WorldWideScience

Sample records for thermal energy conversion

  1. 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.

  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. 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

  4. 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.

  5. 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%

  6. Implosive Thermal Plasma Source for Energy Conversion

    Czech Academy of Sciences Publication Activity Database

    Šonský, Jiří; Tesař, Václav; Gruber, Jan; Mašláni, Alan

    2017-01-01

    Roč. 4, č. 1 (2017), s. 87-90 ISSN 2336-2626 Institutional support: RVO:61388998 ; RVO:61389021 Keywords : implosion * thermal plasma * detonation wave Subject RIV: BL - Plasma and Gas Discharge Physics; BL - Plasma and Gas Discharge Physics (UFP-V) OBOR OECD: Fluids and plasma physics (including surface physics); Fluids and plasma physics (including surface physics) (UFP-V) https://ppt.fel.cvut.cz/ppt2017.html#number1

  7. 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.…

  8. Ocean Thermal Energy Conversion (OTEC) program. FY 1977 program summary

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-01-01

    An overview is given of the ongoing research, development, and demonstration efforts. Each of the DOE's Ocean Thermal Energy Conversion projects funded during fiscal year 1977 (October 1, 1976 through September 30, 1977) is described and each project's status as of December 31, 1977 is reflected. These projects are grouped as follows: program support, definition planning, engineering development, engineering test and evaluation, and advanced research and technology. (MHR)

  9. Solar-thermal conversion and thermal energy storage of graphene foam-based composite

    KAUST Repository

    Zhang, Lianbin

    2016-07-11

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.

  10. Solar-thermal conversion and thermal energy storage of graphene foam-based composites.

    Science.gov (United States)

    Zhang, Lianbin; Li, Renyuan; Tang, Bo; Wang, Peng

    2016-08-14

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances the heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.

  11. 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.

  12. Novel Magnetic-to-Thermal Conversion and Thermal Energy Management Composite Phase Change Material

    Directory of Open Access Journals (Sweden)

    Xiaoqiao Fan

    2018-05-01

    Full Text Available Superparamagnetic materials have elicited increasing interest due to their high-efficiency magnetothermal conversion. However, it is difficult to effectively manage the magnetothermal energy due to the continuous magnetothermal effect at present. In this study, we designed and synthesized a novel Fe3O4/PEG/SiO2 composite phase change material (PCM that can simultaneously realize magnetic-to-thermal conversion and thermal energy management because of outstanding thermal energy storage ability of PCM. The composite was fabricated by in situ doping of superparamagnetic Fe3O4 nanoclusters through a simple sol–gel method. The synthesized Fe3O4/PEG/SiO2 PCM exhibited good thermal stability, high phase change enthalpy, and excellent shape-stabilized property. This study provides an additional promising route for application of the magnetothermal effect.

  13. 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.

  14. Conversion of concentrated solar thermal energy into chemical energy.

    Science.gov (United States)

    Tamaura, Yutaka

    2012-01-01

    When a concentrated solar beam is irradiated to the ceramics such as Ni-ferrite, the high-energy flux in the range of 1500-2500 kW/m(2) is absorbed by an excess Frenkel defect formation. This non-equilibrium state defect is generated not by heating at a low heating-rate (30 K/min), but by irradiating high flux energy of concentrated solar beam rapidly at a high heating rate (200 K/min). The defect can be spontaneously converted to chemical energy of a cation-excess spinel structure (reduced-oxide form) at the temperature around 1773 K. Thus, the O(2) releasing reaction (α-O(2) releasing reaction) proceeds in two-steps; (1) high flux energy of concentrated solar beam absorption by formation of the non-equilibrium Frenkel defect and (2) the O(2) gas formation from the O(2-) in the Frenkel defect even in air atmosphere. The 2nd step proceeds without the solar radiation. We may say that the 1st step is light reaction, and 2nd step, dark reaction, just like in photosynthesis process.

  15. Ocean Thermal Energy Conversion (OTEC) Programmatic Environmental Analysis--Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Authors, Various

    1980-01-01

    The programmatic environmental analysis is an initial assessment of Ocean Thermal Energy Conversion (OTEC) technology considering development, demonstration and commercialization. It is concluded that the OTEC development program should continue because the development, demonstration, and commercialization on a single-plant deployment basis should not present significant environmental impacts. However, several areas within the OTEC program require further investigation in order to assess the potential for environmental impacts from OTEC operation, particularly in large-scale deployments and in defining alternatives to closed-cycle biofouling control: (1) Larger-scale deployments of OTEC clusters or parks require further investigations in order to assess optimal platform siting distances necessary to minimize adverse environmental impacts. (2) The deployment and operation of the preoperational platform (OTEC-1) and future demonstration platforms must be carefully monitored to refine environmental assessment predictions, and to provide design modifications which may mitigate or reduce environmental impacts for larger-scale operations. These platforms will provide a valuable opportunity to fully evaluate the intake and discharge configurations, biofouling control methods, and both short-term and long-term environmental effects associated with platform operations. (3) Successful development of OTEC technology to use the maximal resource capabilities and to minimize environmental effects will require a concerted environmental management program, encompassing many different disciplines and environmental specialties. This volume contains these appendices: Appendix A -- Deployment Scenario; Appendix B -- OTEC Regional Characterization; and Appendix C -- Impact and Related Calculations.

  16. Draft environmental assessment: Ocean Thermal Energy Conversion (OTEC) Pilot Plants

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, S.M.; Sands, M.D.; Donat, J.R.; Jepsen, P.; Smookler, M.; Villa, J.F.

    1981-02-01

    This Environmental Assessment (EA) has been prepared, in accordance with the National Environmental Policy Act of 1969, for the deployment and operation of a commercial 40-Megawatt (MW) Ocean Thermal Energy Conversion (OTEC) Pilot Plant (hereafter called the Pilot Plant). A description of the proposed action is presented, and a generic environment typical of the candidate Pilot Plant siting regions is described. An assessment of the potential environmental impacts associated with the proposed action is given, and the risk of credible accidents and mitigating measures to reduce these risks are considered. The Federal and State plans and policies the proposed action will encompass are described. Alternatives to the proposed action are presented. Appendix A presents the navigation and environmental information contained in the US Coast Pilot for each of the candidate sites; Appendix B provides a brief description of the methods and calculations used in the EA. It is concluded that environmental disturbances associated with Pilot Plant activities could potentially cause significant environmental impacts; however, the magnitude of these potential impacts cannot presently be assessed, due to insufficient engineering and environmental information. A site- and design-specific OTEC Pilot Plant Environmental Impact Statement (EIS) is required to resolve the potentially significant environmental effects associated with Pilot Plant deployment and operation. (WHK)

  17. Thermal to Electric Energy Conversion for Cyclic Heat Loads

    Science.gov (United States)

    Whitehead, Benjamin E.

    Today, we find cyclic heat loads almost everywhere. When we drive our cars, the engines heat up while we are driving and cool while parked. Processors heat while the computer is in use at the office and cool when idle at night. The sun heats the earth during the day and the earth radiates that heat into space at night. With modern technology, we have access to a number of methods to take that heat and convert it into electricity, but, before selecting one, we need to identify the parameters that inform decision making. The majority of the parameters for most systems include duty cycle, total cost, weight, size, thermal efficiency, and electrical efficiency. However, the importance of each of these will depend on the application. Size and weight take priority in a handheld device, while efficiency dominates in a power plant, and duty cycle is likely to dominate in highly demanding heat pump applications. Over the past decade, developments in semiconductor technology has led to the creation of the thermoelectric generator. With no moving parts and a nearly endlessly scalable nature, these generators present interesting opportunities for taking advantage of any source of waste heat. However, these generators are typically only capable of 5-8% efficiency from conversion of thermal to electric energy. [1]. Similarly, advancements in photovoltaic cells has led to the development of thermophotovoltaics. By heating an emitter to a temperature so it radiates light, a thermophotovoltaic cell then converts that light into electricity. By selecting materials that emit light in the optimal ranges of the appropriate photovoltaic cells, thermophotovoltaic systems can potentially exceed the current maximum of 10% efficiency. [2]. By pressurizing certain metal powders with hydrogen, hydrogen can be bound to the metal, creating a metal hydride, from which hydrogen can be later re-extracted under the correct pressure and temperature conditions. Since this hydriding reaction is

  18. Information-to-free-energy conversion: Utilizing thermal fluctuations.

    Science.gov (United States)

    Toyabe, Shoichi; Muneyuki, Eiro

    2013-01-01

    Maxwell's demon is a hypothetical creature that can convert information to free energy. A debate that has lasted for more than 100 years has revealed that the demon's operation does not contradict the laws of thermodynamics; hence, the demon can be realized physically. We briefly review the first experimental demonstration of Maxwell's demon of Szilard's engine type that converts information to free energy. We pump heat from an isothermal environment by using the information about the thermal fluctuations of a Brownian particle and increase the particle's free energy.

  19. 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.

  20. Iron Oxide Films Prepared by Rapid Thermal Processing for Solar Energy Conversion

    DEFF Research Database (Denmark)

    Wickman, B.; da Silva Fanta, Alice Bastos; Burrows, Andrew

    2017-01-01

    Hematite is a promising and extensively investigated material for various photoelectrochemical (PEC) processes for energy conversion and storage, in particular for oxidation reactions. Thermal treatments during synthesis of hematite are found to affect the performance of hematite electrodes...

  1. 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

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

    Science.gov (United States)

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

    1992-01-01

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

  3. Experimental Study on Conversion of Stored Thermal Energy to Mechanical Work in FCI

    International Nuclear Information System (INIS)

    Fujii-e, Y.; Kondo, S.; Mivazaki, K.

    1976-01-01

    In the present study the process how the thermal energy stored in the coolant should be converted into the mechanical work is emphasized as well as the generation of pressure waves, eliminating the complicated problems involved in FCI, such as fragmentation, heat transfer from molten fuel to coolant, etc. A simulation experiment has been performed in a small scale vertical channel using stagnant potassium. Large superheat inherent in liquid metals was utilized as the method to accumulate the thermal energy. The following experimental parameters were chosen to examine their effects on the energy conversion ratio: the heat flux, the cover gas pressure, the liquid column length, the temperature of the upper unheated region and the incipient boiling superheat (corresponding to the stored thermal energy). The results are summarized that the conversion ratio from thermal to kinetic energies has increasing trends with increases of the incipient boiling superheat, the cover gas pressure and the temperature of upper unheated region, ranging over 0.02-0.75% in the present experiment. The important conclusions of the present experiment are summarized as follows. The thermal to kinetic energy conversion ratio n k ranges over 0.02-0.75 % for ΔT s = 10-150 deg.C, estimating from the maximum velocity measured. The thermal to mechanical work conversion ratio n w ranges over 0.14-5.6%. The effect of the heat flux on the both conversion ratios is small within the range covered by the present experiment (g≤133 W/cm 2 ). The effect of the liquid column length is not presented. The thermal to kinetic energy conversion ratio increases with the incipient boiling superheat which corresponds to the stored thermal energy in the present experiment. The both conversion ratio decrease with a decrease of the cover gas pressure. This is attributable to the thermal contact in the upper unheated region. The both conversion ratios increase with an increase in the temperature of the upper

  4. Integrated photovoltaic-thermal solar energy conversion systems

    Science.gov (United States)

    Samara, G. A.

    1975-01-01

    A combined photovoltaic/thermal collector has been built and is now being tested. Initial tests have concentrated on evaluating the thermal efficiency of the collector before and after the silicon cells are mounted. With likely improvements in bonding between cells and receiver and in the absorptivity of the cells, thermal efficiencies greater than 50% can be expected for the combined receiver operating at 100 C.

  5. The conversion of the thermal energy of plasma in the SOL of tokamaks

    International Nuclear Information System (INIS)

    Nedospasov, A.V.; Nenova, N.V.

    2008-01-01

    When the plasma expands across the confining magnetic field, a part of its thermal energy is converted to electrical energy. In the SOL of tokamaks, the motion of the plasma across the field due to turbulent processes is accompanied by its departure along the open lines of the magnetic field. The conversion of thermal energy is taken into account in theoretical studies devoted to the physics of plasma in the SOL; however, this conversion is ignored in numerical models, for example, in B2-SOLPS4.0. This paper deals with thermal-to-electrical energy conversion in the SOL of tokamaks. It is demonstrated that the part of the thermal energy subjected to conversion to electrical energy forms an appreciable part of the total energy flowing in the SOL. In ITER, this fraction may be as high as 20-25%. The electrical energy generated in the SOL volume is liberated in the form of Joule heat in a relatively cold plasma in the vicinity of diverter plates or directly on these plates. (letter)

  6. Hierarchical Graphene Foam for Efficient Omnidirectional Solar-Thermal Energy Conversion.

    Science.gov (United States)

    Ren, Huaying; Tang, Miao; Guan, Baolu; Wang, Kexin; Yang, Jiawei; Wang, Feifan; Wang, Mingzhan; Shan, Jingyuan; Chen, Zhaolong; Wei, Di; Peng, Hailin; Liu, Zhongfan

    2017-10-01

    Efficient solar-thermal energy conversion is essential for the harvesting and transformation of abundant solar energy, leading to the exploration and design of efficient solar-thermal materials. Carbon-based materials, especially graphene, have the advantages of broadband absorption and excellent photothermal properties, and hold promise for solar-thermal energy conversion. However, to date, graphene-based solar-thermal materials with superior omnidirectional light harvesting performances remain elusive. Herein, hierarchical graphene foam (h-G foam) with continuous porosity grown via plasma-enhanced chemical vapor deposition is reported, showing dramatic enhancement of broadband and omnidirectional absorption of sunlight, which thereby can enable a considerable elevation of temperature. Used as a heating material, the external solar-thermal energy conversion efficiency of the h-G foam impressively reaches up to ≈93.4%, and the solar-vapor conversion efficiency exceeds 90% for seawater desalination with high endurance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Open cycle ocean thermal energy conversion system structure

    Science.gov (United States)

    Wittig, J. Michael

    1980-01-01

    A generally mushroom-shaped, open cycle OTEC system and distilled water producer which has a skirt-conduit structure extending from the enlarged portion of the mushroom to the ocean. The enlarged part of the mushroom houses a toroidal casing flash evaporator which produces steam which expands through a vertical rotor turbine, partially situated in the center of the blossom portion and partially situated in the mushroom's stem portion. Upon expansion through the turbine, the motive steam enters a shell and tube condenser annularly disposed about the rotor axis and axially situated beneath the turbine in the stem portion. Relatively warm ocean water is circulated up through the radially outer skirt-conduit structure entering the evaporator through a radially outer portion thereof, flashing a portion thereof into motive steam, and draining the unflashed portion from the evaporator through a radially inner skirt-conduit structure. Relatively cold cooling water enters the annular condenser through the radially inner edge and travels radially outwardly into a channel situated along the radially outer edge of the condenser. The channel is also included in the radially inner skirt-conduit structure. The cooling water is segregated from the potable, motive steam condensate which can be used for human consumption or other processes requiring high purity water. The expansion energy of the motive steam is partially converted into rotational mechanical energy of the turbine rotor when the steam is expanded through the shaft attached blades. Such mechanical energy drives a generator also included in the enlarged mushroom portion for producing electrical energy. Such power generation equipment arrangement provides a compact power system from which additional benefits may be obtained by fabricating the enclosing equipment, housings and component casings from low density materials, such as prestressed concrete, to permit those casings and housings to also function as a floating

  8. Conversion of thermall energy to mechanical work in the oscillations with steam condensation in pool water

    International Nuclear Information System (INIS)

    Aya, Izuo; Nariai, Hideki.

    1988-01-01

    Pressure and fluid oscillations with steam injection into pool water were discussed from the view point of the conversion of thermal energy into mechanical work. When the change of fluid state moves clockwise in the p-V diagram, the oscillation sustains since the thermal energy changes into positive work. The equations difining the mechanical work at the condensation oscillations were presented. The oscillation threshold determined by the condition that mechanical work became zero, coincided with the values derived by the linear oscillation theory. The changes of pressure and specific volume during chugging were also shown with one dimensional simulation analysis. The p-V diagrams at various chugging modes were presented with the movement of steam water interface, and the conversion efficiency of thermal energy to mechanical work was also discussed. (author)

  9. 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.

  10. Fundamental kinetics and innovative applications of nonequilibrium atomic vibration in thermal energy transport and conversion

    Science.gov (United States)

    Shin, Seungha

    All energy conversion inefficiencies begin with emission of resonant atomic motions, e.g., vibrations, and are declared as waste heat once these motions thermalize to equilibrium. The nonequilibrium energy occupancy of the vibrational modes can be targeted as a harvestable, low entropy energy source for direct conversion to electric energy. Since the lifetime of these resonant vibrations is short, special nanostructures are required with the appropriate tuning of the kinetics. These in turn require multiscale, multiphysics treatments. Atomic vibration is described with quasiparticle phonon in solid, and the optical phonon emission is dominant relaxation channel in semiconductors. These optical modes become over-occupied when their emission rate becomes larger than their decay rate, thus hindering energy relaxation and transport in devices. Effective removal of these phonons by drifting electrons is investigated by manipulating the electron distribution to have higher population in the low-energy states, thus allowing favorable phonon absorption. This is done through introduction, design and analysis of a heterobarrier conducting current, where the band gap is controlled by alloying, thus creating a spatial variation which is abrupt followed by a linear gradient (to ensure directed current). Self-consistent ensemble Monte Carlo simulations based on interaction kinetics between electron and phonon show that up to 19% of the phonon energy is converted to electric potential with an optimized GaAs/AlxGa1-xAs barrier structure over a range of current and electron densities, and this system is also verified through statistical entropy analysis. This direct energy conversion improves the device performance with lower operation temperature and enhances overall energy conversion efficiency. Through this study, the paradigm for harvesting the resonant atomic vibration is proposed, reversing the general role of phonon as only causing electric potential drop. Fundamentals

  11. Acceleration of the solar-thermal energy development but still some brakes upon photovoltaic conversion

    International Nuclear Information System (INIS)

    Anon.

    2006-01-01

    France shows today the highest growth rate for solar thermal energy with respect to other European countries. This market is structuring and tries to favour quality. A label for systems certification has been presented in January 2007. Photovoltaic conversion has been tied up for a long time by poorly attractive power repurchase tariffs. It benefits now from a propitious framework for its development even if some financial incentive questions relative to the integration of solar panels to buildings remain unanswered. (J.S.)

  12. High thermal efficiency x-ray energy conversion scheme for advanced fusion reactors

    International Nuclear Information System (INIS)

    Quimby, D.C.; Taussig, R.T.; Hertzberg, A.

    1977-01-01

    This paper reports on a new radiation energy conversion scheme which appears to be capable of producing electricity from the high quality x-ray energy with efficiencies of 60 to 70 percent. This new reactor concept incorporates a novel x-ray radiation boiler and a new thermal conversion device known as an energy exchanger. The low-Z first walls of the radiation boiler are semi-transparent to x-rays, and are kept cool by incoming working fluid, which is subsequently heated to temperatures of 2000 to 3000 0 K in the interior of the boiler by volumetric x-ray absorption. The radiation boiler may be a compact part of the reactor shell since x-rays are readily absorbed in high-Z materials. The energy exchanger transfers the high-temperature working fluid energy to a lower temperature gas which drives a conventional turbine. The overall efficiency of the cycle is characterized by the high temperature of the working fluid. The high thermal efficiencies which appear achievable with this cycle would make an otherwise marginal advanced fusion reactor into an attractive net power producer. The operating principles, initial conceptual design, and engineering problems of the radiation boiler and thermal cycle are presented

  13. 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.

  14. Research Update: Utilizing magnetization dynamics in solid-state thermal energy conversion

    Directory of Open Access Journals (Sweden)

    Stephen R. Boona

    2016-10-01

    Full Text Available We review the spin-Seebeck and magnon-electron drag effects in the context of solid-state energy conversion. These phenomena are driven by advective magnon-electron interactions. Heat flow through magnetic materials generates magnetization dynamics, which can strongly affect free electrons within or adjacent to the magnetic material, thereby producing magnetization-dependent (e.g., remnant electric fields. The relative strength of spin-dependent interactions means that magnon-driven effects can generate significantly larger thermoelectric power factors as compared to classical thermoelectric phenomena. This is a surprising situation in which spin-based effects are larger than purely charge-based effects, potentially enabling new approaches to thermal energy conversion.

  15. The kinematic Stirling engine as an energy conversion subsystem for paraboloidal dish solar thermal plants

    Science.gov (United States)

    Bowyer, J. M.

    1984-01-01

    The potential of a suitably designed and economically manufactured Stirling engine as the energy conversion subsystem of a paraboloidal dish-Stirling solar thermal power module was estimated. Results obtained by elementary cycle analyses were shown to match quite well the performance characteristics of an advanced kinematic Stirling engine, the United Stirling P-40, as established by current prototypes of the engine and by a more sophisticated analytic model of its advanced derivative. In addition to performance, brief consideration was given to other Stirling engine criteria such as durability, reliability, and serviceability. Production costs were not considered here.

  16. 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.

  17. Dynamic modeling and sensitivity analysis of solar thermal energy conversion systems

    Science.gov (United States)

    Hamilton, C. L.

    1977-01-01

    Since the energy input to solar thermal conversion systems is both time variant and probabilistic, it is unlikely that simple steady-state methods for estimating lifetime performance will provide satisfactory results. The work described here uses dynamic modeling to begin identifying what must be known about input radiation and system dynamic characteristics to estimate performance reliably. Daily operation of two conceptual solar energy systems was simulated under varying operating strategies with time-dependent radiation intensity ranging from smooth input of several magnitudes to input of constant total energy whose intensity oscillated with periods from 1/4 hour to 6 hours. Integrated daily system output and efficiency were functions of both level and dynamic characteristics of insolation. Sensitivity of output to changes in total input was greater than one.

  18. Selected legal and institutional issues related to Ocean Thermal Energy Conversion (OTEC) development

    Energy Technology Data Exchange (ETDEWEB)

    Nanda, V. P.

    1979-06-01

    Ocean Thermal Energy Conversion (OTEC), an attractive alternative to traditional energy sources, is still in the early stages of development. To facilitate OTEC commercialization, it is essential that a legal and institutional framework be designed now so as to resolve uncertainties related to OTEC development, primarily involving jurisdictional, regulatory, and environmental issues. The jurisdictional issues raised by OTEC use are dependent upon the site of an OTEC facility and its configuration; i.e., whether the plant is a semipermanent fixture located offshore or a migrating plant ship that provides a source of energy for industry at sea. These issues primarily involve the division of authority between the Federal Government and the individual coastal states. The regulatory issues raised are largely speculative: they involve the adaptation of existing mechanisms to OTEC operation. Finally, the environmental issues raised center around compliance with the National Environmental Policy Act (NEPA) as well as international agreements. 288 references.

  19. Ocean Thermal Energy Conversion Life Cycle Cost Assessment, Final Technical Report, 30 May 2012

    Energy Technology Data Exchange (ETDEWEB)

    Martel, Laura [Lockheed Martin, Manassas, VA (United States); Smith, Paul [John Halkyard and Associates: Glosten Associates, Houston, TX (United States); Rizea, Steven [Makai Ocean Engineering, Waimanalo, HI (United States); Van Ryzin, Joe [Makai Ocean Engineering, Waimanalo, HI (United States); Morgan, Charles [Planning Solutions, Inc., Vancouver, WA (United States); Noland, Gary [G. Noland and Associates, Inc., Pleasanton, CA (United States); Pavlosky, Rick [Lockheed Martin, Manassas, VA (United States); Thomas, Michael [Lockheed Martin, Manassas, VA (United States); Halkyard, John [John Halkyard and Associates: Glosten Associates, Houston, TX (United States)

    2012-05-30

    The Ocean Thermal Energy Conversion (OTEC) Life Cycle Cost Assessment (OLCCA) is a study performed by members of the Lockheed Martin (LM) OTEC Team under funding from the Department of Energy (DOE), Award No. DE-EE0002663, dated 01/01/2010. OLCCA objectives are to estimate procurement, operations and maintenance, and overhaul costs for two types of OTEC plants: -Plants moored to the sea floor where the electricity produced by the OTEC plant is directly connected to the grid ashore via a marine power cable (Grid Connected OTEC plants) -Open-ocean grazing OTEC plant-ships producing an energy carrier that is transported to designated ports (Energy Carrier OTEC plants) Costs are developed using the concept of levelized cost of energy established by DOE for use in comparing electricity costs from various generating systems. One area of system costs that had not been developed in detail prior to this analysis was the operations and sustainment (O&S) cost for both types of OTEC plants. Procurement costs, generally referred to as capital expense and O&S costs (operations and maintenance (O&M) costs plus overhaul and replacement costs), are assessed over the 30 year operational life of the plants and an annual annuity calculated to achieve a levelized cost (constant across entire plant life). Dividing this levelized cost by the average annual energy production results in a levelized cost of electricity, or LCOE, for the OTEC plants. Technical and production efficiency enhancements that could result in a lower value of the OTEC LCOE were also explored. The thermal OTEC resource for Oahu, Hawaii and projected build out plan were developed. The estimate of the OTEC resource and LCOE values for the planned OTEC systems enable this information to be displayed as energy supplied versus levelized cost of the supplied energy; this curve is referred to as an Energy Supply Curve. The Oahu Energy Supply Curve represents initial OTEC deployment starting in 2018 and demonstrates the

  20. Semiconductor-based Multilayer Selective Solar Absorber for Unconcentrated Solar Thermal Energy Conversion.

    Science.gov (United States)

    Thomas, Nathan H; Chen, Zhen; Fan, Shanhui; Minnich, Austin J

    2017-07-13

    Solar thermal energy conversion has attracted substantial renewed interest due to its applications in industrial heating, air conditioning, and electricity generation. Achieving stagnation temperatures exceeding 200 °C, pertinent to these technologies, with unconcentrated sunlight requires spectrally selective absorbers with exceptionally low emissivity in the thermal wavelength range and high visible absorptivity for the solar spectrum. In this Communication, we report a semiconductor-based multilayer selective absorber that exploits the sharp drop in optical absorption at the bandgap energy to achieve a measured absorptance of 76% at solar wavelengths and a low emittance of approximately 5% at thermal wavelengths. In field tests, we obtain a peak temperature of 225 °C, comparable to that achieved with state-of-the-art selective surfaces. With straightforward optimization to improve solar absorption, our work shows the potential for unconcentrated solar thermal systems to reach stagnation temperatures exceeding 300 °C, thereby eliminating the need for solar concentrators for mid-temperature solar applications such as supplying process heat.

  1. Iron Oxide Films Prepared by Rapid Thermal Processing for Solar Energy Conversion.

    Science.gov (United States)

    Wickman, B; Bastos Fanta, A; Burrows, A; Hellman, A; Wagner, J B; Iandolo, B

    2017-01-16

    Hematite is a promising and extensively investigated material for various photoelectrochemical (PEC) processes for energy conversion and storage, in particular for oxidation reactions. Thermal treatments during synthesis of hematite are found to affect the performance of hematite electrodes considerably. Herein, we present hematite thin films fabricated via one-step oxidation of Fe by rapid thermal processing (RTP). In particular, we investigate the effect of oxidation temperature on the PEC properties of hematite. Films prepared at 750 °C show the highest activity towards water oxidation. These films show the largest average grain size and the highest charge carrier density, as determined from electron microscopy and impedance spectroscopy analysis. We believe that the fast processing enabled by RTP makes this technique a preferred method for investigation of novel materials and architectures, potentially also on nanostructured electrodes, where retaining high surface area is crucial to maximize performance.

  2. ECO steam explosion experiments on the conversion of thermal into mechanical energy

    International Nuclear Information System (INIS)

    Cherdron, W.; Kaiser, A.; Schuetz, W.; Will, H.

    2001-01-01

    In case of a steam explosion, e.g. as a consequence of a severe reactor accident, part of the thermal energy of the melt is transferred into mechanical energy. At Forschungszentrum Karlsruhe, so-called ECO experiments, are being directed to measure the conversion factor under well-defined conditions. In ECO, alumina from a thermite reaction is used as a simulating material instead of corium. Dimensions of the test facility as well as major test conditions, e.g. temperature and release mode of the melt, water inventory and test procedure, are based on the former PREMIX experimental series. In the paper, results of the first test, ECO 01, are given. (orig.)

  3. Study of Thermally Responsive Ionic Liquids for Novel Water Desalination and Energy Conversion Applications

    KAUST Repository

    Zhong, Yujiang

    2018-04-01

    The rapidly expanding of the global population in the 21st-century forces people facing two serious problems: water scarcity and energy shortage. Enormous continuous studies focus on providing enough fresh water and energy in a sustainable way. This thesis aims at exploring novel membrane processes based on thermally responsive ionic liquids with the upper critical solution temperature (UCST ILs) for water desalination and energy conversion from low-grade heat energy to electricity. A UCST IL protonated betaine bis(trifluoromethylsulfonyl)imide ([Hbet][Tf2N]) was first experimentally studied as a novel draw solute in a thermal forward osmosis (FO). A 3.2 M [Hbet][Tf2N] solution can be obtained via spontaneous phase separation from an IL and water mixture at room temperature. By heating and maintaining the temperature above 56°C, this solution can draw water from high-salinity solution up to 3.0 M, 5 times salty as the sea water. The IL draw solution can be easily regenerated by phase separation. Conducting the FO process at higher temperatures can also increase the water flux. According to the different choices of the freshwater polishing step, the electric energy consumption in this novel process was estimated as 26.3% to 64.2% of conventional one-step sea water reverse osmosis. Two UCST ILs with better performance, [Hbet][Tf2N] and choline bis(trifluoromethylsulfonyl)imide ([Choline][Tf2N]), were selected as the agents in a novel closed-loop thermally responsive IL osmotic heat engine (TRIL-OHE) to convert low-grade thermal energy to electricity. The specific energies of the [Hbet][Tf2N] system and the [Choline][Tf2N] system are 2500 kJ/t and 3700 kJ/t, which are 2.7 and 4.0 times of the seawater and river water system, respectively. The maximum power density measured from a commercial FO membrane is 1.5 W/m2 for the [Hbet][Tf2N] system and 2.3 W/m2 for the [Choline][Tf2N] system, leaving a big room to improve if highly permeable membranes are used. Another

  4. High-frequency thermal-electrical cycles for pyroelectric energy conversion

    International Nuclear Information System (INIS)

    Bhatia, Bikram; Damodaran, Anoop R.; Cho, Hanna; Martin, Lane W.; King, William P.

    2014-01-01

    We report thermal to electrical energy conversion from a 150 nm thick BaTiO 3 film using pyroelectric cycles at 1 kHz. A microfabricated platform enables temperature and electric field control with temporal resolution near 1 μs. The rapid electric field changes as high as 11 × 10 5  kV/cm-s, and temperature change rates as high as 6 × 10 5  K/s allow exploration of pyroelectric cycles in a previously unexplored operating regime. We investigated the effect of phase difference between electric field and temperature cycles, and electric field and temperature change rates on the electrical energy generated from thermal-electrical cycles based on the pyroelectric Ericsson cycle. Complete thermodynamic cycles are possible up to the highest cycle rates tested here, and the energy density varies significantly with phase shifts between temperature and electric field waveforms. This work could facilitate the design and operation of pyroelectric cycles at high cycle rates, and aid in the design of new pyroelectric systems

  5. 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.

  6. Graphene-based photovoltaic cells for near-field thermal energy conversion.

    Science.gov (United States)

    Messina, Riccardo; Ben-Abdallah, Philippe

    2013-01-01

    Thermophotovoltaic devices are energy-conversion systems generating an electric current from the thermal photons radiated by a hot body. While their efficiency is limited in far field by the Schockley-Queisser limit, in near field the heat flux transferred to a photovoltaic cell can be largely enhanced because of the contribution of evanescent photons, in particular for a source supporting a surface mode. Unfortunately, in the infrared where these systems operate, the mismatch between the surface-mode frequency and the semiconductor gap reduces drastically the potential of this technology. In this paper we propose a modified thermophotovoltaic device in which the cell is covered by a graphene sheet. By discussing the transmission coefficient and the spectral properties of the flux, we show that both the cell efficiency and the produced current can be enhanced, paving the way to promising developments for the production of electricity from waste heat.

  7. A THERMAL-HYDRAULIC SYSTEM FOR THE CONVERSION AND THE STORAGE OF ENERGY

    Directory of Open Access Journals (Sweden)

    MITRAN Tudor

    2016-05-01

    Full Text Available The paper proposes the concept design of a thermal-hydraulic system that converts the thermal energy (from the geothermal water, from the cooling water of power equipment, from exhaust gasses, and so. in hydrostatic energy, that is stored in a hydraulic accumulator. The hydraulic energy can be converted into electrical energy when needed.

  8. 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).

  9. Solar-thermal conversion and thermal energy storage of graphene foam-based composite

    KAUST Repository

    Zhang, Lianbin; Li, Renyuan; Tang, Bo; Wang, Peng

    2016-01-01

    is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar

  10. A novel Carnot-based cycle for ocean thermal energy conversion

    International Nuclear Information System (INIS)

    Semmari, Hamza; Stitou, Driss; Mauran, Sylvain

    2012-01-01

    A thermodynamic engine cycle can be implemented by exploiting the temperature difference existing between the warm surface seawater and cold deep seawater. It employs a working fluid that evaporates by warm seawater, produces work in an expander device, such as a gas turbine and finally condenses by cold deep seawater. A new Carnot-based cycle for OTEC applications, called CAPILI cycle is presented. In this new engine cycle, work is produced by the movement of an inert liquid through a hydraulic turbine. This inert liquid characterized by a very low saturation pressure and immiscibility with the working fluid, acts as a liquid piston that moves alternately between two insulated cylinders. The insulated cylinders are connected alternately to an evaporator and a condenser, each of them operates at different pressure and temperature levels. A performance study which consists in a steady state energy balance is realised first to select the most suitable working fluid for this specific application. It was found that the best fluid is the HFC refrigerant R134a. A dynamic modelling based on the concept of equivalent Gibbs system is carried out to appreciate the dynamic behaviour and the performances of this new thermal conversion process. -- Highlights: ► A novel Carnot-based cycle operating with a liquid piston is investigated for OTEC application. ► The most suitable working fluid giving the best performances is found to be the HFC R134a. ► The performances of this new thermal process are evaluated using a dynamic modelling. ► A thermal efficiency of 1.9% can be obtained by exploiting seawater temperature difference of 20 °C. ► A net cycle efficiency of 1.2% is achieved considering a net to gross power production ratio of 61%.

  11. Evaluation of thermal efficiency and energy conversion of thermoacoustic Stirling engines

    International Nuclear Information System (INIS)

    Zhong Junhu; Zheng Yuli; Qing Li; Qiang Li

    2010-01-01

    Thermodynamic cycle transferring heat and work was executed in thermoacoustic engines, when the acoustic resonators substituted the moving mechanical components of the traditional heat engines. Based on the traveling-wave phasing and reversible heat transfer, thermoacoustic Stirling engines could achieve 70% of the Carnot efficiency theoretically, if the inevitable viscous dissipation in resonators was also counted as exported power. It should be pointed out an error on this efficiency evaluation in the previous literatures. More than 70% of the acoustic power production was often consumed by the side-branch resonator that was the essential configuration to build up a thermoacoustic Stirling engine. According to the simulation results and some experimental data, the actual available acoustic power consumed by the acoustic loads was restricted by the operating peak-to-mean pressure ratio, i.e. |p 1 /p m |. When the peak-to-mean pressure ratio operated on 4-6.5%, the thermal efficiency and power density of the available acoustic power reached higher levels. But the available acoustic power would approach zero when |p 1 /p m | attained 10%. It was approved that the turbulence oscillation occurred on the higher |p 1 /p m | (usually >4%) was the main reason of the excess dissipation in the side-branch resonator. This character of the available power limited the wide application of thermoacoustic Stirling engines. The evaluation of thermal efficiency and energy conversion also indicated the improving direction of thermoacoustic Stirling engines. Generators driven by the thermoacoustic Stirling engines were an effective way, due to the elimination of the side-branch resonator. To achieve a high power density and a high pressure ratio on the higher available power efficiency level, the standing-wave thermoacoustic engines might outvie the traveling-wave thermoacoustic engines. To enjoy the best features of standing-wave engines and traveling-wave engines simultaneously

  12. 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…

  13. Complex thermal energy conversion systems for efficient use of locally available biomass

    International Nuclear Information System (INIS)

    Kalina, Jacek

    2016-01-01

    This paper is focused on a theoretical study in search for new technological solutions in the field of electricity generation from biomass in small-scale distributed cogeneration systems. The purpose of this work is to draw readers' attention to possibilities of design complex multi-component hybrid and combined technological structures of energy conversion plants for effective use of locally available biomass resources. As an example, there is presented analysis of cogeneration system that consists of micro-turbine, high temperature fuel cell, inverted Bryton cycle module and biomass gasification island. The project assumes supporting use of natural gas and cooperation of the plant with a low-temperature district heating network. Thermodynamic parameters, energy conversion effectiveness and economic performance are examined. Results show relatively high energy conversion performance and on the other hand weak financial indices of investment projects at the current level of energy prices. It is however possible under certain conditions to define an optimistic business model that leads to a feasible project. - Highlights: • Concept of biomass energy conversion plant is proposed and theoretically analysed. • MCFC type fuel cell is fuelled with biomass gasification gas. • Natural gas fired microturbine is considered as a source of continuous power. • Inverted Bryton Cycle is considered for utilisation of high temperature exhaust gas.

  14. Hierarchically interconnected porous scaffolds for phase change materials with improved thermal conductivity and efficient solar-to-electric energy conversion.

    Science.gov (United States)

    Yang, Jie; Yu, Peng; Tang, Li-Sheng; Bao, Rui-Ying; Liu, Zheng-Ying; Yang, Ming-Bo; Yang, Wei

    2017-11-23

    An ice-templating self-assembly strategy and a vacuum impregnation method were used to fabricate polyethylene glycol (PEG)/hierarchical porous scaffold composite phase change materials (PCMs). Hierarchically interconnected porous scaffolds of boron nitride (BN), with the aid of a small amount of graphene oxide (GO), endow the composite PCMs with high thermal conductivity, excellent shape-stability and efficient solar-to-electric energy conversion. The formation of a three-dimensional (3D) thermally conductive pathway in the composites contributes to improving the thermal conductivity up to 2.36 W m -1 K -1 at a relatively low content of BN (ca. 23 wt%). This work provides a route for thermally conductive and shape-stabilized composite PCMs used as energy storage materials.

  15. 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

  16. 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.

  17. 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...

  18. A functional form-stable phase change composite with high efficiency electro-to-thermal energy conversion

    International Nuclear Information System (INIS)

    Wu, Wenhao; Huang, Xinyu; Li, Kai; Yao, Ruimin; Chen, Renjie; Zou, Ruqiang

    2017-01-01

    Graphical abstract: The thermal conductivity of PU was enhanced to 43 times of the pristine value by encapsulation in a PGF, PU@PGF can be used for highly efficient electro-to-heat energy conversion and storage with the highest energy storage efficiency up to 85%. - Highlights: • The composite exhibits an in-situ solid-solid phase change behavior. • The enthalpy of polyurethane is enhanced within the matrix. • The thermal conductivity of the composite is 43 times as much as that of the polyurethane. • Supercooling of polyurethane is greatly reduced. • The composite is applied to cold protection as a wear layer. - Abstract: A novel solid-to-solid phase change composite brick was prepared by combination of polyurethane (PU) and pitch-based graphite foam (PGF). The carbonaceous support, which can be used for mass production, not only greatly improves the thermal conductivity but promote electro-to-heat conversion efficiency of organic phase change materials (PCMs). Our composite retained the enthalpy of PCM and exhibited a greatly reduced supercooling temperature. The novel composite was investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). The enthalpy of polyurethane has increased about 8.6% after infiltrating into graphite foam. The composite was very stable during thermal cycle test, and the electro-to-heat conversion efficiency achieves to 85% at lower voltages (1.5–1.8 V), which can vastly reduce energy consumption. The as-prepared composite was used in a wear layer to test its performance comparing with normal fabric.

  19. Study on potency of municipal solid waste conversion into renewable energy by thermal incineration and bioconversion: case study of Medan city

    Science.gov (United States)

    Sarah, Maya; Misran, Erni

    2018-03-01

    Municipal solid waste (MSW) in Medan City is facing problems either with the quantity and management of MSW. Local authority only dumped approximately 73.9% MSW in the landfill over the years. Spontaneous phenomena of methane formation in dumping site indicates the potency of MSW conversion into energy by biochemical conversion. On the contrary, the presence of plastics, woods, papers, etc. in the MSW show the potency of MSW to be treated by thermal conversion. Both thermal incineration and anaerobic digestion may convert MSW Medan City into energy. This study evaluates potency of MSW conversion into renewable energy using proximate and ultimate analysis. Overall, MSW of Medan City has the opportunities to be converted into energy by both thermal and biochemical conversion with a special requirement such as pre-dry the MSW prior incineration process and degrade organic MSW in a bioreactor.

  20. 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.

  1. High efficiency direct thermal to electric energy conversion from radioisotope decay using selective emitters and spectrally tuned solar cells

    Science.gov (United States)

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

    1993-01-01

    Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1200K. Both selective emitter and filter system TPV systems are feasible. However, requirements on the filter system are severe in order to attain high efficiency. A thin-film of a rare-earth oxide is one method for producing an efficient, rugged selective emitter. An efficiency of 0.14 and power density of 9.2 W/KG at 1200K is calculated for a hypothetical thin-film neodymia (Nd2O3) selective emitter TPV system that uses radioisotope decay as the thermal energy source.

  2. High efficiency direct thermal to electric energy conversion from radioisotope decay using selective emitters and spectrally tuned solar cells

    International Nuclear Information System (INIS)

    Chubb, D.L.; Flood, D.J.; Lowe, R.A.

    1993-08-01

    Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1200K. Both selective emitter and filter system TPV systems are feasible. However, requirements on the filter system are severe in order to attain high efficiency. A thin-film of a rare-earth oxide is one method for producing an efficient, rugged selective emitter. An efficiency of 0.14 and power density of 9.2 W/KG at 1200K is calculated for a hypothetical thin-film neodymia (Nd2O3) selective emitter TPV system that uses radioisotope decay as the thermal energy source

  3. 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

  4. 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

  5. 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

  6. 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

  7. Synthesis and processing of materials for direct thermal-to-electric energy conversion and storage

    Science.gov (United States)

    Thompson, Travis

    Currently, fossil fuels are the primary source of energy. Mechanical heat engines convert the chemical potential energy in fossil fuels to useful electrical energy through combustion; a relatively low efficiency process that generates carbon dioxide. This practice has led to a significant increase in carbon dioxide emissions and is contributing to climate change. However, not all heat engines are mechanical. Alternative energy generation technologies to mechanical heat engines are known, yet underutilized. Thermoelectric generators are solid-state devices originally developed by NASA to power deep space spacecraft, which can also convert heat into electricity but without any moving parts. Similar to their mechanical counterparts, any heat source, including the burning of fossil fuels, can be used. However, clean heat sources, such as concentrated solar, can alternatively be used. Since the energy sources for many of the alternative energy technologies is intermittent, including concentrated solar for thermoelectric devices, load matching is difficult or impossible and an energy storage technology is needed in addition to the energy conversion technology. This increases the overall cost and complexity of the systems since two devices are required and represents a significant barrier for mass adoption of an alternative energy technology. However, it is possible to convert heat energy to electrical energy and store excess charge for use at a later time when the demand increases, in a single device. One such of a device is a thermogalvanic generator and is the electrochemical analog of electronic thermoelectric devices. Essentially, a thermogalvanic device represents the combination of thermoelectric and galvanic systems. As such, the rich history of strategies developed by both the thermoelectric community to better the performance of thermoelectric devices and by the electrochemical community to better traditional galvanic devices (i.e. batteries) can be applied to

  8. 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

  9. 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)

  10. Direct thermal to electrical energy conversion using 9.5/65/35 PLZT ceramics in the ergodic relaxor phase.

    Science.gov (United States)

    Chin, Thomas K; Lee, Felix Y; McKinley, Ian M; Goljahi, Sam; Lynch, Christopher S; Pilon, Laurent

    2012-11-01

    This paper reports on direct thermal to electrical energy conversion by performing the Olsen cycle on 9.5/65/35 lead lanthanum zirconate titanate (PLZT). The Olsen cycle consists of two isothermal and two isoelectric field processes in the electric displacement versus electric field diagram. It was performed by alternatively dipping the material in hot and cold dielectric fluid baths under specified electric fields. The effects of applied electric field, sample thickness, electrode material, operating temperature, and cycle frequency on the energy and power densities were investigated. A maximum energy density of 637 ± 20 J/L/cycle was achieved at 0.054 Hz with a 250-μm-thick sample featuring Pt electrodes and coated with a silicone conformal coating. The operating temperatures varied between 3°C and 140°C and the electric field was cycled between 0.2 and 6.0 MV/m. A maximum power density of 55 ± 8 W/L was obtained at 0.125 Hz under the same operating temperatures and electric fields. The dielectric strength of the material, and therefore the energy and power densities generated, increased when the sample thickness decreased from 500 to 250 μm. Furthermore, the electrode material was found to have no significant effect on the energy and power densities for samples subject to the same operating temperatures and electric fields. However, samples with electrode material possessing thermal expansion coefficients similar to that of PLZT were capable of withstanding larger temperature swings. Finally, a fatigue test showed that the power generation gradually degraded when the sample was subject to repeated thermoelectrical loading.

  11. Study of Thermally Responsive Ionic Liquids for Novel Water Desalination and Energy Conversion Applications

    KAUST Repository

    Zhong, Yujiang

    2018-01-01

    The rapidly expanding of the global population in the 21st-century forces people facing two serious problems: water scarcity and energy shortage. Enormous continuous studies focus on providing enough fresh water and energy in a sustainable way

  12. 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.

  13. 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

  14. 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

  15. 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

  16. A Preliminary Investigation of the Effect of Ocean Thermal Energy Conversion (OTEC Effluent Discharge Options on Global OTEC Resources

    Directory of Open Access Journals (Sweden)

    Gérard Nihous

    2018-03-01

    Full Text Available A simple algorithm previously used to evaluate steady-state global Ocean Thermal Energy Conversion (OTEC resources is extended to probe the effect of various effluent discharge methodologies. It is found that separate evaporator and condenser discharges potentially increase OTEC net power limits by about 60% over a comparable mixed discharge scenario. This stems from a relatively less severe degradation of the thermal resource at given OTEC seawater flow rates, which corresponds to a smaller heat input into the ocean. Next, the most practical case of a mixed discharge into the mixed layer is found to correspond to only 80% of the so-called baseline case (mixed discharge at a water depth of initial neutral buoyancy. In general, locating effluent discharges at initial neutral-buoyancy depths appears to be nearly optimal in terms of OTEC net power production limits. The depth selected for the OTEC condenser effluent discharge, however, has by far the greatest impact. Clearly, these results are preliminary and should be investigated in more complex ocean general circulation models.

  17. 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

  18. Catalysis for renewable energy and chemicals, the thermal conversion of biomass

    NARCIS (Netherlands)

    Janssen, F.J.J.G.; Janssen, F.J.J.G.; Santen, van R.A.

    1999-01-01

    The production of energy from fossil fuels gives rise to the emission of CO2, NO, and SO2. The amounts of these compounds formed during the production of energy from renewables such as wind, sun and biomass are less than those in case of fossil fuels. Therefore, research and development is carried

  19. 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)

  20. 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)

  1. 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.

  2. 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

  3. 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.

  4. 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)

  5. Results of scoping tests for open-cycle OTEC (ocean thermal energy conversion) components operating with seawater

    Energy Technology Data Exchange (ETDEWEB)

    Zangrando, F; Bharathan, D; Green, H J; Link, H F; Parsons, B K; Parsons, J M; Pesaran, A A [Solar Energy Research Inst., Golden, CO (USA); Panchal, C B [Argonne National Lab., IL (USA)

    1990-09-01

    This report presents comprehensive documentation of the experimental research conducted on open-cycle ocean thermal energy conversion (OC-OTEC) components operating with seawater as a working fluid. The results of this research are presented in the context of previous analysis and fresh-water testing; they provide a basis for understanding and predicting with confidence the performance of all components of an OC-OTEC system except the turbine. Seawater tests have confirmed the results that were obtained in fresh-water tests and predicted by the analytical models of the components. A sound technical basis has been established for the design of larger systems in which net power will be produced for the first time from OC-OTEC technology. Design and operation of a complete OC-OTEC system that produces power will provide sufficient confidence to warrant complete transfer of OC-OTEC technology to the private sector. Each components performance is described in a separate chapter written by the principal investigator responsible for technical aspects of the specific tests. Chapters have been indexed separately for inclusion on the data base.

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. Full-spectrum volumetric solar thermal conversion via photonic nanofluids.

    Science.gov (United States)

    Liu, Xianglei; Xuan, Yimin

    2017-10-12

    Volumetric solar thermal conversion is an emerging technique for a plethora of applications such as solar thermal power generation, desalination, and solar water splitting. However, achieving broadband solar thermal absorption via dilute nanofluids is still a daunting challenge. In this work, full-spectrum volumetric solar thermal conversion is demonstrated over a thin layer of the proposed 'photonic nanofluids'. The underlying mechanism is found to be the photonic superposition of core resonances, shell plasmons, and core-shell resonances at different wavelengths, whose coexistence is enabled by the broken symmetry of specially designed composite nanoparticles, i.e., Janus nanoparticles. The solar thermal conversion efficiency can be improved by 10.8% compared with core-shell nanofluids. The extinction coefficient of Janus dimers with various configurations is also investigated to unveil the effects of particle couplings. This work provides the possibility to achieve full-spectrum volumetric solar thermal conversion, and may have potential applications in efficient solar energy harvesting and utilization.

  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. Stearic-acid/carbon-nanotube composites with tailored shape-stabilized phase transitions and light–heat conversion for thermal energy storage

    International Nuclear Information System (INIS)

    Li, Benxia; Nie, Shibin; Hao, Yonggan; Liu, Tongxuan; Zhu, Jinbo; Yan, Shilong

    2015-01-01

    Highlights: • A facile preparation of shape-stabilized composite PCMs for thermal energy storage. • The composite PCMs present tunable phase change temperatures and enthalpy. • Sunlight-driven phase change for photothermal conversion and storage. - Abstract: The development of functional materials with both light–heat conversion and thermal energy storage properties is of crucial importance for efficient utilization of sunlight to meet the growing demand for sustainable energy. In this work, the shape-stabilized phase change composites were designed and prepared by integration of stearic acid (SA) and acid-treated carbon nanotubes (a-CNTs). The a-CNTs not only acted as a flexible matrix but also endowed the composites high light–heat conversion ability. The reversible phase transitions shifted from high temperatures (T m = 74 °C, T f = 57 °C) of pure SA to near room temperature (T m = ∼30 °C, T f = ∼22 °C) of SA/a-CNTs composites, probably resulting from the strong interface confinement effect. The phase change enthalpy of the SA/a-CNTs composite could also be tailored by changing the mass ratio of SA and a-CNTs. The composites containing SA of 54.2 wt.%, 67.8 wt.% and 79.5 wt.% presented the melting enthalpy of 76.3 J/g, 98.8 J/g and 111.8 J/g, respectively. Moreover, the phase transition of SA/a-CNTs composite could be driven by sunlight for the energy storage/release. Therefore, this research provides a new platform for improving solar utilization, and understanding the phase transition behaviors of organic PCMs in dimensionally confined environments as well

  15. Plasma Thermal Conversion of Methane to Acetylene

    International Nuclear Information System (INIS)

    Fincke, James Russell; Anderson, Raymond Paul; Hyde, Timothy Allen; Detering, Brent Alan; Wright, Randy Ben; Bewley, Randy Lee; Haggard, Delon C; Swank, William David

    2002-01-01

    This paper describes a re-examination of a known process for the direct plasma thermal conversion of methane to acetylene. Conversion efficiencies (% methane converted) approached 100% and acetylene yields in the 90-95% range with 2-4% solid carbon production were demonstrated. Specificity for acetylene was higher than in prior work. Improvements in conversion efficiency, yield, and specificity were due primarily to improved injector design and reactant mixing, and minimization of temperature gradients and cold boundary layers. At the 60-kilowatt scale cooling by wall heat transfer appears to be sufficient to quench the product stream and prevent further reaction of acetylene resulting in the formation of heavier hydrocarbon products or solid carbon. Significantly increasing the quenching rate by aerodynamic expansion of the products through a converging-diverging nozzle led to a reduction in the yield of ethylene but had little effect on the yield of other hydrocarbon products. While greater product selectivity for acetylene has been demonstrated, the specific energy consumption per unit mass of acetylene produced was not improved upon. A kinetic model that includes the reaction mechanisms resulting in the formation of acetylene and heavier hydrocarbons, through benzene, is described

  16. 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.

  17. 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.)

  18. 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.)

  19. 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.)

  20. Thermal Conversion of Methane to Acetylene

    Energy Technology Data Exchange (ETDEWEB)

    Fincke, James Russell; Anderson, Raymond Paul; Hyde, Timothy Allen; Wright, Randy Ben; Bewley, Randy Lee; Haggard, Delon C; Swank, William David

    2000-01-01

    This report describes the experimental demonstration of a process for the direct thermal conversion of methane to acetylene. The process utilizes a thermal plasma heat source to dissociation products react to form a mixture of acetylene and hydrogen. The use of a supersonic expansion of the hot gas is investigated as a method of rapidly cooling (quenching) the product stream to prevent further reaction or thermal decomposition of the acetylene which can lower the overall efficiency of the process.

  1. 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

  2. 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

  3. 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.)

  4. 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

  5. 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.

  6. 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.

  7. Review and summary of Solar Thermal Conversion Program planning assistance

    Energy Technology Data Exchange (ETDEWEB)

    1975-06-01

    The Solar Thermal Conversion Program comprises a major part of the national solar energy program which must be continuously reviewed and modified where necessary. Modifications are typically required to reflect technical achievements and uncertainties which arise from within the program or from other technical programs, changes in budgets available for supporting the program as well as internal program funding priorities, changing goals such as through acceleration or stretch-out of the program schedule, significant organizational changes involving responsible governmental agencies, the introduction of new project management support contractors, and required budget or schedule changes occurring within individual projects that make up the Solar Thermal Conversion Program. The Aerospace Corporation has provided data to assist in planning, review, coordination, and documentation of the overall Solar Thermal Conversion Program. The Solar Thermal Conversion Program Plan is described in detail. Sections 2.0 through 5.0 cover the discussion and detail planning covering the objectives, justification, basic and alternative plans, budgets, and schedules for the Solar Thermal sub-unit portion of the Solar Electric Applications effort. Appendices B1, B2, and B3 include the March 21, March 28, and April 5, 1975, Program Plan submissions of the complete Solar Electric Applications effort. In Appendix B the Solar Thermal, Solar Photovoltaic, Wind Energy, and Ocean Thermal sub-unit texts have been condensed and formatted for integration in the overall ERDA budget package. (WHK)

  8. 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. [...

  9. 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)

  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. 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)

  12. PBDOWN - a computer code for simulating core material discharge and thermal to mechanical energy conversion in LMFBR hypothetical accidents

    International Nuclear Information System (INIS)

    Royl, P.

    1981-01-01

    PBDOWN is a computer code that simulates the blowdown of confined boiling materials ('pools') into a colder upper coolant plenum as time dependent ejection and expansion with consideration of a few selected exchange processes. Its application is restricted to situations resulting from hypothetical loss of flow (LOF) accidents in LMFBR's, where enough voiding has occured, that in core sodium vapor pressures become negligible. PBDOWN considers one working fluid for the discharge process (either fuel or steel) and a maximum of two working fluids (either fuel and sodium or steel and sodium) for the expansion process in the upper coolant plenum. Entrainment of sodium at the accelerated bubble liquid interfaces is mechanistically calculated by a Taylor instability entrainment model. Simulation of a hemispherical expansion form together with this mechanistic entrainment model gives a new integrated calculation of the time dependent sodium mass in the bubble. The paper summarizes the basic equations and assumptions of this computer model. Sample results compare different heat transfer and Na entrainment models during steel and fuel driven discharge processes. Mechanistic sodium entrainment simulation for SNR-type reactors coupled with a realistic heat transfer model is shown to reduce the integral mechanical work potential by a factor of 1.3 to 2.0 over the isentropic energy of the discharge working fluids. (orig.)

  13. 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

  14. 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.

  15. 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

  16. 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).

  17. 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.

  18. 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

  19. Numerical conversion efficiency of thermally isolated Seebeck nanoantennas

    Directory of Open Access Journals (Sweden)

    Edgar Briones

    2016-11-01

    Full Text Available In this letter, we evaluate the conversion efficiency of thermally isolated Seebeck nanoantennas by numerical simulations and discuss their uses and scope for energy harvesting applications. This analysis includes the simple case of titanium-nickel dipoles suspended in air above the substrate by a 200 nm silicon dioxide membrane to isolate the heat dissipation. Results show that substantially thermal gradients are induced along the devices leading to a harvesting efficiency around 10-4 %, 400 % higher than the previously reported Seebeck nanoantennas. In the light of these results, different optimizing strategies should be considered in order to make the Seebeck nanoantennas useful for harvesting applications.

  20. 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...

  1. 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

  2. Thermal solar energy

    International Nuclear Information System (INIS)

    Gonzalez, J.C.; Leal C, H.

    1998-01-01

    Some relative aspects to the development and current state of thermal solar energy are summarized, so much at domestic level as international. To facilitate the criteria understanding as the size of the facilities in thermal solar systems, topics as availability of the solar resource and its interactions with the matter are included. Finally, some perspectives for the development of this energetic alternative are presented

  3. 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

  4. Warm Water Entrainment Impacts and Environmental Life Cycle Assessment of a Proposed Ocean Thermal Energy Conversion Pilot Plant Offshore Oahu, Hawaii

    Science.gov (United States)

    Hauer, Whitney Blanchard

    Ocean thermal energy conversion (OTEC) is a marine renewable energy technology that uses the temperature difference of large volumes of cold deep and warm surface seawater in tropical regions to generate electricity. One anticipated environmental impact of OTEC operations is the entrainment and subsequent mortality of ichthyoplankton (fish eggs and larvae) from the withdrawal of cold and warm seawater. The potential ichthyoplankton loss from the warm water intake was estimated for a proposed 10 MW OTEC pilot plant offshore Oahu, HI based on ambient vertical distribution data. The estimated losses due to entrainment from the warm water intake were 8.418E+02 larvae/1000 m3, 3.26E+06 larvae/day, and 1.19E+09 larvae/year. The potential entrained larvae/year is 1.86 X greater than at the Kahe Generating Station (Kapolei, HI), a 582 MW oil-fired power plant. Extrapolating to age-1 equivalence (9.2E+02 and 2.9E+02 yellowfin and skipjack tuna, respectively), the estimated yearly losses from warm water entrainment of yellowfin and skipjack tuna fish eggs and larvae represent 0.25-0.26 % and 0.09-0.11 % of Hawaii's commercial yellowfin and skipjack tuna industry in 2011 and 2012. An environmental life cycle assessment (LCA) was developed for the proposed OTEC plant operating for 20 and 40 years with availability factors of 0.85, 0.95, and 1.0 to determine the global warming potential (GWP) and cumulative energy demand (CED) impacts. For a 20 year operational OTEC plant, the GWP, CED, energy return on investment (EROI), and energy payback time (EPBT) ranged from 0.047 to 0.055 kg CO2eq/kWh, 0.678 to 0.798 MJ/kWh, 4.51 to 5.31 (unitless), and 3.77 to 4.43 years, respectively. For a 40 year operational OTEC plant, the GWP, CED, EROI, and EBPT ranged from 0.036 to 0.043 kg CO2eq/kWh, 0.527 to 0.620 MJ/kWh, 5.81 to 6.83 (unitless), and 5.85 to 6.89 years, respectively. The GWP impacts are within the range of renewable energy technologies and less than conventional electricity

  5. 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.

  6. 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.

  7. Hybrid energy harvesting using active thermal backplane

    Science.gov (United States)

    Kim, Hyun-Wook; Lee, Dong-Gun

    2016-04-01

    In this study, we demonstrate the concept of a new hybrid energy harvesting system by combing solar cells with magneto-thermoelectric generator (MTG, i.e., thermal energy harvesting). The silicon solar cell can easily reach high temperature under normal operating conditions. Thus the heated solar cell becomes rapidly less efficient as the temperature of solar cell rises. To increase the efficiency of the solar cell, air or water-based cooling system is used. To surpass conventional cooling devices requiring additional power as well as large working space for air/water collectors, we develop a new technology of pairing an active thermal backplane (ATB) to solar cell. The ATB design is based on MTG technology utilizing the physics of the 2nd order phase transition of active ferromagnetic materials. The MTG is cost-effective conversion of thermal energy to electrical energy and is fundamentally different from Seebeck TEG devices. The ATB (MTG) is in addition to being an energy conversion system, a very good conveyor of heat through both conduction and convection. Therefore, the ATB can provide dual-mode for the proposed hybrid energy harvesting. One is active convective and conductive cooling for heated solar cell. Another is active thermal energy harvesting from heat of solar cell. These novel hybrid energy harvesting device have potentially simultaneous energy conversion capability of solar and thermal energy into electricity. The results presented can be used for better understanding of hybrid energy harvesting system that can be integrated into commercial applications.

  8. 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.

  9. 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.

  10. Solar thermal energy receiver

    Science.gov (United States)

    Baker, Karl W. (Inventor); Dustin, Miles O. (Inventor)

    1992-01-01

    A plurality of heat pipes in a shell receive concentrated solar energy and transfer the energy to a heat activated system. To provide for even distribution of the energy despite uneven impingement of solar energy on the heat pipes, absence of solar energy at times, or failure of one or more of the heat pipes, energy storage means are disposed on the heat pipes which extend through a heat pipe thermal coupling means into the heat activated device. To enhance energy transfer to the heat activated device, the heat pipe coupling cavity means may be provided with extensions into the device. For use with a Stirling engine having passages for working gas, heat transfer members may be positioned to contact the gas and the heat pipes. The shell may be divided into sections by transverse walls. To prevent cavity working fluid from collecting in the extensions, a porous body is positioned in the cavity.

  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. 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

  13. 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%.

  14. 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.

  15. 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.

  16. 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)

  17. 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)

  18. 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

  19. 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...

  20. 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...

  1. 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.

  2. 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...

  3. 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.

  4. 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)

  5. 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

  6. Performance study of a laboratory model shallow solar pond with and without single transparent glass cover for solar thermal energy conversion applications.

    Science.gov (United States)

    Ganesh, S; Arumugam, S

    2016-12-01

    The thermal performance of a shallow solar pond with and without the single transparent glass cover has been investigated experimentally. This experiment has been performed during the summer season of 2014 under the operational condition for five different storage volumes of water upto a maximum of 10liter. The pond performance is investigated in terms of the rate of energy collected and its collection efficiency. A Low Density Polyethylene (LDPE) black sheet liner of 200μm thickness was laid on all the interior sides of the pond for solar energy absorption. A clear transparent PVC plastic sheet of 150μm thickness was laid over the water surface as evaporation suppressing membrane. Calibrated Copper constantan thermocouples were used to measure the temperatures of the system. A highest temperature of 81.5°C has been achieved for the stored volume of 2liter of water, when the pond was used with a single transparent glass cover of 5mm thickness. When the shallow solar pond was used without the transparent glass cover the system attained a maximum temperature of 62°C for the same stored volume of 2liter. A comparison between the two conditions of with and without the transparent glass cover, on the thermal performance of the SSP has been reported. A shallow solar pond system of the present type could be used us a source of warm water, of desired temperature, below 10°C which are required for the domestic and industrial utilities. The global warming is increased day by day; inorder to reduce global warming a typical method of small scale shallow solar pond has been used to absorb the radiation from the sun to convert it to useful heat energy by the source of water. The SSP is an eco friendly way to generate energy without polluting our environment and in an environment safety manner. Based on environmental safety this study has experimentally investigated the thermal performance of the shallow solar pond. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. 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.)

  8. Materials for Energy Conversion: Materials for Energy Conversion and Storage

    Energy Technology Data Exchange (ETDEWEB)

    Atanassov, Plamen [Univ. of New Mexico, Albuquerque, NM (United States)

    2017-03-30

    The main objective of this collaborative research project was to identify a formulation and develop a catalyst for electro-oxidation of ethanol. Ethanol is one of the most mass-produced biofuels, and such catalysts will enable the development of Direct Ethanol Fuel Cell technology and through it, will interconnect fuel cells with biofuels. Several catalysts for direct electrochemical oxidation of ethanol have been selected on the principles of rational desig from the knowledge build in studying aqueous oxidation of ethanol. The program involved fundamental study of ethanol oxidation in liquid media, and particularly in alakine solutions. The lessons learned from the heterogeneous catalysis of ethanol thermal oxidation have been applied to the design of an electrocatalyst for direct ethanol fuel cells. The successful chemical compositions are based on PdZn and NiZn allows. The studies reveled the role of the transition metal oxide phase as a co-catalyst and the role of the active support material. To complete the set of materials for ethanol fuel cell, this program also invested n the development of ctalysts for oxygen reduction that are selective against alcohol oxidation. Non-platinum ctalysts based on pyrolyzed macrocycles or similar composites have been studied. This program included also the development of stuctured supports as an integral part of the catalyst development. A new family of materials has been designed based on mesoporous silica templating with synthetic carbon resulting in hierarchicaly porous structure. Structure-to-property relationship of catalysis and catalysts has been the center of this program. This have been engaged in both surface and bulk level and pursued with the tools avialble at the academic institutions and at LANSCE at LANL. The structural studies have been built in interaction with a computational effort on the basis of DFT approach to materials structure and reactivity.

  9. 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...

  10. 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...

  11. 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

  12. 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 ...

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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)

  18. 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)

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Waste energy harvesting mechanical and thermal energies

    CERN Document Server

    Ling Bing, Kong; Hng, Huey Hoon; Boey, Freddy; Zhang, Tianshu

    2014-01-01

    Waste Energy Harvesting overviews the latest progress in waste energy harvesting technologies, with specific focusing on waste thermal mechanical energies. Thermal energy harvesting technologies include thermoelectric effect, storage through phase change materials and pyroelectric effect. Waste mechanical energy harvesting technologies include piezoelectric (ferroelectric) effect with ferroelectric materials and nanogenerators. The book aims to strengthen the syllabus in energy, materials and physics and is well suitable for students and professionals in the fields.

  4. 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.

  5. 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.)

  6. Aquifer thermal energy (heat and chill) storage

    Energy Technology Data Exchange (ETDEWEB)

    Jenne, E.A. (ed.)

    1992-11-01

    As part of the 1992 Intersociety Conversion Engineering Conference, held in San Diego, California, August 3--7, 1992, the Seasonal Thermal Energy Storage Program coordinated five sessions dealing specifically with aquifer thermal energy storage technologies (ATES). Researchers from Sweden, The Netherlands, Germany, Switzerland, Denmark, Canada, and the United States presented papers on a variety of ATES related topics. With special permission from the Society of Automotive Engineers, host society for the 1992 IECEC, these papers are being republished here as a standalone summary of ATES technology status. Individual papers are indexed separately.

  7. 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.

  8. 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.

  9. Basic study on an energy conversion system using boiling two-phase flows of temperature-sensitive magnetic fluid. Theoretical analysis based on thermal nonequilibrium model and flow visualization using ultrasonic echo

    International Nuclear Information System (INIS)

    Ishimoto, Jun; Kamiyama, Shinichi; Okubo, Masaaki.

    1995-01-01

    Effects of magnetic field on the characteristics of boiling two-phase pipe flow of temperature-sensitive magnetic fluid are clarified in detail both theoretically and experimentally. Firstly, governing equations of two-phase magnetic fluid flow based on the thermal nonequilibrium two-fluid model are presented and numerically solved considering evaporation and condensation between gas- and liquid-phases. Next, behaviour of vapor bubbles is visualized with ultrasonic echo in the region of nonuniform magnetic field. This is recorded and processed with an image processor. As a result, the distributions of void fraction in the two-phase flow are obtained. Furthermore, detailed characteristics of the two-phase magnetic fluid flow are investigated using a small test loop of the new energy conversion system. From the numerical and experimental results, it is known that the precise control of the boiling two-phase flow and bubble generation is possible by using the nonuniform magnetic field effectively. These fundamental studies on the characteristics of two-phase magnetic fluid flow will contribute to the development of the new energy conversion system using a gas-liquid boiling two-phase flow of magnetic fluid. (author)

  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. 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.

  12. 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.

  13. 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

  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. 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)

  17. 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

  18. 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

  19. 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

  20. A review on photo-thermal catalytic conversion of carbon dioxide

    Directory of Open Access Journals (Sweden)

    Ee Teng Kho

    2017-07-01

    Full Text Available The conversion of carbon dioxide into value-added products is of great industrial and environmental interest. However, as carbon dioxide is relatively stable, the input energy required for this conversion is a significant limiting factor in the system's performance. By utilising energy from the sun, through a range of key routes, this limitation can be overcome. In this review, we present a comprehensive and critical overview of the potential routes to harvest the sun's energy, primarily through solar-thermal technologies and plasmonic resonance effects. Focusing on the localised heating approach, this review shortlists and compares viable catalysts for the photo-thermal catalytic conversion of carbon dioxide. Further, the pathways and potential products of different carbon dioxide conversion routes are outlined with the reverse water gas shift, methanation, and methanol synthesis being of key interest. Finally, the challenges in implementing such systems and the outlook to the future are detailed. Keywords: Carbon dioxide conversion, Photo-thermal, Plasmonic catalysis, Solar thermal

  1. 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.

  2. 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)

  3. 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

  4. 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.)

  5. 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.

  6. 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

  7. Disintegration of beech wood char during thermal conversion

    DEFF Research Database (Denmark)

    Hindsgaul, Claus

    In the present work the processes occurring in the structures of slowly pyrolysed beech wood char during thermal gasification have been investigated. Emphasis was put on physical changes and gas transport properties during conversion. The highly anisotropic structure of wood was preserved in its ...

  8. Scalable, "Dip-and-Dry" Fabrication of a Wide-Angle Plasmonic Selective Absorber for High-Efficiency Solar-Thermal Energy Conversion.

    Science.gov (United States)

    Mandal, Jyotirmoy; Wang, Derek; Overvig, Adam C; Shi, Norman N; Paley, Daniel; Zangiabadi, Amirali; Cheng, Qian; Barmak, Katayun; Yu, Nanfang; Yang, Yuan

    2017-11-01

    A galvanic-displacement-reaction-based, room-temperature "dip-and-dry" technique is demonstrated for fabricating selectively solar-absorbing plasmonic-nanoparticle-coated foils (PNFs). The technique, which allows for facile tuning of the PNFs' spectral reflectance to suit different radiative and thermal environments, yields PNFs which exhibit excellent, wide-angle solar absorptance (0.96 at 15°, to 0.97 at 35°, to 0.79 at 80°), and low hemispherical thermal emittance (0.10) without the aid of antireflection coatings. The thermal emittance is on par with those of notable selective solar absorbers (SSAs) in the literature, while the wide-angle solar absorptance surpasses those of previously reported SSAs with comparable optical selectivities. In addition, the PNFs show promising mechanical and thermal stabilities at temperatures of up to 200 °C. Along with the performance of the PNFs, the simplicity, inexpensiveness, and environmental friendliness of the "dip-and-dry" technique makes it an appealing alternative to current methods for fabricating selective solar absorbers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Plasma thermal conversion of bio-oil for hydrogen production

    International Nuclear Information System (INIS)

    Guenadou, David; Lorcet, Helene; Peybernes, Jean; Catoire, Laurent; Osmont, Antoine; Gokalp, Iskender

    2012-01-01

    Numerous processes exist or are proposed for the energetic conversion of biomass. The use of thermal plasma is proposed in the frame of the GALACSY project for the conversion of bio-oil to hydrogen and carbon monoxide. For this purpose, an experimental apparatus has been built. The feasibility of this conversion at very high temperature, as encountered in thermal plasma, is examined both experimentally and numerically. This zero dimensional study tends to show that a high temperature (around 2500 K or above) is needed to ensure a high yield of hydrogen (about 50 mol%) and about 95 mol% of CO+H 2 . Predicted CO+H 2 yield and CO/H 2 ratio are consistent with measurements. It is also expected that the formation of particles and tars is hampered. Thermodynamic data of selected bio-oil components are provided in the CHEMKINNASA format. (authors)

  10. 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)

  11. The total flow concept for geothermal energy conversion

    Science.gov (United States)

    Austin, A. L.

    1974-01-01

    A geothermal development project has been initiated at the Lawrence Livermore Laboratory (LLL) to emphasize development of methods for recovery and conversion of the energy in geothermal deposits of hot brines. Temperatures of these waters vary from 150 C to more than 300 C with dissolved solids content ranging from less than 0.1% to over 25% by weight. Of particular interest are the deposits of high-temperature/high-salinity brines, as well as less saline brines, known to occur in the Salton Trough of California. Development of this resource will depend on resolution of the technical problems of brine handling, scale and precipitation control, and corrosion/erosion resistant systems for efficient conversion of thermal to electrical energy. Research experience to date has shown these problems to be severe. Hence, the LLL program emphasizes development of an entirely different approach called the Total Flow concept.

  12. Phase-Change Thermal Energy Storage

    Science.gov (United States)

    1989-11-01

    The goal of this program is to advance the engineering and scientific understanding of solar thermal technology and to establish the technology base from which private industry can develop solar thermal power production options for introduction into the competitive energy market. Solar thermal technology concentrates the solar flux using tracking mirrors or lenses onto a receiver where the solar energy is absorbed as heat and converted into electricity or incorporated into products as process heat. The two primary solar thermal technologies, central receivers and distributed receivers, employ various point and line-focus optics to concentrate sunlight. Current central receiver systems use fields of heliostats (two-axes tracking mirrors) to focus the sun's radiant energy onto a single, tower-mounted receiver. Point focus concentrators up to 17 meters in diameter track the sun in two axes and use parabolic dish mirrors or Fresnel lenses to focus radiant energy onto a receiver. Troughs and bowls are line-focus tracking reflectors that concentrate sunlight onto receiver tubes along their focal lines. Concentrating collector modules can be used alone or in a multimodule system. The concentrated radiant energy absorbed by the solar thermal receiver is transported to the conversion process by a circulating working fluid. Receiver temperatures range from 100 C in low-temperature troughs to over 1500 C in dish and central receiver systems.

  13. Thermal energy at the nanoscale

    CERN Document Server

    Fisher, Timothy S

    2014-01-01

    These lecture notes provide a detailed treatment of the thermal energy storage and transport by conduction in natural and fabricated structures. Thermal energy in two carriers, i.e. phonons and electrons -- are explored from first principles. For solid-state transport, a common Landauer framework is used for heat flow. Issues including the quantum of thermal conductance, ballistic interface resistance, and carrier scattering are elucidated. Bulk material properties, such as thermal and electrical conductivity, are derived from particle transport theories, and the effects of spatial confinement on these properties are established. Readership: Students and professionals in physics and engineering.

  14. 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.

  15. Investigation of Solar and Solar-Gas Thermal Energy Sources

    OpenAIRE

    Ivan Herec; Jan Zupa

    2003-01-01

    The article deals with the investigation of solar thermal sources of electrical and heat energy as well as the investigation of hybrid solar-gas thermal sources of electrical and heat energy (so called photothermal sources). Photothermal sources presented here utilize computer-controlled injection of the conversion fluid into special capillary porous substance that is adjusted to direct temperature treatment by the concentrated thermal radiation absorption.

  16. Ocean Thermal Extractable Energy Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Ascari, Matthew [Lockheed Martin Corporation, Bethesda, MD (United States)

    2012-10-28

    The Ocean Thermal Extractable Energy Visualization (OTEEV) project focuses on assessing the Maximum Practicably Extractable Energy (MPEE) from the world’s ocean thermal resources. MPEE is defined as being sustainable and technically feasible, given today’s state-of-the-art ocean energy technology. Under this project the OTEEV team developed a comprehensive Geospatial Information System (GIS) dataset and software tool, and used the tool to provide a meaningful assessment of MPEE from the global and domestic U.S. ocean thermal resources.

  17. 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)

  18. 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.

  19. 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.

  20. 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.

  1. Design and analysis of Helium Brayton cycle for energy conversion system of RGTT200K

    International Nuclear Information System (INIS)

    Ignatius Djoko Irianto

    2016-01-01

    The helium Brayton cycle for the design of cogeneration energy conversion system for RGTT200K have been analyzed to obtain the higher thermal efficiency and energy utilization factor. The aim of this research is to analyze the potential of the helium Brayton cycle to be implemented in the design of cogeneration energy conversion system of RGTT200K. Three configuration models of cogeneration energy conversion systems have been investigated. In the first configuration model, an intermediate heat exchanger (IHX) is installed in series with the gas turbine, while in the second configuration model, IHX and gas turbines are installed in parallel. The third configuration model is similar to the first configuration, but with two compressors. Performance analysis of Brayton cycle used for cogeneration energy conversion system of RGTT200K has been done by simulating and calculating using CHEMCAD code. The simulation result shows that the three configuration models of cogeneration energy conversion system give the temperature of thermal energy in the secondary side of IHX more than 800 °C at the reactor coolant mass flow rate of 145 kg/s. Nevertheless, the performance parameters, which include thermal efficiency and energy utilization factor (EUF), are different for each configuration model. By comparing the performance parameter in the three configurations of helium Brayton cycle for cogeneration energy conversion systems RGTT200K, it is found that the energy conversion system with a first configuration has the highest thermal efficiency and energy utilization factor (EUF). Thermal efficiency and energy utilization factor for the first configuration of the reactor coolant mass flow rate of 145 kg/s are 35.82 % and 80.63 %. (author)

  2. 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)

  3. 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.

  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.; 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).

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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).

  15. 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.

  16. 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.

  17. 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.

  18. Overall efficiencies for conversion of solar energy to a chemical fuel

    Science.gov (United States)

    Fish, J. D.

    A complete and consistent scheme for determining the overall efficiency of a generalized process for the conversion of solar energy into a chemical fuel (e.g. hydrogen) is developed and applied to seven conversion processes: thermal, thermochemical, photovoltaic, photogalvanic, photoelectrolysis, photosynthesis and photochemical conversion. It is demonstrated that the overall efficiency of each of these processes is determined by ten common factors: maximum theoretical efficiency, inherent absorption losses, inherent internal losses, rate limiting effects, reflection losses, transmission losses, coverage losses, system construction requirements, parasitic losses and harvesting and conversion losses. Both state-of-the-art and optimistic values are assigned to each factor for each of the seven conversion processes. State-of-the-art overall efficiencies ranged from 5% for thermal conversion down to essentially zero for thermochemical. Optimistic values in the range of about 10 to 15% are calculated for several of the processes.

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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.)

  4. 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

  5. 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.

  6. A thermal engine for underwater glider driven by ocean thermal energy

    International Nuclear Information System (INIS)

    Yang, Yanan; Wang, Yanhui; Ma, Zhesong; Wang, Shuxin

    2016-01-01

    Highlights: • Thermal engine with a double-tube structure is developed for underwater glider. • Isostatic pressing technology is effective to increase volumetric change rate. • Actual volumetric change rate reaches 89.2% of the theoretical value. • Long term sailing of 677 km and 27 days is achieved by thermal underwater glider. - Graphical Abstract: - Abstract: Underwater glider is one of the most popular platforms for long term ocean observation. Underwater glider driven by ocean thermal energy extends the duration and range of underwater glider powered by battery. Thermal engine is the core device of underwater glider to harvest ocean thermal energy. In this paper, (1) model of thermal engine was raised by thermodynamics method and the performance of thermal engine was investigated, (2) thermal engine with a double-tube structure was developed and isostatic pressing technology was applied to improve the performance for buoyancy driven, referencing powder pressing theory, (3) wall thickness of thermal engine was optimized to reduce the overall weight of thermal engine, (4) material selection and dimension determination were discussed for a faster heat transfer design, by thermal resistance analysis, (5) laboratory test and long term sea trail were carried out to test the performance of thermal engine. The study shows that volumetric change rate is the most important indicator to evaluating buoyancy-driven performance of a thermal engine, isostatic pressing technology is effective to improve volumetric change rate, actual volumetric change rate can reach 89.2% of the theoretical value and the average power is about 124 W in a typical diving profile. Thermal engine developed by Tianjin University is a superior thermal energy conversion device for underwater glider. Additionally, application of thermal engine provides a new solution for miniaturization of ocean thermal energy conversion.

  7. 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.

  8. 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).

  9. 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)

  10. 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...

  11. 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.…

  12. 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

  13. Aquifer Thermal Energy Storage for Seasonal Thermal Energy Balance

    Science.gov (United States)

    Rostampour, Vahab; Bloemendal, Martin; Keviczky, Tamas

    2017-04-01

    Aquifer Thermal Energy Storage (ATES) systems allow storing large quantities of thermal energy in subsurface aquifers enabling significant energy savings and greenhouse gas reductions. This is achieved by injection and extraction of water into and from saturated underground aquifers, simultaneously. An ATES system consists of two wells and operates in a seasonal mode. One well is used for the storage of cold water, the other one for the storage of heat. In warm seasons, cold water is extracted from the cold well to provide cooling to a building. The temperature of the extracted cold water increases as it passes through the building climate control systems and then gets simultaneously, injected back into the warm well. This procedure is reversed during cold seasons where the flow direction is reversed such that the warmer water is extracted from the warm well to provide heating to a building. From the perspective of building climate comfort systems, an ATES system is considered as a seasonal storage system that can be a heat source or sink, or as a storage for thermal energy. This leads to an interesting and challenging optimal control problem of the building climate comfort system that can be used to develop a seasonal-based energy management strategy. In [1] we develop a control-oriented model to predict thermal energy balance in a building climate control system integrated with ATES. Such a model however cannot cope with off-nominal but realistic situations such as when the wells are completely depleted, or the start-up phase of newly installed wells, etc., leading to direct usage of aquifer ambient temperature. Building upon our previous work in [1], we here extend the mathematical model for ATES system to handle the above mentioned more realistic situations. Using our improved models, one can more precisely predict system behavior and apply optimal control strategies to manage the building climate comfort along with energy savings and greenhouse gas reductions

  14. Rapid charging of thermal energy storage materials through plasmonic heating.

    Science.gov (United States)

    Wang, Zhongyong; Tao, Peng; Liu, Yang; Xu, Hao; Ye, Qinxian; Hu, Hang; Song, Chengyi; Chen, Zhaoping; Shang, Wen; Deng, Tao

    2014-09-01

    Direct collection, conversion and storage of solar radiation as thermal energy are crucial to the efficient utilization of renewable solar energy and the reduction of global carbon footprint. This work reports a facile approach for rapid and efficient charging of thermal energy storage materials by the instant and intense photothermal effect of uniformly distributed plasmonic nanoparticles. Upon illumination with both green laser light and sunlight, the prepared plasmonic nanocomposites with volumetric ppm level of filler concentration demonstrated a faster heating rate, a higher heating temperature and a larger heating area than the conventional thermal diffusion based approach. With controlled dispersion, we further demonstrated that the light-to-heat conversion and thermal storage properties of the plasmonic nanocomposites can be fine-tuned by engineering the composition of the nanocomposites.

  15. 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.)

  16. Thermal energy storage devices, systems, and thermal energy storage device monitoring methods

    Science.gov (United States)

    Tugurlan, Maria; Tuffner, Francis K; Chassin, David P.

    2016-09-13

    Thermal energy storage devices, systems, and thermal energy storage device monitoring methods are described. According to one aspect, a thermal energy storage device includes a reservoir configured to hold a thermal energy storage medium, a temperature control system configured to adjust a temperature of the thermal energy storage medium, and a state observation system configured to provide information regarding an energy state of the thermal energy storage device at a plurality of different moments in time.

  17. 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)

  18. 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

  19. Radiation-thermal processes of conversion in the coals

    International Nuclear Information System (INIS)

    Mustafaev, I.I.

    2002-01-01

    Full text: The brief review, history, modern condition and bibliographic data on research of radiation-stimulated processes in coals are adduced in the report. Results of new researches of influence of gamma - radiation and accelerated electrons on pyrolysis, gasification, desulphurization, paramagnetism, adsorption and optical properties of coals in wide intervals of change of absorbed dose, dose rate, temperature, radiation type and other parameters of processes are stated. As object of researches Turkish (Yeni koy, Yatagan) and Russian (Siberia) coals were used. Specific peculiarities of influence of ionizing radiations on fossil fuels, bringing in change of their reactivity as result of destruction and polycondensation processes are considered. a)Pyrolysis: Under action of gamma-radiation and accelerated electrons the rate of thermal (t) pyrolysis grows and the ratio of radiation-thermal (rt) and thermal (t) processes: Wrt/ Wt depends on dose rate and temperature. By increase of dose rate the radiation effects grows, and at increase of temperature this effect is reduced. The influence of high rate heating of coals under pulls action of accelerated electrons on conversion degree and product composition has been established. The investigation regularities of formation liquid and gas products is resulted at radiation - thermal processing of mixtures of lignites with fuel oil. These experiments were conducted in flowing conditions in the interval of temperature T=350-500 degrees centigrade, power of the pulls accelerated electrons P=30-50 W, flow velocity of fuel oil 0,2-2 ml/minute. As a index of process were controlled conversion degree of coals, overall yield, contents and characteristic of liquid and gas products. The products of thermal treatment of these mixtures and also radiation-thermal treatment of separate components significantly less than radiation-thermal conversion of binary mixtures. It has been established that radiation effect has a positive

  20. 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

  1. 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

  2. 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

  3. Local Thermal Insulating Materials For Thermal Energy Storage ...

    African Journals Online (AJOL)

    Thermal insulation is one of the most important components of a thermal energy storage system. In this paper the thermal properties of selected potential local materials which can be used for high temperature insulation are presented. Thermal properties of seven different samples were measured. Samples consisted of: ...

  4. Microwavable thermal energy storage material

    Science.gov (United States)

    Salyer, I.O.

    1998-09-08

    A microwavable thermal energy storage material is provided which includes a mixture of a phase change material and silica, and a carbon black additive in the form of a conformable dry powder of phase change material/silica/carbon black, or solid pellets, films, fibers, moldings or strands of phase change material/high density polyethylene/ethylene vinyl acetate/silica/carbon black which allows the phase change material to be rapidly heated in a microwave oven. The carbon black additive, which is preferably an electrically conductive carbon black, may be added in low concentrations of from 0.5 to 15% by weight, and may be used to tailor the heating times of the phase change material as desired. The microwavable thermal energy storage material can be used in food serving applications such as tableware items or pizza warmers, and in medical wraps and garments. 3 figs.

  5. Experimental investigation of an optical water filter for Photovoltaic/Thermal conversion module

    International Nuclear Information System (INIS)

    Al-Shohani, Wisam A.M.; Sabouri, Aydin; Al-Dadah, Raya; Mahmoud, Saad; Butt, Haider

    2016-01-01

    Highlights: • New design of Photovoltaic/Thermal system is proposed. • Using the optical water layer as a spectrum splitter is tested experimentally. • Optical rig is developed to study the optical performance of water layer. • Energy conversion under different water layer thicknesses is determined. - Abstract: This paper presents an experimental investigation of a novel optical water filter used for Photovoltaic/Thermal and Concentrating Photovoltaic/Thermal modules. A water layer is used as a spectrum splitter of solar radiation placed above the photovoltaic cells and as a thermal working fluid simultaneously. The water layer absorbs the ultraviolet and part of infrared, which are not used by the photovoltaic, but transmits the visible and some of infrared to the solar cell surface which are used by the photovoltaic. In this work, the transmittance of the optical water filter was measured for different water thicknesses (1, 2, 3, 4, and 5 cm) and radiation wavelength ranging from 0.35 to 1 μm. Results show that there is a significant effect of the water layer thickness on the transmittance of the spectra where the transmittance decreases as the water layer increases. Moreover, energy conversion rate of photovoltaic with the optical water filter at different water layer thicknesses has been determined.

  6. Efficient Solar-Thermal Energy Harvest Driven by Interfacial Plasmonic Heating-Assisted Evaporation.

    Science.gov (United States)

    Chang, Chao; Yang, Chao; Liu, Yanming; Tao, Peng; Song, Chengyi; Shang, Wen; Wu, Jianbo; Deng, Tao

    2016-09-07

    The plasmonic heating effect of noble nanoparticles has recently received tremendous attention for various important applications. Herein, we report the utilization of interfacial plasmonic heating-assisted evaporation for efficient and facile solar-thermal energy harvest. An airlaid paper-supported gold nanoparticle thin film was placed at the thermal energy conversion region within a sealed chamber to convert solar energy into thermal energy. The generated thermal energy instantly vaporizes the water underneath into hot vapors that quickly diffuse to the thermal energy release region of the chamber to condense into liquids and release the collected thermal energy. The condensed water automatically flows back to the thermal energy conversion region under the capillary force from the hydrophilic copper mesh. Such an approach simultaneously realizes efficient solar-to-thermal energy conversion and rapid transportation of converted thermal energy to target application terminals. Compared to conventional external photothermal conversion design, the solar-thermal harvesting device driven by the internal plasmonic heating effect has reduced the overall thermal resistance by more than 50% and has demonstrated more than 25% improvement of solar water heating efficiency.

  7. More Efficient Solar Thermal-Energy Receiver

    Science.gov (United States)

    Dustin, M. O.

    1987-01-01

    Thermal stresses and reradiation reduced. Improved design for solar thermal-energy receiver overcomes three major deficiencies of solar dynamic receivers described in literature. Concentrator and receiver part of solar-thermal-energy system. Receiver divided into radiation section and storage section. Concentrated solar radiation falls on boiling ends of heat pipes, which transmit heat to thermal-energy-storage medium. Receiver used in number of applications to produce thermal energy directly for use or to store thermal energy for subsequent use in heat engine.

  8. 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.

  9. Conversion of magnetic energy to runaway kinetic energy during the termination of runaway current on the J-TEXT tokamak

    Science.gov (United States)

    Dai, A. J.; Chen, Z. Y.; Huang, D. W.; Tong, R. H.; Zhang, J.; Wei, Y. N.; Ma, T. K.; Wang, X. L.; Yang, H. Y.; Gao, H. L.; Pan, Y.; the J-TEXT Team

    2018-05-01

    A large number of runaway electrons (REs) with energies as high as several tens of mega-electron volt (MeV) may be generated during disruptions on a large-scale tokamak. The kinetic energy carried by REs is eventually deposited on the plasma-facing components, causing damage and posing a threat on the operation of the tokamak. The remaining magnetic energy following a thermal quench is significant on a large-scale tokamak. The conversion of magnetic energy to runaway kinetic energy will increase the threat of runaway electrons on the first wall. The magnetic energy dissipated inside the vacuum vessel (VV) equals the decrease of initial magnetic energy inside the VV plus the magnetic energy flowing into the VV during a disruption. Based on the estimated magnetic energy, the evolution of magnetic-kinetic energy conversion are analyzed through three periods in disruptions with a runaway current plateau.

  10. 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.

  11. 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.

  12. Thermal performance and heat transport in aquifer thermal energy storage

    NARCIS (Netherlands)

    Sommer, W.T.; Doornenbal, P.J.; Drijver, B.C.; Gaans, van P.F.M.; Leusbrock, I.; Grotenhuis, J.T.C.; Rijnaarts, H.H.M.

    2014-01-01

    Aquifer thermal energy storage (ATES) is used for seasonal storage of large quantities of thermal energy. Due to the increasing demand for sustainable energy, the number of ATES systems has increased rapidly, which has raised questions on the effect of ATES systems on their surroundings as well as

  13. Experimental model for architectural systematization and its basic thermal performance. Part 1. Research on architectural systematization of energy conversion devices; Kenchiku system ka model no gaiyo to kihon seino ni tsuite. 1. Energy henkan no kenchiku system ka ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Sunaga, N; Ito, N; Kimura, G; Fukao, S; Shimizu, T; Tsunoda, M; Muro, K [Tokyo Metropolitan University, Tokyo (Japan)

    1996-10-27

    The outline of a model for architectural systematization of natural energy conversion and the experiment result on the basic thermal performance in winter are described. The model is about 20 m{sup 2} in floor space. Foam polystyrene of 100 mm and 200 mm thick was used for the outer wall as heat insulating materials. The model has a solar battery and air conditioner and uses red brick as a heat reservoir. An experiment was made on seven modes obtained when three elements (heating, heat storage, and night insulated door) are combined. The information obtained by the experiment showed that a model for architectural systematization has high heat insulation and tightness and can be used as an energy element or an evaluation model for architectural systematization. In this model for architectural systematization, the power consumption of an air conditioner in winter can be fully supplied by only the power generation based on a solar battery. In an architectural element, the heating energy consumption can be remarkably reduced and the indoor thermal environment can be greatly improved, by the combination of a heat reservoir and night heat insulated door. 1 ref., 6 figs., 3 tabs.

  14. Energy Conversion Mechanism for Electron Perpendicular Energy in High Guide-Field Reconnection

    Science.gov (United States)

    Guo, Xuehan; Horiuchi, Ritoku; Kaminou, Yasuhiro; Cheng, Frank; Ono, Yasushi

    2016-10-01

    The energy conversion mechanism for electron perpendicular energy, both the thermal and the kinetic energy, is investigated by means of two-dimensional, full-particle simulations in an open system. It is shown that electron perpendicular heating is mainly due to the breaking of magnetic moment conservation in separatrix region because the charge separation generates intense variation of electric field within the electron Larmor radius. Meanwhile, electron perpendicular acceleration takes place manly due to the polarization drift term as well as the curvature drift term of E . u⊥ in the downstream near the X-point. The enhanced electric field due to the charge separation there results in a significant effect of the polarization drift term on the dissipation of magnetic energy within the ion inertia length in the downstream. Japan Society for the Promotion of Science (JSPS) Fellows 15J03758.

  15. 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.

  16. 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.

  17. 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.

  18. Extended exergy concept to facilitate designing and optimization of frequency-dependent direct energy conversion systems

    International Nuclear Information System (INIS)

    Wijewardane, S.; Goswami, Yogi

    2014-01-01

    Highlights: • Proved exergy method is not adequate to optimize frequency-dependent energy conversion. • Exergy concept is modified to facilitate the thermoeconomic optimization of photocell. • The exergy of arbitrary radiation is used for a practical purpose. • The utility of the concept is illustrated using pragmatic examples. - Abstract: Providing the radiation within the acceptable (responsive) frequency range(s) is a common method to increase the efficiency of the frequency-dependent energy conversion systems, such as photovoltaic and nano-scale rectenna. Appropriately designed auxiliary items such as spectrally selective thermal emitters, optical filters, and lenses are used for this purpose. However any energy conversion method that utilizes auxiliary components to increase the efficiency of a system has to justify the potential cost incurred by those auxiliary components through the economic gain emerging from the increased system efficiency. Therefore much effort should be devoted to design innovative systems, effectively integrating the auxiliary items and to optimize the system with economic considerations. Exergy is the widely used method to design and optimize conventional energy conversion systems. Although the exergy concept is used to analyze photovoltaic systems, it has not been used effectively to design and optimize such systems. In this manuscript, we present a modified exergy method in order to effectively design and economically optimize frequency-dependent energy conversion systems. Also, we illustrate the utility of this concept using examples of thermophotovoltaic, Photovoltaic/Thermal and concentrated solar photovoltaic

  19. 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.

  20. Research and development of utilization technology of solar thermal system for industrial and other use. Research and development of key technology (energy conversion on technology using chemical reactions); Sangyoyo nado solar system jitsuyoka gijutsu kaihatsu. Yoso gijutsu no kenkyu (kagaku energy henkan gijutsu no kenkyu)

    Energy Technology Data Exchange (ETDEWEB)

    Takita, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

    1994-12-01

    Described herein are the results of the FY1994 research program for energy conversion technology using chemical reactions by the aid of solar energy. The demonstration runs were conducted by a bench-scale unit, which was operated stably for 100h, to produce promising results. The catalyst exhibits stable performance, without showing a sign of deactivation. It is found that the heat pump system works well, without being interfered with accumulated by-products. A heat of approximately 2,100kcal/h is recovered. It is confirmed that steam of 150{degree}C and 200{degree}C is generated from hot water of 80{degree}C and 95{degree}C, respectively. The bench-scale runs show a thermal efficiency of around 10%, which is lower than the target level. However, the runs with hydrogen-occluding alloy attain a process thermal efficiency of 30%. The system in which solar collector and chemical heat pump units are combined is evaluated with respect to its economic efficiency and operability for its eventual commercialization. 6 figs., 2 tabs.

  1. The Cellulose Nanofibers for Optoelectronic Conversion and Energy Storage

    Directory of Open Access Journals (Sweden)

    Yongfeng Luo

    2014-01-01

    Full Text Available Cellulose widely exists in plant tissues. Due to the large pores between the cellulose units, the regular paper is nontransparent that cannot be used in the optoelectronic devices. But some chemical and physical methods such as 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO oxidation can be used to improve the pores scale between the cellulose units to reach nanometer level. The cellulose nanofibers (CNFs have good mechanical strength, flexibility, thermostability, and low thermal expansion. The paper made of these nanofibers represent a kind of novel nanostructured material with ultrahigh transparency, ultrahigh haze, conductivity, biodegradable, reproducible, low pollution, environment friendly and so on. These advantages make the novel nanostructured paper apply in the optoelectronic device possible, such as electronics energy storage devices. This kind of paper is considered most likely to replace traditional materials like plastics and glass, which is attracting widespread attention, and the related research has also been reported. The purpose of this paper is to review CNFs which are applied in optoelectronic conversion and energy storage.

  2. 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

  3. 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.

  4. Ions and electrons thermal effects on the fast-slow mode conversion process in a three components plasma

    International Nuclear Information System (INIS)

    Fidone, I.; Gomberoff, L.

    1977-07-01

    Fast-slow mode conversion in a deuterium plasma with a small amount of hydrogen impurity, for frequencies close to the two-ion hybrid frequency, is investigated. It is shown that while electron thermal effects tend to inhibit the wave conversion process, ion thermal effects tend to restore, qualitatively, the cold plasma properties, favouring therefore, the energy exchange between the two modes. The aforementioned effects are competitive for zetasub(o)sup(e)=1/nsub(parall).vsub(e)>=1. For zetasub(o)sup(e)<=1, electron thermal effects, in particular Landau damping, dominate over ion Larmor radius effects, drastically diminishing the wave conversion efficacy. For zetasub(o)sup(e)<<1, the coupling between the modes disappears altogether

  5. 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)

  6. 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

  7. 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%)

  8. 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.

  9. 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

  10. 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)

  11. 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.

  12. Solar energy thermally powered electrical generating system

    Science.gov (United States)

    Owens, William R. (Inventor)

    1989-01-01

    A thermally powered electrical generating system for use in a space vehicle is disclosed. The rate of storage in a thermal energy storage medium is controlled by varying the rate of generation and dissipation of electrical energy in a thermally powered electrical generating system which is powered from heat stored in the thermal energy storage medium without exceeding a maximum quantity of heat. A control system (10) varies the rate at which electrical energy is generated by the electrical generating system and the rate at which electrical energy is consumed by a variable parasitic electrical load to cause storage of an amount of thermal energy in the thermal energy storage system at the end of a period of insolation which is sufficient to satisfy the scheduled demand for electrical power to be generated during the next period of eclipse. The control system is based upon Kalman filter theory.

  13. 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. ...

  14. Thermal energy management process experiment

    Science.gov (United States)

    Ollendorf, S.

    1984-01-01

    The thermal energy management processes experiment (TEMP) will demonstrate that through the use of two-phase flow technology, thermal systems can be significantly enhanced by increasing heat transport capabilities at reduced power consumption while operating within narrow temperature limits. It has been noted that such phenomena as excess fluid puddling, priming, stratification, and surface tension effects all tend to mask the performance of two-phase flow systems in a 1-g field. The flight experiment approach would be to attack the experiment to an appropriate mounting surface with a 15 to 20 meter effective length and provide a heat input and output station in the form of heaters and a radiator. Using environmental data, the size, location, and orientation of the experiment can be optimized. The approach would be to provide a self-contained panel and mount it to the STEP through a frame. A small electronics package would be developed to interface with the STEP avionics for command and data handling. During the flight, heaters on the evaporator will be exercised to determine performance. Flight data will be evaluated against the ground tests to determine any anomalous behavior.

  15. Study of Aquifer Thermal Energy Storage

    Science.gov (United States)

    Okuyama, Masaaki; Umemiya, Hiromichi; Shibuya, Ikuko; Haga, Eiji

    Yamagata University 'Aquifer Thermal Energy Storage (ATES)' is the experimental system which has been running since 1982. From the results for along terms of experiments, we obtain many important knowledge. This paper presents the accomplishments for 16 years and the characteristics of thermal energy storage in thermal energy storage well. The conclusions show as follows. 1)In recent years, the thermal recovery factor of warm energy storage well becomes almost constant at about 60%. 2) The thermal recovery factor of cool energy storage well increases gradually and becomes at about 15%. 3) Since the ferric colloidal dam is formed in aquifer, thermal recovery factor increase year after year. 4) Back wash can remove clogging for ferric colloidal dam. 5) The apparent thermal diffusivity decrease gradually due to ferric colloidal dam.

  16. Azobenzene-functionalized carbon nanotubes as high-energy density solar thermal fuels.

    Science.gov (United States)

    Kolpak, Alexie M; Grossman, Jeffrey C

    2011-08-10

    Solar thermal fuels, which reversibly store solar energy in molecular bonds, are a tantalizing prospect for clean, renewable, and transportable energy conversion/storage. However, large-scale adoption requires enhanced energy storage capacity and thermal stability. Here we present a novel solar thermal fuel, composed of azobenzene-functionalized carbon nanotubes, with the volumetric energy density of Li-ion batteries. Our work also demonstrates that the inclusion of nanoscale templates is an effective strategy for design of highly cyclable, thermally stable, and energy-dense solar thermal fuels.

  17. Solar energy thermalization and storage device

    Science.gov (United States)

    McClelland, J.F.

    A passive solar thermalization and thermal energy storage assembly which is visually transparent is described. The assembly consists of two substantial parallel, transparent wall members mounted in a rectangular support frame to form a liquid-tight chamber. A semitransparent thermalization plate is located in the chamber, substantially paralled to and about equidistant from the transparent wall members to thermalize solar radiation which is stored in a transparent thermal energy storage liquid which fills the chamber. A number of the devices, as modules, can be stacked together to construct a visually transparent, thermal storage wall for passive solar-heated buildings.

  18. 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).

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. New device architecture of a thermoelectric energy conversion for recovering low-quality heat

    Science.gov (United States)

    Kim, Hoon; Park, Sung-Geun; Jung, Buyoung; Hwang, Junphil; Kim, Woochul

    2014-03-01

    Low-quality heat is generally discarded for economic reasons; a low-cost energy conversion device considering price per watt, /W, is required to recover this waste heat. Thin-film based thermoelectric devices could be a superior alternative for this purpose, based on their low material consumption; however, power generated in conventional thermoelectric device architecture is negligible due to the small temperature drop across the thin film. To overcome this challenge, we propose new device architecture, and demonstrate approximately 60 Kelvin temperature differences using a thick polymer nanocomposite. The temperature differences were achieved by separating the thermal path from the electrical path; whereas in conventional device architecture, both electrical charges and thermal energy share same path. We also applied this device to harvest body heat and confirmed its usability as an energy conversion device for recovering low-quality heat.

  7. 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...

  8. 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

  9. 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...

  10. Study on thermal electric conversion system for FBR plant. Investigation for effective EVST waste heat recovery system

    International Nuclear Information System (INIS)

    Maekawa, Isamu; Kurata, Chikatoshi

    2004-02-01

    Recently, it has been important to reuse discharged heat energy from present nuclear plant, especially from sodium cooled FBR, which are typical high temperature system, in the view of reduction of environmental burden and improvement of heat efficiency for plant. The thermal electric conversion system can work only the temperature difference and has been applied to the limited fields such as space or military, however, that results show good merits for reliability, maintenance free, and so on. Recently, the development of new thermal electric conversion elements has made remarkable progress. In this study, for the effective utilization of waste heat from Monju', the prototype plant of FBR, we made an investigation of electric power generating system maintaining the cooling faculty by applying the thermal electric conversion system to sodium cooling line of EVST. Using the new type iron based thermal electric conversion elements, which are plentiful, economical and good for environmental harmonization, we have calculated the amount of heat exchange and power generation from sodium cooling line of EVST, and have investigated the module sizing, cost and subject to be settled. The results were , (1)The amount of power generation from sodium cooling line of EVST is smaller about one figure than motive power of sodium cooler fan. However, if Seebeck coefficient and heat conductivity of iron based thermal electric conversion elements shall be improved, power from sodium cooling line shall be able to cover the motive power. (2) The amount of heat released from sodium cooling line after the installation of thermal electric conversion module covers the necessity to maintain the sodium cooling faculty. (3) In case of the installation of module to the sodium cooler, it should be reconstructed because of tube arrangement modification. In case of the installation of module to the sodium connecting line, air ventilation system is needed to suppress the room temperature. (4) As

  11. 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

  12. 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)

  13. 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.

  14. 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.

  15. Micro rectennas: Brownian ratchets for thermal-energy harvesting

    International Nuclear Information System (INIS)

    Pan, Y.; Powell, C. V.; Balocco, C.; Song, A. M.

    2014-01-01

    We experimentally demonstrated the operation of a rectenna for harvesting thermal (blackbody) radiation and converting it into dc electric power. The device integrates an ultrafast rectifier, the self-switching nanodiode, with a wideband log-periodic spiral microantenna. The radiation from the thermal source drives the rectenna out of thermal equilibrium, permitting the rectification of the excess thermal fluctuations from the antenna. The power conversion efficiency increases with the source temperatures up to 0.02% at 973 K. The low efficiency is attributed mainly to the impedance mismatch between antenna and rectifier, and partially to the large field of view of the antenna. Our device not only opens a potential solution for harvesting thermal energy but also provides a platform for experimenting with Brownian ratchets

  16. Micro rectennas: Brownian ratchets for thermal-energy harvesting

    Science.gov (United States)

    Pan, Y.; Powell, C. V.; Song, A. M.; Balocco, C.

    2014-12-01

    We experimentally demonstrated the operation of a rectenna for harvesting thermal (blackbody) radiation and converting it into dc electric power. The device integrates an ultrafast rectifier, the self-switching nanodiode, with a wideband log-periodic spiral microantenna. The radiation from the thermal source drives the rectenna out of thermal equilibrium, permitting the rectification of the excess thermal fluctuations from the antenna. The power conversion efficiency increases with the source temperatures up to 0.02% at 973 K. The low efficiency is attributed mainly to the impedance mismatch between antenna and rectifier, and partially to the large field of view of the antenna. Our device not only opens a potential solution for harvesting thermal energy but also provides a platform for experimenting with Brownian ratchets.

  17. Micro rectennas: Brownian ratchets for thermal-energy harvesting

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Y.; Powell, C. V.; Balocco, C., E-mail: claudio.balocco@durham.ac.uk [School of Engineering and Computing Sciences, Durham University, Durham DH1 3LE (United Kingdom); Song, A. M. [School of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL (United Kingdom)

    2014-12-22

    We experimentally demonstrated the operation of a rectenna for harvesting thermal (blackbody) radiation and converting it into dc electric power. The device integrates an ultrafast rectifier, the self-switching nanodiode, with a wideband log-periodic spiral microantenna. The radiation from the thermal source drives the rectenna out of thermal equilibrium, permitting the rectification of the excess thermal fluctuations from the antenna. The power conversion efficiency increases with the source temperatures up to 0.02% at 973 K. The low efficiency is attributed mainly to the impedance mismatch between antenna and rectifier, and partially to the large field of view of the antenna. Our device not only opens a potential solution for harvesting thermal energy but also provides a platform for experimenting with Brownian ratchets.

  18. Application of nanomaterials in solar thermal energy storage

    Science.gov (United States)

    Shamshirgaran, Seyed Reza; Khalaji Assadi, Morteza; Viswanatha Sharma, Korada

    2018-06-01

    Solar thermal conversion technology harvests the sun's energy, rather than fossil fuels, to generate low-cost, low/zero-emission energy in the form of heating, cooling or electrical form for residential, commercial, and industrial sectors. The advent of nanofluids and nanocomposites or phase change materials, is a new field of study which is adapted to enhance the efficiency of solar collectors. The concepts of thermal energy storage technologies are investigated and the role of nanomaterials in energy conversion is discussed. This review revealed that although the exploitation of nanomaterials will boost the performance of solar collectors almost in all cases, this would be accompanied by certain challenges such as production cost, instability, agglomeration and erosion. Earlier studies have dealt with the enhancement of thermal conductivity and heat capacity; however, less attention has been given to the facing challenges. Moreover, no exact criteria can be found for the selection of appropriate nanomaterials and their properties for a specific application. In most research studies, the nanoparticles' material and properties have not been selected based on estimated values so that all the aspects of desired application could be considered simultaneously. The wide spread use of nanomaterials can lead to cost effective solutions as well. Therefore, it seems there should be a sense of techno-economic optimization in exploiting nanomaterials for solar thermal energy storage applications. The optimization should cover the key parameters, particularly nanoparticle type, size, loading and shape which depends on the sort of application and also dispersion technology.

  19. Application of nanomaterials in solar thermal energy storage

    Science.gov (United States)

    Shamshirgaran, Seyed Reza; Khalaji Assadi, Morteza; Viswanatha Sharma, Korada

    2017-12-01

    Solar thermal conversion technology harvests the sun's energy, rather than fossil fuels, to generate low-cost, low/zero-emission energy in the form of heating, cooling or electrical form for residential, commercial, and industrial sectors. The advent of nanofluids and nanocomposites or phase change materials, is a new field of study which is adapted to enhance the efficiency of solar collectors. The concepts of thermal energy storage technologies are investigated and the role of nanomaterials in energy conversion is discussed. This review revealed that although the exploitation of nanomaterials will boost the performance of solar collectors almost in all cases, this would be accompanied by certain challenges such as production cost, instability, agglomeration and erosion. Earlier studies have dealt with the enhancement of thermal conductivity and heat capacity; however, less attention has been given to the facing challenges. Moreover, no exact criteria can be found for the selection of appropriate nanomaterials and their properties for a specific application. In most research studies, the nanoparticles' material and properties have not been selected based on estimated values so that all the aspects of desired application could be considered simultaneously. The wide spread use of nanomaterials can lead to cost effective solutions as well. Therefore, it seems there should be a sense of techno-economic optimization in exploiting nanomaterials for solar thermal energy storage applications. The optimization should cover the key parameters, particularly nanoparticle type, size, loading and shape which depends on the sort of application and also dispersion technology.

  20. Thermal energy storage apparatus, controllers and thermal energy storage control methods

    Science.gov (United States)

    Hammerstrom, Donald J.

    2016-05-03

    Thermal energy storage apparatus, controllers and thermal energy storage control methods are described. According to one aspect, a thermal energy storage apparatus controller includes processing circuitry configured to access first information which is indicative of surpluses and deficiencies of electrical energy upon an electrical power system at a plurality of moments in time, access second information which is indicative of temperature of a thermal energy storage medium at a plurality of moments in time, and use the first and second information to control an amount of electrical energy which is utilized by a heating element to heat the thermal energy storage medium at a plurality of moments in time.

  1. 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.

  2. 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

  3. Energy conversion and dissipation at dipolarization fronts: Theory, modeling and MMS observations

    Science.gov (United States)

    Sitnov, M. I.; Motoba, T.; Merkin, V. G.; Ohtani, S.; Cohen, I. J.; Mauk, B.; Vines, S. K.; Anderson, B. J.; Moore, T. E.; Torbert, R. B.; Giles, B. L.; Burch, J. L.

    2017-12-01

    Magnetic reconnection is one of the most important energy conversion mechanisms in space plasmas. In the classical picture it converts the energy of antiparallel magnetic fields into the kinetic and thermal energy of accelerated plasma particles in reconnection exhausts. It also involves energy dissipation near the X-line. This classical picture may be substantially modified in real space plasma configurations, such as the dayside magnetopause and the magnetotail. In particular, in the magnetotail the flows of accelerated particles may be strongly asymmetric along the tail with the domination of earthward flows. At the same time, strong energy conversion and even dissipation may occur away from the X-line, in particular, at dipolarization fronts. Here we present a theoretical picture of spontaneous magnetotail reconnection based on 3-D PIC simulations with the focus on plasma bulk flows, energy conversion and dissipation. This picture is compared with some observations from the MMS tail season. An important finding from these observations is that dipolarizations fronts may not only be regions of the total energy conversion with jE>0, but they may also be the sites of energy dissipation, both positive (jE'>0, E' is the electric field E in the system moving with one of the plasma species) and negative (jE'braking).

  4. Energy Storage Thermal Safety | Transportation Research | NREL

    Science.gov (United States)

    reaction/thermal runaway, internal short circuit, and electrical/chemical/thermal network models are used contributions to the U.S. Department of Energy's Computer-Aided Engineering of Batteries (CAEBAT) project Li-ion battery geometries. Chemical components in Li-ion batteries become thermally unstable when

  5. 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.

  6. 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.

  7. 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.

  8. Energy-efficient biogas reforming process to produce syngas: The enhanced methane conversion by O_2

    International Nuclear Information System (INIS)

    Chen, Xuejing; Jiang, Jianguo; Li, Kaimin; Tian, Sicong; Yan, Feng

    2017-01-01

    Highlights: • The effect of O_2 content from 0 to 15% on Ni/SiO_2 are studied for biogas reforming. • The presence of O_2 in biogas improves CH_4 conversion and stability of biogas reforming. • An obvious carbon-resistance effect is observed due to the carbon gasification effect of O_2 in biogas. • The presence of O_2 in biogas greatly helps inhibit the catalyst sintering. - Abstract: We report an energy-efficient biogas reforming process with high and stable methane conversions by O_2 presence. During this biogas reforming process, the effects of various O_2 concentrations in biogas on initial conversions and stability at various temperatures on a Ni/SiO_2 catalyst were detailed investigated. In addition, theoretical energy consumption and conversions were calculated based on the Gibbs energy minimization method to compare with experimental results. Carbon formation and sintering during the reforming process were characterized by thermal gravity analysis, the Brunauer-Emmett-Teller method, X-ray diffraction, and high-resolution transmission electron microscopy to investigate the feasibility of applying this process to an inexpensive nickel catalyst. The results showed that 5% O_2 in biogas improved the CH_4 conversion and stability of biogas reforming. The enhancement of stability was attributed to the inhibited sintering, our first finding, and the reduced carbon deposition at the same time, which sustained a stable conversion of CH_4, and proved the applicability of base Ni catalyst to this process. Higher O_2 concentrations (⩾10%) in biogas resulted in severe decrease in CO_2 conversion and greater H_2O productivity. Our proposed biogas reforming process, with a high and stable conversion of CH_4, reduced energy input, and the applicability to inexpensive base metal catalyst, offers a good choice for biogas reforming with low O_2 concentrations (⩽5%) to produce syngas with high energy efficiency.

  9. 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.

  10. Potential energy savings and thermal comfort

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev; Rudbeck, Claus Christian; Schultz, Jørgen Munthe

    1996-01-01

    The simulation results on the energy saving potential and influence on indoor thermal comfort by replacement of common windows with aerogel windows as well as commercial low-energy windows are described and analysed.......The simulation results on the energy saving potential and influence on indoor thermal comfort by replacement of common windows with aerogel windows as well as commercial low-energy windows are described and analysed....

  11. 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

  12. 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.

  13. 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.

  14. Concrete thermal energy storage for steam generation

    DEFF Research Database (Denmark)

    Singh, Shobhana; Sørensen, Kim

    2017-01-01

    Establishing enhancement methods to develop cost-effective thermal energy storage technology requires a detailed analysis. In this paper, a numerical investigation of the concrete based thermal energy storage system is carried out. The storage system consists of a heat transfer fluid flowing inside...

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Solar thermal energy as a topic in secondary mathematics classrooms

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, A.; Brinkmann, K. [EnviPro Environmental Process Engineering Prof. Dr. Klaus Brinkmann, Iserlohn (Germany)

    2004-07-01

    One of the most effective methods to achieve a sustainable change of our momentary existing power supply system to a system mainly based on renewable energy conversion is the education of our children. For this purpose the compulsory school subject mathematics appears to be suitable. In order to promote renewable energy issues in mathematics classrooms, the authors have developed a special didactical concept to open this field for students, as well as for their teachers. The aim of this paper is to present firstly an overview of our concept and secondly examples of problems to the special topic of solar thermal energy, developed on the basis of our concept. (orig.)

  2. Thermal energy systems design and analysis

    CERN Document Server

    Penoncello, Steven G

    2015-01-01

    IntroductionThermal Energy Systems Design and AnalysisSoftwareThermal Energy System TopicsUnits and Unit SystemsThermophysical PropertiesEngineering DesignEngineering EconomicsIntroductionCommon Engineering Economics NomenclatureEconomic Analysis Tool: The Cash Flow DiagramTime Value of MoneyTime Value of Money ExamplesUsing Software to Calculate Interest FactorsEconomic Decision MakingDepreciation and TaxesProblemsAnalysis of Thermal Energy SystemsIntroductionNomenclatureThermophysical Properties of SubstancesSuggested Thermal Energy Systems Analysis ProcedureConserved and Balanced QuantitiesConservation of MassConservation of Energy (The First Law of Thermodynamics)Entropy Balance (The Second Law of Thermodynamics)Exergy Balance: The Combined LawEnergy and Exergy Analysis of Thermal Energy CyclesDetailed Analysis of Thermal Energy CyclesProblemsFluid Transport in Thermal Energy SystemsIntroductionPiping and Tubing StandardsFluid Flow FundamentalsValves and FittingsDesign and Analysis of Pipe NetworksEconomi...

  3. 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

  4. TECHNOLOGICAL AND ENVIRONMENTAL PROBLEMS CONNECTED WITH THERMAL CONVERSION OF SEWAGE SLUDGE

    Directory of Open Access Journals (Sweden)

    Alina Żogała

    2016-02-01

    Full Text Available Overview of the most common technological and environmental problems connected with thermal conversion of sewage sludge was presented in the article. Such issues as the influence of content of moisture and mineral matter on fuel properties of sludge, problem of emission of pollutants, problem of management of solid residue, risk of corrosion, were described. Besides, consolidated characteristic of the most important methods of thermal conversion of sewage sludge, with their advantages and disadvantages, was presented in the paper.

  5. 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

  6. Hybrid chromophore/template nanostructures: a customizable platform material for solar energy storage and conversion.

    Science.gov (United States)

    Kolpak, Alexie M; Grossman, Jeffrey C

    2013-01-21

    Challenges with cost, cyclability, and/or low energy density have largely prevented the development of solar thermal fuels, a potentially attractive alternative energy technology based on molecules that can capture and store solar energy as latent heat in a closed cycle. In this paper, we present a set of novel hybrid photoisomer/template solar thermal fuels that can potentially circumvent these challenges. Using first-principles computations, we demonstrate that these fuels, composed of organic photoisomers bound to inexpensive carbon-based templates, can reversibly store solar energy at densities comparable to Li-ion batteries. Furthermore, we show that variation of the template material in combination with the photoisomer can be used to optimize many of the key performance metrics of the fuel-i.e., the energy density, the storage lifetime, the temperature of the output heat, and the efficiency of the solar-to-heat conversion. Our work suggests that the solar thermal fuels concept can be translated into a practical and highly customizable energy storage and conversion technology.

  7. 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)

  8. 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.

  9. Thermal energy accumulators. A bibliographical study

    International Nuclear Information System (INIS)

    Charlety, Paul

    1971-01-01

    Energy storage is a challenge, notably for spacecraft, submarines and non-polluting automotive vehicles. After a comparison of mass energies of different principles of energy accumulation (magnetic, electrostatic, solid elasticity, kinetic energy, gaseous elasticity, electro-chemistry, sensitive heat, freezing heat, fuels, radioactivity, nuclear fission or fusion, mass energy), the author discusses the choice of thermal storage, presents the main bodies used for thermal energy accumulation (molten salts such as lithium hydride or lithium salt eutectics, or other compounds such as alumina, paraffins), and gives an overview of the main theoretical problems [fr

  10. SYNTHESIS, THERMAL STUDIES AND CONVERSION DEGREE OF DIMETHACRYLATE POLYMERS USING NEW NON-TOXIC COINITIATORS

    Directory of Open Access Journals (Sweden)

    Rafael Turra Alarcon

    Full Text Available The aim of this paper is to replace toxic coinitiators (tertiary amines by non-toxic compounds such as glycerol and inositol (polyalcohol in dimethacrylate resins. For this purpose, mid infrared spectroscopy (MIR was used to calculate the monomers' degree of conversion (%DC; as well as simultaneous Thermogravimetric Analysis – Differential Thermal Analysis (TGA-DTA and Differential Scanning Calorimetry (DSC were conducted to evaluate thermal stability, degradation steps, and thermal events. The use of different initiator systems did not modify the thermal events or the thermal stability of each of the dimethacrylate resins. Results show a substitution of system 2 (toxicity by system 3 (low toxicity, which had a good conversion velocity and total conversion in some monomers, is plausible.

  11. 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.

  12. Phase Change Materials for Thermal Energy Storage

    OpenAIRE

    Stiebra, L; Cabulis, U; Knite, M

    2014-01-01

    Phase change materials (PCMs) for thermal energy storage (TES) have become an important subject of research in recent years. Using PCMs for thermal energy storage provides a solution to increase the efficiency of the storage and use of energy in many domestic and industrial sectors. Phase change TES systems offer a number of advantages over other systems (e.g. chemical storage systems): particularly small temperature distance between the storage and retrieval cycles, small unit sizes and lo...

  13. Thermal performance and heat transport in aquifer thermal energy storage

    Science.gov (United States)

    Sommer, W. T.; Doornenbal, P. J.; Drijver, B. C.; van Gaans, P. F. M.; Leusbrock, I.; Grotenhuis, J. T. C.; Rijnaarts, H. H. M.

    2014-01-01

    Aquifer thermal energy storage (ATES) is used for seasonal storage of large quantities of thermal energy. Due to the increasing demand for sustainable energy, the number of ATES systems has increased rapidly, which has raised questions on the effect of ATES systems on their surroundings as well as their thermal performance. Furthermore, the increasing density of systems generates concern regarding thermal interference between the wells of one system and between neighboring systems. An assessment is made of (1) the thermal storage performance, and (2) the heat transport around the wells of an existing ATES system in the Netherlands. Reconstruction of flow rates and injection and extraction temperatures from hourly logs of operational data from 2005 to 2012 show that the average thermal recovery is 82 % for cold storage and 68 % for heat storage. Subsurface heat transport is monitored using distributed temperature sensing. Although the measurements reveal unequal distribution of flow rate over different parts of the well screen and preferential flow due to aquifer heterogeneity, sufficient well spacing has avoided thermal interference. However, oversizing of well spacing may limit the number of systems that can be realized in an area and lower the potential of ATES.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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

  1. Preparation of {sup 114m}In low energy conversion electron sources

    Energy Technology Data Exchange (ETDEWEB)

    Wrede, C., E-mail: wrede@uw.ed [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Filippone, B.W. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125 (United States); Garcia, A.; Harper, G.C. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Lassell, S. [Department of Nuclear Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Liu, J. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125 (United States); Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Mendenhall, M.P. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125 (United States); Palmer, A.S.C. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Pattie, R.W. [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695 (United States); Will, D.I. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Young, A.R. [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2011-05-15

    Highlights: {yields} Controlled ion implantation of In-113 into thin Al substrate. {yields} Production of In-114m (half life = 50 days) by neutron irradiation. {yields} Use of In-114m as a source of electron lines and continuum for calibrations. {yields} Source reactivation by short neutron irradiation. -- Abstract: The preparation of {sup 114m}In sources of conversion electrons in the energy range 162-190 keV and {beta} continuum with a 1989 keV endpoint via ion implantation of {sup 113}In into Al substrates and subsequent irradiation by thermal and epi-thermal neutrons in a nuclear reactor is described.

  2. Preparation of 114mIn low energy conversion electron sources

    International Nuclear Information System (INIS)

    Wrede, C.; Filippone, B.W.; Garcia, A.; Harper, G.C.; Lassell, S.; Liu, J.; Mendenhall, M.P.; Palmer, A.S.C.; Pattie, R.W.; Will, D.I.; Young, A.R.

    2011-01-01

    Highlights: → Controlled ion implantation of In-113 into thin Al substrate. → Production of In-114m (half life = 50 days) by neutron irradiation. → Use of In-114m as a source of electron lines and continuum for calibrations. → Source reactivation by short neutron irradiation. -- Abstract: The preparation of 114m In sources of conversion electrons in the energy range 162-190 keV and β continuum with a 1989 keV endpoint via ion implantation of 113 In into Al substrates and subsequent irradiation by thermal and epi-thermal neutrons in a nuclear reactor is described.

  3. 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

  4. Adaptability of Brayton cycle conversion systems to fast, epithermal and thermal spectrum space nuclear reactors

    International Nuclear Information System (INIS)

    Tilliette, Z.P.

    1988-01-01

    The two French Government Agencies C.N.E.S. (Centre National d'Etudes Spatiales) and C.E.A. (Commissariat a l'Energie Atomique) are carrying out joint preliminary studies on space nuclear power systems for future ARIANE 5 launch vehicle applications. The Brayton cycle is the reference conversion system, whether the heat source is a liquid metal-cooled (NaK, Na or Li) reactor or a gas-cooled direct cycle concept. The search for an adequate utilization of this energy conversion means has prompted additional evaluations featuring the definition of satisfactory cycle conditions for these various kinds of reactor concepts. In addition to firstly studied fast and epithermal spectrum ones, thermal spectrum reactors can offer an opportunity of bringing out some distinctive features of the Brayton cycle, in particular for the temperature conditioning of the efficient metal hydrides (ZrH, Li/sub 7/H) moderators. One of the purposes of the paper is to confirm the potential of long lifetime ZrH moderated reactors associated with a gas cycle and to assess the thermodynamical consequences for both Nak(Na)-cooled or gas-cooled nuclear heat sources. This investigation is complemented by the definition of appropriate reactor arrangements which could be presented on a further occasion

  5. Photonic design for efficient solid state energy conversion

    Science.gov (United States)

    Agrawal, Mukul

    The efficiency of conversion between electrical and photonic energy in optoelectronic devices such as light-emitting diodes, photodetectors and solar cells is strongly affected by the photonic modes supported by the device structure. In this thesis, we show how tuning of the local photon density of states in subwavelength structures can be used to optimize device performance. The first part of the thesis is focused on organic light emitting diodes (OLEDs), a candidate technology for next-generation displays and solid-state lighting. An important unsolved problem in OLEDs is to ensure that a significant fraction of photons emitted by the organic emissive layer couple out of the device structure instead of remaining trapped in the device. It is shown using modeling and experiments that optimized non-periodic dielectric multilayer stacks can significantly increase the photon outcoupling while maintaining display quality brightness uniformity over the viewing cone. In the second part, we discuss the theoretical limits to broadband light harvesting in photovoltaic cells. First, it is shown that the extent to which one-dimensional optical cavities can be used to enhance light absorption over a broad spectral range is limited by the requirement that the cavity mirrors have a causal response. This result is used as a guide to design practical dielectric structures that enhance light harvesting in planar thin-film organic solar cells. Finally, we consider the enhancement of optical absorption in two- and three-dimensional structures in which incident light is scattered into quasi-trapped modes for more effective utilization of solar radiation. It is shown that there is an upper bound to the degree to which optical absorption can be enhanced that is identical to the limit found in the geometric optics regime. Rigorous optical simulations are used to show that an optical structure consisting of a two-dimensional array of inverted pyramids comes close to this limit. Before

  6. 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

  7. Thermoelectric conversion efficiency in IV-VI semiconductors with reduced thermal conductivity

    Directory of Open Access Journals (Sweden)

    Akihiro Ishida

    2015-10-01

    Full Text Available Mid-temperature thermoelectric conversion efficiencies of the IV-VI materials were calculated under the Boltzmann transport theory of carriers, taking the Seebeck, Peltier, and Thomson effects into account. The conversion efficiency was discussed with respect to the lattice thermal conductivity, keeping other parameters such as Seebeck coefficient and electrical conductivity to the same values. If room temperature lattice thermal conductivity is decreased up to 0.5W/mK, the conversion efficiency of a PbS based material becomes as high as 15% with the temperature difference of 500K between 800K and 300K.

  8. 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.

  9. Fe-catalyzed thermal conversion of sodium lignosulfonate to graphene

    Science.gov (United States)

    Sung Phil Mun; Zhiyong Cai; Jilei Zhang

    2013-01-01

    Sodium lignosulfonate (LS) from sulfite pulping processing was used as a carbon source to synthesize graphene. LS was mixed with Fe nanoparticles (FeNPs) as a catalyst and thermally treated at 1000 °C for 1 h. The Raman spectrum and X-ray diffraction pattern suggested that graphene sheets were formed in LS thermally treated with FeNPs (Fe-HTLS). Scanning...

  10. Thermodynamic analysis of energy conversion and transfer in hybrid system consisting of wind turbine and advanced adiabatic compressed air energy storage

    International Nuclear Information System (INIS)

    Zhang, Yuan; Yang, Ke; Li, Xuemei; Xu, Jianzhong

    2014-01-01

    A simulation model consisting of wind speed, wind turbine and AA-CAES (advanced adiabatic compressed air energy storage) system is developed in this paper, and thermodynamic analysis on energy conversion and transfer in hybrid system is carried out. The impacts of stable wind speed and unstable wind speed on the hybrid system are analyzed and compared from the viewpoint of energy conversion and system efficiency. Besides, energy conversion relationship between wind turbine and AA-CAES system is investigated on the basis of process analysis. The results show that there are several different forms of energy in hybrid system, which have distinct conversion relationship. As to wind turbine, power coefficient determines wind energy utilization efficiency, and in AA-CAES system, it is compressor efficiency that mainly affects energy conversion efficiencies of other components. The strength and fluctuation of wind speed have a direct impact on energy conversion efficiencies of components of hybrid system, and within proper wind speed scope, the maximum of system efficiency could be expected. - Highlights: • A hybrid system consisting of wind, wind turbine and AA-CAES system is established. • Energy conversion in hybrid system with stable and unstable wind speed is analyzed. • Maximum efficiency of hybrid system can be reached within proper wind speed scope. • Thermal energy change in hybrid system is more sensitive to wind speed change. • Compressor efficiency can affect other efficiencies in AA-CAES system

  11. Enhanced Mode Conversion of Thermally Emitted Electron Bernstein Waves (EBW)to Extraordinary Mode

    International Nuclear Information System (INIS)

    Jones, B.; Efthimion, P.C.; Taylor, G.; Munsat, T.; Wilson, J.R.; Hosea, J.C.; Kaita, R.; Majeski, R.; Maingi, R.; Shiraiwa, S.; Spaleta, J.

    2002-01-01

    In the CDX-U spherical torus, approximately 100% conversion of thermal EBWs to X-mode has been observed by controlling the electron density scale length (Ln) in the conversion region with a local limiter outside the last closed flux surface. The radiation temperature profile agrees with Thomson scattering electron temperature data. Results are consistent with theoretical calculations of conversion efficiency using measured Ln. By reciprocity of the conversion process, prospects for efficient coupling in EBW heating and current drive scenarios are strongly supported

  12. Enhanced Mode Conversion of Thermally Emitted Electron Bernstein Waves (EBW)to Extraordinary Mode; TOPICAL

    International Nuclear Information System (INIS)

    B. Jones; P.C. Efthimion; G. Taylor; T. Munsat; J.R. Wilson; J.C. Hosea; R. Kaita; R. Majeski; R. Maingi; S. Shiraiwa; J. Spaleta

    2002-01-01

    In the CDX-U spherical torus, approximately 100% conversion of thermal EBWs to X-mode has been observed by controlling the electron density scale length (Ln) in the conversion region with a local limiter outside the last closed flux surface. The radiation temperature profile agrees with Thomson scattering electron temperature data. Results are consistent with theoretical calculations of conversion efficiency using measured Ln. By reciprocity of the conversion process, prospects for efficient coupling in EBW heating and current drive scenarios are strongly supported

  13. 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...

  14. 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.

  15. 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.

  16. Thermal Comfort and Strategies for Energy Conservation.

    Science.gov (United States)

    Rohles, Frederick H., Jr.

    1981-01-01

    Discusses studies in thermal comfort which served as the basis for the comfort standard. Examines seven variables in the human response to the thermal environment in terms of the ways in which they can be modified to conserve energy. (Author/MK)

  17. Energy efficient thermal management of data centers

    CERN Document Server

    Kumar, Pramod

    2012-01-01

    Energy Efficient Thermal Management of Data Centers examines energy flow in today's data centers. Particular focus is given to the state-of-the-art thermal management and thermal design approaches now being implemented across the multiple length scales involved. The impact of future trends in information technology hardware, and emerging software paradigms such as cloud computing and virtualization, on thermal management are also addressed. The book explores computational and experimental characterization approaches for determining temperature and air flow patterns within data centers. Thermodynamic analyses using the second law to improve energy efficiency are introduced and used in proposing improvements in cooling methodologies. Reduced-order modeling and robust multi-objective design of next generation data centers are discussed. This book also: Provides in-depth treatment of energy efficiency ideas based on  fundamental heat transfer, fluid mechanics, thermodynamics, controls, and computer science Focus...

  18. Advances in solar thermal energy in Uruguay

    International Nuclear Information System (INIS)

    Franco Noceto, P.

    2012-01-01

    This article is about the law 18585 which declared de solar thermal energy as national interest. This law establishes the obligation to incorporate solar heating systems in health care centers, hotels and sports clubs.

  19. 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.

  20. Enhancing radiative energy transfer through thermal extraction

    Science.gov (United States)

    Tan, Yixuan; Liu, Baoan; Shen, Sheng; Yu, Zongfu

    2016-06-01

    Thermal radiation plays an increasingly important role in many emerging energy technologies, such as thermophotovoltaics, passive radiative cooling and wearable cooling clothes [1]. One of the fundamental constraints in thermal radiation is the Stefan-Boltzmann law, which limits the maximum power of far-field radiation to P0 = σT4S, where σ is the Boltzmann constant, S and T are the area and the temperature of the emitter, respectively (Fig. 1a). In order to overcome this limit, it has been shown that near-field radiations could have an energy density that is orders of magnitude greater than the Stefan-Boltzmann law [2-7]. Unfortunately, such near-field radiation transfer is spatially confined and cannot carry radiative heat to the far field. Recently, a new concept of thermal extraction was proposed [8] to enhance far-field thermal emission, which, conceptually, operates on a principle similar to oil immersion lenses and light extraction in light-emitting diodes using solid immersion lens to increase light output [62].Thermal extraction allows a blackbody to radiate more energy to the far field than the apparent limit of the Stefan-Boltzmann law without breaking the second law of thermodynamics. Thermal extraction works by using a specially designed thermal extractor to convert and guide the near-field energy to the far field, as shown in Fig. 1b. The same blackbody as shown in Fig. 1a is placed closely below the thermal extractor with a spacing smaller than the thermal wavelength. The near-field coupling transfers radiative energy with a density greater than σT4. The thermal extractor, made from transparent and high-index or structured materials, does not emit or absorb any radiation. It transforms the near-field energy and sends it toward the far field. As a result, the total amount of far-field radiative heat dissipated by the same blackbody is greatly enhanced above SσT4, where S is the area of the emitter. This paper will review the progress in thermal

  1. 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)

  2. Graphene Thermal Properties: Applications in Thermal Management and Energy Storage

    Directory of Open Access Journals (Sweden)

    Jackie D. Renteria

    2014-11-01

    Full Text Available We review the thermal properties of graphene, few-layer graphene and graphene nanoribbons, and discuss practical applications of graphene in thermal management and energy storage. The first part of the review describes the state-of-the-art in the graphene thermal field focusing on recently reported experimental and theoretical data for heat conduction in graphene and graphene nanoribbons. The effects of the sample size, shape, quality, strain distribution, isotope composition, and point-defect concentration are included in the summary. The second part of the review outlines thermal properties of graphene-enhanced phase change materials used in energy storage. It is shown that the use of liquid-phase-exfoliated graphene as filler material in phase change materials is promising for thermal management of high-power-density battery parks. The reported experimental and modeling results indicate that graphene has the potential to outperform metal nanoparticles, carbon nanotubes, and other carbon allotropes as filler in thermal management materials.

  3. Graphene-based Electrochemical Energy Conversion and Storage: Fuel cells, Supercapacitors and Lithium Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Junbo; Shao, Yuyan; Ellis, Michael A.; Moore, Robert; Yi, Baolian

    2011-09-14

    Graphene has attracted extensive research interest due to its strictly 2-dimensional (2D) structure, which results in its unique electronic, thermal, mechanical, and chemical properties and potential technical applications. These remarkable characteristics of graphene, along with the inherent benefits of a carbon material, make it a promising candidate for application in electrochemical energy devices. This article reviews the methods of graphene preparation, introduces the unique electrochemical behavior of graphene, and summarizes the recent research and development on graphene-based fuel cells, supercapacitors and lithium ion batteries. In addition, promising areas are identified for the future development of graphene-based materials in electrochemical energy conversion and storage systems.

  4. 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.

  5. Innovative oxide materials for electrochemical energy conversion and oxygen separation

    Science.gov (United States)

    Belousov, V. V.

    2017-10-01

    Ion-conducting solid metal oxides are widely used in high-temperature electrochemical devices for energy conversion and oxygen separation. However, liquid metal oxides possessing unique electrochemical properties still remain of limited use. The review demonstrates the potential for practical applications of molten oxides. The transport properties of molten oxide materials are discussed. The emphasis is placed on the chemical diffusion of oxygen in the molten oxide membrane materials for electrochemical energy conversion and oxygen separation. The thermodynamics of these materials is considered. The dynamic polymer chain model developed to describe the oxygen ion transport in molten oxides is discussed. Prospects for further research into molten oxide materials are outlined. The bibliography includes 145 references.

  6. Covalent Organic Framework Electrocatalysts for Clean Energy Conversion.

    Science.gov (United States)

    Lin, Chun-Yu; Zhang, Detao; Zhao, Zhenghang; Xia, Zhenhai

    2018-02-01

    Covalent organic frameworks (COFs) are promising for catalysis, sensing, gas storage, adsorption, optoelectricity, etc. owning to the unprecedented combination of large surface area, high crystallinity, tunable pore size, and unique molecular architecture. Although COFs are in their initial research stage, progress has been made in the design and synthesis of COF-based electrocatalysis for the oxygen reduction reaction, oxygen evolution reaction, hydrogen evolution reaction, and CO 2 reduction in energy conversion and fuel generation. Design principles are also established for some of the COF materials toward rational design and rapid screening of the best electrocatalysts for a specific application. Herein, the recent advances in the design and synthesis of COF-based catalysts for clean energy conversion and storage are presented. Future research directions and perspectives are also being discussed for the development of efficient COF-based electrocatalysts. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Effect of linear temperature dependence of thermoelectric properties on energy conversion efficiency

    International Nuclear Information System (INIS)

    Yamashita, Osamu

    2008-01-01

    New thermal rate equations were developed by taking the temperature dependences of the electrical resistivity ρ and thermal conductivity κ of the thermoelectric (TE) materials into the thermal rate equations on the assumption that they vary linearly with temperature T. The relative energy conversion efficiency η/η 0 for a single TE element was formulated by approximate analysis, where η and η 0 are the energy conversion efficiencies derived from the new and conventional thermal rate equations, respectively. Applying it to Si-Ge alloys, the temperature dependence of ρ is stronger than that of κ, so the former has a more significant effect on η/η 0 than the latter. However, the degree of contribution from both of them to η/η 0 was a little lower than 1% at the temperature difference ΔT of 600 K. When the temperature dependence of κ was increased to become equal to that of ρ, however, it was found that η/η 0 is increased by about 10% at ΔT = 600 K. It is clarified here that the temperature dependences of ρ and κ are also important factors for an improvement in η

  8. Energy conversion, storage and transportation by means of hydrogen

    International Nuclear Information System (INIS)

    Friedlmeier, G; Mateos, P; Bolcich, J.C.

    1988-01-01

    Data concerning the present consumption of energy indicate that the industrialized countries (representing 25% of the world's population) consume almost 75% of the world's energy production, while the need for energy aimed at maintaining the growth of non-industrialized countries increases day after day. Since estimations indicate that the fossil reverses will exhaust within frightening terms, the production of hydrogen from fossil fuels and, fundamentally, from renewable sources constitute a response to future energy demand. The production of hydrogen from water is performed by four different methods: direct thermal, thermochemical, electrolysis and photolysis. Finally, different ways of storaging and using hydrogen are proposed. (Author)

  9. Electrochemical energy conversion: methanol fuel cell as example

    Directory of Open Access Journals (Sweden)

    Vielstich Wolf

    2003-01-01

    Full Text Available Thermodynamic and kinetic limitations of the electrochemical energy conversion are presented for the case of a methanol/oxygen fuel cell. The detection of intermediates and products is demonstrated using insitu FTIR spectroscopy and online mass spectrometry. The bifunctional catalysis of methanol oxydation by PtRu model surfaces is explained. The formation of HCOOH and HCHO via parallel reaction pathways is discussed. An example of DMFC system technology is presented.

  10. Thorium utilization: conversion ratio and fuel needs in thermal reactors

    International Nuclear Information System (INIS)

    Oosterkamp, W.J.

    1975-01-01

    As a preparatory study for thorium utilization in thermal reactors a study has been made of the fuel comsumption in existing reactor types. A quantitative description is given of the influence of enrichment, burnup, amount of structural material, choise of coolant and control requirements on the convertion ratio. The enrichment is an important factor and a low fuel comsumption can be achieved by increasing the enrichment

  11. 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.

  12. 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

  13. Characterization of date palm frond as a fuel for thermal conversion processes

    Directory of Open Access Journals (Sweden)

    Sadig Hussain

    2017-01-01

    Full Text Available Date palm fronds (DPF have similar physical appearances to those of oil palm fronds and coconut palm fronds, which have been reported as having good potential as a source of energy through thermochemical conversion of biomass. However, nearly no report has been found pertaining to thermochemical properties of DPF. Hence, it has remained unclear whether DPF can become suitable feedstock for power generation. This study investigated the characteristics of DPF as a potential solid fuel for heat and power generation through various thermal conversion processes. DPF samples from selected sites in Sudan and Saudi Arabia were tested. The ultimate and proximate analyses and the calorific value of DPF were measured, and the results were compared with low to medium-rank coals and other common biomass materials. The calorific value range for DPF samples was found to be between 16.2 to 16.9 MJ/kg. The ultimate analysis of DPF samples revealed that more than 75% of their mass was composed of volatile materials, while the ash content in all samples was found to be less than 15%. The range of elementary carbon, hydrogen, nitrogen, sulfur and oxygen in DPF samples was found to be typical to that in biomass. The thermal decomposition trends the samples indicated the high reactivity of DPF with rising temperatures due to high holocellulose content. No distinctive differences in test results were observed between samples from Saudi Arabia and Northern Sudan. Overall, it was found that all DPF samples used in this study fulfilled the typical requirements for development and utilization as a solid fuel.

  14. Characteristic of oil palm residue for energy conversion system

    International Nuclear Information System (INIS)

    Muharnif; Zainal, Z.A.

    2006-01-01

    Malaysia is the major producer of palm oil in the world. It produces 8.5 tones per year (8.5 x 10 6 ty -1 ) of palm oil from 38.6 x 10 6 ty - 1 of fresh fruit bunches. Palm oil production generates large amounts of process residue such as fiber (5.4 x 10 6 ty - 1 ), shell (2.3 x 10 6 ty - 1 ), and empty fruit bunches (8.8 x 10 6 ty - 1 ). A large fraction of the fiber and much of the shell are used as fuel to generate process steam and electricity. The appropriate energy conversion system depends on the characteristic of the oil palm residue. In this paper, a description of characteristic of the oil palm residue is presented. The types of the energy conversion system presented are stoker type combustor and gasified. The paper focuses on the pulverized biomass material and the use of fluidized bed gasified. In the fluidized bed gasified, the palm shell and fiber has to be pulverized before feeding into gasified. For downdraft gasified and furnace, the palm shell and fiber can be used directly into the reactor for energy conversion. The heating value, burning characteristic, ash and moisture content of the oil palm residue are other parameters of the study

  15. Solar Thermal Energy Storage in a Photochromic Macrocycle.

    Science.gov (United States)

    Vlasceanu, Alexandru; Broman, Søren L; Hansen, Anne S; Skov, Anders B; Cacciarini, Martina; Kadziola, Anders; Kjaergaard, Henrik G; Mikkelsen, Kurt V; Nielsen, Mogens Brøndsted

    2016-07-25

    The conversion and efficient storage of solar energy is recognized to hold significant potential with regard to future energy solutions. Molecular solar thermal batteries based on photochromic systems exemplify one possible technology able to harness and apply this potential. Herein is described the synthesis of a macrocycle based on a dimer of the dihydroazulene/vinylheptafulvene (DHA/VHF) photo/thermal couple. By taking advantage of conformational strain, this DHA-DHA macrocycle presents an improved ability to absorb and store incident light energy in chemical bonds (VHF-VHF). A stepwise energy release over two sequential ring-closing reactions (VHF→DHA) combines the advantages of an initially fast discharge, hypothetically addressing immediate energy consumption needs, followed by a slow process for consistent, long-term use. This exemplifies another step forward in the molecular engineering and design of functional organic materials towards solar thermal energy storage and release. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. New bimetallic EMF cell shows promise in direct energy conversion

    Science.gov (United States)

    Hesson, J. C.; Shimotake, H.

    1968-01-01

    Concentration cell, based upon a thermally regenerative cell principle, produces electrical energy from any large heat source. This experimental bimetallic EMF cell uses a sodium-bismuth alloy cathode and a pure liquid sodium anode. The cell exhibits reliability, corrosion resistance, and high current density performance.

  17. Nanostructured materials for advanced energy conversion and storage devices

    Science.gov (United States)

    Aricò, Antonino Salvatore; Bruce, Peter; Scrosati, Bruno; Tarascon, Jean-Marie; van Schalkwijk, Walter

    2005-05-01

    New materials hold the key to fundamental advances in energy conversion and storage, both of which are vital in order to meet the challenge of global warming and the finite nature of fossil fuels. Nanomaterials in particular offer unique properties or combinations of properties as electrodes and electrolytes in a range of energy devices. This review describes some recent developments in the discovery of nanoelectrolytes and nanoelectrodes for lithium batteries, fuel cells and supercapacitors. The advantages and disadvantages of the nanoscale in materials design for such devices are highlighted.

  18. Longitudinal density modulation and energy conversion in intense beams

    International Nuclear Information System (INIS)

    Harris, J. R.; Neumann, J. G.; Tian, K.; O'Shea, P. G.

    2007-01-01

    Density modulation of charged particle beams may occur as a consequence of deliberate action, or may occur inadvertently because of imperfections in the particle source or acceleration method. In the case of intense beams, where space charge and external focusing govern the beam dynamics, density modulation may, under some circumstances, be converted to velocity modulation, with a corresponding conversion of potential energy to kinetic energy. Whether this will occur depends on the properties of the beam and the initial modulation. This paper describes the evolution of discrete and continuous density modulations on intense beams and discusses three recent experiments related to the dynamics of density-modulated electron beams

  19. High-flux/high-temperature solar thermal conversion: technology development and advanced applications

    Directory of Open Access Journals (Sweden)

    Romero Manuel

    2016-01-01

    Full Text Available Solar Thermal Power Plants have generated in the last 10 years a dynamic market for renewable energy industry and a pro-active networking within R&D community worldwide. By end 2015, there are about 5 GW installed in the world, most of them still concentrated in only two countries, Spain and the US, though a rapid process of globalization is taking place in the last few years and now ambitious market deployment is starting in countries like South Africa, Chile, Saudi Arabia, India, United Arab Emirates or Morocco. Prices for electricity produced by today's plants fill the range from 12 to 16 c€/kWh and they are capital intensive with investments above 4000 €/kW, depending on the number of hours of thermal storage. The urgent need to speed up the learning curve, by moving forward to LCOE below 10 c€/kWh and the promotion of sun-to-fuel applications, is driving the R&D programmes. Both, industry and R&D community are accelerating the transformation by approaching high-flux/high-temperature technologies and promoting the integration with high-efficiency conversion systems.

  20. Thermoelectric energy conversion in layered structures with strained Ge quantum dots grown on Si surfaces

    Science.gov (United States)

    Korotchenkov, Oleg; Nadtochiy, Andriy; Kuryliuk, Vasyl; Wang, Chin-Chi; Li, Pei-Wen; Cantarero, Andres

    2014-03-01

    The efficiency of the energy conversion devices depends in many ways on the materials used and various emerging cost-effective nanomaterials have promised huge potentials in highly efficient energy conversion. Here we show that thermoelectric voltage can be enhanced by a factor of 3 using layer-cake growth of Ge quantum dots through thermal oxidation of SiGe layers stacked in SiO2/Si3N4 multilayer structure. The key to achieving this behavior has been to strain the Ge/Si interface by Ge dots migrating to Si substrate. Calculations taking into account the carrier trapping in the dot with a quantum transmission into the neighboring dot show satisfactory agreement with experiments above ≈200 K. The results may be of interest for improving the functionality of thermoelectric devices based on Ge/Si.

  1. 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.

  2. 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.

  3. 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

  4. Food waste-to-energy conversion technologies: current status and future directions.

    Science.gov (United States)

    Pham, Thi Phuong Thuy; Kaushik, Rajni; Parshetti, Ganesh K; Mahmood, Russell; Balasubramanian, Rajasekhar

    2015-04-01

    Food waste represents a significantly fraction of municipal solid waste. Proper management and recycling of huge volumes of food waste are required to reduce its environmental burdens and to minimize risks to human health. Food waste is indeed an untapped resource with great potential for energy production. Utilization of food waste for energy conversion currently represents a challenge due to various reasons. These include its inherent heterogeneously variable compositions, high moisture contents and low calorific value, which constitute an impediment for the development of robust, large scale, and efficient industrial processes. Although a considerable amount of research has been carried out on the conversion of food waste to renewable energy, there is a lack of comprehensive and systematic reviews of the published literature. The present review synthesizes the current knowledge available in the use of technologies for food-waste-to-energy conversion involving biological (e.g. anaerobic digestion and fermentation), thermal and thermochemical technologies (e.g. incineration, pyrolysis, gasification and hydrothermal oxidation). The competitive advantages of these technologies as well as the challenges associated with them are discussed. In addition, the future directions for more effective utilization of food waste for renewable energy generation are suggested from an interdisciplinary perspective. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Solar energy conversion by photocatalytic overall water splitting

    KAUST Repository

    Takanabe, Kazuhiro

    2015-07-04

    Summary: Solar energy is abundant and renewable energy: however, extensive conversion of the solar energy can only be achieved by large-scale collection of solar flux. The technology that satisfies this requirement must be as simple as possible to reduce capital cost. Overall water splitting (OWS) by powder-form photocatalysts directly produces H2 as a chemical energy in a single reactor, which does not require any complicated parabolic mirrors and electronic devices. Because of its simplicity and low capital cost, it has tremendous potential to become the major technology of solar energy conversion. To achieve the OWS efficiently, the development of efficient photocatalysts is mandatory. The OWS hotocatalysis involves the electrocatalys is for both water reduction and oxidation on the surafce of photocatalysts, which is driven by particular semiconductors that absorb photons to generate excited carriers. Such photocatalysts must be designed to maximize the charge separation efficiency at the catalyst-semiconductor and semiconductor-electrolyte interface. In addition the low-overpotential electrocatalyts towards water redox reactions should be insensitive to the back-reaction of the produced H2 and O2 that produces H2O. In this presentation, some recent progress on the topic of the OWS in our group will be discussed.

  6. Romania needs a strategy for thermal energy

    Directory of Open Access Journals (Sweden)

    Leca Aureliu

    2015-06-01

    Full Text Available The energy sector in Romania consists of three sub-sectors: electricity, natural gas and heat. Among these, the sub-sector of thermal energy is in the most precarious situation because it has been neglected for a long time. This sub-sector is particularly important both due to the amount of final heat consumption (of over 50% of final energy consumption, and to the fact that it has a direct negative effect on the population, industry and services. This paper presents the main directions for developing a modern strategy of the thermal energy sub-sector, which would fit into Romania’s Energy Strategy that is still in preparation This is based on the author’s 50 years of experience in this field that includes knowledge about the processes and the equipment of thermal energy, expertise in the management and restructuring of energy companies and also knowledge of the specific legislation. It is therefore recommended, following the European regulations and practices, the promotion and upgrading of district heating systems using efficient cogeneration, using trigeneration in Romania, modernizing buildings in terms of energy use, using of renewable energy sources for heating, especially biomass, and modernizing the energy consumption of rural settlements.

  7. An estimate of spherical impactor energy transfer for mechanical frequency up-conversion energy harvester

    Directory of Open Access Journals (Sweden)

    L. R. Corr

    2016-08-01

    Full Text Available Vibration energy harvesters, which use the impact mechanical frequency up-conversion technique, utilize an impactor, which gains kinetic energy from low frequency ambient environmental vibrations, to excite high frequency systems that efficiently convert mechanical energy to electrical energy. To take full advantage of the impact mechanical frequency up-conversion technique, it is prudent to understand the energy transfer from the low frequency excitations, to the impactor, and finally to the high frequency systems. In this work, the energy transfer from a spherical impactor to a multi degree of freedom spring / mass system, due to Hertzian impact, is investigated to gain insight on how best to design impact mechanical frequency up-conversion energy harvesters. Through this academic work, it is shown that the properties of the contact (or impact area, i.e., radius of curvature and material properties, only play a minor role in energy transfer and that the equivalent mass of the target system (i.e., the spring / mass system dictates the total amount of energy transferred during the impact. The novel approach of utilizing the well-known Hertzian impact methodology to gain an understanding of impact mechanical frequency up-conversion energy harvesters has made it clear that the impactor and the high frequency energy generating systems must be designed together as one system to ensure maximum energy transfer, leading to efficient ambient vibration energy harvesters.

  8. 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.

  9. Advanced fluoride-based materials for energy conversion

    CERN Document Server

    Nakajima, Tsuyoshi

    2015-01-01

    Advanced Fluoride-Based Materials for Energy Conversion provides thorough and applied information on new fluorinated materials for chemical energy devices, exploring the electrochemical properties and behavior of fluorinated materials in lithium ion and sodium ion batteries, fluoropolymers in fuel cells, and fluorinated carbon in capacitors, while also exploring synthesis applications, and both safety and stability issues. As electronic devices, from cell phones to hybrid and electric vehicles, are increasingly common and prevalent in modern lives and require dependable, stable chemical energy devices with high-level functions are becoming increasingly important. As research and development in this area progresses rapidly, fluorine compounds play a critical role in this rapid progression. Fluorine, with its small size and the highest electronegativity, yields stable compounds under various conditions for utilization as electrodes, electrolytes, and membranes in energy devices. The book is an ideal reference f...

  10. Conversion of broadband thermal radiation in lithium niobate crystals of various compositions

    Science.gov (United States)

    Syuy, A. V.; Litvinova, M. N.; Goncharova, P. S.; Sidorov, N. V.; Palatnikov, M. N.; Krishtop, V. V.; Likhtin, V. V.

    2013-05-01

    The conversion of the broadband thermal radiation in stoichiometric ( R = 1) lithium niobate single crystals that are grown from melt with 58.6 mol % of LiO2, congruent ( R = Li/Nb = 0.946) melt with the K2O flux admixture (4.5 and 6.0 wt %), and congruent melt and in congruent single crystals doped with the Zn2+, Gd3+, and Er3+ cations is studied. It is demonstrated that the conversion efficiency of the stoichiometric crystal that is grown from the melt with 58.6 mol % of LiO2 is less than the conversion efficiency of congruent crystal. In addition, the stoichiometric and almost stoichiometric crystals and the doped congruent crystals exhibit the blue shift of the peak conversion intensity in comparison with a nominally pure congruent crystal. For the congruent crystals, the conversion intensities peak at 520 and 495 nm, respectively.

  11. Optical and thermal energy discharge from tritiated solid hydrogen

    International Nuclear Information System (INIS)

    Magnotta, F.; Mapoles, E.R.; Collins, G.W.; Souers, P.C.

    1991-01-01

    The authors are investigating mechanisms of energy storage and release in tritiated solid hydrogens, by a variety of techniques including ESR, NMR and thermal and optical emission. The nuclear decay of a triton in solid hydrogen initiates the conversion of nuclear energy into stored chemical energy by producing unpaired hydrogen atoms which are trapped within the molecular lattice. The ability to store large quantities of atoms in this manner has been demonstrated and can serve as a basis for new forms of high energy density materials. This paper presents preliminary results of a study of the optical emission from solid hydrogen containing tritium over the visible and near infrared (NIR) spectral regions. Specifically, they have studied optical emission from DT and T 2 using CCD, silicon diode and germanium diode arrays. 8 refs., 6 figs

  12. The Generalized Conversion Factor in Einstein's Mass-Energy Equation

    Directory of Open Access Journals (Sweden)

    Ajay Sharma

    2008-07-01

    Full Text Available Einstein's September 1905 paper is origin of light energy-mass inter conversion equation ($L = Delta mc^{2}$ and Einstein speculated $E = Delta mc^{2}$ from it by simply replacing $L$ by $E$. From its critical analysis it follows that $L = Delta mc^{2}$ is only true under special or ideal conditions. Under general cases the result is $L propto Delta mc^{2}$ ($E propto Delta mc^{2}$. Consequently an alternate equation $Delta E = A ub c^{2}Delta M$ has been suggested, which implies that energy emitted on annihilation of mass can be equal, less and more than predicted by $Delta E = Delta mc^{2}$. The total kinetic energy of fission fragments of U-235 or Pu-239 is found experimentally 20-60 MeV less than Q-value predicted by $Delta mc^{2}$. The mass of particle Ds (2317 discovered at SLAC, is more than current estimates. In many reactions including chemical reactions $E = Delta mc^{2}$ is not confirmed yet, but regarded as true. It implies the conversion factor than $c^{2}$ is possible. These phenomena can be explained with help of generalized mass-energy equation $Delta E = A ub c^{2}Delta M$.

  13. Synthesis and characterization of zirconia electrolytes for potential use in energy conversion

    International Nuclear Information System (INIS)

    Wheat, T.A.

    1978-11-01

    The present work is part of a program to develop ionically conducting materials for potential use in energy storage and conversion systems. With applications in high energy-density batteries, magneto-hydrodynamic (MHD) generators, fuel cells and sensors, they ae playing an increasinly important role in developing more efficient energy storage and conversion devices. Using a wet-chemical procedure, a series of compostions having between 0 and 22.2 mol percent CaO in zirconia, was prepared and subsequently formed into sintered samples having a relative density from 95 to 98 percent. Sintered samples were prepared of each composition with a geometry appropriate for determining the thermal, electrical or microstructural characteristics. This report covers only the microstructural aspects of powder synthesis and the development of sintered materials. Using the reactive, homogeneous, chemically prepared powders, it has been shown that cubic and monoclinic zirconia can coexist in compositions containing up to 10 mol percent CaO. From 10 to 20 mol percent CaO, only the cubic phase is formed, whereas at higher CaO concentrations the cubic phase coexits with CaZro 3 . The change from a two-phase to single-phase system as the CaO concentration is increased above 10 mol percent, increases the grain size nearly an order of magnitude. It has been found that 5 and 7.6 mol percent CaO materials develop considerable stress during the cooling stage of the firing cycle. As a result, they undergo a progressive and irreversible expansion with each thermal shock cycle: the magnitude of the expansion is proportional to the severity of the thermal shock. The microstructural texture of these partially stablilized materials was also shown to be dependent on the thermal history and hence a strong dependence of the electrical and thermal properties can be anticipated. (auth)

  14. Behaviour of heavy metals during the thermal conversion of sawdust in an entrained flow reactor

    Energy Technology Data Exchange (ETDEWEB)

    Klensch, S.; Reimert, R. [Engler-Bunte-Inst., Bereich Gas, Erdoel und Kohle, Univ. Karlsruhe, Karlsruhe (Germany)

    1999-07-01

    Since its utilization is nearly CO{sub 2}-neutral, biomass represents a major alternative energy carrier in comparison with fossil fuels in CO{sub 2} reduction scenarios frequently discussed. Decentral generation of power and heat in medium sized plants could develop as a preferred application in future. During thermal conversion (gasification and combustion) of biomass the inorganic matter including the heavy metals will be found in the solid residues, i. e. slags and ashes, and in very low concentrations in the product gas (fuel or flue gas). The ashes should be returned to the forests and the agricultural areas respectively to avoid the use of industrial fertilizers. However, for this purpose the heavy metal concentrations of ashes may not exceed specific limit values, otherwise the returned ashes can lead to harmful effects on the ecological system. In awareness of this problem, in Austria some limit values for the concentrations of Cd, Cr, Cu, Ni, Pb and Zn in returned ashes are valid since 1997. No danger for the environment can be expected by slags containing heavy metals. The heavy metals are fixed environmentally neutral in the glass matrix as has been proven for coal and for residue gasification many times. Dividing the total of the residues into such two streams (returned ash and slag) avoids the disposal of the ashes. The heavy metal behaviour during the thermal conversion of sawdust was investigated in a bench scale plant. In essence, the plant consists of an entrained flow reactor (length of reaction zone: 2,500 mm; inner diameter: 70 mm) and a candle barrier filter with 6 rigid ceramic filter elements (DIA-Schumalith 10-20). The biomass flow rate is as high as 6 kg/h and the operating pressure is about 0.12 MPa. Experimental results show the influences of the conversion temperature (1100 - 1300 C), of the dedusting temperature (350 - 800 C), and of the gas atmosphere (reducing, oxidising) on the heavy metal concentrations of the slag and of the fly

  15. Solar Thermal Energy; Energia Solar Termica

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Martinez, M; Cuesta-Santianes, M J; Cabrera Jimenez, J A

    2008-07-01

    Approximately, 50 % of worldwide primary energy consumption is done in the form of heat in applications with a temperature lower than 250 degree centigree (low-medium temperature heat). These data clearly demonstrate the great potential of solar thermal energy to substitute conventional fossil fuels, which are becoming more expensive and are responsible for global warming. Low-medium temperature solar thermal energy is mainly used to obtain domestic hot water and provide space heating. Active solar thermal systems are those related to the use of solar thermal collectors. This study is dealing with low temperature solar thermal applications, mainly focusing on active solar thermal systems. This kind of systems has been extensively growing worldwide during the last years. At the end of 2006, the collector capacity in operation worldwide equalled 127.8 GWth. The technology is considered to be already developed and actions should be aimed at favouring a greater market penetration: diffusion, financial support, regulations establishment, etc. China and USA are the leading countries with a technology based on evacuated tube collectors and unglazed collectors, respectively. The rest of the world markets are dominated by the flat glazed collectors technology. (Author) 15 refs.

  16. Electrochemical energy storage systems for solar thermal applications

    Science.gov (United States)

    Krauthamer, S.; Frank, H.

    1980-01-01

    Existing and advanced electrochemical storage and inversion/conversion systems that may be used with terrestrial solar-thermal power systems are evaluated. The status, cost and performance of existing storage systems are assessed, and the cost, performance, and availability of advanced systems are projected. A prime consideration is the cost of delivered energy from plants utilizing electrochemical storage. Results indicate that the five most attractive electrochemical storage systems are the: iron-chromium redox (NASA LeRC), zinc-bromine (Exxon), sodium-sulfur (Ford), sodium-sulfur (Dow), and zinc-chlorine (EDA).

  17. Thermal energy storage in granular deposits

    Science.gov (United States)

    Ratuszny, Paweł

    2017-10-01

    Energy storage technology is crucial for the development of the use of renewable energy sources. This is a substantial constraint, however it can, to some extent, be solved by storing energy in its various forms: electrical, mechanical, chemical and thermal. This article presents the results of research in thermal properties of granular deposits. Correlation between temperature changes in the stores over a period of time and their physical properties has been studied. The results of the research have practical application in designing thermal stores based on bulk materials and ground deposits. Furthermore, the research results are significant for regeneration of the lower ground sources for heat pumps and provide data for designing ground heat exchangers for ventilation systems.

  18. Aquifer thermal energy storage in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Iihola, H; Ala-Peijari, T; Seppaenen, H

    1988-01-01

    The rapid changes and crises in the field of energy during the 1970s and 1980s have forced us to examine the use of energy more critically and to look for new ideas. Seasonal aquifer thermal energy storage (T < 100/sup 0/C) on a large scale is one of the grey areas which have not yet been extensively explored. However, projects are currently underway in a dozen countries. In Finland there have been three demonstration projects from 1974 to 1987. International co-operation under the auspices of the International Energy Agency, Annex VI, 'Environmental and Chemical Aspects of Thermal Energy Storage in Aquifers and Research and Development of Water Treatment Methods' started in 1987. The research being undertaken in 8 countries includes several elements fundamental to hydrochemistry and biochemistry.

  19. Energy conservation through thermally insulated structures

    International Nuclear Information System (INIS)

    Abu-Dayyeh, Ayoub

    2006-01-01

    The propose of this paper is to explicate its title through investigating the different available thermal insulating materials and the various techniques of application, as practiced in Jordan, in particular, and as practiced in many parts of the world in general, which will satisfy Jordanian standards in terms of heat transmittance and thermal comfort. A brief comparison with international standards will shed some light on the stringent measures enforced in the developed world and on our striving aspirations to keep pace. The paper consists of four main parts, pseudoally divided. The first part will deal with the mechanism of heat loss and heat gain in structures during summer and winter. It will also explain the Time-lag phenomenon which is vital for providing thermal comfort inside the dwellings. The second part will evaluate the damages induced by the temperature gradients on the different elements of the structure, particularly next to exterior opening. The paper will also demonstrate the damages induced by water condensation and fungus growth on the internal surfaces of the structure and within its skeleton. A correlation between condensation and thermal insulation will be established. The third part of the paper will evaluate the different available thermal insulating materials and the application techniques which will satisfy the needs for thermal insulating and thermal comfort at the least cost possible. The criteria of an economical design shall be established. As a conclusion, the paper infers answers to the following different criteria discussed throughout the different parts of the paper. The main theme of questions can be summarized as follows: 1)How energy conservation is possible due to thermal insulation? 2)The feasibility of investing in thermal insulation? 3)Is thermal comfort and a healthy atmosphere possible inside the dwellings during all season! What are the conditions necessary to sustain them? 4)What environmental impacts can exist due to

  20. Renewable energy from corn residues by thermochemical conversion

    Science.gov (United States)

    Yu, Fei

    Declining fossil oil reserve, skyrocket price, unsecured supplies, and environment pollution are among the many energy problems we are facing today. It is our conviction that renewable energy is a solution to these problems. The long term goal of the proposed research is to develop commercially practical technologies to produce energy from renewable resources. The overall objective of my research is to study and develop thermochemical processes for converting bulky and low-energy-density biomass materials into bio-fuels and value-added bio-products. The rationale for the proposed research is that, once such processes are developed, processing facility can be set up on or near biomass product sites, reducing the costs associated with transport of bulky biomass which is a key technical barrier to biomass conversion. In my preliminary research, several conversion technologies including atmospheric pressure liquefaction, high pressure liquefaction, and microwave pyrolysis have been evaluated. Our data indicated that microwave pyrolysis had the potential to become a simple and economically viable biomass conversion technology. Microwave pyrolysis is an innovative process that provides efficient and uniform heating, and are robust to type, size and uniformity of feedstock and therefore suitable for almost any waste materials without needing to reduce the particle size. The proposed thesis focused on in-depth investigations of microwave pyrolysis of corn residues. My first specific aim was to examine the effects of processing parameters on product yields. The second specific research aim was to characterize the products (gases, bio-oils, and solid residues), which was critical to process optimization and product developments. Other research tasks included conducting kinetic modeling and preliminary mass and energy balance. This study demonstrated that microwave pyrolysis could be optimized to produce high value syngas, liquid fuels and pyrolytic carbons, and had a great

  1. Solar applications of thermal energy storage. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.; Taylor, L.; DeVries, J.; Heibein, S.

    1979-01-01

    A technology assessment is presented on solar energy systems which use thermal energy storage. The study includes characterization of the current state-of-the-art of thermal energy storage, an assessment of the energy storage needs of solar energy systems, and the synthesis of this information into preliminary design criteria which would form the basis for detailed designs of thermal energy storage. (MHR)

  2. Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masaaki; Yoo, Jongsoo; Jara-Almonte, Jonathan; Ji, Hantao; Kulsrud, Russell M.; Myers, Clayton E. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Daughton, William [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2015-05-15

    While the most important feature of magnetic reconnection is that it energizes plasma particles by converting magnetic energy to particle energy, the exact mechanisms by which this happens are yet to be determined despite a long history of reconnection research. Recently, we have reported our results on the energy conversion and partitioning in a laboratory reconnection layer in a short communication [Yamada et al., Nat. Commun. 5, 4474 (2014)]. The present paper is a detailed elaboration of this report together with an additional dataset with different boundary sizes. Our experimental study of the reconnection layer is carried out in the two-fluid physics regime where ions and electrons move quite differently. We have observed that the conversion of magnetic energy occurs across a region significantly larger than the narrow electron diffusion region. A saddle shaped electrostatic potential profile exists in the reconnection plane, and ions are accelerated by the resulting electric field at the separatrices. These accelerated ions are then thermalized by re-magnetization in the downstream region. A quantitative inventory of the converted energy is presented in a reconnection layer with a well-defined, variable boundary. We have also carried out a systematic study of the effects of boundary conditions on the energy inventory. This study concludes that about 50% of the inflowing magnetic energy is converted to particle energy, 2/3 of which is ultimately transferred to ions and 1/3 to electrons. Assisted by another set of magnetic reconnection experiment data and numerical simulations with different sizes of monitoring box, it is also observed that the observed features of energy conversion and partitioning do not depend on the size of monitoring boundary across the range of sizes tested from 1.5 to 4 ion skin depths.

  3. LiH thermal energy storage device

    Science.gov (United States)

    Olszewski, M.; Morris, D.G.

    1994-06-28

    A thermal energy storage device for use in a pulsed power supply to store waste heat produced in a high-power burst operation utilizes lithium hydride as the phase change thermal energy storage material. The device includes an outer container encapsulating the lithium hydride and an inner container supporting a hydrogen sorbing sponge material such as activated carbon. The inner container is in communication with the interior of the outer container to receive hydrogen dissociated from the lithium hydride at elevated temperatures. 5 figures.

  4. Innovative rubble mound breakwaters for wave energy conversion

    International Nuclear Information System (INIS)

    Contestabile, Pasquale; Vicinanza, Diego; Iuppa, Claudio; Cavallaro, Luca; Foti, Enrico

    2015-01-01

    This paper presents a new Wave Energy Converter named Overtopping BReakwater for Energy Conversion (OBREC) which consists of a rubble mound breakwater with a front reservoir designed with the aim of capturing the wave overtopping in order to produce electricity. The energy is extracted via low head turbines, using the difference in water levels between the reservoir and the mean sea water level. The new design should be capable of adding a revenue generation function to a breakwater while adding cost sharing benefits due to integration. The design can be applied to harbour expansions, existing breakwater maintenance or upgrades due to climate change for a relatively low cost, considering the breakwater would be built regardless of the inclusion of a WEC [it

  5. Experimental investigation of rubble mound breakwaters for wave energy conversion

    DEFF Research Database (Denmark)

    Luppa, C.; Contestabile, P.; Cavallaro, L.

    2015-01-01

    The paper describes recent laboratory investigation on the breakwater integrated device named “OBREC” (Overtopping BReakwater for Energy Conversion). This technology recently appeared on the wave energy converter scene as an executive outcome of improving composite seawalls by including overtoppi......-by-wave measurement of couples of hydraulic head-flow rate acting on a virtual turbine inlet. Finally, the influence of draft length on overtopping discharge has been identified....... type wave energy converters [1]. Two complementary experimental campaigns were carried out, in 2012 and in 2014. Several geometries and wave conditions were examined. Preliminary comparison of hydraulic behaviour has been summarized, focusing on reflection analysis and overtopping flow rate....... Preliminary design formulae are presented to predict overtopping at the rear side of the structure and in to the front reservoir based on both datasets. Moreover, some important results have been presented on hydraulic behaviour of OBREC with saturated reservoir. Particularly attention is paid to wave...

  6. Progress and Perspectives of Plasmon-Enhanced Solar Energy Conversion.

    Science.gov (United States)

    Cushing, Scott K; Wu, Nianqiang

    2016-02-18

    Plasmonics allows extraordinary control of light, making it attractive for application in solar energy harvesting. In metal-semiconductor heterojunctions, plasmons can enhance photoconversion in the semiconductor via three mechanisms, including light trapping, hot electron/hole transfer, and plasmon-induced resonance energy transfer (PIRET). To understand the plasmonic enhancement, the metal's geometry, constituent metal, and interface must be viewed in terms of the effects on the plasmon's dephasing and decay route. To simplify design of plasmonic metal-semiconductor heterojunctions for high-efficiency solar energy conversion, the parameters controlling the plasmonic enhancement can be distilled to the dephasing time. The plasmonic geometry can then be further refined to optimize hot carrier transfer, PIRET, or light trapping.

  7. Artificial photosynthesis: biomimetic approaches to solar energy conversion and storage.

    Science.gov (United States)

    Kalyanasundaram, K; Graetzel, M

    2010-06-01

    Using sun as the energy source, natural photosynthesis carries out a number of useful reactions such as oxidation of water to molecular oxygen and fixation of CO(2) in the form of sugars. These are achieved through a series of light-induced multi-electron-transfer reactions involving chlorophylls in a special arrangement and several other species including specific enzymes. Artificial photosynthesis attempts to reconstruct these key processes in simpler model systems such that solar energy and abundant natural resources can be used to generate high energy fuels and restrict the amount of CO(2) in the atmosphere. Details of few model catalytic systems that lead to clean oxidation of water to H(2) and O(2), photoelectrochemical solar cells for the direct conversion of sunlight to electricity, solar cells for total decomposition of water and catalytic systems for fixation of CO(2) to fuels such as methanol and methane are reviewed here. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. WO3 and W Thermal Atomic Layer Etching Using "Conversion-Fluorination" and "Oxidation-Conversion-Fluorination" Mechanisms.

    Science.gov (United States)

    Johnson, Nicholas R; George, Steven M

    2017-10-04

    The thermal atomic layer etching (ALE) of WO 3 and W was demonstrated with new "conversion-fluorination" and "oxidation-conversion-fluorination" etching mechanisms. Both of these mechanisms are based on sequential, self-limiting reactions. WO 3 ALE was achieved by a "conversion-fluorination" mechanism using an AB exposure sequence with boron trichloride (BCl 3 ) and hydrogen fluoride (HF). BCl 3 converts the WO 3 surface to a B 2 O 3 layer while forming volatile WO x Cl y products. Subsequently, HF spontaneously etches the B 2 O 3 layer producing volatile BF 3 and H 2 O products. In situ spectroscopic ellipsometry (SE) studies determined that the BCl 3 and HF reactions were self-limiting versus exposure. The WO 3 ALE etch rates increased with temperature from 0.55 Å/cycle at 128 °C to 4.19 Å/cycle at 207 °C. W served as an etch stop because BCl 3 and HF could not etch the underlying W film. W ALE was performed using a three-step "oxidation-conversion-fluorination" mechanism. In this ABC exposure sequence, the W surface is first oxidized to a WO 3 layer using O 2 /O 3 . Subsequently, the WO 3 layer is etched with BCl 3 and HF. SE could simultaneously monitor the W and WO 3 thicknesses and conversion of W to WO 3 . SE measurements showed that the W film thickness decreased linearly with number of ABC reaction cycles. W ALE was shown to be self-limiting with respect to each reaction in the ABC process. The etch rate for W ALE was ∼2.5 Å/cycle at 207 °C. An oxide thickness of ∼20 Å remained after W ALE, but could be removed by sequential BCl 3 and HF exposures without affecting the W layer. These new etching mechanisms will enable the thermal ALE of a variety of additional metal materials including those that have volatile metal fluorides.

  9. Modeling energy flexibility of low energy buildings utilizing thermal mass

    DEFF Research Database (Denmark)

    Foteinaki, Kyriaki; Heller, Alfred; Rode, Carsten

    2016-01-01

    In the future energy system a considerable increase in the penetration of renewable energy is expected, challenging the stability of the system, as both production and consumption will have fluctuating patterns. Hence, the concept of energy flexibility will be necessary in order for the consumption...... to match the production patterns, shifting demand from on-peak hours to off-peak hours. Buildings could act as flexibility suppliers to the energy system, through load shifting potential, provided that the large thermal mass of the building stock could be utilized for energy storage. In the present study...... the load shifting potential of an apartment of a low energy building in Copenhagen is assessed, utilizing the heat storage capacity of the thermal mass when the heating system is switched off for relieving the energy system. It is shown that when using a 4-hour preheating period before switching off...

  10. 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)

  11. 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)

  12. Visible light to electrical energy conversion using photoelectrochemical cells

    Science.gov (United States)

    Wrighton, Mark S. (Inventor); Ellis, Arthur B. (Inventor); Kaiser, Steven W. (Inventor)

    1983-01-01

    Sustained conversion of low energy visible or near i.r. light (>1.25 eV) to electrical energy has been obtained using wet photoelectrochemical cells where there are no net chemical changes in the system. Stabilization of n-type semi-conductor anodes of CdS, CdSe, CdTe, GaP, GaAs and InP to photoanodic dissolution is achieved by employing selected alkaline solutions of Na.sub.2 S, Na.sub.2 S/S, Na.sub.2 Se, Na.sub.2 Se/Se, Na.sub.2 Te and Na.sub.2 Te/Te as the electrolyte. The oxidation of (poly) sulfide, (poly)selenide or (poly)telluride species occurs at the irradiated anode, and reduction of polysulfide, polyselenide or polytelluride species occurs at the dark Pt cathode of the photoelectrochemical cell. Optical to electrical energy conversion efficiencies approaching 15% at selected frequencies have been observed in some cells. The wavelength for the onset of photocurrent corresponds to the band gap of the particular anode material used in the cell.

  13. 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.

  14. 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.

  15. Energy conversion of source separated packaging; Energiutvinning ur kaellsorterade foerpackningsfraktioner

    Energy Technology Data Exchange (ETDEWEB)

    Blidholm, O; Wiklund, S E [AaF-Energikonsult (Sweden); Bauer, A C [Energikonsult A. Bauer (Sweden)

    1997-02-01

    The basic idea of this project is to study the possibilities to use source separated combustible material for energy conversion in conventional solid fuel boilers (i.e. not municipal waste incineration plants). The project has been carried out in three phases. During phase 1 and 2 a number of fuel analyses of different fractions were carried out. During phase 3 two combustion tests were carried out; (1) a boiler with grate equipped with cyclone, electrostatic precipitator and flue gas condenser, and (2) a bubbling fluidized bed boiler with electrostatic precipitator and flue gas condenser. During the tests source separated paper and plastic packagings were co-fired with biomass fuels. The mixing rate of packagings was approximately 15%. This study reports the results of phase 3 and the conclusions of the whole project. The technical terms of using packaging as fuel are good. The technique is available for shredding both paper and plastic packaging. The material can be co-fired with biomass. The economical terms of using source separated packaging for energy conversion can be very advantageous, but can also form obstacles. The result is to a high degree guided by such facts as how the fuel is collected, transported, reduced in size and handled at the combustion plant. The results of the combustion tests show that the environmental terms of using source separated packaging for energy conversion are good. The emissions of heavy metals into the atmosphere are very low. The emissions are well below the emission standards for waste incineration plants. 35 figs, 13 tabs, 8 appendices

  16. Aquifer thermal energy storage. International symposium: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    Aquifers have been used to store large quantities of thermal energy to supply process cooling, space cooling, space heating, and ventilation air preheating, and can be used with or without heat pumps. Aquifers are used as energy sinks and sources when supply and demand for energy do not coincide. Aquifer thermal energy storage may be used on a short-term or long-term basis; as the sole source of energy or as a partial storage; at a temperature useful for direct application or needing upgrade. The sources of energy used for aquifer storage are ambient air, usually cold winter air; waste or by-product energy; and renewable energy such as solar. The present technical, financial and environmental status of ATES is promising. Numerous projects are operating and under development in several countries. These projects are listed and results from Canada and elsewhere are used to illustrate the present status of ATES. Technical obstacles have been addressed and have largely been overcome. Cold storage in aquifers can be seen as a standard design option in the near future as it presently is in some countries. The cost-effectiveness of aquifer thermal energy storage is based on the capital cost avoidance of conventional chilling equipment and energy savings. ATES is one of many developments in energy efficient building technology and its success depends on relating it to important building market and environmental trends. This paper attempts to provide guidance for the future implementation of ATES. Individual projects have been processed separately for entry onto the Department of Energy databases.

  17. Advanced solar energy conversion. [solar pumped gas lasers

    Science.gov (United States)

    Lee, J. H.

    1981-01-01

    An atomic iodine laser, a candidate for the direct solar pumped lasers, was successfully excited with a 4 kW beam from a xenon arc solar simulator, thus proving the feasibility of the concept. The experimental set up and the laser output as functions of operating conditions are presented. The preliminary results of the iodine laser amplifier pumped with the HCP array to which a Q switch for giant pulse production was coupled are included. Two invention disclosures - a laser driven magnetohydrodynamic generator for conversion of laser energy to electricity and solar pumped gas lasers - are also included.

  18. Novel silicon phases and nanostructures for solar energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Wippermann, Stefan; He, Yuping; Vörös, Márton; Galli, Giulia

    2016-12-01

    Silicon exhibits a large variety of different bulk phases, allotropes, and composite structures, such as, e.g., clathrates or nanostructures, at both higher and lower densities compared with diamond-like Si-I. New Si structures continue to be discovered. These novel forms of Si offer exciting prospects to create Si based materials, which are non-toxic and earth-abundant, with properties tailored precisely towards specific applications. We illustrate how such novel Si based materials either in the bulk or as nanostructures may be used to significantly improve the efficiency of solar energy conversion devices.

  19. 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)

  20. Characterization of second generation biomass under thermal conversion and the fate of nitrogen

    NARCIS (Netherlands)

    Giuntoli, J.

    2010-01-01

    This dissertation deals with the characterization of several biomass materials under thermal conversion conditions using small--scale equipment. The fuels are tested under the conditions of slow and fast heating rate pyrolysis and combustion, with the main goal of investigating the chemistry of

  1. Advanced nanostructured materials for energy storage and conversion

    Science.gov (United States)

    Hutchings, Gregory S.

    Due to a global effort to reduce greenhouse gas emissions and to utilize renewable sources of energy, much effort has been directed towards creating new alternatives to fossil fuels. Identifying novel materials for energy storage and conversion can enable radical changes to the current fuel production infrastructure and energy utilization. The use of engineered nanostructured materials in these systems unlocks unique catalytic activity in practical configurations. In this work, research efforts have been focused on the development of nanostructured materials to address the need for both better energy conversion and storage, with applications toward Li-O2 battery electrocatalysts, electrocatalytic generation of H2, conversion of furfural to useful chemicals and fuels, and Li battery anode materials. Highly-active alpha-MnO2 materials were synthesized for use as bifunctional oxygen reduction (ORR) and evolution (OER) catalysts in Li-O2 batteries, and were evaluated under operating conditions with a novel in situ X-ray absorption spectroscopy configuration. Through detailed analysis of local coordination and oxidation states of Mn atoms at key points in the electrochemical cycle, a self-switching behavior affecting the bifunctional activity was identified and found to be critical. In an additional study of materials for lithium batteries, nanostructured TiO2 anode materials doped with first-row transition metals were synthesized and evaluated for improving battery discharge capacity and rate performance, with Ni and Co doping at low levels found to cause the greatest enhancement. In addition to battery technology research, I have also sought to find inexpensive and earth-abundant electrocatalysts to replace state-of-the-art Pt/C in the hydrogen evolution reaction (HER), a systematic computational study of Cu-based bimetallic electrocatalysts was performed. During the screening of dilute surface alloys of Cu mixed with other first-row transition metals, materials with

  2. Dynamic tuning of optical absorbers for accelerated solar-thermal energy storage.

    Science.gov (United States)

    Wang, Zhongyong; Tong, Zhen; Ye, Qinxian; Hu, Hang; Nie, Xiao; Yan, Chen; Shang, Wen; Song, Chengyi; Wu, Jianbo; Wang, Jun; Bao, Hua; Tao, Peng; Deng, Tao

    2017-11-14

    Currently, solar-thermal energy storage within phase-change materials relies on adding high thermal-conductivity fillers to improve the thermal-diffusion-based charging rate, which often leads to limited enhancement of charging speed and sacrificed energy storage capacity. Here we report the exploration of a magnetically enhanced photon-transport-based charging approach, which enables the dynamic tuning of the distribution of optical absorbers dispersed within phase-change materials, to simultaneously achieve fast charging rates, large phase-change enthalpy, and high solar-thermal energy conversion efficiency. Compared with conventional thermal charging, the optical charging strategy improves the charging rate by more than 270% and triples the amount of overall stored thermal energy. This superior performance results from the distinct step-by-step photon-transport charging mechanism and the increased latent heat storage through magnetic manipulation of the dynamic distribution of optical absorbers.

  3. Thermal solar energy, towards a sunny interval?

    International Nuclear Information System (INIS)

    Anon.

    2017-01-01

    While its market results are continuously decreasing, the thermal solar sector regains confidence with the perspectives of a new thermal legislation in France, a higher carbon tax and the growing volume of installed equipment. This document contains 5 articles, which themes are: The renewal of the thermal solar energy sector in France, notably for the building market, due to a new regulation and a reduction in costs; Several companies are developing large capacity thermal solar plant for industrial facilities (one of them covers 10000 m 2 ) while another company is developing an all-in-one containerised system (less than 1 MW); Another example is given with a Caribbean chemical company which use thermal solar energy for its processes, with a reduction of the fuel consumption by a 2.5 factor; The return of experience show that hybrid solar panels present some limitations, especially in terms of performances and sizing; A collective building (35 apartments) in the West of France has 100 pc of its heating needs (hot water production and space heating) satisfied with solar energy

  4. Enhancing radiative energy transfer through thermal extraction

    Directory of Open Access Journals (Sweden)

    Tan Yixuan

    2016-06-01

    Full Text Available Thermal radiation plays an increasingly important role in many emerging energy technologies, such as thermophotovoltaics, passive radiative cooling and wearable cooling clothes [1]. One of the fundamental constraints in thermal radiation is the Stefan-Boltzmann law, which limits the maximum power of far-field radiation to P0 = σT4S, where σ is the Boltzmann constant, S and T are the area and the temperature of the emitter, respectively (Fig. 1a. In order to overcome this limit, it has been shown that near-field radiations could have an energy density that is orders of magnitude greater than the Stefan-Boltzmann law [2-7]. Unfortunately, such near-field radiation transfer is spatially confined and cannot carry radiative heat to the far field. Recently, a new concept of thermal extraction was proposed [8] to enhance far-field thermal emission, which, conceptually, operates on a principle similar to oil immersion lenses and light extraction in light-emitting diodes using solid immersion lens to increase light output [62].Thermal extraction allows a blackbody to radiate more energy to the far field than the apparent limit of the Stefan-Boltzmann law without breaking the second law of thermodynamics.

  5. 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)

  6. 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).

  7. 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)

  8. Metamaterial Receivers for High Efficiency Concentrated Solar Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Yellowhair, Julius E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Concentrating Solar Technologies Dept.; Kwon, Hoyeong [Univ. of Texas, Austin, TX (United States). Dept. of Electrical and Computer Engineering; Alu, Andrea [Univ. of Texas, Austin, TX (United States). Dept. of Electrical and Computer Engineering; Jarecki, Robert L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Concentrating Solar Technologies Dept.; Shinde, Subhash L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Concentrating Solar Technologies Dept.

    2016-09-01

    Operation of concentrated solar power receivers at higher temperatures (>700°C) would enable supercritical carbon dioxide (sCO2) power cycles for improved power cycle efficiencies (>50%) and cost-effective solar thermal power. Unfortunately, radiative losses at higher temperatures in conventional receivers can negatively impact the system efficiency gains. One approach to improve receiver thermal efficiency is to utilize selective coatings that enhance absorption across the visible solar spectrum while minimizing emission in the infrared to reduce radiative losses. Existing coatings, however, tend to degrade rapidly at elevated temperatures. In this report, we report on the initial designs and fabrication of spectrally selective metamaterial-based absorbers for high-temperature, high-thermal flux environments important for solarized sCO2 power cycles. Metamaterials are structured media whose optical properties are determined by sub-wavelength structural features instead of bulk material properties, providing unique solutions by decoupling the optical absorption spectrum from thermal stability requirements. The key enabling innovative concept proposed is the use of structured surfaces with spectral responses that can be tailored to optimize the absorption and retention of solar energy for a given temperature range. In this initial study through the Academic Alliance partnership with University of Texas at Austin, we use Tungsten for its stability in expected harsh environments, compatibility with microfabrication techniques, and required optical performance. Our goal is to tailor the optical properties for high (near unity) absorptivity across the majority of the solar spectrum and over a broad range of incidence angles, and at the same time achieve negligible absorptivity in the near infrared to optimize the energy absorbed and retained. To this goal, we apply the recently developed concept of plasmonic Brewster angle to suitably designed

  9. 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.

  10. Thermal energy storage for smart grid applications

    Science.gov (United States)

    Al-Hallaj, Said; Khateeb, Siddique; Aljehani, Ahmed; Pintar, Mike

    2018-01-01

    Energy consumption for commercial building cooling accounts for 15% of all commercial building's electricity usage [1]. Electric utility companies charge their customers time of use consumption charges (/kWh) and additionally demand usage charges (/kW) to limit peak energy consumption and offset their high operating costs. Thus, there is an economic incentive to reduce both the electricity consumption charges and demand charges by developing new energy efficient technologies. Thermal energy storage (TES) systems using a phase change material (PCM) is one such technology that can reduce demand charges and shift the demand from on-peak to off-peak rates. Ice and chilled water have been used in thermal storage systems for many decades, but they have certain limitations, which include a phase change temperature of 0 degrees Celsius and relatively low thermal conductivity in comparison to other materials, which limit their applications as a storage medium. To overcome these limitations, a novel phase change composite (PCC) TES material was developed that has much higher thermal conductivity that significantly improves the charge / discharge rate and a customizable phase change temperature to allow for better integration with HVAC systems. Compared to ice storage, the PCC TES system is capable of very high heat transfer rate and has lower system and operational costs. Economic analysis was performed to compare the PCC TES system with ice system and favorable economics was proven. A 4.5 kWh PCC TES prototype system was also designed for testing and validation purpose.

  11. Biogeochemical aspects of aquifer thermal energy storage

    NARCIS (Netherlands)

    Brons, H.J.

    1992-01-01

    During the process of aquifer thermal energy storage the in situ temperature of the groundwater- sediment system may fluctuate significantly. As a result the groundwater characteristics can be considerably affected by a variety of chemical, biogeochemical and microbiological

  12. Plasma thermal energy transport: theory and experiments

    International Nuclear Information System (INIS)

    Coppi, B.

    Experiments on the transport across the magnetic field of electron thermal energy are reviewed (Alcator, Frascati Torus). In order to explain the experimental results, a transport model is described that reconfirmed the need to have an expression for the local diffusion coefficient with a negative exponent of the electron temperature

  13. A Comprehensive Review of Thermal Energy Storage

    Directory of Open Access Journals (Sweden)

    Ioan Sarbu

    2018-01-01

    Full Text Available Thermal energy storage (TES is a technology that stocks thermal energy by heating or cooling a storage medium so that the stored energy can be used at a later time for heating and cooling applications and power generation. TES systems are used particularly in buildings and in industrial processes. This paper is focused on TES technologies that provide a way of valorizing solar heat and reducing the energy demand of buildings. The principles of several energy storage methods and calculation of storage capacities are described. Sensible heat storage technologies, including water tank, underground, and packed-bed storage methods, are briefly reviewed. Additionally, latent-heat storage systems associated with phase-change materials for use in solar heating/cooling of buildings, solar water heating, heat-pump systems, and concentrating solar power plants as well as thermo-chemical storage are discussed. Finally, cool thermal energy storage is also briefly reviewed and outstanding information on the performance and costs of TES systems are included.

  14. Energy Efficiency Enhancement of Photovoltaics by Phase Change Materials through Thermal Energy Recovery

    Directory of Open Access Journals (Sweden)

    Ahmad Hasan

    2016-09-01

    Full Text Available Photovoltaic (PV panels convert a certain amount of incident solar radiation into electricity, while the rest is converted to heat, leading to a temperature rise in the PV. This elevated temperature deteriorates the power output and induces structural degradation, resulting in reduced PV lifespan. One potential solution entails PV thermal management employing active and passive means. The traditional passive means are found to be largely ineffective, while active means are considered to be energy intensive. A passive thermal management system using phase change materials (PCMs can effectively limit PV temperature rises. The PCM-based approach however is cost inefficient unless the stored thermal energy is recovered effectively. The current article investigates a way to utilize the thermal energy stored in the PCM behind the PV for domestic water heating applications. The system is evaluated in the winter conditions of UAE to deliver heat during water heating demand periods. The proposed system achieved a ~1.3% increase in PV electrical conversion efficiency, along with the recovery of ~41% of the thermal energy compared to the incident solar radiation.

  15. 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.

  16. Controlled cellular energy conversion in brown adipose tissue thermogenesis

    Science.gov (United States)

    Horowitz, J. M.; Plant, R. E.

    1978-01-01

    Brown adipose tissue serves as a model system for nonshivering thermogenesis (NST) since a) it has as a primary physiological function the conversion of chemical energy to heat; and b) preliminary data from other tissues involved in NST (e.g., muscle) indicate that parallel mechanisms may be involved. Now that biochemical pathways have been proposed for brown fat thermogenesis, cellular models consistent with a thermodynamic representation can be formulated. Stated concisely, the thermogenic mechanism in a brown fat cell can be considered as an energy converter involving a sequence of cellular events controlled by signals over the autonomic nervous system. A thermodynamic description for NST is developed in terms of a nonisothermal system under steady-state conditions using network thermodynamics. Pathways simulated include mitochondrial ATP synthesis, a Na+/K+ membrane pump, and ionic diffusion through the adipocyte membrane.

  17. 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.

  18. 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...

  19. Wave loadings acting on Overtopping Breakwater for Energy Conversion

    DEFF Research Database (Denmark)

    Vicinanza, Diego; Nørgaard, Jørgen Harck; Contestabile, Pasquale

    2013-01-01

    distributions. Load measurements were compared with the most used prediction method for traditional breakwaters, available in the Coastal Engineering Manual (U.S. Army Corps of Engineers, 2002). These results suggest to use the experimental data as design loadings since the design criteria for the innovative......Any kind of Wave Energy Converter (WEC) requires information on reliability of technology and on time required for the return of the investment (reasonable payback). The structural response is one of the most important parameters to take in to account for a consistent assessment on innovative...... devices. This paper presents results on wave loading acting on an hybrid WEC named Overtopping BReakwater for Energy Conversion (OBREC). The new design is based on the concept of an integration between a traditional rubble mound breakwater and a front reservoir designed to store the wave overtopping from...

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. Plasmon-mediated Energy Conversion in Metal Nanoparticle-doped Hybrid Nanomaterials

    Science.gov (United States)

    Dunklin, Jeremy R.

    Climate change and population growth demand long-term solutions for clean water and energy. Plasmon-active nanomaterials offer a promising route towards improved energetics for efficient chemical separation and light harvesting schemes. Two material platforms featuring highly absorptive plasmonic gold nanoparticles (AuNPs) are advanced herein to maximize photon conversion into thermal or electronic energy. Optical extinction, attributable to diffraction-induced internal reflection, was enhanced up to 1.5-fold in three-dimensional polymer films containing AuNPs at interparticle separations approaching the resonant wavelength. Comprehensive methods developed to characterize heat dissipation following plasmonic absorption was extended beyond conventional optical and heat transfer descriptions, where good agreement was obtained between measured and estimated thermal profiles for AuNP-polymer dispersions. Concurrently, in situ reduction of AuNPs on two-dimensional semiconducting tungsten disulfide (WS2) addressed two current material limitations for efficient light harvesting: low monolayer content and lack of optoelectronic tunability. Order-of-magnitude increases in WS2 monolayer content, enhanced broadband optical extinction, and energetic electron injection were probed using a combination of spectroscopic techniques and continuum electromagnetic descriptions. Together, engineering these plasmon-mediated hybrid nanomaterials to facilitate local exchange of optical, thermal, and electronic energy supports design and implementation into several emerging sustainable water and energy applications.

  7. Temperature, salinity, and water chemistry data from quarterly surface transects of the Comprehensive Environmental Monitoring Program at the Ocean Thermal Energy Conversion plant in Keahole, Island of Hawaii 1993-2016 (NCEI Accession 0156452)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NATURAL ENERGY LABORATORY OF HAWAII AUTHORITY (NELHA) is a state agency that operates a unique and innovative ocean science and Technology park in Kailua-Kona on...

  8. Temperature, salinity, and water chemistry data from quarterly bottom transects of the Comprehensive Environmental Monitoring Program at the Ocean Thermal Energy Conversion plant in Keahole, Island of Hawaii 1993-2007 (NCEI Accession 0156980)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NATURAL ENERGY LABORATORY OF HAWAII AUTHORITY (NELHA) is a state agency that operates a unique and innovative ocean science and technology park in Kailua-Kona on...

  9. Temperature, salinity, and water chemistry data from the Comprehensive Environmental Monitoring Program of the Ocean Thermal Energy Conversion plant at Keahole, Island of Hawaii, from shallow and deep intake pipes during 1982-2016 (NODC Accession 0001623)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NATURAL ENERGY LABORATORY OF HAWAII AUTHORITY (NELHA) is a state agency that operates a unique and innovative ocean science and technology park in Kailua-Kona on...

  10. Precision measurements of high-energy conversion electron lines and determination of neutron binding energies

    International Nuclear Information System (INIS)

    Braumandl, F.

    1979-01-01

    The paper first discusses the energy accuracy of the BILL conversion electron spectrometer at the Grenoble high flux reactor. With an improved temperature stabilisation of the magnets, an energy accuracy of ΔE/E -5 can be reached. After this, highly exact measurements of high-energy conversion electron lines of the 200 Hg, 114 Cd, 165 Dy, 168 Er, 239 U nuclei and the 13 C, 28 Al 3 H and 92 Zr photoelectron lines were carried out. Energy calibration of the spectrometer was carried out in the 1.5 MeV to 6.5 MeV range with intensive high-energy transitions of the 200 Hg nucleus. Systematic calibration errors could be investigated by means of combinations between the calibration lines. A calibration for absolute energies was obtained by comparing low-energy gamma transitions of 200 Hg with the 411.8 keV gold standard. (orig.) [de

  11. Electronic and optical properties of doped oxides for energy conversion

    International Nuclear Information System (INIS)

    Silva, Antonio Ferreira da

    2016-01-01

    Full text: Photocatalytic materials have gained remarkable attention in the field of solar fuel production, which is a promising approach for efficient solar energy conversion and storage . Among other oxides, doped BiNb(Ta)O 4 , ZnO , SnO 2 , WO 3 and TiO 2 have been identified as potential photocatalytic materials due to their appropriate band gap energies. We have used high quality materials as for instance by the citrate method according to reference [1], a modified ion beam assisted deposition technique [2] and as titanium dioxide nanotubes (TiO 2 -NTs) arrays synthesized by electrochemical anodization [3]. We present the optical properties spectra of these materials using the X-ray Photoelectron Spectroscopy (XPS), Ellipsometry and first principles approach by DFT respectively [1,2]. In this work, position of reduction and oxidation level with respect to the vacuum level are identified for these materials. We can conclude that some of them are good candidates for the production of hydrogen by splitting of water in the presence of sunlight and for efficient solar energy conversion as well. [1] C. G. Almeida, R. B. Araujo, R. G. Yoshimura, A. J. S. Mascarenhas, A. Ferreira da Silva, C. M.Araujo, L. A. Silva,Int. J. Hyd. Energy 39, 1220 (2014). [2] M. Kumar, G.Baldissera, C.Persson, D.G.F.David ,M.V.S.da Silva , J.A.Freitas Jr., J.G. Tischler , J.F.D.Chubaci, M.Matsuoka , A.Ferreira da Silva, , J. of Crystal Growth 403, 124 (2014). [3] J. R. Gonzalez et all., Nanotechnology (2016 in press). (author)

  12. Electronic and optical properties of doped oxides for energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Antonio Ferreira da, E-mail: ferreira.fis@gmail.com [Universidade Federal da Bahia (UFBA), Salvador (Brazil)

    2016-07-01

    Full text: Photocatalytic materials have gained remarkable attention in the field of solar fuel production, which is a promising approach for efficient solar energy conversion and storage . Among other oxides, doped BiNb(Ta)O{sub 4}, ZnO , SnO{sub 2}, WO{sub 3} and TiO{sub 2} have been identified as potential photocatalytic materials due to their appropriate band gap energies. We have used high quality materials as for instance by the citrate method according to reference [1], a modified ion beam assisted deposition technique [2] and as titanium dioxide nanotubes (TiO{sub 2}-NTs) arrays synthesized by electrochemical anodization [3]. We present the optical properties spectra of these materials using the X-ray Photoelectron Spectroscopy (XPS), Ellipsometry and first principles approach by DFT respectively [1,2]. In this work, position of reduction and oxidation level with respect to the vacuum level are identified for these materials. We can conclude that some of them are good candidates for the production of hydrogen by splitting of water in the presence of sunlight and for efficient solar energy conversion as well. [1] C. G. Almeida, R. B. Araujo, R. G. Yoshimura, A. J. S. Mascarenhas, A. Ferreira da Silva, C. M.Araujo, L. A. Silva,Int. J. Hyd. Energy 39, 1220 (2014). [2] M. Kumar, G.Baldissera, C.Persson, D.G.F.David ,M.V.S.da Silva , J.A.Freitas Jr., J.G. Tischler , J.F.D.Chubaci, M.Matsuoka , A.Ferreira da Silva, , J. of Crystal Growth 403, 124 (2014). [3] J. R. Gonzalez et all., Nanotechnology (2016 in press). (author)

  13. Thermal Characteristics of Conversion-Type FeOF Cathode in Li-ion Batteries

    Directory of Open Access Journals (Sweden)

    Liwei Zhao

    2017-10-01

    Full Text Available Rutile FeOF was used as a conversion-type cathode material for Li-ion batteries. In the present study, 0.6Li, 1.4Li, and 2.7Li per mole lithiation reactions were carried out by changing the electrochemical discharge reaction depth. The thermal characteristics of the FeOF cathode were investigated by thermogravimetric mass spectrometric (TG-MS and differential scanning calorimeter (DSC systems. No remarkable HF release was detected, even up to 700 °C, which indicated a low toxic risk for the FeOF cathode. Changes in the thermal properties of the FeOF cathode via different conversion reaction depths in the associated electrolyte were studied by changing the cathode/electrolyte ratio in the mixture. LiFeOF was found to exothermically react with the electrolyte at about 210 °C. Similar exothermic reactions were found with charged FeOF cathodes because of the irreversible Li ions. Among the products of the conversion reaction of FeOF, Li2O was found to exothermically react with the electrolyte at about 120 °C, which induced the main thermal risk of the FeOF cathode. It suggests that the oxygen-containing conversion-type cathodes have a higher thermal risk than the oxygen-free ones, but controlling the cathode/electrolyte ratio in cells successfully reduced the thermal risk. Finally, the thermal stability of the FeOF cathode was evaluated in comparison with FeF3 and LiFePO4 cathodes.

  14. Energy Address Delivery Technologies and Thermal Transformations in Food Production

    Directory of Open Access Journals (Sweden)

    Burdo O.G.

    2016-08-01

    Full Text Available In this article, energetic and technical paradoxes in food nanotechnologies and traditional approaches to evaluation of energy recourses using are considered. Hypotheses of improvement of food production energy technologies are formulated. Classification of principles of address delivery of energy to food raw materials elements is given. We had substantiated the perspective objectives for heat-pumps installations and biphasic heat-transfer systems. The energy efficiency of new technolo-gies is compared on base of the number of energy impact. Principles of mass transfer modeling in ex-traction, dehydration and pasteurization combined processes are considered by food production exam-ple. The objectives of mathematical modeling of combined hydrodynamic and heat and mass transfer processes in modern energy technologies are set. The fuel energy conversion diagrams for drying, in-novative installations on the base of thermal siphons, heat pumps and electromagnetic energy genera-tors are represented. In this article, we illustrate how electromagnetic field, biphasic heat-transfer sys-tems and heat pumps can be effective tools for energy efficiency technologies.

  15. 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.

  16. Efficient energy conversion in the pulp and paper industry

    Energy Technology Data Exchange (ETDEWEB)

    Marechal, F.; Perin-Levasseur, Z.

    2005-07-01

    This yearly report for the Swiss Federal Office of Energy (SFOE) takes a look at the work done in 2005 and the work planned for 2006 within the framework of the Efficient Energy Conversion in the Pulp and Paper Industry project. The results of investigations made at a large pulp and paper facility in Switzerland are presented and analysed. Data models of the steam and condensate networks and of the processes involved are examined. An additional model of the sulphur loop has been also elaborated. From this analysis, a list of required measurements has been developed. Several performance indicators have also been calculated: A systematic analysis method developed to identify sections where condensate could be recovered is discussed. A systematic definition of the hot and cold streams in the process is being developed in order to compute the minimum energy requirements of the process. Evaluating this minimum energy requirement from the data available is to be used to prepare definitions of the energy savings possible.

  17. 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.

  18. Semi-flexible bimetal-based thermal energy harvesters

    International Nuclear Information System (INIS)

    Boisseau, S; Despesse, G; Monfray, S; Puscasu, O; Skotnicki, T

    2013-01-01

    This paper introduces a new semi-flexible device able to turn thermal gradients into electricity by using a curved bimetal coupled to an electret-based converter. In fact, a two-step conversion is carried out: (i) a curved bimetal turns the thermal gradient into a mechanical oscillation that is then (ii) converted into electricity thanks to an electrostatic converter using electrets in Teflon ® . The semi-flexible and low-cost design of these new energy converters pave the way to mass production over large areas of thermal energy harvesters. Raw output powers up to 13.46 μW per device were reached on a hot source at 60 °C with forced convection. Then, a DC-to-DC flyback converter has been sized to turn the energy harvesters’ raw output powers into a viable supply source for an electronic circuit (DC-3 V). At the end, 10 μW of directly usable output power were reached with 3 devices, which is compatible with wireless sensor network powering applications. (paper)

  19. Ocean thermal energy: concept and resources, history and perspectives

    International Nuclear Information System (INIS)

    Nihous, Gerard

    2015-10-01

    Two articles address the possibility of exploiting a higher than 20 degrees temperature difference between ocean surfaces and 1 km deep waters to produce electricity. The first article describes the operation principle in closed cycle and briefly presents the open cycle approach. The global energetic assessment is discussed. The author analyses available thermal resources in relationship with the main ocean streams. He outlines that the design of an ocean thermal energy project requires the acquisition and knowledge of a lot of data, modelling and simulations. In the second article, the author notices that past experiments highlighted the difficulties of implementation of the concept. He notably evokes works performed by Georges Claude during the 1920's, projects elaborated at the end of the 20. century, the realisation of a mini OTEC (Ocean Thermal Energy Conversion) station in Hawaii, the OTEC-1 project, a Japanese project in Nauru, the test of a suspended cold water duct, the net power producing experiment in the USA. Perspectives and costs are finally briefly discussed, and recent and promising projects briefly evoked (notably that by DCNS and Akuo Energy in Martinique)

  20. Thermal Energy Storage with Phase Change Material

    Directory of Open Access Journals (Sweden)

    Lavinia Gabriela SOCACIU

    2012-08-01

    Full Text Available Thermal energy storage (TES systems provide several alternatives for efficient energy use and conservation. Phase change materials (PCMs for TES are materials supplying thermal regulation at particular phase change temperatures by absorbing and emitting the heat of the medium. TES in general and PCMs in particular, have been a main topic in research for the last 30 years, but although the information is quantitatively enormous, it is also spread widely in the literature, and difficult to find. PCMs absorb energy during the heating process as phase change takes place and release energy to the environment in the phase change range during a reverse cooling process. PCMs possesses the ability of latent thermal energy change their state with a certain temperature. PCMs for TES are generally solid-liquid phase change materials and therefore they need encapsulation. TES systems using PCMs as a storage medium offers advantages such as high TES capacity, small unit size and isothermal behaviour during charging and discharging when compared to the sensible TES.

  1. Aquifer thermal energy stores in Germany

    International Nuclear Information System (INIS)

    Kabus, F.; Seibt, P.; Poppei, J.

    2000-01-01

    This paper describes the state of essential demonstration projects of heat and cold storage in aquifers in Germany. Into the energy supply system of the buildings of the German Parliament in Berlin, there are integrated both a deep brine-bearing aquifer for the seasonal storage of waste heat from power and heat cogeneration and a shallow-freshwater bearing aquifer for cold storage. In Neubrandenburg, a geothermal heating plant which uses a 1.200 m deep aquifer is being retrofitted into an aquifer heat storage system which can be charged with the waste heat from a gas and steam cogeneration plant. The first centralised solar heating plant including an aquifer thermal energy store in Germany was constructed in Rostock. Solar collectors with a total area of 1000m 2 serve for the heating of a complex of buildings with 108 flats. A shallow freshwater-bearing aquifer is used for thermal energy storage. (Authors)

  2. SOLID STATE ENERGY CONVERSION ALLIANCE (SECA) SOLID OXIDE FUEL CELL PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Minh; Jim Powers

    2003-10-01

    This report summarizes the work performed for April 2003--September 2003 reporting period under Cooperative Agreement DE-FC26-01NT41245 for the U.S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid State Energy Conversion Alliance (SECA) Solid oxide Fuel Cell Program''. During this reporting period, the conceptual system design activity was completed. The system design, including strategies for startup, normal operation and shutdown, was defined. Sealant and stack materials for the solid oxide fuel cell (SOFC) stack were identified which are capable of meeting the thermal cycling and degradation requirements. A cell module was tested which achieved a stable performance of 0.238 W/cm{sup 2} at 95% fuel utilization. The external fuel processor design was completed and fabrication begun. Several other advances were made on various aspects of the SOFC system, which are detailed in this report.

  3. Technical and economic assessment of energy conversion technologies for MSW

    Energy Technology Data Exchange (ETDEWEB)

    Livingston, W.R.

    2002-07-01

    Thermal processes for municipal solid wastes (MSW) based on pyrolysis and/or gasification that have relevance to the emerging UK market are described in this report, and the results of the technical and economical assessment of these processes are presented. The Mitsui R21 Technology, the Thermoselect Process, the Nippon Steel Waste Melting Process, the Pyropleq Process, and the Compact Power Process are selected for detailed comparison on the basis of the overall technical concept, the energy balance and the requirements for consumables, environmental performance, and the technical and commercial status of the technology. Details are also given of a comparison of the novel thermal technologies with conventional mass burn incineration for MSW.

  4. Technical and economic assessment of energy conversion technologies for MSW

    International Nuclear Information System (INIS)

    Livingston, W.R.

    2002-01-01

    Thermal processes for municipal solid wastes (MSW) based on pyrolysis and/or gasification that have relevance to the emerging UK market are described in this report, and the results of the technical and economical assessment of these processes are presented. The Mitsui R21 Technology, the Thermoselect Process, the Nippon Steel Waste Melting Process, the Pyropleq Process, and the Compact Power Process are selected for detailed comparison on the basis of the overall technical concept, the energy balance and the requirements for consumables, environmental performance, and the technical and commercial status of the technology. Details are also given of a comparison of the novel thermal technologies with conventional mass burn incineration for MSW

  5. Utilization of salt ammoniacates in fluidized beds in energy conversion thermochemical systems

    International Nuclear Information System (INIS)

    Romero, Jesus

    1984-01-01

    This research thesis notably reports the design and development of a thermochemical storage device involving equilibria of thermal decomposition of ammoniacates of strontium chlorides and calcium chloride in fluidized beds. The experimental study of this device allowed operating conditions and the most important concomitant effects of fluidization to be highlighted. The measured thermal exchange coefficient is about twenty times the measured value in equivalent devices using fixed beds. An irreversibility of the operation has been noticed, and seems to be associated with the irreversible change of grain size of solids. The author also reports a study of the properties of ammoniacates of metallic salts, and of the influence of fluidization on the performance of energy conversion thermochemical systems [fr

  6. 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.

  7. 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

  8. Improvements to thermal plants for generating energy

    International Nuclear Information System (INIS)

    Pacault, P.H.

    1975-01-01

    Said invention relates to a procedure for superheating steam intended for steam cycled thermal plants of energy production, and particularly nuclear power plants. Said procedure combines two different working modes. According to the first working mode, the live steam is taken from the steam generator, mechanically compressed and the heat is partly transferred to the working fluid. According to the second working mode the heat is taken from an auxiliary fluid heated by an independent thermal source, distinct from the principal thermal source of the plant and this heat is partly transferred to the working fluid. A combination of both working modes enables the superheating of the working fluid to be obtained before it inflows the turbine and/or between two stages of said turbine [fr

  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. Parametric study on thermal-hydraulic characteristics of high conversion light water reactor

    International Nuclear Information System (INIS)

    Mori, Takamasa; Nakagawa, Masayuki; Fujii, Sadao.

    1988-11-01

    To assess the feasibility of high conversion light water reactors (HCLWRs) from the thermal-hydraulic viewpoint, parametric study on thermal-hydraulic characteristics of HCLWR has been carried out by using a unit cell model. It is assumed that a HCLWR core is contained in a current 1000 MWe PWR plant. At the present study, reactor core parameters such as fuel pin diameter, pitch, core height and linear heat rate are widely and parametrically changed to survey the relation between these parameters and the basic thermal-hydraulic characteristics, i.e. maximum fuel temperature, minimum DNBR, reduction of reactor thermal output and so on. The validity of the unit cell model used has been ensured by comparison with the result of a subchannel analysis carried out for a whole core. (author)

  11. Operational Experience from Solar Thermal Energy Projects

    Science.gov (United States)

    Cameron, C. P.

    1984-01-01

    Over the past few years, Sandia National Laboratories were involved in the design, construction, and operation of a number of DOE-sponsored solar thermal energy systems. Among the systems currently in operation are several industrial process heat projects and the Modular Industrial Solar Retrofit qualification test systems, all of which use parabolic troughs, and the Shenandoah Total Energy Project, which uses parabolic dishes. Operational experience has provided insight to both desirable and undesirable features of the designs of these systems. Features of these systems which are also relevant to the design of parabolic concentrator thermal electric systems are discussed. Other design features discussed are system control functions which were found to be especially convenient or effective, such as local concentrator controls, rainwash controls, and system response to changing isolation. Drive systems are also discussed with particular emphasis of the need for reliability and the usefulness of a manual drive capability.

  12. Life cycle integrated thermoeconomic assessment method for energy conversion systems

    International Nuclear Information System (INIS)

    Kanbur, Baris Burak; Xiang, Liming; Dubey, Swapnil; Choo, Fook Hoong; Duan, Fei

    2017-01-01

    Highlights: • A new LCA integrated thermoeconomic approach is presented. • The new unit fuel cost is found 4.8 times higher than the classic method. • The new defined parameter increased the sustainability index by 67.1%. • The case studies are performed for countries with different CO 2 prices. - Abstract: Life cycle assessment (LCA) based thermoeconomic modelling has been applied for the evaluation of energy conversion systems since it provided more comprehensive and applicable assessment criteria. This study proposes an improved thermoeconomic method, named as life cycle integrated thermoeconomic assessment (LCiTA), which combines the LCA based enviroeconomic parameters in the production steps of the system components and fuel with the conventional thermoeconomic method for the energy conversion systems. A micro-cogeneration system is investigated and analyzed with the LCiTA method, the comparative studies show that the unit cost of fuel by using the LCiTA method is 3.8 times higher than the conventional thermoeconomic model. It is also realized that the enviroeconomic parameters during the operation of the system components do not have significant impacts on the system streams since the exergetic parameters are dominant in the thermoeconomic calculations. Moreover, the improved sustainability index is found roundly 67.2% higher than the previously defined sustainability index, suggesting that the enviroeconomic and thermoeconomic parameters decrease the impact of the exergy destruction in the sustainability index definition. To find the feasible operation conditions for the micro-cogeneration system, different assessment strategies are presented. Furthermore, a case study for Singapore is conducted to see the impact of the forecasted carbon dioxide prices on the thermoeconomic performance of the micro-cogeneration system.

  13. 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.

  14. 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.

  15. 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.

  16. Special conference on thermal energy 'Yugoslavia 1986'

    International Nuclear Information System (INIS)

    1986-01-01

    This volume contains various papers held at the conference 'Thermoenergetica 1986'. The papers cover subjects ranging from the development of thermal energy in Yugoslavia via fluidized-bed combustion and experience gained with the construction and operation of coal-fuelled plants to the grinding and combustion of coals rich in inerts, pollution problems, fouling and slag formation, service life, stress-induced crack corrosions, and to the planning, construction and operation of nuclear power plants. (HAG) [de

  17. 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.

  18. 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.

  19. The direct conversion of solar energy to electricity

    International Nuclear Information System (INIS)

    1992-01-01

    Half the world's population lives without access to electricity in the rural areas and villages of developing countries. In 1987, world population reached 5 billion and, according to World Bank projections, will increase to over 6 billion in the year 2000 and to over 8 billion in 2025. Such population growth is not uniformly distributed: developed countries have small or negative growth and account for a declining proportion of the world's population. Inasmuch as 95 per cent of the extra inhabitants added each year are in developing countries, rapid population growth in those countries raises serious questions about energy availability for basic human needs and, of course, more broadly about the environment's capacity to support that growth. The present report makes reference to one of the most comprehensively documented conservative scenarios for world energy demand in the year 2020, namely, Energy for a Sustainable World, which assumed that long-term world sustainability must entail constraints on (a) use of natural resources and (b) combustion of fossil fuels resulting in the greenhouse effect. Solar energy is abundant and could become a major source of electricity. Photovoltaics has three particular advantages. It accomplishes sunlight-to-electricity conversion entirely with solid-state electronic components, and with no moving parts required, thereby promising high equipment availability and very low operating and maintenance costs. PV also appears to have very limited environmental impact, with no emissions of the gaseous pollutants associated with fossil-fuel burning and few of the possible local problems associated with some other renewable energy technologies. Finally, the products of photovoltaic technology are modular in construction and can be built up on site in a flexible way, thus minimizing front-end financial risk and investment costs. Figs and tabs

  20. Recouping the thermal-to-electric conversion loss by the use of waste heat

    International Nuclear Information System (INIS)

    Bradley, W.J.

    1976-01-01

    This paper looks at ways to recoup the thermal-to-electric conversion loss of our thermal power generating stations. These stations now produce twice as much low-grade waste heat as they do electricity. We can improve the situation in two ways: by improving the station efficiency, and by utilizing the low-grade heat beneficially. The following options are examined: N 2 O 4 turbines condensing at 10 deg C; power from moderator waste heat; 50 MW heat pump for district heating; industrial parks with integrated waste heat upgrading station. (author)

  1. Thermal Distribution System | Energy Systems Integration Facility | NREL

    Science.gov (United States)

    Thermal Distribution System Thermal Distribution System The Energy Systems Integration Facility's . Photo of the roof of the Energy Systems Integration Facility. The thermal distribution bus allows low as 10% of its full load level). The 60-ton chiller cools water with continuous thermal control

  2. Graphene-based electrochemical energy conversion and storage: fuel cells, supercapacitors and lithium ion batteries.

    Science.gov (United States)

    Hou, Junbo; Shao, Yuyan; Ellis, Michael W; Moore, Robert B; Yi, Baolian

    2011-09-14

    Graphene has attracted extensive research interest due to its strictly 2-dimensional (2D) structure, which results in its unique electronic, thermal, mechanical, and chemical properties and potential technical applications. These remarkable characteristics of graphene, along with the inherent benefits of a carbon material, make it a promising candidate for application in electrochemical energy devices. This article reviews the methods of graphene preparation, introduces the unique electrochemical behavior of graphene, and summarizes the recent research and development on graphene-based fuel cells, supercapacitors and lithium ion batteries. In addition, promising areas are identified for the future development of graphene-based materials in electrochemical energy conversion and storage systems. This journal is © the Owner Societies 2011

  3. Efficiency gains of photovoltaic system using latent heat thermal energy storage

    NARCIS (Netherlands)

    Tan, Lippong; Date, Abhijit; Fernandes, Gabriel; Singh, Baljit; Ganguly, Sayantan

    This paper presents experimental assessments of the thermal and electrical performance of photovoltaic (PV) system by comparing the latent heat-cooled PV panel with the naturally-cooled equivalent. It is commonly known that the energy conversion efficiency of the PV cells declines with the increment

  4. Energy loss and thermalization of low-energy electrons

    International Nuclear Information System (INIS)

    LaVerne, J.A.; Mozumder, A.; Notre Dame Univ., IN

    1984-01-01

    Various processes involved in the moderation of low-energy electrons (< 10 keV in energy) have been delineated in gaseous and liquid media. The discussion proceeds in two stages. The first stage ends and the second stage begins when the electron energy equals the first excitation potential of the medium. The second stage ends with thermalization. Cross sections for electronic excitation and for the excitation (and de-excitation) of sub-electronic processes have been evaluated and incorporated in suitable stopping power and transport theories. Comparison between experiment and theory and intercomparisons between theories and experiments have been provided where possible. (author)

  5. 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.

  6. High temperature underground thermal energy storage system for solar energy

    Science.gov (United States)

    Collins, R. E.

    1980-01-01

    The activities feasibility of high temperature underground thermal storage of energy was investigated. Results indicate that salt cavern storage of hot oil is both technically and economically feasible as a method of storing huge quantities of heat at relatively low cost. One particular system identified utilizes a gravel filled cavern leached within a salt dome. Thermal losses are shown to be less than one percent of cyclically transferred heat. A system like this having a 40 MW sub t transfer rate capability and over eight hours of storage capacity is shown to cost about $13.50 per KWh sub t.

  7. 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)

  8. Diurnal Solar Energy Conversion and Photoprotection in Rice Canopies.

    Science.gov (United States)

    Meacham, Katherine; Sirault, Xavier; Quick, W Paul; von Caemmerer, Susanne; Furbank, Robert

    2017-01-01

    Genetic improvement of photosynthetic performance of cereal crops and increasing the efficiency with which solar radiation is converted into biomass has recently become a major focus for crop physiologists and breeders. The pulse amplitude modulated chlorophyll fluorescence technique (PAM) allows quantitative leaf level monitoring of the utilization of energy for photochemical light conversion and photoprotection in natural environments, potentially over the entire crop lifecycle. Here, the diurnal relationship between electron transport rate (ETR) and irradiance was measured in five cultivars of rice (Oryza sativa) in canopy conditions with PAM fluorescence under natural solar radiation. This relationship differed substantially from that observed for conventional short term light response curves measured under controlled actinic light with the same leaves. This difference was characterized by a reduced curvature factor when curve fitting was used to model this diurnal response. The engagement of photoprotective processes in chloroplast electron transport in leaves under canopy solar radiation was shown to be a major contributor to this difference. Genotypic variation in the irradiance at which energy flux into photoprotective dissipation became greater than ETR was observed. Cultivars capable of higher ETR at midrange light intensities were shown to produce greater leaf area over time, estimated by noninvasive imaging. © 2017 American Society of Plant Biologists. All Rights Reserved.

  9. High-Resolution Measurements of Low-Energy Conversion Electrons

    CERN Multimedia

    Gizon, A; Putaux, J

    2002-01-01

    Measurements of low-energy internal conversion electrons have been performed with high energy resolution in some N = 105 odd and odd-odd nuclei using a semi-circular spectrograph associated to a specific tape transport system. These experiments aimed to answer the following questions~: \\begin{itemize} \\item Do M3 isomeric transitions exist in $^{183}$Pt and $^{181}$Os, isotones of $^{184}$Au~? \\item Are the neutron configurations proposed to describe the isomeric and ground states of $^{184}$Au right or wrong~? \\item Does it exist an isomeric state in $^{182}$Ir, isotone of $^{181}$Os, $^{183}$Pt and $^{184}$Au~? \\item What are the spin and parity values of the excited states of $^{182}$Ir~? \\end{itemize} In $^{183}$Pt, the 35.0 keV M3 isomeric transition has been clearly observed and the reduced transition probability has been determined. The deduced hindrance factor is close to that observed in the neighbouring odd-odd $^{184}$Au nucleus. This confirms the neutron configurations previously proposed for the ...

  10. Significant thermal energy reduction in lactic acid production process

    International Nuclear Information System (INIS)

    Mujtaba, Iqbal M.; Edreder, Elmahboub A.; Emtir, Mansour

    2012-01-01

    Lactic acid is widely used as a raw material for the production of biodegradable polymers and in food, chemical and pharmaceutical industries. The global market for lactic acid is expected to reach 259 thousand metric tons by the year 2012. For batch production of lactic acid, the traditional process includes the following steps: (i) esterification of impure lactic acid with methanol in a batch reactor to obtain methyl lactate (ester), (ii) separation of the ester in a batch distillation, (iii) hydrolysis of the ester with water in a batch reactor to produce lactic acid and (iv) separation of lactic acid (in high purity) in a batch distillation. Batch reactive distillation combines the benefit of both batch reactor and batch distillation and enhances conversion and productivity (Taylor and Krishna, 2000 ; Mujtaba and Macchietto, 1997 ). Therefore, the first and the last two steps of the lactic acid production process can be combined together in batch reactive distillation () processes. However, distillation (batch or continuous) is an energy intensive process and consumes large amount of thermal energy (via steam). This paper highlights how significant (over 50%) reduction in thermal energy consumption can be achieved for lactic acid production process by carefully controlling the reflux ratio but without compromising the product specification. In this paper, only the simultaneous hydrolysis of methyl lactate ester and the separation of lactic acid using batch reactive distillation is considered.

  11. A theoretical analysis of price elasticity of energy demand in multistage energy conversion systems

    International Nuclear Information System (INIS)

    Lowe, R.

    2003-01-01

    The objective of this paper is an analytical exploration of the problem of price elasticity of energy demand in multi-stage energy conversion systems. The paper describes in some detail an analytical model of energy demand in such systems. Under a clearly stated set of assumptions, the model makes it possible to explore both the impacts of the number of sub-systems, and of varying sub-system elasticities on overall system elasticity. The analysis suggests that overall price elasticity of energy demand for such systems will tend asymptotically to unity as the number of sub-systems increases. (author)

  12. A theoretical analysis of price elasticity of energy demand in multi-stage energy conversion systems

    International Nuclear Information System (INIS)

    Lowe, Robert

    2003-01-01

    The objective of this paper is an analytical exploration of the problem of price elasticity of energy demand in multi-stage energy conversion systems. The paper describes in some detail an analytical model of energy demand in such systems. Under a clearly stated set of assumptions, the model makes it possible to explore both the impacts of the number of sub-systems, and of varying sub-system elasticities on overall system elasticity. The analysis suggests that overall price elasticity of energy demand for such systems will tend asymptotically to unity as the number of sub-systems increases

  13. What limits photosynthetic energy conversion efficiency in nature? Lessons from the oceans.

    Science.gov (United States)

    Falkowski, Paul G; Lin, Hanzhi; Gorbunov, Maxim Y

    2017-09-26

    Constraining photosynthetic energy conversion efficiency in nature is challenging. In principle, two yield measurements must be made simultaneously: photochemistry, fluorescence and/or thermal dissipation. We constructed two different, extremely sensitive and precise active fluorometers: one measures the quantum yield of photochemistry from changes in variable fluorescence, the other measures fluorescence lifetimes in the picosecond time domain. By deploying the pair of instruments on eight transoceanic cruises over six years, we obtained over 200 000 measurements of fluorescence yields and lifetimes from surface waters in five ocean basins. Our results revealed that the average quantum yield of photochemistry was approximately 0.35 while the average quantum yield of fluorescence was approximately 0.07. Thus, closure on the energy budget suggests that, on average, approximately 58% of the photons absorbed by phytoplankton in the world oceans are dissipated as heat. This extraordinary inefficiency is associated with the paucity of nutrients in the upper ocean, especially dissolved inorganic nitrogen and iron. Our results strongly suggest that, in nature, most of the time, most of the phytoplankton community operates at approximately half of its maximal photosynthetic energy conversion efficiency because nutrients limit the synthesis or function of essential components in the photosynthetic apparatus.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'. © 2017 The Author(s).

  14. Conversion, core redesign and upgrade of the Rhode Island Atomic Energy Commission Reactor

    International Nuclear Information System (INIS)

    DiMeglio, A.F.

    1987-01-01

    The 2 MW Rhode Island Atomic Energy Commission reactor is required to convert from the use of High Enriched Uranium (HEU) fuel to the use of Low Enriched Uranium (LEU) fuel using a standard LEU fuel plate which is thinner and contains more Uranium-235 than the current HEU plate. These differences, coupled with the fact that the conversion should be accomplished without serious degradation of reactor characteristics and capability, has resulted in core design studies and thermal hydraulic studies not only at the current 2 MW but also at the maximum power level of the reactor, 5 MW. In addition, during the course of its 23 years of operation, it has become clear that the main uses of the reactor are neutron scattering and neutron activation analysis. The requirement to convert to LEU presents an opportunity during the conversion to optimize the core for the utilization and to restudy the thermal hydraulics using modern techniques. This paper will present the preliminary conclusions of both aspects. (Author)

  15. Methods for locating ground faults and insulation degradation condition in energy conversion systems

    Science.gov (United States)

    Agamy, Mohamed; Elasser, Ahmed; Galbraith, Anthony William; Harfman Todorovic, Maja

    2015-08-11

    Methods for determining a ground fault or insulation degradation condition within energy conversion systems are described. A method for determining a ground fault within an energy conversion system may include, in part, a comparison of baseline waveform of differential current to a waveform of differential current during operation for a plurality of DC current carrying conductors in an energy conversion system. A method for determining insulation degradation within an energy conversion system may include, in part, a comparison of baseline frequency spectra of differential current to a frequency spectra of differential current transient at start-up for a plurality of DC current carrying conductors in an energy conversion system. In one embodiment, the energy conversion system may be a photovoltaic system.

  16. Aquifer thermal-energy-storage modeling

    Science.gov (United States)

    Schaetzle, W. J.; Lecroy, J. E.

    1982-09-01

    A model aquifer was constructed to simulate the operation of a full size aquifer. Instrumentation to evaluate the water flow and thermal energy storage was installed in the system. Numerous runs injecting warm water into a preconditioned uniform aquifer were made. Energy recoveries were evaluated and agree with comparisons of other limited available data. The model aquifer is simulated in a swimming pool, 18 ft by 4 ft, which was filled with sand. Temperature probes were installed in the system. A 2 ft thick aquifer is confined by two layers of polyethylene. Both the aquifer and overburden are sand. Four well configurations are available. The system description and original tests, including energy recovery, are described.

  17. ECUT (Energy Conversion and Utilization Technologies) program: Biocatalysis project

    Science.gov (United States)

    Baresi, Larry

    1989-03-01

    The Annual Report presents the fiscal year (FY) 1988 research activities and accomplishments, for the Biocatalysis Project of the U.S. Department of Energy, Energy Conversion and Utilization Technologies (ECUT) Division. The ECUT Biocatalysis Project is managed by the Jet Propulsion Laboratory, California Institute of Technology. The Biocatalysis Project is a mission-oriented, applied research and exploratory development activity directed toward resolution of the major generic technical barriers that impede the development of biologically catalyzed commercial chemical production. The approach toward achieving project objectives involves an integrated participation of universities, industrial companies and government research laboratories. The Project's technical activities were organized into three work elements: (1) The Molecular Modeling and Applied Genetics work element includes research on modeling of biological systems, developing rigorous methods for the prediction of three-dimensional (tertiary) protein structure from the amino acid sequence (primary structure) for designing new biocatalysis, defining kinetic models of biocatalyst reactivity, and developing genetically engineered solutions to the generic technical barriers that preclude widespread application of biocatalysis. (2) The Bioprocess Engineering work element supports efforts in novel bioreactor concepts that are likely to lead to substantially higher levels of reactor productivity, product yields and lower separation energetics. Results of work within this work element will be used to establish the technical feasibility of critical bioprocess monitoring and control subsystems. (3) The Bioprocess Design and Assessment work element attempts to develop procedures (via user-friendly computer software) for assessing the energy-economics of biocatalyzed chemical production processes, and initiation of technology transfer for advanced bioprocesses.

  18. 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

  19. Micro thermal energy harvester design optimization

    International Nuclear Information System (INIS)

    Trioux, E; Basrour, S; Monfray, S

    2017-01-01

    This paper reports the recent progress of a new technology to scavenge thermal energy, implying a double-step transduction through the thermal buckling of a bilayer aluminum nitride/aluminum bridge and piezoelectric transduction. A completely new scavenger design is presented, with improved performance. The butterfly shape reduces the overall device mechanical rigidity, which leads to a decrease in buckling temperatures compared to previously studied rectangular plates. Firstly, an analytical model exposes the basic principle of the presented device. Then a numerical model completes the explanations by introducing a butterfly shaped structure. Finally the fabrication process is briefly described and both the rectangular and butterfly harvesters are characterized. We compare their performances with an equal thickness of Al and AlN. Secondly, with a thicker Al layer than AlN layer, we will characterize only the butterfly structure in terms of output power and buckling temperatures, and compare it to the previous stack. (paper)

  20. Conversion of gravity field energy. Konversion von Schwerkraft-Feld-Energie

    Energy Technology Data Exchange (ETDEWEB)

    Nieper, H A

    1981-01-01

    This book by Mittelstandsinstitut Niedersachsen is a proceedings volume on the conference on energy technology on November 27/28, 1980. The meeting was attended by about 360 persons. On the basis of the knowledge presented, conversion of tachyon field energy into useful electrical energy appears possible. The tachyon field is present everywhere in space. Seike estimated its field strength at 8.8 x 10/sup 8/ V/cm. Magnetic and electrostatic fields can intercept tachyon energy. Especially masses subject to strong magnetic induction take up much tachyon energy. Also abrupt changes of voltage seem to extract energy from tachyons. The Gray motor is based on this principle. Further devices taking energy from the tachyon field are presented, e.g. the Johnson motor which has recently been given the Pat. No. US 4 151 431.