / m2 / month. For Electrical audit on imaging thermal test at Panel Out Going of chiller pump, 200 ampere, the highest temperature is 97.3° C, at 200 ampere phase S termination, and this is included in the major category. The numbers of hot spots on the Capacitor bank panels are 10 major points and Chiller panel has 10 major. There are many major points and they are quite dangerous because they can cause fire hazard on the panel. The AC average temperature and humidity distribution did not meet the standard of SNI (Indonesia National Standard).

  14. The effectiveness of energy efficiency improvement in a developing country: Rebound effect of residential electricity use in South Korea

    International Nuclear Information System (INIS)

    Jin, Sang-Hyeon

    2007-01-01

    The government of South Korea considers an energy efficiency improvement policy an effective economic measure for climate change like many other governments. But it is unaware of any 'rebound effect', the unexpected result of energy efficiency improvement. So the rebound effect of residential electricity use in South Korea was estimated using two different scales in this paper. At the macro level, the rebound effect was estimated indirectly by using price elasticity, and at the micro level, the rebound effect of individual home appliances was estimated directly by using a non-linear relationship between energy efficiency and energy use. At the macro level, the long- and short-term results of rebound effect were estimated at 30% and 38%, respectively. Also at the micro level, the rebound effect of air conditioners was 57-70%; while refrigerators showed only a composite of rebound and income effects. Finally, there was no backfire effect, and efficiency improvement brought energy reduction. In conclusion, these suggest that rebound effect is an important factor that the government of South Korea must consider when planning its energy efficiency improvement policy. (author)

  15. Wheel Slip Control for Improving Traction-Ability and Energy Efficiency of a Personal Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Kanghyun Nam

    2015-07-01

    Full Text Available In this paper, a robust wheel slip control system based on a sliding mode controller is proposed for improving traction-ability and reducing energy consumption during sudden acceleration for a personal electric vehicle. Sliding mode control techniques have been employed widely in the development of a robust wheel slip controller of conventional internal combustion engine vehicles due to their application effectiveness in nonlinear systems and robustness against model uncertainties and disturbances. A practical slip control system which takes advantage of the features of electric motors is proposed and an algorithm for vehicle velocity estimation is also introduced. The vehicle velocity estimator was designed based on rotational wheel dynamics, measurable motor torque, and wheel velocity as well as rule-based logic. The simulations and experiments were carried out using both CarSim software and an experimental electric vehicle equipped with in-wheel-motors. Through field tests, traction performance and effectiveness in terms of energy saving were all verified. Comparative experiments with variations of control variables proved the effectiveness and practicality of the proposed control design.

  16. Electrical guidance efficiency of downstream-migrating juvenile Sea Lamprey decreases with increasing water velocity

    Science.gov (United States)

    Miehls, Scott M.; Johnson, Nicholas; Haro, Alexander

    2017-01-01

    We tested the efficacy of a vertically oriented field of pulsed direct current (VEPDC) created by an array of vertical electrodes for guiding downstream-moving juvenile Sea Lampreys Petromyzon marinus to a bypass channel in an artificial flume at water velocities of 10–50 cm/s. Sea Lampreys were more likely to be captured in the bypass channel than in other sections of the flume regardless of electric field status (on or off) or water velocity. Additionally, Sea Lampreys were more likely to be captured in the bypass channel when the VEPDC was active; however, an interaction between the effects of VEPDC and water velocity was observed, as the likelihood of capture decreased with increases in water velocity. The distribution of Sea Lampreys shifted from right to left across the width of the flume toward the bypass channel when the VEPDC was active at water velocities less than 25 cm/s. The VEPDC appeared to have no effect on Sea Lamprey distribution in the flume at water velocities greater than 25 cm/s. We also conducted separate tests to determine the threshold at which Sea Lampreys would become paralyzed. Individuals were paralyzed at a mean power density of 37.0 µW/cm3. Future research should investigate the ability of juvenile Sea Lampreys to detect electric fields and their specific behavioral responses to electric field characteristics so as to optimize the use of this technology as a nonphysical guidance tool across variable water velocities.

  17. Improved electrical efficiency and bottom ash quality on waste combustion plants. Appendix A11 to A14

    Energy Technology Data Exchange (ETDEWEB)

    Hedegaard Madsen, O.; Boejer, M.; Jensen, Peter A.; Dam-Johansen, K.; Lundtorp, K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Mogensen, Erhardt (Babcock and Wilcox Voelund A/S, Glostrup (Denmark))

    2010-07-01

    Investigations making it possible to evaluate and further develop concepts to improve electrical efficiency in a waste combustion plant were performed. Furthermore, one objective of the study was to investigate the possibilities of improving waste bottom ash leaching properties by use of a rotary kiln treatment. The project work included construction of a bench-scale rotary kiln, performing ash rotary kiln treatment experiments, conducting gas suction probe measurements on a waste incineration plant and making some concept evaluations. The influence of the rotary kiln thermal treatment on the leaching of Ca, Al, Si, Mg, Ba, Sr, Cl, Cu, Pb, Zn, Cr, Mo, sulfate, DOC and carbonate was determined. As a result of these tests, the rotary kiln thermal treatment of bottom ashes can be recommended for reducing the leaching of Cu, Pb, Cl, Zn and DOC; however, an increased leaching of Cr and Mo should be expected. The combustion conditions above the grate of a waste incineration plant were investigated and the release and concentration of volatile ash species in the flue gas such as Cl, Na, K, Ca, Pb, Zn and S were measured. The conducted measurements show that flue gas from grate sections 3 and 4 can produce a sufficiently hot flue gas that contains only low concentrations of corrosive species, and therefore can be used to increase superheater temperatures. Implementation of the so-called flue gas split concept together with other steam circle modifications on a waste combustion plant, and using a reasonable increase in final steam temperature from 400 to 500 deg. C, have the potential to increase electrical efficiency from 24 to 30% (with respect to lower fuel heating value) in a waste combustion plant. The appendices deal with electrical efficiency by dividing the combustion products; release of potentially corrosive constituents from the grate; CFD modeling of grate with and without vertical divider. (Author)

  18. The Effects of Coal Switching and Improvements in Electricity Production Efficiency and Consumption on CO2 Mitigation Goals in China

    Directory of Open Access Journals (Sweden)

    Li Li

    2015-07-01

    Full Text Available Although the average CO2 emission for a person in China is only about 1/4 that of a person in the US, the government of China still made a commitment to ensure that CO2 emissions will reach their peak in 2030 because of the ever-increasing pressure of global warming. In this work, we examined the effects of coal switching, efficiency improvements in thermal power generation and the electricity consumption of economic activities on realizing this goal. An improved STIRPAT model was developed to create the scenarios. In order to make the estimated elasticities more consistent with different variables selected to construct the formulation, a double-layer STIRPAT model was constructed, and by integrating the two equations obtained by regressing the series in each layer, we finally got the equation to describe the long-run relationship among CO2 emissions (Ic, the share of coal in overall energy consumption (FMC, coal intensity of thermal power generation (CIp and electricity intensity of GDP (EIelec. The long term elasticities represented by the equation show that the growth of CO2 emissions in China is quite sensitive to FMC, CIp and EIelec. After that, five scenarios were developed in order to examine the effects of China’s possible different CO2 emission reduction policies, focusing on improving FMC, CIp and EIelec respectively. Through a rigorous analysis, we found that in order to realize the committed CO2 emissions mitigating goal, China should obviously accelerate the pace in switching from coal to low carbon fuels, coupled with a consistent improvement in electricity efficiency of economic activities and a slightly slower improvement in the coal efficiency of thermal power generation.

  19. A thermally regenerative ammonia-based battery for efficient harvesting of low-grade thermal energy as electrical power

    KAUST Repository

    Zhang, Fang

    2015-01-01

    © 2015 The Royal Society of Chemistry. Thermal energy was shown to be efficiently converted into electrical power in a thermally regenerative ammonia-based battery (TRAB) using copper-based redox couples [Cu(NH3)4 2+/Cu and Cu(ii)/Cu]. Ammonia addition to the anolyte (2 M ammonia in a copper-nitrate electrolyte) of a single TRAB cell produced a maximum power density of 115 ± 1 W m-2 (based on projected area of a single copper mesh electrode), with an energy density of 453 W h m-3 (normalized to the total electrolyte volume, under maximum power production conditions). Adding a second cell doubled both the voltage and maximum power. Increasing the anolyte ammonia concentration to 3 M further improved the maximum power density to 136 ± 3 W m-2. Volatilization of ammonia from the spent anolyte by heating (simulating distillation), and re-addition of this ammonia to the spent catholyte chamber with subsequent operation of this chamber as the anode (to regenerate copper on the other electrode), produced a maximum power density of 60 ± 3 W m-2, with an average discharge energy efficiency of ∼29% (electrical energy captured versus chemical energy in the starting solutions). Power was restored to 126 ± 5 W m-2 through acid addition to the regenerated catholyte to decrease pH and dissolve Cu(OH)2 precipitates, suggesting that an inexpensive acid or a waste acid could be used to improve performance. These results demonstrated that TRABs using ammonia-based electrolytes and inexpensive copper electrodes can provide a practical method for efficient conversion of low-grade thermal energy into electricity.

  20. Net savings

    International Nuclear Information System (INIS)

    Roche, P.

    2001-01-01

    The state of e-commerce in the Canadian upstream oil and natural gas sector is examined in an effort to discover the extent to which the .com economy has penetrated the marketplace. The overall assessment is that although the situation varies from producer to producer and process to process, a bustling digital marketplace in the Canadian oil business has yet to emerge. Nevertheless, there are several examples of companies using e-business tools to minimize technology staffing and to eliminate wasteful practices. Initiatives cited include streamlining of supply chains to cut handling costs, using application service providers to trim information technology budgets, and adopting electronic joint interest billing to save on printing, postage and re-entering data. Most notable efforts have been made by companies such as BXL Energy Limited and Genesis Exploration Limited, both of which are boosting efficiency on the inside by contracting out data storage and software applications. For example, BXL has replaced its microfilm log library occupying six cabinets, and totalling about 9,000 lbs., by a fibre optic line. All applications can now be run from a laptop which weighs three to four pounds. In a similar vein, Genesis Exploration started using application service providers (ASPs) to avoid the cost and hassle of buying and maintaining major software applications in-house. By accessing the ASPs, Genesis staff can run software without buying or installing it on their own computers. In yet another example of cutting information technology costs, Pengrowth Corporation has its network administration done remotely over the Internet by Northwest Digital Systems (NWD). As far as the industry at large is concerned, the answer appears to be in a digital marketplace specifically tailored to the upstream sector's unique profile. As a start, a study is underway by Deloitte Consulting to explore producer interest in joining or founding an upstream digital marketplace. The study was

  1. Net savings

    Energy Technology Data Exchange (ETDEWEB)

    Roche, P.

    2001-02-01

    The state of e-commerce in the Canadian upstream oil and natural gas sector is examined in an effort to discover the extent to which the .com economy has penetrated the marketplace. The overall assessment is that although the situation varies from producer to producer and process to process, a bustling digital marketplace in the Canadian oil business has yet to emerge. Nevertheless, there are several examples of companies using e-business tools to minimize technology staffing and to eliminate wasteful practices. Initiatives cited include streamlining of supply chains to cut handling costs, using application service providers to trim information technology budgets, and adopting electronic joint interest billing to save on printing, postage and re-entering data. Most notable efforts have been made by companies such as BXL Energy Limited and Genesis Exploration Limited, both of which are boosting efficiency on the inside by contracting out data storage and software applications. For example, BXL has replaced its microfilm log library occupying six cabinets, and totalling about 9,000 lbs., by a fibre optic line. All applications can now be run from a laptop which weighs three to four pounds. In a similar vein, Genesis Exploration started using application service providers (ASPs) to avoid the cost and hassle of buying and maintaining major software applications in-house. By accessing the ASPs, Genesis staff can run software without buying or installing it on their own computers. In yet another example of cutting information technology costs, Pengrowth Corporation has its network administration done remotely over the Internet by Northwest Digital Systems (NWD). As far as the industry at large is concerned, the answer appears to be in a digital marketplace specifically tailored to the upstream sector's unique profile. As a start, a study is underway by Deloitte Consulting to explore producer interest in joining or founding an upstream digital marketplace. The study

  2. Efficiency of the hybrid solar-wind systems for electricity supply to the stand-alone sites

    International Nuclear Information System (INIS)

    Abdullaev, D.A.; Isaev, R.I.

    2000-01-01

    The features of stand-alone sites and principles of their electricity supply is described there is going observation of the works about conditions of production and efficiency of using autonomy wind turbines and photovoltaics. Their unsufficiency is estimated. The advantages of hybrid systems and their realization schemes is described. The advantage of hybrid solar-wind Battery system (HSWBS) on the basis of own researches and the facts of other authors are given. The conception overall discounting cost is developed on HSWBS case. (Author)

  3. Efficiency of Electrical Stunning by Electronarcosis: Current Situation and Perspective of Improvement in a Medium-Size Processing Plant

    Directory of Open Access Journals (Sweden)

    RL Barbosa

    Full Text Available ABSTRACT The objective of this study was to evaluate the efficiency of electrical stunning by electronarcosis in a medium-size poultry processing plant located in southern Brazil. The current measurement of this type of stunning is presented, and then improvements to this method are proposed. Data were collected for 90 days. A quality indicator was proposed: the Stunning Severity Index (SSI, which includes elements of Statistical Process Control (SPC using a p-chart (proportion chart and measures. This index comprises the variables "wing-flapping," "arched head," and "rhythmic breathing." Using the proposed index, 5% of the birds, on average, presented inefficient stunning symptoms.

  4. Highly efficient repetitively pulsed electric-discharge industrial CO2 laser

    International Nuclear Information System (INIS)

    Osipov, V V; Ivanov, M G; Lisenkov, V V; Platonov, V V

    2002-01-01

    The results of investigations aimed at the development of a repetitively pulsed CO 2 laser with an active medium volume of 1000 cm 3 pumped by a combined discharge are generalised. It is shown that, at pump pulse durations of 200-500 μs the optimal characteristics are achieved at active-medium pressures of 60-100 Torr. In this case, the laser efficiency at the initial stage of its operation can reach 22% and; if the energy dissipated in the region of the cathode potential drop is neglected, the efficiency is 28%. After emission of 3x10 5 pulses, the laser efficiency falls to 12%. It has been found that adding CO with a relative concentration [CO]/[CO 2 ] ∼0.75 increases the input and output power by almost 50%. The lasing efficiency is then 10%-12%, and the service life of the laser is by more than 10 6 pulses with a power decrease of no more than 10%. Adding hydrogen up to a concentration [H 2 ]/[CO 2 ] ∼10 leads to an increase in the energy supplied to the gas due to a decrease in the rate of ionisation processes. However, the optimal ratio is [H 2 ]/[CO 2 ] ∼ 1, at which the output power increases by 15%. In a long-term operating mode, the laser power is 1 kW at a peak power of 10 kW and an efficiency of 12%. (lasers)

  5. Study on Enhanceing Mechanisim and Policy on Energy Efficiency of Electrical Motor System in China

    Science.gov (United States)

    Liu, Ren; Zhao, Yuejin; Liu, Meng; Chen, Lili; Yang, Ming

    2017-12-01

    Motor is a kind of terminal energy-consumption equipment with the maximum power consumption in China every year; compared with international advanced level, the technical innovation of motor equipment, speed regulating system, drive system and automatic intelligent control technique in China still lag behind relatively; the standard technical service support system of motor system is not complete, the energy conserving transformation mode needs to be innovated, and the market development mechanism of motor industry is not perfect, etc. This paper analyzes the promotion mechanism and policy on energy efficiency of the motor system in China in recent years, studies the demonstration cases of successful promotion of high-efficiency motor, standard labeling, financial finance and tax policy, and puts forward suggestions on promotion of high-efficiency motor in China.

  6. Gobierno electrónico: diagnóstico de eficiencia en municipios del programa MuNet II – Caso Panamá

    OpenAIRE

    Cortés-Sánchez, Julián David; Cardona, Diego Fernando; Wong, Maribel.

    2014-01-01

    Este documento tiene el objetivo de presentar los resultados del diagnóstico de eficiencia en 26 municipios de Panamá durante la implementación del Programa de Gobierno Electrónico de la Organización de los Estados Americanos –oea– denominado Municipios Eficientes y Transparentes –MuNet–. Este diagnóstico se efectuó en los gobiernos municipales para obtener una visión general sobre factores relacionados con el manejo financiero y administrativo, las compras y obras públicas, la prestación de ...

  7. Energy Savings Potential and Opportunities for High-Efficiency Electric Motors in Residential and Commercial Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Goetzler, William [Navigant Consulting, Inc., Burlington, MA (United States); Sutherland, Timothy [Navigant Consulting, Inc., Burlington, MA (United States); Reis, Callie [Navigant Consulting, Inc., Burlington, MA (United States)

    2013-12-04

    This report describes the current state of motor technology and estimates opportunities for energy savings through application of more advanced technologies in a variety of residential and commercial end uses. The objectives of this report were to characterize the state and type of motor technologies used in residential and commercial appliances and equipment and to identify opportunities to reduce the energy consumption of electric motor-driven systems in the residential and commercial sectors through the use of advanced motor technologies. After analyzing the technical savings potential offered by motor upgrades and variable speed technologies, recommended actions are presented.

  8. Economic feasibility of maximising daylighting of a standard office building with efficient electric lighting

    DEFF Research Database (Denmark)

    Fontoynont, Marc; Ramananarivo, Karine; Soreze, Thierry Silvio Claude

    2016-01-01

    This paper investigates the cost of developing various daylighting strategies for a standard office building in relation to their ability to reduce electric lighting consumption. The reference building design for this study corresponds to a typical configuration that minimises the construction...... costs and is typical of the French market. We have compared scenarios that entail moving service spaces to the periphery, increasing ceiling height and adding light wells of various shapes. These special features increased the proportion of the indoor area with sufficient daylight by up to 40...

  9. Efficiency of a gyroscopic device for conversion of mechanical wave energy to electrical energy

    DEFF Research Database (Denmark)

    Carlsen, Martin; Darula, Radoslav; Gravesen, Jens

    2011-01-01

    We consider a recently proposed gyroscopic device for conversion of mechanical ocean wave energy to electrical energy. Two models of the device derived from standard engineering mechanics from the literature are analysed, and a model is derived from analytical mechanics considerations. From...... these models, estimates of the power production, eciency, forces and moments are made. We nd that it is possible to extract a signicant amount of energy from an ocean wave using the described device. Further studies are required for a full treatment of the device....

  10. The Development of an Energy Efficient Electric Mitad for Baking Injeras in Ethiopia

    NARCIS (Netherlands)

    Jones, Robin; Diehl, J.C.; Simons, Leon; Verwaal, M.

    2017-01-01

    Preparation of Injera, the cultural staple bread food
    item in Ethiopia, is known for its intensive energy consuming
    cooking. Baking this food item in the traditional three stone stoves,
    with an efficiency of 5-15%, consumes huge amounts of firewood
    and causes consequent problems like

  11. ELECTRICITY SAVINGS BY IMPLEMENTING ENERGY EFFICIENCY STANDARDS AND LABELS FOR CLOTHES WASHERS IN MALAYSIA

    Directory of Open Access Journals (Sweden)

    ABU SALEH AHMED

    2011-02-01

    Full Text Available Clothes washers being one of the energy consuming household appliances in Malaysia have become a target for energy efficiency improvements. In the present study, a series of experiment investigations have been conducted on six clothes washers of varying capacities. The objectives are to develop the standards and labels. The test has been performed according to IEC (International Electrotechnical Commision clothes washers test specification. Using the experimental data, a baseline standard has been developed by statistical method. From the baseline standards, 10% standards have been developed. The baseline unit energy consumption was calculated to be 32 Wh/kg/cycle (average unit energy consumption of the six models and on the basis of baseline unit, standard unit energy consumption had been proposed to be 29 Wh/kg/cycle. It has been estimated with the introduction of minimum energy efficiency standards for clothes washer 38077037.46 kWh of energy could be saved per year. To develop a comprehensive energy guide labels, three labels had been design, which were star labeling, speedometer labeling and letter bin labeling. A survey was conducted with three different types of labels among the consumers and with the surveys respond, energy guide label of household clothes washers has been proposed for Malaysia. This is result from used of energy-efficient appliances product and is well positioned to promote more widespread efficient improvement.

  12. Opto-electrical approaches for high efficiency and ultra-thin c-Si solar cells

    NARCIS (Netherlands)

    Ingenito, A.; Isabella, O.; Zeman, M.

    2014-01-01

    The need for cost reduction requires using less raw material and cost-effective processes without sacrificing the conversion efficiency. For keeping high the generated photo-current, an advanced light trapping scheme for ultra-thin silicon wafers is here proposed, exhibiting absorptances up to 99%

  13. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1987-01-01

    The author describes a Petri net model, called coloured Petri nets (CP-nets), by means of which it is possible to describe large systems without having to cope with unnecessary details. The author introduces CP-nets and provide a first impression of their modeling power and the suitability...

  14. Learning Visual Basic NET

    CERN Document Server

    Liberty, Jesse

    2009-01-01

    Learning Visual Basic .NET is a complete introduction to VB.NET and object-oriented programming. By using hundreds of examples, this book demonstrates how to develop various kinds of applications--including those that work with databases--and web services. Learning Visual Basic .NET will help you build a solid foundation in .NET.

  15. Enhancing efficient functioning of the nordic electricity market. Summary and conclusions

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-02-01

    In September 2004, Nordic Council of Ministers (NCM) in their meeting in Akureyri, Iceland, assessed the state of the Nordic electricity market. The Ministers acknowledged that the market has proved it is well functioning in many respects, however, further development of the Nordic electricity market is needed, i.e. towards a regional market without borders. The Nordic Transmission System Operators (TSOs) were asked to study how a further co-ordination of the system responsibility, a joint organizing and financing of the grid investments and a handling of peak load situations can be established in the Nordic countries. In this report, the main focus is on market-related tasks within system responsibility that are market-related and may have an effect on the functioning of the market. The report covers the following issues: definition of the system responsibility and role of TSOs, harmonization of operational rules and practices in order to improve functioning of the market, TSOs' collaboration in disturbances and shortage situations and joint Nordic transmission investments. Furthermore, the report summarizes the concrete actions taken by the TSOs in strengthening of the market mechanisms in peak load situations. (BA)

  16. Enhancing efficient functioning of the nordic electricity market. Summary and conclusions

    International Nuclear Information System (INIS)

    2005-02-01

    In September 2004, Nordic Council of Ministers (NCM) in their meeting in Akureyri, Iceland, assessed the state of the Nordic electricity market. The Ministers acknowledged that the market has proved it is well functioning in many respects, however, further development of the Nordic electricity market is needed, i.e. towards a regional market without borders. The Nordic Transmission System Operators (TSOs) were asked to study how a further co-ordination of the system responsibility, a joint organizing and financing of the grid investments and a handling of peak load situations can be established in the Nordic countries. In this report, the main focus is on market-related tasks within system responsibility that are market-related and may have an effect on the functioning of the market. The report covers the following issues: definition of the system responsibility and role of TSOs, harmonization of operational rules and practices in order to improve functioning of the market, TSOs' collaboration in disturbances and shortage situations and joint Nordic transmission investments. Furthermore, the report summarizes the concrete actions taken by the TSOs in strengthening of the market mechanisms in peak load situations. (BA)

  17. Efficient integration of plug-in electric vehicles via reconfigurable microgrids

    International Nuclear Information System (INIS)

    Kavousi-Fard, Abdollah; Khodaei, Amin

    2016-01-01

    This paper investigates the viability of the reconfigurable microgrids (RMGs) in facilitating the integration of plug-in electric vehicles (PEVs). The reconfiguration ability of microgrids, which is enabled by the use of remotely controlled switches (RCSs), will support the high penetration of PEVs and renewable distributed generators (DGs) while reducing the total operation cost and potentially enhance microgrid reliability. The objective of the proposed optimal scheduling problem is to minimize the total cost of power supply by distributed energy resources (DERs) and upstream network energy exchange, battery degradation cost in PEVs, cost of switching during the reconfiguration, and expected customer interruption costs as a reliability index. To address the high level of the uncertainties in the problem, a scenario-based stochastic framework is devised to capture the uncertainties associated with the charging and discharging values of PEVs, number of PEVs in each fleet, time of the daily trips for PEVs, hourly load consumption, hourly output power of renewable DGs, and hourly market price. The satisfying performance and merits of the proposed model are examined on a test microgrid. - Highlights: • Introduction of reconfigurable microgrids for providing flexible structure to manage electric loads. • Assessing the effects of the reconfiguration on the integration of PEVs. • Introduction of a stochastic framework for reducing operation and reliability costs in microgrids. • Introduction of a smart charge/discharge scheme for PEVs based on V2G during the reconfiguration.

  18. Pulsed Electric Field inactivation of microbial cells: the use of ceramic layers to increase the efficiency of treatment

    International Nuclear Information System (INIS)

    Pizzichemi, M.

    2009-01-01

    The impact of Pulsed Electric Fields (PEF) on bacteria and plant or animal cells has been investigated since the early 1960s. High electric fields pulses (20-70 kV/cm, 1-10 μs) are reported to cause rupture of the cellular lipid membrane, through the mechanism of irreversible electroporation. Quantitative description of cell inactivation kinetics is based on the analysis of stability of lipid bilayers under electric fields and the thermal fluctuations associated with the production of pores. PEF has been successfully applied to inactivation of both Gram-positive and Gram-negative bacteria in many sorts of liquids, such as milk, fruit juices and liquid eggs. In all these media, the level of inactivation could reach the 5 Logs for an approximate range of pulses of 100-200, and an energy consumption of ∼ 10-100 kJ/kg. The advantages of PEF are the superior maintenance of functional and nutritional levels (if compared to traditional thermal treatment), continuous treatment and short processing times, while the current high costs of this technique make it more suitable for treatment of expensive media. We present a solution to the problem of volumes in PEF treatment through the use of high permittivity ceramics, while retaining the same inactivation efficiency and improving the duration of the electrodes.

  19. Investigation of efficiency of electric drive control system of excavator traction mechanism based on feedback on load

    Science.gov (United States)

    Kuznetsov, N. K.; Iov, I. A.; Iov, A. A.

    2018-05-01

    The article presents the results of a study of the efficiency of the electric drive control system of the traction mechanism of a dragline based on the use of feedback on load in the traction cable. The investigations were carried out using a refined electromechanical model of the traction mechanism, which took into account not only the elastic elements of the gearbox, the backlashes in it and the changes in the kinematic parameters of the mechanism during operation, but also the mechanical characteristics of the electric drive and the features of its control system. By mathematical modeling of the transient processes of the electromechanical system, it is shown that the introduction of feedback on the load in the elastic element allows one to reduce the dynamic loads in the traction mechanism and to limit the elastic oscillations of the actuating mechanism in comparison with the standard control system. Fixed as a general decrease in the dynamic load of the nodes of traction mechanism in the modes of loading and latching of the bucket, and a decrease the operating time of the mechanism at maximum load. At the same time, undesirable phenomena in the operation of the electric drive were also associated with the increase in the recovery time of the steady-state value of the speed of the actuating mechanism under certain operating conditions, which can lead to a decrease in the reliability of the mechanical part and the productivity of the traction mechanism.

  20. Electrical Stress Influences the Efficiency of CH3 NH3 PbI3 Perovskite Light Emitting Devices.

    Science.gov (United States)

    Zhao, Lianfeng; Gao, Jia; Lin, YunHui L; Yeh, Yao-Wen; Lee, Kyung Min; Yao, Nan; Loo, Yueh-Lin; Rand, Barry P

    2017-06-01

    Organic-inorganic hybrid perovskite materials are emerging as semiconductors with potential application in optoelectronic devices. In particular, perovskites are very promising for light-emitting devices (LEDs) due to their high color purity, low nonradiative recombination rates, and tunable bandgap. Here, using pure CH 3 NH 3 PbI 3 perovskite LEDs with an external quantum efficiency (EQE) of 5.9% as a platform, it is shown that electrical stress can influence device performance significantly, increasing the EQE from an initial 5.9% to as high as 7.4%. Consistent with the enhanced device performance, both the steady-state photoluminescence (PL) intensity and the time-resolved PL decay lifetime increase after electrical stress, indicating a reduction in nonradiative recombination in the perovskite film. By investigating the temperature-dependent characteristics of the perovskite LEDs and the cross-sectional elemental depth profile, it is proposed that trap reduction and resulting device-performance enhancement is due to local ionic motion of excess ions, likely excess mobile iodide, in the perovskite film that fills vacancies and reduces interstitial defects. On the other hand, it is found that overstressed LEDs show irreversibly degraded device performance, possibly because ions initially on the perovskite lattice are displaced during extended electrical stress and create defects such as vacancies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Pulsed Electric Field inactivation of microbial cells: the use of ceramic layers to increase the efficiency of treatment

    Science.gov (United States)

    Pizzichemi, M.

    2009-12-01

    The impact of Pulsed Electric Fields (PEF) on bacteria and plant or animal cells has been investigated since the early 1960s. High electric fields pulses (20-70 kV/cm, 1-10 μs) are reported to cause rupture of the cellular lipid membrane, through the mechanism of irreversible electroporation. Quantitative description of cell inactivation kinetics is based on the analysis of stability of lipid bilayers under electric fields and the thermal fluctuations associated with the production of pores. PEF has been successfully applied to inactivation of both Gram-positive and Gram-negative bacteria in many sorts of liquids, such as milk, fruit juices and liquid eggs. In all these media, the level of inactivation could reach the 5 Logs for an approximate range of pulses of 100-200, and an energy consumption of ˜ 10-100 kJ/kg. The advantages of PEF are the superior maintenance of functional and nutritional levels (if compared to traditional thermal treatment), continuous treatment and short processing times, while the current high costs of this technique make it more suitable for treatment of expensive media. We present a solution to the problem of volumes in PEF treatment through the use of high permittivity ceramics, while retaining the same inactivation efficiency and improving the duration of the electrodes.

  2. Pulsed Electric Field inactivation of microbial cells: the use of ceramic layers to increase the efficiency of treatment

    Energy Technology Data Exchange (ETDEWEB)

    Pizzichemi, M. [Physics Department, University of Milano - Bicocca (Italy)

    2009-12-15

    The impact of Pulsed Electric Fields (PEF) on bacteria and plant or animal cells has been investigated since the early 1960s. High electric fields pulses (20-70 kV/cm, 1-10 mus) are reported to cause rupture of the cellular lipid membrane, through the mechanism of irreversible electroporation. Quantitative description of cell inactivation kinetics is based on the analysis of stability of lipid bilayers under electric fields and the thermal fluctuations associated with the production of pores. PEF has been successfully applied to inactivation of both Gram-positive and Gram-negative bacteria in many sorts of liquids, such as milk, fruit juices and liquid eggs. In all these media, the level of inactivation could reach the 5 Logs for an approximate range of pulses of 100-200, and an energy consumption of approx 10-100 kJ/kg. The advantages of PEF are the superior maintenance of functional and nutritional levels (if compared to traditional thermal treatment), continuous treatment and short processing times, while the current high costs of this technique make it more suitable for treatment of expensive media. We present a solution to the problem of volumes in PEF treatment through the use of high permittivity ceramics, while retaining the same inactivation efficiency and improving the duration of the electrodes.

  3. Improving the Optical Trapping Efficiency in the 225Ra Electric Dipole Moment Experiment via Monte Carlo Simulation

    Science.gov (United States)

    Fromm, Steven

    2017-09-01

    In an effort to study and improve the optical trapping efficiency of the 225Ra Electric Dipole Moment experiment, a fully parallelized Monte Carlo simulation of the laser cooling and trapping apparatus was created at Argonne National Laboratory and now maintained and upgraded at Michigan State University. The simulation allows us to study optimizations and upgrades without having to use limited quantities of 225Ra (15 day half-life) in experiment's apparatus. It predicts a trapping efficiency that differs from the observed value in the experiment by approximately a factor of thirty. The effects of varying oven geometry, background gas interactions, laboratory magnetic fields, MOT laser beam configurations and laser frequency noise were studied and ruled out as causes of the discrepancy between measured and predicted values of the overall trapping efficiency. Presently, the simulation is being used to help optimize a planned blue slower laser upgrade in the experiment's apparatus, which will increase the overall trapping efficiency by up to two orders of magnitude. This work is supported by Michigan State University, the Director's Research Scholars Program at the National Superconducting Cyclotron Laboratory, and the U.S. DOE, Office of Science, Office of Nuclear Physics, under Contract DE-AC02-06CH11357.

  4. Development of electrical efficiency measurement techniques for 10 kW-class SOFC system: Part II. Uncertainty estimation

    International Nuclear Information System (INIS)

    Tanaka, Yohei; Momma, Akihiko; Kato, Ken; Negishi, Akira; Takano, Kiyonami; Nozaki, Ken; Kato, Tohru

    2009-01-01

    Uncertainty of electrical efficiency measurement was investigated for a 10 kW-class SOFC system using town gas. Uncertainty of heating value measured by the gas chromatography method on a mole base was estimated as ±0.12% at 95% level of confidence. Micro-gas chromatography with/without CH 4 quantification may be able to reduce uncertainty of measurement. Calibration and uncertainty estimation methods are proposed for flow-rate measurement of town gas with thermal mass-flow meters or controllers. By adequate calibrations for flowmeters, flow rate of town gas or natural gas at 35 standard litters per minute can be measured within relative uncertainty ±1.0% at 95 % level of confidence. Uncertainty of power measurement can be as low as ±0.14% when a precise wattmeter is used and calibrated properly. It is clarified that electrical efficiency for non-pressurized 10 kW-class SOFC systems can be measured within ±1.0% relative uncertainty at 95% level of confidence with the developed techniques when the SOFC systems are operated relatively stably

  5. Cost-efficient demand-pull policies for multi-purpose technologies – The case of stationary electricity storage

    International Nuclear Information System (INIS)

    Battke, Benedikt; Schmidt, Tobias S.

    2015-01-01

    Highlights: • A definition of multi-purpose technologies (MPTs) is proposed. • Opportunities for a cost-efficient demand-pull policy strategy for MPTs are derived. • The multi-purpose character of stationary electricity storage (SES) is shown. • An exemplary profitability assessment of one SES technology supports the argument. - Abstract: Stationary electricity storage technologies (SES) allow to increase the shares of intermittent renewable energy technologies in electricity networks. As SES currently exhibit high costs, policy makers have started introducing demand-pull policies in order to foster their diffusion and drive these technologies further down the learning curve. However, as observed in the case of renewable energy technologies, demand-pull policies for technologies can come at high costs in cases where the profitability gap that needs to be covered by the policy support is large. Yet, SES can create value in multiple distinct applications in the power system – making it a “multi-purpose technology”. We argue that policy makers can make use of the multi-purpose character of SES to limit costs of demand-pull policies. We propose a policy strategy which grants support based on the profitability gap in the different applications, thereby moving down the learning curve efficiently. To support our argumentation, we firstly conduct a comprehensive literature review of SES applications exemplifying the multi-purpose character of these technologies. Second, we assess the profitability of one SES technology (vanadium redox flow battery) in five SES applications, highlighting a strong variation of the profitability gap across these applications

  6. Título da página electrónica: Z Net – A Community of People Commited to Social Change

    Directory of Open Access Journals (Sweden)

    José Manuel Mendes

    2012-10-01

    Full Text Available Esta página electrónica inclui-se no projecto Z Communications – The Spirit of Resistance Lives, uma iniciativa lançada por Michael Albert e Lydia Sargent que propõe uma visão crítica e alternativa ao sistema capitalista mundial. Entre os vários colaboradores desta página contam-se, entre outros, Noam Chomsky, Arundhati Roy e Vandana Shiva, com muitos documentos próprios disponíveis. Entre as várias secções que constituem esta página, são de salientar as seguintes: a revista Z Magazine com a...

  7. INCREASING CONTROL’S EFFICIENCY FOR THE SHIP’S TWO-MASS ELECTRIC DRIVE

    Directory of Open Access Journals (Sweden)

    V.V. Budashko

    2016-09-01

    Full Text Available Purpose. For shipboard lifting and transporting machinery (LTM with AC thyristor electric drives (ED the problem of minimizing sway through the formation of the special law to change the principle of ED control over the lifting process is solved. Methodology. This goal was achieved through the following objectives: analysis of current studies on the reduction of the negative effects of load fluctuations, fixed on the suspension with variable parameters; determining the criteria to optimize the movement of the lifting mechanism and transfer control laws under which the load fluctuations are reduced; develop the methodology and experimental study of the main characteristics of the mobile model ED lifting mechanism with its load suspended from the perspective of both the parameterization of the control system (CS as well as elements of ED. For realization of tasks in research methods of mathematical modeling of dynamic processes on the computer, structural methods of control theory, experimental studies in the laboratory setting have been used. Results. Based on analysis of current research can be concluded that the stability of the ED of LTM to the disturbing points provided coincidence zero electric coordinates and speed deviation diametric plane of the vessel from the vertical position. Criteria for optimizing CS used by the ED LTM mathematical description of its dynamics differential equations to the estimated coefficients derived from the functions of state variables. The experimental dependence of dynamic equations of motion of an object under the influence of disturbing forces in the coordinate plane allowed to parameterize characteristic equation to the form, providing the solution to sustainability since the motor shaft of LTM. The functional circuit of CS eliminates the aperiodic components in the control in compliance with the criteria of sustainability and quality of transients by applying all-range regulator coordinate characteristics

  8. Efficiency Analysis of Magnetic Field Measurement for MR Electrical Impedance Tomography (MREIT)

    DEFF Research Database (Denmark)

    Göksu, Cihan; Hanson, Lars G.; Ehses, Philipp

    MREIT is an emerging method to measure the ohmic tissue conductivities, with several potential biomedical applications. Its sensitivity depends on the magnitude of the applied current, which is limited to 1-2 mA in the human brain [1, 2]. This renders in-vivo applications challenging. Here, we ai...... to analyze and optimize the efficiency of two MREIT pulse sequences for in-vivo brain imaging....

  9. Efficient production of electricity and water in cogeneration systems. [Desalination plant

    Energy Technology Data Exchange (ETDEWEB)

    Tadros, S.K.

    1981-11-01

    This paper discusses two topping cycle steam turbine cogeneration systems. The water desalination plant selected is the multistage flash evaporator cycle which uses brine recirculation and high temperature additives for scale protection and 233F maximum brine temperature. The paper mentions briefly the impact of future fuel prices on design and factors which would further improve thermal efficiency. The fuel chargeable to power is determined. 6 refs.

  10. Organic compound destruction and removal efficiency (DRE) for plasma incinerator off-gases using an electrically heated secondary combustion chamber

    International Nuclear Information System (INIS)

    Whitworth, C.G.; Babko-Malyi, S.; Battleson, D.M.; Olstad, S.J.

    1998-01-01

    The US Department of Energy (DOE) sponsored a series pilot-scale plasma incineration tests of simulated mixed wastes at the MSE Technology Applications, Inc. technology development test facility in Butte, MT. One of the objectives of the test series was to assess the ability of an electrically heated afterburner to destroy organic compounds that may be present in the off-gases resulting from plasma incineration of mixed wastes. The anticipated benefit of an electrically heated afterburner was to decrease total off-gas volume by 50% or more, relative to fossil fuel-fired afterburners. For the present test series, feeds of interest to the DOE Mixed Waste Focus Area (MWFA) were processed in a plasma centrifugal furnace while metering selected organic compounds upstream of the electrically heated afterburner. The plasma furnace was equipped with a transferred-mode torch and was operated under oxidizing conditions. Feeds consisted of various mixtures of soil, plastics, portland cement, silicate fines, diesel fuel, and scrap metals. Benzene, chloroform, and 1,1,1-trichloroethane were selected for injection as simulates of organics likely to be present in DOE mixed wastes, and because of their relative rankings on the US Environmental Protection Agency (EPA) thermal stability index. The organic compounds were injected into the off-gas system at a nominal concentration of 2,000 ppmv. The afterburner outlet gas stream was periodically sampled, and analyzed by gas chromatography/mass spectrometry. For the electrically heated afterburner, at operating temperatures of 1,800--1,980 F (982--1,082 C), organic compound destruction and removal efficiencies (DREs) for benzene, chloroform, and 1,1,1-trichloroethane were found to be > 99.99%

  11. Security of supply in electricity markets: Improving cost efficiency of supplying security and possible welfare gains

    DEFF Research Database (Denmark)

    Klinge Jacobsen, Henrik; Grenaa Jensen, Stine

    2012-01-01

    In liberalised markets the ability to maintain security of electricity supply is questioned because security is characterised as a public good. We discuss if this property can be modified with changing technology. Furthermore, we examine if construction of markets for security can be justified...... by possible welfare gains. From a welfare perspective it is possible that security levels are too high and obtained with too high costs. Adjusting the effort so that marginal cost for securing supply is at similar levels in generation capacity and in network maintenance could increase welfare even without...... the need to construct markets. Secondarily, a consumer defined average level of security might improve welfare. Finally, different willingness to pay among customers and construction of advanced markets might increase welfare further. We argue that several cost and welfare improvements can be achieved...

  12. Normal return and efficient operation of the electric grid monopolies; Normalavkastning og effektiv drift for nettmonopolene

    Energy Technology Data Exchange (ETDEWEB)

    Skjeret, Frode Andre

    2001-07-01

    This report deals with the size of the risk premium for electric grid operation in Norway. The size of the companies' risk premium must reflect the market requirements on return compensation (for normal investment risk), adjusted for the return risk for this type of enterprise. The return risk of the grid companies is discussed using two approaches, one theoretical and one empirical. This implies an empirical analysis of comparable foreign companies and an examination of the Norwegian regulatory regime. It is concluded that the regulatory authority is using too small an estimate for the risk premium when determining the capital income of the Norwegian utilities. The report also discusses the principles for valuation of the capital base.

  13. Efficient and large scale synthesis of graphene from coal and its film electrical properties studies.

    Science.gov (United States)

    Wu, Yingpeng; Ma, Yanfeng; Wang, Yan; Huang, Lu; Li, Na; Zhang, Tengfei; Zhang, Yi; Wan, Xiangjian; Huang, Yi; Chen, Yongsheng

    2013-02-01

    Coal, which is abundant and has an incompact structure, is a good candidate to replace graphite as the raw material for the production of graphene. Here, a new solution phase technique for the preparation of graphene from coal has been developed. The precursor: graphene oxide got from coal was examined by atomic force microscopy, dynamic light scattering and X-ray diffraction, the results showed the GO was a small and single layer sheet. The graphene was examined by X-ray photoelectron spectroscopy, and Raman spectroscopy. Furthermore, graphene films have been prepared using direct solution process and the electrical conductivity and Hall effect have been studied. The results showed the conductivity of the films could reach as high as 2.5 x 10(5) Sm(-1) and exhibited an n-type behavior.

  14. How to verify lightning protection efficiency for electrical systems? Testing procedures and practical applications

    Energy Technology Data Exchange (ETDEWEB)

    Birkl, Josef; Zahlmann, Peter [DEHN and SOEHNE, Neumarkt (Germany)], Emails: Josef.Birkl@technik.dehn.de, Peter.Zahlmann@technik.dehn.de

    2007-07-01

    There are increasing numbers of applications, installing Surge Protective Devices (SPDs), through which partial lightning currents flow, and highly sensitive, electronic devices to be protected closely next to each other due to the design of electric distribution systems and switchgear installations which is getting more and more compact. In these cases, the protective function of the SPDs has to be co-ordinated with the individual immunity of the equipment against energetic, conductive impulse voltages and impulse currents. In order to verify the immunity against partial lightning currents of the complete system laboratory tests on a system level are a suitable approach. The proposed test schemes for complete systems have been successfully performed on various applications. Examples will be presented. (author)

  15. Considerations for the selection of an applicable energy efficiency test procedure for electric motors in Malaysia: Lessons for other developing countries

    International Nuclear Information System (INIS)

    Yanti, P.A.A.; Mahlia, T.M.I.

    2009-01-01

    Electric motors are a major energy-consuming appliance in the industrial sector. According to a survey, electric motors account for more than 70% of the total growth from 1991 to 2004 in electricity consumption in this sector in Malaysia. To reduce electricity consumption, Malaysia should consider resetting the minimum energy efficiency standards for electric motors sometime in the coming year. The first step towards adopting energy efficiency standards is the creation of a procedure for testing and rating equipment. An energy test procedure is the technical foundation for all energy efficiency standards, energy labels and other related programs. The test conditions in the test procedure must represent the conditions of the country. This paper presents the process for the selection of an energy test procedure for electric motors in Malaysia based on the country's conditions and requirements. The adoption of test procedures for electric motors internationally by several countries is also discussed in this paper. Even though the paper only discusses the test procedure for electric motors in Malaysia, the methods can be directly applied in other countries without major modifications.

  16. Targeting Net Zero Energy at Fort Carson: Assessment and Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, K.; Markel, T.; Simpson, M.; Leahey, J.; Rockenbaugh, C.; Lisell, L.; Burman, K.; Singer, M.

    2011-10-01

    The U.S. Army's Fort Carson installation was selected to serve as a prototype for net zero energy assessment and planning. NREL performed the comprehensive assessment to appraise the potential of Fort Carson to achieve net zero energy status through energy efficiency, renewable energy, and electric vehicle integration. This report summarizes the results of the assessment and provides energy recommendations. This study is part of a larger cross-laboratory effort that also includes an assessment of renewable opportunities at seven other DoD Front Range installations, a microgrid design for Fort Carson critical loads and an assessment of regulatory and market-based barriers to a regional secure smart grid.

  17. Design and management of energy-efficient hybrid electrical energy storage systems

    CERN Document Server

    Kim, Younghyun

    2014-01-01

    This book covers system-level design optimization and implementation of hybrid energy storage systems. The author introduces various techniques to improve the performance of hybrid energy storage systems, in the context of design optimization and automation. Various energy storage techniques are discussed, each with its own advantages and drawbacks, offering viable, hybrid approaches to building a high performance, low cost energy storage system. Novel design optimization techniques and energy-efficient operation schemes are introduced. The author also describes the technical details of an act

  18. Market (in)efficiency in valuing electric utilities-The case of Norwegian generating companies

    International Nuclear Information System (INIS)

    Kjaerland, Frode

    2010-01-01

    After deregulation of the energy market in Norway, a number of mergers and acquisitions of hydropower generating companies have taken place. However, valuation of these companies has proved controversial. From an ex-post perspective, there is support for the criticism that generation assets have been sold too cheaply. This article presents a simple valuation model providing evidence of how value has evolved. On the basis of these results, we discuss the valuation from an ex ante perspective and in the light of the market efficiency hypothesis of (Fama, 1970) and (Fama, 1991).

  19. Public Policy and Economic Efficiency in Ontario's Electricity Market: 2002 to 2011

    Science.gov (United States)

    Olmstead, Derek E. H.

    A competitive wholesale electricity market began operation in Ontario in 2002. The institutional features and development process are described, and the outcomes associated with certain features are assessed. First, a six-equation model of the market is specified and estimated. The results are used to undertake analysis of the province's renewable energy program. The impacts of the program on consumers' and producers' surplus, as well as the resulting degree of carbon dioxide (CO2) emission-abatement, are estimated. These results are used to infer the per-unit cost of CO 2 abatement resulting from the program. Under the assumption that the renewable-fuelled energy displaces coal-fuelled energy from the market, the estimated cost is approximately 93/tonne of CO2; under the alternative assumption that natural gas-fuelled generation is displaced, the estimated cost is 207/tonne of CO2. Comparison to costs observed in other markets and jurisdictions reveals the program to cost approximately one order of magnitude greater than elsewhere. It is concluded that Ontario pays substantially more for emission abatement than is necessary or, alternatively, that Ontario achieves substantially less abatement than is feasible for each dollar of economic resources expended. Second, the market model is also used to assess the treatment of electricity exports with respect to the so-called global adjustment charge. The analysis reveals that the current practise of exempting exports from the charge is not socially optimal from a total surplus-maximisation standpoint. That objective would be achieved if global adjustment was allocated to exports at approximately 32% of the rate at which it is applied to Ontario-based consumers, a result consistent with a Ramsey-type inverse elasticity rule. Third, the forward market unbiasedness hypothesis is assessed in the context of the market for financial transmission rights (FTR). Issues related to left-censoring of payouts at $0 and overlapping

  20. Industrial electricity demand and energy efficiency policy: The role of price changes and private R and D in the Swedish pulp and paper industry

    International Nuclear Information System (INIS)

    Henriksson, Eva; Söderholm, Patrik; Wårell, Linda

    2012-01-01

    The objective of this paper is to analyze electricity demand behaviour in the Swedish pulp and paper industry in the context of the increased interest in so-called voluntary energy efficiency programs. In these programs tax exemptions are granted if the participating firms carry out energy efficiency measures following an energy audit. We employ a panel data set of 19 pulp and paper firms, and estimate both the own- and cross-price elasticities of electricity demand as well as the impact of knowledge accumulation following private R and D on electricity use. The empirical results show that electricity use in the Swedish pulp and paper industry is relatively own-price insensitive, and the self-reported electricity savings following the voluntary so-called PFE program support the notion of important information asymmetries at the company level. However, the results display that already in a baseline setting pulp and paper firms tend to invest in private R and D that have electricity saving impacts, and our model simulations suggest that up to about one-third of the industry sector's self-reported electricity savings in PFE could be attributable to pure baseline effects. Future evaluations of voluntary energy efficiency programs must increasingly recognize the already existing incentives to reduce energy use in energy-intensive industries. - Highlights: ► We analyze electricity demand behaviour in the Swedish pulp and paper industry. ► An important context is the voluntary energy efficiency programs PFE. ► The electricity savings following PFE are significant, but price responses are low. ► Still, already in a baseline setting firms tend to invest in electricity-saving R and D. ► These baseline issues are not adequately addressed in PFE.