WorldWideScience

Sample records for energy conversion power

  1. Novel Nuclear Powered Photocatalytic Energy Conversion

    International Nuclear Information System (INIS)

    White, John R.; Kinsmen, Douglas; Regan, Thomas M.; Bobek, Leo M.

    2005-01-01

    The University of Massachusetts Lowell Radiation Laboratory (UMLRL) is involved in a comprehensive project to investigate a unique radiation sensing and energy conversion technology with applications for in-situ monitoring of spent nuclear fuel (SNF) during cask transport and storage. The technology makes use of the gamma photons emitted from the SNF as an inherent power source for driving a GPS-class transceiver that has the ability to verify the position and contents of the SNF cask. The power conversion process, which converts the gamma photon energy into electrical power, is based on a variation of the successful dye-sensitized solar cell (DSSC) design developed by Konarka Technologies, Inc. (KTI). In particular, the focus of the current research is to make direct use of the high-energy gamma photons emitted from SNF, coupled with a scintillator material to convert some of the incident gamma photons into photons having wavelengths within the visible region of the electromagnetic spectrum. The high-energy gammas from the SNF will generate some power directly via Compton scattering and the photoelectric effect, and the generated visible photons output from the scintillator material can also be converted to electrical power in a manner similar to that of a standard solar cell. Upon successful implementation of an energy conversion device based on this new gammavoltaic principle, this inherent power source could then be utilized within SNF storage casks to drive a tamper-proof, low-power, electronic detection/security monitoring system for the spent fuel. The current project has addressed several aspects associated with this new energy conversion concept, including the development of a base conceptual design for an inherent gamma-induced power conversion unit for SNF monitoring, the characterization of the radiation environment that can be expected within a typical SNF storage system, the initial evaluation of Konarka's base solar cell design, the design and

  2. Solar thermal energy conversion to electrical power

    International Nuclear Information System (INIS)

    Trinh, Anh-Khoi; González, Ivan; Fournier, Luc; Pelletier, Rémi; Sandoval V, Juan C.; Lesage, Frédéric J.

    2014-01-01

    The conversion of solar energy to electricity currently relies primarily on the photovoltaic effect in which photon bombardment of photovoltaic cells drives an electromotive force within the material. Alternatively, recent studies have investigated the potential of converting solar radiation to electricity by way of the Seebeck effect in which charge carrier mobility is generated by an asymmetric thermal differential. The present study builds upon these latest advancements in the state-of-the-art of thermoelectric system management by combining solar evacuated tube technology with commercially available Bismuth Telluride semiconductor modules. The target heat source is solar radiation and the target heat sink is thermal convection into the ambient air relying on wind aided forced convection. These sources of energy are reproduced in a laboratory controlled environment in order to maintain a thermal dipole across a thermoelectric module. The apparatus is then tested in a natural environment. The novelty of the present work lies in a net thermoelectric power gain for ambient environment applications and an experimental validation of theoretical electrical characteristics relative to a varying electrical load. - Highlights: • Solar radiation maintains a thermal tension which drives an electromotive force. • Voltage, current and electric power are reported and discussed. • Theoretical optimal thermoelectric conversion predictions are presented. • Theory is validated with experimentally measured data

  3. Power production with direct energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Rochau, G.; Lipinski, R.; Polansky, G.; Seidel, D.; Slutz, S. [Sandia National Labs., Albuquerque, NM (United States); Morrow, C. [Morrow Consulting, Albuquerque, NM (United States); Anghaie, S. [Florida Univ., Gainesville, FL (United States); Beller, D. [Los Alamos National Lab., NM (United States); Brown, L. [General Atomic Co., San Diego, CA (United States); Parish, T. [Texas A and M Univ., College Station, TX (United States). Dept. of Nuclear Engineering

    2001-07-01

    The direct energy conversion (DEC) project has as its main goal the development of a direct energy conversion process suitable for commercial development. We define direct energy conversion as any fission process that returns usable energy without using an intermediate thermal process. During the first phase of study, nine different concepts were investigated and 3 were selected: 1) quasi-spherical magnetically insulated fission electrode cell, 2) fission fragment magnetic collimator, and 3) gaseous core reactor with MHD generator. Selection was based on efficiency and feasibility. The realization of their potential requires an investment in both technically and commercially oriented research. The DEC project has a process in place to take one of these concepts forward and to outline the road map for further development. (A.C.)

  4. Power production with direct energy conversion

    International Nuclear Information System (INIS)

    Rochau, G.; Lipinski, R.; Polansky, G.; Seidel, D.; Slutz, S.; Morrow, C.; Anghaie, S.; Beller, D.; Brown, L.; Parish, T.

    2001-01-01

    The direct energy conversion (DEC) project has as its main goal the development of a direct energy conversion process suitable for commercial development. We define direct energy conversion as any fission process that returns usable energy without using an intermediate thermal process. During the first phase of study, nine different concepts were investigated and 3 were selected: 1) quasi-spherical magnetically insulated fission electrode cell, 2) fission fragment magnetic collimator, and 3) gaseous core reactor with MHD generator. Selection was based on efficiency and feasibility. The realization of their potential requires an investment in both technically and commercially oriented research. The DEC project has a process in place to take one of these concepts forward and to outline the road map for further development. (A.C.)

  5. Efficient electrochemical CO2 conversion powered by renewable energy.

    Science.gov (United States)

    Kauffman, Douglas R; Thakkar, Jay; Siva, Rajan; Matranga, Christopher; Ohodnicki, Paul R; Zeng, Chenjie; Jin, Rongchao

    2015-07-22

    The catalytic conversion of CO2 into industrially relevant chemicals is one strategy for mitigating greenhouse gas emissions. Along these lines, electrochemical CO2 conversion technologies are attractive because they can operate with high reaction rates at ambient conditions. However, electrochemical systems require electricity, and CO2 conversion processes must integrate with carbon-free, renewable-energy sources to be viable on larger scales. We utilize Au25 nanoclusters as renewably powered CO2 conversion electrocatalysts with CO2 → CO reaction rates between 400 and 800 L of CO2 per gram of catalytic metal per hour and product selectivities between 80 and 95%. These performance metrics correspond to conversion rates approaching 0.8-1.6 kg of CO2 per gram of catalytic metal per hour. We also present data showing CO2 conversion rates and product selectivity strongly depend on catalyst loading. Optimized systems demonstrate stable operation and reaction turnover numbers (TONs) approaching 6 × 10(6) molCO2 molcatalyst(-1) during a multiday (36 h total hours) CO2 electrolysis experiment containing multiple start/stop cycles. TONs between 1 × 10(6) and 4 × 10(6) molCO2 molcatalyst(-1) were obtained when our system was powered by consumer-grade renewable-energy sources. Daytime photovoltaic-powered CO2 conversion was demonstrated for 12 h and we mimicked low-light or nighttime operation for 24 h with a solar-rechargeable battery. This proof-of-principle study provides some of the initial performance data necessary for assessing the scalability and technical viability of electrochemical CO2 conversion technologies. Specifically, we show the following: (1) all electrochemical CO2 conversion systems will produce a net increase in CO2 emissions if they do not integrate with renewable-energy sources, (2) catalyst loading vs activity trends can be used to tune process rates and product distributions, and (3) state-of-the-art renewable-energy technologies are sufficient

  6. Modeling power electronics and interfacing energy conversion systems

    CERN Document Server

    Simões, Marcelo Godoy

    2017-01-01

    Discusses the application of mathematical and engineering tools for modeling, simulation and control oriented for energy systems, power electronics and renewable energy. This book builds on the background knowledge of electrical circuits, control of dc/dc converters and inverters, energy conversion and power electronics. The book shows readers how to apply computational methods for multi-domain simulation of energy systems and power electronics engineering problems. Each chapter has a brief introduction on the theoretical background, a description of the problems to be solved, and objectives to be achieved. Block diagrams, electrical circuits, mathematical analysis or computer code are covered. Each chapter concludes with discussions on what should be learned, suggestions for further studies and even some experimental work.

  7. Thermal power plant efficiency enhancement with Ocean Thermal Energy Conversion

    International Nuclear Information System (INIS)

    Soto, Rodrigo; Vergara, Julio

    2014-01-01

    In addition to greenhouse gas emissions, coastal thermal power plants would gain further opposition due to their heat rejection distressing the local ecosystem. Therefore, these plants need to enhance their thermal efficiency while reducing their environmental offense. In this study, a hybrid plant based on the principle of Ocean Thermal Energy Conversion was coupled to a 740 MW coal-fired power plant project located at latitude 28°S where the surface to deepwater temperature difference would not suffice for regular OTEC plants. This paper presents the thermodynamical model to assess the overall efficiency gained by adopting an ammonia Rankine cycle plus a desalinating unit, heated by the power plant condenser discharge and refrigerated by cold deep seawater. The simulation allowed us to optimize a system that would finally enhance the plant power output by 25–37 MW, depending on the season, without added emissions while reducing dramatically the water temperature at discharge and also desalinating up to 5.8 million tons per year. The supplemental equipment was sized and the specific emissions reduction was estimated. We believe that this approach would improve the acceptability of thermal and nuclear power plant projects regardless of the plant location. -- Highlights: • An Ocean Thermal Energy Conversion hybrid plant was designed. • The waste heat of a power plant was delivered as an OTEC heat source. • The effect of size and operating conditions on plant efficiency were studied. • The OTEC implementation in a Chilean thermal power plant was evaluated. • The net efficiency of the thermal power plant was increased by 1.3%

  8. Power conversion and control methods for renewable energy sources

    Science.gov (United States)

    Yu, Dachuan

    2005-07-01

    In recent years, there has been an increase in the use of renewable energy due to the growing concern over the pollution caused by fossil-fuel-based energy. Renewable energy sources, such as photovoltaic (PV) and fuel cell, can be used to enhance the safety, reliability, sustainability, and transmission efficiency of a power system. This dissertation focuses on the power conversion and control for two major renewable-energy sources: PV and fuel cell. Firstly, a current-based, maximum power-point tracking (MPPT) algorithm is proposed for PV energy. An economical converter system using the above scheme for converting the output from PV panels into 60 Hz AC voltage is developed and built. Secondly, a novel circuit model for the Proton Exchange Membrane (PEM) fuel-cell stack that is useful in the design and analysis of fuel-cell-based power systems is proposed. This Pspice-based model uses elements available in the Pspice library with some modifications to represent both the static and dynamic responses of a PEM fuel-cell module. The accuracy of the model is verified by comparing the simulation and experimental results. Thirdly, a DSP-controlled three-phase induction-motor drive using constant voltage over frequency is built and can be used in a fuel-cell automobile. A hydrogen sensor is used in the drive to both sound an alarm and shut down the inverter trigger pulses through the DSP. Finally, a hybrid power system consisting of PV panels and fuel cell is proposed and built. In the proposed system, PV panels can supply most of the power when the sunlight is available, and the excess power required by the load is supplied by a fuel cell. Load sharing between a fuel cell (FC) and the PV panel is investigated by both simulation and experiments.

  9. Photovoltaic and thermal energy conversion for solar powered satellites

    Science.gov (United States)

    Von Tiesenhausen, G. F.

    1976-01-01

    A summary is provided concerning the most important aspects of present investigations related to a use of solar power satellites (SPS) as a future source of terrestrial energy. General SPS characteristics are briefly considered, early work is reviewed, and a description of current investigations is presented. System options presently under study include a photovoltaic array, a thermionic system, and a closed Brayton cycle. Attention is given to system reference options, basic building blocks, questions of system analysis and engineering, photovoltaic conversion, and the utility interface. It is concluded that an SPS may be cost effective compared to terrestrial systems by 1995.

  10. Combining Energy Conversion and Storage: A Solar Powered Supercapacitor

    International Nuclear Information System (INIS)

    Narayanan, Remya; Kumar, P. Naresh; Deepa, Melepurath; Srivastava, Avanish Kumar

    2015-01-01

    Graphical abstract: - Highlights: • A plasmonic TiO_2/CdS/Au fibers photoanode is fabricated for the first time. • The efficiency of the plasmonic cell is greater by 1.35 times than the non-plasmonic one. • A solar powered supercapacitor is developed with plasmonic photoanode and multiwalled carbon nanotubes. • The solar cell current charges the supercapacitor. • A specific capacitance of 150 F g"−"1 is achieved under sunlight without any external bias. - Abstract: A solar powered supercapacitor wherein a plasmonic quantum dot solar cell (QDSC) sources the photocurrent for charging/discharging a conjoined supercapacitor based on multiwalled carbon nanotubes (MWCNTs) is demonstrated. Gold or Au fibers are integrated into a titanium dioxide/cadmium sulfide (TiO_2/CdS) electrode to yield a TiO_2/CdS/Au photoanode. The plasmonic effect of Au fibers is reflected in the higher incident photon to current conversion efficiency (IPCE = 55%) and an improved overall power conversion efficiency (3.45%) produced by the TiO_2/CdS/Au photoanode relative to the non-plasmonic TiO_2/CdS photoanode. A Janus type bi-functional electrode composed of MWCNTs on either face separated by glass is prepared and it is coupled with the TiO_2/CdS/Au electrode and another MWCNT electrode to yield the tandem solar powered supercapacitor. By channelling the photocurrent produced by the QDSC part, under 0.1 sun illumination, the capacitance of the symmetric supercapacitor, without the application of any external bias is 150 F g"−"1 which compares well with reported values of electrically powered MWCNT supercapacitors. Our innovative design for a photo-supercapacitor offers a new paradigm for combining low cost photovoltaics with energy storage to yield a technologically useful device that needs nothing else other than solar energy to run.

  11. Space electric power design study. [laser energy conversion

    Science.gov (United States)

    Martini, W. R.

    1976-01-01

    The conversion of laser energy to electrical energy is discussed. Heat engines in which the laser heats the gas inside the engine through a window as well as heat engines in which the gas is heated by a thermal energy storage reservoir which has been heated by laser radiation are both evaluated, as well as the necessary energy storage, transmission and conversion components needed for a full system. Preliminary system concepts are presented and a recommended development program is outlined. It appears possible that a free displacer Stirling engine operating directly a linear electric generator can convert 65% of the incident laser energy into electricity.

  12. Energy Conversion Advanced Heat Transport Loop and Power Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Oh, C. H.

    2006-08-01

    The Department of Energy and the Idaho National Laboratory are developing a Next Generation Nuclear Plant (NGNP) to serve as a demonstration of state-of-the-art nuclear technology. The purpose of the demonstration is two fold 1) efficient low cost energy generation and 2) hydrogen production. Although a next generation plant could be developed as a single-purpose facility, early designs are expected to be dual-purpose. While hydrogen production and advanced energy cycles are still in its early stages of development, research towards coupling a high temperature reactor, electrical generation and hydrogen production is under way. Many aspects of the NGNP must be researched and developed in order to make recommendations on the final design of the plant. Parameters such as working conditions, cycle components, working fluids, and power conversion unit configurations must be understood. Three configurations of the power conversion unit were demonstrated in this study. A three-shaft design with 3 turbines and 4 compressors, a combined cycle with a Brayton top cycle and a Rankine bottoming cycle, and a reheated cycle with 3 stages of reheat were investigated. An intermediate heat transport loop for transporting process heat to a High Temperature Steam Electrolysis (HTSE) hydrogen production plant was used. Helium, CO2, and an 80% nitrogen, 20% helium mixture (by weight) were studied to determine the best working fluid in terms cycle efficiency and development cost. In each of these configurations the relative component size were estimated for the different working fluids. The relative size of the turbomachinery was measured by comparing the power input/output of the component. For heat exchangers the volume was computed and compared. Parametric studies away from the baseline values of the three-shaft and combined cycles were performed to determine the effect of varying conditions in the cycle. This gives some insight into the sensitivity of these cycles to various

  13. Output power maximization of low-power wind energy conversion systems revisited: Possible control solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vlad, Ciprian; Munteanu, Iulian; Bratcu, Antoneta Iuliana; Ceanga, Emil [' ' Dunarea de Jos' ' University of Galati, 47, Domneasca, 800008-Galati (Romania)

    2010-02-15

    This paper discusses the problem of output power maximization for low-power wind energy conversion systems operated in partial load. These systems are generally based on multi-polar permanent-magnet synchronous generators, who exhibit significant efficiency variations over the operating range. Unlike the high-power systems, whose mechanical-to-electrical conversion efficiency is high and practically does not modify the global optimum, the low-power systems global conversion efficiency is affected by the generator behavior and the electrical power optimization is no longer equivalent with the mechanical power optimization. The system efficiency has been analyzed by using both the maxima locus of the mechanical power versus the rotational speed characteristics, and the maxima locus of the electrical power delivered versus the rotational speed characteristics. The experimental investigation has been carried out by using a torque-controlled generator taken from a real-world wind turbine coupled to a physically simulated wind turbine rotor. The experimental results indeed show that the steady-state performance of the conversion system is strongly determined by the generator behavior. Some control solutions aiming at maximizing the energy efficiency are envisaged and thoroughly compared through experimental results. (author)

  14. Output power maximization of low-power wind energy conversion systems revisited: Possible control solutions

    International Nuclear Information System (INIS)

    Vlad, Ciprian; Munteanu, Iulian; Bratcu, Antoneta Iuliana; Ceanga, Emil

    2010-01-01

    This paper discusses the problem of output power maximization for low-power wind energy conversion systems operated in partial load. These systems are generally based on multi-polar permanent-magnet synchronous generators, who exhibit significant efficiency variations over the operating range. Unlike the high-power systems, whose mechanical-to-electrical conversion efficiency is high and practically does not modify the global optimum, the low-power systems global conversion efficiency is affected by the generator behavior and the electrical power optimization is no longer equivalent with the mechanical power optimization. The system efficiency has been analyzed by using both the maxima locus of the mechanical power versus the rotational speed characteristics, and the maxima locus of the electrical power delivered versus the rotational speed characteristics. The experimental investigation has been carried out by using a torque-controlled generator taken from a real-world wind turbine coupled to a physically simulated wind turbine rotor. The experimental results indeed show that the steady-state performance of the conversion system is strongly determined by the generator behavior. Some control solutions aiming at maximizing the energy efficiency are envisaged and thoroughly compared through experimental results.

  15. Switching-mode Audio Power Amplifiers with Direct Energy Conversion

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    has been replaced with a high frequency AC link. When compared to the conventional Class D amplifiers with a separate DC power supply, the proposed single conversion stage amplifier provides simple and compact solution with better efficiency and higher level of integration, leading to reduced...

  16. Direct conversion of infrared radiant energy for space power applications

    Science.gov (United States)

    Finke, R. C.

    1982-01-01

    A proposed technology to convert the earth radiant energy (infrared albedo) for spacecraft power is presented. The resultant system would eliminate energy storage requirements and simplify the spacecraft design. The design and performance of a infrared rectenna is discussed.

  17. Advanced, High Power, Next Scale, Wave Energy Conversion Device

    Energy Technology Data Exchange (ETDEWEB)

    Mekhiche, Mike [Principal Investigator; Dufera, Hiz [Project Manager; Montagna, Deb [Business Point of Contact

    2012-10-29

    The project conducted under DOE contract DE‐EE0002649 is defined as the Advanced, High Power, Next Scale, Wave Energy Converter. The overall project is split into a seven‐stage, gated development program. The work conducted under the DOE contract is OPT Stage Gate III work and a portion of Stage Gate IV work of the seven stage product development process. The project effort includes Full Concept Design & Prototype Assembly Testing building on our existing PowerBuoy technology to deliver a device with much increased power delivery. Scaling‐up from 150kW to 500kW power generating capacity required changes in the PowerBuoy design that addressed cost reduction and mass manufacturing by implementing a Design for Manufacturing (DFM) approach. The design changes also focused on reducing PowerBuoy Installation, Operation and Maintenance (IO&M) costs which are essential to reducing the overall cost of energy. In this design, changes to the core PowerBuoy technology were implemented to increase capability and reduce both CAPEX and OPEX costs. OPT conceptually envisaged moving from a floating structure to a seabed structure. The design change from a floating structure to seabed structure would provide the implementation of stroke‐ unlimited Power Take‐Off (PTO) which has a potential to provide significant power delivery improvement and transform the wave energy industry if proven feasible.

  18. Summary of State-of-the-Art Power Conversion Systems for Energy Storage Applications

    Energy Technology Data Exchange (ETDEWEB)

    Atcitty, S.; Gray-Fenner, A.; Ranade, S.

    1998-09-01

    The power conversion system (PCS) is a vital part of many energy storage systems. It serves as the interface between the storage device, an energy source, and an AC load. This report summarizes the results of an extensive study of state-of-the-art power conversion systems used for energy storage applications. The purpose of the study was to investigate the potential for cost reduction and performance improvement in these power conversion systems and to provide recommendations for fiture research and development. This report provides an overview of PCS technology, a description of several state-of-the-art power conversion systems and how they are used in specific applications, a summary of four basic configurations for l:he power conversion systems used in energy storage applications, a discussion of PCS costs and potential cost reductions, a summary of the stancku-ds and codes relevant to the technology, and recommendations for future research and development.

  19. Elements of energy conversion

    CERN Document Server

    Russell, Charles R

    2013-01-01

    Elements of Energy Conversion brings together scattered information on the subject of energy conversion and presents it in terms of the fundamental thermodynamics that apply to energy conversion by any process. Emphasis is given to the development of the theory of heat engines because these are and will remain most important power sources. Descriptive material is then presented to provide elementary information on all important energy conversion devices. The book contains 10 chapters and opens with a discussion of forms of energy, energy sources and storage, and energy conversion. This is foll

  20. Dimensionless Energy Conversion Characteristics of an Air-Powered Hydraulic Vehicle

    OpenAIRE

    Dongkai Shen; Qilong Chen; Yixuan Wang

    2018-01-01

    Due to the advantages of resource conservation and less exhaust emissions, compressed air-powered vehicle has attracted more and more attention. To improve the power and efficiency of air-powered vehicle, an air-powered hydraulic vehicle was proposed. As the main part of the air-powered hydraulic vehicles, HP transformer (short for Hydropneumatic transformer) is used to convert the pneumatic power to higher hydraulic power. In this study, to illustrate the energy conversion characteristics of...

  1. Offshore Hydrokinetic Energy Conversion for Onshore Power Generation

    Science.gov (United States)

    Jones, Jack A.; Chao, Yi

    2009-01-01

    Design comparisons have been performed for a number of different tidal energy systems, including a fully submerged, horizontal-axis electro-turbine system, similar to Verdant Tidal Turbines in New York's East River, a platform-based Marine Current Turbine, now operating in Northern Ireland's Strangford Narrows, and the Rotech Lunar Energy system, to be installed off the South Korean Coast. A fourth type of tidal energy system studied is a novel JPL/Caltech hydraulic energy transfer system that uses submerged turbine blades which are mechanically attached to adjacent high-pressure pumps, instead of to adjacent electrical turbines. The generated highpressure water streams are combined and transferred to an onshore hydroelectric plant by means of a closed-cycle pipeline. The hydraulic energy transfer system was found to be cost competitive, and it allows all electronics to be placed onshore, thus greatly reducing maintenance costs and corrosion problems. It also eliminates the expenses of conditioning and transferring multiple offshore power lines and of building offshore platforms embedded in the sea floor.

  2. Self-oscillating modulators for direct energy conversion audio power amplifiers

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    Direct energy conversion audio power amplifier represents total integration of switching-mode power supply and Class D audio power amplifier into one compact stage, achieving high efficiency, high level of integration, low component count and eventually low cost. This paper presents how self-oscillating...

  3. Energy conversion alternatives study

    Science.gov (United States)

    Shure, L. T.

    1979-01-01

    Comparison of coal based energy systems is given. Study identifies and compares various advanced energy conversion systems using coal or coal derived fuels for baselaoad electric power generation. Energy Conversion Alternatives Study (ECAS) reports provede government, industry, and general public with technically consistent basis for comparison of system's options of interest for fossilfired electric-utility application.

  4. Solid State Energy Conversion for Deep Space Power

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermophotovoltaic (TPV) devices employed in static radioisotope generators show great promise for highly efficient, reliable, and resilient power generation for...

  5. Thermophotovoltaic Energy Conversion in Space Nuclear Reactor Power Systems

    National Research Council Canada - National Science Library

    Presby, Andrew L

    2004-01-01

    .... This has potential benefits for space nuclear reactor power systems currently in development. The primary obstacle to space operation of thermophotovoltaic devices appears to be the low heat rejection temperatures which necessitate large radiator areas...

  6. Relation of the second law of thermodynamics to the power conversion of energy fluctuations

    International Nuclear Information System (INIS)

    Yater, J.C.

    1979-01-01

    The relation of the second law of thermodynamics to the power conversion of fluctuation energy is analyzed using the master equation of the model for the conversion circuit. The performance equation for independent particles shows that the power-conversion performance is given by the second law both for classical and quantum-effect diodes. The relation of the second law to power-conversion models based on the theoretical and experimental results for diode performance for interacting particles exhibiting many-body, multiparticle, or other anomalous and excess-current effects is examined. The performance equations are derived from the master equation for models for interacting particles to determine the conditions required by the second law for power conversion. These conditions are given in terms of the distribution throughout the power-conversion circuit for all the parameters that determine the particle and multiparticle barrier-crossing probability such as the effective mass and spectral density functions. Circuits for spectroscopic measurements for power-conversion circuits with interacting particles are noted. Using selected experimental values for the diode nonlinearity factors in these circuits, open circuit voltages are computed that are not predicted by the second law of thermodynamics

  7. Understanding Power Electronics and Electrical Machines in Multidisciplinary Wind Energy Conversion System Courses

    Science.gov (United States)

    Duran, M. J.; Barrero, F.; Pozo-Ruz, A.; Guzman, F.; Fernandez, J.; Guzman, H.

    2013-01-01

    Wind energy conversion systems (WECS) nowadays offer an extremely wide range of topologies, including various different types of electrical generators and power converters. Wind energy is also an application of great interest to students and with a huge potential for engineering employment. Making WECS the main center of interest when teaching…

  8. Audio power amplifier techniques with energy efficient power conversion. Vol. 1

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Karsten

    1998-04-01

    A fundamental study of both analog and digital pulse modulation methods is carried out. A novel class of multi-level pulse modulation methods - Phase Shifted Carrier Pulse Width Modulation (PSCPWM) - is introduced and show to have several advantageous features, primarily caused by the much improved synthesis of the modulating signal. Enhanced digital pulse modulation methods for digital Pulse Modulation Amplifier (PMA) systems are investigated, and a simple methodology for digital PWM modulator synthesis is devised. It is concluded, that the modulator performance is not a limitation in the system, regardless of the domain of modulator implementation. Power conversion in PMA systems is adressed from the perspective of both linearity and efficienty optimization. Based on detailed studies of the distortion mechanisms in the power conversion stage it is concluded, that this is the fundamental limitation on system performance due to several physical limitations. The analysis of general power stage efficiency concludes that dramatic improvements in energy efficiency are possible with PMA systems that are optimized for efficiency. A control system design methodology is devised as a platform for synthesis of robust control systems. Investigations of three fundamental control structures show that even simple control systems offer a remarkable value, although the considered topologies also have their limitations which is verified by practical evaluation in hardware. A novel control method is introduced - Multivariable Enhanced Cascade Control (MECC). MECC provides flexible control over all essential system parameters and is furthermore simple in realization. Practical evaluation of a MECC based PMA shows state-of-the-art performance. The application of non-linear control methods is investigated with the introduction of an enhanced non-linear control/modulator topology. Although the non-linear controller is theoretically interesting, the method proves to suffer from various

  9. Rectenna System Design. [energy conversion solar power satellites

    Science.gov (United States)

    Woodcock, G. R.; Andryczyk, R. W.

    1980-01-01

    The fundamental processes involved in the operation of the rectenna system designed for the solar power satellite system are described. The basic design choices are presented based on the desired microwave rf field concentration prior to rectification and based on the ground clearance requirements for the rectenna structure. A nonconcentrating inclined planar panel with a 2 meter minimum clearance configuration is selected as a representative of the typical rectenna.

  10. A proposed strategy for power optimization of a wind energy conversion system connected to the grid

    International Nuclear Information System (INIS)

    Taraft, S.; Rekioua, D.; Aouzellag, D.; Bacha, S.

    2015-01-01

    Highlights: • Wind energy conversion based doubly fed induction generator controlled by matrix converter. • Operation at both sub and super-synchronous regions is possible with the proposed drive system. • Double the power generated by the DFIG at a twice of speed rated. • Sliding mode control is used to achieve active and reactive power control. - Abstract: Many strategies have been developed in last decade to optimize power extracted from wind energy conversion system where many of them can produce only 30% more than the rated power. With the considered strategy, the generated wind power can reach twice its nominal value using a fast and reliable fully rugged electrical control. Indeed, by employing a suitable control technique where the produced power in super-synchronous mode is derived from both the stator and the rotor. Also, the rotor provided power in this case grows up 100% comparing to stator rated power. However, this solution permits to maintain the wind energy conversion system operation in its stable area. The considered system consists of a double fed induction generator whose stator is connected directly to the grid and its rotor is supplied by matrix converter. In this paper, the sliding mode approach to achieve active and reactive power control is used. This latter is combined with de Perturbation and Observation Maximum Power Point Tracking used in the second operation zone. The obtained simulations results are assessed and carried out using Matlab/Simulink package and show the performance and the effectiveness of the proposed control

  11. A novel MPPT method for enhancing energy conversion efficiency taking power smoothing into account

    International Nuclear Information System (INIS)

    Liu, Jizhen; Meng, Hongmin; Hu, Yang; Lin, Zhongwei; Wang, Wei

    2015-01-01

    Highlights: • We discuss the disadvantages of conventional OTC MPPT method. • We study the relationship between enhancing efficiency and power smoothing. • The conversion efficiency is enhanced and the volatility of power is suppressed. • Small signal analysis is used to verify the effectiveness of proposed method. - Abstract: With the increasing capacity of wind energy conversion system (WECS), the rotational inertia of wind turbine is becoming larger. And the efficiency of energy conversion is significantly reduced by the large inertia. This paper proposes a novel maximum power point tracking (MPPT) method to enhance the efficiency of energy conversion for large-scale wind turbine. Since improving the efficiency may increase the fluctuations of output power, power smoothing is considered as the second control objective. A T-S fuzzy inference system (FIS) is adapted to reduce the fluctuations according to the volatility of wind speed and accelerated rotor speed by regulating the compensation gain. To verify the effectiveness, stability and good dynamic performance of the new method, mechanism analyses, small signal analyses, and simulation studies are carried out based on doubly-fed induction generator (DFIG) wind turbine, respectively. Study results show that both the response speed and the efficiency of proposed method are increased. In addition, the extra fluctuations of output power caused by the high efficiency are reduced effectively by the proposed method with FIS

  12. Power management of a wind energy conversion system equipped by DFIG

    Directory of Open Access Journals (Sweden)

    Iman Zangiabadi

    2016-06-01

    Full Text Available Today wind is one of the attractive points of energy area which has got the noticeable amount of investment and studies in this field. Considering the importance of the wind energy and its potentials as one of the renewable energy sources, in this paper managing the production of active and reactive powers of a wind energy conversion system equipped with DFIG has been studied. In this regard, a structure based on vector control is offered to achieve an independent control of active and reactive powers. The strategy of managing the production of active and reactive power is applied to network by rotor side converter of a DFIG. The production of active power according to the maximum power point taking (MPPT strategy to get a maximum power of the wind energy has been done and also improvement of power quality based on strategies of power factor correction and harmonics reduction have been arranged for a power network. In order to evaluate the performance of the proposed method, a DFIG connected with a power network in different conditions of the reactive load has been simulated by MATLAB software.Obviously, the results state the proper operation of the power control of wind energy converting system , improvement of the network power factor, and Reduction of harmonic current of network based on the proposed method.

  13. Power converter topologies for wind energy conversion systems: Integrated modeling, control strategy and performance simulation

    Energy Technology Data Exchange (ETDEWEB)

    Melicio, R.; Catalao, J.P.S. [Department of Electromechanical Engineering, University of Beira Interior, R. Fonte do Lameiro, 6201-001 Covilha (Portugal); Mendes, V.M.F. [Department of Electrical Engineering and Automation, Instituto Superior de Engenharia de Lisboa, R. Conselheiro Emidio Navarro, 1950-062 Lisbon (Portugal)

    2010-10-15

    This paper presents new integrated model for variable-speed wind energy conversion systems, considering a more accurate dynamic of the wind turbine, rotor, generator, power converter and filter. Pulse width modulation by space vector modulation associated with sliding mode is used for controlling the power converters. Also, power factor control is introduced at the output of the power converters. Comprehensive performance simulation studies are carried out with matrix, two-level and multilevel power converter topologies in order to adequately assert the system performance. Conclusions are duly drawn. (author)

  14. Self-oscillating modulators for direct energy conversion audio power amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    Direct energy conversion audio power amplifier represents total integration of switching-mode power supply and Class D audio power amplifier into one compact stage, achieving high efficiency, high level of integration, low component count and eventually low cost. This paper presents how self-oscillating modulators can be used with the direct switching-mode audio power amplifier to improve its performance by providing fast hysteretic control with high power supply rejection ratio, open-loop stability and high bandwidth. Its operation is thoroughly analyzed and simulated waveforms of a prototype amplifier are presented. (au)

  15. Electrochemical solar energy conversion

    International Nuclear Information System (INIS)

    Gerischer, H.

    1991-01-01

    The principles of solar energy conversion in photoelectrochemical cells are briefly reviewed. Cells for the generation of electric power and for energy storage in form of electrochemical energy are described. These systems are compared with solid state photovoltaic devices, and the inherent difficulties for the operation of the electrochemical systems are analyzed. (author). 28 refs, 10 figs

  16. A Power Supply System with ZVS and Current-Doubler Features for Hybrid Renewable Energy Conversion

    Directory of Open Access Journals (Sweden)

    Jye-Chau Su

    2013-09-01

    Full Text Available In this paper, a power supply system for hybrid renewable energy conversion is proposed, which can process PV (photovoltaic power and wind-turbine energy simultaneously for step-down voltage and high current applications. It is a dual-input converter and mainly contains a PV energy source, a wind turbine energy source, a zero-voltage-switching (ZVS forward converter, and a current-doubler rectifier. The proposed power supply system has the following advantages: (1 PV-arrays and wind-energy sources can alternatively deliver power to the load during climate or season alteration; (2 maximum power point tracking (MPPT can be accomplished for both different kinds of renewable-energy sources; (3 ZVS and synchronous rectification techniques for the active switches of the forward converter are embedded so as to reduce switching and conducting losses; and (4 electricity isolation is naturally obtained. To achieve an optimally dynamic response and to increase control flexibility, a digital signal processor (DSP is investigated and presented to implement MPPT algorithm and power regulating scheme. Finally, a 240 W prototype power supply system with ZVS and current-doubler features to deal with PV power and wind energy is built and implemented. Experimental results are presented to verify the performance and the feasibility of the proposed power supply system.

  17. Thermally Driven Transport and Relaxation Switching Self-Powered Electromagnetic Energy Conversion.

    Science.gov (United States)

    Cao, Maosheng; Wang, Xixi; Cao, Wenqiang; Fang, Xiaoyong; Wen, Bo; Yuan, Jie

    2018-06-07

    Electromagnetic energy radiation is becoming a "health-killer" of living bodies, especially around industrial transformer substation and electricity pylon. Harvesting, converting, and storing waste energy for recycling are considered the ideal ways to control electromagnetic radiation. However, heat-generation and temperature-rising with performance degradation remain big problems. Herein, graphene-silica xerogel is dissected hierarchically from functions to "genes," thermally driven relaxation and charge transport, experimentally and theoretically, demonstrating a competitive synergy on energy conversion. A generic approach of "material genes sequencing" is proposed, tactfully transforming the negative effects of heat energy to superiority for switching self-powered and self-circulated electromagnetic devices, beneficial for waste energy harvesting, conversion, and storage. Graphene networks with "well-sequencing genes" (w = P c /P p > 0.2) can serve as nanogenerators, thermally promoting electromagnetic wave absorption by 250%, with broadened bandwidth covering the whole investigated frequency. This finding of nonionic energy conversion opens up an unexpected horizon for converting, storing, and reusing waste electromagnetic energy, providing the most promising way for governing electromagnetic pollution with self-powered and self-circulated electromagnetic devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. On the Development of Fuel-Free Power Supply Sources on Pneumatic Energy Conversion Principles

    Science.gov (United States)

    Son, E. E.; Nikolaev, V. G.; Kudryashov, Yu. I.; Nikolaev, V. V.

    2017-12-01

    The article is devoted to the evaluation of capabilities and problems of creation of fuel-free power supply of isolated and autonomous Russian consumers of low (up to several hundreds kW) power based on the joint use of wind power plants and progressive systems of pneumatic accumulation and conversion of energy. The basic and functional schemes and component structure of the system prototype are developed and proposed, the evaluations of the expected technical and economic indicators of system are presented, and the ways of its further practical implementation are planned.

  19. Highly efficient power system based on direct fission fragment energy conversion utilizing magnetic collimation

    International Nuclear Information System (INIS)

    Tsvetkov, Pavel V.; Hart, Ron R.; Parish, Theodore A.

    2003-01-01

    The present study was focused on developing a technologically feasible power system that is based on direct fission fragment energy conversion utilizing magnetic collimation. The new concept is an attempt to combine several advantageous design solutions, which have been proposed for application in both fission and fusion reactors, into one innovative system that can offer exceptional energy conversion efficiency. The analysis takes into consideration a wide range of operational aspects including fission fragment escape from the fuel, collimation, collection, criticality, long-term performance, energy conversion efficiency, heat removal, and safety characteristics. Specific characteristics of the individual system components and the entire system are evaluated. Consistent analysis and evaluation of the technological feasibility of the concept were achieved using state-of-the-art computer codes that allowed realistic and consistent modeling. The calculated energy conversion efficiencies for the presented designs without a thermodynamic cycle and with the heavy water cycle are 52% and 62%, respectively. The analysis indicates that efficiencies up to 90% are potentially achievable. (author)

  20. Wind energy conversion system

    Science.gov (United States)

    Longrigg, Paul

    1987-01-01

    The wind energy conversion system includes a wind machine having a propeller connected to a generator of electric power, the propeller rotating the generator in response to force of an incident wind. The generator converts the power of the wind to electric power for use by an electric load. Circuitry for varying the duty factor of the generator output power is connected between the generator and the load to thereby alter a loading of the generator and the propeller by the electric load. Wind speed is sensed electro-optically to provide data of wind speed upwind of the propeller, to thereby permit tip speed ratio circuitry to operate the power control circuitry and thereby optimize the tip speed ratio by varying the loading of the propeller. Accordingly, the efficiency of the wind energy conversion system is maximized.

  1. Evaluation of maximum power point tracking in hydrokinetic energy conversion systems

    Directory of Open Access Journals (Sweden)

    Jahangir Khan

    2015-11-01

    Full Text Available Maximum power point tracking is a mature control issue for wind, solar and other systems. On the other hand, being a relatively new technology, detailed discussion on power tracking of hydrokinetic energy conversion systems are generally not available. Prior to developing sophisticated control schemes for use in hydrokinetic systems, existing know-how in wind or solar technologies can be explored. In this study, a comparative evaluation of three generic classes of maximum power point scheme is carried out. These schemes are (a tip speed ratio control, (b power signal feedback control, and (c hill climbing search control. In addition, a novel concept for maximum power point tracking: namely, extremum seeking control is introduced. Detailed and validated system models are used in a simulation environment. Potential advantages and drawbacks of each of these schemes are summarised.

  2. Fully solar-powered photoelectrochemical conversion for simultaneous energy storage and chemical sensing.

    Science.gov (United States)

    Wang, Yongcheng; Tang, Jing; Peng, Zheng; Wang, Yuhang; Jia, Dingsi; Kong, Biao; Elzatahry, Ahmed A; Zhao, Dongyuan; Zheng, Gengfeng

    2014-06-11

    We report the development of a multifunctional, solar-powered photoelectrochemical (PEC)-pseudocapacitive-sensing material system for simultaneous solar energy conversion, electrochemical energy storage, and chemical detection. The TiO2 nanowire/NiO nanoflakes and the Si nanowire/Pt nanoparticle composites are used as photoanodes and photocathodes, respectively. A stable open-circuit voltage of ∼0.45 V and a high pseudocapacitance of up to ∼455 F g(-1) are obtained, which also exhibit a repeating charging-discharging capability. The PEC-pseudocapacitive device is fully solar powered, without the need of any external power supply. Moreover, this TiO2 nanowire/NiO nanoflake composite photoanode exhibits excellent glucose sensitivity and selectivity. Under the sun light illumination, the PEC photocurrent shows a sensitive increase upon different glucose additions. Meanwhile in the dark, the open-circuit voltage of the charged pseudocapacitor also exhibits a corresponding signal over glucose analyte, thus serving as a full solar-powered energy conversion-storage-utilization system.

  3. Program THEK energy production units of average power and using thermal conversion of solar radiation

    Science.gov (United States)

    1978-01-01

    General studies undertaken by the C.N.R.S. in the field of solar power plants have generated the problem of building energy production units in the medium range of electrical power, in the order of 100 kW. Among the possible solutions, the principle of the use of distributed heliothermal converters has been selected as being, with the current status of things, the most advantageous solution. This principle consists of obtaining the conversion of concentrated radiation into heat by using a series of heliothermal conversion modules scattered over the ground; the produced heat is collected by a heat-carrying fluid circulating inside a thermal loop leading to a device for both regulation and storage.

  4. The alkali metal thermoelectric converter /AMTEC/ - A new direct energy conversion technology for aerospace power

    Science.gov (United States)

    Bankston, C. P.; Cole, T.; Jones, R.; Ewell, R.

    1982-01-01

    A thermally regenerative electrochemical device for the direct conversion of heat to electrical energy, the alkali metal thermoelectric converter (AMTEC), is characterized by potential efficiencies on the order of 15-40% and possesses no moving parts, making it a candidate for space power system applications. Device conversion efficiency is projected on the basis of experimental voltage vs current curves exhibiting power densities of 0.7 W/sq cm and measured electrode efficiencies of up to 40%. Preliminary radiative heat transfer measurements presented may be used in an investigation of methods for the reduction of AMTEC parasitic radiation losses. AMTEC assumes heat input and rejection temperatures of 900-1300 K and 400-800 K, respectively. The working fluid is liquid sodium, and the porous electrode employed is of molybdenum.

  5. Novel high efficient speed sensorless controller for maximum power extraction from wind energy conversion systems

    International Nuclear Information System (INIS)

    Fathabadi, Hassan

    2016-01-01

    Highlights: • Novel sensorless MPPT technique without drawbacks of other sensor/sensorless methods. • Tracking the actual MPP of WECSs, no tracking the MPP of their wind turbines. • Actually extracting the highest output power from WECSs. • Novel MPPT technique having the MPPT efficiency more than 98.5% for WECSs. • Novel MPPT technique having short convergence time for WECSs. - Abstract: In this study, a novel high accurate sensorless maximum power point tracking (MPPT) method is proposed. The technique tracks the actual maximum power point of a wind energy conversion system (WECS) at which maximum output power is extracted from the system, not the maximum power point of its wind turbine at which maximum mechanical power is obtained from the turbine, so it actually extracts the highest output power from the system. The technique only uses input voltage and current of the converter used in the system, and neither needs any speed sensors (anemometer and tachometer) nor has the drawbacks of other sensor/sensorless based MPPT methods. The technique has been implemented as a MPPT controller by constructing a WECS. Theoretical results, the technique performance, and its advantages are validated by presenting real experimental results. The real static-dynamic response of the MPPT controller is experimentally obtained that verifies the proposed MPPT technique high accurately extracts the highest instant power from wind energy conversion systems with the MPPT efficiency of more than 98.5% and a short convergence time that is only 25 s for the constructed system having a total inertia and friction coefficient of 3.93 kg m 2 and 0.014 N m s, respectively.

  6. Dimensionless Energy Conversion Characteristics of an Air-Powered Hydraulic Vehicle

    Directory of Open Access Journals (Sweden)

    Dongkai Shen

    2018-02-01

    Full Text Available Due to the advantages of resource conservation and less exhaust emissions, compressed air-powered vehicle has attracted more and more attention. To improve the power and efficiency of air-powered vehicle, an air-powered hydraulic vehicle was proposed. As the main part of the air-powered hydraulic vehicles, HP transformer (short for Hydropneumatic transformer is used to convert the pneumatic power to higher hydraulic power. In this study, to illustrate the energy conversion characteristics of air-powered hydraulic vehicle, dimensionless mathematical model of the vehicle’s working process was set up. Through experimental study on the vehicle, the dimensionless model was verified. Through simulation study on the vehicle, the following can be obtained: firstly, the increase of the hydraulic chamber orifice and the area ratio of the pistons can lead to a higher output power, while output pressure is just the opposite. Moreover, the increase of the output pressure and the aperture of the hydraulic chamber can lead to a higher efficiency, while area ratio of the pistons played the opposite role. This research can be referred to in the performance and design optimization of the HP transformers.

  7. Line filter design of parallel interleaved VSCs for high power wind energy conversion systems

    DEFF Research Database (Denmark)

    Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus

    2015-01-01

    The Voltage Source Converters (VSCs) are often connected in parallel in a Wind Energy Conversion System (WECS) to match the high power rating of the modern wind turbines. The effect of the interleaved carriers on the harmonic performance of the parallel connected VSCs is analyzed in this paper...... limit. In order to achieve the desired filter performance with optimal values of the filter parameters, the use of a LC trap branch with the conventional LCL filter is proposed. The expressions for the resonant frequencies of the proposed line filter are derived and used in the design to selectively...

  8. A comparison of energy conversion systems for meeting the power requirements of manned rover for Mars missions

    International Nuclear Information System (INIS)

    El-Genk, M.S.; Morley, N.; Cataldo, R.; Bloomfield, H.

    1990-01-01

    Minimizing system mass for interplanetary missions is of utmost importance in order to keep launch cost within reasonable bounds. For a manned Mars rover, powered by a nuclear reactor power system, the choice of the energy conversion system can play a significant role in lowering the overall system mass. Not only is the mass of the conversion unit affected by the choice, but also the masses of the reactor core, waste heat rejection system, and the radiation shield which are strongly influenced by the system conversion efficiency and operating condition. Several types of conversion systems are of interest for a nuclear reactor Mars manned application. These conversion systems include: free piston Stirling engines, He/XE closed Brayton cycle (CBC), CO 2 open Brayton, and SiGe/GaP thermoelectric. Optimization studies are conducted to determine the impact of the conversion system on the overall mass of the nuclear power system as well as the mobility power requirement of the Rover vehicle

  9. Direct Conversion of Energy.

    Science.gov (United States)

    Corliss, William R.

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Direct energy conversion involves energy transformation without moving parts. The concepts of direct and dynamic energy conversion plus the laws governing energy conversion are investigated. Among the topics…

  10. EDITORIAL: The Fourth International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2004)

    Science.gov (United States)

    Tanaka, Shuji; Toriyama, Toshiyuki

    2005-09-01

    This special issue of the Journal of Micromechanics and Microengineering features papers selected from the Fourth International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2004). The workshop was held in Kyoto, Japan, on 28-30 November 2004, by The Ritsumeikan Research Institute of Micro System Technology in cooperation with The Global Emerging Technology Institute, The Institute of Electrical Engineers of Japan, The Sensors and Micromachines Society, The Micromachine Center and The Kyoto Nanotech Cluster. Power MEMS is one of the newest categories of MEMS, which encompasses microdevices and microsystems for power generation, energy conversion and propulsion. The first concept of power MEMS was proposed in the late 1990s by Epstein's group at the Massachusetts Institute of Technology, where they continue to study MEMS-based gas turbine generators. Since then, the research and development of power MEMS have been promoted by the need for compact power sources with high energy and power density. Since its inception, power MEMS has expanded to include not only various MEMS-based power generators but also small energy machines and microdevices for macro power generators. At the last workshop, various devices and systems, such as portable fuel cells and their peripherals, micro and small turbo machinery, energy harvesting microdevices, and microthrusters, were presented. Their power levels vary from ten nanowatts to hundreds of watts, spanning ten orders of magnitude. The first PowerMEMS workshop was held in 2000 in Sendai, Japan, and consisted of only seven invited presentations. The workshop has grown since then, and in 2004 there were 5 invited, 20 oral and 29 poster presentations. From the 54 papers in the proceedings, 12 papers have been selected for this special issue. I would like to express my appreciation to the members of the Organizing Committee and Technical Program Committee. This special issue was

  11. Permanent Magnet Synchronous Generator Driven Wind Energy Conversion System Based on Parallel Active Power Filter

    Directory of Open Access Journals (Sweden)

    FERDI Brahim

    2014-05-01

    Full Text Available This paper proposes a novel application of the instantaneous P-Q theory in a wind energy conversion system (WECS. The proposed WECS is formed by permanent magnet synchronous generator (PMSG wind turbine system connected to the grid through parallel active power filter (PAPF. PAPF uses the generated wind energy to feed loads connected at the point of common coupling (PPC, compensates current harmonics and injects the excess of this energy into the grid using P-Q theory as control method. To demonstrate the feasibility and the performance of the proposed control scheme, simulation of this wind system has been realized using MATLAB/SIMULINK software. Simulation results show the accuracy and validity of the proposed control scheme for the PMSGPAPF system.

  12. HYDROKINETIC ENERGY CONVERSION SYSTEMS: PROSPECTS ...

    African Journals Online (AJOL)

    eobe

    Hydrokinetic energy conversion systems utilize the kinetic energy of flowing water bodies with little or no head to generate ... generator. ... Its principle of operation is analogous to that of wind ..... Crisis-solar and wind power systems, 2009,.

  13. Ocean energy conversion - A reality

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.

    -depth analysis of application and achievements of OTEC, tidal energy, impact of astronomical forces on tide, prospects of tidal power plants, wave energy conversion and its mathematical approach for both linear and non-linear waves, economic viability, problems...

  14. Solar driven electrochromic photoelectrochemical fuel cells for simultaneous energy conversion, storage and self-powered sensing.

    Science.gov (United States)

    Wang, Yanhu; Zhang, Lina; Cui, Kang; Xu, Caixia; Li, Hao; Liu, Hong; Yu, Jinghua

    2018-02-15

    One solar-driven electrochromic photoelectrochemical fuel cell (PFC) with highly efficient energy conversion and storage is easily constructed to achieve quantitative self-powered sensing. Layered bismuth oxyiodide-zinc oxide nanorod arrays (ZnO@BiOI NRA) with a core/shell p-n heterostructure are fabricated as the photoanode with electrochromic Prussian blue (PB) as the cathode. The core/shell p-n heterostructure for the ZnO@BiOI photoanode can effectively boost the photoelectrochemical (PEC) performance through the improvement of photon absorption and charge carrier separation. The optimal assembled PFC yields an open-circuit voltage (V OC ) of 0.48 V with the maximum power output density (P max ) as high as 155 μW cm -2 upon illumination. Benefitting from the interactive color-changing behavior of PB, the cathode not only exhibits cathodic catalytic activity in the PFC but also serves as an electrochromic display for self-powered sensing. The as-constructed PFC possesses multiple readable signal output nanochannels through the maximum power output density (P max ) of the PFC or the color change of PB. Meanwhile, the dual-signal-output makes the as-constructed self-powered sensor highly available in various operations demands with the enhanced reliability. With the advantages of high efficiency of PFCs, unique assay ability, and broad environmental suitability, the constructed self-powered platform shows broad application prospects as an integrated smart analytical device.

  15. A Novel Maximum Power Point Tracking Control for Permanent Magnet Direct Drive Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2012-05-01

    Full Text Available This paper proposes a novel optimal current given (OCG maximum power point tracking (MPPT control strategy based on the theory of power feedback and hill climb searching (HCS for a permanent magnet direct drive wind energy conversion system (WECS. The presented strategy not only has the advantages of not needing the wind speed and wind turbine characteristics of the traditional HCS method, but it also improves the stability and accuracy of MPPT by estimating the exact loss torque. The OCG MPPT control strategy is first carried out by simulation, then an experimental platform based on the dSPACE1103 controller is built and a 5.5 kW permanent magnet synchronous generator (PMSG is tested. Furthermore, the proposed method is compared experimentally with the traditional optimum tip speed ratio (TSR MPPT control. The experiments verify the effectiveness of the proposed OCG MPPT strategy and demonstrate its better performance than the traditional TSR MPPT control.

  16. Photovoltaic energy conversion and wind power plants creating new jobs; Arbeitsplaetze durch Photovoltaik und Windenergie

    Energy Technology Data Exchange (ETDEWEB)

    Hille, G.; Hoffmann, V.U. [Fraunhofer ISE, Freiburg (Germany); Dienhart, H.; Langniss, O.; Nitsch, J. [DLR, Stuttgart (Germany)

    1997-12-01

    Experts are unanimous that opening up new markets through innovative technologies will be the successful strategy for reversing the upward trend of unemployment in Germany. This approach puts renewable energy sources into the foreground, as enhanced use of wind power and photovoltaic energy conversion will no doubt create new jobs. These technologies will, however, require favourable regulatory framework conditions in order to become a significant force in combatting unemployment. (orig./CB) [Deutsch] Es gilt unter Experten als sicher, dass eine Umkehr am Arbeitsmarkt nur dadurch zu schaffen ist, dass innovative Technologien genutzt und damit neue Maerkte erschlossen werden. Demnach koennte etwa dem Ausbau der regenerativen Energietraeger Wind und Photovoltaik zur Schaffung zukunftssicherer Arbeitsplaetze eine grosse Bedeutung zukommen. Einen ernstzunehmenden Beitrag im Kampf gegen die Arbeitslosigkeit koennen diese Technologien allerdings nur unter bestimmten Rahmenbedingungen leisten. (orig./RHM)

  17. Control Strategies for Smoothing of Output Power of Wind Energy Conversion Systems

    Science.gov (United States)

    Pratap, Alok; Urasaki, Naomitsu; Senju, Tomonobu

    2013-10-01

    This article presents a control method for output power smoothing of a wind energy conversion system (WECS) with a permanent magnet synchronous generator (PMSG) using the inertia of wind turbine and the pitch control. The WECS used in this article adopts an AC-DC-AC converter system. The generator-side converter controls the torque of the PMSG, while the grid-side inverter controls the DC-link and grid voltages. For the generator-side converter, the torque command is determined by using the fuzzy logic. The inputs of the fuzzy logic are the operating point of the rotational speed of the PMSG and the difference between the wind turbine torque and the generator torque. By means of the proposed method, the generator torque is smoothed, and the kinetic energy stored by the inertia of the wind turbine can be utilized to smooth the output power fluctuations of the PMSG. In addition, the wind turbines shaft stress is mitigated compared to a conventional maximum power point tracking control. Effectiveness of the proposed method is verified by the numerical simulations.

  18. Direct Energy Conversion for Low Specific Mass In-Space Power and Propulsion

    Science.gov (United States)

    Scott, John H.; George, Jeffrey A.; Tarditi, Alfonso G.

    2013-01-01

    "Changing the game" in space exploration involves changing the paradigm for the human exploration of the Solar System, e.g, changing the human exploration of Mars from a three-year epic event to an annual expedition. For the purposes of this assessment an "annual expedition" capability is defined as an in-space power & propulsion system which, with launch mass limits as defined in NASA s Mars Architecture 5.0, enables sending a crew to Mars and returning them after a 30-day surface stay within one year, irrespective of planetary alignment. In this work the authors intend to show that obtaining this capability requires the development of an in-space power & propulsion system with an end-to-end specific mass considerably less than 3 kg/kWe. A first order energy balance analysis reveals that the technologies required to create a system with this specific mass include direct energy conversion and nuclear sources that release energy in the form of charged particle beams. This paper lays out this first order approximation and details these conclusions.

  19. Impact of thermal energy storage properties on solar dynamic space power conversion system mass

    Science.gov (United States)

    Juhasz, Albert J.; Coles-Hamilton, Carolyn E.; Lacy, Dovie E.

    1987-01-01

    A 16 parameter solar concentrator/heat receiver mass model is used in conjunction with Stirling and Brayton Power Conversion System (PCS) performance and mass computer codes to determine the effect of thermal energy storage (TES) material property changes on overall PCS mass as a function of steady state electrical power output. Included in the PCS mass model are component masses as a function of thermal power for: concentrator, heat receiver, heat exchangers (source unless integral with heat receiver, heat sink, regenerator), heat engine units with optional parallel redundancy, power conditioning and control (PC and C), PC and C radiator, main radiator, and structure. Critical TES properties are: melting temperature, heat of fusion, density of the liquid phase, and the ratio of solid-to-liquid density. Preliminary results indicate that even though overall system efficiency increases with TES melting temperature up to 1400 K for concentrator surface accuracies of 1 mrad or better, reductions in the overall system mass beyond that achievable with lithium fluoride (LiF) can be accomplished only if the heat of fusion is at least 800 kJ/kg and the liquid density is comparable to that of LiF (1800 kg/cu m).

  20. Maximum power tracking in WECS (Wind energy conversion systems) via numerical and stochastic approaches

    International Nuclear Information System (INIS)

    Elnaggar, M.; Abdel Fattah, H.A.; Elshafei, A.L.

    2014-01-01

    This paper presents a complete design of a two-level control system to capture maximum power in wind energy conversion systems. The upper level of the proposed control system adopts a modified line search optimization algorithm to determine a setpoint for the wind turbine speed. The calculated speed setpoint corresponds to the maximum power point at given operating conditions. The speed setpoint is fed to a generalized predictive controller at the lower level of the control system. A different formulation, that treats the aerodynamic torque as a disturbance, is postulated to derive the control law. The objective is to accurately track the setpoint while keeping the control action free from unacceptably fast or frequent variations. Simulation results based on a realistic model of a 1.5 MW wind turbine confirm the superiority of the proposed control scheme to the conventional ones. - Highlights: • The structure of a MPPT (maximum power point tracking) scheme is presented. • The scheme is divided into the optimization algorithm and the tracking controller. • The optimization algorithm is based on an online line search numerical algorithm. • The tracking controller is treating the aerodynamics torque as a loop disturbance. • The control technique is simulated with stochastic wind speed by Simulink and FAST

  1. Gas Turbine Energy Conversion Systems for Nuclear Power Plants Applicable to LiFTR Liquid Fluoride Thorium Reactor Technology

    Science.gov (United States)

    Juhasz, Albert J.

    2014-01-01

    This panel plans to cover thermal energy and electric power production issues facing our nation and the world over the next decades, with relevant technologies ranging from near term to mid-and far term.Although the main focus will be on ground based plants to provide baseload electric power, energy conversion systems (ECS) for space are also included, with solar- or nuclear energy sources for output power levels ranging tens of Watts to kilo-Watts for unmanned spacecraft, and eventual mega-Watts for lunar outposts and planetary surface colonies. Implications of these technologies on future terrestrial energy systems, combined with advanced fracking, are touched upon.Thorium based reactors, and nuclear fusion along with suitable gas turbine energy conversion systems (ECS) will also be considered by the panelists. The characteristics of the above mentioned ECS will be described, both in terms of their overall energy utilization effectiveness and also with regard to climactic effects due to exhaust emissions.

  2. PREFACE: 14th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2014)

    Science.gov (United States)

    2014-11-01

    It is our great pleasure to welcome you to the 14th International Conference on Micro- and Nano-Technology for Power Generation and Energy Conversion Applications, or PowerMEMS 2014, in Awaji Island, Japan. The aim of PowerMEM is to present the latest research results in the field of miniature, micro- and nano-scale technologies for power generation and energy conversion. The conference will also- give us the opportunity to exchange informations and new ideas in the field of Power MEMS/NEMS. The current status of the field of PowerMEMS spans the full spectrum from basic research to practical applications. We will enjoy valuable discussions not only from the viewpoint of academia but from commercial and industrial perspectives. In the conference, three invited speakers lead the technical program. We received 172 abstracts and after a careful reviewing process by the Technical Program Committee a total of 133 papers were selected for presentation. These have been organized into 16 Oral sessions in two parallel streams and two poster sessions including some late-news papers. The oral and regular poster papers are published by the Institute of Physics (IOP). We have also organized a PowerMEMS School in Kobe-Sannomiya contiguous to the main conference. This two-day school will cover various topics of energy harvesting. World leading experts will give invited lectures on their main topics. This is a new experiment to broaden the technology remit of our conference by organizing mini symposiums that aim to gather the latest research on the following topics by the organizers: Microscale Combustion, Wideband Vibration Energy Harvesting, RF Energy Transfer and Industrial Application. We hope this, and other activities will make PowerMEMS2014 a memorable success. One of the important programs in an international conference is the social program, and we prepare the PowerMEMS2014 banquet in the banquet room at the Westin Awaji Island Hotel. This will provide an opportunity to

  3. Development of methodology for assessment of absorbed dose and stopping power for low energy conversion electrons

    International Nuclear Information System (INIS)

    Almeida, Ivan Pedro Salati de

    1995-08-01

    The evaluation of absorbed dose in the case of external and internal contamination due to radionuclides is sometimes hard, because of the difficulties in the assessment of the absorbed dose caused by electrons with energy less than 100 KeV in mucous membrane. In this work, a methodology for assessment of absorbed dose and stopping power in VYNS (co-polymer of polivinyl chloride - acetate) absorbers, for the 62.5 KeV and 84-88 KeV energy 109 Cd conversion electrons, working with a 4 π proportional pressurized detector, is presented. In order to assure the reproducibility of measurement conditions, one of the detector halves has been used to obtain a spectrum of a thin 109 Cd source, without absorber. The other half of the detector was used in concomitance to obtain spectra with different thicknesses if absorber. The absorbed energy was obtained subtracting each spectrum with absorber from the spectrum without absorber, which were stored in a microcomputer connected to signal processing systems by ACE type interface. The VYNS weight and thickness were evaluated using common radionuclide metrology procedures. As VYNS has characteristics similar to a tissue equivalent material, the results obtained are consistent with dosimetric concepts and have a good agreement with those of the literature. (author)

  4. An Overview of Power, Energy Storage, and Conversion Efforts for 2014 SBIR Phases I and II

    Science.gov (United States)

    Nguyen, Hung D.; Steele, Gynelle C.

    2016-01-01

    Technological innovation is the overall focus of NASA's Small Business Innovation Research (SBIR) program. The program invests in the development of innovative concepts and technologies to help NASA's mission directorates address critical research and development needs for agency projects. NASA's Small Business Innovation Research (SBIR) program focuses on technological innovation by investing in development of innovative concepts and technologies to help NASA mission directorates address critical research needs for Agency programs. This report highlights 15 of the innovative SBIR 2014 Phase I and II projects that focus on one of NASA Glenn Research Center's six core competencies-Power, Energy Storage and Conversion. The technologies cover a wide spectrum of applications such as high-radiation-tolerant ceramic voltage isolators, development of hermetic sealing glasses for solid oxide fuel cells, rechargeable lithium metal cells, high-efficiency direct methane solid oxide fuel cell systems, Li metal protection for high-energy space batteries, isolated bidirectional direct current converters for distributed battery energy applications, and high-efficiency rad-hard ultrathin Si photovoltaic cell technology for space. Each article describes an innovation and technical objective and highlights NASA commercial and industrial applications. This report provides an opportunity for NASA engineers, researchers, and program managers to learn how NASA SBIR technologies could help their programs and projects, and lead to collaborations and partnerships between the small SBIR companies and NASA that would benefit both.

  5. Design and cost of near-term OTEC (Ocean Thermal Energy Conversion) plants for the production of desalinated water and electric power. [Ocean Thermal Energy Conversion (OTEC)

    Energy Technology Data Exchange (ETDEWEB)

    Rabas, T.; Panchal, C.; Genens, L.

    1990-01-01

    There currently is an increasing need for both potable water and power for many islands in the Pacific and Caribbean. The Ocean Thermal Energy Conversion (OTEC) technology fills these needs and is a viable option because of the unlimited supply of ocean thermal energy for the production of both desalinated water and electricity. The OTEC plant design must be flexible to meet the product-mix demands that can be very different from site to site. This paper describes different OTEC plants that can supply various mixes of desalinated water and vapor -- the extremes being either all water and no power or no water and all power. The economics for these plants are also presented. The same flow rates and pipe sizes for both the warm and cold seawater streams are used for different plant designs. The OTEC plant designs are characterized as near-term because no major technical issues need to be resolved or demonstrated. The plant concepts are based on DOE-sponsored experiments dealing with power systems, advanced heat exchanger designs, corrosion and fouling of heat exchange surfaces, and flash evaporation and moisture removal from the vapor using multiple spouts. In addition, the mature multistage flash evaporator technology is incorporated into the plant designs were appropriate. For the supply and discharge warm and cold uncertainties do exist because the required pipe sizes are larger than the maximum currently deployed -- 40-inch high-density polyethylene pipe at Keahole Point in Hawaii. 30 refs., 6 figs., 8 tabs.

  6. Experiments to Improve Power Conversion Parameters in a Traveling Wave Direct Energy Converter Simulator

    International Nuclear Information System (INIS)

    Takeno, Hiromasa; Kiriyama, Yuusuke; Yasaka, Yasuyoshi

    2005-01-01

    An experimental study of direct power conversion for D- 3 He fusion is presented. In a small-scale simulator of direct energy converter, which is based on a principle of deceleration of 14.7MeV protons by traveling wave field, a new structure of an external transmission circuit in experiment is proposed for the purpose of enhancement of deceleration electrode voltages. A prototype circuit was designed and constructed, resulting improvement of voltage amplitude in an order of magnitude. A more practical circuit, in which inductor elements were manufactured by using coaxial cables, was also constructed and tested. An excitation of the third harmonic frequency with a significant amplitude was observed. The cause of this problem is attributed to the modulated ion beam which has a third harmonic component and fact that the inductance of the element nonlinearly depends on frequency. This problem is serious for a practical scale energy converter, and a careful design of the circuit could avoid the problem

  7. Power Control and Optimization of Photovoltaic and Wind Energy Conversion Systems

    Science.gov (United States)

    Ghaffari, Azad

    Power map and Maximum Power Point (MPP) of Photovoltaic (PV) and Wind Energy Conversion Systems (WECS) highly depend on system dynamics and environmental parameters, e.g., solar irradiance, temperature, and wind speed. Power optimization algorithms for PV systems and WECS are collectively known as Maximum Power Point Tracking (MPPT) algorithm. Gradient-based Extremum Seeking (ES), as a non-model-based MPPT algorithm, governs the system to its peak point on the steepest descent curve regardless of changes of the system dynamics and variations of the environmental parameters. Since the power map shape defines the gradient vector, then a close estimate of the power map shape is needed to create user assignable transients in the MPPT algorithm. The Hessian gives a precise estimate of the power map in a neighborhood around the MPP. The estimate of the inverse of the Hessian in combination with the estimate of the gradient vector are the key parts to implement the Newton-based ES algorithm. Hence, we generate an estimate of the Hessian using our proposed perturbation matrix. Also, we introduce a dynamic estimator to calculate the inverse of the Hessian which is an essential part of our algorithm. We present various simulations and experiments on the micro-converter PV systems to verify the validity of our proposed algorithm. The ES scheme can also be used in combination with other control algorithms to achieve desired closed-loop performance. The WECS dynamics is slow which causes even slower response time for the MPPT based on the ES. Hence, we present a control scheme, extended from Field-Oriented Control (FOC), in combination with feedback linearization to reduce the convergence time of the closed-loop system. Furthermore, the nonlinear control prevents magnetic saturation of the stator of the Induction Generator (IG). The proposed control algorithm in combination with the ES guarantees the closed-loop system robustness with respect to high level parameter uncertainty

  8. Energy conversion statics

    CERN Document Server

    Messerle, H K; Declaris, Nicholas

    2013-01-01

    Energy Conversion Statics deals with equilibrium situations and processes linking equilibrium states. A development of the basic theory of energy conversion statics and its applications is presented. In the applications the emphasis is on processes involving electrical energy. The text commences by introducing the general concept of energy with a survey of primary and secondary energy forms, their availability, and use. The second chapter presents the basic laws of energy conversion. Four postulates defining the overall range of applicability of the general theory are set out, demonstrating th

  9. 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.

  10. The 13th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2013)

    Science.gov (United States)

    Mitcheson, Paul; Beeby, Steve

    2013-12-01

    It is a pleasure to welcome you to The Royal Society in London and the 13th International Conference on Micro- and Nano-Technology for Power Generation and Energy Conversion Applications, or PowerMEMS 2013. The objective of PowerMEMS 2013 is to catalyse innovation in miniature, micro- and nano-scale technologies for power generation and energy conversion. The conference aims to stimulate the exchange of insights and information, and the development of new ideas in the Power MEMS/NEMS field as well as at the meso-scale. It will allow the attendees to interact and network within our multidisciplinary community that includes professionals from many branches of science and engineering. The technical program is led by four invited speakers covering inductive power transfer, chip scale power sources, thermal energy harvesting and implantable biofuel cells. We received 177 abstracts and following a careful reviewing process by the Technical Program Committee a total of 137 papers were selected for presentation. These have been organised into 16 oral sessions in two parallel streams and two poster sessions that have been augmented by 10 late news papers. The oral and regular poster papers are, for the first time, being published by the Institute of Physics. We have made every effort to make PowerMEMS 2013 the busiest yet and have included for the first time the PowerMEMS School. This two-day school held at Imperial College London covered a wide range of power-MEMS topics including technologies for power generation, power transmission, energy storage, power electronics interfaces and metrology. Registrations for the School exceeded our expectations and it was full by early November. We hope this, and other activities such as the Discussion Panel and the inclusion of late news papers, will make PowerMEMS 2013 a memorable success. We have also reached out to new communities, such as those working in wireless power transfer and RF harvesting to broaden the technology remit of

  11. Thermodynamics and energy conversion

    CERN Document Server

    Struchtrup, Henning

    2014-01-01

    This textbook gives a thorough treatment of engineering thermodynamics with applications to classical and modern energy conversion devices.   Some emphasis lies on the description of irreversible processes, such as friction, heat transfer and mixing, and the evaluation of the related work losses. Better use of resources requires high efficiencies, therefore the reduction of irreversible losses should be seen as one of the main goals of a thermal engineer. This book provides the necessary tools.   Topics include: car and aircraft engines,  including Otto, Diesel and Atkinson cycles, by-pass turbofan engines, ramjet and scramjet;  steam and gas power plants, including advanced regenerative systems, solar tower, and compressed air energy storage; mixing and separation, including reverse osmosis, osmotic powerplants, and carbon sequestration; phase equilibrium and chemical equilibrium, distillation, chemical reactors, combustion processes, and fuel cells; the microscopic definition of entropy.    The book i...

  12. Solar energy conversion systems

    CERN Document Server

    Brownson, Jeffrey R S

    2013-01-01

    Solar energy conversion requires a different mind-set from traditional energy engineering in order to assess distribution, scales of use, systems design, predictive economic models for fluctuating solar resources, and planning to address transient cycles and social adoption. Solar Energy Conversion Systems examines solar energy conversion as an integrative design process, applying systems thinking methods to a solid knowledge base for creators of solar energy systems. This approach permits different levels of access for the emerging broad audience of scientists, engineers, architects, planners

  13. Environmental effects of energy conversion

    International Nuclear Information System (INIS)

    Hansmeyer, K.H.; Fortak, H.; Knoepp, H.; Lindackers, K.H.; Schafhausen, F.; Schoedel, J.P.

    1984-01-01

    The article presents an analysis of energy conversion systems by the ''Council of Environmental Experts'' in order to correct the erroneous assumption that small energy conversion systems will also be small-scale and negligible emitters of pollutants. The additional pollution caused by Neurath power plant is considered to be low, at least in its immediate vicinity, owing to the implementation of the most recent technical developments. The environmental effects of energy conversion processes are discussed, including the waste heat problem and processes for water-cooling of power plants. General aspects of a new concept of energy taxation are discussed which is to reduce energy consumption. The problem of radioactive waste is discussed from spent fuel storage and reprocessing to the decommissioning of older power plants. The author points out that also new fossil-fuel technologies will pollute the environment. (orig.) [de

  14. Physical basis of power conversion of energy fluctuations of hot electrons

    Energy Technology Data Exchange (ETDEWEB)

    Yater, J C

    1983-12-01

    The design of an experimental reversible-energy-fluctuation (REF) solar converter using hot nonequilibrated (HNE) electrons is presented. The physical principles are introduced, and an idealized model is described and analyzed in terms of radiation and electron-thermalization losses and first-to-third-layer transfer times. It is shown that the 93-percent limiting conversion efficiency can be approached in both a two-level and an N-level model, even in larger-scale circuits. On the other hand, as circuit size is decreased below 100 nm, the maximum power output can exceed 10 MW/sq m. The materials and thicknesses to be used in an experimental thin-film version of the REF device are outlined, including a 10-60-nm-thick Cd3As2 or alpha-Sn absorbing layer, a 4-10-nm-thick doped-semiconductor or semimetal quantum-well layer, and a Schottky-barrier diode layer comprising a 4-10-nm-thick Pb sheet on a 5-20-nm-thick p-GaAs film. Experiments at lattice temperatures of from 300 to 1 K with input radiation at wavelengths from 1 micron to the solar spectrum and intensities from zero to 1 mW are planned to determine whether the predicted practical efficiency of 80 percent can be obtained. 19 references.

  15. Direct conversion of fusion energy

    International Nuclear Information System (INIS)

    Johansson, Markus

    2003-03-01

    Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D- 3 He reaction and the p- 11 B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger βB 2 0 to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high β values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D- 3 He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D 3 He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D 3 He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion or liquid metal MHD conversion (LMMHD). For a D

  16. Direct conversion of fusion energy

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Markus

    2003-03-01

    Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D-{sup 3}He reaction and the p-{sup 11}B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger {beta}B{sup 2}{sub 0} to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high {beta} values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D-{sup 3}He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D{sub 3} He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D{sub 3} He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion

  17. 16th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2016)

    International Nuclear Information System (INIS)

    2016-01-01

    It is our great pleasure to welcome you to PowerMEMS’16 - the 16th International Conference on Micro- and Nano-Technology for Power Generation and Energy Conversion Applications - in Paris at the UIC Espace Congrès, a few meters away from the Eiffel Tower. The objective of the PowerMEMS conference is to catalyse innovation in micro- and nano- scale technologies for the energy domain. The scope of the meeting ranges from basic principles, to materials and fabrication, to devices and systems, to applications. The many applications of Power MEMS concern the harvesting, storage, conversion and conditioning of energy, to integrated systems that manage these processes, to actuation, pumping, and propulsion. Our Conference aims to stimulate the exchange of insights and information, as well as the development of new ideas, in the Power MEMS field. Our goal is to allow the attendees to interact and network within our multidisciplinary community that includes professionals from many branches of science and engineering, as well as energy, policy, and entrepreneurial specialists interested in the commercialization of Power MEMS technologies. This year's technical program is highlighted by four plenary talks from prominent experts on M/NEMS for ultra-low power in electronics, advanced nanomaterial for solar cells and thermal transistor. The contributed program received 159 abstract submissions this year. After careful review by the 33-members of the Technical Program Committee, a total of 123 papers will be presented. The 40 contributed oral presentations are arranged in two parallel sessions. The 83 posters are arranged in a ''two-in-one'' poster session in which the poster session time is divided in two; half the posters will be presented during each half-session, allowing the poster presenters to also browse the posters during the poster session. Posters will remain up during the meeting, so please feel free to peruse them at your leisure. The

  18. Power conversion technologies

    Energy Technology Data Exchange (ETDEWEB)

    Newton, M. A.

    1997-02-01

    The Power Conversion Technologies thrust area identifies and sponsors development activities that enhance the capabilities of engineering at Lawrence Livermore National Laboratory (LLNL) in the area of solid- state power electronics. Our primary objective is to be a resource to existing and emerging LLNL programs that require advanced solid-state power electronic technologies.. Our focus is on developing and integrating technologies that will significantly impact the capability, size, cost, and reliability of future power electronic systems. During FY-96, we concentrated our research efforts on the areas of (1) Micropower Impulse Radar (MIR); (2) novel solid-state opening switches; (3) advanced modulator technology for accelerators; (4) compact accelerators; and (5) compact pulse generators.

  19. Corrosion and biofouling on the non-heat-exchanger surfaces of an ocean thermal energy conversion power plant: a survey

    Energy Technology Data Exchange (ETDEWEB)

    Castelli, V.J. (ed.)

    1979-05-01

    Of the many foreseeable problems confronting economical ocean thermal energy conversion operation, two major items are the deterioration of the structural and functional components, which prevents efficient operation, and the biofouling of the surfaces, which adds excess weight to the floating ocean platform. The techniques required for effective long-term control of deterioration and corrosion have been investigated actively for many years, and successful solutions for most situations have been developed. For the most part, these solutions can be directly transferred to the ocean thermal energy conversion plant. The majority of problems in these areas are expected to be associated with scale-up and will require some advanced development due to the immensity of the ocean thermal energy conversion platform. Current antifouling control systems are not effective for long-term fouling prevention. Commercially available antifouling coatings are limited to a 3-year service life in temperate waters, and even shorter in tropical waters. However, underwater cleaning techniques and some fouling-control systems presently being used by conventional power plants may find utility on an ocean thermal energy conversion plant. In addition, some recent major advances in long-term antifouling coatings sponsored by the Navy may be applicable to ocean thermal energy conversion. 132 references.

  20. Autonomous renewable energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Valtchev, V. [Technical University of Varna (Bulgaria). Dept. of Electronics; Bossche, A. van den; Ghijselen, J.; Melkebeek, J. [University of Gent (Belgium). Dept. of Electrical Power Engineering

    2000-02-01

    This paper briefly reviews the need for renewable power generation and describes a medium-power Autonomous Renewable Energy Conversion System (ARECS), integrating conversion of wind and solar energy sources. The objectives of the paper are to extract maximum power from the proposed wind energy conversion scheme and to transfer this power and the power derived by the photovoltaic system in a high efficiency way to a local isolated load. The wind energy conversion operates at variable shaft speed yielding an improved annual energy production over constant speed systems. An induction generator (IG) has been used because of its reduced cost, robustness, absence of separate DC source for excitation, easier dismounting and maintenance. The maximum energy transfer of the wind energy is assured by a simple and reliable control strategy adjusting the stator frequency of the IG so that the power drawn is equal to the peak power production of the wind turbine at any wind speed. The presented control strategy also provides an optimal efficiency operation of the IG by applying a quadratic dependence between the IG terminal voltage and frequency V {approx} f{sup 2}. For improving the total system efficiency, high efficiency converters have been designed and implemented. The modular principle of the proposed DC/DC conversion provides the possibility for modifying the system structure depending on different conditions. The configuration of the presented ARECS and the implementation of the proposed control algorithm for optimal power transfer are fully discussed. The stability and dynamic performance as well as the different operation modes of the proposed control and the operation of the converters are illustrated and verified on an experimental prototype. (author)

  1. Thermionic energy conversion heat - electric power; Termojonisk energiomvandling vaerme-elektrisk energi

    Energy Technology Data Exchange (ETDEWEB)

    Holmlid, L; Svensson, R [Gothenburg Univ. and Chalmers Univ. of Technology (Sweden)

    1993-09-15

    Research and development related to Thermionic Energy Converters (TEC) in Holland and Sweden is directed towards terrestrial applications, while the development work in Russia and the US primarily is directed towards thermionic nuclear reactor for use in space. We have during the project continued our work on the utilization of the so called Rydberg matter in converters. Our patented construction has very good (low) values of the barrier index (figure of merit for the converter), probably the lowest ones ever measured. International patents have been applied for as well. We can summarize the achievements of the project such that solutions to practically all the problems related to the inner function of thermionic converters have been found. During this year a large number of studies have been carried out concerning the properties of the Rydberg matter in the TEC, and related to the highly excited states of Cs which exist in the TEC, partially in cooperation with an American research company. An international conference within the TEC field has been arranged in Gothenburg. Two Ph.D. theses are also under completion within the project

  2. Steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Fang, Jiakun; Li, Jinghua

    2016-01-01

    Nowadays, the electric power system and natural gas network are becoming increasingly coupled and interdependent. A harmonized integration of natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables in terms of system...... flexibility. This work focuses on the steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion. A unified energy flow formulation is developed to describe the nodal balance and branch flow in both systems and it is solved with the Newton......–Raphson method. Both the unification of units and the per-unit system are proposed to simplify the system description and to enhance the computation efficiency. The applicability of the proposed method is demonstrated by analyzing an IEEE-9 test system integrated with a 7-node natural gas network. Later, time...

  3. Space satellite power system. [conversion of solar energy by photovoltaic solar cell arrays

    Science.gov (United States)

    Glaser, P. E.

    1974-01-01

    The concept of a satellite solar power station was studied. It is shown that it offers the potential to meet a significant portion of future energy needs, is pollution free, and is sparing of irreplaceable earth resources. Solar energy is converted by photovoltaic solar cell arrays to dc energy which in turn is converted into microwave energy in a large active phased array. The microwave energy is beamed to earth with little attenuation and is converted back to dc energy on the earth. Economic factors are considered.

  4. L1 Adaptive Speed Control of a Small Wind Energy Conversion System for Maximum Power Point Tracking

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Rasmussen, Claus Nygaard

    2014-01-01

    This paper presents the design of an L1 adaptive controller for maximum power point tracking (MPPT) of a small variable speed Wind Energy Conversion System (WECS). The proposed controller generates the optimal torque command for the vector controlled generator side converter (GSC) based on the wi......) is used to carry out case studies using Matlab/Simulink. The case study results show that the designed L1 adaptive controller has good tracking performance even with unmodeled dynamics and in the presence of parameter uncertainties and unknown disturbances.......This paper presents the design of an L1 adaptive controller for maximum power point tracking (MPPT) of a small variable speed Wind Energy Conversion System (WECS). The proposed controller generates the optimal torque command for the vector controlled generator side converter (GSC) based on the wind...

  5. EDITORIAL: The 6th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion Applications (PowerMEMS 2006)

    Science.gov (United States)

    Fréchette, Luc G.

    2007-09-01

    Energy is a sector of paramount importance over the coming decades if we are to ensure sustainable development that respects our environment. The research and development of novel approaches to convert available energy into usable forms using micro and nanotechnologies can contribute towards this goal and meet the growing need for power in small scale portable applications. The dominant power sources for handheld and other portable electronics are currently primary and rechargeable batteries. Their limited energy density and adverse effects on the environment upon disposal suggest that alternative approaches need to be explored. This special issue will showcase some of the leading work in this area, initially presented at PowerMEMS 2006, the 6th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion Applications. Power MEMS are defined as microsystems for electrical power generation and other energy conversion applications, including propulsion and cooling. The range of power MEMS technologies includes micro thermodynamic machines, such as microturbines, miniature internal combustion engines and micro-coolers; solid-state direct energy conversion, such as thermoelectric and photovoltaic microstructures; micro electrochemical devices, such as micro fuel cells and nanostructure batteries; vibration energy harvesting devices, such as piezoelectric, magnetic or electrostatic micro generators, as well as micro thrusters and rocket engines for propulsion. These can either be driven by scavenging thermal, mechanical or solar energy from the environment, or from a stored energy source, such as chemical fuel or radioactive material. The unique scope leads to unique challenges in the development of power MEMS, ranging from the integration of novel materials to the efficient small scale implementation of energy conversion principles. In this special issue, Mitcheson et al provide a comparative assessment of three inertial vibration

  6. Power Plant with C02 -Capture and Solar Energy Conversion in Microalgae Mass Culture

    International Nuclear Information System (INIS)

    Borodyanski, G.; Yantovski, E.; Levin, L.

    1998-01-01

    The purpose of the present study was to investigate a concept of a fuel reproduction after its burning and C02 trapping. This concept is considered with practical (technical) point of view. We focus our attention on the involving of biological system of fuel reproduction and C02 trapping in power plant for electricity production. The paper discusses the energy, biological, ecological and economical aspects of such power plant. This work is connected with potential development of zero-emission power and technological plant on the base of microalgae solar

  7. Ocean thermal energy conversion (OTEC). Power system development. Preliminary design report, final

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    The preliminary design of the 10 MWe OTEC power module and the 200 kWe test articles is given in detail. System operation and performance; power system cost estimates; 10 MWe heat exchangers; 200 kWe heat exchanger articles; biofouling control;ammonia leak detection, and leak repair; rotating machinery; support subsystem; instrumentation and control; electrical subsystem; installation approach; net energy and resource analysis; and operability, maintainability, and safety are discussed. The conceptual design of the 40 MWe electrical power system includes four or five 10 MWe modules as designed for the 10 MWe pilot plant. (WHK)

  8. Photovoltaic solar energy conversion

    CERN Document Server

    Bauer, Gottfried H

    2015-01-01

    This concise primer on photovoltaic solar energy conversion invites readers to reflect on the conversion of solar light into energy at the most fundamental level and encourages newcomers to the field to help find meaningful answers on how photovoltaic solar energy conversion can work (better), eventually contributing to its ongoing advancement. The book is based on lectures given to graduate students in the Physics Department at the University of Oldenburg over the last two decades, yet also provides an easy-to-follow introduction for doctoral and postdoctoral students from related disciplines such as the materials sciences and electrical engineering. Inspired by classic textbooks in the field, it reflects the author’s own ideas on how to understand, visualize and eventually teach the microscopic physical mechanisms and effects, while keeping the text as concise as possible so as to introduce interested readers to the field and balancing essential knowledge with open questions.

  9. Renewable Energy Supply for Power Dominated, Energy Intense Production Processes - A Systematic Conversion Approach for the Anodizing Process

    Science.gov (United States)

    >D Stollenwerk, T Kuvarakul, I Kuperjans,

    2013-06-01

    European countries are highly dependent on energy imports. To lower this import dependency effectively, renewable energies will take a major role in future energy supply systems. To assist the national and inter-European efforts, extensive changes towards a renewable energy supply, especially on the company level, will be unavoidable. To conduct this conversion in the most effective way, the methodology developed in this paper can support the planning procedure. It is applied to the energy intense anodizing production process, where the electrical demand is the governing factor for the energy system layout. The differences between the classical system layout based on the current energy procurement and an approach with a detailed load-time-curve analysis, using process decomposition besides thermodynamic optimization, are discussed. The technical effects on the resulting energy systems are shown besides the resulting energy supply costs which will be determined by hourly discrete simulation.

  10. Renewable Energy Supply for Power Dominated, Energy Intense Production Processes – A Systematic Conversion Approach for the Anodizing Process

    International Nuclear Information System (INIS)

    Stollenwerk, D; Kuvarakul, T; Kuperjans, I

    2013-01-01

    European countries are highly dependent on energy imports. To lower this import dependency effectively, renewable energies will take a major role in future energy supply systems. To assist the national and inter-European efforts, extensive changes towards a renewable energy supply, especially on the company level, will be unavoidable. To conduct this conversion in the most effective way, the methodology developed in this paper can support the planning procedure. It is applied to the energy intense anodizing production process, where the electrical demand is the governing factor for the energy system layout. The differences between the classical system layout based on the current energy procurement and an approach with a detailed load-time-curve analysis, using process decomposition besides thermodynamic optimization, are discussed. The technical effects on the resulting energy systems are shown besides the resulting energy supply costs which will be determined by hourly discrete simulation.

  11. Ocean wave energy conversion

    CERN Document Server

    McCormick, Michael E

    2007-01-01

    This volume will prove of vital interest to those studying the use of renewable resources. Scientists, engineers, and inventors will find it a valuable review of ocean wave mechanics as well as an introduction to wave energy conversion. It presents physical and mathematical descriptions of the nine generic wave energy conversion techniques, along with their uses and performance characteristics.Author Michael E. McCormick is the Corbin A. McNeill Professor of Naval Engineering at the U.S. Naval Academy. In addition to his timely and significant coverage of possible environmental effects associa

  12. Magnetohydrodynamic energy conversion

    International Nuclear Information System (INIS)

    Rosa, R.J.

    1987-01-01

    The object of this book is to present a review of the basic principles and practical aspects of magnetohydrodynamic (MHD) energy conversion. The author has tried to give qualitative semiphysical arguments where possible for the benefit of the reader who is unfamiliar with plasma physics. The aim of MHD energy conversion is to apply to a specific practical goal a part of what has become a vast area of science called plasma physics. The author has attempted to note in the text where a broader view might be fruitful and to give appropriate references

  13. High power densities from high-temperature material interactions. [in thermionic energy conversion and metallic fluid heat pipes

    Science.gov (United States)

    Morris, J. F.

    1981-01-01

    Thermionic energy conversion (TEC) and metallic-fluid heat pipes (MFHPs), offering unique advantages in terrestrial and space energy processing by virtue of operating on working-fluid vaporization/condensation cycles that accept great thermal power densities at high temperatures, share complex materials problems. Simplified equations are presented that verify and solve such problems, suggesting the possibility of cost-effective applications in the near term for TEC and MFHP devices. Among the problems discussed are: the limitation of alkali-metal corrosion, protection against hot external gases, external and internal vaporization, interfacial reactions and diffusion, expansion coefficient matching, and creep deformation.

  14. Optimization theory for ballistic energy conversion

    NARCIS (Netherlands)

    Xie, Yanbo; Versluis, Michel; Van Den Berg, Albert; Eijkel, Jan C.T.

    2016-01-01

    The growing demand of renewable energy stimulates the exploration of new materials and methods for clean energy. We recently demonstrated a high efficiency and power density energy conversion mechanism by using jetted charged microdroplets, termed as ballistic energy conversion. Hereby, we model and

  15. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 1: Introduction and summary and general assumptions. [energy conversion systems for electric power plants using coal - feasibility

    Science.gov (United States)

    Beecher, D. T.

    1976-01-01

    Nine advanced energy conversion concepts using coal or coal-derived fuels are summarized. They are; (1) open-cycle gas turbines, (2) combined gas-steam turbine cycles, (3) closed-cycle gas turbines, (4) metal vapor Rankine topping, (5) open-cycle MHD; (6) closed-cycle MHD; (7) liquid-metal MHD; (8) advanced steam; and (9) fuel cell systems. The economics, natural resource requirements, and performance criteria for the nine concepts are discussed.

  16. A Direct Power Conversion Topology for Grid Integration of Hybrid AC/DC Energy Resources

    DEFF Research Database (Denmark)

    Liu, Xiong; Loh, Poh Chiang; Wang, Peng

    2013-01-01

    This paper proposes a multiple-input versatile matrix converter (VMC) for integrating hybrid ac/dc energy resources and storages to the power grid. The VMC is developed from the traditional indirect matrix converter but operates in the reverse-boost mode rather than in the forward-buck mode....... The reverse-boost mode is more relevant here since most renewable sources and energy storages have lower voltages than the grid. The eventual VMC developed uses an alternative nine-switch converter, rather than usual six-switch voltage-source converter, for providing six input terminals in total. One three...

  17. Solar microclimatology. [tables (data) on insolation for application to solar energy conversion by electric power plants

    Science.gov (United States)

    Mckenney, D. B.; Beauchamp, W. T.

    1975-01-01

    It has become apparent in recent years that solar energy can be used for electric power production by several methods. Because of the diffuse nature of the solar insolation, the area involved in any central power plant design can encompass several square miles. A detailed design of these large area collection systems will require precise knowledge of the local solar insolation. Detailed information will also be needed concerning the temporal nature of the insolation and the local spatial distribution. Therefore, insolation data was collected and analyzed for a network of sensors distributed over an area of several square kilometers in Arizona. The analyses of this data yielded probability distributions of cloud size, velocity, and direction of motion which were compared with data obtained from the National Weather Service. Microclimatological analyses were also performed for suitable modeling parameters pertinent to large scale electric power plant design. Instrumentation used to collect the data is described.

  18. Energy Conversion and Storage Program

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, E.J.

    1992-03-01

    The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes, and (5) application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Topics include identification of new electrochemical couples for advanced rechargeable batteries, improvements in battery and fuel-cell materials, and the establishment of engineering principles applicable to electrochemical energy storage and conversion. Chemical Applications research includes topics such as separations, catalysis, fuels, and chemical analyses. Included in this program area are projects to develop improved, energy-efficient methods for processing waste streams from synfuel plants and coal gasifiers. Other research projects seek to identify and characterize the constituents of liquid fuel-system streams and to devise energy-efficient means for their separation. Materials Applications research includes the evaluation of the properties of advanced materials, as well as the development of novel preparation techniques. For example, the use of advanced techniques, such as sputtering and laser ablation, are being used to produce high-temperature superconducting films.

  19. Microbial Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, Merry [American Society for Microbiology (ASM), Washington, DC (United States); Wall, Judy D. [Univ. of Missouri, Columbia, MO (United States)

    2006-10-01

    The American Academy of Microbiology convened a colloquium March 10-12, 2006, in San Francisco, California, to discuss the production of energy fuels by microbial conversions. The status of research into various microbial energy technologies, the advantages and disadvantages of each of these approaches, research needs in the field, and education and training issues were examined, with the goal of identifying routes for producing biofuels that would both decrease the need for fossil fuels and reduce greenhouse gas emissions. Currently, the choices for providing energy are limited. Policy makers and the research community must begin to pursue a broader array of potential energy technologies. A diverse energy portfolio that includes an assortment of microbial energy choices will allow communities and consumers to select the best energy solution for their own particular needs. Funding agencies and governments alike need to prepare for future energy needs by investing both in the microbial energy technologies that work today and in the untested technologies that will serve the world’s needs tomorrow. More mature bioprocesses, such as ethanol production from starchy materials and methane from waste digestors, will find applications in the short term. However, innovative techniques for liquid fuel or biohydrogen production are among the longer term possibilities that should also be vigorously explored, starting now. Microorganisms can help meet human energy needs in any of a number of ways. In their most obvious role in energy conversion, microorganisms can generate fuels, including ethanol, hydrogen, methane, lipids, and butanol, which can be burned to produce energy. Alternatively, bacteria can be put to use in microbial fuel cells, where they carry out the direct conversion of biomass into electricity. Microorganisms may also be used some day to make oil and natural gas technologies more efficient by sequestering carbon or by assisting in the recovery of oil and

  20. Complete biocycle for solar energy conversion, storage, fuel and power generation, and coal conservation for future use

    International Nuclear Information System (INIS)

    Srivastava, S.C.

    1993-01-01

    A complete carbon biocycle has been described, starting from coal in in situ condition in coal seams underground. Various steps involved are: (i) Biogasification of coal to methane, using a consortia of bacteria, has been reported. A group of bacteria degrades complex structure of coal to simpler structure. This simpler structure of coal, is then converted to methane by methanogens; (ii) Biophotolysis of methane and associated biodegradation, results in products, such as hydrogen and oxygen for use in fuel cells for power generation; (iii) Bioconversion of products so obtained is carried out to produce methanol or methane that could be used as fuel or recycled; (iv) In complete biocycle some methane is converted to biomass. In order to replace this methane, coal is converted to methane using group of bacteria, only to the extent methane has been converted to biomass; (v) The biomass so produced could be dumped underground from where coal has been gasified. Alternatively it could be burnt as fuel or else used as substitute of protein in animal food. Detailed concept of proposed technology for: (a) an alternative to conventional coal mining, (b) generation of power using products of bioconversion in fuel cell, and (c) conversation of solar energy for generation of alternative source of fuel and power, has been discussed. Possibility of developing a biofuel cell for conversion of solar energy through bioelectrochemical route has been suggested. (author). 48 refs., 3 figs

  1. Solar energy conversion

    CERN Document Server

    Likhtenshtein, Gertz I

    2012-01-01

    Finally filling a gap in the literature for a text that also adopts the chemist?s view of this hot topic, Prof Likhtenshtein, an experienced author and internationally renowned scientist, considers different physical and engineering aspects in solar energy conversion. From theory to real-life systems, he shows exactly which chemical reactions take place when converting light energy, providing an overview of the chemical perspective from fundamentals to molecular harvesting systems and solar cells. This essential guide will thus help researchers in academia and industry better understa

  2. Principles of energy conversion, second edition

    International Nuclear Information System (INIS)

    Culp, A.W. Jr.

    1991-01-01

    This book is organized under the following headings: Energy classification, sources, utilization, economics and terminology; Principal fuels for energy conversion; Production of thermal energy; Fossil-fuel systems (such as steam generators, etc.); Nuclear reactor design and operation; The environmental impact of power plant operation; Production of mechanical energy; Production of electrical energy; and Energy storage

  3. Energy Harvesting for Self-Powered, Ultra-Low Power Microsystems With a Focus on Vibration-Based Electromechanical Conversion

    Science.gov (United States)

    2009-09-01

    capacitor responsible for charge. Figure 25. Half Bridge Power Harvester with Leakage Resistance [From 70] The resistor accounts for the voltage...REV PAP, 1996. [63] M. Umeda, K. Nakamura, and S. Ueha, “Energy storage characteristics of a piezo - generator using impact induced vibration...Japanese journal of applied physics, vol. 36, pp. 3146–3151, 1997. [64] M. Kimura, “ Piezo -electricity generation device,” U.S. Patent 812070, September

  4. Neural Network Based Maximum Power Point Tracking Control with Quadratic Boost Converter for PMSG—Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Ramji Tiwari

    2018-02-01

    Full Text Available This paper proposes an artificial neural network (ANN based maximum power point tracking (MPPT control strategy for wind energy conversion system (WECS implemented with a DC/DC converter. The proposed topology utilizes a radial basis function network (RBFN based neural network control strategy to extract the maximum available power from the wind velocity. The results are compared with a classical Perturb and Observe (P&O method and Back propagation network (BPN method. In order to achieve a high voltage rating, the system is implemented with a quadratic boost converter and the performance of the converter is validated with a boost and single ended primary inductance converter (SEPIC. The performance of the MPPT technique along with a DC/DC converter is demonstrated using MATLAB/Simulink.

  5. Power energy. Systems for energy conversion. Compact knowledge for study and profession. 5. rev. and enl. ed.; Energietechnik. Systeme zur Energieumwandlung. Kompaktwissen fuer Studium und Beruf

    Energy Technology Data Exchange (ETDEWEB)

    Zahoransky, Richard A. (ed.); Allelein, Hans-Josef; Bollin, Elmar; Oehler, Helmut; Schelling, Udo

    2010-07-01

    This textbook imparts to the reader a fundamental understanding for relations of energy conversion processes. It comprises the total spectra of energy engineering, starting with fundamentals of energy process engineering via description of operating power plants (all types) to energy distribution and - storage. Main topics are sustainable energy systems from renewable energy sources. combined systems (e.g. Gas/steam turbine power plants) and plants with cogeneration (e.g. modular cogeneration plants). A new chapter Kyoto-Protocol was created as a concept of emissions-free coal-fired power plants. A new wording for deregulation of energy markets was received. Numerous texts and graphs were been revised. Chapter 18 ''Deregulation of Energy Markets'' is newly revised. The 5th edition was actualized by new trends in energy engineering, chapter wind energy revised, and deregulation topics in the energy market extended. Due to its didactic concepts the book directs not only to students but also everybody, who is inerested into actual questions of energy engineering. (orig./GL)

  6. Power Quality Control and Design of Power Converter for Variable-Speed Wind Energy Conversion System with Permanent-Magnet Synchronous Generator

    Directory of Open Access Journals (Sweden)

    Yüksel Oğuz

    2013-01-01

    Full Text Available The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%.

  7. Power quality control and design of power converter for variable-speed wind energy conversion system with permanent-magnet synchronous generator.

    Science.gov (United States)

    Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin

    2013-01-01

    The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%.

  8. Flow energy conversion system

    International Nuclear Information System (INIS)

    Sargsyan, R.A.

    2011-01-01

    A cost-effective hydropower system called here Flow Energy Converter was developed, patented, manufactured and tested for water pumping, electricity generation and other purposes especially useful for the rural communities. The system consists of water-driven turbine with plane-surface blades, power transmission means and pump and/or generator. Working sample of the Flow Energy Converter was designed and manufactured at the Institute of Radio Physics and Electronics

  9. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 11: Advanced steam systems. [energy conversion efficiency for electric power plants using steam

    Science.gov (United States)

    Wolfe, R. W.

    1976-01-01

    A parametric analysis was made of three types of advanced steam power plants that use coal in order to have a comparison of the cost of electricity produced by them a wide range of primary performance variables. Increasing the temperature and pressure of the steam above current industry levels resulted in increased energy costs because the cost of capital increased more than the fuel cost decreased. While the three plant types produced comparable energy cost levels, the pressurized fluidized bed boiler plant produced the lowest energy cost by the small margin of 0.69 mills/MJ (2.5 mills/kWh). It is recommended that this plant be designed in greater detail to determine its cost and performance more accurately than was possible in a broad parametric study and to ascertain problem areas which will require development effort. Also considered are pollution control measures such as scrubbers and separates for particulate emissions from stack gases.

  10. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 12: Fuel cells. [energy conversion efficiency of, for use in electric power plants

    Science.gov (United States)

    Warde, C. J.; Ruka, R. J.; Isenberg, A. O.

    1976-01-01

    A parametric assessment of four fuel cell power systems -- based on phosphoric acid, potassium hydroxide, molten carbonate, and stabilized zirconia -- has shown that the most important parameters for electricity-cost reduction and/or efficiency improvement standpoints are fuel cell useful life and power density, use of a waste-heat recovery system, and fuel type. Typical capital costs, overall energy efficiencies (based on the heating value of the coal used to produce the power plant fuel), and electricity costs are: phosphoric acid $350-450/kWe, 24-29%, and 11.7 to 13.9 mills/MJ (42 to 50 mills/kWh); alkaline $450-700/kWe, 26-31%, and 12.8 to 16.9 mills/MJ (46 to 61 mills/kWh); molten carbonate $480-650/kWe, 32-46%, and 10.6 to 19.4 mills/MJ (38 to 70 mills/kWh), stabilized zirconia $420-950/kWe, 26-53%, and 9.7 to 16.9 mills/MJ (35 to 61 mills/kWh). Three types of fuel cell power plants -- solid electrolytic with steam bottoming, molten carbonate with steam bottoming, and solid electrolyte with an integrated coal gasifier -- are recommended for further study.

  11. Ocean thermal energy conversion power system development-I. Phase I. Preliminary design report. Volume 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-18

    The results of a conceptual and preliminary design study of Ocean Thermal Energy Conversion (OTEC) closed loop ammonia power system modules performed by Lockheed Missiles and Space Company, Inc. (LMSC) are presented. This design study is the second of 3 tasks in Phase I of the Power System Development-I Project. The Task 2 objectives were to develop: 1) conceptual designs for a 40 to 50-MW(e) closed cycle ammonia commercial plant size power module whose heat exchangers are immersed in seawater and whose ancillary equipments are in a shirt sleeve environment; preliminary designs for a modular application power system sized at 10-MW(e) whose design, construction and material selection is analogous to the 50 MW(e) module, except that titanium tubes are to be used in the heat exchangers; and 3) preliminary designs for heat exchanger test articles (evaporator and condenser) representative of the 50-MW(e) heat exchangers using aluminum alloy, suitable for seawater service, for testing on OTEC-1. The reference ocean platform was specified by DOE as a surface vessel with the heat exchanger immersed in seawater to a design depth of 0 to 20 ft measured from the top of the heat exchanger. For the 50-MW(e) module, the OTEC 400-MW(e) Plant Ship, defined in the Platform Configuration and Integration study, was used as the reference platform. System design, performance, and cost are presented. (WHK)

  12. Error Assessment of Solar Irradiance Forecasts and AC Power from Energy Conversion Model in Grid-Connected Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Gianfranco Chicco

    2015-12-01

    Full Text Available Availability of effective estimation of the power profiles of photovoltaic systems is essential for studying how to increase the share of intermittent renewable sources in the electricity mix of many countries. For this purpose, weather forecasts, together with historical data of the meteorological quantities, provide fundamental information. The weak point of the forecasts depends on variable sky conditions, when the clouds successively cover and uncover the solar disc. This causes remarkable positive and negative variations in the irradiance pattern measured at the photovoltaic (PV site location. This paper starts from 1 to 3 days-ahead solar irradiance forecasts available during one year, with a few points for each day. These forecasts are interpolated to obtain more irradiance estimations per day. The estimated irradiance data are used to classify the sky conditions into clear, variable or cloudy. The results are compared with the outcomes of the same classification carried out with the irradiance measured in meteorological stations at two real PV sites. The occurrence of irradiance spikes in “broken cloud” conditions is identified and discussed. From the measured irradiance, the Alternating Current (AC power injected into the grid at two PV sites is estimated by using a PV energy conversion model. The AC power errors resulting from the PV model with respect to on-site AC power measurements are shown and discussed.

  13. Implementation of a new maximum power point tracking control strategy for small wind energy conversion systems without mechanical sensors

    International Nuclear Information System (INIS)

    Daili, Yacine; Gaubert, Jean-Paul; Rahmani, Lazhar

    2015-01-01

    Highlights: • A new maximum power point tracking algorithm for small wind turbines is proposed. • This algorithm resolves the problems of the classical perturb and observe method. • The proposed method has been tested under several wind speed profiles. • The validity of the new algorithm has been confirmed by the experimental results. - Abstract: This paper proposes a modified perturbation and observation maximum power point tracking algorithm for small wind energy conversion systems to overcome the problems of the conventional perturbation and observation technique, namely rapidity/efficiency trade-off and the divergence from peak power under a fast variation of the wind speed. Two modes of operation are used by this algorithm, the normal perturbation and observation mode and the predictive mode. The normal perturbation and observation mode with small step-size is switched under a slow wind speed variation to track the true maximum power point with fewer fluctuations in steady state. When a rapid change of wind speed is detected, the algorithm tracks the new maximum power point in two phases: in the first stage, the algorithm switches to the predictive mode in which the step-size is auto-adjusted according to the distance between the operating point and the estimated optimum point to move the operating point near to the maximum power point rapidly, and then the normal perturbation and observation mode is used to track the true peak power in the second stage. The dc-link voltage variation is used to detect rapid wind changes. The proposed algorithm does not require either knowledge of system parameters or of mechanical sensors. The experimental results confirm that the proposed algorithm has a better performance in terms of dynamic response and efficiency compared with the conventional perturbation and observation algorithm

  14. Compact Energy Conversion Module, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This STTR project delivers a compact vibration-based Energy Conversion Module (ECM) that powers sensors for purposes such as structural health monitoring (SHM). NASA...

  15. Compact energy conversion module, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This STTR project delivers a compact vibration-based Energy Conversion Module (ECM) that powers sensors for purposes like structural health monitoring (SHM). NASA...

  16. NASA-OAST photovoltaic energy conversion program

    Science.gov (United States)

    Mullin, J. P.; Loria, J. C.

    1984-01-01

    The NASA program in photovoltaic energy conversion research is discussed. Solar cells, solar arrays, gallium arsenides, space station and spacecraft power supplies, and state of the art devices are discussed.

  17. PREFACE: The 15th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2015)

    Science.gov (United States)

    Livermore, C.; Velásquez-García, L. F.

    2015-12-01

    Greetings, and welcome to Boston, MA and PowerMEMS 2015 - the 15th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications! The objective of PowerMEMS 2015 is to catalyze innovation in micro- and nano-scale technologies for the energy domain. The scope of the meeting ranges from basic principles, to materials and fabrication, to devices and systems, to applications. The many applications of Power MEMS range from the harvesting, storage, conversion and conditioning of energy, to integrated systems that manage these processes, to actuation, pumping, and propulsion. Our Conference aims to stimulate the exchange of insights and information, as well as the development of new ideas, in the Power MEMS field. Our goal is to allow the attendees to interact and network within our multidisciplinary community that includes professionals from many branches of science and engineering, as well as energy, policy, and entrepreneurial specialists interested in the commercialization of Power MEMS technologies. Since the first PowerMEMS in Sendai, Japan in 2000, the Conference has grown in size, reputation, impact, and technical breadth. This continuing growth is evident in this year's technical program, which includes an increasing number of papers on nanomaterials, additive manufacturing for energy systems, actuators, energy storage, harvesting strategies and integrated energy harvesting systems, for example. This year's technical program is highlighted by six plenary talks from prominent experts on piezoelectrics, robotic insects, thermoelectrics, photovoltaics, nanocomposite cathodes, and thermal energy conversion systems. The contributed program received a large number of abstract submissions this year, 169 in total. After careful review by the 34-member Technical Program Committee, a total of 135 papers were selected for presentation. The 60 contributed oral presentations are arranged in two parallel sessions. The 75 posters

  18. Energy conversion and management principles and applications

    CERN Document Server

    Petrecca, Giovanni

    2014-01-01

    This book provides an overall view of energy conversion and management in industry and in buildings by following the streams of energy from the site boundaries to the end users. Written for an audience of both practitioners and faculty/students, Energy Conversion and Management: Principles and Applications presents general principles of energy conversion and energy sources, both traditional and renewable, in a broad range of facilities such as electrical substations, boiler plants, heat and power plants, electrical networks, thermal fluid distributions lines and insulations, pumps and fans, ai

  19. Advantages and implications of U233 fueled thermionic space power energy conversion

    International Nuclear Information System (INIS)

    Terrell, C.W.

    1992-01-01

    In this paper two recent analyses are reported which demonstrate advantages of a U233 fueled thermionic fuel element (TFE) compared to 93 w/o U235, and that application (mission) has broad latitude in how space power reactor systems could or should be optimized. A reference thermionic reactor system was selected to provide the basis for the fuel comparisons. Both oxide and metal fuel forms were compared. Of special interest was to estimate the efficiencies of the four fuel forms to produce electrical power. A figure of merit (FOM) was defined which is directly proportional to the electrical average electrical power produced is proportional to the electrical power produced per unit uranium mass. In a TFE the average electrical power produced is proportional to the emitter surface area (Esa), hence the ratio Esa/Mu was selected as the FOM. Results indicate that the choice of fuel type and form leads to wide variations in critical and system masses FOM values, and system total power

  20. Ocean thermal energy conversion (OTEC) power system development. Preliminary design report, Appendices, Part 1 (Final)

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    The objective of this project is the development of a preliminary design for a full-sized, closed cycle, ammonia power system module for the 100 MWe OTEC demonstration plant. In turn, this demonstration plant is to demonstrate, by 1984, the operation and performance of an Ocean Thermal Power Plant having sufficiently advanced heat exchanger design to project economic viability for commercial utilization in the late 1980's and beyond. Included in this power system development are the preliminary designs for a proof-of-concept pilot plant and test article heat exchangers which are scaled in such a manner as to support a logically sequential, relatively low-cost development of the full-scale power system module. The conceptual designs are presented for the demonstration plant power module, the proof-of-concept pilot plant, and for a pair of test article heat exchangers. Costs associated with the design, development, fabrication, checkout, delivery, installation, and operation are included. The accompanying design and producibilty studies on the full-scale power system module project the performance/economics for the commercial plant. This section of the report contains appendices on the developed computer models, water system dynamic studies, miscellaneous performance analysis, materials and processes, detailed equipment lists, turbine design studies, tube cleaner design, ammonia leak detection, and heat exchanger design supporting data. (WHK)

  1. Solar energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Kistler, J.

    1981-08-05

    The photovoltaic generator is the central part of all solar systems. Flat solar cells embedded in glass are preferred which can also convert diffuse solar radiation. Hybrid modules generate electrical and thermal energy simultaneously. With decreasing generator cost, the cost of energy storage becomes critical. Development activities are mostly directed on the development of stationary lead accumulator batteries and the electronic charging and protective systems. The block diagram of the current converter is presented, and applications of solar systems in domestic heating engineering, transportation technology, communications, and hydrological engineering. Solar villages are recommended which, established in bilateral cooperation with Third World authorities, may demonstrate the advantages of solar energy in heat and electric power generation.

  2. Research in Support of the Use of Rankine Cycle Energy Conversion Systems for Space Power and Propulsion

    Science.gov (United States)

    Lahey, Richard T., Jr.; Dhir, Vijay

    2004-01-01

    This is the report of a Scientific Working Group (SWG) formed by NASA to determine the feasibility of using a liquid metal cooled nuclear reactor and Rankine energy conversion cycle for dual purpose power and propulsion in space. This is a high level technical report which is intended for use by NASA management in program planning. The SWG was composed of a team of specialists in nuclear energy and multiphase flow and heat transfer technology from academia, national laboratories, NASA and industry. The SWG has identified the key technology issues that need to be addressed and have recommended an integrated short term (approx. 2 years) and a long term (approx. 10 year) research and development (R&D) program to qualify a Rankine cycle power plant for use in space. This research is ultimately intended to give NASA and its contractors the ability to reliably predict both steady and transient multiphase flow and heat transfer phenomena at reduced gravity, so they can analyze and optimize designs and scale-up experimental data on Rankine cycle components and systems. In addition, some of these results should also be useful for the analysis and design of various multiphase life support and thermal management systems being considered by NASA.

  3. WIND ENERGY CONVERSION SYSTEMS - A TECHNICAL REVIEW

    Directory of Open Access Journals (Sweden)

    N. RAMESH BABU

    2013-08-01

    Full Text Available Wind power production has been under the main focus for the past decade in power production and tremendous amount of research work is going on renewable energy, specifically on wind power extraction. Wind power provides an eco-friendly power generation and helps to meet the national energy demand when there is a diminishing trend in terms of non-renewable resources. This paper reviews the modeling of Wind Energy Conversion Systems (WECS, control strategies of controllers and various Maximum Power Point Tracking (MPPT technologies that are being proposed for efficient production of wind energy from the available resource.

  4. State of the art on power performance assessments for wind energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Maribo Pedersen, B. [ed.

    1997-12-31

    It is the intention of this meeting to clarify the status of power performance verification and assessment and identify the future needs in terms of applications, research fields and standardization actions, putting emphasis on the following items: Power performance verification for wind farms; Power performance verification for large wind turbines; Power performance verification for wind turbines operating in complex terrain; Assessment of the available international and national standards; Assessment of developed, applied and verified tools for WECS power performance. This Experts Meeting had gathered 14 participants from 6 different countries. 12 presentations were given and although countries with a sizeable wind program, ie. Italy, UK and Spain were not present, it is felt that the meeting gave a fair impression of the contemporary state of the art world wide. Specific problems concerning accurate definition and measurement of wind speed by cup-anemometers were dealt with. Different sources of errors were analysed and valuable new experimental results were presented. Other instruments for wind-speed measurements than cup-anemometers were discussed as well. (EG)

  5. Direct conversion of light to radio frequency energy. [using photoklystrons for solar power satellites

    Science.gov (United States)

    Freeman, J. W.; Simons, S.

    1981-01-01

    A description is presented of the test results obtained with the latest models of the phototron. The phototron was conceived as a replacement for the high voltage solar cell-high power klystron combination for the solar power satellite concept. Physically, the phototron is a cylindrical evacuated glass tube with a photocathode, two grids, and a reflector electrode in a planar configuration. The phototron can be operated either in a biased mode where a low voltage is used to accelerate the electron beam produced by the photocathode or in an unbiased mode referred to as self-oscillation. The device is easily modulated by light input or voltage to broadcast in AM or FM. The range of operation of the present test model phototrons is from 2 to 200 MHz.

  6. Solar-energy conversion system provides electrical power and thermal control for life-support systems

    Science.gov (United States)

    Davis, B. K.

    1974-01-01

    System utilizes Freon cycle and includes boiler turbogenerator with heat exchanger, regenerator and thermal-control heat exchangers, low-pressure and boiler-feed pumps, and condenser. Exchanger may be of interest to engineers and scientists investigating new energy sources.

  7. Geothermal energy conversion facility

    Energy Technology Data Exchange (ETDEWEB)

    Kutscher, C.F.

    1997-12-31

    With the termination of favorable electricity generation pricing policies, the geothermal industry is exploring ways to improve the efficiency of existing plants and make them more cost-competitive with natural gas. The Geothermal Energy Conversion Facility (GECF) at NREL will allow researchers to study various means for increasing the thermodynamic efficiency of binary cycle geothermal plants. This work has received considerable support from the US geothermal industry and will be done in collaboration with industry members and utilities. The GECF is being constructed on NREL property at the top of South Table Mountain in Golden, Colorado. As shown in Figure 1, it consists of an electrically heated hot water loop that provides heating to a heater/vaporizer in which the working fluid vaporizes at supercritical or subcritical pressures as high as 700 psia. Both an air-cooled and water-cooled condenser will be available for condensing the working fluid. In order to minimize construction costs, available equipment from the similar INEL Heat Cycle Research Facility is being utilized.

  8. Variable-speed wind power system with improved energy capture via multilevel conversion

    Science.gov (United States)

    Erickson, Robert W.; Al-Naseem, Osama A.; Fingersh, Lee Jay

    2005-05-31

    A system and method for efficiently capturing electrical energy from a variable-speed generator are disclosed. The system includes a matrix converter using full-bridge, multilevel switch cells, in which semiconductor devices are clamped to a known constant DC voltage of a capacitor. The multilevel matrix converter is capable of generating multilevel voltage wave waveform of arbitrary magnitude and frequencies. The matrix converter can be controlled by using space vector modulation.

  9. TFTR power conversion and plasma feedback systems

    International Nuclear Information System (INIS)

    Neumeyer, C.

    1985-01-01

    Major components of the Tokamak Fusion Test Reactor (TFTR) power conversion system include 39 thyristor rectifier power supplies, 12 energy storage capacitor banks, and 6 ohmic heating interrupters. These components are connected in various series/parallel configurations to provide controlled pulses of current to the Toroidal Field (TF), Ohmic Heating (OH), Equilibrium (vertical) Field (EF), and Horizontal Field (HF) magnet coil systems. Real-time control of the power conversion system is accomplished by a centralized dedicated computer; local control is minimal. Power supply firing angles, capacitor bank charge and discharge commands, interrupter commands, etc., are all determined and issued by the central computer. Plasma Position and Current Control (PPCC) reference signals to power conversion (OH, EF, HF) are determined by separate analog electronics but invoked through the power conversion computer. Real-time fault sensing of plasma parameters, gas injection, neutral beams, etc., are monitored by a separate Discharge Fault System (DFS) but routed through the power conversion computer for pre-programmed shutdown response

  10. Investigation of heat exchangers for energy conversion systems of megawatt-class space power plants

    Science.gov (United States)

    Ilmov, D. N.; Mamontov, Yu. N.; Skorohodov, A. S.; Smolyarov, V. A.; Filatov, N. I.

    2016-01-01

    The specifics of operation (high temperatures in excess of 1000 K and large pressure drops of several megapascals between "hot" and "cold" coolant paths) of heat exchangers in the closed circuit of a gasturbine power converter operating in accordance with the Brayton cycle with internal heat recovery are analyzed in the context of construction of space propulsion systems. The design of a heat-exchange matrix made from doubly convex stamped plates with a specific surface relief is proposed. This design offers the opportunity to construct heat exchangers with the required parameters (strength, rigidity, weight, and dimensions) for the given operating conditions. The diagram of the working area of a test bench is presented, and the experimental techniques are outlined. The results of experimental studies of heat exchange and flow regimes in the models of heat exchangers with matrices containing 50 and 300 plates for two pairs of coolants (gas-gas and gas-liquid) are detailed. A criterion equation for the Nusselt number in the range of Reynolds numbers from 200 to 20 000 is proposed. The coefficients of hydraulic resistance for each coolant path are determined as functions of the Reynolds number. It is noted that the pressure in the water path in the "gas-liquid" series of experiments remained almost constant. This suggests that no well-developed processes of vaporization occurred within this heat-exchange matrix design even when the temperature drop between gas and water was as large as tens or hundreds of degrees. The obtained results allow one to design flight heat exchangers for various space power plants.

  11. Cooptimization of Adhesion and Power Conversion Efficiency of Organic Solar Cells by Controlling Surface Energy of Buffer Layers.

    Science.gov (United States)

    Lee, Inhwa; Noh, Jonghyeon; Lee, Jung-Yong; Kim, Taek-Soo

    2017-10-25

    Here, we demonstrate the cooptimization of the interfacial fracture energy and power conversion efficiency (PCE) of poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT)-based organic solar cells (OSCs) by surface treatments of the buffer layer. The investigated surface treatments of the buffer layer simultaneously changed the crack path and interfacial fracture energy of OSCs under mechanical stress and the work function of the buffer layer. To investigate the effects of surface treatments, the work of adhesion values were calculated and matched with the experimental results based on the Owens-Wendt model. Subsequently, we fabricated OSCs on surface-treated buffer layers. In particular, ZnO layers treated with poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) simultaneously satisfied the high mechanical reliability and PCE of OSCs by achieving high work of adhesion and optimized work function.

  12. EDITORIAL: The 7th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion Applications (PowerMEMS 2007)

    Science.gov (United States)

    Hebling, C.; Woias, P.

    2008-10-01

    This special issue of Journal of Micromechanics and Microengineering (JMM) contains a selection of papers from the 7th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion (PowerMEMS 2007). The workshop was held in Freiburg, Germany on 27-29 November 2007 under the joint organization of the Fraunhofer Institute for Solar Energy Systems (FhG-ISE), Freiburg and the Department of Microsystems Engineering (IMTEK) of the Albert-Ludwig-University of Freiburg. PowerMEMS 2007 continues a series of workshops initiated in 2000 in Japan to create an annual discussion forum in the emerging field of micro energy technology. With a single exception in 2001, the workshop has continued as an annual meeting ever since, with a continuous increase in the number of presentations and participants. The program of PowerMEMS 2007 was composed of 2 invited talks, 25 oral talks and 61 poster presentations. From these 88 presentations 16 have been selected for this special issue. It was at the end of 1959 when the Caltech physicist Richard Feynman gave his famous lecture entitled 'There Is Plenty of Room at the Bottom' in which he discussed the possibilities of miniaturization for both storage capacity ('Encyclopaedia Britannica on the head of a pin') as well as micro machining ('rearranging the atoms'), although there were absolutely no technological possibilities in sight for an adequate realization of such ideas. Now, nearly 50 years later, we not only have incredible knowledge about the nanoworld, but even more we are now able to generate microelectromechanical devices which, next to their electronic properties, can integrate physical and analytical functions. Today, Feynman might easily have added a second lecture entitled 'There is Plenty of Energy at the Bottom'. Micro energy technology has seen a tremendous rise in MEMS and material sciences and is regarded today as one of their hot topics. Also, there are more and more companies in this

  13. EDITORIAL: Selected papers from the 11th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2011) Selected papers from the 11th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2011)

    Science.gov (United States)

    Cho, Young-Ho

    2012-09-01

    This special section of Journal of Micromechanics and Microengineering features papers selected from the 11th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2011), held at Sejong Hotel in Seoul, Korea during 15-18 November 2011. Since the first PowerMEMS workshop held in Sendai, Japan in 2000, the workshop has developed as the premier forum for reporting research results in micro and nanotechnology for power generation, energy conversion, harvesting and processing applications, including in-depth technical issues on nanostructures and materials for small-scale high-density energy and thermal management. Potential PowerMEMS applications cover not only portable power devices for consumer electronics and remote sensors, but also micro engines, impulsive thrusters and fuel cells for systems ranging from the nanometer to the millimeter scale. The 2011 technical program consists of 1 plenary talk, 4 invited talks and 118 contributed presentations. The 48 oral and 70 poster presentations, selected by 27 Technical Program Committee Members from 131 submitted abstracts, have stimulated lively discussion maximizing the interaction between participants. Among them, this special section includes 9 papers covering micro-scale power generators, energy converters, harvesters, thrusters and thermal coolers. Finally, we are grateful to the members of the International Steering Committee, the Technical Program Committee, and the Local Organizing Committee for their efforts and contributions to PowerMEMS 2011. We also thank the two companies Samsung Electro-Mechanics and LG Elite for technical tour arrangements. Special thanks go to Dr Ian Forbes, the editorial staff of the Journal of Micromechanics and Microengineering, as well as to the staff of IOP Publishing for making this special section possible.

  14. Materials and design concerning magnetohydrodynamic channels of direct power conversion from combustion gases thermal energy into electricity

    International Nuclear Information System (INIS)

    Yerouchalmi, David

    1970-01-01

    Direct power conversion of thermal energy into electricity by magnetohydrodynamic is defined through thermodynamic cycles of hot gases; the present work concerning only the channel-generator operating with fossil gases in open cycle. Insulating walls and electrodes are subject initially to general apparent working conditions and those are followed by several others which appear only when experimental stage is reached. First, a choice has to be made between cold walls and hot walls which have been both closely investigated. But experience and theory lead to a third solution: viz controlled temperature walls and to consequent thermal exchange design. Many additional phenomena such as: solid state electrolysis, vaporisation, corrosion and alkali seed migration are analysed; then some solutions are described, tried and suggested. Same is given for mechanical, cooling devices, cold electric junctions and current relays. Experimental devices and work done on several solutions are described and results given. New prospects are suggested; and, in conclusion, the subject still appears to merit quite an important amount of further research. (author) [fr

  15. Ocean thermal-energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Ford, G; Niblett, C; Walker, L

    1983-03-01

    Ocean thermal-energy conversion (OTEC) is a novel 'alternative' energy technology that has created much interest in a number of countries; namely, the USA, Japan, France, Sweden, Holland, India and most recently, the UK. In particular, the first three of these have had programmes to develop the required technology. However, most interest has been centred in the USA, where the current hiatus in Federal funding provides a timely opportunity to assess progress. This paper offers a survey of the prevailing position there; outlining the outstanding technical and associated problems, and likely future developments. Non-USA programmes are only mentioned to contrast them with the American position. At present, it does not appear that OTEC plants will be commercially viable on a widespread basis even in the tropics. This is particularly true of the larger plants (400 MWe, MWe = megawatts of electrical energy, the final output of a power station) towards which the American programme is ultimately geared. There does seem to be a strong possibility that small OTEC plants, around 40 MWe or less, can be commercial in certain circumstances. This would be possible when one or, preferably, more of the following conditions are met: (i) where a land-based rather than 'at sea' plant is possible, (ii) where alternative energy supplies are at a premium, i.e. islands or regions without indigenous energy supplies, and (iii) where conditions are such that an OTEC plant could operate in conjunction with either or both an aquaculture or desalination plant.

  16. Optical Energy Transfer and Conversion System

    Science.gov (United States)

    Hogan, Bartholomew P. (Inventor); Stone, William C. (Inventor)

    2018-01-01

    An optical energy transfer and conversion system comprising a fiber spooler and an electrical power extraction subsystem connected to the spooler with an optical waveguide. Optical energy is generated at and transferred from a base station through fiber wrapped around the spooler, and ultimately to the power extraction system at a remote mobility platform for conversion to another form of energy. The fiber spooler may reside on the remote mobility platform which may be a vehicle, or apparatus that is either self-propelled or is carried by a secondary mobility platform either on land, under the sea, in the air or in space.

  17. Synchronous generator wind energy conversion control system

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, A.L.R. [Wind Energy Group, Recife (Brazil); Lima, A.M.N.; Jacobina, C.B.; Simoes, F.J. [DEE, Campina Grande (Brazil)

    1996-12-31

    This paper presents the performance evaluation and the design of the control system of a WECS (Wind Energy Conversion System) that employs a synchronous generator based on its digital simulation. The WECS discussed in this paper is connected to the utility grid through two Pulse Width Modulated (PWM) power converters. The structure of the proposed WECS enables us to achieve high performance energy conversion by: (i) maximizing the wind energy capture and (ii) minimizing the reactive power flowing between the grid and the synchronous generator. 8 refs., 19 figs.

  18. Microturbine Power Conversion Technology Review

    Energy Technology Data Exchange (ETDEWEB)

    Staunton, R.H.

    2003-07-21

    In this study, the Oak Ridge National Laboratory (ORNL) is performing a technology review to assess the market for commercially available power electronic converters that can be used to connect microturbines to either the electric grid or local loads. The intent of the review is to facilitate an assessment of the present status of marketed power conversion technology to determine how versatile the designs are for potentially providing different services to the grid based on changes in market direction, new industry standards, and the critical needs of the local service provider. The project includes data gathering efforts and documentation of the state-of-the-art design approaches that are being used by microturbine manufacturers in their power conversion electronics development and refinement. This project task entails a review of power converters used in microturbines sized between 20 kW and 1 MW. The power converters permit microturbine generators, with their non-synchronous, high frequency output, to interface with the grid or local loads. The power converters produce 50- to 60-Hz power that can be used for local loads or, using interface electronics, synchronized for connection to the local feeder and/or microgrid. The power electronics enable operation in a stand-alone mode as a voltage source or in grid-connect mode as a current source. Some microturbines are designed to automatically switch between the two modes. The information obtained in this data gathering effort will provide a basis for determining how close the microturbine industry is to providing services such as voltage regulation, combined control of both voltage and current, fast/seamless mode transfers, enhanced reliability, reduced cost converters, reactive power supply, power quality, and other ancillary services. Some power quality improvements will require the addition of storage devices; therefore, the task should also determine what must be done to enable the power conversion circuits to

  19. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 8: Open-cycle MHD. [energy conversion efficiency and design analysis of electric power plants employing magnetohydrodynamics

    Science.gov (United States)

    Hoover, D. Q.

    1976-01-01

    Electric power plant costs and efficiencies are presented for three basic open-cycle MHD systems: (1) direct coal fired system, (2) a system with a separately fired air heater, and (3) a system burning low-Btu gas from an integrated gasifier. Power plant designs were developed corresponding to the basic cases with variation of major parameters for which major system components were sized and costed. Flow diagrams describing each design are presented. A discussion of the limitations of each design is made within the framework of the assumptions made.

  20. Energy conversion at dipolarization fronts

    Science.gov (United States)

    Khotyaintsev, Yu. V.; Divin, A.; Vaivads, A.; André, M.; Markidis, S.

    2017-02-01

    We use multispacecraft observations by Cluster in the Earth's magnetotail and 3-D particle-in-cell simulations to investigate conversion of electromagnetic energy at the front of a fast plasma jet. We find that the major energy conversion is happening in the Earth (laboratory) frame, where the electromagnetic energy is being transferred from the electromagnetic field to particles. This process operates in a region with size of the order several ion inertial lengths across the jet front, and the primary contribution to E·j is coming from the motional electric field and the ion current. In the frame of the front we find fluctuating energy conversion with localized loads and generators at sub-ion scales which are primarily related to the lower hybrid drift instability excited at the front; however, these provide relatively small net energy conversion.

  1. Fundamentals of thermophotovoltaic energy conversion

    CERN Document Server

    Chubb, Donald L

    2007-01-01

    This is a text book presenting the fundamentals of thermophotovoltaic(TPV) energy conversion suitable for an upper undergraduate or first year graduate course. In addition it can serve as a reference or design aid for engineers developing TPV systems. Mathematica design programs for interference filters and a planar TPV system are included on a CD-Rom disk. Each chapter includes a summary and concludes with a set of problems. The first chapter presents the electromagnetic theory and radiation transfer theory necessary to calculate the optical properties of the components in a TPV optical cavity. Using a simplified model, Chapter 2 develops expressions for the maximum efficiency and power density for an ideal TPV system. The next three chapters consider the three major components in a TPV system; the emitter, filter and photovoltaic(PV) array. Chapter 3 applies the electromagnetic theory and radiation transfer theory presented in Chapter 1 in the calculation of spectral emittance. From the spectral emittance t...

  2. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 10: Liquid-metal MHD systems. [energy conversion efficiency of electric power plants using liquid metal magnetohydrodynamics

    Science.gov (United States)

    Holman, R. R.; Lippert, T. E.

    1976-01-01

    Electric Power Plant costs and efficiencies are presented for two basic liquid-metal cycles corresponding to 922 and 1089 K (1200 and 1500 F) for a commercial applications using direct coal firing. Sixteen plant designs are considered for which major component equipment were sized and costed. The design basis for each major component is discussed. Also described is the overall systems computer model that was developed to analyze the thermodynamics of the various cycle configurations that were considered.

  3. Condenser design for AMTEC power conversion

    Science.gov (United States)

    Crowley, Christopher J.

    1991-01-01

    The condenser and the electrodes are the two elements of an alkali metal thermal-to-electric conversion (AMTEC) cell which most greatly affect the energy conversion performance. A condenser is described which accomplishes two critical functions in an AMTEC cell: management of the fluid under microgravity conditions and optimization of conversion efficiency. The first function is achieved via the use of a controlled surface shape, along with drainage grooves and arteries to collect the fluid. Capillary forces manage the fluid in microgravity and dominate hydrostatic effects on the ground so the device is ground-testable. The second function is achieved via a smooth film of highly reflective liquid sodium on the condensing surface, resulting in minimization of parasitic heat losses due to radiation heat transfer. Power conversion efficiencies of 25 percent to 30 percent are estimated with this condenser using present technology for the electrodes.

  4. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 6: Closed-cycle gas turbine systems. [energy conversion efficiency in electric power plants

    Science.gov (United States)

    Amos, D. J.; Fentress, W. K.; Stahl, W. F.

    1976-01-01

    Both recuperated and bottomed closed cycle gas turbine systems in electric power plants were studied. All systems used a pressurizing gas turbine coupled with a pressurized furnace to heat the helium for the closed cycle gas turbine. Steam and organic vapors are used as Rankine bottoming fluids. Although plant efficiencies of over 40% are calculated for some plants, the resultant cost of electricity was found to be 8.75 mills/MJ (31.5 mills/kWh). These plants do not appear practical for coal or oil fired plants.

  5. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 9: Closed-cycle MHD. [energy conversion efficiency of electric power plants using magnetohydrodynamics

    Science.gov (United States)

    Tsu, T. C.

    1976-01-01

    A closed-cycle MHD system for an electric power plant was studied. It consists of 3 interlocking loops, an external heating loop, a closed-cycle cesium seeded argon nonequilibrium ionization MHD loop, and a steam bottomer. A MHD duct maximum temperature of 2366 K (3800 F), a pressure of 0.939 MPa (9.27 atm) and a Mach number of 0.9 are found to give a topping cycle efficiency of 59.3%; however when combined with an integrated gasifier and optimistic steam bottomer the coal to bus bar efficiency drops to 45.5%. A 1978 K (3100 F) cycle has an efficiency of 55.1% and a power plant efficiency of 42.2%. The high cost of the external heating loop components results in a cost of electricity of 21.41 mills/MJ (77.07 mills/kWh) for the high temperature system and 19.0 mills/MJ (68.5 mills/kWh) for the lower temperature system. It is, therefore, thought that this cycle may be more applicable to internally heated systems such as some futuristic high temperature gas cooled reactor.

  6. Wind Energy Conversion Systems Technology and Trends

    CERN Document Server

    2012-01-01

    Wind Energy Conversion System covers the technological progress of wind energy conversion systems, along with potential future trends. It includes recently developed wind energy conversion systems such as multi-converter operation of variable-speed wind generators, lightning protection schemes, voltage flicker mitigation and prediction schemes for advanced control of wind generators. Modeling and control strategies of variable speed wind generators are discussed, together with the frequency converter topologies suitable for grid integration. Wind Energy Conversion System also describes offshore farm technologies including multi-terminal topology and space-based wind observation schemes, as well as both AC and DC based wind farm topologies. The stability and reliability of wind farms are discussed, and grid integration issues are examined in the context of the most recent industry guidelines. Wind power smoothing, one of the big challenges for transmission system operators, is a particular focus. Fault ride th...

  7. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 7: Metal vapor Rankine topping-steam bottoming cycles. [energy conversion efficiency in electric power plants

    Science.gov (United States)

    Deegan, P. B.

    1976-01-01

    Adding a metal vapor Rankine topper to a steam cycle was studied as a way to increase the mean temperature at which heat is added to the cycle to raise the efficiency of an electric power plant. Potassium and cesium topping fluids were considered. Pressurized fluidized bed or pressurized (with an integrated low-Btu gasifier) boilers were assumed. Included in the cycles was a pressurizing gas turbine with its associated recuperator, and a gas economizer and feedwater heater. One of the ternary systems studied shows plant efficiency of 42.3% with a plant capitalization of $66.7/kW and a cost of electricity of 8.19 mills/MJ (29.5 mills/kWh).

  8. Voltage Gain Derivation Based on Energy-Balanced Criterion for a Novel Hybrid-Input PV-Wind Power Conversion System

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2015-01-01

    Full Text Available This paper applies energy-balanced criterion to a novel hybrid-input PV-wind power conversion system (HPWPCS for voltage gain derivation. With the energy-balanced concept, complicated mathematical problems related to voltage gain derivation can be readily resolved. Based on the derived results, it is proven that the proposed HPWPCS is able to process two different kinds of renewable energy resources simultaneously. Even though the HPWPCS includes seven capacitors and three magnetic components, its voltage gain still can be found by the mathematical analysis. In the theoretical derivation, only the energy status of output inductor is dealt with such that complicated derivation procedure is avoided. This analysis method can also be applied to other hybrid green-energy conversion systems. In this paper, a 200 W 50 kHz prototype of HPWPCS is built and examined to verify the mathematical results.

  9. Photovoltaic Energy Conversion Systems

    DEFF Research Database (Denmark)

    Kouro, Samir; Wu, Bin; Abu-Rub, Haitham

    2014-01-01

    This chapter presents a comprehensive overview of grid-connected PV systems, including power curves, grid-connected configurations, different converter topologies (both single- and three-phase), control schemes, MPPT, and anti-islanding detection methods. The focus of the chapter has been on the ...

  10. A reduced switch count UPF power conditioner for grid connected variable speed wind energy conversion system employing PM generators: a simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Raju, A.B.; Fernandes, B.G.; Chatterjee, K. [Indian Institute of Technology, Mumbai (India). Dept. of Electrical Engineering

    2004-07-01

    In this paper, modelling and simulation of a grid connected variable speed wind energy conversion system (VSWECS) with reduced switch count power converter is presented. The system consists of a permanent magnet synchronous generator (PMSG), two-pulse width modulated B-4 power converters and a maximum power point tracker (MPPT). Mathematical models of each element of the system are developed separately and are then integrated to simulate the whole system for various wind velocities. The complete system is simulated using MATLAB/SIMULINK and simulation results are presented. (author)

  11. Flexible energy conversion

    International Nuclear Information System (INIS)

    Griepentrog, H.

    1975-01-01

    A helium turbine was started up at the Oberhausen heating power station in December 1974. The practical experience with this system will be useful later for helium-cooled HTR type reactors with gas turbines in the coolant loop. The first report in VDI-Nachrichten 11/75 is followed below by a detailed description of the Oberhausen pilot plant. (orig./AK) [de

  12. Proceedings of the 25th intersociety energy conversion engineering conference

    International Nuclear Information System (INIS)

    Nelson, P.A.; Schertz, W.W.; Till, R.H.

    1990-01-01

    This book contains the proceedings of the 25th intersociety energy conversion engineering conference. Volume 1 is organized under the following headings: space power systems requirements and issues, space power systems; space power systems 2; space nuclear power reactors space nuclear reactor technology I; space nuclear reactor technology II; reactor technology; isotopic fueled power systems I, isotopic fueled power systems II, space power automation; space power automation II, space power automation III; space power automation IV; space power automation V; power systems hardware and design selection, power components, pulse power, power management and distribution, power management and distribution II, power management and distribution III; space energy conversion: solar dynamic, space energy conversion: static and dynamic, space solar array technology, advanced space solar cells

  13. Solar energy conversion. Chemical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Likhtenshtein, Gertz [Ben-Gurion Univ. of the Negev, Beersheba (Israel). Dept. of Chemistry

    2012-07-01

    Finally filling a gap in the literature for a text that also adopts the chemist's view of this hot topic, Professor Likhtenshtein, an experienced author and internationally renowned scientist, considers different physical and engineering aspects in solar energy conversion. From theory to real-life systems, he shows exactly which chemical reactions take place when converting light energy, providing an overview of the chemical perspective from fundamentals to molecular harvesting systems and solar cells. This essential guide will thus help researchers in academia and industry better understand solar energy conversion, and so ultimately help this promising, multibillion euro/dollar field to expand. (orig.)

  14. Energy conversion and utilization technologies

    International Nuclear Information System (INIS)

    1988-01-01

    The DOE Energy Conversion and Utilization Technologies (ECUT) Program continues its efforts to expand the generic knowledge base in emerging technological areas that support energy conservation initiatives by both the DOE end-use sector programs and US private industry. ECUT addresses specific problems associated with the efficiency limits and capabilities to use alternative fuels in energy conversion and end-use. Research is aimed at understanding and improving techniques, processes, and materials that push the thermodynamic efficiency of energy conversion and usage beyond the state of the art. Research programs cover the following areas: combustion, thermal sciences, materials, catalysis and biocatalysis, and tribology. Six sections describe the status of direct contact heat exchange; the ECUT biocatalysis project; a computerized tribology information system; ceramic surface modification; simulation of internal combustion engine processes; and materials-by-design. These six sections have been indexed separately for inclusion on the database. (CK)

  15. Evolution of energy conversion plants

    International Nuclear Information System (INIS)

    Osnaghi, C.

    2001-01-01

    The paper concerns the evolution and the future development of energy conversion plants and puts into evidence the great importance of the scientific and technological improvement in machines design, in order to optimize the use of energy resources and to improve ambient compatibility [it

  16. Photovoltaic conversion of laser energy

    Science.gov (United States)

    Stirn, R. J.

    1976-01-01

    The Schottky barrier photovoltaic converter is suggested as an alternative to the p/n junction photovoltaic devices for the conversion of laser energy to electrical energy. The structure, current, output, and voltage output of the Schottky device are summarized. The more advanced concepts of the multilayer Schottky barrier cell and the AMOS solar cell are briefly considered.

  17. Situation of nuclear power generation in Sweden: swaying nuclear energy policy and conversion from nuclear phase-out policy

    International Nuclear Information System (INIS)

    Kuroda, Yuji

    2017-01-01

    In Sweden, fossil fuels cannot be produced domestically, and most of them depend on foreign imports. For this reason, together with hydropower generation using abundant water resources, nuclear power generation was introduced and used since the early stage. Nuclear power generation in 2015 reached 35% of total generated power energy. As of 2016, Sweden was steadily constructing the world's second final disposal site of high-level radioactive waste. On the other hand, this country is known as the one that decided nuclear phase-out policy earliest in the world. However, the country's nuclear policy is swaying together with changes in political party power due to election results. In 1980, they decided the policy of abolishing all nuclear power generation by 2010. Thereafter, the nuclear phase-out policy was frozen and maximum 10 units of nuclear plants were accepted. The goal of the latest policy is to allow new construction up to 10 units as replacement, and to use 100% of renewable energy in 2040. However, the year of 2040 is not a deadline for the abolishment of nuclear power generation. In Sweden's public opinion on nuclear power generation, the early abolition was dominant at about 50% during 1986∼1995, but this opinion decreased to about 10% in the 2000s. There is an increasing number of opinions saying that the existing nuclear plants should be continuously operated for a while, and phased out step by step in the future. (A.O.)

  18. Development of sensor-less control strategies for grid connected PMSG based variable speed wind energy conversion system with improved power quality features

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, A. [Quebec Univ., Montreal, PQ (Canada). Dept. of Electrical Engineering

    2010-07-01

    Interest in renewable energy sources has grown in recent years in response to concerns of increasing pollution levels and depleting fossil fuels. Among renewable energy sources, wind energy generation is the fastest growing technology and one of the most cost-effective and environmental friendly means to generate electricity from renewable sources. Modern wind turbines are ready to be deployed in large scale as a result of recent developments in wind power technology. Variable speed permanent magnet synchronous generators (PMSG) based wind energy conversion systems (WECS) are becoming more popular. The use of a permanent magnet reduces size, cost and weight of overall WECS. In addition, the absence of field winding and its excitation system avoids heat dissipation in the rotor winding, thereby improving overall efficiency of the WECS. This type of configuration is more appropriate for remote locations, particularly for off-shore wind application, where the geared doubly fed induction generator usually requires regular maintenance due to tearing-wearing in brushes, windings and gear box. This presentation discussed the development of sensor-less control strategies for grid connected PMSG based variable speed wind energy conversion system with improved power quality features. A novel adaptive network-based fuzzy inference system was used to estimate the speed and position of variable speed PMSG under fluctuating wind conditions. A novel control strategy was developed for the grid interfacing inverter incorporating power quality improvement features at point of common coupling.

  19. Energy Conversion Alternatives Study (ECAS)

    Science.gov (United States)

    1977-01-01

    ECAS compared various advanced energy conversion systems that can use coal or coal-derived fuels for baseload electric power generation. It was conducted in two phases. Phase 1 consisted of parametric studies. From these results, 11 concepts were selected for further study in Phase 2. For each of the Phase 2 systems and a common set of ground rules, performance, cost, environmental intrusion, and natural resource requirements were estimated. In addition, the contractors defined the state of the associated technology, identified the advances required, prepared preliminary research and development plans, and assessed other factors that would affect the implementation of each type of powerplant. The systems studied in Phase 2 include steam systems with atmospheric- and pressurized-fluidized-bed boilers; combined cycle gas turbine/steam systems with integrated gasifiers or fired by a semiclean, coal derived fuel; a potassium/steam system with a pressurized-fluidized-bed boiler; a closed-cycle gas turbine/organic system with a high-temperature, atmospheric-fluidized-bed furnace; a direct-coal-fired, open- cycle magnetohydrodynamic/steam system; and a molten-carbonate fuel cell/steam system with an integrated gasifier. The sensitivity of the results to changes in the ground rules and the impact of uncertainties in capital cost estimates were also examined.

  20. Effects of upgrading systems on energy conversion efficiency of a gasifier - fuel cell - gas turbine power plant

    International Nuclear Information System (INIS)

    Pedrazzi, Simone; Allesina, Giulio; Tartarini, Paolo

    2016-01-01

    Highlights: • An advanced gasifier-SOFC-MGT system is modeled. • An overall electrical efficiency of 32.81% is reached. • Influence of all the sub-system modeled on the power plant efficiency is discussed. • Compression storage of syngas is taken into account. - Abstract: This work focuses on a DG-SOFC-MGT (downdraft gasifier - solid oxide fuel cell - micro gas turbine) power plant for electrical energy production and investigates two possible performance-upgrading systems: polyphenylene oxide (PPO) membrane and zeolite filters. The first is used to produce oxygen-enriched air used in the reactor, while the latter separates the CO_2 content from the syngas. In order to prevent power plant shutdowns during the gasifier reactor scheduled maintenance, the system is equipped with a gas storage tank. The generation unit consists of a SOFC-MGT system characterized by higher electrical efficiency when compared to conventional power production technology (IC engines, ORC and EFGT). Poplar wood chips with 10% of total moisture are used as feedstock. Four different combinations with and without PPO and zeolite filtrations are simulated and discussed. One-year energy and power simulation were used as basis for comparison between all the cases analyzed. The modeling of the gasification reactions gives results consistent with literature about oxygen-enriched processes. Results showed that the highest electrical efficiency obtained is 32.81%. This value is reached by the power plant equipped only with PPO membrane filtration. Contrary to the PPO filtering, zeolite filtration does not increase the SOFC-MGT unit performance while it affects the energy balance with high auxiliary electrical consumption. This solution can be considered valuable only for future work coupling a CO_2 sequestration system to the power plant.

  1. Electrical Power Conversion of River and Tidal Power Generator

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard; Gevorgian, Vahan; Wright, Alan; Donegan, James; Marnagh, Cian; McEntee, Jarlath

    2016-11-21

    As renewable generation has become less expensive during recent decades, and it becomes more accepted by the global population, the focus on renewable generation has expanded to include new types with promising future applications, such as river and tidal generation. Although the utilization of power electronics and electric machines in industry is phenomenal, the emphasis on system design is different for various sectors of industry. In precision control, robotics, and weaponry, the design emphasis is on accuracy and reliability with less concern for the cost of the final product. In energy generation, the cost of energy is the prime concern; thus, capital expenditures (CAPEX) and operations and maintenance expenditures (OPEX) are the major design objectives. This paper describes the electrical power conversion aspects of river and tidal generation. Although modern power converter control is available to control the generation side, the design was chosen on the bases of minimizing the CAPEX and OPEX; thus, the architecture is simple and modular for ease of replacement and maintenance. The power conversion is simplified by considering a simple diode bridge and a DC-DC power converter to take advantage of abundant and low-cost photovoltaic inverters that have well-proven grid integration characteristics (i.e., the capability to produce energy with good power quality and control real power and voltage on the grid side).

  2. IECEC '91; Proceedings of the 26th Intersociety Energy Conversion Engineering Conference, Boston, MA, Aug. 4-9, 1991. Vol. 1 - Aerospace power systems

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Various papers on aerospace power systems are presented. The general topics addressed are: advanced aerospace power concepts, aircraft power, analysis of PMAD performance, automation, burst and pulse power, environmental issues, power circuits, power components, simulation, solar dynamics, solar dynamics conversion cycles, space design of PMAD systems, space environmental effects, space high voltage environment, space nuclear systems, space power automation

  3. Comparison of the Energy Conversion Efficiency of a Solar Chimney and a Solar PV-Powered Fan for Ventilation Applications

    Directory of Open Access Journals (Sweden)

    Lubomír Klimeš

    2018-04-01

    Full Text Available A study into the performance of a solar chimney and a solar photovoltaic (PV-powered fan for ventilation applications was carried out using numerical simulations. The performance of the solar chimney was compared with that of a direct current (DC fan powered by a solar PV panel. The comparison was carried out using the same area of the irradiated surface—the area of the solar absorber plate in the case of the solar chimney and the area of the solar panel in the case of the photovoltaic-powered fan. The two studied cases were compared under various solar radiation intensities of incident solar radiation. The results indicate that the PV-powered fans significantly outperform solar chimneys in terms of converting solar energy into the kinetic energy of air motion. Moreover, ventilation with PV-powered fans offers more flexibility in the arrangement of the ventilation system and also better control of the air flow rates in the case of battery storage.

  4. Frontiers of Energy Storage and Conversion

    Directory of Open Access Journals (Sweden)

    Jiajun Chen

    2014-09-01

    Full Text Available This special issue of Inorganics features a Forum for novel materials and approaches for electrochemical energy storage and conversion. Diminishing non-renewable fossil fuels and the resulting unattainability of environment have made us search new sustainable energy resources and develop technology for efficient utilization of such resources. Green energy sources, such as solar, hydroelectric, thermal and wind energy are partially replacing fossil fuels as means to generate power. Inorganic (solid state materials are key in the development of advanced devices for the efficient storage and conversion of energy. The grand challenge facing the inorganic chemist is to discover, design rationally and utilize advanced technological materials made from earth-abound elements for these energy storage and conversion processes. Recent spectacular progress in inorganic materials synthesis, characterization, and computational screening has greatly advanced this field, which drove us to edit this issue to provide a window to view the development of this field for the community. This special issue comprises research articles, which highlights some of the most recent advances in new materials for energy storage and conversion. [...

  5. Algal Energy Conversion and Capture

    Science.gov (United States)

    Hazendonk, P.

    2015-12-01

    We address the potential for energy conversions and capture for: energy generation; reduction in energy use; reduction in greenhouse gas emissions; remediation of water and air pollution; protection and enhancement of soil fertility. These processes have the potential to sequester carbon at scales that may have global impact. Energy conversion and capture strategies evaluate energy use and production from agriculture, urban areas and industries, and apply existing and emerging technologies to reduce and recapture energy embedded in waste products. The basis of biocrude production from Micro-algal feedstocks: 1) The nutrients from the liquid fraction of waste streams are concentrated and fed into photo bioreactors (essentially large vessels in which microalgae are grown) along with CO2 from flue gasses from down stream processes. 2) The algae are processed to remove high value products such as proteins and beta-carotenes. The advantage of algae feedstocks is the high biomass productivity is 30-50 times that of land based crops and the remaining biomass contains minimal components that are difficult to convert to biocrude. 3) The remaining biomass undergoes hydrothermal liquefaction to produces biocrude and biochar. The flue gasses of this process can be used to produce electricity (fuel cell) and subsequently fed back into the photobioreactor. The thermal energy required for this process is small, hence readily obtained from solar-thermal sources, and furthermore no drying or preprocessing is required keeping the energy overhead extremely small. 4) The biocrude can be upgraded and refined as conventional crude oil, creating a range of liquid fuels. In principle this process can be applied on the farm scale to the municipal scale. Overall, our primary food production is too dependent on fossil fuels. Energy conversion and capture can make food production sustainable.

  6. Energy conversion technology by chemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Oh, I W; Yoon, K S; Cho, B W [Korea Inst. of Science and Technology, Seoul (Korea, Republic of); and others

    1996-12-01

    The sharp increase in energy usage according to the industry development has resulted in deficiency of energy resources and severe pollution problems. Therefore, development of the effective way of energy usage and energy resources of low pollution is needed. Development of the energy conversion technology by chemical processes is also indispensable, which will replace the pollutant-producing and inefficient mechanical energy conversion technologies. Energy conversion technology by chemical processes directly converts chemical energy to electrical one, or converts heat energy to chemical one followed by heat storage. The technology includes batteries, fuel cells, and energy storage system. The are still many problems on performance, safety, and manufacturing of the secondary battery which is highly demanded in electronics, communication, and computer industries. To overcome these problems, key components such as carbon electrode, metal oxide electrode, and solid polymer electrolyte are developed in this study, followed by the fabrication of the lithium secondary battery. Polymer electrolyte fuel cell, as an advanced power generating apparatus with high efficiency, no pollution, and no noise, has many applications such as zero-emission vehicles, on-site power plants, and military purposes. After fabricating the cell components and operating the single cells, the fundamental technologies in polymer electrolyte fuel cell are established in this study. Energy storage technology provides the safe and regular heat energy, irrespective of the change of the heat energy sources, adjusts time gap between consumption and supply, and upgrades and concentrates low grade heat energy. In this study, useful chemical reactions for efficient storage and transport are investigated and the chemical heat storage technology are developed. (author) 41 refs., 90 figs., 20 tabs.

  7. A Flexible, Stretchable and Shape-Adaptive Approach for Versatile Energy Conversion and Self-Powered Biomedical Monitoring

    KAUST Repository

    Yang, Po Kang

    2015-05-15

    A flexible triboelectric nanogenerator (FTENG) based on wavy-structured Kapton film and a serpentine electrode on stretchable substrates is presented. The as-fabricated FTENG is capable of harvesting ambient mechanical energy via both compressive and stretching modes. Moreover, the FTENG can be a bendable power source to work on curved surfaces; it can also be adaptively attached onto human skin for monitoring gentle body motions. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Waste to Energy Conversion by Stepwise Liquefaction, Gasification and "Clean" Combustion of Pelletized Waste Polyethylene for Electric Power Generation---in a Miniature Steam Engine

    Science.gov (United States)

    Talebi Anaraki, Saber

    The amounts of waste plastics discarded in developed countries are increasing drastically, and most are not recycled. The small fractions of the post-consumer plastics which are recycled find few new uses as their quality is degraded; they cannot be reused in their original applications. However, the high energy density of plastics, similar to that of premium fuels, combined with the dwindling reserves of fossil fuels make a compelling argument for releasing their internal energy through combustion, converting it to thermal energy and, eventually, to electricity through a heat engine. To minimize the emission of pollutants this energy conversion is done in two steps, first the solid waste plastics undergo pyrolytic gasification and, subsequently, the pyrolyzates (a mixture of hydrocarbons and hydrogen) are blended with air and are burned "cleanly" in a miniature power plant. This plant consists of a steam boiler, a steam engine and an electricity generator.

  9. Modeling Innovative Power Take-Off Based on Double-Acting Hydraulic Cylinders Array for Wave Energy Conversion

    Directory of Open Access Journals (Sweden)

    Juan Carlos Antolín-Urbaneja

    2015-03-01

    Full Text Available One of the key systems of a Wave Energy Converter for extraction of wave energy is the Power Take-Off (PTO device. This device transforms the mechanical energy of a moving body into electrical energy. This paper describes the model of an innovative PTO based on independently activated double-acting hydraulic cylinders array. The model has been developed using a simulation tool, based on a port-based approach to model hydraulics systems. The components and subsystems used in the model have been parameterized as real components and their values experimentally obtained from an existing prototype. In fact, the model takes into account most of the hydraulic losses of each component. The simulations show the flexibility to apply different restraining torques to the input movement depending on the geometrical configuration and the hydraulic cylinders on duty, easily modified by a control law. The combination of these two actions allows suitable flexibility to adapt the device to different sea states whilst optimizing the energy extraction. The model has been validated using a real test bench showing good correlations between simulation and experimental tests.

  10. EDITORIAL: Selected papers from the 10th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2010) Selected papers from the 10th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2010)

    Science.gov (United States)

    Reynaerts, Dominiek; Vullers, Ruud

    2011-10-01

    This special section of Journal of Micromechanics and Microengineering features papers selected from the 10th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2010). The workshop was organized in Leuven, Belgium from 30 November to 3 December 2010 by Katholieke Universiteit Leuven and the imec/Holst Centre. This was a special PowerMEMS Workshop, for several reasons. First of all, we celebrated the 10th anniversary of the workshop: the first PowerMEMS meeting was organized in Sendai, Japan in 2000. None of the organizers or participants of this first meeting could have predicted the impact of the workshop over the next decade. The second reason was that, for the first time, the conference organization spanned two countries: Belgium and the Netherlands. Thanks to the advances in information technology, teams from Katholieke Universiteit Leuven (Belgium) and the imec/Holst Centre in Eindhoven (the Netherlands) have been able to work together seamlessly as one team. The objective of the PowerMEMS Workshop is to stimulate innovation in micro and nanotechnology for power generation and energy conversion applications. Its scope ranges from integrated microelectromechanical systems (MEMS) for power generation, dissipation, harvesting, and management, to novel nanostructures and materials for energy-related applications. True to the objective of the PowerMEMSWorkshop, the 2010 technical program covered a broad range of energy related research, ranging from the nanometer to the millimeter scale, discussed in 5 invited and 52 oral presentations, and 112 posters. This special section includes 14 papers covering vibration energy harvesters, thermal applications and micro power systems. Finally, we wish to express sincere appreciation to the members of the International Steering Committee, the Technical Program Committee and last but not least the Local Organizing Committee. This special issue was edited in

  11. Enhanced arrangement for recuperators in supercritical CO2 Brayton power cycle for energy conversion in fusion reactors

    International Nuclear Information System (INIS)

    Serrano, I.P.; Linares, J.I.; Cantizano, A.; Moratilla, B.Y.

    2014-01-01

    Highlights: •We propose an enhanced power conversion system layout for a Model C fusion reactor. •Proposed layout is based on a modified recompression supercritical CO 2 Brayton cycle. •New arrangement in recuperators regards to classical cycle is used. •High efficiency is achieved, comparable with the best obtained in complex solutions. -- Abstract: A domestic research program called TECNO F US was launched in Spain in 2009 to support technological developments related to a dual coolant breeding blanket concept for fusion reactors. This concept of blanket uses Helium (300 °C/400 °C) to cool part of it and a liquid metal (480 °C/700 °C) to cool the rest; it also includes high temperature (700 °C/800 °C) and medium temperature (566 °C/700 °C) Helium cooling circuits for divertor. This paper proposes a new layout of the classical recompression supercritical CO 2 Brayton cycle which replaces one of the recuperators (the one with the highest temperature) by another which by-passes the low temperature blanket source. This arrangement allows reaching high turbine inlet temperatures (around 600 °C) with medium pressures (around 225 bar) and achieving high cycle efficiencies (close to 46.5%). So, the proposed cycle reveals as a promising design because it integrates all the available thermal sources in a compact layout achieving high efficiencies with the usual parameters prescribed in classical recompression supercritical CO 2 Brayton cycles

  12. Polymer-Polymer Förster Resonance Energy Transfer Significantly Boosts the Power Conversion Efficiency of Bulk-Heterojunction Solar Cells.

    Science.gov (United States)

    Gupta, Vinay; Bharti, Vishal; Kumar, Mahesh; Chand, Suresh; Heeger, Alan J

    2015-08-01

    Optically resonant donor polymers can exploit a wider range of the solar spectrum effectively without a complicated tandem design in an organic solar cell. Ultrafast Förster resonance energy transfer (FRET) in a polymer-polymer system that significantly improves the power conversion efficiency in bulk heterojunction polymer solar cells from 6.8% to 8.9% is demonstrated, thus paving the way to achieving 15% efficient solar cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 2: Materials considerations. [materials used in boilers and heat exchangers of energy conversion systems for electric power plants using coal

    Science.gov (United States)

    Thomas, D. E.

    1976-01-01

    Extensive studies are presented which were carried out on materials behavior in nine advanced energy conversion systems employing coal and coal-derived fuels. The areas of materials behavior receiving particular attention in this regard are: (1) fireside corrosion and erosion in boiler and heat exchanger materials, (2) oxidation and hot corrosion of gas turbine materials, (3) liquid metal corrosion and mass transport, (4) high temperature steam corrosion, (5) compatability of materials with coal slag and MHD seed, (6) reaction of materials with impure helium, (7) allowable stresses for boiler and heat exchanger materials, (8) environmental effects on mechanical properties, and (9) liquid metal purity control and instrumentation. Such information was then utilized in recommending materials for use in the critical components of the power systems, and at the same time to identify materials problem areas and to evaluate qualitatively the difficulty of solving those problems. Specific materials recommendations for critical components of the nine advanced systems under study are contained in summary tables.

  14. OPTIMIZATION OF AEOLIAN ENERGY CONVERSION OPTIMISATION DE LA CONVERSION DE L’ENERGIE EOLIENNE

    Directory of Open Access Journals (Sweden)

    Y. Soufi

    2015-08-01

    Full Text Available The use of renewable energy increases, because people are increasingly concerned with environmental issues. Among renewable, wind power is now widely used. Their study showed that a value of wind speed, there is a maximum mechanical power supplied by the turbine. So, power is supplied are particularly changes with maximum speed.However, the objective of this paper is to present an algorithm for optimal conversion of wind energy based on a criterion optimization that must maintain specific speed of the turbine at optimum speed which corresponds to the maximum power provided by the steady wind turbine. To this end, the object is to preserve the position of any static operating point on the characteristic of optimal.To validate the model and algorithm for optimal conversion of wind energy, a series of numerical simulations carried out using the software MatLab Simulink will be presented is discussed.

  15. Energy conversion using hydrogen PEM fuel cells

    International Nuclear Information System (INIS)

    Stoenescu, D.; Patularu, L.; Culcer, M.; Lazar, R.; Mirica, D.; Varlam, M.; Carcadea, E.; Stefanescu, I.

    2004-01-01

    It is well known that hydrogen is the most promising solution of future energy, both for long and medium term strategies. Hydrogen can be produced using many primary sources (naphthalene, natural gas, methanol, coal, biomass), solar cells power, etc. It can be burned or chemically reacted having a high yield of energy conversion and is a non-polluted fuel. This paper presents the results obtained by ICSI Rm. Valcea in an experimental-demonstrative conversion energy system consisting in a catalytic methane reforming plant for hydrogen production and three synthesis gas purification units in order to get pure hydrogen with a CO level lower than 10 ppm that finally feeds a hydrogen fuel stock. (authors)

  16. Power engineering. Systems for energy conversion. Compact knowledge for study and profession. 4. upd. and enl. ed.; Energietechnik. Systeme zur Energieumwandlung. Kompaktwissen fuer Studium und Beruf

    Energy Technology Data Exchange (ETDEWEB)

    Zahoransky, Richard A.

    2009-07-01

    This textbook imparts to the reader a fundamental understanding for relations of energy conversion processes. It comprises the total spectra of energy engineering, starting with fundamentals of energy process engineering via description of operating power plants (all types) to energy distribution and - storage. Main topics are sustainable energy systems from renewable energy sources. combined systems (e.g. Gas/steam turbine power plants) and plants with cogeneration (e.g. modular cogeneration plants). A new chapter Kyoto-Protocol was created as a concept of emissions-free coal-fired power plants. A new wording for deregulation of energy markets was received. Numerous texts and graphs were been revised. Chapter 18 ''Deregulation of Energy Markets'' is newly revised. Due to its didactic concepts the book directs not only to students but also everybody, who is inerested into actual questions of energy engineering. (org./GL) [German] Dieses Lehrbuch vermittelt dem Leser ein grundlegendes Verstaendnis fuer die Zusammenhaenge der Energieumwandlungsprozesse. Es umfasst die gesamte Bandbreite der Energietechnik. Die Schwerpunkte reichen von nachhaltigen, erneuerbaren Energietechniken, Kombianlagen (z.B. Gas- und Dampfturbinen-Kraftwerke) ueber Anlagen mit Kraft-Waerme-Kaelte-Kopplung bis hin zum Kyoto-Protokoll. Die 4. Auflage beinhaltet erstmals Uebungsaufgaben mit ausfuehrlichen Loesungen zu den einzelnen Kapiteln. Mehrere Kapitel sind aktualisiert. Das Kapitel 18 ''Liberalisierung der Energiemaerkte'' ist neu gefasst. Aus dem Inhalt Energietechnische Grundlagen - Dampfkraftwerke - Kernkraftwerke - Gasturbinen - Kombinationskraftwerke - Stationaere Kolbenmotoren - Brennstoffzellen - Kraft-Waerme-Kaelte-Kopplung - Wasserkraft - Solartechnik - Windenergie - Biomasse - Geothermie - Energetische Muellverwertung - Energieverteilung und -speicherung - Liberalisierung der Energiemaerkte - Kyoto-Protokoll. (orig.)

  17. Particle Discrimination Experiment for Direct Energy Conversion

    International Nuclear Information System (INIS)

    Yasaka, Y.; Kiriyama, Y.; Yamamoto, S.; Takeno, H.; Ishikawa, M.

    2005-01-01

    A direct energy conversion system designed for D- 3 He fusion reactor based on a field reversed configuration employs a venetian-blind type converter for thermal ions to produce DC power and a traveling wave type converter for fusion protons to produce RF power. It is therefore necessary to separate, discriminate, and guide the particle species. For this purpose, a cusp magnetic field is proposed, in which the electrons are deflected and guided along the field line to the line cusp, while the ions pass through the point cusp. A small-scale experimental device was used to study the basic characteristics of discrimination of electrons and ions in the cusp magnetic field. Ions separated from electrons are guided to an ion collector, which is operated as a one-stage direct energy converter. The conversion efficiency was measured for cases with different values of mean and spread of ion energy. These experiments successfully demonstrate direct energy conversion from plasma beams using particle discrimination by a cusp magnetic field

  18. Enhanced arrangement for recuperators in supercritical CO{sub 2} Brayton power cycle for energy conversion in fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, I.P.; Linares, J.I., E-mail: linares@dim.icai.upcomillas.es; Cantizano, A.; Moratilla, B.Y.

    2014-10-15

    Highlights: •We propose an enhanced power conversion system layout for a Model C fusion reactor. •Proposed layout is based on a modified recompression supercritical CO{sub 2} Brayton cycle. •New arrangement in recuperators regards to classical cycle is used. •High efficiency is achieved, comparable with the best obtained in complex solutions. -- Abstract: A domestic research program called TECNO{sub F}US was launched in Spain in 2009 to support technological developments related to a dual coolant breeding blanket concept for fusion reactors. This concept of blanket uses Helium (300 °C/400 °C) to cool part of it and a liquid metal (480 °C/700 °C) to cool the rest; it also includes high temperature (700 °C/800 °C) and medium temperature (566 °C/700 °C) Helium cooling circuits for divertor. This paper proposes a new layout of the classical recompression supercritical CO{sub 2} Brayton cycle which replaces one of the recuperators (the one with the highest temperature) by another which by-passes the low temperature blanket source. This arrangement allows reaching high turbine inlet temperatures (around 600 °C) with medium pressures (around 225 bar) and achieving high cycle efficiencies (close to 46.5%). So, the proposed cycle reveals as a promising design because it integrates all the available thermal sources in a compact layout achieving high efficiencies with the usual parameters prescribed in classical recompression supercritical CO{sub 2} Brayton cycles.

  19. High temperature thermoelectric energy conversion

    International Nuclear Information System (INIS)

    Wood, C.

    1986-01-01

    Considerable advances were made in the late '50's and early early '60's in the theory and development of materials for high-temperature thermoelectric energy conversion. This early work culminated in a variety of materials, spanning a range of temperatures, with the product of the figure of merit, Z, and temperature, T, i.e., the dimensionless figure of merit, ZT, of the order of one. This experimental limitation appeared to be universal and led a number of investigators to explore the possibility that a ZT - also represents a theoretical limitation. It was found not to be so

  20. Energy conversion in polyelectrolyte hydrogels

    Science.gov (United States)

    Olvera de La Cruz, Monica; Erbas, Aykut; Olvera de la Cruz Team

    Energy conversion and storage have been an active field of research in nanotechnology parallel to recent interests towards renewable energy. Polyelectrolyte (PE) hydrogels have attracted considerable attention in this field due to their mechanical flexibility and stimuli-responsive properties. Ideally, when a hydrogel is deformed, applied mechanical work can be converted into electrostatic, elastic and steric-interaction energies. In this talk, we discuss the results of our extensive molecular dynamics simulations of PE hydrogels. We demonstrate that, on deformation, hydrogels adjust their deformed state predominantly by altering electrostatic interactions between their charged groups rather than excluded-volume and bond energies. This is due to the hydrogel's inherent tendency to preserve electro-neutrality in its interior, in combination with correlations imposed by backbone charges. Our findings are valid for a wide range of compression ratios and ionic strengths. The electrostatic-energy alterations that we observe in our MD simulations may induce pH or redox-potential changes inside the hydrogels. The resulting energetic difference can be harvested, for instance, analogously to a Carnot engine, or facilitated for sensor applications. Center for Bio-inspired Energy Science (CBES).

  1. EPR's energy conversion system. Alstom's solutions

    International Nuclear Information System (INIS)

    Ledermann, P.

    2009-01-01

    ARABELLE steam turbines have been developed by Alstom to be used as the energy conversion system of light water reactors with high output power like the N4 PWR and the EPR. ARABELLE turbines cumulate 200.000 hours of service with a reliability ratio of 99.97 per cent. This series of slides presents the main features of the turbine including: the use of the simple flux, the very large shape of low pressure blades, the technology of welded rotors. The other main equipment like the alternator, the condenser, the moisture separator-reheaters, the circulating pumps that Alstom integrates in the energy conversion system have benefited with technological improvements that are also presented. (A.C.)

  2. OPTIMIZATION OF AEOLIAN ENERGY CONVERSION ...

    African Journals Online (AJOL)

    30 juin 2010 ... wind energy based on a criterion optimization that must maintain specific speed of the turbine at optimum speed which corresponds to the maximum power ... ainsi que la structure et les méthodes de contrôle-commande ...

  3. Energy situation and nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Megahid, M R [Reactor and Neutron physics Department Nuclear Research Center A.E., Cairo (Egypt)

    1997-12-31

    A brief general review is given concerning the requirements of power throughout history with an indication to the world capital reserves of energy. The energy released from the conversion of mass in chemical and nuclear processes is also discussed with comparative analysis between conventional fuel fired plant and nuclear power plant having the same energy output. The advantages and disadvantages arising from having a nuclear power programme are also discussed. 1 fig.

  4. Luminescent GdVO_4:Sm"3"+ quantum dots enhance power conversion efficiency of bulk heterojunction polymer solar cells by Förster resonance energy transfer

    International Nuclear Information System (INIS)

    Bishnoi, Swati; Gupta, Vinay; Sharma, Gauri D.; Chand, Suresh; Sharma, Chhavi; Kumar, Mahesh; Haranath, D.; Naqvi, Sheerin

    2016-01-01

    In this work, we report enhanced power conversion efficiency (PCE) of bulk heterojunction polymer solar cells by Förster resonance energy transfer (FRET) from samarium-doped luminescent gadolinium orthovanadate (GdVO_4:Sm"3"+) quantum dots (QDs) to polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7) polymer. The photoluminescence emission spectrum of GdVO_4:Sm"3"+ QDs overlaps with the absorption spectrum of PTB7, leading to FRET from GdVO_4:Sm"3"+ to PTB7, and significant enhancements in the charge-carrier density of excited and polaronic states of PTB7 are observed. This was confirmed by means of femtosecond transient absorption spectroscopy. The FRET from GdVO_4:Sm"3"+ QDs to PTB7 led to a remarkable increase in the power conversion efficiency (PCE) of PTB7:GdVO_4:Sm"3"+:PC_7_1BM ([6,6]-phenyl-C_7_1-butyric acid methyl ester) polymer solar cells. The PCE in optimized ternary blend PTB7:GdVO_4:Sm"3"+:PC_7_1BM (1:0.1:1.5) is increased to 8.8% from 7.2% in PTB7:PC_7_1BM. This work demonstrates the potential of rare-earth based luminescent QDs in enhancing the PCE of polymer solar cells.

  5. Research on spacecraft electrical power conversion

    Science.gov (United States)

    Wilson, T. G.

    1983-01-01

    The history of spacecraft electrical power conversion in literature, research and practice is reviewed. It is noted that the design techniques, analyses and understanding which were developed make today's contribution to power computers and communication installations. New applications which require more power, improved dynamic response, greater reliability, and lower cost are outlined. The switching mode approach in electronic power conditioning is discussed. Technical aspects of the research are summarized.

  6. Renewable energy systems advanced conversion technologies and applications

    CERN Document Server

    Luo, Fang Lin

    2012-01-01

    Energy conversion techniques are key in power electronics and even more so in renewable energy source systems, which require a large number of converters. Renewable Energy Systems: Advanced Conversion Technologies and Applications describes advanced conversion technologies and provides design examples of converters and inverters for renewable energy systems-including wind turbine and solar panel energy systems. Learn Cutting-Edge Techniques for Converters and Inverters Setting the scene, the book begins with a review of the basics of astronomy and Earth physics. It then systematically introduc

  7. Selected papers from the 12th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2012) (Atlanta, GA, USA, 2-5 December 2012)

    Science.gov (United States)

    Allen, Mark G.; Lang, Jeffrey

    2013-11-01

    Welcome to this special section of the Journal of Micromechanics and Microengineering (JMM). This section, co-edited by myself and by Professor Jeffrey Lang of the Massachusetts Institute of Technology, contains expanded versions of selected papers presented at the Power MEMS meeting held in Atlanta, GA, USA, in December of 2012. Professor Lang and I had the privilege of co-chairing Power MEMS 2012, the 12th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications. The scope of the PowerMEMS series of workshops ranges from basic principles, to materials and fabrication, to devices and systems, to applications. The many applications of power MEMS (microelectromehcanical systems) range from MEMS-enabled energy harvesting, storage, conversion and conditioning, to integrated systems that manage these processes. Why is the power MEMS field growing in importance? Smaller-scale power and power supplies (microwatts to tens of watts) are gaining in prominence due to many factors, including the ubiquity of low power portable electronic equipment and the proliferation of wireless sensor nodes that require extraction of energy from their embedding environment in order to function. MEMS manufacturing methods can be utilized to improve the performance of traditional power supply elements, such as allowing batteries to charge faster or shrinking the physical size of passive elements in small-scale power supplies. MEMS technologies can be used to fabricate energy harvesters that extract energy from an embedding environment to power wireless sensor nodes, in-body medical implants and other devices, in which the harvesters are on the small scales that are appropriately matched to the overall size of these microsystems. MEMS can enable the manufacturing of energy storage elements from nontraditional materials by bringing appropriate structure and surface morphology to these materials as well as fabricating the electrical interfaces

  8. Carbon aerogel electrodes for direct energy conversion

    Science.gov (United States)

    Mayer, Steven T.; Kaschmitter, James L.; Pekala, Richard W.

    1997-01-01

    A direct energy conversion device, such as a fuel cell, using carbon aerogel electrodes, wherein the carbon aerogel is loaded with a noble catalyst, such as platinum or rhodium and soaked with phosphoric acid, for example. A separator is located between the electrodes, which are placed in a cylinder having plate current collectors positioned adjacent the electrodes and connected to a power supply, and a pair of gas manifolds, containing hydrogen and oxygen positioned adjacent the current collectors. Due to the high surface area and excellent electrical conductivity of carbon aerogels, the problems relative to high polarization resistance of carbon composite electrodes conventionally used in fuel cells are overcome.

  9. Tropospheric effects of energy conversion

    International Nuclear Information System (INIS)

    Derwent, R.G.

    1992-01-01

    The tropospheric concentrations of a number of trace gases are increasing due to man's activities. For some trace gases, their atmospheric life cycles are not fully understood and it is difficult to be certain about the role of man's activities. Emissions from the energy industries and energy conversion processes represent an important subset of source terms in these life cycles, along with agriculture, deforestation, cement manufacture, biomass burning, process industries and natural biospheric processes. Global Warming Potentials (GWPs) allow the tropospheric effects of a range of climate forcing trace gases to be assessed on a comparable basis. If a short term view of the commitment to global warming is adopted then the contribution from other trace gases may approach and exceed that of carbon dioxide, itself. Over longer time horizons, the long atmospheric lifetime of carbon dioxide shows through as a major influence and the contributions from the other trace gases appear to be much smaller, representing an additional 13-18% contribution on top of that from CO 2 itself

  10. Thermoelectric Energy Conversion: Materials, Devices, and Systems

    International Nuclear Information System (INIS)

    Chen, Gang

    2015-01-01

    This paper will present a discussion of challenges, progresses, and opportunities in thermoelectric energy conversion technology. We will start with an introduction to thermoelectric technology, followed by discussing advances in thermoelectric materials, devices, and systems. Thermoelectric energy conversion exploits the Seebeck effect to convert thermal energy into electricity, or the Peltier effect for heat pumping applications. Thermoelectric devices are scalable, capable of generating power from nano Watts to mega Watts. One key issue is to improve materials thermoelectric figure- of-merit that is linearly proportional to the Seebeck coefficient, the square of the electrical conductivity, and inversely proportional to the thermal conductivity. Improving the figure-of-merit requires good understanding of electron and phonon transport as their properties are often contradictory in trends. Over the past decade, excellent progresses have been made in the understanding of electron and phonon transport in thermoelectric materials, and in improving existing and identify new materials, especially by exploring nanoscale size effects. Taking materials to real world applications, however, faces more challenges in terms of materials stability, device fabrication, thermal management and system design. Progresses and lessons learnt from our effort in fabricating thermoelectric devices will be discussed. We have demonstrated device thermal-to-electrical energy conversion efficiency ∼10% and solar-thermoelectric generator efficiency at 4.6% without optical concentration of sunlight (Figure 1) and ∼8-9% efficiency with optical concentration. Great opportunities exist in advancing materials as well as in using existing materials for energy efficiency improvements and renewable energy utilization, as well as mobile applications. (paper)

  11. Expansionary economic effects of energy conversion under stagnation

    International Nuclear Information System (INIS)

    Ono, Yoshiyasu

    2013-01-01

    After the Fukushima disaster, energy conversion such as nuclear power phaseout and deployment of renewable energy or survival of nuclear power had been actively argued pro and con. Both sides admitted extra costs were needed but their economic effects would be contrary dependent on business state. Under better economy, extra costs would be actual burden of total economy. Under stagnation as was long in Japan at present, extra costs brought about expansion of employment and economy with simulated consumption increase. Industry conversion would occur such industry intensively using power would depreciate and energy conserved industry would grow. Difference of power use intensity between industries made difficult in energy conversion because present Japanese industry constitution was mostly formed based on cheap power cost for industry use. Even taking account of international competition, the same would be true by adjusting finance balance sheet and currency exchange rate. (T. Tanaka)

  12. Fundamental formulae for wave-energy conversion.

    Science.gov (United States)

    Falnes, Johannes; Kurniawan, Adi

    2015-03-01

    The time-average wave power that is absorbed from an incident wave by means of a wave-energy conversion (WEC) unit, or by an array of WEC units-i.e. oscillating immersed bodies and/or oscillating water columns (OWCs)-may be mathematically expressed in terms of the WEC units' complex oscillation amplitudes, or in terms of the generated outgoing (diffracted plus radiated) waves, or alternatively, in terms of the radiated waves alone. Following recent controversy, the corresponding three optional expressions are derived, compared and discussed in this paper. They all provide the correct time-average absorbed power. However, only the first-mentioned expression is applicable to quantify the instantaneous absorbed wave power and the associated reactive power. In this connection, new formulae are derived that relate the 'added-mass' matrix, as well as a couple of additional reactive radiation-parameter matrices, to the difference between kinetic energy and potential energy in the water surrounding the immersed oscillating WEC array. Further, a complex collective oscillation amplitude is introduced, which makes it possible to derive, by a very simple algebraic method, various simple expressions for the maximum time-average wave power that may be absorbed by the WEC array. The real-valued time-average absorbed power is illustrated as an axisymmetric paraboloid defined on the complex collective-amplitude plane. This is a simple illustration of the so-called 'fundamental theorem for wave power'. Finally, the paper also presents a new derivation that extends a recently published result on the direction-average maximum absorbed wave power to cases where the WEC array's radiation damping matrix may be singular and where the WEC array may contain OWCs in addition to oscillating bodies.

  13. NASA-OAST program in photovoltaic energy conversion

    Science.gov (United States)

    Mullin, J. P.; Flood, D. J.

    1982-01-01

    The NASA program in photovoltaic energy conversion includes research and technology development efforts on solar cells, blankets, and arrays. The overall objectives are to increase conversion efficiency, reduce mass, reduce cost, and increase operating life. The potential growth of space power requirements in the future presents a major challenge to the current state of technology in space photovoltaic systems.

  14. Real-Time Control of Active and Reactive Power for Doubly Fed Induction Generator (DFIG-Based Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Aman Abdulla Tanvir

    2015-09-01

    Full Text Available This paper presents the modeling, rapid control prototyping, and hardware-in-the-loop testing for real-time simulation and control of a grid-connected doubly fed induction generator (DFIG in a laboratory-size wind turbine emulator for wind energy conversation systems. The generator is modeled using the direct-quadrature rotating reference frame circuit along with the aligned stator flux, and the field-oriented control approach is applied for independent control of the active and reactive power and the DC-link voltage at the grid side. The control of the active, reactive power and the DC-link voltage are performed using a back-to-back converter at sub- and super-synchronous as well as at variable speeds. The control strategy is experimentally validated on an emulated wind turbine driven by the Opal-RT real-time simulator (OP5600 for simultaneous control of the DC-link voltage, active and reactive power.

  15. Biomass energy conversion: conventional and advanced technologies

    Energy Technology Data Exchange (ETDEWEB)

    Young, B C; Hauserman, W B [Energy and Environmental Research Center, University of North Dakota, Grand Forks, ND (United States)

    1995-12-01

    Increasing interest in biomass energy conversion in recent years has focused attention on enhancing the efficiency of technologies converting biomass fuels into heat and power, their capital and operating costs and their environmental emissions. Conventional combustion systems, such as fixed-bed or grate units and entrainment units, deliver lower efficiencies (<25%) than modem coal-fired combustors (30-35%). The gasification of biomass will improve energy conversion efficiency and yield products useful for heat and power generation and chemical synthesis. Advanced biomass gasification technologies using pressurized fluidized-bed systems, including those incorporating hot-gas clean-up for feeding gas turbines or fuel cells, are being demonstrated. However, many biomass gasification processes are derivatives of coal gasification technologies and do not exploit the unique properties of biomass. This paper examines some existing and upcoming technologies for converting biomass into electric power or heat. Small-scale 1-30 MWe units are emphasized, but brief reference is made to larger and smaller systems, including those that bum coal-biomass mixtures and gasifiers that feed pilot-fuelled diesel engines. Promising advanced systems, such as a biomass integrated gasifier/gas turbine (BIG/GT) with combined-cycle operation and a biomass gasifier coupled to a fuel cell, giving cycle efficiencies approaching 50% are also described. These advanced gasifiers, typically fluid-bed designs, may be pressurized and can use a wide variety of biomass materials to generate electricity, process steam and chemical products such as methanol. Low-cost, disposable catalysts are becoming available for hot-gas clean-up (enhanced gas composition) for turbine and fuel cell systems. The advantages, limitations and relative costs of various biomass gasifier systems are briefly discussed. The paper identifies the best known biomass power projects and includes some information on proposed and

  16. Biomass energy conversion: conventional and advanced technologies

    International Nuclear Information System (INIS)

    Young, B.C.; Hauserman, W.B.

    1995-01-01

    Increasing interest in biomass energy conversion in recent years has focused attention on enhancing the efficiency of technologies converting biomass fuels into heat and power, their capital and operating costs and their environmental emissions. Conventional combustion systems, such as fixed-bed or grate units and entrainment units, deliver lower efficiencies (<25%) than modem coal-fired combustors (30-35%). The gasification of biomass will improve energy conversion efficiency and yield products useful for heat and power generation and chemical synthesis. Advanced biomass gasification technologies using pressurized fluidized-bed systems, including those incorporating hot-gas clean-up for feeding gas turbines or fuel cells, are being demonstrated. However, many biomass gasification processes are derivatives of coal gasification technologies and do not exploit the unique properties of biomass. This paper examines some existing and upcoming technologies for converting biomass into electric power or heat. Small-scale 1-30 MWe units are emphasized, but brief reference is made to larger and smaller systems, including those that bum coal-biomass mixtures and gasifiers that feed pilot-fuelled diesel engines. Promising advanced systems, such as a biomass integrated gasifier/gas turbine (BIG/GT) with combined-cycle operation and a biomass gasifier coupled to a fuel cell, giving cycle efficiencies approaching 50% are also described. These advanced gasifiers, typically fluid-bed designs, may be pressurized and can use a wide variety of biomass materials to generate electricity, process steam and chemical products such as methanol. Low-cost, disposable catalysts are becoming available for hot-gas clean-up (enhanced gas composition) for turbine and fuel cell systems. The advantages, limitations and relative costs of various biomass gasifier systems are briefly discussed. The paper identifies the best known biomass power projects and includes some information on proposed and

  17. A Flexible, Stretchable and Shape-Adaptive Approach for Versatile Energy Conversion and Self-Powered Biomedical Monitoring

    KAUST Repository

    Yang, Po Kang; Lin, Long; Yi, Fang; Li, Xiuhan; Pradel, Ken C.; Zi, Yunlong; Wu, Chih I.; He, Jr-Hau; Zhang, Yue; Wang, Zhong Lin

    2015-01-01

    A flexible triboelectric nanogenerator (FTENG) based on wavy-structured Kapton film and a serpentine electrode on stretchable substrates is presented. The as-fabricated FTENG is capable of harvesting ambient mechanical energy via both compressive

  18. Experimental Research of a New Wave Energy Conversion Device

    Science.gov (United States)

    Lu, Zhongyue; Shang, Jianzhong; Luo, Zirong; Sun, Chongfei; Chen, Gewei

    2018-01-01

    With the increasing tension of contemporary social energy, the development and utilization of renewable energy has become an important development direction. As an important part of renewable energy, wave energy has the characteristics of green environmental protection and abundant reserves, attracting more investment and research. For small marine equipment energy supply problem, this paper puts forward a micro wave energy conversion device as the basic of heaving motion of waves in the ocean. This paper designed a new type of power output device can solve the micro wave energy conversion problem.

  19. Energy Storage System with Voltage Equalization Strategy for Wind Energy Conversion

    Directory of Open Access Journals (Sweden)

    Cheng-Tao Tsai

    2012-07-01

    Full Text Available In this paper, an energy storage system with voltage equalization strategy for wind energy conversion is presented. The proposed energy storage system provides a voltage equalization strategy for series-connected lead-acid batteries to increase their total storage capacity and lifecycle. In order to draw the maximum power from the wind energy, a perturbation-and-observation method and digital signal processor (DSP are incorporated to implement maximum power point tracking (MPPT algorithm and power regulating scheme. In the proposed energy storage system, all power switches have zero-voltage-switching (ZVS feature at turn-on transition. Therefore, the conversion efficiency can be increased. Finally, a prototype energy storage system for wind energy conversion is built and implemented. Experimental results have verified the performance and feasibility of the proposed energy storage system for wind energy conversion.

  20. Thermodynamic analysis and comparison between CO_2 transcritical power cycles and R245fa organic Rankine cycles for low grade heat to power energy conversion

    International Nuclear Information System (INIS)

    Li, L.; Ge, Y.T.; Luo, X.; Tassou, S.A.

    2016-01-01

    Highlights: • CO_2 is a promising working fluid to be applied in low-grade power generation systems. • Thermodynamic models of CO_2 transcritical power cycles (T-CO_2) and R245fa ORC were developed. • Energy and exergy analyses were carried out for T-CO_2 and R245fa ORC systems. • Optimal system designs are existed for both T-CO_2 and R245fa ORC systems. - Abstract: In this paper, a theoretical study is conducted to investigate and compare the performance of CO_2 transcritical power cycles (T-CO_2) and R245fa organic Rankine cycles (ORCs) using low-grade thermal energy to produce useful shaft or electrical power. Each power cycle consists of typical Rankine cycle components, such as a working fluid pump, gas generator or evaporator, turbine with electricity generator, air cooled condenser and recuperator (internal heat exchanger). The thermodynamic models of both cycles have been developed and are applied to calculate and compare the cycle thermal and exergy efficiencies at different operating conditions and control strategies. The simulation results show that the system performances for both cycles vary with different operating conditions. When the heat source (waste heat) temperature increases from 120 °C to 260 °C and heat sink (cooling air) temperature is reduced from 20 °C to 0 °C, both thermal efficiencies of R245fa ORC and T-CO_2 with recuperator can significantly increase. On the other hand, R245fa ORC and T-CO_2 exergy efficiencies increase with lower heat sink temperatures and generally decrease with higher heat source temperatures. In addition, with the same operating conditions and heat transfer assumptions, the thermal and exergy efficiencies of R245fa ORCs are both slightly higher than those of T-CO_2. However, the efficiencies of both cycles can be enhanced by installing a recuperator in each system at specified operating conditions. Ultimately, optimal operating states can be predicted, with particular focus on the working fluid expander

  1. Electrical Systems for Wave Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Bostroem, Cecilia

    2011-07-01

    Wave energy is a renewable energy source with a large potential to contribute to the world's electricity production. There exist several technologies on how to convert the energy in the ocean waves into electric energy. The wave energy converter (WEC) presented in this thesis is based on a linear synchronous generator. The generator is placed on the seabed and driven by a point absorbing buoy on the ocean surface. Instead of having one large unit, several smaller units are interconnected to increase the total installed power. To convert and interconnect the power from the generators, marine substations are used. The marine substations are placed on the seabed and convert the fluctuating AC from the generators into an AC suitable for grid connection. The work presented in the thesis focuses on the first steps in the electric energy conversion, converting the voltage out from the generators into DC, which have an impact on the WEC's ability to absorb and produce power. The purpose has been to investigate how the generator will operate when it is subjected to different load cases and to obtain guidelines on how future systems could be improved. Offshore experiments and simulations have been done on full scale generators connected to four different loads, i.e. one linear resistive load and three different non-linear loads representing different cases for grid connected WECs. The results show that the power can be controlled and optimized by choosing a suitable system for the WEC. It is not obvious which kind of system is the most preferable, since there are many different parameters that have an impact on the system performance, such as the size of the buoy, how the generator is designed, the number of WECs, the highest allowed complexity of the system, costs and so on. Therefore, the design of the electrical system should preferably be carried out in parallel with the design of the WEC in order to achieve an efficient system

  2. Electrophoretic-deposited CNT/MnO2 composites for high-power electrochemical energy storage/conversion applications

    Science.gov (United States)

    Xiao, Wei; Xia, Hui; Fuh, Jerry Y. H.; Lu, Li

    2010-05-01

    CNT/MnO2 (birnessite-type) composite films have been successfully deposited on Ni-foil substrate via electrophoretic deposition (EPD). The unique EPD CNT/MnO2 composite film electrode shows enhanced electrical conductivity, good contact between composite films and the substrate and open porous structure, which makes the EPD composite films a promising electrode for high-power supercapacitors and lithium ion batteries.

  3. Electrophoretic-deposited CNT/MnO{sub 2} composites for high-power electrochemical energy storage/conversion applications

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Wei; Xia Hui; Fuh, Jerry Y H; Lu Li, E-mail: luli@nus.edu.s [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore)

    2010-05-01

    CNT/MnO{sub 2} (birnessite-type) composite films have been successfully deposited on Ni-foil substrate via electrophoretic deposition (EPD). The unique EPD CNT/MnO{sub 2} composite film electrode shows enhanced electrical conductivity, good contact between composite films and the substrate and open porous structure, which makes the EPD composite films a promising electrode for high-power supercapacitors and lithium ion batteries.

  4. Ballistic energy conversion: physical modeling and optical characterization

    NARCIS (Netherlands)

    Xie, Yanbo; Bos, Diederik; van der Meulen, Mark-Jan; van der Meulen, Mark-Jan; Versluis, Michel; van den Berg, Albert; Eijkel, Jan C.T.

    2016-01-01

    The growing demand for renewable energy stimulates the exploration of new materials and methods for clean energy, a process which is boosted by nanoscience and emerging nanotechnologies. Recently a high efficiency and high power density energy conversion mechanism was demonstrated through the use of

  5. Advances in wind energy conversion technology

    CERN Document Server

    Sathyajith, Mathew

    2011-01-01

    The technology of generating energy from wind has significantly changed during the past five years. The book brings together all the latest aspects of wind energy conversion technology - from wind resource analysis to grid integration of generated electricity.

  6. Ocean thermal energy conversion (OTEC) power system development (PSD) II. Preliminary design report. Appendix II: supporting data

    Energy Technology Data Exchange (ETDEWEB)

    1979-08-10

    The trade studies, calculations, and reports which provide the rationale for design conclusions for the 10 MWe OTEC power system are presented in this volume. These appendices include: (1) system design and optimization model; (2) system off-design performance computer model; (3) seawater system dynamics; (4) system mechanical design studies; (5) electrical design studies; (6) structural design studies; (7) tube cleaner design report and proposed brush test program; (8) heat exchangers: mechanical design; (9) heat exchangers: thermal hydraulic computer model; (10) heat exchangers: manufacturing flow plan; (11) heat exchangers: installation and removal procedures; (12) heat exchangers: stainless steel conceptual design; (13) heat exchangers: cost studies; (14)heat exchangers: materials selection and corrosion; and (15) heat exchangers: quality assurance. (WHK)

  7. Renewable energies for power generation

    International Nuclear Information System (INIS)

    Freris, L.; Infield, D.

    2009-01-01

    Power generation from renewable energy sources is different from power generation from classical energies (nuclear, thermal..). Therefore, the integration into the grid of the electricity supplied by renewable sources requires a deep thinking. The reason is that these power sources are controlled by variable elements, like wind, water and sun, which condition production. This book deals with the following aspects in detail: characteristics of classical and intermittent generators; grid balancing between supply and demand; conversion methods of renewable energies into electricity; power systems; privatizing of power generation and birth of new markets, in particular the 'green' power market; development of renewable energies thanks to technical advances. It gives a comprehensive overview of the present day available renewable energy sources for power generation. (J.S.)

  8. Energy conversion by ‘T-shaped’ cantilever type electromagnetic vibration based micro power generator from low frequency vibration sources

    International Nuclear Information System (INIS)

    Siddique, Abu Raihan Mohammad; Mahmud, Shohel; Van Heyst, Bill

    2017-01-01

    Highlights: • A T-shaped cantilever type electromagnetic vibration based MPG has been described. • The designed EVMPG is useful for low frequency based vibration sources. • Both experimental tests and theoretical analysis have been performed. • The final compact prototype was tested at different conditions of human movements. • The prototype can generate 35.2 mV and 0.22 mW at 7 Hz with 5.6 Ω. - Abstract: The design, development, and analyses of low-frequency vibration based T-shaped cantilever type electromagnetic micro power generators (EVMPGs) are presented in this paper. Four different configurations (Configurations A to D) of EVMPGs were designed and fabricated and subsequently characterized using detailed experimental and limited analytical techniques. Configuration A and B consisted of a single and a double cylindrical moving magnets (NdFeB), respectively, while Configuration C consisted of four rectangular moving magnets with respect to a fixed copper coil. In contrast, Configuration D used a moving coil between four rectangular magnets with a back-iron bar. The open circuit RMS voltage output was observed to be a maximum from Configuration D (98.2 mV at 6.29 Hz) with a base vibration acceleration of 0.8 m s"−"2. Therefore, Configuration D was selected for further experimental investigations, which included changing the back-iron bar thickness, changing the base acceleration level, and changing the air gap separation between the magnets in order to optimize this configuration. The maximum load RMS voltage and power outputs of Configuration D were 105.4 mV and 1.35 mW at 6.29 Hz for load resistance 8.2 Ω and a base acceleration of 0.8 m s"−"2 with a 4.2 mm back-iron bar when the air gap between the magnets was 20 mm. Finally, a small portable EVMPG prototype was developed based on the Configuration D and was tested at different human movement conditions (i.e., walking, quick walking, and running). The developed EVMPG prototype was capable of

  9. Technology assessment of wind energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Meier, B. W.; Merson, T. J.

    1980-09-01

    Environmental data for wind energy conversion systems (WECSs) have been generated in support of the Technology Assessment of Solar Energy (TASE) program. Two candidates have been chosen to characterize the WECS that might be deployed if this technology makes a significant contribution to the national energy requirements. One WECS is a large machine of 1.5-MW-rated capacity that can be used by utilities. The other WECS is a small machine that is characteristic of units that might be used to meet residential or small business energy requirements. Energy storage systems are discussed for each machine to address the intermittent nature of wind power. Many types of WECSs are being studied and a brief review of the technology is included to give background for choosing horizontal axis designs for this study. Cost estimates have been made for both large and small systems as required for input to the Strategic Environmental Assessment Simulation (SEAS) computer program. Material requirements, based on current generation WECSs, are discussed and a general discussion of environmental impacts associated with WECS deployment is presented.

  10. In silico designing of power conversion efficient organic lead dyes for solar cells using todays innovative approaches to assure renewable energy for future

    Science.gov (United States)

    Kar, Supratik; Roy, Juganta K.; Leszczynski, Jerzy

    2017-06-01

    Advances in solar cell technology require designing of new organic dye sensitizers for dye-sensitized solar cells with high power conversion efficiency to circumvent the disadvantages of silicon-based solar cells. In silico studies including quantitative structure-property relationship analysis combined with quantum chemical analysis were employed to understand the primary electron transfer mechanism and photo-physical properties of 273 arylamine organic dyes from 11 diverse chemical families explicit to iodine electrolyte. The direct quantitative structure-property relationship models enable identification of the essential electronic and structural attributes necessary for quantifying the molecular prerequisites of 11 classes of arylamine organic dyes, responsible for high power conversion efficiency of dye-sensitized solar cells. Tetrahydroquinoline, N,N'-dialkylaniline and indoline have been least explored classes under arylamine organic dyes for dye-sensitized solar cells. Therefore, the identified properties from the corresponding quantitative structure-property relationship models of the mentioned classes were employed in designing of "lead dyes". Followed by, a series of electrochemical and photo-physical parameters were computed for designed dyes to check the required variables for electron flow of dye-sensitized solar cells. The combined computational techniques yielded seven promising lead dyes each for all three chemical classes considered. Significant (130, 183, and 46%) increment in predicted %power conversion efficiency was observed comparing with the existing dye with highest experimental %power conversion efficiency value for tetrahydroquinoline, N,N'-dialkylaniline and indoline, respectively maintaining required electrochemical parameters.

  11. Direct Energy Conversion Literature Abstracts

    Science.gov (United States)

    1962-12-01

    TMMOELECTRIC 6 CONVERSION SYSTEMS. compiled by Edda 7p.. Aug.1960. (Spec. Bibl. 430) Barber. 48p., Mar. 1962. (Lit. Search 392) (Contract NAS 7-100) Covers...2865 BaranskiiP.I ............... 2905, 2945 Brogan, T.R. .............. 3322 Barber, Edda ................. . 2866 Brooklyn Polytechnic

  12. Semiconductor nanowires for photovoltaic and photoelectrochemical energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Neil; Yang, Peidong

    2013-01-23

    Semiconductor nanowires (NW) possess several beneficial properties for efficient conversion of solar energy into electricity and chemical energy. Due to their efficient absorption of light, short distances for minority carriers to travel, high surface-to-volume ratios, and the availability of scalable synthesis methods, they provide a pathway to address the low cost-to-power requirements for wide-scale adaptation of solar energy conversion technologies. Here we highlight recent progress in our group towards implementation of NW components as photovoltaic and photoelectrochemical energy conversion devices. An emphasis is placed on the unique properties of these one-dimensional (1D) structures, which enable the use of abundant, low-cost materials and improved energy conversion efficiency compared to bulk devices.

  13. Materials in energy conversion, harvesting, and storage

    CERN Document Server

    Lu, Kathy

    2014-01-01

    First authored book to address materials' role in the quest for the next generation of energy materials Energy balance, efficiency, sustainability, and so on, are some of many facets of energy challenges covered in current research. However, there has not been a monograph that directly covers a spectrum of materials issues in the context of energy conversion, harvesting and storage. Addressing one of the most pressing problems of our time, Materials in Energy Conversion, Harvesting, and Storage illuminates the roles and performance requirements of materials in energy an

  14. Energy, electricity and nuclear power

    International Nuclear Information System (INIS)

    Reuss, P.; Naudet, G.

    2008-01-01

    After an introduction recalling what energy is, the first part of this book presents the present day energy production and consumption and details more particularly the electricity 'vector' which is an almost perfect form of energy despite the fact that it is not a primary energy source: it must be generated from another energy source and no large scale storage of this energy is possible. The second part of the book is devoted to nuclear energy principles and to the related technologies. Content: 1 - What does energy mean?: the occurrence of the energy concept, the classical notion of energy, energy notion in modern physics, energy transformations, energy conservation, irreversibility of energy transformations, data and units used in the energy domain; 2 - energy production and consumption: energy systems, energy counting, reserves and potentialities of energy resources, production of primary energies, transport and storage of primary energies, energy consumption, energy saving, energy markets and prices, energy indicators; 3 - electric power: specificity of electricity and the electric system, power networks, power generation, electricity storage, power consumption and demand, power generation economics, electricity prices and market; 4 - physical principles of nuclear energy: nuclei structure and binding energy, radioactivity and nuclear reactions, nuclear reactions used in energy generation, basics of fission reactors physics; 5 - nuclear techniques: historical overview, main reactor types used today, perspectives; 6 - fuel cycle: general considerations, uranium mining, conversion, enrichment, fuel fabrication, back-end of the cycle, plutonium recycle in water cooled reactors; 7 - health and environmental aspects of nuclear energy: effects on ionizing radiations, basics of radiation protection, environmental impacts of nuclear energy, the nuclear wastes problem, specific risks; 8 - conclusion; 9 - appendixes (units, physics constants etc..)

  15. Comparative Evaluation of Phase 1 Results from the Energy Conversion Alternatives Study (ECAS). [coal utilization for electric power plants feasibility analysis

    Science.gov (United States)

    1976-01-01

    Ten advanced energy conversion systems for central-station, based-load electric power generation using coal and coal-derived fuels which were studied by NASA are presented. Various contractors were selected by competitive bidding to study these systems. A comparative evaluation is provided of the contractor results on both a system-by-system and an overall basis. Ground rules specified by NASA, such as coal specifications, fuel costs, labor costs, method of cost comparison, escalation and interest during construction, fixed charges, emission standards, and environmental conditions, are presented. Each system discussion includes the potential advantages of the system, the scope of each contractor's analysis, typical schematics of systems, comparison of cost of electricity and efficiency for each contractor, identification and reconciliation of differences, identification of future improvements, and discussion of outside comments. Considerations common to all systems, such as materials and furnaces, are also discussed. Results of selected in-house analyses are presented, in addition to contractor data. The results for all systems are then compared.

  16. Entropy fluxes, endoreversibility, and solar energy conversion

    Science.gov (United States)

    de Vos, A.; Landsberg, P. T.; Baruch, P.; Parrott, J. E.

    1993-09-01

    A formalism illustrating the conversion of radiation energy into work can be obtained in terms of energy and entropy fluxes. Whereas the Landsberg equality was derived for photothermal conversion with zero bandgap, a generalized inequality for photothermal/photovoltaic conversion with a single, but arbitrary, bandgap was deduced. This result was derived for a direct energy and entropy balance. The formalism of endoreversible dynamics was adopted in order to show the correlation with the latter approach. It was a surprising fact that the generalized Landsberg inequality was derived by optimizing some quantity W(sup *), which obtains it maximum value under short-circuit condition.

  17. Energy Conversion & Storage Program, 1993 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, E.J.

    1994-06-01

    The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in: production of new synthetic fuels; development of high-performance rechargeable batteries and fuel cells; development of high-efficiency thermochemical processes for energy conversion; characterization of complex chemical processes and chemical species; and the study and application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis.

  18. Effect of Short-Circuit Faults in the Back-to-Back Power Electronic Converter and Rotor Terminals on the Operational Behavior of the Doubly-Fed Induction Generator Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Dimitrios G. Giaourakis

    2015-02-01

    Full Text Available This paper deals with the operational behavior of the Doubly-Fed Induction Generator Wind Energy Conversion System under power electronic converter and rotor terminals faulty conditions. More specifically, the effect of the short-circuit fault both in one IGBT of the back-to-back power electronic converter and in rotor phases on the overall system behavior has been investigated via simulation using a system of 2 MW. Finally, the consequences of these faults have been evaluated.

  19. Designing Energy Conversion Systems for the Next Decade

    Directory of Open Access Journals (Sweden)

    Slobodan N. Vukosavić

    2012-12-01

    Full Text Available Sustainable growth in energy consumption requires transition to clean and green energy sources and energy systems. Environment friendly and renewable energy systems deal with electrical energy and rely on efficient electrical power converters. High power electronics is the key technology to deal with the next generation of electrical energy systems. The door to future breakthroughs in high power electronics is opened by major improvement in semiconductor power devices and their packaging technologies. New materials allow for much higher junction temperatures and higher operating voltages. Most importantly, advanced power semiconductor devices and novel converter topology open the possibility to increase the energy efficiency of power conversion and reduce the amount of heat. Although the waste heat created by high power converters can be put to use by adding on to heating systems, this option is not always available and the conversion losses are mostly wasted. At the same time, wasted heat is a form of pollution that threatens the environment. Another task for high power converters is efficient harvesting of renewable energy sources, such as the wind energy and the sun. Intermittent in nature, they pose a difficult task to power converter topology and controls. Eventually, high power converters are entering power distribution and transmission networks. With their quick reaction, with fast communication between the grid nodes and with advanced controllability of high power converters, a number of innovations can be introduced, facilitating the power system control and allowing for optimizations and loss reduction. Coined smart grid, this solution comprises two key elements, and these are intelligent controls and large static power converters. At virtually no cost, smart grids allow for a better utilization of available resources and it enlarges the stable operating range of the transmission systems. Therefore, it is of interest to review the

  20. Urban energy conversion and its effects

    International Nuclear Information System (INIS)

    Geiger, B.

    1981-01-01

    The extent to which the building up and energy conversion affect the quality and energy economy of living space is shown by the example of Munich. The comparison of the energy economy of various ecological systems give qualified information for assessing the thermal loading in densely inhabited areas and show the basic differences between built-up and country areas. (DG) [de

  1. Physical Limits of Solar Energy Conversion in the Earth System.

    Science.gov (United States)

    Kleidon, Axel; Miller, Lee; Gans, Fabian

    2016-01-01

    Solar energy provides by far the greatest potential for energy generation among all forms of renewable energy. Yet, just as for any form of energy conversion, it is subject to physical limits. Here we review the physical limits that determine how much energy can potentially be generated out of sunlight using a combination of thermodynamics and observed climatic variables. We first explain how the first and second law of thermodynamics constrain energy conversions and thereby the generation of renewable energy, and how this applies to the conversions of solar radiation within the Earth system. These limits are applied to the conversion of direct and diffuse solar radiation - which relates to concentrated solar power (CSP) and photovoltaic (PV) technologies as well as biomass production or any other photochemical conversion - as well as solar radiative heating, which generates atmospheric motion and thus relates to wind power technologies. When these conversion limits are applied to observed data sets of solar radiation at the land surface, it is estimated that direct concentrated solar power has a potential on land of up to 11.6 PW (1 PW=10(15) W), whereas photovoltaic power has a potential of up to 16.3 PW. Both biomass and wind power operate at much lower efficiencies, so their potentials of about 0.3 and 0.1 PW are much lower. These estimates are considerably lower than the incoming flux of solar radiation of 175 PW. When compared to a 2012 primary energy demand of 17 TW, the most direct uses of solar radiation, e.g., by CSP or PV, have thus by far the greatest potential to yield renewable energy requiring the least space to satisfy the human energy demand. Further conversions into solar-based fuels would be reduced by further losses which would lower these potentials. The substantially greater potential of solar-based renewable energy compared to other forms of renewable energy simply reflects much fewer and lower unavoidable conversion losses when solar

  2. Electromagnetic wave energy conversion research

    Science.gov (United States)

    Bailey, R. L.; Callahan, P. S.

    1975-01-01

    Known electromagnetic wave absorbing structures found in nature were first studied for clues of how one might later design large area man-made radiant-electric converters. This led to the study of the electro-optics of insect dielectric antennae. Insights were achieved into how these antennae probably operate in the infrared 7-14um range. EWEC theoretical models and relevant cases were concisely formulated and justified for metal and dielectric absorber materials. Finding the electromagnetic field solutions to these models is a problem not yet solved. A rough estimate of losses in metal, solid dielectric, and hollow dielectric waveguides indicates future radiant-electric EWEC research should aim toward dielectric materials for maximum conversion efficiency. It was also found that the absorber bandwidth is a theoretical limitation on radiant-electric conversion efficiency. Ideally, the absorbers' wavelength would be centered on the irradiating spectrum and have the same bandwith as the irradiating wave. The EWEC concept appears to have a valid scientific basis, but considerable more research is needed before it is thoroughly understood, especially for the complex randomly polarized, wide band, phase incoherent spectrum of the sun. Specific recommended research areas are identified.

  3. Examination of spent fuel radiation energy conversion for electricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Haneol; Yim, Man-Sung, E-mail: msyim@kaist.ac.kr

    2016-04-15

    Highlights: • Utilizing conversion of radiation energy of spent fuel to electric energy. • MCNPX modeling and experiment were used to estimate energy conversion. • The converted energy may be useful for nuclear security applications. • The converted energy may be utilized for safety applications through energy storage. - Abstract: Supply of electricity inside nuclear power plant is one of the most important considerations for nuclear safety and security. In this study, generation of electric energy by converting radiation energy of spent nuclear fuel was investigated. Computational modeling work by using MCNPX 2.7.0 code along with experiment was performed to estimate the amount of electric energy generation. The calculation using the developed modeling work was validated through comparison with an integrated experiment. The amount of electric energy generation based on a conceptual design of an energy conversion module was estimated to be low. But the amount may be useful for nuclear security applications. An alternative way of utilizing the produced electric energy could be considered for nuclear safety application through energy storage. Further studies are needed to improve the efficiency of the proposed energy conversion concept and to examine the issue of radiation damage and economic feasibility.

  4. On the Energy Conversion Efficiency of Piezoelectric Vibration Energy Harvesting Devices

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Eun [Catholic University of Daegu, Kyungsan (Korea, Republic of)

    2015-05-15

    To properly design and assess a piezoelectric vibration energy harvester, it is necessary to consider the application of an efficiency measure of energy conversion. The energy conversion efficiency is defined in this work as the ratio of the electrical output power to the mechanical input power for a piezoelectric vibration energy harvester with an impedance-matched load resistor. While previous research works employed the electrical output power for approximate impedance-matched load resistance, this work derives an efficiency measure considering optimally matched resistance. The modified efficiency measure is validated by comparing it with finite element analysis results for piezoelectric vibration energy harvesters with three different values of the electro-mechanical coupling coefficient. New findings on the characteristics of energy conversion and conversion efficiency are also provided for the two different impedance matching methods.

  5. Wind energy conversion 1994. Proceedings

    International Nuclear Information System (INIS)

    Elliot, G.

    1995-01-01

    At the British Wind Energy Association's 16th Annual Conference, held in Stirling, over 60 high quality papers were presented, including a session devoted to 'Wind Energy in Scotland'. Under the Non Fossil Fuel Obligation (NFFO) wind energy has experienced rapid growth in England and Wales and with Scotland now having its own 'Scottish Renewables Obligation' (SRO) the opportunity to tap one of Europe's most important renewable energy resources now exists. The main contemporary issues concerning wind farming today, namely technical, social, economic and environmental were examined in the Geoff Pontin Memorial Lecture, which focused on these aspects in the context of grid integrated wind energy development. The remaining conference themes included machine development, aerodynamics and control, small machines, fatigue and dynamics, public attitudes, noise emissions, electrical integration, resource measurement, and standards, safety and planning. (author)

  6. Ion-driver fast ignition: Reducing heavy-ion fusion driver energy and cost, simplifying chamber design, target fab, tritium fueling and power conversion

    Energy Technology Data Exchange (ETDEWEB)

    Logan, G.; Callahan-Miller, D.; Perkins, J.; Caporaso, G.; Tabak, M.; Moir, R.; Meier, W.; Bangerter, Roger; Lee, Ed

    1998-04-01

    Ion fast ignition, like laser fast ignition, can potentially reduce driver energy for high target gain by an order of magnitude, while reducing fuel capsule implosion velocity, convergence ratio, and required precisions in target fabrication and illumination symmetry, all of which should further improve and simplify IFE power plants. From fast-ignition target requirements, we determine requirements for ion beam acceleration, pulse-compression, and final focus for advanced accelerators that must be developed for much shorter pulses and higher voltage gradients than today's accelerators, to deliver the petawatt peak powers and small focal spots ({approx}100 {micro}m) required. Although such peak powers and small focal spots are available today with lasers, development of such advanced accelerators is motivated by the greater likely efficiency of deep ion penetration and deposition into pre-compressed 1000x liquid density DT cores. Ion ignitor beam parameters for acceleration, pulse compression, and final focus are estimated for two examples based on a Dielectric Wall Accelerator; (1) a small target with {rho}r {approx} 2 g/cm{sup 2} for a small demo/pilot plant producing {approx}40 MJ of fusion yield per target, and (2) a large target with {rho}r {approx} 10 g/cm{sup 2} producing {approx}1 GJ yield for multi-unit electricity/hydrogen plants, allowing internal T-breeding with low T/D ratios, >75 % of the total fusion yield captured for plasma direct conversion, and simple liquid-protected chambers with gravity clearing. Key enabling development needs for ion fast ignition are found to be (1) ''Close-coupled'' target designs for single-ended illumination of both compressor and ignitor beams; (2) Development of high gradient (>25 MV/m) linacs with high charge-state (q {approx} 26) ion sources for short ({approx}5 ns) accelerator output pulses; (3) Small mm-scale laser-driven plasma lens of {approx}10 MG fields to provide steep focusing angles

  7. Ion-driver fast ignition: Reducing heavy-ion fusion driver energy and cost, simplifying chamber design, target fab, tritium fueling and power conversion

    International Nuclear Information System (INIS)

    Logan, G.; Callahan-Miller, D.; Perkins, J.; Caporaso, G.; Tabak, M.; Moir, R.; Meier, W.; Bangerter, Roger; Lee, Ed

    1998-01-01

    Ion fast ignition, like laser fast ignition, can potentially reduce driver energy for high target gain by an order of magnitude, while reducing fuel capsule implosion velocity, convergence ratio, and required precisions in target fabrication and illumination symmetry, all of which should further improve and simplify IFE power plants. From fast-ignition target requirements, we determine requirements for ion beam acceleration, pulse-compression, and final focus for advanced accelerators that must be developed for much shorter pulses and higher voltage gradients than today's accelerators, to deliver the petawatt peak powers and small focal spots (∼100 (micro)m) required. Although such peak powers and small focal spots are available today with lasers, development of such advanced accelerators is motivated by the greater likely efficiency of deep ion penetration and deposition into pre-compressed 1000x liquid density DT cores. Ion ignitor beam parameters for acceleration, pulse compression, and final focus are estimated for two examples based on a Dielectric Wall Accelerator; (1) a small target with ρr ∼ 2 g/cm 2 for a small demo/pilot plant producing ∼40 MJ of fusion yield per target, and (2) a large target with ρr ∼ 10 g/cm 2 producing ∼1 GJ yield for multi-unit electricity/hydrogen plants, allowing internal T-breeding with low T/D ratios, >75 % of the total fusion yield captured for plasma direct conversion, and simple liquid-protected chambers with gravity clearing. Key enabling development needs for ion fast ignition are found to be (1) ''Close-coupled'' target designs for single-ended illumination of both compressor and ignitor beams; (2) Development of high gradient (>25 MV/m) linacs with high charge-state (q ∼ 26) ion sources for short (∼5 ns) accelerator output pulses; (3) Small mm-scale laser-driven plasma lens of ∼10 MG fields to provide steep focusing angles close-in to the target (built-in as part of each target); (4) beam space charge

  8. The Research and Development of the Radioisotope Energy Conversion System

    International Nuclear Information System (INIS)

    Steinfelds, E.V.; Ghosh, T.K.; Prelas, M.A.; Tompson, R.V.; Loyalka, S.K.

    2001-01-01

    The project of developing radioisotope energy conversion system (RECS) involves analytical computational assisted design and modeling and also laboratory research. The computational analysis consists of selecting various geometries and materials for the main RECS container and the internally located radioisotope, computing the fluxes of the beta (-) particles and of the visible (or ultraviolet) photons produced by the beta (-) s, computing the transport of these photons to the photovoltaic cells, and computing the overall efficiency of useful conversion of the radioisotope power

  9. Conceptual design of a FGM thermoelectric energy conversion system for high temperature heat source. 1. Design of thermoelectric energy conversion unit

    International Nuclear Information System (INIS)

    Kambe, Mitsuru; Teraki, Junichi; Hirano, Toru.

    1996-01-01

    Thermoelectric (TE) power conversion system has been focused as a candidate of direct energy conversion systems for high temperature heat source to meet the various power requirements in next century. A concept of energy conversion unit by using TE cell elements combined with FGM compliant pads has been presented to achieve high thermal energy density as well as high energy conversion efficiency. An energy conversion unit consists of 8 couples of P-N cell elements sandwiched between two FGM compliant pads. Performance analysis revealed that the power generated by this unit was 11 watts which is nearly ten times as much as conventional unit of the same size. Energy conversion efficiency of 12% was expected based on the assumption of ZT = 1. All the member of compliant pads as well as TE cells could be bonded together to avoid thermal resistance. (author)

  10. Synergistic energy conversion process using nuclear energy and fossil fuels

    International Nuclear Information System (INIS)

    Hori, Masao

    2007-01-01

    Because primary energies such as fossil fuels, nuclear energy and renewable energy are limited in quantity of supply, it is necessary to use available energies effectively for the increase of energy demand that is inevitable this century while keeping environment in good condition. For this purpose, an efficient synergistic energy conversion process using nuclear energy and fossil fuels together converted to energy carriers such are electricity, hydrogen, and synthetic fuels seems to be effective. Synergistic energy conversion processes containing nuclear energy were surveyed and effects of these processes on resource saving and the CO 2 emission reduction were discussed. (T.T.)

  11. Feasibility study on conversion and storage of solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Senghaphan, W; Tunsiri, P; Trivijitkasem, P; Ratanathammaphan, K

    1982-01-01

    A study has been conducted on the energy conversion system from solar energy to mechanical energy and on the efficiency of energy storage by an ordinary battery. The conversion system makes use of a thermal cycle, that is to say, the solar energy is collected as heat, and this heat makes suitable working substances evaporate into vapor with volume and pressure which can be used to drive the turbine resulting in mechanical energy. The vapor which passes through the turbine will have reduced pressure and reduced temperature and will be recondensed into liquid after passing through a suitable radiator. This liquid can be pumped back into the hot part of the conversion system with little energy. It is found by this study that the turbine could be operated by using acetone as working substance with a 80-90/sup 0/C source of heat. In the energy conversion system from solar energy to electrical energy, it is essential to provide for an energy storage, so that energy can be used in the absence of sunshine. To store energy by using a batter is one of the convenient methods. Therefore the efficiency of the batteries has been studied. Owing to incompleteness of the researched system, a conventional DC power supply has been used for charging the batteries. It is found that the efficiency of the charging and discharging cycle of batteries is about 40-60%.

  12. Energy production, conversion, storage, conservation, and coupling

    CERN Document Server

    Demirel, Yaşar

    2012-01-01

    Understanding the sustainable use of energy in various processes is an integral part of engineering and scientific studies, which rely on a sound knowledge of energy systems. Whilst many institutions now offer degrees in energy-related programs, a comprehensive textbook, which introduces and explains sustainable energy systems and can be used across engineering and scientific fields, has been lacking. Energy: Production, Conversion, Storage, Conservation, and Coupling provides the reader with a practical understanding of these five main topic areas of energy including 130 examples and over 600 practice problems. Each chapter contains a range of supporting figures, tables, thermodynamic diagrams and charts, while the Appendix supplies the reader with all the necessary data including the steam tables. This new textbook presents a clear introduction of basic vocabulary, properties, forms, sources, and balances of energy before advancing to the main topic areas of: • Energy production and conversion in importa...

  13. Revisit ocean thermal energy conversion system

    International Nuclear Information System (INIS)

    Huang, J.C.; Krock, H.J.; Oney, S.K.

    2003-01-01

    The earth, covered more than 70.8% by the ocean, receives most of its energy from the sun. Solar energy is transmitted through the atmosphere and efficiently collected and stored in the surface layer of the ocean, largely in the tropical zone. Some of the energy is re-emitted to the atmosphere to drive the hydrologic cycle and wind. The wind field returns some of the energy to the ocean in the form of waves and currents. The majority of the absorbed solar energy is stored in vertical thermal gradients near the surface layer of the ocean, most of which is in the tropical region. This thermal energy replenished each day by the sun in the tropical ocean represents a tremendous pollution-free energy resource for human civilization. Ocean Thermal Energy Conversion (OTEC) technology refers to a mechanical system that utilizes the natural temperature gradient that exists in the tropical ocean between the warm surface water and the deep cold water, to generate electricity and produce other economically valuable by-products. The science and engineering behind OTEC have been studied in the US since the mid-seventies, supported early by the U.S. Government and later by State and private industries. There are two general types of OTEC designs: closed-cycle plants utilize the evaporation of a working fluid, such as ammonia or propylene, to drive the turbine-generator, and open-cycle plants use steam from evaporated sea water to run the turbine. Another commonly known design, hybrid plants, is a combination of the two. OTEC requires relatively low operation and maintenance costs and no fossil fuel consumption. OTEC system possesses a formidable potential capacity for renewable energy and offers a significant elimination of greenhouse gases in producing power. In addition to electricity and drinking water, an OTEC system can produce many valuable by-products and side-utilizations, such as: hydrogen, air-conditioning, ice, aquaculture, and agriculture, etc. The potential of these

  14. Electrochemistry of Nanocomposite Materials for Energy Conversion

    OpenAIRE

    Boni, Alessandro

    2016-01-01

    Energy is the most relevant technological issue that the world experiences today, and the development of efficient technologies able to store and convert energy in different forms is urgently needed. The storage of electrical energy is of major importance and electrochemical processes are particularly suited for the demanding task of an efficient inter-conversion. A potential strategy is to store electricity into the chemical bonds of electrogenerated fuels, like hydrogen and/or energy-den...

  15. Oscillating thermionic conversion for high-density space power

    International Nuclear Information System (INIS)

    Jacobson, D.L.; Morris, J.F.

    1988-01-01

    The compactness, maneuverability, and productive weight utilization of space nuclear reactors benefit from the use of thermionic converters at high temperature. Nuclear-thermionic-conversion power requirements are discussed, and the role of oscillations in thermionic energy conversion (TEC) history is examined. Proposed TEC oscillations are addressed, and the results of recent studies of TEC oscillations are reviewed. The possible use of high-frequency TEC oscillations to amplify low-frequency ones is considered. The accomplishments of various programs studying the use of high-temperature thermionic oscillators are examined. 16 references

  16. Ultra-capacitors in power conversion systems analysis, modeling and design in theory and practice

    CERN Document Server

    Grbovic, Petar J

    2014-01-01

    Divided into five parts, this book is focused on ultra-capacitors and their applications in power conversion systems. It discusses ultra-capacitor analysis, modelling and module design from a macroscopic (application) perspective. It also describes power conversion applications, interface dc-dc converter design and entire conversion system design. Part One covers the background of energy storage technologies, with particular attention on state-of-the-art ultra-capacitor energy storage technologies. In Chapter four of this part, power conversion systems with integrated energy storage is discus

  17. Energy technology sources, systems and frontier conversion

    CERN Document Server

    Ohta, Tokio

    1994-01-01

    This book provides a concise and technical overview of energy technology: the sources of energy, energy systems and frontier conversion. As well as serving as a basic reference book for professional scientists and students of energy, it is intended for scientists and policy makers in other disciplines (including practising engineers, biologists, physicists, economists and managers in energy related industries) who need an up-to-date and authoritative guide to the field of energy technology.Energy systems and their elemental technologies are introduced and evaluated from the view point

  18. Polymers for energy storage and conversion

    CERN Document Server

    Mittal, Vikas

    2013-01-01

    One of the first comprehensive books to focus on the role of polymers in the burgeoning energy materials market Polymers are increasingly finding applications in the areas of energy storage and conversion. A number of recent advances in the control of the polymer molecular structure which allows the polymer properties to be more finely tuned have led to these advances and new applications. Polymers for Energy Storage and Conversion assimilates these advances in the form of a comprehensive text that includes the synthesis and properties of a large number of polymer systems for

  19. Rectenna session: Micro aspects. [energy conversion

    Science.gov (United States)

    Gutmann, R. J.

    1980-01-01

    Two micro aspects of the rectenna design are addressed: evaluation of the degradation in net rectenna RF to DC conversion efficiency due to power density variations across the rectenna (power combining analysis) and design of Yagi-Uda receiving elements to reduce rectenna cost by decreasing the number of conversion circuits (directional receiving elements). The first of these micro aspects involves resolving a fundamental question of efficiency potential with a rectenna, while the second involves a design modification with a large potential cost saving.

  20. Ocean thermal energy conversion: Perspective and status

    Science.gov (United States)

    Thomas, Anthony; Hillis, David L.

    The use of the thermal gradient between the warm surface waters and the deep cold waters of tropical oceans was first proposed by J. A. d'Arsonval in 1881 and tried unsuccessfully by George Claude in 1930. Interest in Ocean Thermal Energy Conversion (OTEC) and other renewable energy sources revived in the 1970s as a result of oil embargoes. At that time, the emphasis was on large floating plants miles from shore producing 250 to 400 MW for maintained grids. When the problems of such plants became better understood and the price of oil reversed its upward trend, the emphasis shifted to smaller (10 MW) shore based plants on tropical islands. Such plants would be especially attractive if they produce fresh water as a by-product. During the past 15 years, major progress has been made in converting OTEC unknowns into knowns. Mini-OTEC proved the closed cycle concept. Cost effective heat exchanger concepts were identified. An effective biofouling control technique was discovered. Aluminum was determined to be promising for OTEC heat exchangers. Heat transfer augmentation techniques were identified, which promised a reduction on heat exchanger size and cost. Fresh water was produced by an OTEC open cycle flash evaporator, using the heat energy in the seawater itself. The current R and D emphasis is on the design and construction of a test facility to demonstrate the technical feasibility of the open cycle process. The 10 MW shore-based, closed cycle plant can be built with today's technology; with the incorporation of a flash evaporator, it will produce fresh water as well as electrical power; both valuable commodities on many tropical islands. The open cycle process has unknowns that require solution before the technical feasibility can be demonstrated. The economic viability of either cycle depends on reducing the capital costs of OTEC plants and on future trends in the costs of conventional energy sources.

  1. Proceedings of the 30. intersociety energy conversion engineering conference. Volume 1

    International Nuclear Information System (INIS)

    Goswami, D.Y.; Kannberg, L.D.; Somasundaram, S.

    1995-01-01

    This conference provides a forum to present and discuss the engineering aspects of energy conversion, advanced and unconventional energy systems and devices, energy conversion and utilization, environmental issues and policy implications on research, development, and implementation of technologies. The solution for a sustainable future will lie in a mix of all of the available energy resources (renewable and non-renewable) and diverse energy conversion technologies that will maintain quality of life in a sustainable manner. The 129 papers in Volume 1 deal with aerospace power and are divided into the following topical sections: Aircraft power; Aerospace power systems; Batteries for aerospace power; Computer simulation; Power electronics; Power management; Space solar power; Space power systems; Space energy statics/dynamics; Space power--requirements and issues; Space Station power; Terrestrial applications of space power; Thermal management; Wireless transmission; Space nuclear power; Bimodal propulsion; Electric propulsion; Solar thermal; and Solar bimodal. All papers have been processed separately for inclusion on the data base

  2. Organohalide Perovskites for Solar Energy Conversion.

    Science.gov (United States)

    Lin, Qianqian; Armin, Ardalan; Burn, Paul L; Meredith, Paul

    2016-03-15

    Lead-based organohalide perovskites have recently emerged as arguably the most promising of all next generation thin film solar cell technologies. Power conversion efficiencies have reached 20% in less than 5 years, and their application to other optoelectronic device platforms such as photodetectors and light emitting diodes is being increasingly reported. Organohalide perovskites can be solution processed or evaporated at low temperatures to form simple thin film photojunctions, thus delivering the potential for the holy grail of high efficiency, low embedded energy, and low cost photovoltaics. The initial device-driven "perovskite fever" has more recently given way to efforts to better understand how these materials work in solar cells, and deeper elucidation of their structure-property relationships. In this Account, we focus on this element of organohalide perovskite chemistry and physics in particular examining critical electro-optical, morphological, and architectural phenomena. We first examine basic crystal and chemical structure, and how this impacts important solar-cell related properties such as the optical gap. We then turn to deeper electronic phenomena such as carrier mobilities, trap densities, and recombination dynamics, as well as examining ionic and dielectric properties and how these two types of physics impact each other. The issue of whether organohalide perovskites are predominantly nonexcitonic at room temperature is currently a matter of some debate, and we summarize the evidence for what appears to be the emerging field consensus: an exciton binding energy of order 10 meV. Having discussed the important basic chemistry and physics we turn to more device-related considerations including processing, morphology, architecture, thin film electro-optics and interfacial energetics. These phenomena directly impact solar cell performance parameters such as open circuit voltage, short circuit current density, internal and external quantum efficiency

  3. US energy conversion and use characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Imhoff, C.H.; Liberman, A.; Ashton, W.B.

    1982-02-01

    The long-range goal of the Energy Conversion and Utilization Technology (ECUT) Program is to enhance energy productivity in all energy-use sectors by supporting research on improved efficiency and fuel switching capability in the conversion and utilization of energy. Regardless of the deficiencies of current information, a summary of the best available energy-use information is needed now to support current ECUT program planning. This document is the initial draft of this type of summary and serves as a data book that will present current and periodically updated descriptions of the following aspects of energy use: gross US energy consumption in each major energy-use sector; energy consumption by fuel type in each sector; energy efficiency of major equipment/processes; and inventories, replacement rates, and use patterns for major energy-using capital stocks. These data will help the ECUT program staff perform two vital planning functions: determine areas in which research to improve energy productivity might provide significant energy savings or fuel switching and estimate the actual effect that specific research projects may have on energy productivity and conservation. Descriptions of the data sources and examples of the uses of the different types of data are provided in Section 2. The energy-use information is presented in the last four sections; Section 3 contains general, national consumption data; and Sections 4 through 6 contain residential/commercial, industrial, and transportation consumption data, respectively. (MCW)

  4. Proceedings of the 27th intersociety energy conversion engineering conference

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This book contains the proceedings of the 27th Intersociety Energy Conversion Engineering Conference. Topics included: Stirling Cycle Analysis; Stirling Cycle Models; Stirling Refrigerators/Heat Pumps and Cryocoolers; Domestic Policy; Efficiency/Conservation; Stirling Solar Terrestrial; Stirling Component Technology; Environmental Impacts; Renewable Resource Systems; Stirling Power Generation; Stirling Heat Transport System Technology; and Stirling Cycle Loss Understanding

  5. Proceedings of the 25th Intersociety Energy Conversion Engineering Conference

    International Nuclear Information System (INIS)

    Nelson, P.A.; Schertz, W.W.; Till, R.H.

    1990-01-01

    This book contains papers presented at a conference on energy conversion engineering. Topics covered include: USAF space power requirements, modelling of the dynamics of a low speed gas-liquid heat engine, and comparative assessment of single-axis force generation mechanisms for superconducting suspensions

  6. Energy conversion in natural and artificial photosynthesis.

    Science.gov (United States)

    McConnell, Iain; Li, Gonghu; Brudvig, Gary W

    2010-05-28

    Modern civilization is dependent upon fossil fuels, a nonrenewable energy source originally provided by the storage of solar energy. Fossil-fuel dependence has severe consequences, including energy security issues and greenhouse gas emissions. The consequences of fossil-fuel dependence could be avoided by fuel-producing artificial systems that mimic natural photosynthesis, directly converting solar energy to fuel. This review describes the three key components of solar energy conversion in photosynthesis: light harvesting, charge separation, and catalysis. These processes are compared in natural and in artificial systems. Such a comparison can assist in understanding the general principles of photosynthesis and in developing working devices, including photoelectrochemical cells, for solar energy conversion. 2010 Elsevier Ltd. All rights reserved.

  7. Surface Plasmon-Assisted Solar Energy Conversion.

    Science.gov (United States)

    Dodekatos, Georgios; Schünemann, Stefan; Tüysüz, Harun

    2016-01-01

    The utilization of localized surface plasmon resonance (LSPR) from plasmonic noble metals in combination with semiconductors promises great improvements for visible light-driven photocatalysis, in particular for energy conversion. This review summarizes the basic principles of plasmonic photocatalysis, giving a comprehensive overview about the proposed mechanisms for enhancing the performance of photocatalytically active semiconductors with plasmonic devices and their applications for surface plasmon-assisted solar energy conversion. The main focus is on gold and, to a lesser extent, silver nanoparticles in combination with titania as semiconductor and their usage as active plasmonic photocatalysts. Recent advances in water splitting, hydrogen generation with sacrificial organic compounds, and CO2 reduction to hydrocarbons for solar fuel production are highlighted. Finally, further improvements for plasmonic photocatalysts, regarding performance, stability, and economic feasibility, are discussed for surface plasmon-assisted solar energy conversion.

  8. Energy conversion & storage program. 1995 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, E.J.

    1996-06-01

    The 1995 annual report discusses laboratory activities in the Energy Conversion and Storage (EC&S) Program. The report is divided into three categories: electrochemistry, chemical applications, and material applications. Research performed in each category during 1995 is described. Specific research topics relate to the development of high-performance rechargeable batteries and fuel cells, the development of high-efficiency thermochemical processes for energy conversion, the characterization of new chemical processes and complex chemical species, and the study and application of novel materials related to energy conversion and transmission. Research projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials and deposition technologies, and advanced methods of analysis.

  9. Power electronic converter systems for direct drive renewable energy applications

    DEFF Research Database (Denmark)

    Chen, Zhe

    2013-01-01

    This chapter presents power electronic conversion systems for wind and marine energy generation applications, in particular, direct drive generator energy conversion systems. Various topologies are presented and system design optimization and reliability are briefly discussed....

  10. Energy conversion processes for the use of geothermal heat

    Energy Technology Data Exchange (ETDEWEB)

    Minder, R. [Minder Energy Consulting, Oberlunkhofen (Switzerland); Koedel, J.; Schaedle, K.-H.; Ramsel, K. [Gruneko AG, Basel (Switzerland); Girardin, L.; Marechal, F. [Swiss Federal Institute of Technology (EPFL), Laboratory for industrial energy systems (LENI), Lausanne (Switzerland)

    2007-03-15

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) presents the results of a study made on energy conversion processes that can be used when geothermal heat is to be used. The study deals with both theoretical and practical aspects of the conversion of geothermal heat to electricity. The report is divided into several parts and covers general study, practical experience, planning and operation of geothermal power plants as well as methodology for the optimal integration of energy conversion systems in geothermal power plants. In the first part, the specific properties and characteristics of geothermal resources are discussed. Also, a general survey of conversion processes is presented with special emphasis on thermo-electric conversion. The second part deals with practical aspects related to planning, construction and operation of geothermal power plant. Technical basics, such as relevant site-specific conditions, drilling techniques, thermal water or brine quality and materials requirements. Further, planning procedures are discussed. Also, operation and maintenance aspects are examined and some basic information on costs is presented. The third part of the report presents the methodology and results for the optimal valorisation of the thermodynamic potential of deep geothermal systems.

  11. Silicon nanowires for photovoltaic solar energy conversion.

    Science.gov (United States)

    Peng, Kui-Qing; Lee, Shuit-Tong

    2011-01-11

    Semiconductor nanowires are attracting intense interest as a promising material for solar energy conversion for the new-generation photovoltaic (PV) technology. In particular, silicon nanowires (SiNWs) are under active investigation for PV applications because they offer novel approaches for solar-to-electric energy conversion leading to high-efficiency devices via simple manufacturing. This article reviews the recent developments in the utilization of SiNWs for PV applications, the relationship between SiNW-based PV device structure and performance, and the challenges to obtaining high-performance cost-effective solar cells.

  12. MATERIALS REQUIREMENTS FOR THERMIONIC ENERGY CONVERSION

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R. C.; Skeen, C. H.

    1963-03-15

    The fundamentals of the thermionic energy conversion and its potential applications are reviewed. Materials problems associated with thermionic emitters are considered in relation to the following: work function; emissivity; vaporization; thermal, mechanical, and electrical properties; chemical stability; permeation; and stability under nuclear radiation. Cesium purity and materials suitable for collectors, electrical leads, support structures, insulators, and seals are also discussed. Experimental work on problems involved is reviewed. It is concluded that significant developments have occurred recently in all areas of thermionic energy conversion. (40 references) (A.G.W.)

  13. Turbostar: an ICF reactor using both direct and thermal power conversion. Revision 1

    International Nuclear Information System (INIS)

    Pitts, J.H.

    1986-01-01

    Combining direct and thermal power conversion results in a 52% gross plant efficiency with DT fuel and 68% with advanced DD fuel. We maximize the fraction of fusion-yield energy converted to kinetic energy in a liquid-lithium blanket, and use this energy directly with turbine generators to produce electricity. We use the remainder of the energy to produce electricity in a standard Rankine thermal power conversion cycle

  14. Solid State Energy Conversion Energy Alliance (SECA)

    Energy Technology Data Exchange (ETDEWEB)

    Hennessy, Daniel [Delphi Automotive Systems, LLC, Troy, MI (United States); Sibisan, Rodica [Delphi Automotive Systems, LLC, Troy, MI (United States); Rasmussen, Mike [Delphi Automotive Systems, LLC, Troy, MI (United States)

    2011-09-12

    The overall objective is to develop a solid oxide fuel cell (SOFC) stack that can be economically produced in high volumes and mass customized for different applications in transportation, stationary power generation, and military market sectors. In Phase I, work will be conducted on system design and integration, stack development, and development of reformers for natural gas and gasoline. Specifically, Delphi-Battelle will fabricate and test a 5 kW stationary power generation system consisting of a SOFC stack, a steam reformer for natural gas, and balance-of-plant (BOP) components, having an expected efficiency of 35 percent (AC/LHV). In Phase II and Phase III, the emphasis will be to improve the SOFC stack, reduce start-up time, improve thermal cyclability, demonstrate operation on diesel fuel, and substantially reduce materials and manufacturing cost by integrating several functions into one component and thus reducing the number of components in the system. In Phase II, Delphi-Battelle will fabricate and demonstrate two SOFC systems: an improved stationary power generation system consisting of an improved SOFC stack with integrated reformation of natural gas, and the BOP components, with an expected efficiency of ≥40 percent (AC/LHV), and a mobile 5 kW system for heavy-duty trucks and military power applications consisting of an SOFC stack, reformer utilizing anode tailgate recycle for diesel fuel, and BOP components, with an expected efficiency of ≥30 percent (DC/LHV). Finally, in Phase III, Delphi-Battelle will fabricate and test a 5 kW Auxiliary Power Unit (APU) for mass-market automotive application consisting of an optimized SOFC stack, an optimized catalytic partial oxidation (CPO) reformer for gasoline, and BOP components, having an expected efficiency of 30 percent (DC/LHV) and a factory cost of ≤$400/kW.

  15. Solid State Energy Conversion Energy Alliance (SECA)

    Energy Technology Data Exchange (ETDEWEB)

    Hennessy, Daniel [Delphi Automotive Systems, LLC, Troy, MI (United States); Sibisan, Rodica [Delphi Automotive Systems, LLC, Troy, MI (United States); Rasmussen, Mike [Delphi Automotive Systems, LLC, Troy, MI (United States)

    2011-09-12

    The overall objective is to develop a Solid Oxide Fuel Cell (SOFC) stack that can be economically produced in high volumes and mass customized for different applications in transportation, stationary power generation, and military market sectors. In Phase I, work will be conducted on system design and integration, stack development, and development of reformers for natural gas and gasoline. Specifically, Delphi-Battelle will fabricate and test a 5 kW stationary power generation system consisting of a SOFC stack, a steam reformer for natural gas, and balance-of-plant (BOP) components, having an expected efficiency of ≥ 35 percent (AC/LHV). In Phase II and Phase III, the emphasis will be to improve the SOFC stack, reduce start-up time, improve thermal cyclability, demonstrate operation on diesel fuel, and substantially reduce materials and manufacturing cost by integrating several functions into one component and thus reducing the number of components in the system. In Phase II, Delphi-Battelle will fabricate and demonstrate two SOFC systems: an improved stationary power generation system consisting of an improved SOFC stack with integrated reformation of natural gas, and the BOP components, with an expected efficiency of ≥ 40 percent (AC/LHV), and a mobile 5 kW system for heavy-duty trucks and military power applications consisting of an SOFC stack, reformer utilizing anode tailgate recycle for diesel fuel, and BOP components, with an expected efficiency of ≥ 30 percent (DC/LHV). Finally, in Phase III, Delphi-Battelle will fabricate and test a 5 kW Auxiliary Power Unit (APU) for mass-market automotive application consisting of an optimized SOFC stack, an optimized catalytic partial oxidation (CPO) reformer for gasoline, and BOP components, having an expected efficiency of ≥ 30 percent (DC/LHV) and a factory cost of ≤ $400/kW.

  16. Quantitative analysis of a wind energy conversion model

    International Nuclear Information System (INIS)

    Zucker, Florian; Gräbner, Anna; Strunz, Andreas; Meyn, Jan-Peter

    2015-01-01

    A rotor of 12 cm diameter is attached to a precision electric motor, used as a generator, to make a model wind turbine. Output power of the generator is measured in a wind tunnel with up to 15 m s −1 air velocity. The maximum power is 3.4 W, the power conversion factor from kinetic to electric energy is c p = 0.15. The v 3 power law is confirmed. The model illustrates several technically important features of industrial wind turbines quantitatively. (paper)

  17. Systems and methods for wave energy conversion

    Science.gov (United States)

    MacDonald, Daniel G.; Cantara, Justin; Nathan, Craig; Lopes, Amy M.; Green, Brandon E.

    2017-02-28

    Systems for wave energy conversion that have components that can survive the harsh marine environment and that can be attached to fixed structures, such as a pier, and having the ability to naturally adjust for tidal height and methods for their use are presented.

  18. Review of direct energy conversion for fusion reactors

    International Nuclear Information System (INIS)

    Barr, W.L.; Moir, R.W.

    1976-01-01

    The direct conversion to electrical energy of the energy carried by the leakage plasma from a fusion reactor and by the ions that are not converted to neutrals in a neutral-beam injector is discussed. The conversion process is electrostatic deceleration and direct particle collection as distinct from plasma expansion against a time-varying magnetic field or conversion in an EXB duct (both MHD). Relatively simple 1-stage plasma direct converters are discussed which can have efficiencies of about 50 percent. More complex and costly (measured in $/kW) 2-, 3-, 4-, and 22-stage concepts have been tested at efficiencies approaching 90 percent. Beam direct converters have been tested at 15 keV and 2 kW of power at 70 +- 2 percent efficiency, and a test of a 120-keV, 1-MW version is being prepared. Designs for a 120-keV, 4-MW unit are presented. The beam direct converter, besides saving on power supplies and on beam dumps, should raise the efficiency of creating a neutral beam from 40 percent without direct conversion to 70 percent with direct conversion for a 120-keV deuterium beam. The technological limits determining power handling and lifetime such as space-charge effects, heat removal, electrode material, sputtering, blistering, voltage holding, and insulation design, are discussed. The application of plasma direct converters to toroidal plasma confinement concepts is also discussed

  19. Water-energy nexus: Impact on electrical energy conversion and mitigation by smart water resources management

    International Nuclear Information System (INIS)

    Gjorgiev, Blaže; Sansavini, Giovanni

    2017-01-01

    Highlights: • The issues to energy conversion stemming from the water-energy nexus are investigated. • The objective is to minimize power curtailments caused by critical river water conditions. • A water-energy nexus model for smart management of water resources is developed. • Systemic risks to energy conversion stem from critical temperature and flow regimes. • Full coordination of the hydrologically-linked units provides the most effective strategy. - Abstract: The water-energy nexus refers to the water used to generate electricity and to the electric energy used to collect, clean, move, store, and dispose of water. Water is used in all stages of electric energy conversion making power systems vulnerable to water scarcity and warming. In particular, a water flow decrease and temperature increase in rivers can significantly limit the generation of electricity. This paper investigates the issues to energy conversion stemming from the water-energy nexus and mitigates them by developing a model for the smart utilization of water resources. The objective is to minimize power curtailments caused by a river water flow decrease and a temperature increase. The developed water-energy nexus model integrates the operational characteristics of hydro power plants, the environmental conditions, the river water temperature prediction and thermal load release in river bodies. The application to a hydraulic cascade of hydro and a thermal power plants under drought conditions shows that smart water management entails a significant reduction of power curtailments. In general, the full coordination of the power outputs of the units affected by the hydrological link provides the most effective mitigations of the potential issues stemming from the water-energy nexus. Finally, critical temperature and flow regimes are identified which severely impact the energy conversion and may cause systemic risks in case the generators in one region must be simultaneously curtailed.

  20. Ocean Thermal Energy Conversion power system development. Phase I: preliminary design. Final report. [ODSP-3 code; OTEC Steady-State Analysis Program

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    The following appendices are included; Dynamic Simulation Program (ODSP-3); sample results of dynamic simulation; trip report - NH/sub 3/ safety precautions/accident records; trip report - US Coast Guard Headquarters; OTEC power system development, preliminary design test program report; medium turbine generator inspection point program; net energy analysis; bus bar cost of electricity; OTEC technical specifications; and engineer drawings. (WHK)

  1. Energy Conversion and Storage Program. 1990 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, E.J.

    1992-03-01

    The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes, and (5) application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Topics include identification of new electrochemical couples for advanced rechargeable batteries, improvements in battery and fuel-cell materials, and the establishment of engineering principles applicable to electrochemical energy storage and conversion. Chemical Applications research includes topics such as separations, catalysis, fuels, and chemical analyses. Included in this program area are projects to develop improved, energy-efficient methods for processing waste streams from synfuel plants and coal gasifiers. Other research projects seek to identify and characterize the constituents of liquid fuel-system streams and to devise energy-efficient means for their separation. Materials Applications research includes the evaluation of the properties of advanced materials, as well as the development of novel preparation techniques. For example, the use of advanced techniques, such as sputtering and laser ablation, are being used to produce high-temperature superconducting films.

  2. Integrated solar capacitors for energy conversion and storage

    Institute of Scientific and Technical Information of China (English)

    Ruiyuan Liu; Yuqiang Liu; Haiyang Zou; Tao Song; Baoquan Sun

    2017-01-01

    Solar energy is one of the most popular clean energy sources and is a promising alternative to fulfill the increasing energy demands of modern society.Solar cells have long been under intensive research attention for harvesting energy from sunlight with a high power-conversion efficiency and low cost.However,the power outputs of photovoltaic devices suffer from fluctuations due to the intermittent instinct of the solar radiation.Integrating solar cells and energystorage devices as self-powering systems may solve this problem through the simultaneous storage of the electricity and manipulation of the energy output.This review summarizes the research progress in the integration of new-generation solar cells with supercapacitors,with emphasis on the structures,materials,performance,and new design features.The current challenges and future prospects are discussed with the aim of expanding research and development in this field.

  3. Direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify the design, increase...... efficiency, reduce the product volume and lower its cost. As an example, the principle of operation and the measurements made on a direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp are presented....

  4. Organometallics and related molecules for energy conversion

    CERN Document Server

    Wong, Wai-Yeung

    2015-01-01

    This book presents a critical perspective of the applications of organometallic compounds (including those with metal or metalloid elements) and other related metal complexes as versatile functional materials in the transformation of light into electricity (solar energy conversion) and electricity into light (light generation in light emitting diode), in the reduction of carbon dioxide to useful chemicals, as well as in the safe and efficient production and utilization of hydrogen, which serves as an energy storage medium (i.e. energy carrier). This book focuses on recent research developmen

  5. Innovative direct energy conversion systems from fusion output thermal power to the electrical one with the use of electronic adiabatic processes of electron fluid in solid conductors

    International Nuclear Information System (INIS)

    Kondoh, Y.; Kondo, M.; Shimoda, K.; Takahashi, T.; Osuga, K.

    2003-07-01

    It is shown that with the use of the fusion output and/or environmental thermal energy, innovative open systems for permanent auto-working (PA) direct energy converting (DEC) from the thermal to the electrical (TE) and further to the chemical potential (TEC) energies, abbreviated as PA-TEC-DEC systems, can be used for new auto-working electrical power plants and the plants of the compressible and conveyable hydrogen gas resources at various regions in the whole world. It is analytically shown that the same physical mechanism by free electrons and electrical potential determined by temperature in conductors, which include semiconductors, leads to the Peltier effect and the Seebeck one. It is analytically proved that the energy conservation law is exactly satisfied in a simple form where the net absorbed thermal power is directly transferred to the electrical power and to the chemical power in the PA-TEC-DEC systems. It is analytically and experimentally clarified that the long distance separation between two π type elements of the heat absorption side and the production one of the Peltier effect circuit system or between the higher temperature side and the lower one of the Seebeck effect circuit one does not change mechanisms of the heat pumping by the Peltier effect and of the TE-DEC by the Seebeck effect. The proposed systems gives us freedom of no using the fossil fuel, such as coals, oils, and natural gases that yield serious greenhouse effect all over the earth, and the plant of nuclear fissions that left radiating wastes, i.e., no more environmental pollutions. The PA-TEC-DEC systems can be applicable for several km scale systems to the micro ones, such as the plants of the electrical power and the hydrogen gas resources, compact transportable hydrogen gas producers, the refrigerators, the air conditions, home electrical apparatuses, and further the computer elements. (author)

  6. Geomagnetic activity effects on plasma sheet energy conversion

    Directory of Open Access Journals (Sweden)

    M. Hamrin

    2010-10-01

    Full Text Available In this article we use three years (2001, 2002, and 2004 of Cluster plasma sheet data to investigate what happens to localized energy conversion regions (ECRs in the plasma sheet during times of high magnetospheric activity. By examining variations in the power density, E·J, where E is the electric field and J is the current density obtained by Cluster, we have studied the influence on Concentrated Load Regions (CLRs and Concentrated Generator Regions (CGRs from variations in the geomagnetic disturbance level as expressed by the Kp, the AE, and the Dst indices. We find that the ECR occurrence frequency increases during higher magnetospheric activities, and that the ECRs become stronger. This is true both for CLRs and for CGRs, and the localized energy conversion therefore concerns energy conversion in both directions between the particles and the fields in the plasma sheet. A higher geomagnetic activity hence increases the general level of energy conversion in the plasma sheet. Moreover, we have shown that CLRs live longer during magnetically disturbed times, hence converting more electromagnetic energy. The CGR lifetime, on the other hand, seems to be unaffected by the geomagnetic activity level. The evidence for increased energy conversion during geomagnetically disturbed times is most clear for Kp and for AE, but there are also some indications that energy conversion increases during large negative Dst. This is consistent with the plasma sheet magnetically mapping to the auroral zone, and therefore being more tightly coupled to auroral activities and variations in the AE and Kp indices, than to variations in the ring current region as described by the Dst index.

  7. Energy Conversion at Micro and Nanoscale

    International Nuclear Information System (INIS)

    Gammaitoni, Luca

    2014-01-01

    Energy management is considered a task of strategic importance in contemporary society. It is a common fact that the most successful economies of the planet are the economies that can transform and use large quantities of energy. In this talk we will discuss the role of energy with specific attention to the processes that happens at micro and nanoscale. The description of energy conversion processes at these scales requires approaches that go way beyond the standard equilibrium termodynamics of macroscopic systems. In this talk we will address from a fundamental point of view the physics of the dissipation of energy and will focus our attention to the energy transformation processes that take place in the modern micro and nano information and communication devices

  8. Ultrafast Electron Dynamics in Solar Energy Conversion.

    Science.gov (United States)

    Ponseca, Carlito S; Chábera, Pavel; Uhlig, Jens; Persson, Petter; Sundström, Villy

    2017-08-23

    Electrons are the workhorses of solar energy conversion. Conversion of the energy of light to electricity in photovoltaics, or to energy-rich molecules (solar fuel) through photocatalytic processes, invariably starts with photoinduced generation of energy-rich electrons. The harvesting of these electrons in practical devices rests on a series of electron transfer processes whose dynamics and efficiencies determine the function of materials and devices. To capture the energy of a photogenerated electron-hole pair in a solar cell material, charges of opposite sign have to be separated against electrostatic attractions, prevented from recombining and being transported through the active material to electrodes where they can be extracted. In photocatalytic solar fuel production, these electron processes are coupled to chemical reactions leading to storage of the energy of light in chemical bonds. With the focus on the ultrafast time scale, we here discuss the light-induced electron processes underlying the function of several molecular and hybrid materials currently under development for solar energy applications in dye or quantum dot-sensitized solar cells, polymer-fullerene polymer solar cells, organometal halide perovskite solar cells, and finally some photocatalytic systems.

  9. Inertial confinement fusion reaction chamber and power conversion system study

    International Nuclear Information System (INIS)

    Maya, I.; Schultz, K.R.; Battaglia, J.M.

    1984-09-01

    GA Technologies has developed a conceptual ICF reactor system based on the Cascade rotating-bed reaction chamber concept. Unique features of the system design include the use of low activation SiC in a reaction chamber constructed of box-shaped tiles held together in compression by prestressing tendons to the vacuum chamber. Circulating Li 2 O granules serve as the tritium breeding and energy transport material, cascading down the sides of the reaction chamber to the power conversion system. The total tritium inventory of the system is 6 kg; tritium recovery is accomplished directly from the granules via the vacuum system. A system for centrifugal throw transport of the hot Li 2 O granules from the reaction chamber to the power conversion system has been developed. A number of issues were evaluated during the course of this study. These include the response of first-layer granules to the intense microexplosion surface heat flux, cost effective fabrication of Li 2 O granules, tritium inventory and recovery issues, the thermodynamics of solids-flow options, vacuum versus helium-medium heat transfer, and the tradeoffs of capital cost versus efficiency for alternate heat exchange and power conversion system option. The resultant design options appear to be economically competitive, safe, and environmentally attractive

  10. Modeling and sizing of the heat exchangers of a new supercritical CO2 Brayton power cycle for energy conversion for fusion reactors

    International Nuclear Information System (INIS)

    Serrano, I.P.; Cantizano, A.; Linares, J.I.; Moratilla, B.Y.

    2014-01-01

    Highlights: •We propose a procedure to model the heat exchangers of a S-CO2 Brayton power cycle. •Discretization in sub-heat exchangers is performed due to complex behavior of CO 2 . •Different correlations have been tested, verifying them with CFD when necessary. •Obtained sizes are agree with usual values of printed circuit heat exchangers. -- Abstract: TECNO F US is a research program financed by the Spanish Government to develop technologies related to a dual-coolant (He/Pb–Li) breeding blanket design concept including the auxiliary systems for a future power reactor (DEMO). One of the main issues of this program is the optimization of heat recovery from the reactor and its conversion into electrical power. This paper is focused on the methodology employed for the design and sizing of all the heat exchangers of the supercritical CO 2 Brayton power cycle (S-CO2) proposed by the authors. Due to the large pressure difference between the fluids, and also to their compactness, Printed Circuit Heat Exchangers (PCHE) are suggested in literature for these type of cycles. Because of the complex behavior of CO 2 , their design is performed by a numerical discretization into sub-heat exchangers, thus a higher precision is reached when the thermal properties of the fluids vary along the heat exchanger. Different empirical correlations for the pressure drop and the Nusselt number have been coupled and assessed. The design of the precooler (PC) and the low temperature recuperator (LTR) is also verified by simulations using CFD because of the near-critical behavior of CO 2 . The size of all of the heat exchangers of the cycle have been assessed

  11. Modeling and sizing of the heat exchangers of a new supercritical CO{sub 2} Brayton power cycle for energy conversion for fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, I.P.; Cantizano, A.; Linares, J.I., E-mail: linares@upcomillas.es; Moratilla, B.Y.

    2014-10-15

    Highlights: •We propose a procedure to model the heat exchangers of a S-CO2 Brayton power cycle. •Discretization in sub-heat exchangers is performed due to complex behavior of CO{sub 2}. •Different correlations have been tested, verifying them with CFD when necessary. •Obtained sizes are agree with usual values of printed circuit heat exchangers. -- Abstract: TECNO{sub F}US is a research program financed by the Spanish Government to develop technologies related to a dual-coolant (He/Pb–Li) breeding blanket design concept including the auxiliary systems for a future power reactor (DEMO). One of the main issues of this program is the optimization of heat recovery from the reactor and its conversion into electrical power. This paper is focused on the methodology employed for the design and sizing of all the heat exchangers of the supercritical CO{sub 2} Brayton power cycle (S-CO2) proposed by the authors. Due to the large pressure difference between the fluids, and also to their compactness, Printed Circuit Heat Exchangers (PCHE) are suggested in literature for these type of cycles. Because of the complex behavior of CO{sub 2}, their design is performed by a numerical discretization into sub-heat exchangers, thus a higher precision is reached when the thermal properties of the fluids vary along the heat exchanger. Different empirical correlations for the pressure drop and the Nusselt number have been coupled and assessed. The design of the precooler (PC) and the low temperature recuperator (LTR) is also verified by simulations using CFD because of the near-critical behavior of CO{sub 2}. The size of all of the heat exchangers of the cycle have been assessed.

  12. Air Turbines for Wave Energy Conversion

    Directory of Open Access Journals (Sweden)

    Manabu Takao

    2012-01-01

    Full Text Available This paper describes the present status of the art on air turbines, which could be used for wave energy conversion. The air turbines included in the paper are as follows: Wells type turbines, impulse turbines, radial turbines, cross-flow turbine, and Savonius turbine. The overall performances of the turbines under irregular wave conditions, which typically occur in the sea, have been compared by numerical simulation and sea trial. As a result, under irregular wave conditions it is found that the running and starting characteristics of the impulse type turbines could be superior to those of the Wells turbine. Moreover, as the current challenge on turbine technology, the authors explain a twin-impulse turbine topology for wave energy conversion.

  13. Energy Conversion Loops for Flux-Switching PM Machine Analysis

    Directory of Open Access Journals (Sweden)

    E. Ilhan

    2012-10-01

    Full Text Available Induction and synchronous machines have traditionally been the first choice of automotive manufacturers for electric/hybrid vehicles. However, these conventional machines are not able anymore to meet the increasing demands for a higher energy density due to space limitation in cars. Flux-switching PM (FSPM machines with their high energy density are very suitable to answer this demand. In this paper, the energy conversion loop technique is implemented on FSPM for the first time. The energy conversion technique is a powerful tool for the visualization of machine characteristics, both linear and nonlinear. Further, the technique provides insight into the torque production mechanism. A stepwise explanation is given on how to create these loops for FSPM along with the machine operation.

  14. The Energy Conversation: The First 3 Years

    Science.gov (United States)

    2009-07-01

    emerging clear and present reality] 7“Facing the Hard Truths about Energy” National Petroleum Council, 2007. www.npchardtruthsreport.org 8 Verrastro and...commuting five days/week, dispersing eight tons of pollutants into the environment and using 233 hours for travel to and from work w Telecommuting three... The Energy Conversation the first 3 years Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of

  15. Electro-mechanical energy conversion system having a permanent magnet machine with stator, resonant transfer link and energy converter controls

    Science.gov (United States)

    Skeist, S. Merrill; Baker, Richard H.

    2006-01-10

    An electro-mechanical energy conversion system coupled between an energy source and an energy load comprising an energy converter device including a permanent magnet induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer to control the flow of power or energy through the permanent magnetic induction machine.

  16. Multifunctional Energy Storage and Conversion Devices.

    Science.gov (United States)

    Huang, Yan; Zhu, Minshen; Huang, Yang; Pei, Zengxia; Li, Hongfei; Wang, Zifeng; Xue, Qi; Zhi, Chunyi

    2016-10-01

    Multifunctional energy storage and conversion devices that incorporate novel features and functions in intelligent and interactive modes, represent a radical advance in consumer products, such as wearable electronics, healthcare devices, artificial intelligence, electric vehicles, smart household, and space satellites, etc. Here, smart energy devices are defined to be energy devices that are responsive to changes in configurational integrity, voltage, mechanical deformation, light, and temperature, called self-healability, electrochromism, shape memory, photodetection, and thermal responsivity. Advisable materials, device designs, and performances are crucial for the development of energy electronics endowed with these smart functions. Integrating these smart functions in energy storage and conversion devices gives rise to great challenges from the viewpoint of both understanding the fundamental mechanisms and practical implementation. Current state-of-art examples of these smart multifunctional energy devices, pertinent to materials, fabrication strategies, and performances, are highlighted. In addition, current challenges and potential solutions from materials synthesis to device performances are discussed. Finally, some important directions in this fast developing field are considered to further expand their application. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Systems modeling for a laser-driven IFE power plant using direct conversion

    International Nuclear Information System (INIS)

    Meier, W R

    2008-01-01

    A variety of systems analyses have been conducted for laser driver IFE power plants being developed as part of the High Average Power Laser (HAPL) program. A key factor determining the economics attractiveness of the power plant is the net power conversion efficiency which increases with increasing laser efficiency, target gain and fusion-to-electric power conversion efficiency. A possible approach to increasing the power conversion efficiency is direct conversion of ionized target emissions to electricity. This study examines the potential benefits of increased efficiency when the expanding plasma is inductively coupled to an external circuit allowing some of the ion energy to be directly converted to electricity. For base case direct-drive targets with approximately 24% of the target yield in ions, the benefits are modest, especially for chamber designs that operate at high temperature and thus already have relatively high thermal conversion efficiencies. The reduction in the projected cost of electricity is ∼5-10%

  18. Semiconductor Nanowires and Nanotubes for Energy Conversion

    Science.gov (United States)

    Fardy, Melissa Anne

    In recent years semiconductor nanowires and nanotubes have garnered increased attention for their unique properties. With their nanoscale dimensions comes high surface area and quantum confinement, promising enhancements in a wide range of applications. 1-dimensional nanostructures are especially attractive for energy conversion applications where photons, phonons, and electrons come into play. Since the bohr exciton radius and phonon and electron mean free paths are on the same length scales as nanowire diameters, optical, thermal, and electrical properties can be tuned by simple nanowire size adjustments. In addition, the high surface area inherent to nanowires and nanotubes lends them towards efficient charge separation and superior catalytic performance. In thermoelectric power generation, the nanoscale wire diameter can effectively scatter phonons, promoting reductions in thermal conductivity and enhancements in the thermoelectric figure of merit. To that end, single-crystalline arrays of PbS, PbSe, and PbTe nanowires have been synthesized by a chemical vapor transport approach. The electrical and thermal transport properties of the nanowires were characterized to investigate their potential as thermoelectric materials. Compared to bulk, the lead chalcogenide nanowires exhibit reduced thermal conductivity below 100 K by up to 3 orders of magnitude, suggesting that they may be promising thermoelectric materials. Smaller diameters and increased surface roughness are expected to give additional enhancements. The solution-phase synthesis of PbSe nanowires via oriented attachment of nanoparticles enables facile surface engineering and diameter control. Branched PbSe nanowires synthesized by this approach showed near degenerately doped charge carrier concentrations. Compared to the bulk, the PbSe nanowires exhibited a similar Seebeck coefficient and a significant reduction in thermal conductivity in the temperature range 20 K to 300 K. Thermal annealing of the Pb

  19. Review on the conversion of thermoacoustic power into electricity.

    Science.gov (United States)

    Timmer, Michael A G; de Blok, Kees; van der Meer, Theo H

    2018-02-01

    Thermoacoustic engines convert heat energy into high amplitude acoustic waves and subsequently into electric power. This article provides a review of the four main methods to convert the (thermo)acoustic power into electricity. First, loudspeakers and linear alternators are discussed in a section on electromagnetic devices. This is followed by sections on piezoelectric transducers, magnetohydrodynamic generators, and bidirectional turbines. Each segment provides a literature review of the given technology for the field of thermoacoustics, focusing on possible configurations, operating characteristics, output performance, and analytical and numerical methods to study the devices. This information is used as an input to discuss the performance and feasibility of each method, and to identify challenges that should be overcome for a more successful implementation in thermoacoustic engines. The work is concluded by a comparison of the four technologies, concentrating on the possible areas of application, the conversion efficiency, maximum electrical power output and more generally the suggested focus for future work in the field.

  20. Renewable Energy Operation and Conversion Schemes

    DEFF Research Database (Denmark)

    Spagnuolo, Giovanni; Petrone, Giovanni; Araujo, Samuel Vasconcelos

    2010-01-01

    A short summary of some speeches given during Seminar on Renewable Energy system (SERENE) is presented. The contributions have been mainly focused on power electronics for photovoltaic (PV) and sea wave energies, pointing out some aspects related to efficiency, reliability, and grid integration. ...

  1. Energy conversion options for ARIES-III - A conceptual D-3He tokamak reactor

    International Nuclear Information System (INIS)

    Santarius, J.F.; Blanchard, J.P.; Emmert, G.A.; Sviatoslavsky, I.N.; Wittenberg, L.J.; Ghoneim, N.M.; Hasan, M.Z.; Mau, T.K.; Greenspan, E.; Herring, J.S.; Kernbichler, W.; Klein, A.C.; Miley, G.H.; Miller, R.L.; Peng, Y.K.M.

    1989-01-01

    The potential for highly efficient conversion of fusion power to electricity provides one motivation for investigating D- 3 He fusion reactors. This stems from: (1) the large fraction of D- 3 He power produced in the forms of charged particles and synchrotron radiation which are amenable to direct conversion, and (2) the low neutron fluence and lack of tritium breeding constraints, which increase design flexibility. The design team for a conceptual D- 3 He tokamak reactor, ARIES-III, has investigated numerous energy conversion options at a scoping level in attempting to realize high efficiency. The energy conversion systems have been studied in the context of their use on one or more of three versions of a D- 3 He tokamak: a first stability regime device, a second stability regime device, and a spherical torus. The set of energy conversion options investigated includes bootstrap current conversion, compression-expansion cycles, direct electrodynamic conversion, electrostatic direct conversion, internal electric generator, liquid metal heat engine blanket, liquid metal MHD, plasma MHD, radiation boiler, scrape-off layer thermoelectric, synchrotron radiation conversion by rectennas, synchrotron radiation conversion by thermal cycles, thermionic/AMTEC/thermal systems, and traveling wave conversion. The original set of options is briefly discussed, and those selected for further study are described in more detail. The four selected are liquid metal MHD, plasma MHD, rectenna conversion, and direct electrodynamic conversion. Thermionic energy conversion is being considered, and some options may require a thermal cycle in parallel or series. 17 refs., 3 figs., 1 tab

  2. Nanoscale Materials and Architectures for Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Grulke, Eric A. [Univ. of Kentucky, Lexington, KY (United States); Sunkara, Mahendra K. [University of Louisville, KY (United States)

    2011-05-25

    The Kentucky EPSCoR Program supported an inter-university, multidisciplinary energy-related research cluster studying nanomaterials for converting solar radiation and residual thermal energy to electrical energy and hydrogen. It created a collaborative center of excellence based on research expertise in nanomaterials, architectures, and their synthesis. The project strengthened and improved the collaboration between the University of Louisville, the University of Kentucky, and NREL. The cluster hired a new faculty member for ultra-fast transient spectroscopy, and enabled the mentoring of one research scientist, two postdoctoral scholars and ten graduate students. Work was accomplished with three focused cluster projects: organic and photoelectrochemical solar cells, solar fuels, and thermionic energy conversion.

  3. HVDC transmission power conversion applications in power systems

    CERN Document Server

    Kim, Chan-Ki; Jang, Gil-Soo; Lim, Seong-Joo; Lee, Seok-Jin

    2009-01-01

    HVDC is a critical solution to several major problems encountered when trying to maintain systemic links and quality in large-scale renewable energy environments. HDVC can resolve a number of issues, including voltage stability of AC power networks, reducing fault current, and optimal management of electric power, ensuring the technology will play an increasingly important role in the electric power industry. To address the pressing need for an up-to-date and comprehensive treatment of the subject, Kim, Sood, Jang, Lim and Lee have collaborated to produce this key text and reference.  Combin

  4. Method and device for current driven electric energy conversion

    DEFF Research Database (Denmark)

    2012-01-01

    Device comprising an electric power converter circuit for converting electric energy. The converter circuit comprises a switch arrangement with two or more controllable electric switches connected in a switching configuration and controlled so as to provide a current drive of electric energy from...... configurations such as half bridge buck, full bridge buck, half bridge boost, or full bridge boost. A current driven conversion is advantageous for high efficient energy conversion from current sources such as solar cells or where a voltage source is connected through long cables, e.g. powerline cables for long...... an associated electric source connected to a set of input terminals. This is obtained by the two or more electric swiches being connected and controlled to short-circuit the input terminals during a part of a switching period. Further, a low pass filter with a capacitor and an inductor are provided to low pass...

  5. Model predictive control of wind energy conversion systems

    CERN Document Server

    Yaramasu, Venkata Narasimha R

    2017-01-01

    The authors provide a comprehensive analysis on the model predictive control of power converters employed in a wide variety of variable-speed wind energy conversion systems (WECS). The contents of this book includes an overview of wind energy system configurations, power converters for variable-speed WECS, digital control techniques, MPC, modeling of power converters and wind generators for MPC design. Other topics include the mapping of continuous-time models to discrete-time models by various exact, approximate, and quasi-exact discretization methods, modeling and control of wind turbine grid-side two-level and multilevel voltage source converters. The authors also focus on the MPC of several power converter configurations for full variable-speed permanent magnet synchronous generator based WECS, squirrel-cage induction generator based WECS, and semi-variable-speed doubly fed induction generator based WECS.

  6. Advanced power conversion based on the Aerocapacitor{trademark}. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Roark, D.

    1997-03-05

    This report summarizes work performed under contract No. DE-FC07-94ID13283, {open_quotes}Advanced Power Conversion Based on the Aerocapacitors{trademark}.{close_quotes} Under this contract high power density, high energy density, organic electrolyte Aerocapacitors{trademark} were developed and characterized for power conversion applications. Pilot facilities for manufacturing prototype AA-size Aerocapacitors{trademark} were put in place. The low ESR and good frequency response of these devices show that they are ideal components for high discharge rate and low to moderate frequency (< 10 kHz) applications such as power conversion.

  7. Innovative direct energy conversion systems using electronic adiabatic processes of electron fluid in solid conductors: new plants of electrical power and hydrogen gas resources without environmental pollutions

    International Nuclear Information System (INIS)

    Kondoh, Y.; Kondo, M.; Shimoda, K.; Takahashi, T.

    2001-07-01

    It is shown that using a novel recycling process of the environmental thermal energy, innovative permanent auto-working direct energy converter systems (PA-DEC systems) from the environmental thermal to electrical and/or chemical potential (TE/CP) energies, abbreviated as PA-TE/CP-DEC systems, can be used for new auto-working electrical power plants and the plants of the compressible and conveyable hydrogen gas resources at various regions in the whole world, with contributions to the world peace and the economical development in the south part of the world. It is shown that the same physical mechanism by free electrons and electrical potential determined by temperature in conductors, which include semiconductors, leads to the Peltier effect and the Seebeck one. It is experimentally clarified that the long distance separation between two π type elements of the heat absorption (HAS) and the production one (HPS) of the Peltier effect circuit system or between the higher temperature side (HTS) and the lower one (LTS) of the Seebeck effect circuit one does not change in the whole for the both effects. By using present systems, we do not need to use petrified fuels such as coals, oils, and natural gases in order to decrease the greenhouse effect by the CO 2 surrounding the earth. Furthermore, we do not need plats of nuclear fissions that left radiating wastes, i.e., with no environmental pollutions. The PA-TE/CP-DEC systems can be applicable for several km scale systems to the micro ones, such as the plants of the electrical power, the compact transportable hydrogen gas resources, a large heat energy container, which can be settled at far place from thermal energy absorbing area, the refrigerators, the air conditioners, home electrical apparatuses, and further the computer elements. It is shown that the simplest PA-TE/CP-DEC system can be established by using only the Seebeck effect components and the resolving water ones. It is clarified that the externally applied

  8. Electrical Power Conversion of a River and Tidal Power Generator: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard; Gevorgian, Vahan; Wright, Alan; Donegan, James; Marnagh, Cian; McEntee, Jarlath

    2016-09-01

    As renewable generation has become less expensive during recent decades, and it becomes more accepted by the global population, the focus on renewable generation has expanded to include new types with promising future applications, such as river and tidal generation. Although the utilization of power electronics and electric machines in industry is phenomenal, the emphasis on system design is different for various sectors of industry. In precision control, robotics, and weaponry, the design emphasis is on accuracy and reliability with less concern for the cost of the final product. In energy generation, the cost of energy is the prime concern; thus, capital expenditures (CAPEX) and operations and maintenance expenditures (OPEX) are the major design objectives. This paper describes the electrical power conversion aspects of river and tidal generation. Although modern power converter control is available to control the generation side, the design was chosen on the bases of minimizing the CAPEX and OPEX; thus, the architecture is simple and modular for ease of replacement and maintenance. The power conversion is simplified by considering a simple diode bridge and a DC-DC power converter to take advantage of abundant and low-cost photovoltaic inverters that have well-proven grid integration characteristics (i.e., the capability to produce energy with good power quality and control real power and voltage on the grid side).

  9. Metal oxide-carbon composites for energy conversion and storage

    Science.gov (United States)

    Perera, Sanjaya Dulip

    The exponential growth of the population and the associated energy demand requires the development of new materials for sustainable energy conversion and storage. Expanding the use of renewable energy sources to generate electricity is still not sufficient enough to fulfill the current energy demand. Electricity generation by wind and solar is the most promising alternative energy resources for coal and oil. The first part of the dissertation addresses an alternative method for preparing TiO2 nanotube based photoanodes for DSSCs. This would involve smaller diameter TiO2 nanotubes (˜10 nm), instead of nanoparticles or electrochemically grown larger nanotubes. Moreover, TiO2 nanotube-graphene based photocatalysts were developed to treat model pollutants. In the second part of this dissertation, the development of electrical energy storage systems, which provide high storage capacity and power output using low cost materials are discussed. Among different types of energy storage systems, batteries are the most convenient method to store electrical energy. However, the low power performance of batteries limits the application in different types of electrical energy storage. The development of electrical energy storage systems, which provide high storage capacity and power output using low cost materials are discussed.

  10. Graphene for thermoelectronic solar energy conversion

    Science.gov (United States)

    De, Dilip K.; Olukunle, Olawole C.

    2017-08-01

    Graphene is a high temperature material which can stand temperature as high as 4600 K in vacuum. Even though its work function is high (4.6 eV) the thermionic emission current density at such temperature is very high. Graphene is a wonderful material whose work function can be engineered as desired. Kwon et al41 reported a chemical approach to reduce work function of graphene using K2CO3, Li2CO3, Rb2CO3, Cs2CO3. The work functions are reported to be 3.7 eV, 3.8 eV, 3.5 eV and 3.4 eV. Even though they did not report the high temperature tolerance of such alkali metal carbonate doped graphene, their works open a great promise for use of pure graphene and doped graphene as emitter (cathode) and collector (anode) in a solar thermionic energy converter. This paper discusses the dynamics of solar energy conversion to electrical energy using thermionic energy converter with graphene as emitter and collector. We have considered parabolic mirror concentrator to focus solar energy onto the emitter to achieve temperature around 4300 K. Our theoretical calculations and the modelling show that efficiency as high as 55% can easily be achieved if space-charge problem can be reduced and the collector can be cooled to certain proper temperature. We have discussed methods of controlling the associated space-charge problems. Richardson-Dushman equation modified by the authors have been used in this modelling. Such solar energy conversion would reduce the dependence on silicon solar panel and has great potential for future applications.

  11. Onboard energy conversion and thermal analysis of the MTL system

    International Nuclear Information System (INIS)

    Kadiramangalam, M.N.; Hoffert, M.I.; Miller, G.

    1989-01-01

    A non-nuclear energy conversion concept-MTL (microwave power to low earth orbits) was previously presented in order to supply SDI platforms power in the housekeeping, alert and burst power modes. In this paper the major issues addressed are: system design, integration and analysis. Parametric design of the major subsystems of the MTL bus, which includes the rectenna, the monolithic solid oxide fuel cell etc., is presented. The results of the parametric design, and of computer simulation are used as inputs to construct a comprehensive systems design code. A reference MTL system design which meets the requirements of duty cycles spelled out in open literature is presented. A comparison of mass and power is made between the MTL system and the SP-100 and burst power systems, which demonstrates the competitiveness of the proposed MTL design

  12. Power Technologies Energy Data Book - Fourth Edition

    Energy Technology Data Exchange (ETDEWEB)

    Aabakken, J.

    2006-08-01

    This report, prepared by NREL's Strategic Energy Analysis Center, includes up-to-date information on power technologies, including complete technology profiles. The data book also contains charts on electricity restructuring, power technology forecasts, electricity supply, electricity capability, electricity generation, electricity demand, prices, economic indicators, environmental indicators, and conversion factors.

  13. Power Technologies Energy Data Book - Third Edition

    Energy Technology Data Exchange (ETDEWEB)

    Aabakken, J.

    2005-04-01

    This report, prepared by NREL's Energy Analysis Office, includes up-to-date information on power technologies, including complete technology profiles. The data book also contains charts on electricity restructuring, power technology forecasts, electricity supply, electricity capability, electricity generation, electricity demand, prices, economic indicators, environmental indicators, and conversion factors.

  14. Energy harvesting solar, wind, and ocean energy conversion systems

    CERN Document Server

    Khaligh, Alireza

    2009-01-01

    Also called energy scavenging, energy harvesting captures, stores, and uses ""clean"" energy sources by employing interfaces, storage devices, and other units. Unlike conventional electric power generation systems, renewable energy harvesting does not use fossil fuels and the generation units can be decentralized, thereby significantly reducing transmission and distribution losses. But advanced technical methods must be developed to increase the efficiency of devices in harvesting energy from environmentally friendly, ""green"" resources and converting them into electrical energy.Recognizing t

  15. The photochemical conversion of solar energy into electrical energy: Eosin-Arabinose system

    Energy Technology Data Exchange (ETDEWEB)

    Gangotri, K.M. [Department of Chemistry, Solar Energy Laboratory, Jai Narain Vyas University, Jodhpur 342 033, Rajasthan (India); Bhimwal, Mukesh Kumar [Solar Energy Laboratory, Jai Narain Vyas University, Jodhpur 342 033, Rajasthan (India)

    2010-12-15

    A photosensitizer -Eosin and a reductant- Arabinose have been used in the photogalvanic cell for photochemical conversion of solar energy into electrical energy. The generated photopotential and photocurrent are 679.0 mV and 240.0 {mu}A respectively. The maximum power of the cell is 162.96 {mu}W whereas the observed power at power point is 73.08 {mu}W. The conversion efficiency is 0.7026% and the fill factor is 0.2856 at the power point of the photogalvanic cell. The photogalvanic cell so developed can work for 85.0 min in dark if it is irradiated for 140.0 min i.e. the storage capacity of photogalvanic cell is 60.71%. The effects of different parameters on the electrical output of the photogalvanic cell have been observed. A mechanism has also been proposed for the photogeneration of electrical energy. (author)

  16. Assessment of tidal and wave energy conversion technologies in Canada

    International Nuclear Information System (INIS)

    2009-01-01

    This paper presented an attractive option to help meet Canada's future energy needs, notably the vast and energetic Atlantic, Pacific and Arctic coastal waters which make ocean renewable energy, particularly tidal in-stream energy conversion (TISEC) and wave energy conversion (WEC). There is much uncertainty regarding the possible environmental impacts associated with their deployment and operation. In support of commercial development of the industry, a review of scientific knowledge was needed for the development of policy and regulations consistent with Canada's conservation and sustainability priorities. In April 2009, Fisheries and Oceans Canada (DFO) hosted a two-day national science advisory process meeting in order to determine the current state of knowledge on the environmental impacts of tidal and wave energy conversion technologies and their application in the Canadian context based on published reports. Potential mitigation measures were identified and the feasibility of developing a relevant Canadian statement of practice was determined. This report presented an assessment and analysis of wave power, including the impacts on physical processes; impacts on habitat characteristics; impacts on water quality; impacts of noise and vibrations; impacts of electromagnetic fields; impacts of physical encounters; cumulative impacts; and mitigation measures. It was concluded that there is a recognized need to develop and maintain national and regional georeferenced, interoperable, standards-based databases that enable access by governments, developers, academics, non-governmental organizations and the general public. 1 ref., 1 fig.

  17. Supramolecular Structures for Photochemical Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Gust, Devens; Moore, Thomas A.; Moore, Ana L.

    2003-08-26

    OAK B188 The goal of this project is to mimic the energy transduction processes by which photosynthetic organisms harvest sunlight and convert it to forms of energy that are more easily used and stored. The results may lead to new technologies for solar energy harvesting based on the natural photosynthetic process. They may also enrich our understanding and control of photosynthesis in living organisms, and lead to methods for increasing natural biomass production, carbon dioxide removal, and oxygen generation. In our work to date, we have learned how to make synthetic antenna and reaction center molecules that absorb light and undergo photoinduced electron transfer to generate long-lived, energetic charge-separated states. We have assembled a prototype system in which artificial reaction centers are inserted into liposomes (artificial cell-like constructs), where they carry out light-driven transmembrane translocation of hydrogen ions to generate proton motive force. By insertion of natural ATP synthase into the liposomal bilayer, this proton motive force has been used to power the synthesis of ATP. ATP is a natural biological energy currency. We are carrying out a systematic investigation of these artificial photosynthetic energy harvesting constructs in order to understand better how they operate. In addition, we are exploring strategies for reversing the direction of the light-powered proton pumping. Most recently, we have extended these studies to develop a light-powered transmembrane calcium ion pump that converts sunlight into energy stored as a calcium ion concentration gradient across a lipid bilayer.

  18. Electrohydrodynamics: a high-voltage direct energy conversion process

    International Nuclear Information System (INIS)

    Brun, S.

    1967-04-01

    This analysis consists of a theoretical and practical study of a high-tension electrical power generator based on the Van de Graaff generator principle, the main difference being that the charges produced are transported by a gas in motion and not by a belt. The electrical and thermal properties of such a generator are studied, as well as the difficult problem of the production of the ionised particles used in the conversion. A certain number of results already published on this process for converting kinetic energy into electrical energy is given, as well as some possible applications in the field of space technology. (author) [fr

  19. Analytical investigation of low temperature lift energy conversion systems with renewable energy source

    International Nuclear Information System (INIS)

    Lee, Hoseong; Hwang, Yunho; Radermacher, Reinhard

    2014-01-01

    The efficiency of the renewable energy powered energy conversion system is typically low due to its moderate heat source temperature. Therefore, improving its energy efficiency is essential. In this study, the performance of the energy conversion system with renewable energy source was theoretically investigated in order to explore its design aspect. For this purpose, a computer model of n-stage low temperature lift energy conversion (LTLEC) system was developed. The results showed that under given operating conditions such as temperatures and mass flow rates of heat source and heat sink fluids the unit power generation of the system increased with the number of stage, and it became saturated when the number of staging reached four. Investigation of several possible working fluids for the optimum stage LTLEC system revealed that ethanol could be an alternative to ammonia. The heat exchanger effectiveness is a critical factor on the system performance. The power generation was increased by 7.83% for the evaporator and 9.94% for the condenser with 10% increase of heat exchanger effectiveness. When these low temperature source fluids are applied to the LTLEC system, the heat exchanger performance would be very critical and it has to be designed accordingly. - Highlights: •Energy conversion system with renewable energy is analytically investigated. •A model of multi-stage low temperature lift energy conversion systems was developed. •The system performance increases as the stage number is increased. •The unit power generation is increased with increase of HX effectiveness. •Ethanol is found to be a good alternative to ammonia

  20. Near-field enhanced thermionic energy conversion for renewable energy recycling

    Science.gov (United States)

    Ghashami, Mohammad; Cho, Sung Kwon; Park, Keunhan

    2017-09-01

    This article proposes a new energy harvesting concept that greatly enhances thermionic power generation with high efficiency by exploiting the near-field enhancement of thermal radiation. The proposed near-field enhanced thermionic energy conversion (NETEC) system is uniquely configured with a low-bandgap semiconductor cathode separated from a thermal emitter with a subwavelength gap distance, such that a significant amount of electrons can be photoexcited by near-field thermal radiation to contribute to the enhancement of thermionic current density. We theoretically demonstrate that the NETEC system can generate electric power at a significantly lower temperature than the standard thermionic generator, and the energy conversion efficiency can exceed 40%. The obtained results reveal that near-field photoexcitation can enhance the thermionic power output by more than 10 times, making this hybrid system attractive for renewable energy recycling.

  1. Direct energy conversion of radiation energy in fusion reactor

    International Nuclear Information System (INIS)

    Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

    1993-11-01

    Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generates electricity by temperature gradient in conductors. A strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy conversion are mentioned. (author)

  2. Direct energy conversion of radiation energy in fusion reactor

    Science.gov (United States)

    Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

    1993-11-01

    Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generates electricity by temperature gradient in conductors. A strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy conversion are mentioned.

  3. Direct energy conversion of radiation energy in fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

    1993-11-01

    Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generates electricity by temperature gradient in conductors. A strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy conversion are mentioned. (author).

  4. A Conversation on Zero Net Energy Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Torcellini, Paul A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Eley, Charles [Consultant; Gupta, Smita [Itron; McHugh, Jon [McHugh Energy Consultants; Lui, Bing [Pacific Northwest National Laboratory; Higgins, Cathy [New Buildings Institute; Iplikci, Jessica [Energy Trust of Oregon; Rosenberg, Michael [Pacific Northwest National Laboratory

    2017-06-01

    Recently, zero net energy (ZNE) buildings have moved from state-of-the-art small project demonstrations to a more widely adopted approach across the country among various building types and sizes. States such as California set policy goals of all new residential construction to be NZE by 2020 and all commercial buildings to be NZE by 2030. However, the market for designing, constructing, and operating ZNE buildings is still relatively small. We bring together distinguished experts to share their thoughts on making ZNE buildings more widespread and mainstream from a broad perspective, including governments, utilities, energy-efficiency research institutes, and building owners. This conversation also presents the benefits of ZNE and ways to achieve that goal in the design and operation of buildings. The following is a roundtable conducted by ASHRAE Journal and Bing Liu with Charles Eley, Smita Gupta, Cathy Higgins, Jessica Iplikci, Jon McHugh, Michael Rosenberg, and Paul Torcellini.

  5. Physics for all, who want to join in conversation. On atomic power, dirty bombs, space research, solar energy, and the global heating

    International Nuclear Information System (INIS)

    Muller, Richard A.

    2009-01-01

    Which dangers contains the global heating really? What can happen at an attack on a atomic power plant?. Which chances offer renewable energies? Questions which are put daily in the pursuing of news - but to which we have only seldomly answers ready, because basic physical knowledge is absent. But it must not even be the great world policy. Already at the decision wether solar cells shall be mounted on the roof or punted on geothermal heat physics are not unimportant. More often than we think it are natural sciences, which yield the foundations for important decisions. Richard A. Muller explains simply and illustratively, how physics determines our life. Thereby he removes prejudices and mediates quite surprising insights

  6. Direct energy conversion for fusion reactors

    International Nuclear Information System (INIS)

    Barr, W.L.

    1977-01-01

    Complex multistage plasma converters were tested at efficiencies approaching 90% at low energies and powers, and simpler, more cost-effective versions at 65% efficiency. Laboratory tests of neutral-beam direct converters at 15 keV and 2 kW gave 70% efficiency. A 120-keV, 1.5-MW version is being tested

  7. Magnetic-field-free thermoelectronic power conversion based on graphene and related two-dimensional materials

    Science.gov (United States)

    Wanke, R.; Hassink, G. W. J.; Stephanos, C.; Rastegar, I.; Braun, W.; Mannhart, J.

    2016-06-01

    Mobile energy converters require, in addition to high conversion efficiency and low cost, a low mass. We propose to utilize thermoelectronic converters that use 2D-materials such as graphene for their gate electrodes. Deriving the ultimate limit for their specific energy output, we show that the positive energy output is likely close to the fundamental limit for any conversion of heat into electric power. These converters may be valuable as electric power sources of spacecraft, and with the addition of vacuum enclosures, for power generation in electric planes and cars.

  8. Energy and power alternatives

    International Nuclear Information System (INIS)

    Messerle, H.K.

    1992-01-01

    Taking into consideration the need for a safe energy supply, rising demand for energy worldwide and limited oil reserves, alternative energy resources for bulk power are discussed. They are nuclear fuel, fluidized bed combustion of coal, coal gasification with combined cycle process, coal-oil mixture combustion and MHD power generation process. It is pointed out that the major environmental impact of fossil fuels is in accumulation of greenhouse gases in the atmosphere and air pollution due to sulphur emission. (M.G.B.)

  9. Mechanically stable ternary heterogeneous electrodes for energy storage and conversion.

    Science.gov (United States)

    Gao, Libo; Zhang, Hongti; Surjadi, James Utama; Li, Peifeng; Han, Ying; Sun, Dong; Lu, Yang

    2018-02-01

    Recently, solid asymmetric supercapacitor (ASC) has been deemed as an emerging portable power storage or backup device for harvesting natural resources. Here we rationally engineered a hierarchical, mechanically stable heterostructured FeCo@NiCo layered double hydroxide (LDH) with superior capacitive performance by a simple two-step electrodeposition route for energy storage and conversion. In situ scanning electron microscope (SEM) nanoindentation and electrochemical tests demonstrated the mechanical robustness and good conductivity of FeCo-LDH. This serves as a reliable backbone for supporting the NiCo-LDH nanosheets. When employed as the positive electrode in the solid ASC, the assembly presents high energy density of 36.6 W h kg -1 at a corresponding power density of 783 W kg -1 and durable cycling stability (87.3% after 5000 cycles) as well as robust mechanical stability without obvious capacitance fading when subjected to bending deformation. To demonstrate its promising capability for practical energy storage applications, the ASC has been employed as a portable energy source to power a commercially available digital watch, mini motor car, or household lamp bulb as well as an energy storage reservoir, coupled with a wind energy harvester to power patterned light-emitting diodes (LEDs).

  10. HYLIFE-II power conversion system design and cost study

    International Nuclear Information System (INIS)

    Hoffman, M.A.

    1990-09-01

    The power conversion system for the HYLIFE-2 fusion power plant has been defined to include the IHX's (intermediate heat exchangers) and everything that support the exchange of energy from the reactor. It is referred to simply as the BOP (balance of plant) in the rest of this report. The above is a convenient division between the reactor equipment and the rest of the fusion power plant since the BOP design and cost then depend only on the specification of the thermal power to the IHX's and the temperature of the primary Flibe coolant into and out of the IHX's, and is almost independent of the details of the reactor design. The main efforts during the first year have been on the definition and thermal-hydraulics of the IHX's, the steam generators and the steam power plant, leading to the definition of a reference BOP with the molten salt, Flibe, as the primary coolant. A summary of the key results in each of these areas is given in this report

  11. A Review of Previous Research in Direct Energy Conversion Fission Reactors

    International Nuclear Information System (INIS)

    DUONG, HENRY; POLANSKY, GARY F.; SANDERS, THOMAS L.; SIEGEL, MALCOLM D.

    1999-01-01

    From the earliest days of power reactor development, direct energy conversion was an obvious choice to produce high efficiency electric power generation. Directly capturing the energy of the fission fragments produced during nuclear fission avoids the intermediate conversion to thermal energy and the efficiency limitations of classical thermodynamics. Efficiencies of more than 80% are possible, independent of operational temperature. Direct energy conversion fission reactors would possess a number of unique characteristics that would make them very attractive for commercial power generation. These reactors would be modular in design with integral power conversion and operate at low pressures and temperatures. They would operate at high efficiency and produce power well suited for long distance transmission. They would feature large safety margins and passively safe design. Ideally suited to production by advanced manufacturing techniques, direct energy conversion fission reactors could be produced more economically than conventional reactor designs. The history of direct energy conversion can be considered as dating back to 1913 when Moseleyl demonstrated that charged particle emission could be used to buildup a voltage. Soon after the successful operation of a nuclear reactor, E.P. Wigner suggested the use of fission fragments for direct energy conversion. Over a decade after Wigner's suggestion, the first theoretical treatment of the conversion of fission fragment kinetic energy into electrical potential appeared in the literature. Over the ten years that followed, a number of researchers investigated various aspects of fission fragment direct energy conversion. Experiments were performed that validated the basic physics of the concept, but a variety of technical challenges limited the efficiencies that were achieved. Most research in direct energy conversion ceased in the US by the late 1960s. Sporadic interest in the concept appears in the literature until this

  12. The Energy Conversion Analysis of HTR Gas Turbine System

    International Nuclear Information System (INIS)

    Utaja

    2000-01-01

    The energy conversion analysis of HTR gas turbine system by hand calculation is tedious work and need much time. This difficulty comes from the repeated thermodynamic process calculation, both on compression or expansion of the cycle. To make the analysis faster and wider variable analyzed, HTR-1 programme is used. In this paper, the energy conversion analysis of HTR gas turbine system by HTR-1 will be described. The result is displayed as efficiency curve and block diagram with the input and output temperature of the component. This HTR-1 programme is developed by Basic language programming and be compiled by Visual Basic 5.0 . By this HTR-1 programme, the efficiency, specific power and effective compression of the amount of gas can be recognized fast. For example, for CO 2 gas between 40 o C and 700 o C, the compression on maximum efficiency is 4.6 and the energy specific is 18.9 kcal/kg, while the temperature changing on input and output of the component can be traced on monitor. This process take less than one second, while the manual calculation take more than one hour. It can be concluded, that the energy conversion analysis of the HTR gas turbine system by HTR-1 can be done faster and more variable analyzed. (author)

  13. Net energy from nuclear power

    International Nuclear Information System (INIS)

    Perry, A.M.; Rotty, R.M.; Reister, D.B.

    1977-01-01

    Non-fission energy inputs to nuclear fuel cycles were calculated for four types of power reactors and for two grades of uranium ore. Inputs included all requirements for process operations, materials, and facility construction. Process stages are mining, milling, uranium conversion, enrichment, fuel fabrication, reprocessing, waste disposal, reactor construction and operation, and all transportation. Principal inputs were analyzed explicitly; small contributions and facility construction were obtained from input-output tables. For major facilities, the latter approach was based on disaggregated descriptions. Enrichment energy was that of U.S. diffusion plants, with uranium tails assay retained as a variable parameter. Supplemental electrical requirements, as a percentage of lifetime electrical output, are 5-6% for LWRs (0.3 - 0.2% tails assay) using ores with 0.2% uranium and without recycle. Recycle of uranium and plutonium reduces the electrical requirements 30%. Chattanooga Shales (0.006% U) require one-third more electricity. Thermal energy requirements are about 5% of electrical output with conventional ores; shales raise this to about 14%, with 0.2% enrichment tails and full recycle. About one-tenth of the electrical supplements and about a third of the thermal energy supplements are required prior to operation. A typical LWR will repay its energy loan within 15 months, allowing for low initial load factors. Enrichment requiring only 10% as much separative work as gaseous diffusion would reduce electrical requirements about 80%, but have little effect on thermal energy inputs. HTGRs require slightly less supplemental energy than LWRs. HWRs (with natural uranium) require about one-third as much supplemental electricity, but half again as much thermal energy, largely for heavy water production. The paper presents detailed data for several combinations of reactor type, ore grade and tails assay and compares them with conventional power plants. It also exhibits

  14. Simulation of diesel engine energy conversion processes

    Directory of Open Access Journals (Sweden)

    А. С. Афанасьев

    2016-12-01

    Full Text Available In order to keep diesel engines in good working order the troubleshooting methods shall be improved. For their further improvement by parameters of associated processes a need has arisen to develop a diesel engine troubleshooting method based on time parameters of operating cycle. For such method to be developed a computational experiment involving simulation of diesel engine energy conversion processes has been carried out. The simulation was based on the basic mathematical model of reciprocating internal combustion engines, representing a closed system of equations and relationships. The said model has been supplemented with the engine torque dynamics taking into account the current values of in-cylinder processes with different amounts of fuel injected, including zero feed.The torque values obtained by the in-cylinder pressure conversion does not account for mechanical losses, which is why the base simulation program has been supplemented with calculations for the friction and pumping forces. In order to determine the indicator diagram of idle cylinder a transition to zero fuel feed mode and exclusion of the combustion process from calculation have been provisioned.

  15. Adaptability of solar energy conversion systems on ships

    Science.gov (United States)

    Visa, I.; Cotorcea, A.; Neagoe, M.; Moldovan, M.

    2016-08-01

    International trade of goods largely uses maritime/transoceanic ships driven by engines using fossil fuels. This two centuries tradition is technologically mature but significantly adds to the CO2 emissions; therefore, recent trends focus on on-board implementation of systems converting the solar energy into power (photovoltaic systems) or heat (solar-thermal systems). These systems are carbon-emissions free but are still under research and plenty of effort is devoted to fast reach maturity and feasibility. Unlike the systems implemented in a specific continental location, the design of solar energy conversion systems installed on shipboard has to face the problem generated by the system base motion along with the ship travelling on routes at different latitudes: the navigation direction and sense and roll-pitch combined motion with reduced amplitude, but with relatively high frequency. These raise highly interesting challenges in the design and development of mechanical systems that support the maximal output in terms of electricity or heat. The paper addresses the modelling of the relative position of a solar energy conversion surface installed on a ship according to the current position of the sun; the model is based on the navigation trajectory/route, ship motion generated by waves and the relative sun-earth motion. The model describes the incidence angle of the sunray on the conversion surface through five characteristic angles: three used to define the ship orientation and two for the solar angles; based on, their influence on the efficiency in solar energy collection is analyzed by numerical simulations and appropriate recommendations are formulated for increasing the solar energy conversion systems adaptability on ships.

  16. Engineered nanomaterials for solar energy conversion.

    Science.gov (United States)

    Mlinar, Vladan

    2013-02-01

    Understanding how to engineer nanomaterials for targeted solar-cell applications is the key to improving their efficiency and could lead to breakthroughs in their design. Proposed mechanisms for the conversion of solar energy to electricity are those exploiting the particle nature of light in conventional photovoltaic cells, and those using the collective electromagnetic nature, where light is captured by antennas and rectified. In both cases, engineered nanomaterials form the crucial components. Examples include arrays of semiconductor nanostructures as an intermediate band (so called intermediate band solar cells), semiconductor nanocrystals for multiple exciton generation, or, in antenna-rectifier cells, nanomaterials for effective optical frequency rectification. Here, we discuss the state of the art in p-n junction, intermediate band, multiple exciton generation, and antenna-rectifier solar cells. We provide a summary of how engineered nanomaterials have been used in these systems and a discussion of the open questions.

  17. Localized Oscillatory Energy Conversion in Magnetopause Reconnection

    Science.gov (United States)

    Burch, J. L.; Ergun, R. E.; Cassak, P. A.; Webster, J. M.; Torbert, R. B.; Giles, B. L.; Dorelli, J. C.; Rager, A. C.; Hwang, K.-J.; Phan, T. D.; Genestreti, K. J.; Allen, R. C.; Chen, L.-J.; Wang, S.; Gershman, D.; Le Contel, O.; Russell, C. T.; Strangeway, R. J.; Wilder, F. D.; Graham, D. B.; Hesse, M.; Drake, J. F.; Swisdak, M.; Price, L. M.; Shay, M. A.; Lindqvist, P.-A.; Pollock, C. J.; Denton, R. E.; Newman, D. L.

    2018-02-01

    Data from the NASA Magnetospheric Multiscale mission are used to investigate asymmetric magnetic reconnection at the dayside boundary between the Earth's magnetosphere and the solar wind. High-resolution measurements of plasmas and fields are used to identify highly localized ( 15 electron Debye lengths) standing wave structures with large electric field amplitudes (up to 100 mV/m). These wave structures are associated with spatially oscillatory energy conversion, which appears as alternatingly positive and negative values of J · E. For small guide magnetic fields the wave structures occur in the electron stagnation region at the magnetosphere edge of the electron diffusion region. For larger guide fields the structures also occur near the reconnection X-line. This difference is explained in terms of channels for the out-of-plane current (agyrotropic electrons at the stagnation point and guide field-aligned electrons at the X-line).

  18. Systems Engineering Model for ART Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Mendez Cruz, Carmen Margarita [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rochau, Gary E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wilson, Mollye C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    The near-term objective of the EC team is to establish an operating, commercially scalable Recompression Closed Brayton Cycle (RCBC) to be constructed for the NE - STEP demonstration system (demo) with the lowest risk possible. A systems engineering approach is recommended to ensure adequate requirements gathering, documentation, and mode ling that supports technology development relevant to advanced reactors while supporting crosscut interests in potential applications. A holistic systems engineering model was designed for the ART Energy Conversion program by leveraging Concurrent Engineering, Balance Model, Simplified V Model, and Project Management principles. The resulting model supports the identification and validation of lifecycle Brayton systems requirements, and allows designers to detail system-specific components relevant to the current stage in the lifecycle, while maintaining a holistic view of all system elements.

  19. Polymeric Materials for Conversion of Electromagnetic Waves from the Sun to Electric Power

    Directory of Open Access Journals (Sweden)

    SK Manirul Haque

    2018-03-01

    Full Text Available Solar photoelectric energy converted into electricity requires large surface areas with incident light and flexible materials to capture these light emissions. Currently, sunlight rays are converted to electrical energy using silicon polymeric material with efficiency up to 22%. The majority of the energy is lost during conversion due to an energy gap between sunlight photons and polymer energy transformation. This energy conversion also depends on the morphology of present polymeric materials. Therefore, it is very important to construct mechanisms of highest energy occupied molecular orbitals (HOMOs and the lowest energy unoccupied molecular orbitals (LUMOs to increase the efficiency of conversion. The organic and inorganic solar cells used as dyes can absorb more photons from sunlight and the energy gap will be less for better conversion of energy to electricity than the conventional solar cells. This paper provides an up-to-date review on the performance, characterization, and reliability of different composite polymeric materials for energy conversion. Specific attention has been given to organic solar cells because of their several advantages over others, such as their low-energy payback time, conversion efficiency and greenhouse emissions. Finally, this paper provides the recent progress on the application of both organic and inorganic solar cells for electric power generations together with several challenges that are currently faced.

  20. Theoretical efficiency limits for thermoradiative energy conversion

    International Nuclear Information System (INIS)

    Strandberg, Rune

    2015-01-01

    A new method to produce electricity from heat called thermoradiative energy conversion is analyzed. The method is based on sustaining a difference in the chemical potential for electron populations above and below an energy gap and let this difference drive a current through an electric circuit. The difference in chemical potential originates from an imbalance in the excitation and de-excitation of electrons across the energy gap. The method has similarities to thermophotovoltaics and conventional photovoltaics. While photovoltaic cells absorb thermal radiation from a body with higher temperature than the cell itself, thermoradiative cells are hot during operation and emit a net outflow of photons to colder surroundings. A thermoradiative cell with an energy gap of 0.25 eV at a temperature of 500 K in surroundings at 300 K is found to have a theoretical efficiency limit of 33.2%. For a high-temperature thermoradiative cell with an energy gap of 0.4 eV, a theoretical efficiency close to 50% is found while the cell produces 1000 W/m 2 has a temperature of 1000 K and is placed in surroundings with a temperature of 300 K. Some aspects related to the practical implementation of the concept are discussed and some challenges are addressed. It is, for example, obvious that there is an upper boundary for the temperature under which solid state devices can work properly over time. No conclusions are drawn with regard to such practical boundaries, because the work is aimed at establishing upper limits for ideal thermoradiative devices

  1. Standard-Cell, Open-Architecture Power Conversion Systems

    National Research Council Canada - National Science Library

    Boroyevich, D; Wang, F; Lee, F. C; Odendaal, W. G; Edwards, S

    2005-01-01

    ...). This project was purposefully aimed to develop a standardized hierarchical design and analysis methodology for modular power electronics conversion systems using as basis the ISO/OSI seven-layer reference model...

  2. Luminescent GdVO{sub 4}:Sm{sup 3+} quantum dots enhance power conversion efficiency of bulk heterojunction polymer solar cells by Förster resonance energy transfer

    Energy Technology Data Exchange (ETDEWEB)

    Bishnoi, Swati [CSIR-Network of Institutes for Solar Energy, New Delhi 110001 (India); Luminescent Materials and Devices Group, CSIR-National Physical Laboratory, New Delhi 110012 (India); Academy of Scientific and Innovative Research (AcSIR), CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Gupta, Vinay, E-mail: drvinaygupta@netscape.net; Sharma, Gauri D.; Chand, Suresh [CSIR-Network of Institutes for Solar Energy, New Delhi 110001 (India); Organic and Hybrid Solar Cells Group, Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, New Delhi 110012 (India); Sharma, Chhavi; Kumar, Mahesh [Ultrafast Optoelectronics and Terahertz Photonics Lab, Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, New Delhi 110012 (India); Haranath, D. [CSIR-Network of Institutes for Solar Energy, New Delhi 110001 (India); Luminescent Materials and Devices Group, CSIR-National Physical Laboratory, New Delhi 110012 (India); Naqvi, Sheerin [Luminescent Materials and Devices Group, CSIR-National Physical Laboratory, New Delhi 110012 (India)

    2016-07-11

    In this work, we report enhanced power conversion efficiency (PCE) of bulk heterojunction polymer solar cells by Förster resonance energy transfer (FRET) from samarium-doped luminescent gadolinium orthovanadate (GdVO{sub 4}:Sm{sup 3+}) quantum dots (QDs) to polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7) polymer. The photoluminescence emission spectrum of GdVO{sub 4}:Sm{sup 3+} QDs overlaps with the absorption spectrum of PTB7, leading to FRET from GdVO{sub 4}:Sm{sup 3+} to PTB7, and significant enhancements in the charge-carrier density of excited and polaronic states of PTB7 are observed. This was confirmed by means of femtosecond transient absorption spectroscopy. The FRET from GdVO{sub 4}:Sm{sup 3+} QDs to PTB7 led to a remarkable increase in the power conversion efficiency (PCE) of PTB7:GdVO{sub 4}:Sm{sup 3+}:PC{sub 71}BM ([6,6]-phenyl-C{sub 71}-butyric acid methyl ester) polymer solar cells. The PCE in optimized ternary blend PTB7:GdVO{sub 4}:Sm{sup 3+}:PC{sub 71}BM (1:0.1:1.5) is increased to 8.8% from 7.2% in PTB7:PC{sub 71}BM. This work demonstrates the potential of rare-earth based luminescent QDs in enhancing the PCE of polymer solar cells.

  3. An approach to the conversion of the power generated by an offshore wind power farm connected into seawave power generator

    Energy Technology Data Exchange (ETDEWEB)

    Franzitta, Vicenzo; Messineo, Antonio; Trapanese, Marco

    2011-07-01

    The development of renewable energy systems has been undergoing for the past decades but sea wave's energy resource has been under-utilized. This under-utilization has several reasons: the energy concentration is low in sea waves, extraction of this energy requires leading edge technologies and conversion of the energy into electrical energy is difficult. This study compares two different methods to connect the sea waves' generator to the network and to the offshore wind power farm. The first method consists in a decentralized approach: each generator is connected to the grid through an AC converter. The second method is a partially centralized approach: a rectifier is connected to each generator, all of the generators are then connected together to a common DC bus and power is then converted in AC to be connected to the grid. This study has shown that the partially centralized approach is more reliable and efficient than the decentralized approach.

  4. Thermodynamic limit for coherence-limited solar power conversion

    Science.gov (United States)

    Mashaal, Heylal; Gordon, Jeffrey M.

    2014-09-01

    The spatial coherence of solar beam radiation is a key constraint in solar rectenna conversion. Here, we present a derivation of the thermodynamic limit for coherence-limited solar power conversion - an expansion of Landsberg's elegant basic bound, originally limited to incoherent converters at maximum flux concentration. First, we generalize Landsberg's work to arbitrary concentration and angular confinement. Then we derive how the values are further lowered for coherence-limited converters. The results do not depend on a particular conversion strategy. As such, they pertain to systems that span geometric to physical optics, as well as classical to quantum physics. Our findings indicate promising potential for solar rectenna conversion.

  5. Overview of SOFC/SOEC development at DTU Energy Conversion

    DEFF Research Database (Denmark)

    Hagen, Anke

    2014-01-01

    According to a broad political agreement in Denmark, the Danish energy system should become independent on fossil fuels like oil, coal and natural gas by the year 2050. This aim requires expansion of electricity production from renewable sources, in particular wind mills. In order to balance...... the fluctuating power production and to cope with the discrepancies between demand and supply of power, solid oxide fuel cells and electrolysis are considered key technologies. DTU Energy Conversion has a strong record in SOFC/SOEC research, with a close collaboration with industry, in particular with Danish...... Topsoe Fuel Cell A/S. Recent achievements will be presented ranging from development of new cell generations, manufacturability, up to testing under realistic operating conditions including degradation studies and high pressure testing. A strong focus will be on development of methodologies, e...

  6. Improvements in the electromechanical conversion of energy using shock waves

    International Nuclear Information System (INIS)

    Landure, Yves

    1971-01-01

    This report concerns the electrical mechanical conversion. In this study it was obtained by the depolarization of a ferroelectric ceramic. We are particularly interested by the high electrical horse-power. Shock wave which produces depolarization is created by a gun powder. The speed of the projectile is measured and the pressures generated in the ceramic is determined graphically. The energy freed is released on a linear resistive load. We were able to prove by different parameters how to obtain the maximum electrical energy. On a resistive load of 26 ohms, it was freed 0,91 J/cm 3 in less than 0,5 μs corresponding to an electrical horse-power superior to 2 MW/cm 3 . (author) [fr

  7. Advanced Radioisotope Power Conversion Technology Research and Development

    Science.gov (United States)

    Wong, Wayne A.

    2004-01-01

    NASA's Radioisotope Power Conversion Technology program is developing next generation power conversion technologies that will enable future missions that have requirements that cannot be met by either the ubiquitous photovoltaic systems or by current Radioisotope Power System (RPS) technology. Performance goals of advanced radioisotope power systems include improvement over the state-of-practice General Purpose Heat Source/Radioisotope Thermoelectric Generator by providing significantly higher efficiency to reduce the number of radioisotope fuel modules, and increase specific power (watts/kilogram). Other Advanced RPS goals include safety, long-life, reliability, scalability, multi-mission capability, resistance to radiation, and minimal interference with the scientific payload. NASA has awarded ten contracts in the technology areas of Brayton, Stirling, Thermoelectric, and Thermophotovoltaic power conversion including five development contracts that deal with more mature technologies and five research contracts. The Advanced RPS Systems Assessment Team includes members from NASA GRC, JPL, DOE and Orbital Sciences whose function is to review the technologies being developed under the ten Radioisotope Power Conversion Technology contracts and assess their relevance to NASA's future missions. Presented is an overview of the ten radioisotope power conversion technology contracts and NASA's Advanced RPS Systems Assessment Team.

  8. Development of GT-MGR plant power conversion unit design

    International Nuclear Information System (INIS)

    Kostin, V.I.; Kodochigov, N.G.; Belov, S.E.; Vasyaev, A.V.; Golovko, V.F.; Shenoj, A.

    2007-01-01

    The General Atomic Company (USA) and the Pilot Design Bureau for Machine-Building (Russia) are involved in the efforts to design the GT-MGR modular helium cooled reactor and the energy conversion unit with the direct gas turbine cycle. The reactor capacity is equal to 600 MW, it is cooled by helium under 7 MPa pressure. The energy conversion unit consists of a gas turbine, a recuperator, preliminary and intermediate coolers, a generator. The turbine shaft rotation frequency is equal to 4400 rotation/minute. One analyzed the alternate designs of the energy conversion unit to choose its configuration [ru

  9. Tandem photovoltaic solar cells and increased solar energy conversion efficiency

    Science.gov (United States)

    Loferski, J. J.

    1976-01-01

    Tandem photovoltaic cells, as proposed by Jackson (1955) to increase the efficiency of solar energy conversion, involve the construction of a system of stacked p/n homojunction photovoltaic cells composed of different semiconductors. It had been pointed out by critics, however, that the total power which could be extracted from the cells in the stack placed side by side was substantially greater than the power obtained from the stacked cells. A reexamination of the tandem cell concept in view of the development of the past few years is conducted. It is concluded that the use of tandem cell systems in flat plate collectors, as originally envisioned by Jackson, may yet become feasible as a result of the development of economically acceptable solar cells for large scale terrestrial power generation.

  10. Supercritical Carbon Dioxide Brayton Cycle Energy Conversion System

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Jae Eun; Kim, S. O.; Seong, S. H.; Eoh, J. H.; Lee, T. H.; Choi, S. K.; Han, J. W.; Bae, S. W

    2007-12-15

    This report contains the description of the S-CO{sub 2} Brayton cycle coupled to KALIMER-600 as an alternative energy conversion system. For system development, a computer code was developed to calculate heat balance of 100% power operation condition. Based on the computer code, the S-CO{sub 2} Brayton cycle energy conversion system was constructed for the KALIMER-600. Using the developed turbomachinery models, the off-design characteristics and the sensitivities of the S-CO{sub 2} turbomachinery were investigated. For the development of PCHE models, a one-dimensional analysis computer code was developed to evaluate the performance of the PCHE. Possible control schemes for power control in the KALIMER-600 S-CO{sub 2} Brayton cycle were investigated by using the MARS code. Simple power reduction and recovery event was selected and analyzed for the transient calculation. For the evaluation of Na/CO{sub 2} boundary failure event, a computer was developed to simulate the complex thermodynamic behaviors coupled with the chemical reaction between liquid sodium and CO{sub 2} gas. The long term behavior of a Na/CO{sub 2} boundary failure event and its consequences which lead to a system pressure transient were evaluated.

  11. Supercritical Carbon Dioxide Brayton Cycle Energy Conversion System

    International Nuclear Information System (INIS)

    Cha, Jae Eun; Kim, S. O.; Seong, S. H.; Eoh, J. H.; Lee, T. H.; Choi, S. K.; Han, J. W.; Bae, S. W.

    2007-12-01

    This report contains the description of the S-CO 2 Brayton cycle coupled to KALIMER-600 as an alternative energy conversion system. For system development, a computer code was developed to calculate heat balance of 100% power operation condition. Based on the computer code, the S-CO 2 Brayton cycle energy conversion system was constructed for the KALIMER-600. Using the developed turbomachinery models, the off-design characteristics and the sensitivities of the S-CO 2 turbomachinery were investigated. For the development of PCHE models, a one-dimensional analysis computer code was developed to evaluate the performance of the PCHE. Possible control schemes for power control in the KALIMER-600 S-CO 2 Brayton cycle were investigated by using the MARS code. Simple power reduction and recovery event was selected and analyzed for the transient calculation. For the evaluation of Na/CO 2 boundary failure event, a computer was developed to simulate the complex thermodynamic behaviors coupled with the chemical reaction between liquid sodium and CO 2 gas. The long term behavior of a Na/CO 2 boundary failure event and its consequences which lead to a system pressure transient were evaluated

  12. Hybrid acoustic energy harvesting using combined electromagnetic and piezoelectric conversion

    Science.gov (United States)

    Khan, Farid Ullah; Izhar

    2016-02-01

    This paper reports a novel hybrid acoustic energy harvester. The harvester utilizes both the electromagnetic and piezoelectric conversion mechanisms simultaneously to convert the ambient acoustical noise into electrical power for self-powered wireless sensor nodes. The proposed harvester is comprised of a Helmholtz resonator, two magnets mounted on a piezoelectric plate, and a wound coil located under the magnets. The harvester is characterized both under harmonic and real random acoustical excitations. In-lab, under harmonic acoustical excitation at a sound pressure level of 130 dB and frequency of 2.1 kHz, an optimum power of 2.86 μW (at 114 Ω optimum load) is obtained from electromagnetic conversion and 50 μW (at 1000 Ω optimum load) is generated by the piezoelectric harvester's part. Moreover, in real acoustical environment of a domestic electric generator the peak voltages of 40 and 123 mV are produced by the electromagnetic and piezoelectric portions of the acoustic energy harvester.

  13. The Carbon Nanotube Fibers for Optoelectric Conversion and Energy Storage

    Directory of Open Access Journals (Sweden)

    Yongfeng Luo

    2014-01-01

    Full Text Available This review summarizes recent studies on carbon nanotube (CNT fibers for weavable device of optoelectric conversion and energy storage. The intrinsic properties of individual CNTs make the CNT fibers ideal candidates for optoelectric conversion and energy storage. Many potential applications such as solar cell, supercapacitor, and lithium ion battery have been envisaged. The recent advancement in CNT fibers for optoelectric conversion and energy storage and the current challenge including low energy conversion efficiency and low stability and future direction of the energy fiber have been finally summarized in this paper.

  14. Analysis of dynamic effects in solar thermal energy conversion systems

    Science.gov (United States)

    Hamilton, C. L.

    1978-01-01

    The paper examines a study the purpose of which is to assess the performance of solar thermal power systems insofar as it depends on the dynamic character of system components and the solar radiation which drives them. Using a dynamic model, the daily operation of two conceptual solar conversion systems was simulated under varying operating strategies and several different time-dependent radiation intensity functions. These curves ranged from smoothly varying input of several magnitudes to input of constant total energy whose intensity oscillated with periods from 1/4 hour to 6 hours.

  15. Iron disulfide for solar energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Ennaoui, A. (Hahn-Meitner-Inst., Abt. Solare Energetik und Materialforschung, Berlin (Germany)); Fiechter, S. (Hahn-Meitner-Inst., Abt. Solare Energetik und Materialforschung, Berlin (Germany)); Pettenkofer, C. (Hahn-Meitner-Inst., Abt. Solare Energetik und Materialforschung, Berlin (Germany)); Alonso-Vante, N. (Hahn-Meitner-Inst., Abt. Solare Energetik und Materialforschung, Berlin (Germany)); Bueker, K. (Hahn-Meitner-Inst., Abt. Solare Energetik und Materialforschung, Berlin (Germany)); Bronold, M. (Hahn-Meitner-Inst., Abt. Solare Energetik und Materialforschung, Berlin (Germany)); Hoepfner, C. (Hahn-Meitner-Inst., Abt. Solare Energetik und Materialforschung, Berlin (Germany)); Tributsch, H. (Hahn-Meitner-Inst., Abt. Solare Energetik und Materialforschung, Berlin (Germany))

    1993-05-01

    Pyrite (E[sub g] = 0.95 eV) is being developed as a solar energy material due to its environmental compatibility and its very high light absorption coefficient. A compilation of material, electronic and interfacial chemical properties is presented, which is considered relevant for quantum energy conversion. In spite of intricate problems existing within material chemistry, high quantum efficiencies for photocurrent generation (> 90%) and high photovoltages ([approx] 500 mV) have been observed with single crystal electrodes and thin layers respectively. The most interesting aspect of this study is the use of pyrite as an ultrathin (10-20 nm) layer sandwiched between large gap p-type and n-type materials in a p-i-n like structure. Such a system, in which the pyrite layer only acts as photon absorber and mediates injection of excited electrons can be defined as sensitization solar cell. The peculiar electron transfer properties of pyrite interfaces, facilitating interfacial coordination chemical pathways, may turn out to be very helpful. Significant research challenges are discussed in the hope of attracting interest in the development of solar cells from this abundant material. (orig.)

  16. Photovoltaic conversion of the solar energy

    International Nuclear Information System (INIS)

    Gordillo G, Gerardo

    1998-01-01

    In this work, a short description of the basic aspect of the performance of homojunction solar cells and of the technological aspects of the fabrication of low cost thin film solar cells is made. Special emphasis on the historical aspects of the evolution of the conversion efficiency of photovoltaic devices based on crystalline silicon, amorphous silicon, Cd Te and CulnSe 2 is also made. The state of art of the technology of photovoltaic devices and modules is additionally presented. The contribution to the development of high efficiency solar cells and modules, carried out by research centers of universities such us: Stuttgart university (Germany), Stockholm university (Sweden), University of South Florida (USA), university of south gales (Australia), by the national renewable energy laboratory of USA and by research centers of companies such us: Matsushita (Japan), BP-solar (England), Boeing (USA), Arco solar (USA), Siemens (Germany) etc. are specially emphasized. Additionally, a section concerning economical aspect of the photovoltaic generation of electric energy is enclosed. In this section an overview of the evolution of price and world market of photovoltaic system is presented

  17. An efficiency booster for energy conversion in natural circulation loops

    International Nuclear Information System (INIS)

    Wang, Dongqing; Jiang, Jin

    2016-01-01

    Highlights: • Low driving power conversion efficiency of natural circulation loops is proved. • The low conversion efficiency leads to low heat transfer capacity of such loops. • An efficiency booster is designed with turbine to increase the efficiency. • Performance of the proposed booster has been numerically simulated. • The booster drastically enhances heat transfer capacity of such loops. - Abstract: In this paper, the capacity of a natural circulation loop for transferring heat from a heat source to a heat sink has been analyzed. It is concluded that the capacity of the natural circulation loop depends on the conversion efficiency of the thermal energy from the heat source to the driving force for the circulation of the flow. The low conversion efficiency leading to weak driving force in such loops has been demonstrated analytically and validated through simulation results. This issue has resulted in a low heat transfer capacity in the circulation loop. To increase the heat transfer capacity, one has to improve this efficiency. To meet such a need, a novel efficiency booster has been developed in this paper. The booster essentially increases the flow driving force and hence significantly improves the overall heat transfer capacity. Design and analysis of this booster have been performed in detail. The performance has been examined through extensive computer simulations. It is concluded that the booster can indeed drastically improve the heat transfer capacity of the natural circulation loop.

  18. An efficiency booster for energy conversion in natural circulation loops

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dongqing, E-mail: wangdongqing@stu.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Beijing Computational Science Research Center, Beijing 100084 (China); Jiang, Jin, E-mail: jjiang@eng.uwo.ca [Department of Electrical and Computer Engineering, The University of Western Ontario, London, Ontario N6A 5B9 (Canada); Beijing Computational Science Research Center, Beijing 100084 (China)

    2016-08-01

    Highlights: • Low driving power conversion efficiency of natural circulation loops is proved. • The low conversion efficiency leads to low heat transfer capacity of such loops. • An efficiency booster is designed with turbine to increase the efficiency. • Performance of the proposed booster has been numerically simulated. • The booster drastically enhances heat transfer capacity of such loops. - Abstract: In this paper, the capacity of a natural circulation loop for transferring heat from a heat source to a heat sink has been analyzed. It is concluded that the capacity of the natural circulation loop depends on the conversion efficiency of the thermal energy from the heat source to the driving force for the circulation of the flow. The low conversion efficiency leading to weak driving force in such loops has been demonstrated analytically and validated through simulation results. This issue has resulted in a low heat transfer capacity in the circulation loop. To increase the heat transfer capacity, one has to improve this efficiency. To meet such a need, a novel efficiency booster has been developed in this paper. The booster essentially increases the flow driving force and hence significantly improves the overall heat transfer capacity. Design and analysis of this booster have been performed in detail. The performance has been examined through extensive computer simulations. It is concluded that the booster can indeed drastically improve the heat transfer capacity of the natural circulation loop.

  19. Nanostructured Solar Irradiation Control Materials for Solar Energy Conversion

    Science.gov (United States)

    Kang, Jinho; Marshall, I. A.; Torrico, M. N.; Taylor, C. R.; Ely, Jeffry; Henderson, Angel Z.; Kim, J.-W.; Sauti, G.; Gibbons, L. J.; Park, C.; hide

    2012-01-01

    Tailoring the solar absorptivity (alpha(sub s)) and thermal emissivity (epsilon(sub T)) of materials constitutes an innovative approach to solar energy control and energy conversion. Numerous ceramic and metallic materials are currently available for solar absorbance/thermal emittance control. However, conventional metal oxides and dielectric/metal/dielectric multi-coatings have limited utility due to residual shear stresses resulting from the different coefficient of thermal expansion of the layered materials. This research presents an alternate approach based on nanoparticle-filled polymers to afford mechanically durable solar-absorptive and thermally-emissive polymer nanocomposites. The alpha(sub s) and epsilon(sub T) were measured with various nano inclusions, such as carbon nanophase particles (CNPs), at different concentrations. Research has shown that adding only 5 wt% CNPs increased the alpha(sub s) and epsilon(sub T) by a factor of about 47 and 2, respectively, compared to the pristine polymer. The effect of solar irradiation control of the nanocomposite on solar energy conversion was studied. The solar irradiation control coatings increased the power generation of solar thermoelectric cells by more than 380% compared to that of a control power cell without solar irradiation control coatings.

  20. Advances in Very High Frequency Power Conversion

    DEFF Research Database (Denmark)

    Kovacevic, Milovan

    Resonant and quasi-resonant converters operated at frequencies above 30 MHz have attracted special attention in the last two decades. Compared to conventional converters operated at ~100 kHz, they offer significant advantages: smaller volume and weight, lower cost, and faster transient performance....... Excellent performance and small size of magnetic components and capacitors at very high frequencies, along with constant advances in performance of power semiconductor devices, suggests a sizable shift in consumer power supplies market into this area in the near future. To operate dc-dc converter power...... method provides low complexity and low gate loss simultaneously. A direct design synthesis method is provided for resonant SEPIC converters employing this technique. Most experimental prototypes were developed using low cost, commercially available power semiconductors. Due to very fast transient...

  1. Modeling on a PWR power conversion system with system program

    International Nuclear Information System (INIS)

    Gao Rui; Yang Yanhua; Lin Meng

    2007-01-01

    Based on the power conversion system of nuclear and conventional islands of Daya Bay Power Station, this paper models the thermal-hydraulic systems of primary and secondary loops for PWR by using the PWR best-estimate program-RELAP5. To simulate the full-scope power conversion system, not only the traditional basic system models of nuclear island, but also the major system models of conventional island are all considered and modeled. A comparison between the calculated results and the actual data of reactor demonstrates a fine match for Daya Bay Nuclear Power Station, and manifests the feasibility in simulating full-scope power conversion system of PWR by RELAP5 at the same time. (authors)

  2. Direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify design, increase efficiency and integration level, reduce product volume and lower its cost. As an example, the principle of operation and the measurements made on a direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp are presented. (au)

  3. Energy Conversion in Imploding Z-Pinch Plasma

    International Nuclear Information System (INIS)

    Fisher, V.I.; Gregorian, L.; Davara, G.; Kroupp, E.; Bernshtam, V.A.; Ralchenko, Yu. V.; Starobinets, A.; Maron, Y.

    2002-01-01

    Due to important applications, Z-pinches became a subject of extensive studies. In these studies, main attention is directed towards improvement in efficiency of electric energy conversion into high-power radiation burst. At present, knowledge available on physics of Z-pinch operation, plasma motion, atomic kinetics, and energy conversion is mainly knowledge of numerical simulation results. We believe further progress require (i) experimental determination of spatial distribution and time history of thermodynamic parameters and magnetic field, as well as (ii) utilization of this data for experiment-based calculation of r,t-distribution of driving forces, mass and energy fluxes, and local energy deposition rates due to each of contributing mechanisms, what provides an insight into a process of conversion of stored electric energy into radiation burst. Moreover, experimentally determined r, t-distribution of parameters may serve for verification of computer programs developed for simulation of Z-pinch operation and optimization of radiation output. Within this research program we performed detailed spectroscopic study of plasmas imploding in modest-size (25 kV, 5 kJ, 1.2 μs quaterperiod) gas-puff Z-pinch. This facility has reasonably high repetition rate and provides good reproducibility of results. Consistent with plasma ionization degree in the implosion period, measurements are performed in UV-visible spectral range. Observation of spectral lines emitted at various azimuthal angles f showed no dependence on f. Dependence on axial coordinate z is found to be weak in near-anode half of the anode-cathode gap. Based on these observations and restricting the measurements to near-anode half of the gap, an evolution of parameters is studied in time and radial coordinate r only. In present talk we report on determination of radial component of plasma hydrodynamic velocity u r (r,t), magnetic field B ζ (r,t), electron density n e (r,t), density of ions in various

  4. Direct energy conversion of radiation energy in fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S. [National Inst. for Fusion Science, Nagoya (Japan); Ohnishi, M.; Onozuka, M.; Uenosono, C.

    1994-12-31

    Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generate electricity by temperature gradient in conductors. A Strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy converter are mentioned. (author).

  5. Direct energy conversion of radiation energy in fusion reactor

    International Nuclear Information System (INIS)

    Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

    1994-01-01

    Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generate electricity by temperature gradient in conductors. A Strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy converter are mentioned. (author)

  6. 2nd Workshop on the Chemistry of Energy Conversion

    CERN Document Server

    2016-01-01

    A sustainable energy future that does not rely on fossil fuels requires the advances of new materials design and development with efficient energy conversion. However, materials development is still at its infancy. There is an imperative to develop new energy conversion strategies. In Nature, plants harness sunlight and convert them into chemical energy. The ability to mimic Nature by combining synthetic nanoscopic and molecular components to produce chemical fuels is the Holy Grail to achieve sustainable energy production.​ The Institute of Advanced Studies (IAS) and the School of Physical and Mathematical Sciences (SPMS), NTU, are jointly organizing this workshop. We aim to create dialogues among scientists in the energy conversion field, with the ultimate goal of facilitating breakthroughs in materials design for energy conversion. It will also bring the expertise on Chemistry of Energy Conversion to the door steps of the materials research community in Singapore and also provide a platform for partic...

  7. Demonstrating Energy Conversion with Piezoelectric Crystals and a Paddle Fan

    Science.gov (United States)

    Rakbamrung, Prissana; Putson, Chatchai; Muensit, Nantakan

    2014-01-01

    A simple energy conversion system--particularly, the conversion of mechanical energy into electrical energy by using shaker flashlights--has recently been presented. This system uses hand generators, consisting of a magnet in a tube with a coil wrapped around it, and acts as an ac source when the magnet passes back and forth through the coil.…

  8. Direct energy conversion for IEC fusion for space applications

    International Nuclear Information System (INIS)

    Momota, Hiromu; Nadler, Jon; Miley, George H.

    2000-08-01

    The paper describes a concept of extracting fusion power from D- 3 He fueled IEC (Inertia Electrostatic Configuration) devices. The fusion system consists of a series of fusion modules and direct energy converters at an end or at both ends. This system of multiple units is linear and is connected by a magnetic field. A pair of coils anti-parallel to the magnetic field yields a field-null domain at the center of each unit as required for IEC operation. A stabilizing coil installed between the coil pairs eliminates the strong attractive force between the anti-parallel coils. Accessible regions for charged particle trajectories are essentially isolated from the coil structure. Thus, charged particles are directed along magnetic field lines to the direct energy converter without appreciable losses. A direct energy converter unit designed to be compatible to this unique system is also described. It basically consists of a separator and a traveling wave converter. A separator separates low energy ions and electron from the 14.7 MeV fusion protons and then converts their energy into electricity. In the traveling wave direct energy converter, fusion protons are modulated to form bunches. It couples with a transmission line to couple AC power out. The overall conversion efficiency of this system, combined with E- 3 He IEC cores, is estimated as high as 60%. (author)

  9. Direct energy conversion for IEC fusion for space applications

    Energy Technology Data Exchange (ETDEWEB)

    Momota, Hiromu; Nadler, Jon [National Inst. for Fusion Science, Toki, Gifu (Japan); Miley, George H. [Fusion Studies Laboratory, Urbana, IL (United States)

    2000-08-01

    The paper describes a concept of extracting fusion power from D-{sup 3}He fueled IEC (Inertia Electrostatic Configuration) devices. The fusion system consists of a series of fusion modules and direct energy converters at an end or at both ends. This system of multiple units is linear and is connected by a magnetic field. A pair of coils anti-parallel to the magnetic field yields a field-null domain at the center of each unit as required for IEC operation. A stabilizing coil installed between the coil pairs eliminates the strong attractive force between the anti-parallel coils. Accessible regions for charged particle trajectories are essentially isolated from the coil structure. Thus, charged particles are directed along magnetic field lines to the direct energy converter without appreciable losses. A direct energy converter unit designed to be compatible to this unique system is also described. It basically consists of a separator and a traveling wave converter. A separator separates low energy ions and electron from the 14.7 MeV fusion protons and then converts their energy into electricity. In the traveling wave direct energy converter, fusion protons are modulated to form bunches. It couples with a transmission line to couple AC power out. The overall conversion efficiency of this system, combined with E-{sup 3}He IEC cores, is estimated as high as 60%. (author)

  10. Biological conversion of hydrogen to electricity for energy storage

    International Nuclear Information System (INIS)

    Karamanev, Dimitre; Pupkevich, Victor; Penev, Kalin; Glibin, Vassili; Gohil, Jay; Vajihinejad, Vahid

    2017-01-01

    Energy storage is currently one of the most significant problems associated with mass-scale usage of renewable (i.e. wind and solar) power sources. The use of hydrogen as an energy storage medium is very promising, but is hampered by the lack of commercially available hydrogen-to-electricity (H2e) converters. Here we are presenting the first commercially viable, biologically based technology for H2e conversion named the BioGenerator. It is a microbial fuel cell based on electron consumption resulting from the respiration of chemolithoautotrophic microorganisms. The results obtained during the scale-up study of the BioGenerator showed a maximum specific current of 1.35 A/cm 2 , maximum power density of 1800 W/m 2 and stable electricity generation over a period spanning longer than four years. The largest unit studied so far has a volume of 600 L and a power output of 0.3 kW. - Highlights: • A commercially viable biological convertor of H 2 to electricity (BioGenerator) is proposed. • It has a short-term commercial potential and its economic analysis is quite promising. • The BioGenerator is the first commercially viable bio-technology for energy storage. • It is a power generation technology of which has a negative CO 2 emission.

  11. Nano-materials for solar energy conversion

    International Nuclear Information System (INIS)

    Davenas, J.; Boiteux, G.; Ltaief, A.; Barlier, V.

    2006-01-01

    Nano-materials present an important development potential in the field of photovoltaic conversion in opening new outlooks in the reduction of the solar energy cost. The organic or hybrid solar cells principle is based on the electron-hole pairs dissociation, generated under solar radiation on a conjugated polymer, by chemical species acting as electrons acceptors. The two ways based on fullerenes dispersion or on TiO 2 particles in a semi-conductor polymer (MEH-PPV, PVK) are discussed. The acceptors concentration is high in order to allow the conduction of the electrons on a percolation way, the polymer providing the holes conduction. A new preparation method of the mixtures MEH-PPV/fullerenes based on the use of specific solvents has allowed to produce fullerenes having nano-metric sizes ranges. It has then been possible to decrease the fullerenes concentration allowing the dissociation and the transport of photoinduced charges. The way based on the in-situ generation of TiO 2 from an organometallic precursor has allowed to obtain dispersions of nano-metric inorganic particles. The optimization of the photovoltaic properties of these nano-composites requires a particular adjustment of their composition and size ranges leading to a better control of the synthesis processes. (O.M.)

  12. Investigation of rectenna for microwave power conversion

    International Nuclear Information System (INIS)

    Karimov, Kh S; Saleem, M; Shah, M; Shafique, S

    2010-01-01

    This paper presents the fabrication of organic semiconductor (OS) rectifiers and an investigation of rectifying antenna (rectenna) under the effect of microwave power. As a source of microwaves, a patch antenna fed by a generator was used. The rectenna contains a built-in rectifier. The surface-type Ag/NiPc/Au cell, with organic semiconductor nickel phthalocyanine (NiPc) as the active material, was used as a rectenna. The rectifier was fabricated by thermal deposition of Ag, Au and NiPc thin films on thoroughly cleaned glass substrate. The measured I–V characteristics of the cell showed rectifying behavior. The rectenna was tested at frequency ranges of 8–16 GHz at different intensities of radiation and vertical and horizontal positions of the rectenna's axes. Under the effect of microwave power at the output of the rectenna, the output dc voltage and current were detected

  13. Proceedings of the Chernobyl phytoremediation and biomass energy conversion workshop

    International Nuclear Information System (INIS)

    Hartley, J.; Tokarevsky, V.

    1998-06-01

    Many concepts, systems, technical approaches, technologies, ideas, agreements, and disagreements were vigorously discussed during the course of the 2-day workshop. The workshop was successful in generating intensive discussions on the merits of the proposed concept that includes removal of radionuclides by plants and trees (phytoremediation) to clean up soil in the Chernobyl Exclusion Zone (CEZ), use of the resultant biomass (plants and trees) to generate electrical power, and incorporation of ash in concrete casks to be used as storage containers in a licensed repository for low-level waste. Twelve years after the Chernobyl Nuclear Power Plant (ChNPP) Unit 4 accident, which occurred on April 26, 1986, the primary 4radioactive contamination of concern is from radioactive cesium ( 137 Cs) and strontium ( 90 Sr). The 137 Cs and 90 Sr were widely distributed throughout the CEZ. The attendees from Ukraine, Russia, Belarus, Denmark and the US provided information, discussed and debated the following issues considerably: distribution and characteristics of radionuclides in CEZ; efficacy of using trees and plants to extract radioactive cesium (Cs) and strontium (Sr) from contaminated soil; selection of energy conversion systems and technologies; necessary infrastructure for biomass harvesting, handling, transportation, and energy conversion; radioactive ash and emission management; occupational health and safety concerns for the personnel involved in this work; and economics. The attendees concluded that the overall concept has technical and possibly economic merits. However, many issues (technical, economic, risk) remain to be resolved before a viable commercial-scale implementation could take place

  14. Proceedings of the Chornobyl phytoremediation and biomass energy conversion workshop

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, J. [Pacific Northwest National Lab., Richland, WA (United States); Tokarevsky, V. [State Co. for Treatment and Disposal of Mixed Hazardous Waste (Ukraine)

    1998-06-01

    Many concepts, systems, technical approaches, technologies, ideas, agreements, and disagreements were vigorously discussed during the course of the 2-day workshop. The workshop was successful in generating intensive discussions on the merits of the proposed concept that includes removal of radionuclides by plants and trees (phytoremediation) to clean up soil in the Chornobyl Exclusion Zone (CEZ), use of the resultant biomass (plants and trees) to generate electrical power, and incorporation of ash in concrete casks to be used as storage containers in a licensed repository for low-level waste. Twelve years after the Chornobyl Nuclear Power Plant (ChNPP) Unit 4 accident, which occurred on April 26, 1986, the primary 4radioactive contamination of concern is from radioactive cesium ({sup 137}Cs) and strontium ({sup 90}Sr). The {sup 137}Cs and {sup 90}Sr were widely distributed throughout the CEZ. The attendees from Ukraine, Russia, Belarus, Denmark and the US provided information, discussed and debated the following issues considerably: distribution and characteristics of radionuclides in CEZ; efficacy of using trees and plants to extract radioactive cesium (Cs) and strontium (Sr) from contaminated soil; selection of energy conversion systems and technologies; necessary infrastructure for biomass harvesting, handling, transportation, and energy conversion; radioactive ash and emission management; occupational health and safety concerns for the personnel involved in this work; and economics. The attendees concluded that the overall concept has technical and possibly economic merits. However, many issues (technical, economic, risk) remain to be resolved before a viable commercial-scale implementation could take place.

  15. Conversion of zero point energy into high-energy photons

    Energy Technology Data Exchange (ETDEWEB)

    Ivlev, B. I. [Universidad Autonoma de San Luis Potosi, Instituto de Fisica, Av. Manuel Nava No. 6, Zona Universitaria, 78290 San Luis Potosi, SLP (Mexico)

    2016-11-01

    An unusual phenomenon, observed in experiments is studied. X-ray laser bursts of keV energy are emitted from a metal where long-living states, resulting in population inversion, are totally unexpected. Anomalous electron-photon states are revealed to be formed inside the metal. These states are associated with narrow, 10{sup -11} cm, potential well created by the local reduction of zero point electromagnetic energy. In contrast to analogous van der Waals potential well, leading to attraction of two hydrogen atoms, the depth of the anomalous well is on the order of 1 MeV. The states in that well are long-living which results in population inversion and subsequent laser generation observed. The X-ray emission, occurring in transitions to lower levels, is due to the conversion of zero point electromagnetic energy. (Author)

  16. Wind Energy Conversion by Plant-Inspired Designs.

    Science.gov (United States)

    McCloskey, Michael A; Mosher, Curtis L; Henderson, Eric R

    2017-01-01

    In 2008 the U.S. Department of Energy set a target of 20% wind energy by 2030. To date, induction-based turbines form the mainstay of this effort, but turbines are noisy, perceived as unattractive, a potential hazard to bats and birds, and their height hampers deployment in residential settings. Several groups have proposed that artificial plants containing piezoelectric elements may harvest wind energy sufficient to contribute to a carbon-neutral energy economy. Here we measured energy conversion by cottonwood-inspired piezoelectric leaves, and by a "vertical flapping stalk"-the most efficient piezo-leaf previously reported. We emulated cottonwood for its unusually ordered, periodic flutter, properties conducive to piezo excitation. Integrated over 0°-90° (azimuthal) of incident airflow, cottonwood mimics outperformed the vertical flapping stalk, but they produced < daW per conceptualized tree. In contrast, a modest-sized cottonwood tree may dissipate ~ 80 W via leaf motion alone. A major limitation of piezo-transduction is charge generation, which scales with capacitance (area). We thus tested a rudimentary, cattail-inspired leaf with stacked elements wired in parallel. Power increased systematically with capacitance as expected, but extrapolation to acre-sized assemblages predicts < daW. Although our results suggest that present piezoelectric materials will not harvest mid-range power from botanic mimics of convenient size, recent developments in electrostriction and triboelectric systems may offer more fertile ground to further explore this concept.

  17. Advanced energy utilization MHD power generation

    International Nuclear Information System (INIS)

    2008-01-01

    The 'Technical Committee on Advanced Energy Utilization MHD Power Generation' was started to establish advanced energy utilization technologies in Japan, and has been working for three years from June 2004 to May 2007. This committee investigated closed cycle MHD, open cycle MHD, and liquid metal MHD power generation as high-efficiency power generation systems on the earth. Then, aero-space application and deep space exploration technologies were investigated as applications of MHD technology. The spin-off from research and development on MHD power generation such as acceleration and deceleration of supersonic flows was expected to solve unstart phenomena in scramjet engine and also to solve abnormal heating of aircrafts by shock wave. In addition, this committee investigated researches on fuel cells, on secondary batteries, on connection of wind power system to power grid, and on direct energy conversion system from nuclear fusion reactor for future. The present technical report described results of investigations by the committee. (author)

  18. Combustion and direct energy conversion inside a micro-combustor

    International Nuclear Information System (INIS)

    Lei, Yafeng; Chen, Wei; Lei, Jiang

    2016-01-01

    Highlights: • The flammability range of micro-combustor was broadened with heat recirculation. • The quenching diameter decreased with heat recirculation compared to without recirculation. • The surface areas to volume ratio was the most important parameter affecting the energy conversion efficiency. • The maximum conversion efficiency (3.15%) was achieved with 1 mm inner diameter. - Abstract: Electrical energy can be generated by employing a micro-thermophotovoltaic (TPV) cell which absorbs thermal radiation from combustion taking place in a micro-combustor. The stability of combustion in a micro-combustor is essential for operating a micro-power system using hydrogen and hydrocarbon fuels as energy source. To understand the mechanism of sustaining combustion within the quenching distance of fuel, this study proposed an annular micro combustion tube with recirculation of exhaust heat. To explore the feasibility of combustion in the micro annular tube, the parameters influencing the combustion namely, quenching diameter, and flammability were studied through numerical simulation. The results indicated that combustion could be realized in micro- combustor using heat recirculation. Following results were obtained from simulation. The quenching diameter reduced from 1.3 mm to 0.9 mm for heat recirculation at equivalence ratio of 1; the lean flammability was 2.5%–5% lower than that of without heat recirculation for quenching diameters between 2 mm and 5 mm. The overall energy conversion efficiency varied at different inner diameters. A maximum efficiency of 3.15% was achieved at an inner diameter of 1 mm. The studies indicated that heat recirculation is an effective strategy to maintain combustion and to improve combustion limits in micro-scale system.

  19. Embedded Solenoid Transformer for Power Conversion

    DEFF Research Database (Denmark)

    2015-01-01

    A resonant power converter for operation in the radio frequency range, preferably in the VHF, comprises at least one PCB-embedded transformer. The transformer is configured for radio frequency operation and comprises a printed circuit board defining a horizontal plane, the printed circuit board...... comprising at least two horizontal conductive layers separated by an isolating layer, a first embedded solenoid forming a primary winding of the transformer and a second embedded solenoid being arranged parallel to the first solenoid and forming a secondary winding of the transformer, wherein the first...

  20. Modeling of large aperture third harmonic frequency conversion of high power Nd:glass laser systems

    International Nuclear Information System (INIS)

    Henesian, M.A.; Wegner, P.J.; Speck, D.R.; Bibeau, C.; Ehrlich, R.B.; Laumann, C.W.; Lawson, J.K.; Weiland, T.L.

    1991-01-01

    To provide high-energy, high-power beams at short wavelengths for inertial-confinement-fusion experiments, we routinely convert the 1.053-μm output of the Nova, Nd:phosphate-glass, laser system to its third-harmonic wavelength. We describe performance and conversion efficiency modeling of the 3 x 3 arrays potassium-dihydrogen-phosphate crystal plates used for type II/type II phase-matched harmonic conversion of Nova 0.74-m diameter beams, and an alternate type I/type II phase-matching configuration that improves the third-harmonic conversion efficiency. These arrays provide energy conversion of up to 65% and intensity conversion to 70%. 19 refs., 11 figs

  1. Development of methodology for assessment of absorbed dose and stopping power for low energy conversion electrons; Desenvolvimento de uma metodologia para estimativa da dose absorvida e do poder de freamento para eletrons de conversao de baixa energia

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Ivan Pedro Salati de

    1995-08-01

    The evaluation of absorbed dose in the case of external and internalcontamination due to radionuclides is sometimes hard, because of the difficulties in the assessment of the absorbed dose caused by electrons with energy less than 100 KeV in mucous membrane. In this work, a methodology for assessment of absorbed dose and stopping power in VYNS (co-polymer of polivinyl chloride - acetate) absorbers, for the 62.5 KeV and 84-88 KeV energy {sup 109} Cd conversion electrons, working with a 4 {pi} proportional pressurized detector, is presented. In order to assure the reproducibility of measurement conditions, one of the detector halves has been used to obtain a spectrum of a thin {sup 109} Cd source, without absorber. The other half of the detector was used in concomitance to obtain spectra with different thicknesses if absorber. The absorbed energy was obtained subtracting each spectrum with absorber from the spectrum without absorber, which were stored in a microcomputer connected to signal processing systems by ACE type interface. The VYNS weight and thickness were evaluated using common radionuclide metrology procedures. As VYNS has characteristics similar to a tissue equivalent material, the results obtained are consistent with dosimetric concepts and have a good agreement with those of the literature. (author)

  2. 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)

  3. Improper ferroelectrics as high-efficiency energy conversion materials

    Energy Technology Data Exchange (ETDEWEB)

    Wakamatsu, Toru; Tanabe, Kenji; Terasaki, Ichiro; Taniguchi, Hiroki [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

    2017-05-15

    An improper ferroelectric is a certain type of ferroelectrics whose primary order parameter is not polarization but another physical quantity such as magnetization. In contrast to a conventional proper ferroelectrics as represented by Pb(Zr,Ti)O{sub 3} and BaTiO{sub 3}, the improper ferroelectrics has been inconceivable for practical applications thus far. Herein, we illustrate the great potential of improper ferroelectrics for efficient conversion of temperature fluctuation to electric energy, as demonstrated with (Ca{sub 0.84}Sr{sub 0.16}){sub 8}[AlO{sub 2}]{sub 12}(MoO{sub 4}){sub 2} (CSAM-16). The present study has experimentally proven that CSAM-16 achieves an excellent electrothermal coupling factor and high electric field sensitivity for pyroelectric energy conversion that approach a practical level for application to self-powered autonomous electronic devices for rapidly spreading wireless sensor networks. The present results provide a novel approach to developing innovative pyroelectric energy harvesting devices using improper ferroelectrics. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Improper ferroelectrics as high-efficiency energy conversion materials

    International Nuclear Information System (INIS)

    Wakamatsu, Toru; Tanabe, Kenji; Terasaki, Ichiro; Taniguchi, Hiroki

    2017-01-01

    An improper ferroelectric is a certain type of ferroelectrics whose primary order parameter is not polarization but another physical quantity such as magnetization. In contrast to a conventional proper ferroelectrics as represented by Pb(Zr,Ti)O_3 and BaTiO_3, the improper ferroelectrics has been inconceivable for practical applications thus far. Herein, we illustrate the great potential of improper ferroelectrics for efficient conversion of temperature fluctuation to electric energy, as demonstrated with (Ca_0_._8_4Sr_0_._1_6)_8[AlO_2]_1_2(MoO_4)_2 (CSAM-16). The present study has experimentally proven that CSAM-16 achieves an excellent electrothermal coupling factor and high electric field sensitivity for pyroelectric energy conversion that approach a practical level for application to self-powered autonomous electronic devices for rapidly spreading wireless sensor networks. The present results provide a novel approach to developing innovative pyroelectric energy harvesting devices using improper ferroelectrics. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Gallium Nitride Direct Energy Conversion Betavoltaic Modeling and Optimization

    Science.gov (United States)

    2017-03-01

    power source. Autonomous systems such as space satellites require power sources that have strict size , weight, and power (SWaP) limitations, which...conversion process, called beta- photovoltaics , has a system efficiency that is dependent on both the conversion efficiency of the phosphor and the...effectively providing 9 J per day for autonomous systems . However, the volume for beta- photovoltaics is larger due to the need for phosphors to

  6. Limits to solar power conversion efficiency with applications to quantum and thermal systems

    Science.gov (United States)

    Byvik, C. E.; Buoncristiani, A. M.; Smith, B. T.

    1983-01-01

    An analytical framework is presented that permits examination of the limit to the efficiency of various solar power conversion devices. Thermodynamic limits to solar power efficiency are determined for both quantum and thermal systems, and the results are applied to a variety of devices currently considered for use in space systems. The power conversion efficiency for single-threshold energy quantum systems receiving unconcentrated air mass zero solar radiation is limited to 31 percent. This limit applies to photovoltaic cells directly converting solar radiation, or indirectly, as in the case of a thermophotovoltaic system. Photoelectrochemical cells rely on an additional chemical reaction at the semiconductor-electrolyte interface, which introduces additional second-law demands and a reduction of the solar conversion efficiency. Photochemical systems exhibit even lower possible efficiencies because of their relatively narrow absorption bands. Solar-powered thermal engines in contact with an ambient reservoir at 300 K and operating at maximum power have a peak conversion efficiency of 64 percent, and this occurs for a thermal reservoir at a temperature of 2900 K. The power conversion efficiency of a solar-powered liquid metal magnetohydrodydnamic generator, a solar-powered steam turbine electric generator, and an alkali metal thermoelectric converter is discussed.

  7. Solid State Energy Conversion Alliance 2nd Annual Workshop Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    National Energy Technology Laboratory

    2001-03-30

    The National Energy Technology Laboratory (NETL) and the Pacific Northwest National Laboratory (PNNL) are pleased to provide the proceedings of the second annual Solid State Energy Conversion Alliance (SECA) Workshop held on March 29-30, 2001 in Arlington. The package includes the presentations made during the workshop, a list of participants, and the results of the breakout sessions. Those sessions covered stack materials and processes, power electronics, balance of plant and thermal integration, fuel processing technologies, and stack and system performance modeling. The breakout sessions have been reported as accurately as possible; however, due to the recording and transcription process errors may have occurred. If you note any significant omissions or wish to provide additional information, we welcome your comments and hope that all stakeholder groups will use the enclosed information in their planning endeavors.

  8. Solid State Energy Conversion Alliance 2nd Annual Workshop Proceedings

    International Nuclear Information System (INIS)

    National Energy Technology Laboratory

    2001-01-01

    The National Energy Technology Laboratory (NETL) and the Pacific Northwest National Laboratory (PNNL) are pleased to provide the proceedings of the second annual Solid State Energy Conversion Alliance (SECA) Workshop held on March 29-30, 2001 in Arlington. The package includes the presentations made during the workshop, a list of participants, and the results of the breakout sessions. Those sessions covered stack materials and processes, power electronics, balance of plant and thermal integration, fuel processing technologies, and stack and system performance modeling. The breakout sessions have been reported as accurately as possible; however, due to the recording and transcription process errors may have occurred. If you note any significant omissions or wish to provide additional information, we welcome your comments and hope that all stakeholder groups will use the enclosed information in their planning endeavors

  9. GT-MHR power conversion system: Design status and technical issues

    International Nuclear Information System (INIS)

    Etzel, K.; Baccaglini, G.; Schwartz, A.; Hillman, S.; Mathis, D.

    1994-12-01

    The Modular Helium Reactor (MHR) builds on 30 years of international gas-cooled reactor experience utilizing the unique properties of helium gas coolant, graphite moderator and coated particle fuel. To efficiently utilize the high temperature potential of the MHR, an innovative power conversion system has been developed featuring an intercooled and recuperated gas turbine. The gas turbine replaces a conventional steam turbine and its many auxiliary components. The Power Conversion System converts the thermal energy of the helium directly into electrical energy utilizing a closed Brayton cycle. The Power Conversion System draws on even more years of experience than the MHR: the world's first closed-cycle plant, fossil fired and utilizing air as working fluid, started operation in Switzerland in 1939. Shortly thereafter, in 1945, the coupling of a closed-cycle plant to a nuclear heat generation system was conceived. Directly coupling the closed-cycle gas turbine concept to a modern, passively safe nuclear reactor opens a new chapter in power generation technology and brings with it various design challenges. Some of these challenges are associated with the direct coupling of the Power Conversion System to a nuclear reactor. Since the primary coolant is also the working fluid, the Power Conversion System has to be designed for reactor radionuclide plateout. As a result, issues like component maintainability and replaceability, and fission product effects on materials must be addressed. Other issues concern the integration of the Power Conversion System components into a single vessel. These issues include the selection of key technologies for the power conversion components such as submerged generator, magnetic bearings, seals, compact heat exchangers, and the overall system layout

  10. TinyPowerPower conversion on a tiny scale

    DEFF Research Database (Denmark)

    Han, Anpan; Jørgensen, Anders Michael

    2014-01-01

    The world surrounding us is filled with devices relying on electrical power and the rise of internet-of-thingswill mean that powering devices will remain important in the future. The size and cost of the power supplyhas become a dominant factor in many applications. At the same time, most of the ...... project is an ambitious approach to taking miniature power converters into a new domainand the trickle-down effect on micro fabricated inductors can hopefully benefit other projects....

  11. The state of the art of wind energy conversion systems and technologies: A review

    International Nuclear Information System (INIS)

    Cheng, Ming; Zhu, Ying

    2014-01-01

    Highlights: • This paper reviews the state of the art of wind energy conversion systems. • Different types of common wind energy conversion systems are classified and compared. • The four most popular MPPT control methods are reviewed and compared. • The latest development of wind energy conversion technologies is introduced. • Future trends of the wind energy conversion technologies are discussed. - Abstract: This paper gives a comprehensive review of the state of the art of wind energy conversion systems (WECS) and technologies, with an emphasis on wind power generator and control. First, different types of common WECSs are classified according to their features and drive train types. The WECSs are compared on the basis of the volume, weight, cost, efficiency, system reliability and fault ride through capability. The maximum power point tracking (MPPT) control, which aims to make the generator speed meet an optimum value to ensure the maximum energy yield, plays a key role in the variable speed WECSs. A comprehensive review and comparison of the four most popular MPPT control methods are carried out and improvements for each method are presented. Furthermore, the latest development of wind energy conversion technologies is introduced, such as the brushless doubly fed induction generator (BDFIG), the stator permanent magnet synchronous generators, the magnetic-geared generators, dual power flow WECS with the electrical variable transmission (EVT) machine, and direct grid-connected WECS. Finally, the future trends of the technologies are discussed

  12. Design and Performance of Energy Conversion Units of Betavoltaic Isotopic Batteries

    International Nuclear Information System (INIS)

    Wang Guanquan; Yang Yuqing; Zhang Huaming; Hu Rui; Wei Hongyuan; Xiong Xiaoling; Luo Shunzhong

    2010-01-01

    Based on the single crystal silicon semiconductor junction devices, the relationships between their configurable parameters and the electrical properties were discussed for the purpose of design of energy conversion units of betavoltaic isotopic batteries. Two kinds of silicon semiconductor junction devices as energy conversion units of betavoltaic batteries were designed and customized. The electrical output properties of the devices irradiated by 63 Ni source were measured. The results show that the new designed devices perform better than the existing commercial one in open-circuit voltage, output power and energy conversion efficiency. (authors)

  13. 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....

  14. Energy sources and power plants

    International Nuclear Information System (INIS)

    Schulz, Detlef; Schulz, Karen

    2013-01-01

    Energy is obtained from various energy sources (coal, petroleum, natural gas, nuclear fuels, wind energy, solar energy, hydro power, biomass, geothermal energy). These differ in each case with respect to their availability, methods of their production and the required power plant technologies. As technologies of the future fuel cells and nuclear fusion are traded. [de

  15. Physical aspects of ferroelectric semiconductors for photovoltaic solar energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Varo, Pilar [Departamento de Electrónica y Tecnología de Computadores, CITIC-UGR, Universidad de Granada, 18071 Granada (Spain); Bertoluzzi, Luca [Institute of Advanced Materials (INAM), Universitat Jaume I, 12006 Castelló (Spain); Bisquert, Juan, E-mail: bisquert@uji.es [Institute of Advanced Materials (INAM), Universitat Jaume I, 12006 Castelló (Spain); Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia); Alexe, Marin [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Coll, Mariona [Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193, Bellaterra, Catalonia (Spain); Huang, Jinsong [Department of Mechanical and Materials Engineering and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE 68588-0656 (United States); Jimenez-Tejada, Juan Antonio [Departamento de Electrónica y Tecnología de Computadores, CITIC-UGR, Universidad de Granada, 18071 Granada (Spain); Kirchartz, Thomas [IEK5-Photovoltaik, Forschungszentrum Jülich, 52425 Jülich (Germany); Faculty of Engineering and CENIDE, University of Duisburg–Essen, Carl-Benz-Str. 199, 47057 Duisburg (Germany); Nechache, Riad; Rosei, Federico [INRS—Center Énergie, Matériaux et Télécommunications, Boulevard Lionel-Boulet, Varennes, Québec, J3X 1S2 (Canada); Yuan, Yongbo [Department of Mechanical and Materials Engineering and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE 68588-0656 (United States)

    2016-10-07

    Solar energy conversion using semiconductors to fabricate photovoltaic devices relies on efficient light absorption, charge separation of electron–hole pair carriers or excitons, and fast transport and charge extraction to counter recombination processes. Ferroelectric materials are able to host a permanent electrical polarization which provides control over electrical field distribution in bulk and interfacial regions. In this review, we provide a critical overview of the physical principles and mechanisms of solar energy conversion using ferroelectric semiconductors and contact layers, as well as the main achievements reported so far. In a ferroelectric semiconductor film with ideal contacts, the polarization charge would be totally screened by the metal layers and no charge collection field would exist. However, real materials show a depolarization field, smooth termination of polarization, and interfacial energy barriers that do provide the control of interface and bulk electric field by switchable spontaneous polarization. We explore different phenomena as the polarization-modulated Schottky-like barriers at metal/ferroelectric interfaces, depolarization fields, vacancy migration, and the switchable rectifying behavior of ferroelectric thin films. Using a basic physical model of a solar cell, our analysis provides a general picture of the influence of ferroelectric effects on the actual power conversion efficiency of the solar cell device, and we are able to assess whether these effects or their combinations are beneficial or counterproductive. We describe in detail the bulk photovoltaic effect and the contact layers that modify the built-in field and the charge injection and separation in bulk heterojunction organic cells as well as in photocatalytic and water splitting devices. We also review the dominant families of ferroelectric materials that have been most extensively investigated and have provided the best photovoltaic performance.

  16. Physical aspects of ferroelectric semiconductors for photovoltaic solar energy conversion

    International Nuclear Information System (INIS)

    Lopez-Varo, Pilar; Bertoluzzi, Luca; Bisquert, Juan; Alexe, Marin; Coll, Mariona; Huang, Jinsong; Jimenez-Tejada, Juan Antonio; Kirchartz, Thomas; Nechache, Riad; Rosei, Federico; Yuan, Yongbo

    2016-01-01

    Solar energy conversion using semiconductors to fabricate photovoltaic devices relies on efficient light absorption, charge separation of electron–hole pair carriers or excitons, and fast transport and charge extraction to counter recombination processes. Ferroelectric materials are able to host a permanent electrical polarization which provides control over electrical field distribution in bulk and interfacial regions. In this review, we provide a critical overview of the physical principles and mechanisms of solar energy conversion using ferroelectric semiconductors and contact layers, as well as the main achievements reported so far. In a ferroelectric semiconductor film with ideal contacts, the polarization charge would be totally screened by the metal layers and no charge collection field would exist. However, real materials show a depolarization field, smooth termination of polarization, and interfacial energy barriers that do provide the control of interface and bulk electric field by switchable spontaneous polarization. We explore different phenomena as the polarization-modulated Schottky-like barriers at metal/ferroelectric interfaces, depolarization fields, vacancy migration, and the switchable rectifying behavior of ferroelectric thin films. Using a basic physical model of a solar cell, our analysis provides a general picture of the influence of ferroelectric effects on the actual power conversion efficiency of the solar cell device, and we are able to assess whether these effects or their combinations are beneficial or counterproductive. We describe in detail the bulk photovoltaic effect and the contact layers that modify the built-in field and the charge injection and separation in bulk heterojunction organic cells as well as in photocatalytic and water splitting devices. We also review the dominant families of ferroelectric materials that have been most extensively investigated and have provided the best photovoltaic performance.

  17. Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 3: Energy conversion subsystems and components. Part 1: Bottoming cycles and materials of construction

    Science.gov (United States)

    Shah, R. P.; Solomon, H. D.

    1976-01-01

    Energy conversion subsystems and components were evaluated in terms of advanced energy conversion systems. Results of the bottoming cycles and materials of construction studies are presented and discussed.

  18. Fine-Tuning the Energy Levels of a Nonfullerene Small-Molecule Acceptor to Achieve a High Short-Circuit Current and a Power Conversion Efficiency over 12% in Organic Solar Cells.

    Science.gov (United States)

    Kan, Bin; Zhang, Jiangbin; Liu, Feng; Wan, Xiangjian; Li, Chenxi; Ke, Xin; Wang, Yunchuang; Feng, Huanran; Zhang, Yamin; Long, Guankui; Friend, Richard H; Bakulin, Artem A; Chen, Yongsheng

    2018-01-01

    Organic solar cell optimization requires careful balancing of current-voltage output of the materials system. Here, such optimization using ultrafast spectroscopy as a tool to optimize the material bandgap without altering ultrafast photophysics is reported. A new acceptor-donor-acceptor (A-D-A)-type small-molecule acceptor NCBDT is designed by modification of the D and A units of NFBDT. Compared to NFBDT, NCBDT exhibits upshifted highest occupied molecular orbital (HOMO) energy level mainly due to the additional octyl on the D unit and downshifted lowest unoccupied molecular orbital (LUMO) energy level due to the fluorination of A units. NCBDT has a low optical bandgap of 1.45 eV which extends the absorption range toward near-IR region, down to ≈860 nm. However, the 60 meV lowered LUMO level of NCBDT hardly changes the V oc level, and the elevation of the NCBDT HOMO does not have a substantial influence on the photophysics of the materials. Thus, for both NCBDT- and NFBDT-based systems, an unusually slow (≈400 ps) but ultimately efficient charge generation mediated by interfacial charge-pair states is observed, followed by effective charge extraction. As a result, the PBDB-T:NCBDT devices demonstrate an impressive power conversion efficiency over 12%-among the best for solution-processed organic solar cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Impedance-Source Networks for Electric Power Conversion Part I

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Peng, Fang Zheng; Blaabjerg, Frede

    2015-01-01

    power chain, which may improve the reliability and performance of the power system. The first part of this paper provides a comprehensive review of the various impedance-source-networks-based power converters and discusses the main topologies from an application point of view. This review paper...... is the first of its kind with the aim of providing a “one-stop” information source and a selection guide on impedance-source networks for power conversion for researchers, designers, and application engineers. A comprehensive review of various modeling, control, and modulation techniques for the impedance...

  20. Experimental model of a wind energy conversion system

    Science.gov (United States)

    Vasar, C.; Rat, C. L.; Prostean, O.

    2018-01-01

    The renewable energy domain represents an important issue for the sustainable development of the mankind in the actual context of increasing demand for energy along with the increasing pollution that affect the environment. A significant quota of the clean energy is represented by the wind energy. As a consequence, the developing of wind energy conversion systems (WECS) in order to achieve high energetic performances (efficiency, stability, availability, competitive cost etc) represents a topic of permanent actuality. Testing and developing of an optimized control strategy for a WECS direct implemented on a real energetic site is quite difficult and not cost efficient. Thus a more convenient solution consists in a flexible laboratory setup which requires an experimental model of a WECS. Such approach would allow the simulation of various real conditions very similar with existing energetic sites. This paper presents a grid-connected wind turbine emulator. The wind turbine is implemented through a real-time Hardware-in-the-Loop (HIL) emulator, which will be analyzed extensively in the paper. The HIL system uses software implemented in the LabVIEW programming environment to control an ABB ACS800 electric drive. ACS800 has the task of driving an induction machine coupled to a permanent magnet synchronous generator. The power obtained from the synchronous generator is rectified, filtered and sent to the main grid through a controlled inverter. The control strategy is implemented on a NI CompactRIO (cRIO) platform.

  1. RF Power Transfer, Energy Harvesting, and Power Management Strategies

    Science.gov (United States)

    Abouzied, Mohamed Ali Mohamed

    Energy harvesting is the way to capture green energy. This can be thought of as a recycling process where energy is converted from one form (here, non-electrical) to another (here, electrical). This is done on the large energy scale as well as low energy scale. The former can enable sustainable operation of facilities, while the latter can have a significant impact on the problems of energy constrained portable applications. Different energy sources can be complementary to one another and combining multiple-source is of great importance. In particular, RF energy harvesting is a natural choice for the portable applications. There are many advantages, such as cordless operation and light-weight. Moreover, the needed infra-structure can possibly be incorporated with wearable and portable devices. RF energy harvesting is an enabling key player for Internet of Things technology. The RF energy harvesting systems consist of external antennas, LC matching networks, RF rectifiers for ac to dc conversion, and sometimes power management. Moreover, combining different energy harvesting sources is essential for robustness and sustainability. Wireless power transfer has recently been applied for battery charging of portable devices. This charging process impacts the daily experience of every human who uses electronic applications. Instead of having many types of cumbersome cords and many different standards while the users are responsible to connect periodically to ac outlets, the new approach is to have the transmitters ready in the near region and can transfer power wirelessly to the devices whenever needed. Wireless power transfer consists of a dc to ac conversion transmitter, coupled inductors between transmitter and receiver, and an ac to dc conversion receiver. Alternative far field operation is still tested for health issues. So, the focus in this study is on near field. The goals of this study are to investigate the possibilities of RF energy harvesting from various

  2. Organic electronics on fibers for energy conversion applications

    Science.gov (United States)

    O'Connor, Brendan T.

    Currently, there is great demand for pollution-free and renewable sources of electricity. Solar cells are particularly attractive from the standpoint of sunlight abundance. However, truly widespread adoption of solar cells is impeded by the high cost and poor scalability of existing technologies. For example, while 53,000 mi2 of 10% efficient solar cell modules would be required to supply the current U.S. energy demand, only about 50 mi2 have been installed worldwide. Organic semiconductors potentially offer a route to realizing low-cost solar cell modules, but currently suffer from low conversion efficiency. For organic-based solar cells to become commercially viable, further research is required to improve device performance, develop scalable manufacturing methods, and reduce installation costs via, for example, novel device form factors. This thesis makes several contributions to the field of organic solar cells, including the replacement of costly and brittle indium tin oxide (ITO) electrodes by inexpensive and malleable, thin metal films, and the application of external dielectric coatings to improve power conversion efficiency. Furthermore, we show that devices with non-planar geometries (e.g. organic solar cells deposited onto long fibers) can have higher efficiencies than conventional planar devices. Building on these results, we demonstrate novel fiber-based organic light emitting devices (OLEDs) that offer substantially improved color quality and manufacturability as a next-generation solid-state lighting technology. An intriguing possibility afforded by the fiber-based device architectures is the ability to integrate energy conversion and lighting functionalities with textiles, a mature, commodity-scale technology.

  3. Limitations of power conversion systems under transient loads and impact on the pulsed tokamak power reactor

    International Nuclear Information System (INIS)

    Sager, G.T.; Wong, C.P.C.; Kapich, D.D.; McDonald, C.F.; Schleicher, R.W.

    1993-11-01

    The impact of cyclic loading of the power conversion system of a helium-cooled, pulsed tokamak power plant is assessed. Design limits of key components of heat transport systems employing Rankie and Brayton thermodynamic cycles are quantified based on experience in gas-cooled fission reactor design and operation. Cyclic loads due to pulsed tokamak operation are estimated. Expected performance of the steam generator is shown to be incompatible with pulsed tokamak operation without load leveling thermal energy storage. The close cycle gas turbine is evaluated qualitatively based on performance of existing industrial and aeroderivative gas turbines. Advances in key technologies which significantly improve prospects for operation with tokamak fusion plants are reviewed

  4. Direct energy conversion - state of the art in 1981

    International Nuclear Information System (INIS)

    Euler, K.J.

    1981-01-01

    Contemporary research and development of direct energy conversion (D.E.C.) started about 25 years ago. Having considered possibilities, cost, and advantages, the efforts have become more and more steady during the last decade. It has been recognized that, in most cases, D.E.C. methods will serve only as electricity sources for special application. This is true for radioisotopic generators used in space and submarine technologies, for thermoelectric devices used in air defence and along desert pipelines, and for thermionic convertors used in television satellites. Thus, the goal, to introduce these D.E.C. units in large scale manufacture has not been reached, and will not be reached even in the future. Only magneto-hydrodynamic channels exhibit a certain innovation potential as topping devices in advanced thermal power stations. Fuel cells will not be treated here, solar cells only mentioned briefly. (orig.) [de

  5. Integrated bioenergy conversion concepts for small scale gasification power systems

    Science.gov (United States)

    Aldas, Rizaldo Elauria

    microorganisms used to deal with tars are selected and pre-conditioned to the tar environment. Overall, the results provided a basis for operational and design strategy for a combined gasification system but further study is recommended such as determination of the impacts in terms of emissions, power, efficiency and costs associated with the use of producer gas-enriched biogas taking advantage of hydrogen enrichment to reduce NOx and other pollutants in reciprocating engines and other energy conversion systems.

  6. Impedance-Source Networks for Electric Power Conversion Part II

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Peng, Fang Zheng; Blaabjerg, Frede

    2015-01-01

    Impedance-source networks cover the entire spectrum of electric power conversion applications (dc-dc, dc-ac, ac-dc, ac-ac) controlled and modulated by different modulation strategies to generate the desired dc or ac voltage and current at the output. A comprehensive review of various impedance......-source-network-based power converters has been covered in a previous paper and main topologies were discussed from an application point of view. Now Part II provides a comprehensive review of the most popular control and modulation strategies for impedance-source network-based power converters/inverters. These methods...

  7. Power conversion unit for the South African direct cycle HTGR

    International Nuclear Information System (INIS)

    Liebenberg, J.J.

    1997-01-01

    The system parameters chosen to optimise the thermal efficiency of the Eskom PBMR whilst maintaining component simplicity is discussed. Power Conversion Unit components, which are now at a preliminary design stage comprise a precooler, two turbo units consisting of a turbine driven compressor, recuperator and a power turbine, driving an alternator. Design aspects of every component is mentioned and the inventory method of poorer control is explained with reference to start-up and and shut-down events, the system an effective load following device, down to 4% of full power. Application of the same design principles for HTGRs smaller than 25 MWe is discussed. (author)

  8. Supporting Current Energy Conversion Projects through Numerical Modeling

    Science.gov (United States)

    James, S. C.; Roberts, J.

    2016-02-01

    The primary goals of current energy conversion (CEC) technology being developed today are to optimize energy output and minimize environmental impact. CEC turbines generate energy from tidal and current systems and create wakes that interact with turbines located downstream of a device. The placement of devices can greatly influence power generation and structural reliability. CECs can also alter the environment surrounding the turbines, such as flow regimes, sediment dynamics, and water quality. These alterations pose potential stressors to numerous environmental receptors. Software is needed to investigate specific CEC sites to simulate power generation and hydrodynamic responses of a flow through a CEC turbine array so that these potential impacts can be evaluated. Moreover, this software can be used to optimize array layouts that yield the least changes to the environmental (i.e., hydrodynamics, sediment dynamics, and water quality). Through model calibration exercises, simulated wake profiles and turbulence intensities compare favorably to the experimental data and demonstrate the utility and accuracy of a fast-running tool for future siting and analysis of CEC arrays in complex domains. The Delft3D modeling tool facilitates siting of CEC projects through optimization of array layouts and evaluation of potential environmental effect all while provide a common "language" for academics, industry, and regulators to be able to discuss the implications of marine renewable energy projects. Given the enormity of any full-scale marine renewable energy project, it necessarily falls to modeling to evaluate how array operations must be addressed in an environmental impact statement in a way that engenders confidence in the assessment of the CEC array to minimize environmental effects.

  9. Recent Progress on Integrated Energy Conversion and Storage Systems.

    Science.gov (United States)

    Luo, Bin; Ye, Delai; Wang, Lianzhou

    2017-09-01

    Over the last few decades, there has been increasing interest in the design and construction of integrated energy conversion and storage systems (IECSSs) that can simultaneously capture and store various forms of energies from nature. A large number of IECSSs have been developed with different combination of energy conversion technologies such as solar cells, mechanical generators and thermoelectric generators and energy storage devices such as rechargeable batteries and supercapacitors. This review summarizes the recent advancements to date of IECSSs based on different energy sources including solar, mechanical, thermal as well as multiple types of energies, with a special focus on the system configuration and working mechanism. With the rapid development of new energy conversion and storage technologies, innovative high performance IECSSs are of high expectation to be realised for diverse practical applications in the near future.

  10. Calculating the share of process energy consumed by biomass conversion plants. Bestimmung der Anteile der Prozessenergie bei einer Biogasanlage

    Energy Technology Data Exchange (ETDEWEB)

    Goebel, W

    1984-06-01

    During the winter season the process energy consumption of biomass conversion plants is relatively high. Apart from the quantity and temperature of manures and insulation of the fermentation tank the process energy consumption depends on the efficiency of the heating system. Moreover, heat losses decide on the required quantities of process energy. Compared with the process energy consumption the electric power consumption of the engines supplying the biomass conversion plant is relatively low. Along with calculations tests and measurements in a biomass conversion plant during the winter season of 1981/1982 give access to the interrelation between process energy and electric power consumption.

  11. Energy conversion device with support member having pore channels

    Science.gov (United States)

    Routkevitch, Dmitri [Longmont, CO; Wind, Rikard A [Johnstown, CO

    2014-01-07

    Energy devices such as energy conversion devices and energy storage devices and methods for the manufacture of such devices. The devices include a support member having an array of pore channels having a small average pore channel diameter and having a pore channel length. Material layers that may include energy conversion materials and conductive materials are coaxially disposed within the pore channels to form material rods having a relatively small cross-section and a relatively long length. By varying the structure of the materials in the pore channels, various energy devices can be fabricated, such as photovoltaic (PV) devices, radiation detectors, capacitors, batteries and the like.

  12. Microfluidic energy conversion by application of two phase flow

    NARCIS (Netherlands)

    Xie, Yanbo

    2013-01-01

    We investigated the energy conversion performance by the streaming potential using totally different approaches. By introducing gas bubbles, which can be considered as perfect insulators, the internal electrical resistance of the system can be increased, decreasing the conduction current. Following

  13. Advanced Reactor Technology/Energy Conversion Project FY17 Accomplishments.

    Energy Technology Data Exchange (ETDEWEB)

    Rochau, Gary E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-02-01

    The purpose of the ART Energy Conversion (EC) Project is to provide solutions to convert the heat from an advanced reactor to useful products that support commercial application of the reactor designs.

  14. Energy conversion phenomena in plug-in hybrid-electric vehicles

    International Nuclear Information System (INIS)

    Katrasnik, Tomaz

    2011-01-01

    Research highlights: → Energy conversion phenomena of PHEVs for different drive cycles and depletion rates of energy sources. → Detailed physically based framework for analyzing energy conversion phenomena in PHEVs. → Interaction of energy flows and energy losses with energy consumption of the PHEV. → Identification and explanation of mechanisms leading to optimal tank-to-wheel efficiency. → Analysis of well-to-wheel efficiencies for different realistic well-to-tank scenarios. -- Abstract: Energy flows and energy conversion efficiencies of commercial plug-in hybrid-electric vehicles (PHEV) are analyzed for parallel and series PHEV topologies. The analysis is performed by a combined analytical and simulation approach. Combined approach enables evaluation of energy losses on different energy paths and provides their impact on the energy consumption of the PHEV. Thereby the paper reveals energy conversion phenomena of different PHEV topologies operating according to charge depleting and charge sustaining modes as well as according to different test cycles. It is shown in the paper that amount of the energy depleted from both on-board energy sources is significantly influenced by the efficiencies of energy conversion chains from on-board energy sources to the wheels. It is also shown that energy used to power the PHEV according to particular test cycles varies based on its operating mode, which influences energy flows on different energy paths within the PHEVs and consequently overall energy consumed by the PHEV. The paper additionally discusses well-to-wheel efficiencies considering different realistic well-to-tank scenarios. It is shown that well-to-tank efficiency of electric energy generation significantly influences optimal operating mode of the PHEV if consumption of primary energy sources is considered.

  15. Socio-economic overview of wind energy conversion systems

    International Nuclear Information System (INIS)

    Hardy, D.R.

    1992-01-01

    A social scientist's perspective is presented on the socio-economic impacts of wind energy conversion systems (WECS) in Ontario. The main organization for delivering electricity in Ontario is Ontario Hydro. This utility has two WECS, an experimental 3.5 kW generator and a hybrid wind/diesel facility at a remote northern community. Ontario Hydro is reviewing its supply options and anticipates wind power would likely be used in niche applications involving off-grid hybrid systems where the cost of displaced generation is high. On-grid applications would likely be in the form of dispersed non-utility generation. The potential contribution of wind power to Ontario's electricity supply mix could be as little as 1 MW by the year 2000 or as high as 40 MW by the year 2014, depending on costs and technological developments. Socio-economic criteria used by the utility for assessing individual supply options include job creation, regional economic development, local community impacts, social acceptance, and distribution of risks and benefits. Initial observations of potential effects of WECS are discussed, including site selection, manufacturing, construction, and operation. Barriers to implementation of WECS in Ontario include the limited number of good wind sites, the intermittent nature of WECS power, and the currently uneconomic nature of WECS for bulk electricity systems. However, WECS have environmentally attractive features and are socially acceptable. 10 refs., 3 figs

  16. Ocean Thermal Energy Conversion Using Double-Stage Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Yasuyuki Ikegami

    2018-03-01

    Full Text Available Ocean Thermal Energy Conversion (OTEC using non-azeotropic mixtures such as ammonia/water as working fluid and the multistage cycle has been investigated in order to improve the thermal efficiency of the cycle because of small ocean temperature differences. The performance and effectiveness of the multistage cycle are barely understood. In addition, previous evaluation methods of heat exchange process cannot clearly indicate the influence of the thermophysical characteristics of the working fluid on the power output. Consequently, this study investigated the influence of reduction of the irreversible losses in the heat exchange process on the system performance in double-stage Rankine cycle using pure working fluid. Single Rankine, double-stage Rankine and Kalina cycles were analyzed to ascertain the system characteristics. The simple evaluation method of the temperature difference between the working fluid and the seawater is applied to this analysis. From the results of the parametric performance analysis it can be considered that double-stage Rankine cycle using pure working fluid can reduce the irreversible losses in the heat exchange process as with the Kalina cycle using an ammonia/water mixture. Considering the maximum power efficiency obtained in the study, double-stage Rankine and Kalina cycles can improve the power output by reducing the irreversible losses in the cycle.

  17. Direct Energy Conversion for Nuclear Propulsion at Low Specific Mass

    Science.gov (United States)

    Scott, John H.

    2014-01-01

    The project will continue the FY13 JSC IR&D (October-2012 to September-2013) effort in Travelling Wave Direct Energy Conversion (TWDEC) in order to demonstrate its potential as the core of a high potential, game-changing, in-space propulsion technology. The TWDEC concept converts particle beam energy into radio frequency (RF) alternating current electrical power, such as can be used to heat the propellant in a plasma thruster. In a more advanced concept (explored in the Phase 1 NIAC project), the TWDEC could also be utilized to condition the particle beam such that it may transfer directed kinetic energy to a target propellant plasma for the purpose of increasing thrust and optimizing the specific impulse. The overall scope of the FY13 first-year effort was to build on both the 2012 Phase 1 NIAC research and the analysis and test results produced by Japanese researchers over the past twenty years to assess the potential for spacecraft propulsion applications. The primary objective of the FY13 effort was to create particle-in-cell computer simulations of a TWDEC. Other objectives included construction of a breadboard TWDEC test article, preliminary test calibration of the simulations, and construction of first order power system models to feed into mission architecture analyses with COPERNICUS tools. Due to funding cuts resulting from the FY13 sequestration, only the computer simulations and assembly of the breadboard test article were completed. The simulations, however, are of unprecedented flexibility and precision and were presented at the 2013 AIAA Joint Propulsion Conference. Also, the assembled test article will provide an ion current density two orders of magnitude above that available in previous Japanese experiments, thus enabling the first direct measurements of power generation from a TWDEC for FY14. The proposed FY14 effort will use the test article for experimental validation of the computer simulations and thus complete to a greater fidelity the

  18. Potassium Rankine cycle power conversion systems for lunar-Mars surface power

    International Nuclear Information System (INIS)

    Holcomb, R.S.

    1992-01-01

    The potassium Rankine cycle has good potential for application to nuclear power systems for surface power on the moon and Mars. A substantial effort on the development of the power conversion system was carried out in the 1960's which demonstrated successful operation of components made of stainless steel at moderate temperatures. This technology could be applied in the near term to produce a 360 kW(e) power system by coupling a stainless steel power conversion system to the SP-100 reactor. Improved performance could be realized in later systems by utilizing niobium or tantalum refractory metal alloys in the reactor and power conversion system. The design characteristics and estimated mass of power systems for each of three technology levels are presented in the paper

  19. Achieving sustainable biomass conversion to energy and bio products

    International Nuclear Information System (INIS)

    Matteson, G. C.

    2009-01-01

    The present effort in to maximize biomass conversion-to-energy and bio products is examined in terms of sustain ability practices. New goals, standards in practice, measurements and certification are needed for the sustainable biomass industry. Sustainable practices produce biomass energy and products in a manner that is secure, renewable, accessible locally, and pollution free. To achieve sustainable conversion, some new goals are proposed. (Author)

  20. Reactor technology: power conversion systems and reactor operation and maintenance

    International Nuclear Information System (INIS)

    Powell, J.R.

    1977-01-01

    The use of advanced fuels permits the use of coolants (organic, high pressure helium) that result in power conversion systems with good thermal efficiency and relatively low cost. Water coolant would significantly reduce thermal efficiency, while lithium and salt coolants, which have been proposed for DT reactors, will have comparable power conversion efficiencies, but will probably be significantly more expensive. Helium cooled blankets with direct gas turbine power conversion cycles can also be used with DT reactors, but activation problems will be more severe, and the portion of blanket power in the metallic structure will probably not be available for the direct cycle, because of temperature limitations. A very important potential advantage of advanced fuel reactors over DT fusion reactors is the possibility of easier blanket maintenance and reduced down time for replacement. If unexpected leaks occur, in most cases the leaking circuit can be shut off and a redundant cooling curcuit will take over the thermal load. With the D-He 3 reactor, it appears practical to do this while the reactor is operating, as long as the leak is small enough not to shut down the reactor. Redundancy for Cat-D reactors has not been explored in detail, but appears feasible in principle. The idea of mobile units operating in the reactor chamber for service and maintenance of radioactive elements is explored

  1. Work Began on Contracts for Radioisotope Power Conversion Technology Research and Development

    Science.gov (United States)

    Wong, Wayne A.

    2005-01-01

    NASA has had a history of successful space flight missions that depended on radioisotope-fueled power systems. These Radioisotope Power Systems (RPSs) converted the heat generated from the decay of radioisotope material into useful electrical power. An RPS is most attractive in applications where photovoltaics are not optimal, such as deep-space applications where the solar flux is too low or extended applications on planets such as Mars where the day/night cycle, settling of dust, and life requirements limit the usefulness of photovoltaics. NASA s Radioisotope Power Conversion Technology (RPCT) Program is developing next-generation power-conversion technologies that will enable future missions that have requirements that cannot be met by the two RPS flight systems currently being developed by the Department of Energy for NASA: the Multi-Mission Radioisotope Thermoelectric Generator and the Stirling Radioisotope Generator (SRG).

  2. Proceedings of the 30. intersociety energy conversion engineering conference. Volume 2

    International Nuclear Information System (INIS)

    Goswami, D.Y.; Kannberg, L.D.; Somasundaram, S.

    1995-01-01

    This conference provides a forum to present and discuss the engineering aspects of energy conversion, advanced and unconventional energy systems and devices, energy conversion and utilization, environmental issues and policy implications on research, development, and implementation of technologies. The solution for a sustainable future will lie in a mix of all of the available energy resources (renewable and non-renewable) and diverse energy conversion technologies that will maintain quality of life in a sustainable manner. The 100 papers in Volume 2 are divided into the following topical sections: (1) Environmental impact--Impacts and technologies; (2) Energy systems--Electric/hybrid vehicle technology; Transportation system assessments; Simulation and modeling of systems; Cogeneration and other energy systems; Thermal energy storage applications; Fluids and heat transfer topics; Demand-side management in buildings; and Energy management; (3) Policy impacts on energy--Developing countries and Global; (4) Renewable energy sources--Solar and geothermal power; Solar thermal power; Photovoltaics; Biomass power; Solar thermal; and Renewable energy--status and future. All papers have been processed separately for inclusion on the data base

  3. Conversion of biomass into energy source

    International Nuclear Information System (INIS)

    Antonescu, S.; Garjoaba, M.; Antonescu, A.

    2005-01-01

    This study assists the identification of possible application and markets of the CHP-plants in the NAS states, and forms the first part of a detailed study on economical and ecological prospects of small scale and large heat pipe reformers in NAS. It is well known that the energy strategy of the European Union, foresees the increase of the participation of the renewable energy from the total of the energy resources of the European Union, up to 12% in 2010. This participation is of a great importance for the adequate reduction of green house effect gases. From the energy production point of view it is proven the fact that in 2010 the production of renewable energy will be: electricity - 675 tWh; heat - 80 Mtoe (930 TWh). From the above mentioned energy demand, the biomass will cover: electricity - 230 TWh-34,1%; heat - 75 Mtoe (93,8%)

  4. Energy Conversion and Storage Requirements for Hybrid Electric Aircraft

    Science.gov (United States)

    Misra, Ajay

    2016-01-01

    Among various options for reducing greenhouse gases in future large commercial aircraft, hybrid electric option holds significant promise. In the hybrid electric aircraft concept, gas turbine engine is used in combination with an energy storage system to drive the fan that propels the aircraft, with gas turbine engine being used for certain segments of the flight cycle and energy storage system being used for other segments. The paper will provide an overview of various energy conversion and storage options for hybrid electric aircraft. Such options may include fuel cells, batteries, super capacitors, multifunctional structures with energy storage capability, thermoelectric, thermionic or a combination of any of these options. The energy conversion and storage requirements for hybrid electric aircraft will be presented. The role of materials in energy conversion and storage systems for hybrid electric aircraft will be discussed.

  5. Materials science for solar energy conversion systems

    CERN Document Server

    Granqvist, CG

    1991-01-01

    Rapid advances in materials technology are creating many novel forms of coatings for energy efficient applications in solar energy. Insulating heat mirrors, selective absorbers, transparent insulation and fluorescent concentrators are already available commercially. Radiative cooling, electrochromic windows and polymeric light pipes hold promise for future development, while chemical and photochemical processes are being considered for energy storage. This book investigates new material advances as well as applications, costs, reliability and industrial production of existing materials. Each c

  6. Teaching on ocean-wave-energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Falnes, J. [Norges teknisk-naturvitskaplege univ., Inst. for fysikk, Trondheim (Norway)

    2001-07-01

    Ocean-wave energy utilisation has for 27 years been a university research subject, in which the author has been active from the first year. In this paper he presents some information related to his teaching on the subject during many of these years. This includes teaching on the pre-university level and, in particular, development of the wave-energy module for an educational CD-ROM on sustainable technology and renewable energy. Education of the general public is very important. On the other hand teaching of doctor students and other wave-energy researchers is also a subject of the paper. (au)

  7. Biomass energy conversion workshop for industrial executives

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    The rising costs of energy and the risks of uncertain energy supplies are increasingly familiar problems in industry. Bottom line profits and even the simple ability to operate can be affected by spiralling energy costs. An often overlooked alternative is the potential to turn industrial waste or residue into an energy source. On April 9 and 10, 1979, in Claremont, California, the Solar Energy Research Institute (SERI), the California Energy Commission (CEC), and the Western Solar Utilization Network (WSUN) held a workshop which provided industrial managers with current information on using residues and wastes as industrial energy sources. Successful industrial experiences were described by managers from the food processing and forest product industries, and direct combustion and low-Btu gasification equipment was described in detail. These speakers' presentations are contained in this document. Some major conclusions of the conference were: numerous current industrial applications of wastes and residues as fuels are economic and reliable; off-the-shelf technologies exist for converting biomass wastes and residues to energy; a variety of financial (tax credits) and institutional (PUC rate structures) incentives can help make these waste-to-energy projects more attractive to industry. However, many of these incentives are still being developed and their precise impact must be evaluated on a case-by-case basis.

  8. Improvement of energy conversion efficiency and power generation in direct borohydride-hydrogen peroxide fuel cell: The effect of Ni-M core-shell nanoparticles (M = Pt, Pd, Ru)/Multiwalled Carbon Nanotubes on the cell performance

    Science.gov (United States)

    Hosseini, M. G.; Mahmoodi, R.

    2017-12-01

    In this study, core@shell nanoparticles with Ni as a core material and Pt, Pd and Ru as shell materials are synthesized on multiwalled carbon nanotube (MWCNT) as catalyst support using the sequence reduction method. The influence of Ni@Pt, Ni@Pd and Ni@Ru core@shell nanoparticles on MWCNT toward borohydride oxidation in alkaline solution is investigated by various three-electrode electrochemical techniques. Also, the impact of these anodic electrocatalysts on the performance of direct borohydride-hydrogen peroxide fuel cell (DBHPFC) is evaluated. The structural and morphological properties of electrocatalysts are studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). The results of three electrode investigations show that Ni@Pd/MWCNT has excellent catalytic activity since borohydride oxidation current density on Ni@Pd/MWCNT (34773.27 A g-1) is 1.37 and 9.19 times higher than those of Ni@Pt/MWCNT (25347.27 A g-1) and Ni@Ru/MWCNT (3782.83 A g-1), respectively. Also, the energy conversion efficiency and power density of DBHPFC with Ni@Pd/MWCNT (246.82 mW cm-2) increase to 34.27% and 51.53% respect to Ni@Pt/MWCNT (162.24 mW cm-2) and Ni@Ru/MWCNT (119.62 mW cm-2), respectively. This study reveals that Ni@Pd/MWCNT has highest activity toward borohydride oxidation and stability in fuel cell.

  9. Electrical energy conversion and transport an interactive computer-based approach

    CERN Document Server

    Karady, George G

    2013-01-01

    Provides relevant material for engineering students and practicing engineers who want to learn the basics of electrical power transmission, generation, and usage This Second Edition of Electrical Energy Conversion and Transport is thoroughly updated to address the recent environmental effects of electric power generation and transmission, which have become more important in conjunction with the deregulation of the industry. The maintenance and development of the electrical energy generation and transport industry requires well-trained engineers who are able to use mode

  10. Design of Novel Metal Nanostructures for Broadband Solar Energy Conversion

    Directory of Open Access Journals (Sweden)

    Kristine A. Zhang

    2015-01-01

    Full Text Available Solar power holds great potential as an alternative energy source, but current photovoltaic cells have much room for improvement in cost and efficiency. Our objective was to develop metal nanostructures whose surface plasmon resonance (SPR spectra closely match the solar spectrum to enhance light absorption and scattering. We employed the finite-difference time-domain simulation method to evaluate the effect of varying key parameters. A novel nanostructure with SPR absorption matching a region of the solar spectrum (300 to 1500 nm that contains 90% of solar energy was successfully designed. This structure consists of a large gold-silica core-shell structure with smaller gold nanoparticles and nanorods on its surface. Such complex nanostructures are promising for broad and tunable absorption spectra. In addition, we investigated the SPR of silver nanoparticle arrays, which can achieve scattering close to the solar spectrum. We demonstrated an improvement in efficiency of over 30% with optimal nanoparticle radius and periods of 75 nm and 325 nm, respectively. In combination, our studies enable high-efficiency, tunable, and cost-effective enhancement of both light absorption and scattering, which has potential applications in solar energy conversion as well as biomedical imaging.

  11. Novel, Integrated Reactor / Power Conversion System (LMR-AMTEC)

    Energy Technology Data Exchange (ETDEWEB)

    Pablo Rubiolo, Principal Investigator

    2003-03-21

    The main features of this project were the development of a long life (up to 10 years) Liquid Metal Reactor (LMR) and a static conversion subsystem comprising an Alkali Metal Thermal-to-Electric (AMTEC) topping cycle and a ThermoElectric (TE) Bottom cycle. Various coupling options of the LMR with the energy conversion subsystem were explored and, base in the performances found in this analysis, an Indirect Coupling (IC) between the LMR and the AMTEC/TE converters with Alkali Metal Boilers (AMB) was chosen as the reference design. The performance model of the fully integrated sodium-and potassium-AMTEC/TE converters shows that a combined conversion efficiency in excess of 30% could be achieved by the plant. (B204)

  12. Photonic Crystal Emitters for Thermophotovoltaic Energy Conversion

    International Nuclear Information System (INIS)

    Stelmakh, Veronika; Chan, Walker R; Joannopoulos, John D; Celanovic, Ivan; Ghebrebrhan, Michael; Soljacic, Marin

    2015-01-01

    This paper reports the design, fabrication, and characterization of 2D photonic crystal (PhC) thermal emitters for a millimeter-scale hydrocarbon TPV microgenerator as a possible replacement for batteries in portable microelectronics, robotics, etc. In our TPV system, combustion heats a PhC emitter to incandescence and the resulting radiation is converted by a low-bandgap TPV cell. The PhC tailors the photonic density of states to produce spectrally confined thermal emission that matches the bandgap of the TPV cell, enabling high heat-to-electricity conversion efficiency. The work builds on a previously developed fabrication process to produce a square array of cylindrical cavities in a metal substrate. We will present ongoing incremental improvements in the optical and thermo-mechanical properties, the fabrication process, and the system integration, as recently combined with fabrication using novel materials, such as sputtered coatings, to enable a monolithic system. (paper)

  13. Modeling and Coordinated Control Strategy of Large Scale Grid-Connected Wind/Photovoltaic/Energy Storage Hybrid Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Lingguo Kong

    2015-01-01

    Full Text Available An AC-linked large scale wind/photovoltaic (PV/energy storage (ES hybrid energy conversion system for grid-connected application was proposed in this paper. Wind energy conversion system (WECS and PV generation system are the primary power sources of the hybrid system. The ES system, including battery and fuel cell (FC, is used as a backup and a power regulation unit to ensure continuous power supply and to take care of the intermittent nature of wind and photovoltaic resources. Static synchronous compensator (STATCOM is employed to support the AC-linked bus voltage and improve low voltage ride through (LVRT capability of the proposed system. An overall power coordinated control strategy is designed to manage real-power and reactive-power flows among the different energy sources, the storage unit, and the STATCOM system in the hybrid system. A simulation case study carried out on Western System Coordinating Council (WSCC 3-machine 9-bus test system for the large scale hybrid energy conversion system has been developed using the DIgSILENT/Power Factory software platform. The hybrid system performance under different scenarios has been verified by simulation studies using practical load demand profiles and real weather data.

  14. Teaching elementary thermodynamics and energy conversion: Opinions

    International Nuclear Information System (INIS)

    Gaggioli, Richard A.

    2010-01-01

    This presentation deals with innovation in teaching and understanding of thermodynamic principles. Key features of the approach being advocated are: (a) postulation of the existence of entropy, (b) explicitly associating energy transfers with other transports, (c) stating the 2nd Law in terms of Gibbs' available-energy, (d) systematic use of software such as EES. The paper outlines and elaborates upon an introductory course. Major headings in the course are: basic concepts: properties, additive properties and balances, primitive properties, energy, 1st Law. entropy, elementary academic applications of balances, available-energy, second law, exergy, thermostatic property relations, EES. Applications to processes, fluid flow, Heat transfer, thermochemical. Applications to devices, single-process, compound-process, systems (consisting of devices and processes functioning together).

  15. Emerging electrochemical energy conversion and storage technologies

    Science.gov (United States)

    Badwal, Sukhvinder P. S.; Giddey, Sarbjit S.; Munnings, Christopher; Bhatt, Anand I.; Hollenkamp, Anthony F.

    2014-01-01

    Electrochemical cells and systems play a key role in a wide range of industry sectors. These devices are critical enabling technologies for renewable energy; energy management, conservation, and storage; pollution control/monitoring; and greenhouse gas reduction. A large number of electrochemical energy technologies have been developed in the past. These systems continue to be optimized in terms of cost, life time, and performance, leading to their continued expansion into existing and emerging market sectors. The more established technologies such as deep-cycle batteries and sensors are being joined by emerging technologies such as fuel cells, large format lithium-ion batteries, electrochemical reactors; ion transport membranes and supercapacitors. This growing demand (multi billion dollars) for electrochemical energy systems along with the increasing maturity of a number of technologies is having a significant effect on the global research and development effort which is increasing in both in size and depth. A number of new technologies, which will have substantial impact on the environment and the way we produce and utilize energy, are under development. This paper presents an overview of several emerging electrochemical energy technologies along with a discussion some of the key technical challenges. PMID:25309898

  16. Energy conversion and planning: an overview

    International Nuclear Information System (INIS)

    Staszesky, F.M.

    1984-01-01

    The author proposes that an adequate, reliable, and economical supply of electricity should be a major preoccupation of the government, business, and the social leadership of this country. The importance of nuclear power to this proposition is the topic of this paper

  17. A Conversation on Zero Net Energy Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Eley, Charles; Gupta, Smita; Torcellini, Paul; Mchugh, Jon; Liu, Bing; Higgins, Cathy; Iplikci, Jessica; Rosenberg, Michael I.

    2017-06-30

    The submitted Roundtable discussion covers zero net energy (ZNE) buildings and their expansion into the market as a more widely adopted approach for various building types and sizes. However, the market is still small, and this discussion brings together distinguished researchers, designers, policy makers, and program administrations to represent the key factors making ZNE building more widespread and mainstream from a broad perspective, including governments, utilities, energy-efficiency research institutes, and building owners. This roundtable was conducted by the ASHRAE Journal with Bing Liu, P.E., Member ASHRAE, Charles Eley, FAIA, P.E., Member ASHRAE; Smita Gupta, Itron; Cathy Higgins, New Buildings Institute; Jessica Iplikci, Energy Trust of Oregon; Jon McHugh, P.E., Member ASHRAE; Michael Rosenberg, Member ASHRAE; and Paul Torcellini, Ph.D., P.E., NREL.

  18. Rotating flux compressor for energy conversion

    International Nuclear Information System (INIS)

    Chowdhuri, P.; Linton, T.W.; Phillips, J.A.

    1983-01-01

    The rotating flux compressor (RFC) converts rotational kinetic energy into an electrical output pulse which would have higher energy than the electrical energy initially stored in the compressor. An RFC has been designed in which wedge-shaped rotor blades pass through the air gaps between successive turns of a solenoid, the stator. Magnetic flux is generated by pulsing the stator solenoids when the inductance is a maximum, i.e., when the flux fills the stator-solenoid volume. Connecting the solenoid across a load conserves the flux which is compressed within the small volume surrounding the stator periphery when the rotor blades cut into the free space between the stator plates, creating a minimum-inductance condition. The unique features of this design are: (1) no electrical connections (brushes) to the rotor; (2) no conventional windings; and (3) no maintenance. The device has been tested up to 5000 rpm of rotor speed

  19. Energy analysis of biochemical conversion processes of biomass to bioethanol

    Energy Technology Data Exchange (ETDEWEB)

    Bakari, M.; Ngadi, M.; Bergthorson, T. [McGill Univ., Ste-Anne-de-Bellevue, PQ (Canada). Dept. of Bioresource Engineering

    2010-07-01

    Bioethanol is among the most promising of biofuels that can be produced from different biomass such as agricultural products, waste and byproducts. This paper reported on a study that examined the energy conversion of different groups of biomass to bioethanol, including lignocelluloses, starches and sugar. Biochemical conversion generally involves the breakdown of biomass to simple sugars using different pretreatment methods. The energy needed for the conversion steps was calculated in order to obtain mass and energy efficiencies for the conversions. Mass conversion ratios of corn, molasses and rice straw were calculated as 0.3396, 0.2300 and 0.2296 kg of bioethanol per kg of biomass, respectively. The energy efficiency of biochemical conversion of corn, molasses and rice straw was calculated as 28.57, 28.21 and 31.33 per cent, respectively. The results demonstrated that lignocelluloses can be efficiently converted with specific microorganisms such as Mucor indicus, Rhizopus oryzae using the Simultaneous Saccharification and Fermentation (SSF) methods.

  20. IECEC '91; Proceedings of the 26th Intersociety Energy Conversion Engineering Conference, Boston, MA, Aug. 4-9, 1991. Vol 6

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Papers are presented on aerospace power systems (burst and pulse power, simulation, solar dynamics, and space nuclear systems, etc.), conversion technologies, electrochemical conversion, and energy conservation. Consideration is also given to energy systems and alternative fuels, renewable resource systems, Stirling engines and applications, and innovative and advanced systems (e.g., superconducting power and magnetic devices at high temperature)

  1. Aerodynamic Aspects of Wind Energy Conversion

    DEFF Research Database (Denmark)

    Sørensen, Jens Nørkær

    2011-01-01

    This article reviews the most important aerodynamic research topics in the field of wind energy. Wind turbine aerodynamics concerns the modeling and prediction of aerodynamic forces, such as performance predictions of wind farms, and the design of specific parts of wind turbines, such as rotor...

  2. Innovative Breakwaters Design for Wave Energy Conversion

    DEFF Research Database (Denmark)

    Vicinanza, Diego; Stagonas, D.; Müller, G.

    2012-01-01

    the rubble mound breakwaters and seawalls related activity and the energy demand of small human communities. Wave loadings and overtopping on a seawall and rubble mound breakwater with front reservoir are discussed on the basis of physical 2-D model tests carried out at University of Southampton (UK...

  3. Experimental facility for explosive energy conversion into coherent microwave radiation

    International Nuclear Information System (INIS)

    Vdovin, V.A.; Korzhenevskij, A.V.; Cherepenin, V.A.

    2003-01-01

    The explosive energy conversion into the microwave radiation energy is considered with application of the explosion magnetic generator, heavy-current electron accelerator and Cherenkov microwave range generator. The electron accelerator formed the beam of 33 cm in diameter and current of ∼ 25 kA. The electrodynamic system of the SHF-generator has the diameter of ∼ 35 cm and it is accomplished in the form of the periodical nonuniform dielectric. The proposed explosive energy conversion scheme makes it possible to obtain the radiation capacity of approximately 100 MW in the 3-cm wave range by the pulse duration of ∼ 800 ns [ru

  4. Intelligent control with implementation on the wind energy conversion system

    International Nuclear Information System (INIS)

    Basma, Mohamad Khalil

    1997-05-01

    In this thesis our main job is to compare intelligent control and conventional control algorithms, by applying each scheme to the same control problem. Based on simulation, we analyze and compare the results of applying fuzzy logic and neural networks controllers on a popular control problem: variable speed wind energy conversion system. The reason behind our choice is the challenging nature of the problem where the plant should be controlled to maximize the power generated, while respecting its hardware constraints under varying operating conditions and disturbances. We have shown the effectiveness of fuzzy logic exciter controller for the adopted wind energy generator when compared to a conventional PI exciter. It showed better performance in the whole operating range. However, in the high wind speeds region, both controllers were unable to deliver the rpm requirements. We proposed the use of neural network intelligent techniques to supply us the optimal pitch. Our aim was to develop a simple and reliable controller that can deliver this optimal output, while remaining adaptive to system uncertainties and disturbances. The proposed fuzzy controller with a neural pitch controller showed best dynamic and robust performance as compared to the adaptive pitch controller together with the PI exciter. This study has shown that artificial neural networks and fuzzy logic control algorithms can be implemented for real time control implementations. the neuro-fuzzy control approach is robust and its performance is superior to that of traditional control methods. (author)

  5. Role of Bioreactors in Microbial Biomass and Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Liang [Chongqing University, Chongqing, China; Zhang, Biao [Chongqing University, Chongqing, China; Zhu, Xun [Chongqing University, Chongqing, China; Chang, Haixing [Chongqing University of Technology; Ou, Shawn [ORNL; Wang, HONG [Chongqing University, Chongqing, China

    2018-04-01

    Bioenergy is the world’s largest contributor to the renewable and sustainable energy sector, and it plays a significant role in various energy industries. A large amount of research has contributed to the rapidly evolving field of bioenergy and one of the most important topics is the use of the bioreactor. Bioreactors play a critical role in the successful development of technologies for microbial biomass cultivation and energy conversion. In this chapter, after a brief introduction to bioreactors (basic concepts, configurations, functions, and influencing factors), the applications of the bioreactor in microbial biomass, microbial biofuel conversion, and microbial electrochemical systems are described. Importantly, the role and significance of the bioreactor in the bioenergy process are discussed to provide a better understanding of the use of bioreactors in managing microbial biomass and energy conversion.

  6. Standard Terminology Relating to Photovoltaic Solar Energy Conversion

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This terminology pertains to photovoltaic (radiant-to-electrical energy conversion) device performance measurements and is not a comprehensive list of terminology for photovoltaics in general. 1.2 Additional terms used in this terminology and of interest to solar energy may be found in Terminology E 772.

  7. Quantitative feasibility study of magnetocaloric energy conversion utilizing industrial waste heat

    International Nuclear Information System (INIS)

    Vuarnoz, D.; Kitanovski, A.; Gonin, C.; Borgeaud, Y.; Delessert, M.; Meinen, M.; Egolf, P.W.

    2012-01-01

    Highlights: ► We model magnetic energy conversion machine for the use of industrial waste heat. ► Efficiencies and masses of the system are evaluated by a numerical model. ► Excellent potential of profitability is expected with large low-exergy heat sources. -- Abstract: The main objective of this theoretical study was to investigate under which conditions a magnetic energy conversion device (MECD) – utilizing industrial waste heat – is economically feasible. Furthermore, it was evaluated if magnetic energy conversion (MCE) has the potential of being a serious concurrent to already existing conventional energy conversion technologies. Up-today the availability of magnetocaloric materials with a high Curie temperature and a high magnetocaloric effect is rather limited. Therefore, this study was mainly focused on applications with heat sources of low to medium temperature levels. Magnetic energy conversion machines, containing permanent magnets, are numerically investigated for operation conditions with different temperature levels, defined by industrial waste heat sources and environmental heat sinks, different magnetic field intensities and different frequencies of operation (number of thermodynamic cycles per unit of time). Theoretical modeling and numerical simulations were performed in order to determine thermodynamic efficiencies and the exergy efficiencies as function of different operation conditions. From extracted data of our numerical results, approximate values of the total mass and total volume of magnetic energy conversion machines could be determined. These important results are presented dependent on the produced electric power. An economic feasibility study supplements the scientific study. It shows an excellent potential of profitability for certain machines. The most important result of this article is that the magnetic energy conversion technology can be economically and technically competitive to or even beat conventional energy

  8. Conversion of solar energy into heat

    International Nuclear Information System (INIS)

    Devin, B.; Etievant, C.

    1975-01-01

    Argument prevails regarding the main parameters involved in the definition of installations designed to convert by means of a thermal machine, solar energy into electrical or mechanical energy. Between the temperature of the cold source and the stagnation temperature, there exists an optimal temperature which makes for the maximum efficiency of the collector/thermal machine unit. The optimal operating conditions for different types of collector are examined. Optimization of the surface of the collector is dealt with in particular. The structure and cost of solar installations are also analyzed with some examples as basis: solar pumps of 1 to 25kW, a 50MWe electrosolar plant. The cost involves three main elements: the collector, the thermal unit and the heat storage device. The latter is necessary for the integration of diurnal and nocturnal fluctuations of isolation. It is shown that thermal storage is economically payable only under certain conditions [fr

  9. Photovoltaic and photoelectrochemical conversion of solar energy.

    Science.gov (United States)

    Grätzel, Michael

    2007-04-15

    The Sun provides approximately 100,000 terawatts to the Earth which is about 10000 times more than the present rate of the world's present energy consumption. Photovoltaic cells are being increasingly used to tap into this huge resource and will play a key role in future sustainable energy systems. So far, solid-state junction devices, usually made of silicon, crystalline or amorphous, and profiting from the experience and material availability resulting from the semiconductor industry, have dominated photovoltaic solar energy converters. These systems have by now attained a mature state serving a rapidly growing market, expected to rise to 300 GW by 2030. However, the cost of photovoltaic electricity production is still too high to be competitive with nuclear or fossil energy. Thin film photovoltaic cells made of CuInSe or CdTe are being increasingly employed along with amorphous silicon. The recently discovered cells based on mesoscopic inorganic or organic semiconductors commonly referred to as 'bulk' junctions due to their three-dimensional structure are very attractive alternatives which offer the prospect of very low cost fabrication. The prototype of this family of devices is the dye-sensitized solar cell (DSC), which accomplishes the optical absorption and the charge separation processes by the association of a sensitizer as light-absorbing material with a wide band gap semiconductor of mesoporous or nanocrystalline morphology. Research is booming also in the area of third generation photovoltaic cells where multi-junction devices and a recent breakthrough concerning multiple carrier generation in quantum dot absorbers offer promising perspectives.

  10. Carbon nanomaterials for advanced energy conversion and storage.

    Science.gov (United States)

    Dai, Liming; Chang, Dong Wook; Baek, Jong-Beom; Lu, Wen

    2012-04-23

    It is estimated that the world will need to double its energy supply by 2050. Nanotechnology has opened up new frontiers in materials science and engineering to meet this challenge by creating new materials, particularly carbon nanomaterials, for efficient energy conversion and storage. Comparing to conventional energy materials, carbon nanomaterials possess unique size-/surface-dependent (e.g., morphological, electrical, optical, and mechanical) properties useful for enhancing the energy-conversion and storage performances. During the past 25 years or so, therefore, considerable efforts have been made to utilize the unique properties of carbon nanomaterials, including fullerenes, carbon nanotubes, and graphene, as energy materials, and tremendous progress has been achieved in developing high-performance energy conversion (e.g., solar cells and fuel cells) and storage (e.g., supercapacitors and batteries) devices. This article reviews progress in the research and development of carbon nanomaterials during the past twenty years or so for advanced energy conversion and storage, along with some discussions on challenges and perspectives in this exciting field. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Direct Drive Generator for Renewable Power Conversion from Water Currents

    International Nuclear Information System (INIS)

    Segergren, Erik

    2005-01-01

    In this thesis permanent magnet direct drive generator for power conversion from water currents is studied. Water currents as a power source involves a number of constrains as well as possibilities, especially when direct drive and permanent magnets are considered. The high power fluxes and low current velocities of a water current, in combination with its natural variations, will affect the way the generator is operated and, flowingly, the appearance of the generator. The work in this thesis can, thus, be categorized into two general topics, generator technology and optimization. Under the first topic, fundamental generator technology is used to increase the efficiency of a water current generator. Under the latter topic, water current generators are optimized to a specific environment. The conclusion drawn from this work is that it is possible to design very low speed direct drive generators with good electromagnetic properties and wide efficiency peak

  12. Questions of economics. [solar energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Graeff, P

    1976-05-01

    The essay deals with questions of profitability in connection with the use of solar energy to heat buildings or to prepare hot water. The total problem is approached from 3 points of view: 1. General national economy point of view: Judgment by politicians determines the possibilities of support by the government. 2. The business economy aspect: Here the most important matter is to construct the plants with dimensions permitting to obtain the highest profits possible. 3. The financing model: possible incentives must be taken into consideration as well as technical aspects, e.g. the service life of the plants.

  13. Solar power conversion system with directionally- and spectrally-selective properties based on a reflective cavity

    Science.gov (United States)

    Boriskina, Svetlana; Kraemer, Daniel; McEnaney, Kenneth; Weinstein, Lee A.; Chen, Gang

    2018-03-13

    Solar power conversion system. The system includes a cavity formed within an enclosure having highly specularly reflecting in the IR spectrum inside walls, the enclosure having an opening to receive solar radiation. An absorber is positioned within the cavity for receiving the solar radiation resulting in heating of the absorber structure. In a preferred embodiment, the system further contains an energy conversion and storage devices thermally-linked to the absorber by heat conduction, convection, far-field or near-field thermal radiation.

  14. Understanding and exploiting optical properties in semiconductor nanowires for solar energy conversion

    DEFF Research Database (Denmark)

    Frau, Eleonora; Tutuncuoglu, Gozde; Matteini, Federico

    2016-01-01

    Semiconductor nanowires are promising building blocks for next generation solar energy conversion at low cost, due to their large absorption cross-sections. Here, the understanding of their absorption power is explored via computational and experimental methods as well as its use in other fields...

  15. Polyaniline (PANi based electrode materials for energy storage and conversion

    Directory of Open Access Journals (Sweden)

    Huanhuan Wang

    2016-09-01

    Full Text Available Polyaniline (PANi as one kind of conducting polymers has been playing a great role in the energy storage and conversion devices besides carbonaceous materials and metallic compounds. Due to high specific capacitance, high flexibility and low cost, PANi has shown great potential in supercapacitor. It alone can be used in fabricating an electrode. However, the inferior stability of PANi limits its application. The combination of PANi and other active materials (carbon materials, metal compounds or other polymers can surpass these intrinsic disadvantages of PANi. This review summarizes the recent progress in PANi based composites for energy storage/conversion, like application in supercapacitors, rechargeable batteries, fuel cells and water hydrolysis. Besides, PANi derived nitrogen-doped carbon materials, which have been widely employed as carbon based electrodes/catalysts, are also involved in this review. PANi as a promising material for energy storage/conversion is deserved for intensive study and further development.

  16. Optimizing Energy Conversion: Magnetic Nano-materials

    Science.gov (United States)

    McIntyre, Dylan; Dann, Martin; Ilie, Carolina C.

    2015-03-01

    We present herein the work started at SUNY Oswego as a part of a SUNY 4E grant. The SUNY 4E Network of Excellence has awarded SUNY Oswego and collaborators a grant to carry out extensive studies on magnetic nanoparticles. The focus of the study is to develop cost effective rare-earth-free magnetic materials that will enhance energy transmission performance of various electrical devices (solar cells, electric cars, hard drives, etc.). The SUNY Oswego team has started the preliminary work for the project and graduate students from the rest of the SUNY 4E team (UB, Alfred College, Albany) will continue the project. The preliminary work concentrates on analyzing the properties of magnetic nanoparticle candidates, calculating molecular orbitals and band gap, and the fabrication of thin films. SUNY 4E Network of Excellence Grant.

  17. Functionalization of graphene for efficient energy conversion and storage.

    Science.gov (United States)

    Dai, Liming

    2013-01-15

    As global energy consumption accelerates at an alarming rate, the development of clean and renewable energy conversion and storage systems has become more important than ever. Although the efficiency of energy conversion and storage devices depends on a variety of factors, their overall performance strongly relies on the structure and properties of the component materials. Nanotechnology has opened up new frontiers in materials science and engineering to meet this challenge by creating new materials, particularly carbon nanomaterials, for efficient energy conversion and storage. As a building block for carbon materials of all other dimensionalities (such as 0D buckyball, 1D nanotube, 3D graphite), the two-dimensional (2D) single atomic carbon sheet of graphene has emerged as an attractive candidate for energy applications due to its unique structure and properties. Like other materials, however, a graphene-based material that possesses desirable bulk properties rarely features the surface characteristics required for certain specific applications. Therefore, surface functionalization is essential, and researchers have devised various covalent and noncovalent chemistries for making graphene materials with the bulk and surface properties needed for efficient energy conversion and storage. In this Account, I summarize some of our new ideas and strategies for the controlled functionalization of graphene for the development of efficient energy conversion and storage devices, such as solar cells, fuel cells, supercapacitors, and batteries. The dangling bonds at the edge of graphene can be used for the covalent attachment of various chemical moieties while the graphene basal plane can be modified via either covalent or noncovalent functionalization. The asymmetric functionalization of the two opposite surfaces of individual graphene sheets with different moieties can lead to the self-assembly of graphene sheets into hierarchically structured materials. Judicious

  18. Rare-earth magnet applications in energy conversion

    International Nuclear Information System (INIS)

    Tripathi, K.C.

    1998-01-01

    In recent years there has been considerable progress in the field of development and variety of new applications of rare-earth and rare-earth transition metal magnets. High energy content Nd-Fe-B magnet system which competes with superconducting magnets is very promising for the use in energy conversion machines, levitation systems, magnetic resonance investigation and other magnetic applications. Energy conversion machines such as motors and generators are of interest in this context. Motor converts electrical energy into mechanical energy using permanent magnets and ferromagnetic materials as its components. Electric generator converts mechanical energy into electricity using permanent magnets and ferromagnetic material. In both cases symmetry and symmetry breaking play an important role. Symmetry exists above curie temperature, as temperature is lowered symmetry is broken due to spontaneous magnetisation. Author and coworkers developed some new and highest efficiency, permanent magnet based, electronically controlled, dynamically synchronised pulsed dc linear and rotational motors which are briefly described here. Based on such experience and considering field interactions inside material under dynamical conditions and special geometrical situations, order-disorder processes, symmetry breaking and energy transfer on the basis of manifold aspects as a cooperative many body interaction, thermal fluctuations, zero-point energy, dissipation of energy, entropy exchange are discussed in context of conversion of environmental heat into electricity as suggested by Tripathi earlier. (orig.)

  19. Light energy conversion by photocatalytic reaction

    Energy Technology Data Exchange (ETDEWEB)

    Fujishima, Akira; Yamagata, Sadamu [Univ. of Tokyo (Japan)

    1989-01-01

    The photocatalytic reaction, to be made to a suspended semiconductor powder system, was explained in summary. By using semiconductor as an electrode for the electrolyzation, etc. and projecting light on it to generate photoelectromotive force, a photocell can be composed. eg., by composing titanium oxide electrode, n-type semiconductor and platinum electrode, and irradiating light on the former electrode to generate electric current, oxygen and hydrogen are produced from the titanium oxide electrode and platinum electrode, respectively, which means the possibility of obtainment of clean energy from water as raw material. Such a wet type photocell, easy to produce, is active also in research. With white titanium oxide powder being suspended in water solution, hydrogen is produced by projecting light into it. Such a semiconductor is called photocatalyst, in which the research has been widely developed, mainly by taking notice of the hydrogen production on reduction side, since 1972. The photocatalysis using colloid and, differently, that doing heteropolyacid are also taken notice of. 24 refs., 6 figs.

  20. GaN transistors for efficient power conversion

    CERN Document Server

    Lidow, Alex; de Rooij, Michael; Reusch, David

    2014-01-01

    The first edition of GaN Transistors for Efficient Power Conversion was self-published by EPC in 2012, and is currently the only other book to discuss GaN transistor technology and specific applications for the technology. More than 1,200 copies of the first edition have been sold through Amazon or distributed to selected university professors, students and potential customers, and a simplified Chinese translation is also available. The second edition has expanded emphasis on applications for GaN transistors and design considerations. This textbook provides technical and application-focused i

  1. Photoassisted electrolysis of water - Conversion of optical to chemical energy

    Science.gov (United States)

    Wrighton, M. S.; Bolts, J. M.; Kaiser, S. W.; Ellis, A. B.

    1976-01-01

    A description is given of devices, termed photoelectrochemical cells, which can, in principle, be used to directly convert light to fuels and/or electricity. The fundamental principles on which the photoelectrochemical cell is based are related to the observation that irradiation of a semiconductor electrode in an electrochemical cell can result in the flow of an electric current in the external circuit. Attention is given to the basic mechanisms involved, the energy conversion efficiency, the advantages of photoelectrochemical cells, and the results of investigations related to the study of energy conversion via photoelectrochemical cells.

  2. Nanogold plasmonic photocatalysis for organic synthesis and clean energy conversion.

    Science.gov (United States)

    Wang, Changlong; Astruc, Didier

    2014-01-01

    This review provides the basic concepts, an overall survey and the state-of-the art of plasmon-based nanogold photocatalysis using visible light including fundamental understanding and major applications to organic reactions and clean energy-conversion systems. First, the basic concepts of localized surface plasmon resonance (LSPR) are recalled, then the major preparation methods of AuNP-based plasmonic photocatalysts are reviewed. The major part of the review is dedicated to the latest progress in the application of nanogold plasmonic photocatalysis to organic transformations and energy conversions, and the proposed mechanisms are discussed. In conclusion, new challenges and perspectives are proposed and analyzed.

  3. A review of electrohydrodynamic casting energy conversion polymer composites

    Directory of Open Access Journals (Sweden)

    Yong X. Gan

    2018-03-01

    Full Text Available This paper provides a brief review on manufacturing polymer composite materials through the nontraditional electrohydrodynamic (EHD casting approach. First, the EHD technology will be introduced. Then, typical functional polymer composite materials including thermoelectric and photoelectric energy conversion polymers and their composites will be presented. Specifically, how to make composite materials containing functional nanoparticles will be discussed. Converting polymeric fibers into partially carbonized fiber composites will also be shown. The latest research results of polymeric composite materials with energy conversion and sensing functions will be given.

  4. Direct energy conversion system for D-3He fusion

    International Nuclear Information System (INIS)

    Tomita, Y.; Shu, L.Y.; Momota, H.

    1993-11-01

    A novel and highly efficient direct energy conversion system is proposed for utilizing D- 3 He fueled fusion. In order to convert kinetic energy of ions, we applied a pair of direct energy conversion systems each of which has a cusp-type DEC and a traveling wave DEC (TWDEC). In a cusp-type DEC, electrons are separated from the escaping ions at the first line-cusp and the energy of thermal ion components is converted at the second cusp DEC. The fusion protons go through the cusp-type DEC and arrive at the TWDEC, which principle is similar to 'LINAC.' The energy of fusion protons is recovered to electricity with an efficiency of more than 70%. These DECs bring about the high efficient fusion plant. (author)

  5. Decoupling energy and power

    Science.gov (United States)

    Grattieri, Matteo; Minteer, Shelley D.

    2018-01-01

    Biological photovoltaic devices (BPVs) use photosynthetic microorganisms to produce electricity, but low photocurrent generation impedes their application. Now, a micro-scale flow-based BPV system is reported with power density outputs similar to that of large-scale biofuels.

  6. Study of electron beam energy conversion at gyrocon-linear accelerator facility

    International Nuclear Information System (INIS)

    Karliner, M.M.; Makarov, I.G.; Ostreiko, G.N.

    2004-01-01

    A gyrocon together with the high-voltage 1.5 MeV accelerator ELIT-3A represents a power generator at 430 MHz serving for linear electron accelerator pulse driving. The facility description and results of calorimetric measurements of ELIT-3A electron beam power and accelerated beam at the end of accelerator are presented in the paper. The achieved energy conversion efficiency is about 55%

  7. Nuclear power and energy planning

    International Nuclear Information System (INIS)

    Jones, P.

    1990-11-01

    With the rapid depletion of conventional energy sources such as coal and oil and the growing world demand for energy the question of how to provide the extra energy needed in the future is addressed. Relevant facts and figures are presented. Coal and oil have disadvantages as their burning contributes to the greenhouse gases and they will become scarcer and more expensive. Renewable sources such as wind and wave power can supply some but not all future energy requirements. The case made for nuclear power is that it is the only source which offers the long term prospect of meeting the growing world energy demand whilst keeping energy costs close to present levels and which does not add to atmospheric pollution. Reassurance as to the safety of nuclear power plants and the safe disposal of radioactive wastes is given. (UK)

  8. Challenges of Iran's energy conversion agreements in future competitive market

    International Nuclear Information System (INIS)

    Sobhiyah, M.H.; Kashtiban, Y.Kh.

    2008-01-01

    Extensive need for electricity and lack of enough governmental resources for the development of related infrastructures forced the Iranian Government to invite private investors and to sign Energy Conversion Agreement (ECA) in the form of build-operate-transfer (BOT) and build-operate-own (BOO) contracts with them. Accordingly, electricity purchase would be based on a guaranteed price. Changes in some laws in 2007 caused the management of the ECAs and electricity purchase based on guaranteed price to face challenges. Shortening the commercial operation period of the earlier ECAs and signing some new short-term ECAs were the steps taken by the authorities to resolve the problems. By shortening the ECAs' commercial operation period, it is likely to cause serious problems concerning the payments of the project companies, because of shortages in the government's financial resources. The findings of the present viewpoint suggest signing of new long-term contracts (20 years long) in the form of a combinational agreement for buying the produced electricity with a guaranteed price (in the first 5 years) and supplying it in the competitive power market (for the following years) would be a better way to reduce the problems

  9. Maximum Efficiency of Thermoelectric Heat Conversion in High-Temperature Power Devices

    Directory of Open Access Journals (Sweden)

    V. I. Khvesyuk

    2016-01-01

    Full Text Available Modern trends in development of aircraft engineering go with development of vehicles of the fifth generation. The features of aircrafts of the fifth generation are motivation to use new high-performance systems of onboard power supply. The operating temperature of the outer walls of engines is of 800–1000 K. This corresponds to radiation heat flux of 10 kW/m2 . The thermal energy including radiation of the engine wall may potentially be converted into electricity. The main objective of this paper is to analyze if it is possible to use a high efficiency thermoelectric conversion of heat into electricity. The paper considers issues such as working processes, choice of materials, and optimization of thermoelectric conversion. It presents the analysis results of operating conditions of thermoelectric generator (TEG used in advanced hightemperature power devices. A high-temperature heat source is a favorable factor for the thermoelectric conversion of heat. It is shown that for existing thermoelectric materials a theoretical conversion efficiency can reach the level of 15–20% at temperatures up to 1500 K and available values of Ioffe parameter being ZT = 2–3 (Z is figure of merit, T is temperature. To ensure temperature regime and high efficiency thermoelectric conversion simultaneously it is necessary to have a certain match between TEG power, temperature of hot and cold surfaces, and heat transfer coefficient of the cooling system. The paper discusses a concept of radiation absorber on the TEG hot surface. The analysis has demonstrated a number of potentialities for highly efficient conversion through using the TEG in high-temperature power devices. This work has been implemented under support of the Ministry of Education and Science of the Russian Federation; project No. 1145 (the programme “Organization of Research Engineering Activities”.

  10. Theoretical studies of thermionic conversion of solar energy with graphene as emitter and collector

    Science.gov (United States)

    Olawole, Olukunle C.; De, Dilip Kumar

    2018-01-01

    Thermionic energy conversion (TEC) using nanomaterials is an emerging field of research. It is known that graphene can withstand temperatures as high as 4600 K in vacuum, and it has been shown that its work function can be engineered from a high value (for monolayer/bilayer) of 4.6 eV to as low as 0.7 eV. Such attractive electronic properties (e.g., good electrical conductivity and high dielectric constant) make engineered graphene a good candidate as an emitter and collector in a thermionic energy converter for harnessing solar energy efficiently. We have used a modified Richardson-Dushman equation and have adopted a model where the collector temperature could be controlled through heat extraction in a calculated amount and a magnet can be attached on the back surface of the collector for future control of the space-charge effect. Our work shows that the efficiency of solar energy conversion also depends on power density falling on the emitter surface, and that a power conversion efficiency of graphene-based solar TEC as high as 55% can be easily achieved (in the absence of the space-charge effect) through proper choice of work functions, collector temperature, and emissivity of emitter surfaces. Such solar energy conversion would reduce our dependence on silicon solar panels and offers great potential for future renewable energy utilization.

  11. 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.

  12. Power Conversion Study for High Temperature Gas-Cooled Reactors

    International Nuclear Information System (INIS)

    Chang Oh; Richard Moore; Robert Barner

    2005-01-01

    The Idaho National Laboratory (INL) is investigating a Brayton cycle efficiency improvement on a high temperature gas-cooled reactor (HTGR) as part of Generation-IV nuclear engineering research initiative. There are some technical issues to be resolved before the selection of the final design of the high temperature gas cooled reactor, called as a Next Generation Nuclear Plant (NGNP), which is supposed to be built at the INEEL by year 2017. The technical issues are the selection of the working fluid, direct vs. indirect cycle, power cycle type, the optimized design in terms of a number of intercoolers, and others. In this paper, we investigated a number of working fluids for the power conversion loop, direct versus indirect cycle, the effect of intercoolers, and other thermal hydraulics issues. However, in this paper, we present part of the results we have obtained. HYSYS computer code was used along with a computer model developed using Visual Basic computer language

  13. High efficiency heat transport and power conversion system for cascade

    International Nuclear Information System (INIS)

    Maya, I.; Bourque, R.F.; Creedon, R.L.; Schultz, K.R.

    1985-02-01

    The Cascade ICF reactor features a flowing blanket of solid BeO and LiAlO 2 granules with very high temperature capability (up to approx. 2300 K). The authors present here the design of a high temperature granule transport and heat exchange system, and two options for high efficiency power conversion. The centrifugal-throw transport system uses the peripheral speed imparted to the granules by the rotating chamber to effect granule transport and requires no additional equipment. The heat exchanger design is a vacuum heat transfer concept utilizing gravity-induced flow of the granules over ceramic heat exchange surfaces. A reference Brayton power cycle is presented which achieves 55% net efficiency with 1300 K peak helium temperature. A modified Field steam cycle (a hybrid Rankine/Brayton cycle) is presented as an alternate which achieves 56% net efficiency

  14. A solar simulator-pumped gas laser for the direct conversion of solar energy

    Science.gov (United States)

    Weaver, W. R.; Lee, J. H.

    1981-01-01

    Most proposed space power systems are comprised of three general stages, including the collection of the solar radiation, the conversion to a useful form, and the transmission to a receiver. The solar-pumped laser, however, effectively eliminates the middle stage and offers direct photon-to-photon conversion. The laser is especially suited for space-to-space power transmission and communication because of minimal beam spread, low power loss over large distances, and extreme energy densities. A description is presented of the first gas laser pumped by a solar simulator that is scalable to high power levels. The lasant is an iodide C3F7I that as a laser-fusion driver has produced terawatt peak power levels.

  15. Coal conversion process by the United Power Plants of Westphalia

    Energy Technology Data Exchange (ETDEWEB)

    1974-08-01

    The coal conversion process used by the United Power Plants of Westphalia and its possible applications are described. In this process, the crushed and predried coal is degassed and partly gasified in a gas generator, during which time the sulfur present in the coal is converted into hydrogen sulfide, which together with the carbon dioxide is subsequently washed out and possibly utilized or marketed. The residual coke together with the ashes and tar is then sent to the melting chamber of the steam generator where the ashes are removed. After desulfurization, the purified gas is fed into an external circuit and/or to a gas turbine for electricity generation. The raw gas from the gas generator can be directly used as fuel in a conventional power plant. The calorific value of the purified gas varies from 3200 to 3500 kcal/cu m. The purified gas can be used as reducing agent, heating gas, as raw material for various chemical processes, or be conveyed via pipelines to remote areas for electricity generation. The conversion process has the advantages of increased economy of electricity generation with desulfurization, of additional gas generation, and, in long-term prospects, of the use of the waste heat from high-temperature nuclear reactors for this process.

  16. Mirror hybrid reactor blanket and power conversion system conceptual design

    International Nuclear Information System (INIS)

    Schultz, K.R.; Backus, G.A.; Baxi, C.B.; Dee, J.B.; Estrine, E.A.; Rao, R.; Veca, A.R.

    1976-01-01

    The conceptual design of the blanket and power conversion system for a gas-cooled mirror hybrid fusion-fission reactor is presented. The designs of the fuel, blanket module and power conversion system are based on existing gas-cooled fission reactor technology that has been developed at General Atomic Company. The uranium silicide fuel is contained in Inconel-clad rods and is cooled by helium gas. The fuel is contained in 16 spherical segment modules which surround the fusion plasma. The hot helium is used to raise steam for a conventional steam cycle turbine generator. The details of the method of support for the massive blanket modules and helium ducts remain to be determined. Nevertheless, the conceptual design appears to be technically feasible with existing gas-cooled technology. A preliminary safety analysis shows that with the development of a satisfactory method of primary coolant circuit containment and support, the hybrid reactor could be licensed under existing Nuclear Regulatory Commission regulations

  17. Numerical Simulation of Energy Conversion Mechanism in Electric Explosion

    Science.gov (United States)

    Wanjun, Wang; Junjun, Lv; Mingshui, Zhu; Qiubo, Fu; EFIs Integration R&D Group Team

    2017-06-01

    Electric explosion happens when micron-scale metal films such as copper film is stimulated by short-time current pulse, while generating high temperature and high pressure plasma. The expansion process of the plasma plays an important role in the study of the generation of shock waves and the study of the EOS of matter under high pressure. In this paper, the electric explosion process is divided into two stages: the energy deposition stage and the quasi-isentropic expansion stage, and a dynamic EOS of plasma considering the energy replenishment is established. On this basis, flyer driven by plasma is studied numerically, the pressure and the internal energy of plasma in the energy deposition stage and the quasi - isentropic expansion stage are obtained by comparing the velocity history of the flyer with the experimental results. An energy conversion model is established, and the energy conversion efficiency of each process is obtained, and the influence of impedance matching relationship between flyer and metal plasma on the energy conversion efficiency is proposed in this paper.

  18. Electronic Power Transformer Control Strategy in Wind Energy Conversion Systems for Low Voltage Ride-through Capability Enhancement of Directly Driven Wind Turbines with Permanent Magnet Synchronous Generators (D-PMSGs

    Directory of Open Access Journals (Sweden)

    Hui Huang

    2014-11-01

    Full Text Available This paper investigates the use of an Electronic Power Transformer (EPT incorporated with an energy storage system to smooth the wind power fluctuations and enhance the low voltage ride-through (LVRT capability of directly driven wind turbines with permanent magnet synchronous generators (D-PMSGs. The decoupled control schemes of the system, including the grid side converter control scheme, generator side converter control scheme and the control scheme of the energy storage system, are presented in detail. Under normal operating conditions, the energy storage system absorbs the high frequency component of the D-PMSG output power to smooth the wind power fluctuations. Under grid fault conditions, the energy storage system absorbs the redundant power, which could not be transferred to the grid by the EPT, to help the D-PMSG to ride through low voltage conditions. This coordinated control strategy is validated by simulation studies using MATLAB/Simulink. With the proposed control strategy, the output wind power quality is improved and the D-PMSG can ride through severe grid fault conditions.

  19. A current controlled matrix converter for wind energy conversion systems based on permanent magnet synchronous generator

    OpenAIRE

    Naggar H. Saad; Ahmed A. El-Sattar; Mohamed I. Marei

    2016-01-01

    The main challenges of wind energy conversion systems (WECS) are to maximize the energy capture from the wind and injecting reactive power during the fault. This paper presents a current controlled matrix converter to interface Permanent Magnet Synchronous Generators (PMSG) based WECS with the grid. To achieve fast dynamic response with reduced current ripples, a hysteresis current control is utilized. The proposed control system decouples the active and reactive components of the PMSG curren...

  20. Energy discharge heater power supply

    International Nuclear Information System (INIS)

    Jaskierny, W.

    1992-11-01

    The heater power supply is intended to supply capacitively stored,energy to embedded heater strips in cryo magnets. The amount of energy can be controlled by setting different charge different capacitor values. Two chassis' can be operated in series or interlocks are provided. The charge voltage, number of capacitors pulse can be monitored. There and dual channel has two discharge supplies in one chassis. This report reviews the characteristics of this power supply further

  1. Piezoelectric ribbons printed onto rubber for flexible energy conversion.

    Science.gov (United States)

    Qi, Yi; Jafferis, Noah T; Lyons, Kenneth; Lee, Christine M; Ahmad, Habib; McAlpine, Michael C

    2010-02-10

    The development of a method for integrating highly efficient energy conversion materials onto stretchable, biocompatible rubbers could yield breakthroughs in implantable or wearable energy harvesting systems. Being electromechanically coupled, piezoelectric crystals represent a particularly interesting subset of smart materials that function as sensors/actuators, bioMEMS devices, and energy converters. Yet, the crystallization of these materials generally requires high temperatures for maximally efficient performance, rendering them incompatible with temperature-sensitive plastics and rubbers. Here, we overcome these limitations by presenting a scalable and parallel process for transferring crystalline piezoelectric nanothick ribbons of lead zirconate titanate from host substrates onto flexible rubbers over macroscopic areas. Fundamental characterization of the ribbons by piezo-force microscopy indicates that their electromechanical energy conversion metrics are among the highest reported on a flexible medium. The excellent performance of the piezo-ribbon assemblies coupled with stretchable, biocompatible rubber may enable a host of exciting avenues in fundamental research and novel applications.

  2. Energy conversion of biomass in coping with global warming

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Shin-ya; Ogi, Tomoko; Minowa, Tomoaki [National Inst. for Resources and Environment, Tsukuba, Ibaraki (Japan)

    1993-12-31

    The main purpose of the present paper is to propose energy conversion technologies of biomass in coping with global warming. Among thermochemical conversion, liquid fuel production by high pressure process is mainly introduced. Biomass is a term used to describe materials of biological origin, either purpose-grown or arising as by-products, residues or wastes from forestry, agriculture and food processing. Such biomass is a renewable energy sources dependent on solar energy. Through photosynthesis, plants converts carbon dioxide into organic materials used in their growth. Energy can be recovered from the plant materials by several processes, the simplest way is burning in air. As far as biomass is used in this way, there is no atmospheric accumulation of carbon dioxide making no effect on the Greenhouse Effect, provided that the cycle of regrowth and burning is sustained.

  3. Gate controlled high efficiency ballistic energy conversion system

    NARCIS (Netherlands)

    Xie, Yanbo; Bos, Diederik; de Boer, Hans L.; van den Berg, Albert; Eijkel, Jan C.T.; Zengerle, R.

    2013-01-01

    Last year we demonstrated the microjet ballistic energy conversion system[1]. Here we show that the efficiency of such a system can be further improved by gate control. With gate control the electrical current generation is enhanced a hundred times with respect to the current generated from the zeta

  4. Exploring driving forces and liquid properties for electrokinetic energy conversion

    NARCIS (Netherlands)

    Nguyen, Trieu

    2015-01-01

    This thesis presents an effort to understand electrokinetic energy conversion systems which are based on motion of ionic charges in micro- and nano-confinements. In particular, both experimentally and theoretically the utilization of different kind of liquids was investigated to convert mechanical

  5. Solar Program Assessment: Environmental Factors - Ocean Thermal Energy Conversion.

    Science.gov (United States)

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    This report presents the environmental problems which may arise with the further development of Ocean Thermal Energy Conversion, one of the eight Federally-funded solar technologies. To provide a background for this environmental analysis, the history and basic concepts of the technology are reviewed, as are its economic and resource requirements.…

  6. 20 years' 'Department of Energy Conversion' and its contribution to the use of nuclear energy in the GDR

    International Nuclear Information System (INIS)

    Schramm, G.

    1989-01-01

    The Department of Energy Conversion at the Dresden University of Technology has been founded 20 years ago. After briefly elucidating the tasks of the department, a review of scientific achievements carried out to the use of nuclear energy in the power economy of the GDR in this period is given. Results include specific problems of nuclear technology and machine engineering, measurement technology, automation, process design, thermodynamics as well. Further information may be found in the 100 detailed references quoted. (author)

  7. Plasma-assisted CO2 conversion: optimizing performance via microwave power modulation

    Science.gov (United States)

    Britun, Nikolay; Silva, Tiago; Chen, Guoxing; Godfroid, Thomas; van der Mullen, Joost; Snyders, Rony

    2018-04-01

    Significant improvement in the energy efficiency of plasma-assisted CO2 conversion is achieved with applied power modulation in a surfaguide microwave discharge. The obtained values of CO2 conversion and energy efficiency are, respectively, 0.23 and 0.33 for a 0.95 CO2  +  0.05 N2 gas mixture. Analysis of the energy relaxation mechanisms shows that power modulation can potentially affect the vibrational-translational energy exchange in plasma. In our case, however, this mechanism does not play a major role, likely due to the low degree of plasma non-equilibrium in the considered pressure range. Instead, the gas residence time in the discharge active zone together with plasma pulse duration are found to be the main factors affecting the CO2 conversion efficiency at low plasma pulse repetition rates. This effect is confirmed experimentally by the in situ time-resolved two-photon absorption laser-induced fluorescence measurements of CO molecular density produced in the discharge as a result of CO2 decomposition.

  8. Reactive Power from Distributed Energy

    Energy Technology Data Exchange (ETDEWEB)

    Kueck, John; Kirby, Brendan; Rizy, Tom; Li, Fangxing; Fall, Ndeye

    2006-12-15

    Distributed energy is an attractive option for solving reactive power and distribution system voltage problems because of its proximity to load. But the cost of retrofitting DE devices to absorb or produce reactive power needs to be reduced. There also needs to be a market mechanism in place for ISOs, RTOs, and transmission operators to procure reactive power from the customer side of the meter where DE usually resides. (author)

  9. Reactive Power from Distributed Energy

    International Nuclear Information System (INIS)

    Kueck, John; Kirby, Brendan; Rizy, Tom; Li, Fangxing; Fall, Ndeye

    2006-01-01

    Distributed energy is an attractive option for solving reactive power and distribution system voltage problems because of its proximity to load. But the cost of retrofitting DE devices to absorb or produce reactive power needs to be reduced. There also needs to be a market mechanism in place for ISOs, RTOs, and transmission operators to procure reactive power from the customer side of the meter where DE usually resides. (author)

  10. Energy neutral and low power wireless communications

    Science.gov (United States)

    Orhan, Oner

    Wireless sensor nodes are typically designed to have low cost and small size. These design objectives impose restrictions on the capacity and efficiency of the transceiver components and energy storage units that can be used. As a result, energy becomes a bottleneck and continuous operation of the sensor network requires frequent battery replacements, increasing the maintenance cost. Energy harvesting and energy efficient transceiver architectures are able to overcome these challenges by collecting energy from the environment and utilizing the energy in an intelligent manner. However, due to the nature of the ambient energy sources, the amount of useful energy that can be harvested is limited and unreliable. Consequently, optimal management of the harvested energy and design of low power transceivers pose new challenges for wireless network design and operation. The first part of this dissertation is on energy neutral wireless networking, where optimal transmission schemes under different system setups and objectives are investigated. First, throughput maximization for energy harvesting two-hop networks with decode-and-forward half-duplex relays is studied. For a system with two parallel relays, various combinations of the following four transmission modes are considered: Broadcast from the source, multi-access from the relays, and successive relaying phases I and II. Next, the energy cost of the processing circuitry as well as the transmission energy are taken into account for communication over a broadband fading channel powered by an energy harvesting transmitter. Under this setup, throughput maximization, energy maximization, and transmission completion time minimization problems are studied. Finally, source and channel coding for an energy-limited wireless sensor node is investigated under various energy constraints including energy harvesting, processing and sampling costs. For each objective, optimal transmission policies are formulated as the solutions of a

  11. Progress on PEP-II magnet power conversion system

    International Nuclear Information System (INIS)

    Bellomo, P.; Genova, L.; Jackson, T.; Shimer, D.

    1996-01-01

    The various power systems for supplying the PEP-II DC magnets rely exclusively on switchmode conversion, utilizing a variety of means depending on the requirements. All of the larger power supplies, ranging from 10 to 200 kW, are powered from DC sources utilizing rectified 480 V AC. Choppers can be used for the series connected strings, but for smaller groups and individual magnets, inverters driving high-frequency transformers with rectifiers comprise the best approach. All of the various systems use a ''building block'' approach of multiple standard-size units connected in series or parallel to most cost-effectively deal with a great range of voltage and current requirements. Utilization of existing infrastructure from PEP-I has been a cost-effective determinant. Equipment is being purchased either off-the-shelf, through performance specification, or by hardware purchase based on design-through-prototype. The corrector magnet power system, utilizing inexpensive, off-the-shelf, four-quadrant switching motor-controllers, has already proven very reliable: 120 of the total of 900 units have been running on the injection system for four months with no failures

  12. Progress on PEP-II magnet power conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Bellomo, P.; Genova, L. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Jackson, T. [Lawrence Berkeley National Lab., CA (United States); Shimer, D. [Lawrence Livermore National Lab., CA (United States)

    1996-06-04

    The various power systems for supplying the PEP-II DC magnets rely exclusively on switchmode conversion, utilizing a variety of means depending on the requirements. All of the larger power supplies, ranging from 10 to 200 kW, are powered from DC sources utilizing rectified 480 V AC. Choppers can be used for the series connected strings, but for smaller groups and individual magnets, inverters driving high-frequency transformers with rectifiers comprise the best approach. All of the various systems use a ``building block`` approach of multiple standard-size units connected in series or parallel to most cost-effectively deal with a great range of voltage and current requirements. Utilization of existing infrastructure from PEP-I has been a cost-effective determinant. Equipment is being purchased either off-the-shelf, through performance specification, or by hardware purchase based on design-through-prototype. The corrector magnet power system, utilizing inexpensive, off-the-shelf, four-quadrant switching motor-controllers, has already proven very reliable: 120 of the total of 900 units have been running on the injection system for four months with no failures.

  13. Optimization of Aeolian Energy Conversion Optimisation de la ...

    African Journals Online (AJOL)

    The use of renewable energy increases, because people are increasingly concerned with environmental issues. Among renewable, wind power is now widely used. Their study showed that a value of wind speed, there is a maximum mechanical power supplied by the turbine. So, power is supplied are particularly changes ...

  14. Power Converters and Control of Renewable Energy Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Teodorescu, Remus; Chen, Zhe

    2004-01-01

    The global electrical energy consumption is steadily rising and therefore a continuous demand to increase the power generation capacity. A significant percentage of the required capacity increase can be based on renewable energy sources. Wind turbine technology, as the most cost effective renewable...... energy conversion system, will play an important part in our future energy supply. But other sources like microturbines, photovoltaics and fuel cell systems may also be serious contributor to the power supply. Characteristically, power electronics will be an efficient and important interface to the grid...... for the renewables and this paper will first briefly discuss three different alternative/renewable energy sources. Next, various configurations of small and medium power conversion topologies are presented including their control (mainly for PV-systems). Finally wind turbine configuration and their control...

  15. Nano Sensing and Energy Conversion Using Surface Plasmon Resonance (SPR

    Directory of Open Access Journals (Sweden)

    Iltai (Isaac Kim

    2015-07-01

    Full Text Available Nanophotonic technique has been attracting much attention in applications of nano-bio-chemical sensing and energy conversion of solar energy harvesting and enhanced energy transfer. One approach for nano-bio-chemical sensing is surface plasmon resonance (SPR imaging, which can detect the material properties, such as density, ion concentration, temperature, and effective refractive index in high sensitivity, label-free, and real-time under ambient conditions. Recent study shows that SPR can successfully detect the concentration variation of nanofluids during evaporation-induced self-assembly process. Spoof surface plasmon resonance based on multilayer metallo-dielectric hyperbolic metamaterials demonstrate SPR dispersion control, which can be combined with SPR imaging, to characterize high refractive index materials because of its exotic optical properties. Furthermore, nano-biophotonics could enable innovative energy conversion such as the increase of absorption and emission efficiency and the perfect absorption. Localized SPR using metal nanoparticles show highly enhanced absorption in solar energy harvesting. Three-dimensional hyperbolic metamaterial cavity nanostructure shows enhanced spontaneous emission. Recently ultrathin film perfect absorber is demonstrated with the film thickness is as low as ~1/50th of the operating wavelength using epsilon-near-zero (ENZ phenomena at the wavelength close to SPR. It is expected to provide a breakthrough in sensing and energy conversion applications using the exotic optical properties based on the nanophotonic technique.

  16. High efficiency β radioisotope energy conversion using reciprocating electromechanical converters with integrated betavoltaics

    Science.gov (United States)

    Duggirala, Rajesh; Li, Hui; Lal, Amit

    2008-04-01

    We demonstrate a 5.1% energy conversion efficiency Ni63 radioisotope power generator by integrating silicon betavoltaic converters with radioisotope actuated reciprocating piezoelectric unimorph cantilever converters. The electromechanical energy converter efficiently utilizes both the kinetic energy and the electrical charge of the 0.94μW β radiation from a 9mCi Ni63 thin film source to generate maximum (1) continuous betavoltaic electrical power output of 22nW and (2) pulsed piezoelectric electrical power output of 750μW at 0.07% duty cycle. The electromechanical converters can be potentially used to realize 100year lifetime power sources for powering periodic sampling remote wireless sensor microsystems.

  17. Robust Sliding Mode Control of Permanent Magnet Synchronous Generator-Based Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Guangping Zhuo

    2016-12-01

    Full Text Available The subject of this paper pertains to sliding mode control and its application in nonlinear electrical power systems as seen in wind energy conversion systems. Due to the robustness in dealing with unmodeled system dynamics, sliding mode control has been widely used in electrical power system applications. This paper presents first and high order sliding mode control schemes for permanent magnet synchronous generator-based wind energy conversion systems. The application of these methods for control using dynamic models of the d-axis and q-axis currents, as well as those of the high speed shaft rotational speed show a high level of efficiency in power extraction from a varying wind resource. Computer simulation results have shown the efficacy of the proposed sliding mode control approaches.

  18. Two Level Versus Matrix Converters Performance in Wind Energy Conversion Systems Employing DFIG

    Science.gov (United States)

    Reddy, Gongati Pandu Ranga; Kumar, M. Vijaya

    2017-10-01

    Wind power capacity has received enormous growth during past decades. With substantial development of wind power, it is expected to provide a fifth of world's electricity by the end of 2030. In wind energy conversion system, the power electronic converters play an important role. This paper presents the two level and matrix converters performance in wind energy conversion system employing Doubly Fed Induction Generator (DFIG). The DFIG is a wound rotor induction generator. Because of the advantages of the DFIG over other generators it is being used for most of the wind applications. This paper also discusses control of converters using the space vector pulse width modulation technique. The MATLAB/SIMULINK ® software is used to study the performance of the converters.

  19. Overview of Multi-Kilowatt Free-Piston Stirling Power Conversion Research at Glenn Research Center

    Science.gov (United States)

    Geng, Steven M.; Mason, Lee S.; Dyson, Rodger W.; Penswick, L. Barry

    2008-01-01

    As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors and a pair of commercially available pressure wave generators (which will be plumbed together to create a high power Stirling linear alternator test rig) have been procured for in-house testing at Glenn Research Center (GRC). Delivery of both the Stirling convertors and the linear alternator test rig is expected by October 2007. The 1 kW class free-piston Stirling convertors will be tested at GRC to map and verify performance. The convertors will later be modified to operate with a NaK liquid metal pumped loop for thermal energy input. The high power linear alternator test rig will be used to map and verify high power Stirling linear alternator performance and to develop power management and distribution (PMAD) methods and techniques. This paper provides an overview of the multi-kilowatt free-piston Stirling power conversion work being performed at GRC.

  20. Overview of Multi-kilowatt Free-Piston Stirling Power Conversion Research at GRC

    Science.gov (United States)

    Geng, Steven M.; Mason, Lee S.; Dyson, Rodger W.; Penswick, L. Barry

    2008-01-01

    As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors and a pair of commercially available pressure wave generators (which will be plumbed together to create a high power Stirling linear alternator test rig) have been procured for in-house testing at Glenn Research Center. Delivery of both the Stirling convertors and the linear alternator test rig is expected by October, 2007. The 1 kW class free-piston Stirling convertors will be tested at GRC to map and verify performance. The convertors will later be modified to operate with a NaK liquid metal pumped loop for thermal energy input. The high power linear alternator test rig will be used to map and verify high power Stirling linear alternator performance and to develop power management and distribution (PMAD) methods and techniques. This paper provides an overview of the multi-kilowatt free-piston Stirling power conversion work being performed at GRC.

  1. Overview of Multi-Kilowatt Free-Piston Stirling Power Conversion Research at GRC

    Science.gov (United States)

    Geng, Steven M.; Mason, Lee S.; Dyson, Rodger W.; Penswick, L. Barry

    2008-01-01

    As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors and a pair of commercially available pressure wave generators (which will be plumbed together to create a high power Stirling linear alternator test rig) have been procured for in-house testing at Glenn Research Center. Delivery of both the Stirling convertors and the linear alternator test rig is expected by October, 2007. The 1 kW class free-piston Stirling convertors will be tested at GRC to map and verify performance. The convertors will later be modified to operate with a NaK liquid metal pumped loop for thermal energy input. The high power linear alternator test rig will be used to map and verify high power Stirling linear alternator performance and to develop power management and distribution (PMAD) methods and techniques. This paper provides an overview of the multi-kilowatt free-piston Stirling power conversion work being performed at GRC.

  2. Nuclear reactor closed Brayton cycle power conversion system optimization trends for extra-terrestrial applications

    International Nuclear Information System (INIS)

    Ashe, T.L.; Baggenstoss, W.G.; Bons, R.

    1990-01-01

    Extra-terrestrial exploration and development missions of the next century will require reliable, low-mass power generation modules of 100 kW e and more. These modules will be required to support both fixed-base and manned rover/explorer power needs. Low insolation levels at and beyond Mars and long periods of darkness on the moon make solar conversion less desirable for surface missions. For these missions, a closed Brayton cycle energy conversion system coupled with a reactor heat source is a very attractive approach. The authors conducted parametric studies to assess optimized system design trends for nuclear-Brayton systems as a function of operating environment and user requirements. The inherent design flexibility of the closed Brayton cycle energy conversion system permits ready adaptation of the system to future design constraints. This paper describes a dramatic contrast between system designs requiring man-rated shielding. The paper also considers the ramification of using indigenous materials to provide reactor shielding for a fixed-base power source

  3. Magnetic energy storage and conversion in the solar atmosphere

    Science.gov (United States)

    Spicer, D. S.; Mariska, J. T.; Boris, J. P.

    1986-01-01

    According to the approach employed in this investigation, particularly important simple configurations of magnetic field and plasma are identified, and it is attempted to achieve an understanding of the large-scale dynamic processes and transformations which these systems can undergo. Fundamental concepts are discussed, taking into account aspects of magnetic energy generation, ideal MHD theory, non-MHD properties, the concept of 'anomalous' resistivity, and global electrodynamic coupling. Questions of magnetically controlled energy conversion are examined, giving attention to magnetic modifications of plasma transport, the transition region structure and flows, channeling and acceleration of plasma, channeling and dissipation of MHD waves, and anomalous dissipation of field-aligned currents. A description of the characteristics of magnetohydrodynamic energy conversion is also provided, and outstanding questions are discussed.

  4. Conversion of radius of curvature to power (and vice versa)

    Science.gov (United States)

    Wickenhagen, Sven; Endo, Kazumasa; Fuchs, Ulrike; Youngworth, Richard N.; Kiontke, Sven R.

    2015-09-01

    Manufacturing optical components relies on good measurements and specifications. One of the most precise measurements routinely required is the form accuracy. In practice, form deviation from the ideal surface is effectively low frequency errors, where the form error most often accounts for no more than a few undulations across a surface. These types of errors are measured in a variety of ways including interferometry and tactile methods like profilometry, with the latter often being employed for aspheres and general surface shapes such as freeforms. This paper provides a basis for a correct description of power and radius of curvature tolerances, including best practices and calculating the power value with respect to the radius deviation (and vice versa) of the surface form. A consistent definition of the sagitta is presented, along with different cases in manufacturing that are of interest to fabricators and designers. The results make clear how the definitions and results should be documented, for all measurement setups. Relationships between power and radius of curvature are shown that allow specifying the preferred metric based on final accuracy and measurement method. Results shown include all necessary equations for conversion to give optical designers and manufacturers a consistent and robust basis for decision-making. The paper also gives guidance on preferred methods for different scenarios for surface types, accuracy required, and metrology methods employed.

  5. Tidal energy conversion. Renewable energy; 3-3 choseki / choryu hatsuden. II. saisei kano energy ni yoru hatsuden

    Energy Technology Data Exchange (ETDEWEB)

    Makino, T. [Tobishima Corp., Tokyo (Japan)

    1998-10-15

    There are not much examples applying tidal energy conversion, but tide and tidal current phenomena can be forecasted so correctly regardless of weather that the applying tidal energy is to be expected in the future. The largest tidal power plant is at Reims in France and install 24 Kaplan turbines each of which outlet power is 10,000kW (rotational direction is reversible) on the breakwater (750m is length). Tidal range at this place being 8.5m on an average, during the period of flowing seawater into the reservoir and on the contrary during the period of discharging seawater to the sea generation is both performed. Though there is no actual result of tidal power plant in Japan, in tidal current power system experimental generators have been installed at Kurushima channel and Naruto channel. Nihon University carried out various kinds of experiment using a Darius turbine (1.6m in dia.) at Kurushima channel and got outlet power of 3kW at the maximum (1983-`88). There are few coasts which have sufficient tide range in Japan, but there are so good many applicable coasts in China and Southeast Asia that the tidal power generation is to be expectatively. 12 refs., 5 figs., 1 tab.

  6. Power conversion and quality of the Santa Clara 2 MW direct carbonate fuel cell demonstration plant

    Energy Technology Data Exchange (ETDEWEB)

    Skok, A.J. [Fuel Cell Engineering Corp., Danbury, CT (United States); Abueg, R.Z. [Basic Measuring Instruments, Santa Clara, CA (United States); Schwartz, P. [Fluor Daniel, Inc., Irvine, CA (United States)] [and others

    1996-12-31

    The Santa Clara Demonstration Project (SCDP) is the first application of a commercial-scale carbonate fuel cell power plant on a US electric utility system. It is also the largest fuel cell power plant ever operated in the United States. The 2MW plant, located in Santa Clara, California, utilizes carbonate fuel cell technology developed by Energy Research Corporation (ERC) of Danbury, Connecticut. The ultimate goal of a fuel cell power plant is to deliver usable power into an electrical distribution system. The power conversion sub-system does this for the Santa Clara Demonstration Plant. A description of this sub-system and its capabilities follows. The sub-system has demonstrated the capability to deliver real power, reactive power and to absorb reactive power on a utility grid. The sub-system can be operated in the same manner as a conventional rotating generator except with enhanced capabilities for reactive power. Measurements demonstrated the power quality from the plant in various operating modes was high quality utility grade power.

  7. ASTRID power conversion system: Assessment on steam and gas options

    International Nuclear Information System (INIS)

    Laffont, Guy; Cachon, Lionel; Jourdain, Vincent; Fauque, Jean Marie

    2013-01-01

    Conclusion: ◆ Two power conversion systems have been investigated for the ASTRID prototype. ◆ Steam PCS: • Most mature system based on a well-developed turbomachinery technology. • High plant efficiency. • Studies on steam generators designs and leak detection systems in progress with the aim of reducing the risk of large SWRs and of limiting its consequences. • Design and licensing safety assessment of a SFR must deal with the Sodium Water Air reaction (SWAR). ◆ Gas PCS: • Strong advantage as it inherently eliminates the SWR and SWAR risks. • Very innovative option: major breakthroughs but feasibility and viability not yet demonstrated. • Remaining technological challenges but no showstopper indentified. • General architecture: investigations in progress to improve performances, operability and maintainability

  8. Hierarchically structured carbon nanotubes for energy conversion and storage

    Science.gov (United States)

    Du, Feng

    As the world population continues to increase, large amounts of energy are consumed. Reality pushes us to find new energy or use our current energy more efficiently. Researches on energy conversion and storage have become increasingly important and essential. This grand challenge research has led to a recent focus on nanostructured materials. Carbon nanomaterials such as carbon nanotubes (CNTs) play a critical role in all of these nanotechnology challenges. CNTs have a very large surface area, a high electrochemical accessibility, high electronic conductivity and strong mechanical properties. This combination of properties makes them promising materials for energy device applications, such as FETs, supercapacitors, fuel cells, and lithium batteries. This study focuses on exploring the possibility of using vertically aligned carbon nanotubes (VA-CNTs) as the electrode materials in these energy applications. For the application of electrode materials, electrical conductive, vertically aligned CNTs with controllable length and diameter were synthesized. Several CVD methods for VA-CNT growth have been explored, although the iron / aluminum pre-coated catalyst CVD system was the main focus. A systematic study of several factors, including growth time, temperature, gas ratio, catalyst coating was conducted. The mechanism of VA-CNTs was discussed and a model for VA-CNT length / time was proposed to explain the CNT growth rate. Furthermore, the preferential growth of semiconducting (up to 96 atom% carbon) VA-SWNTs by using a plasma enhanced CVD process combined with fast heating was also explored, and these semiconducting materials have been directly used for making FETs using simple dispersion in organic solvent, without any separation and purification. Also, by inserting electron-accepting nitrogen atoms into the conjugated VA-CNT structure during the growth process, we synthesized vertically aligned nitrogen containing carbon nanotubes (VA-NCNTs). After purification of

  9. 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.

  10. Distributed energy systems with wind power and energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Korpaas, Magnus

    2004-07-01

    The topic of this thesis is the study of energy storage systems operating with wind power plants. The motivation for applying energy storage in this context is that wind power generation is intermittent and generally difficult to predict, and that good wind energy resources are often found in areas with limited grid capacity. Moreover, energy storage in the form of hydrogen makes it possible to provide clean fuel for transportation. The aim of this work has been to evaluate how local energy storage systems should be designed and operated in order to increase the penetration and value of wind power in the power system. Optimization models and sequential and probabilistic simulation models have been developed for this purpose. Chapter 3 presents a sequential simulation model of a general wind hydrogen energy system. Electrolytic hydrogen is used either as a fuel for transportation or for power generation in a stationary fuel cell. The model is useful for evaluating how hydrogen storage can increase the penetration of wind power in areas with limited or no transmission capacity to the main grid. The simulation model is combined with a cost model in order to study how component sizing and choice of operation strategy influence the performance and economics of the wind-hydrogen system. If the stored hydrogen is not used as a separate product, but merely as electrical energy storage, it should be evaluated against other and more energy efficient storage options such as pumped hydro and redox flow cells. A probabilistic model of a grid-connected wind power plant with a general energy storage unit is presented in chapter 4. The energy storage unit is applied for smoothing wind power fluctuations by providing a firm power output to the grid over a specific period. The method described in the chapter is based on the statistical properties of the wind speed and a general representation of the wind energy conversion system and the energy storage unit. This method allows us to

  11. Pyroelectric and dielectric energy conversion – A new view of the old problem

    International Nuclear Information System (INIS)

    Poprawski, W.; Gnutek, Z.; Radojewski, J.; Poprawski, R.

    2015-01-01

    The pyroelectric effect is commonly used to construct infrared radiation detectors. In this article we intend to pay attention to a possibility of the pyroelectric effect employment along with the temperature dependence of the dielectric permittivity into a direct conversion of the time-alternating heat flux and the electromagnetic radiation to the electric energy. Converters making use of the mentioned phenomena can be applied in the low-power electric energy generators mounted in autonomous electronic devices. Operation principles for pyroelectric and dielectric generators (PEG and DEG) of the electric energy are presented in this work together with a brief review on ferro- and antiferroelectric materials suitable for the generators. It was shown that for the ferroelectrics with the second-order phase transition the conversion efficiency of PEGs did not depend on temperature in a wide temperature range, and ferroelectrics showing an order–disorder phase transition together with composites and heterostructures based on these ferroelectrics had high conversion efficiency. For the first time ferro- and antiferroelectric materials were extensively reviewed with regard to their applicability in PEGs. It was also shown that ferro- and antiferroelectrics with translation-type phase transition, quantum ferroelectrics, ferro- and antiferroelectric relaxors were good materials for DEGs. Considering literature data the efficiency for the thermal-to-electrical energy conversion was estimated for a few typical material groups. Advantages and disadvantages of the individual groups were presented along with their possible limitations for PEG and DEG usage. - Highlights: • A direct conversion of the alternating heat flux to the electric energy is described. • Order–disorder-type ferroelectrics were found to be suitable for pyroelectric energy generators. • Certain ferro- and antiferroelectrics, quantum ones and relaxors were good for dielectric converters. • The

  12. High Temperature Fusion Reactor Cooling Using Brayton Cycle Based Partial Energy Conversion

    Science.gov (United States)

    Juhasz, Albert J.; Sawicki, Jerzy T.

    2003-01-01

    For some future space power systems using high temperature nuclear heat sources most of the output energy will be used in other than electrical form, and only a fraction of the total thermal energy generated will need to be converted to electrical work. The paper describes the conceptual design of such a partial energy conversion system, consisting of a high temperature fusion reactor operating in series with a high temperature radiator and in parallel with dual closed cycle gas turbine (CCGT) power systems, also referred to as closed Brayton cycle (CBC) systems, which are supplied with a fraction of the reactor thermal energy for conversion to electric power. Most of the fusion reactor's output is in the form of charged plasma which is expanded through a magnetic nozzle of the interplanetary propulsion system. Reactor heat energy is ducted to the high temperature series radiator utilizing the electric power generated to drive a helium gas circulation fan. In addition to discussing the thermodynamic aspects of the system design the authors include a brief overview of the gas turbine and fan rotor-dynamics and proposed bearing support technology along with performance characteristics of the three phase AC electric power generator and fan drive motor.

  13. The 20 year evolution of an energy conversion course at the United States Military Academy

    International Nuclear Information System (INIS)

    Bailey, Margaret; Oezer Arnas, A.; Potter, Robert; Samples, Jerry W.

    2004-01-01

    Over the past several years, an energy conversion course offered by the Mechanical Engineering Program at the United States Military Academy in West Point, New York, has evolved into a cohesive series of lessons addressing three general topical areas: advanced thermodynamics, advanced mechanical system analysis, and direct energy conversion systems. Mechanical engineering majors enroll in Energy Conversion Systems (ME 472) during the fall semester of their senior year as an advanced elective. ME 472 builds directly on the material covered in Thermodynamics (EM 301) taken during the student's junior year. In the first segment of ME 472, the students study advanced thermodynamic topics including exergy and combustion analyses. The students then analyze various mechanical systems including refrigeration systems, internal combustion engines, boilers, and fossil fuel fired steam and gas turbine combined power plants. Exergetic efficiencies of various equipment and systems are determined. The final portion of the course covers direct energy conversion technology, including fuel cells, photovoltaics, thermoelectricity, thermionics and magnetohydrodynamics. Supplemental lessons on energy storage, semi-conductors and nonreactive energy sources (such as solar collectors, wind turbines, and hydroelectric plants) are included here. This paper discusses the evolution of ME 472 since its inception and explains the motivations for the course's progress

  14. Electrohydrodynamics: a high-voltage direct energy conversion process; L'electrohydrodynamique: Un procede de conversion directe d'energie a haute tension

    Energy Technology Data Exchange (ETDEWEB)

    Brun, S [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1967-04-15

    This analysis consists of a theoretical and practical study of a high-tension electrical power generator based on the Van de Graaff generator principle, the main difference being that the charges produced are transported by a gas in motion and not by a belt. The electrical and thermal properties of such a generator are studied, as well as the difficult problem of the production of the ionised particles used in the conversion. A certain number of results already published on this process for converting kinetic energy into electrical energy is given, as well as some possible applications in the field of space technology. (author) [French] Cette analyse est une etude theorique et pratique d'un generateur de puissance electrique a haute tension, base sur le principe du generateur Van de Graaff, la difference principale etant que les charges produites sont transportees pur un gaz en mouvement et non par une courroie. Les proprietes electriques et thermiques d'un tel generateur sont etudiees ainsi que le probleme delicat de la production des particules ionisees utilisees dans la conversion. Un certain nombre de resultats publies sur ce procede de conversion d'energie cinetique en energie electrique sont reproduits, ainsi que les applications possibles aux problemes spatiaux. (auteur)

  15. Closed Brayton cycle power conversion systems for nuclear reactors :

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Steven A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lipinski, Ronald J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vernon, Milton E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sanchez, Travis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2006-04-01

    This report describes the results of a Sandia National Laboratories internally funded research program to study the coupling of nuclear reactors to gas dynamic Brayton power conversion systems. The research focused on developing integrated dynamic system models, fabricating a 10-30 kWe closed loop Brayton cycle, and validating these models by operating the Brayton test-loop. The work tasks were performed in three major areas. First, the system equations and dynamic models for reactors and Closed Brayton Cycle (CBC) systems were developed and implemented in SIMULINKTM. Within this effort, both steady state and dynamic system models for all the components (turbines, compressors, reactors, ducting, alternators, heat exchangers, and space based radiators) were developed and assembled into complete systems for gas cooled reactors, liquid metal reactors, and electrically heated simulators. Various control modules that use proportional-integral-differential (PID) feedback loops for the reactor and the power-conversion shaft speed were also developed and implemented. The simulation code is called RPCSIM (Reactor Power and Control Simulator). In the second task an open cycle commercially available Capstone C30 micro-turbine power generator was modified to provide a small inexpensive closed Brayton cycle test loop called the Sandia Brayton test-Loop (SBL-30). The Capstone gas-turbine unit housing was modified to permit the attachment of an electrical heater and a water cooled chiller to form a closed loop. The Capstone turbine, compressor, and alternator were used without modification. The Capstone systems nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system also were reused. The rotational speed of the turbo-machinery is controlled by adjusting the alternator load by using the electrical grid as the load bank. The SBL-30 test loop was operated at

  16. Power Management for Energy Systems

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel

    In this thesis, we consider the control of two different industrial applications that belong at either end of the electricity grid; a power consumer in the form of a commercial refrigeration system, and wind turbines for power production. Our primary studies deal with economic model predictive...... penetration of renewable, fossil-free energy sources such as solar and wind power. To facilitate such intermittent power producers, we must not only control the production of electricity, but also the consumption, in an ecient and exible manner. By enabling the use of thermal energy storage in supermarkets...... of temperature dependent efficiencies in the refrigeration cycle. -Nonlinear economic MPC with uncertain predictions and the implementation of very simple predictors that use entirely historical data of, e.g., electricity prices and outdoor temperatures. Economic MPC for wind turbines, including -Optimal steady...

  17. Feasibility study for the partial conversion of a hydropower plant into a pumped-storage power plant: a case study of hydroelectric power plant La Barca (Asturias, Spain

    Directory of Open Access Journals (Sweden)

    E. Antuña Yudego

    2017-01-01

    Full Text Available Renewable energy sources have reported an unprecedented increase of global installed renewable power capacity. Against the advantages provided by this renewable power generation technology it should be taken into account an important issue: these intermittent energy sources supply a fluctuating output which is difficult to manage. Pumped-storage hydro power plants reappear in these circumstances as an efficient form of energy storage which allows to use reserves when necessary, enabling power generation output to cover continuously this energy demand. The present paper shows a simplified feasibility study of the partial conversion of hydropower plant La Barca, in Asturias, into a reversible storage through the development of an algorithm to simulate its operation according to electricity market prices. For this purpose, the operation in the deviation management market is considered and the technical modifications required for the conversion are shown. The estimation of costs and incomes present a feasible scenario.

  18. Thermodynamic limits to the conversion of blackbody radiation by quantum systems. [with application to solar energy conversion devices

    Science.gov (United States)

    Buoncristiani, A. M.; Smith, B. T.; Byvik, C. E.

    1982-01-01

    Using general thermodynamic arguments, we analyze the conversion of the energy contained in the radiation from a blackbody to useful work by a quantum system. We show that the energy available for conversion is bounded above by the change in free energy in the incident and reradiated fields and that this free energy change depends upon the temperature of the receiving device. Universal efficiency curves giving the ultimate thermodynamic conversion efficiency of the quantum system are presented in terms of the blackbody temperature and the temperature and threshold energy of the quantum system. Application of these results is made to a variety of systems including biological photosynthetic, photovoltaic, and photoelectrochemical systems.

  19. Brayton Power Conversion Unit Tested: Provides a Path to Future High-Power Electric Propulsion Missions

    Science.gov (United States)

    Mason, Lee S.

    2003-01-01

    Closed-Brayton-cycle conversion technology has been identified as an excellent candidate for nuclear electric propulsion (NEP) power conversion systems. Advantages include high efficiency, long life, and high power density for power levels from about 10 kWe to 1 MWe, and beyond. An additional benefit for Brayton is the potential for the alternator to deliver very high voltage as required by the electric thrusters, minimizing the mass and power losses associated with the power management and distribution (PMAD). To accelerate Brayton technology development for NEP, the NASA Glenn Research Center is developing a low-power NEP power systems testbed that utilizes an existing 2- kWe Brayton power conversion unit (PCU) from previous solar dynamic technology efforts. The PCU includes a turboalternator, a recuperator, and a gas cooler connected by gas ducts. The rotating assembly is supported by gas foil bearings and consists of a turbine, a compressor, a thrust rotor, and an alternator on a single shaft. The alternator produces alternating-current power that is rectified to 120-V direct-current power by the PMAD unit. The NEP power systems testbed will be utilized to conduct future investigations of operational control methods, high-voltage PMAD, electric thruster interactions, and advanced heat rejection techniques. The PCU was tested in Glenn s Vacuum Facility 6. The Brayton PCU was modified from its original solar dynamic configuration by the removal of the heat receiver and retrofitting of the electrical resistance gas heater to simulate the thermal input of a steady-state nuclear source. Then, the Brayton PCU was installed in the 3-m test port of Vacuum Facility 6, as shown. A series of tests were performed between June and August of 2002 that resulted in a total PCU operational time of about 24 hr. An initial test sequence on June 17 determined that the reconfigured unit was fully operational. Ensuing tests provided the operational data needed to characterize PCU

  20. Advanced materials and coatings for energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    St Pierre, George R. [Ohio State Univ., Materials Science and Engineering Dept., Columbus, OH (United States)

    1997-12-31

    Following an historical review of the development of high-temperature alloys for energy conversion systems including turbine engines, some of the current advances in single crystal materials, intermetallics, metal-matrix composites, and ceramic-matrix composites are discussed. Particular attention is directed at creep phenomena, fatigue properties and oxidation resistance. Included within the discussions is the current status of carbon/carbon composites as potential high-temperature engineering materials and the development of coating systems for thermal barrier and oxidation protection. The specific influences of combustion gas compositions, i.e., oxidation potential, sulfur, halides, etc. are discussed. A current list of eligible advanced materials and coatings systems is presented and assessed. Finally, the critical failure mechanism and life-prediction parameters for some of the new classes of advanced structural materials are elaborated with the view to achieving affordability and extended life with a high degree of reliability. Examples are drawn from a variety of energy conversion systems. (Author)