WorldWideScience

Sample records for biomimetic energy conversion

  1. Approaches for biological and biomimetic energy conversion

    OpenAIRE

    LaVan, David A.; Cha, Jennifer N.

    2006-01-01

    This article highlights areas of research at the interface of nanotechnology, the physical sciences, and biology that are related to energy conversion: specifically, those related to photovoltaic applications. Although much ongoing work is seeking to understand basic processes of photosynthesis and chemical conversion, such as light harvesting, electron transfer, and ion transport, application of this knowledge to the development of fully synthetic and/or hybrid devices is still in its infanc...

  2. 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.

  3. Green Tribology Biomimetics, Energy Conservation and Sustainability

    CERN Document Server

    Bhushan, Bharat

    2012-01-01

    Tribology is the study of friction, wear and lubrication. Recently, the concept of “green tribology” as “the science and technology of the tribological aspects of ecological balance and of environmental and biological impacts” was introduced. The field of green tribology includes tribological technology that mimics living nature (biomimetic surfaces) and thus is expected to be environmentally friendly, the control of friction and wear that is of importance for energy conservation and conversion, environmental aspects of lubrication and surface modification techniques, and tribological aspects of green applications such as wind-power turbines or solar panels. This book is the first comprehensive volume on green tribology. The chapters are prepared by leading experts in their fields and cover such topics as biomimetics, environmentally friendly lubrication, tribology of wind turbines and renewable sources of energy, and ecological impact of new technologies of surface treatment.

  4. 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…

  5. Energy Conversion in Protocells with Natural Nanoconductors

    OpenAIRE

    Jian Xu; T. Kyle Vanderlick; David A. LaVan

    2012-01-01

    While much nanotechnology leverages solid-state devices, here we present the analysis of designs for hybrid organic-inorganic biomimetic devices, “protocells,” based on assemblies of natural ion channels and ion pumps, “nanoconductors,” incorporated into synthetic supported lipid bilayer membranes. These protocells mimic the energy conversion scheme of natural cells and are able to directly output electricity. The electrogenic mechanisms have been analyzed and designs were optimized using num...

  6. Biomimetics

    Indian Academy of Sciences (India)

    P Ramachandra Rao

    2003-06-01

    The well-organised multifunctional structures, systems and biogenic materials found in nature have attracted the interest of scientists working in many disciplines. The efforts have resulted in the development of a new and rapidly growing field of scientific effort called biomimetics. In this article we present a few natural materials and systems and explore how ideas from nature are being interpreted and modified to suit efforts aimed at designing better machines and synthesising newer materials.

  7. Conversion of methane to higher hydrocarbons (Biomimetic catalysis of the conversion of methane to methanol). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, B.E.; Taylor, R.T.; Satcher, J.H. [and others

    1993-09-01

    In addition to inorganic catalysts that react with methane, it is well-known that a select group of aerobic soil/water bacteria called methanotrophs can efficiently and selectively utilize methane as the sole source of their energy and carbon for cellular growth. The first reaction in this metabolic pathway is catalyzed by the enzyme methane monooxygenase (MMO) forming methanol. Methanol is a technology important product from this partial oxidation of methane since it can be easily converted to liquid hydrocarbon transportation fuels (gasoline), used directly as a liquid fuel or fuel additive itself, or serve as a feedstock for chemicals production. This naturally occurring biocatalyst (MMO) is accomplishing a technologically important transformation (methane directly to methanol) for which there is currently no analogous chemical (non-biological) process. The authors approach has been to use the biocatalyst, MMO, as the initial focus in the development of discrete chemical catalysts (biomimetic complexes) for methane conversion. The advantage of this approach is that it exploits a biocatalytic system already performing a desired transformation of methane. In addition, this approach generated needed new experimental information on catalyst structure and function in order to develop new catalysts rationally and systematically. The first task is a comparative mechanistic, biochemical, and spectroscopic investigation of MMO enzyme systems. This work was directed at developing a description of the structure and function of the catalytically active sites in sufficient detail to generate a biomimetic material. The second task involves the synthesis, characterization, and chemical reactions of discrete complexes that mimic the enzymatic active site. These complexes were synthesized based on their best current understanding of the MMO active site structure.

  8. 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

  9. 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.

  10. 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

  11. Marine Current Energy Conversion

    OpenAIRE

    Lundin, Staffan

    2016-01-01

    Marine currents, i.e. water currents in oceans and rivers, constitute a large renewable energy resource. This thesis presents research done on the subject of marine current energy conversion in a broad sense. A review of the tidal energy resource in Norway is presented, with the conclusion that tidal currents ought to be an interesting option for Norway in terms of renewable energy. The design of marine current energy conversion devices is studied. It is argued that turbine and generator cann...

  12. Energy Conversion in Protocells with Natural Nanoconductors

    Directory of Open Access Journals (Sweden)

    Jian Xu

    2012-01-01

    Full Text Available While much nanotechnology leverages solid-state devices, here we present the analysis of designs for hybrid organic-inorganic biomimetic devices, “protocells,” based on assemblies of natural ion channels and ion pumps, “nanoconductors,” incorporated into synthetic supported lipid bilayer membranes. These protocells mimic the energy conversion scheme of natural cells and are able to directly output electricity. The electrogenic mechanisms have been analyzed and designs were optimized using numerical models. The parameters that affect the energy conversion are quantified, and limits for device performance have been found using numerical optimization. The electrogenic performance is compared to conventional and emerging technologies and plotted on Ragone charts to allow direct comparisons. The protocell technologies summarized here may be of use for energy conversion where large-scale ion concentration gradients are available (such as the intersection of fresh and salt water sources or small-scale devices where low power density would be acceptable.

  13. 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

  14. 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.

  15. WAVE ENERGY CONVERSION SYSTEMS

    OpenAIRE

    Güney, Mükrimin Şevket

    2015-01-01

    It is a consensus to widespread use of renewable sources for disposal of environmental impact caused by fossil fuel consumption, and moreover to remedy of fossil fuels depletion. Wave power is a renewable kind of energy. Worldwide potential for wave power is enormous. Ocean appears to be an important source of wave energy. Various systems are developed and some new projects are implemented on this subject. Therefore, in this study has been presented the wave energy conversion systems in detai...

  16. 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

  17. Laser energy conversion

    Science.gov (United States)

    Jalufka, N. W.

    1989-01-01

    The conversion of laser energy to other, more useful, forms is an important element of any space power transmission system employing lasers. In general the user, at the receiving sight, will require the energy in a form other than laser radiation. In particular, conversion to rocket power and electricity are considered to be two major areas where one must consider various conversion techniques. Three systems (photovoltaic cells, MHD generators, and gas turbines) have been identified as the laser-to-electricity conversion systems that appear to meet most of the criteria for a space-based system. The laser thruster also shows considerable promise as a space propulsion system. At this time one cannot predict which of the three laser-to-electric converters will be best suited to particular mission needs. All three systems have some particular advantages, as well as disadvantages. It would be prudent to continue research on all three systems, as well as the laser rocket thruster. Research on novel energy conversion systems, such as the optical rectenna and the reverse free-electron laser, should continue due to their potential for high payoff.

  18. Solar energy conversion

    OpenAIRE

    Crabtree, George W.; Lewis, Nathan S.

    2007-01-01

    If solar energy is to become a practical alternative to fossil fuels, we must have efficient ways to convert photons into electricity, fuel, and heat. The need for better conversion technologies is a driving force behind many recent developments in biology, materials, and especially nanoscience.

  19. Microbial Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-10-01

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

  20. 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

  1. 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...

  2. Thermal Energy Conversion Branch

    Science.gov (United States)

    Bielozer, Matthew C.; Schreiber, Jeffrey, G.; Wilson, Scott D.

    2004-01-01

    The Thermal Energy Conversion Branch (5490) leads the way in designing, conducting, and implementing research for the newest thermal systems used in space applications at the NASA Glenn Research Center. Specifically some of the most advanced technologies developed in this branch can be broken down into four main areas: Dynamic Power Systems, Primary Solar Concentrators, Secondary Solar Concentrators, and Thermal Management. Work was performed in the Dynamic Power Systems area, specifically the Stirling Engine subdivision. Today, the main focus of the 5490 branch is free-piston Stirling cycle converters, Brayton cycle nuclear reactors, and heat rejection systems for long duration mission spacecraft. All space exploring devices need electricity to operate. In most space applications, heat energy from radioisotopes is converted to electrical power. The Radioisotope Thermoelectric Generator (RTG) already supplies electricity for missions such as the Cassini Spacecraft. The focus of today's Stirling research at GRC is aimed at creating an engine that can replace the RTG. The primary appeal of the Stirling engine is its high system efficiency. Because it is so efficient, the Stirling engine will significantly reduce the plutonium fuel mission requirements compared to the RTG. Stirling is also being considered for missions such as the lunar/Mars bases and rovers. This project has focused largely on Stirling Engines of all types, particularly the fluidyne liquid piston engine. The fluidyne was developed by Colin D. West. This engine uses the same concepts found in any type of Stirling engine, with the exception of missing mechanical components. All the working components are fluid. One goal was to develop and demonstrate a working Stirling Fluidyne Engine at the 2nd Annual International Energy Conversion Engineering Conference in Providence, Rhode Island.

  3. 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.

  4. Roadmap on optical energy conversion

    Science.gov (United States)

    Boriskina, Svetlana V.; Green, Martin A.; Catchpole, Kylie; Yablonovitch, Eli; Beard, Matthew C.; Okada, Yoshitaka; Lany, Stephan; Gershon, Talia; Zakutayev, Andriy; Tahersima, Mohammad H.; Sorger, Volker J.; Naughton, Michael J.; Kempa, Krzysztof; Dagenais, Mario; Yao, Yuan; Xu, Lu; Sheng, Xing; Bronstein, Noah D.; Rogers, John A.; Alivisatos, A. Paul; Nuzzo, Ralph G.; Gordon, Jeffrey M.; Wu, Di M.; Wisser, Michael D.; Salleo, Alberto; Dionne, Jennifer; Bermel, Peter; Greffet, Jean-Jacques; Celanovic, Ivan; Soljacic, Marin; Manor, Assaf; Rotschild, Carmel; Raman, Aaswath; Zhu, Linxiao; Fan, Shanhui; Chen, Gang

    2016-07-01

    For decades, progress in the field of optical (including solar) energy conversion was dominated by advances in the conventional concentrating optics and materials design. In recent years, however, conceptual and technological breakthroughs in the fields of nanophotonics and plasmonics combined with a better understanding of the thermodynamics of the photon energy-conversion processes reshaped the landscape of energy-conversion schemes and devices. Nanostructured devices and materials that make use of size quantization effects to manipulate photon density of states offer a way to overcome the conventional light absorption limits. Novel optical spectrum splitting and photon-recycling schemes reduce the entropy production in the optical energy-conversion platforms and boost their efficiencies. Optical design concepts are rapidly expanding into the infrared energy band, offering new approaches to harvest waste heat, to reduce the thermal emission losses, and to achieve noncontact radiative cooling of solar cells as well as of optical and electronic circuitries. Light-matter interaction enabled by nanophotonics and plasmonics underlie the performance of the third- and fourth-generation energy-conversion devices, including up- and down-conversion of photon energy, near-field radiative energy transfer, and hot electron generation and harvesting. Finally, the increased market penetration of alternative solar energy-conversion technologies amplifies the role of cost-driven and environmental considerations. This roadmap on optical energy conversion provides a snapshot of the state of the art in optical energy conversion, remaining challenges, and most promising approaches to address these challenges. Leading experts authored 19 focused short sections of the roadmap where they share their vision on a specific aspect of this burgeoning research field. The roadmap opens up with a tutorial section, which introduces major concepts and terminology. It is our hope that the roadmap

  5. Roadmap on optical energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Boriskina, Svetlana V.; Green, Martin A.; Catchpole, Kylie; Yablonovitch, Eli; Beard, Matthew C.; Okada, Yoshitaka; Lany, Stephan; Gershon, Talia; Zakutayev, Andriy; Tahersima, Mohammad H.; Sorger, Volker J.; Naughton, Michael J.; Kempa, Krzysztof; Dagenais, Mario; Yao, Yuan; Xu, Lu; Sheng, Xing; Bronstein, Noah D.; Rogers, John A.; Alivisatos, A. Paul; Nuzzo, Ralph G.; Gordon, Jeffrey M.; Wu, Di M.; Wisser, Michael D.; Salleo, Alberto; Dionne, Jennifer; Bermel, Peter; Greffet, Jean-Jacques; Celanovic, Ivan; Soljacic, Marin; Manor, Assaf; Rotschild, Carmel; Raman, Aaswath; Zhu, Linxiao; Fan, Shanhui; Chen, Gang

    2016-06-24

    For decades, progress in the field of optical (including solar) energy conversion was dominated by advances in the conventional concentrating optics and materials design. In recent years, however, conceptual and technological breakthroughs in the fields of nanophotonics and plasmonics combined with a better understanding of the thermodynamics of the photon energy-conversion processes reshaped the landscape of energy-conversion schemes and devices. Nanostructured devices and materials that make use of size quantization effects to manipulate photon density of states offer a way to overcome the conventional light absorption limits. Novel optical spectrum splitting and photon-recycling schemes reduce the entropy production in the optical energy-conversion platforms and boost their efficiencies. Optical design concepts are rapidly expanding into the infrared energy band, offering new approaches to harvest waste heat, to reduce the thermal emission losses, and to achieve noncontact radiative cooling of solar cells as well as of optical and electronic circuitries. Light-matter interaction enabled by nanophotonics and plasmonics underlie the performance of the third- and fourth-generation energy-conversion devices, including up- and down-conversion of photon energy, near-field radiative energy transfer, and hot electron generation and harvesting. Finally, the increased market penetration of alternative solar energy-conversion technologies amplifies the role of cost-driven and environmental considerations. This roadmap on optical energy conversion provides a snapshot of the state of the art in optical energy conversion, remaining challenges, and most promising approaches to address these challenges. Leading experts authored 19 focused short sections of the roadmap where they share their vision on a specific aspect of this burgeoning research field. The roadmap opens up with a tutorial section, which introduces major concepts and terminology. It is our hope that the roadmap

  6. Compact energy conversion module Project

    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...

  7. Energy conversion and utilization technologies

    International Nuclear Information System (INIS)

    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)

  8. 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.)

  9. 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.

  10. 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.

  11. Materials for energy conversion devices

    CERN Document Server

    Sorrell, C C; Sugihara, S

    2005-01-01

    As the finite capacity and pollution problems of fossil fuels grow more pressing, new sources of more sustainable energy are being developed. Materials for energy conversion devices summarises the key research on new materials which can be used to generate clean and renewable energy or to help manage problems from existing energy sources. The book discusses the range of materials that can be used to harness and convert solar energy in particular, including the properties of oxide materials and their use in producing hydrogen fuel. It covers thermoelectric materials and devices for power genera

  12. Nanoscale Electrothermal Energy Conversion Devices

    OpenAIRE

    Bahk, Je-Hyeong; Ezzahri, Younes; Yazawa, Kazuaki; Vermeersch, Bjorn; Pernot, Gilles; Shakouri, Ali

    2012-01-01

    Energy consumption in our society is increasing rapidly. A significant fraction of the energy is lost in the form of heat. In this talk we introduce thermoelectric devices that allow direct conversion of heat into electricity. Some new physical concepts and nanostructures make it possible to modify the trade-offs between the bulk electrothermal material properties through the changes in the density of states, scattering rates, and interface effects on the electron and phonon transport. The po...

  13. 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.

  14. Pyroelectric energy conversion: optimization principles.

    Science.gov (United States)

    Sebald, Gael; Lefeuvre, Elie; Guyomar, Daniel

    2008-03-01

    In the framework of microgenerators, we present in this paper the key points for energy harvesting from temperature using ferroelectric materials. Thermoelectric devices profit from temperature spatial gradients, whereas ferroelectric materials require temporal fluctuation of temperature, thus leading to different applications targets. Ferroelectric materials may harvest perfectly the available thermal energy whatever the materials properties (limited by Carnot conversion efficiency) whereas thermoelectric material's efficiency is limited by materials properties (ZT figure of merit). However, it is shown that the necessary electric fields for Carnot cycles are far beyond the breakdown limit of bulk ferroelectric materials. Thin films may be an excellent solution for rising up to ultra-high electric fields and outstanding efficiency. Different thermodynamic cycles are presented in the paper: principles, advantages, and drawbacks. Using the Carnot cycle, the harvested energy would be independent of materials properties. However, using more realistic cycles, the energy conversion effectiveness remains dependent on the materials properties as discussed in the paper. A particular coupling factor is defined to quantify and check the effectiveness of pyroelectric energy harvesting. It is defined similarly to an electromechanical coupling factor as k2=p2theta0/(epsilontheta33cE), where p, theta0, epsilontheta33, cE are pyroelectric coefficient, maximum working temperature, dielectric permittivity, and specific heat, respectively. The importance of the electrothermal coupling factor is shown and discussed as an energy harvesting figure of merit. It gives the effectiveness of all techniques of energy harvesting (except the Carnot cycle). It is finally shown that we could reach very high efficiency using 1110.75Pb(Mg1/3Nb2/3)-0.25PbTiO3 single crystals and synchronized switch harvesting on inductor (almost 50% of Carnot efficiency). Finally, practical implementation key

  15. High temperature thermoelectric energy conversion

    International Nuclear Information System (INIS)

    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. Biomass conversion processes for energy and fuels

    Science.gov (United States)

    Sofer, S. S.; Zaborsky, O. R.

    The book treats biomass sources, promising processes for the conversion of biomass into energy and fuels, and the technical and economic considerations in biomass conversion. Sources of biomass examined include crop residues and municipal, animal and industrial wastes, agricultural and forestry residues, aquatic biomass, marine biomass and silvicultural energy farms. Processes for biomass energy and fuel conversion by direct combustion (the Andco-Torrax system), thermochemical conversion (flash pyrolysis, carboxylolysis, pyrolysis, Purox process, gasification and syngas recycling) and biochemical conversion (anaerobic digestion, methanogenesis and ethanol fermentation) are discussed, and mass and energy balances are presented for each system.

  18. Thermal-energy conversion: Under pressure

    Science.gov (United States)

    Phillip, William A.

    2016-07-01

    The conversion of low-grade waste heat into electrical energy is an attractive opportunity to harvest a sustainable energy resource. A thermo-osmotic energy conversion process that uses Earth-abundant materials has now been shown to convert waste heat into electrical energy from sources at temperatures as low as 40 °C.

  19. The chemistry of energy conversion and storage.

    Science.gov (United States)

    Su, Dang Sheng

    2014-05-01

    What's in store: The sustainable development of our society requires the conversion and storage of renewable energy, and these should be scaled up to serve the global primary energy consumption. This special issue on "The Chemistry of Energy Conversion and Storage", assembled by guest editor Dangsheng Su, contains papers dealing with these aspects, and highlights important developments in the chemistry of energy conversion and storage during the last two years.

  20. 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.

  1. Principles of energy conversion, second edition

    International Nuclear Information System (INIS)

    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

  2. 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

  3. Conversion of Chromium(III) Propionate to Chromate/dichromate(VI) by the Advanced Oxidation Process. Pretreatment of a Biomimetic Complex for Metal Analysis

    OpenAIRE

    Lynn Rodman, D.; Carrington, Nathan A.; Xue, Zi-Ling

    2006-01-01

    The use of H2O2 and UV irradiation to remove organic ligands in a chromium(III) complex for the subsequent chromium analysis is reported. The Advanced Oxidation Process (AOP) using a 5.5-W UV lamp, H2O2 and Fe2+/Fe3+ as catalyst (photo Fenton process) was found to give complete and quantitative Cr(III) → Cr(VI) conversion and removal of ligands in chromium(III) propionate [Cr3O(O2CCH2CH3)6(H2O)3]NO3, a biomimetic chromium species, as subsequent chromium analyses by the 1,5-diphenylcarbazide m...

  4. Biomimetics design tool used to develop new components for lower-energy buildings

    OpenAIRE

    Craig, Salmaan

    2008-01-01

    The contributions to knowledge documented in this doctoral thesis are two-fold. The first contribution is in the application of a new biomimetic design tool called BioTRIZ. Its creators claim it can be used to facilitate the transfer of biological principles to solve engineering problems. The core case-study of this thesis documents how this tool was used to frame and systematically explore low-energy solutions to a key technical problem in the underdeveloped field of radiative cooling. Radia...

  5. Energy conversion & storage program. 1994 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, E.J.

    1995-04-01

    The Energy Conversion and Storage Program investigates state-of-the-art electrochemistry, chemistry, and materials science technologies for: (1) development of high-performance rechargeable batteries and fuel cells; (2) development of high-efficiency thermochemical processes for energy conversion; (3) characterization of complex chemical processes and chemical species; (4) study and application of novel materials for energy conversion and transmission. Research projects focus on transport process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis.

  6. 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

  7. Size-Independent Energy Transfer in Biomimetic Nanoring Complexes

    Science.gov (United States)

    2016-01-01

    Supramolecular antenna-ring complexes are of great interest due to their presence in natural light-harvesting complexes. While such systems are known to provide benefits through robust and efficient energy funneling, the relationship between molecular structure, strain (governed by nuclear coordinates and motion), and energy dynamics (arising from electronic behavior) is highly complex. We present a synthetic antenna-nanoring system based on a series of conjugated porphyrin chromophores ideally suited to explore such effects. By systematically varying the size of the acceptor nanoring, we reveal the interplay between antenna-nanoring binding, local strain, and energy dynamics on the picosecond time scale. Binding of the antenna unit creates a local strain in the nanoring, and this strain was measured as a function of the size of the nanoring, by UV–vis-NIR titration, providing information on the conformational flexibility of the system. Strikingly, the energy-transfer rate is independent of nanoring size, indicating the existence of strain-localized acceptor states, spread over about six porphyrin units, arising from the noncovalent antenna-nanoring association. PMID:27176553

  8. Size-Independent Energy Transfer in Biomimetic Nanoring Complexes.

    Science.gov (United States)

    Parkinson, Patrick; Kamonsutthipaijit, Nuntaporn; Anderson, Harry L; Herz, Laura M

    2016-06-28

    Supramolecular antenna-ring complexes are of great interest due to their presence in natural light-harvesting complexes. While such systems are known to provide benefits through robust and efficient energy funneling, the relationship between molecular structure, strain (governed by nuclear coordinates and motion), and energy dynamics (arising from electronic behavior) is highly complex. We present a synthetic antenna-nanoring system based on a series of conjugated porphyrin chromophores ideally suited to explore such effects. By systematically varying the size of the acceptor nanoring, we reveal the interplay between antenna-nanoring binding, local strain, and energy dynamics on the picosecond time scale. Binding of the antenna unit creates a local strain in the nanoring, and this strain was measured as a function of the size of the nanoring, by UV-vis-NIR titration, providing information on the conformational flexibility of the system. Strikingly, the energy-transfer rate is independent of nanoring size, indicating the existence of strain-localized acceptor states, spread over about six porphyrin units, arising from the noncovalent antenna-nanoring association. PMID:27176553

  9. 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...

  10. 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.

  11. Graphene-based materials for energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, Nanda Gopal [Energy Research Institute, Nanyang Technological University (Singapore); Pan, Yongzheng; Li, Lin; Chan, Siew Hwa [School of Mechanical and Aerospace Engineering, Nanyang Technological University (Singapore)

    2012-08-08

    With the depletion of conventional energy sources, the demand for renewable energy and energy-efficient devices continues to grow. As a novel 2D nanomaterial, graphene attracts considerable research interest due to its unique properties and is a promising material for applications in energy conversion and storage devices. Recently, the fabrication of fuel cells and solar cells using graphene for various functional parts has been studied extensively. This research news summarizes and compares the advancements that have been made and are in progress in the utilization of graphene-based materials for energy conversion. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Recycling of wasted energy : thermal to electrical energy conversion

    OpenAIRE

    Lim, Hyuck

    2011-01-01

    Harvesting useful electric energy from ambient thermal gradients and/or temperature fluctuations is immensely important. For many years, a number of direct and indirect thermal-to-electrical energy conversion technologies have been developed. Typically, direct energy conversion is achieved by using thermoelectric generators or thermogalvanic cells; indirect energy conversion is achieved by using Organic Rankine Cycle or Sterling Engines. On the one hand, there is a fundamental technical diffi...

  13. Thermionic energy conversion technology - Present and future

    Science.gov (United States)

    Shimada, K.; Morris, J. F.

    1977-01-01

    Aerospace and terrestrial applications of thermionic direct energy conversion and advances in direct energy conversion (DEC) technology are surveyed. Electrode materials, the cesium plasma drop (the difference between the barrier index and the collector work function), DEC voltage/current characteristics, conversion efficiency, and operating temperatures are discussed. Attention is centered on nuclear reactor system thermionic DEC devices, for in-core or out-of-core operation. Thermionic fuel elements, the radiation shield, power conditions, and a waste heat rejection system are considered among the thermionic DEC system components. Terrestrial applications include topping power systems in fossil fuel and solar power generation.

  14. Electrostatic Conversion for Vibration Energy Harvesting

    OpenAIRE

    Boisseau, S.; Despesse, G.; Seddik, B. Ahmed

    2012-01-01

    Comment: This is an author-created, un-copyedited version of a chapter accepted for publication in Small-Scale Energy Harvesting, Intech. The definitive version is available online at: http://dx.doi.org/10.5772/51360 Please cite as: S. Boisseau, G. Despesse and B. Ahmed Seddik, Electrostatic Conversion for Vibration Energy Harvesting, Small-Scale Energy Harvesting, Intech, 2012

  15. Energy Conversion in Natural and Artificial Photosynthesis

    OpenAIRE

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

    2010-01-01

    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 pho...

  16. Biomimetic thin film synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Graff, G.L.; Campbell, A.A.; Gordon, N.R.

    1995-05-01

    The purpose of this program is to develop a new process for forming thin film coatings and to demonstrate that the biomimetic thin film technology developed at PNL is useful for industrial applications. In the biomimetic process, mineral deposition from aqueous solution is controlled by organic functional groups attached to the underlying substrate surface. The coatings process is simple, benign, inexpensive, energy efficient, and particularly suited for temperature sensitive substrate materials (such as polymers). In addition, biomimetic thin films can be deposited uniformly on complex shaped and porous substrates providing a unique capability over more traditional line-of-sight methods.

  17. Ocean energy conversion - A reality

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.

    stream_size 24 stream_content_type text/plain stream_name Renewable_Energy_Trend_Prospect_2002_84.pdf.txt stream_source_info Renewable_Energy_Trend_Prospect_2002_84.pdf.txt Content-Encoding ISO-8859-1 Content-Type text...

  18. 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...

  19. Power production with direct energy conversion

    International Nuclear Information System (INIS)

    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.)

  20. 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.

  1. 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

  2. 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

  3. Hydraulic wind energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    1981-07-01

    The purpose of this research was to design, build and test a hydraulic wind energy system. This design used a three bladed turbine, which drove a hydraulic pump. The energy is transmitted from the pump through a long hose and into a hydraulic motor, where the energy is used. This wind system was built and tested during the winter of 1980-1981. The power train included a five meter, three bladed wind turbine, a 9.8:1 ratio gearbox, a 1.44 cubic inch displacement pump with a small supercharge gear pump attached. The hydraulic fluid was pumped through a 70', 3/4'' I-D-high pressure flexhose, then through a volume control valve and into a 1.44 cubic inch displacement motor. The fluid was returned through a 70', 1'' I-D-flexhose.

  4. Frontiers of Energy Storage and Conversion

    Directory of Open Access Journals (Sweden)

    Jiajun Chen

    2014-09-01

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

  5. 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. PMID:26092694

  6. 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.

  7. 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.

  8. Energy from Biomass for Conversion of Biomass

    Science.gov (United States)

    Abolins, J.; Gravitis, J.

    2009-01-01

    Along with estimates of minimum energy required by steam explosion pre-treatment of biomass some general problems concerning biomass conversion into chemicals, materials, and fuels are discussed. The energy necessary for processing biomass by steam explosion auto-hydrolysis is compared with the heat content of wood and calculated in terms of the amount of saturated steam consumed per unit mass of the dry content of wood biomass. The fraction of processed biomass available for conversion after steam explosion pre-treatment is presented as function of the amount of steam consumed per unit mass of the dry content of wood. The estimates based on a simple model of energy flows show the energy required by steam explosion pre-treatment of biomass being within 10% of the heat content of biomass - a realistic amount demonstrating that energy for the process can be supplied from a reasonable proportion of biomass used as the source of energy for steam explosion pre-treatment.

  9. Biomimetic staggered composites with highly enhanced energy dissipation: Modeling, 3D printing, and testing

    Science.gov (United States)

    Zhang, Pu; Heyne, Mary A.; To, Albert C.

    2015-10-01

    We investigate the damping enhancement in a class of biomimetic staggered composites via a combination of design, modeling, and experiment. In total, three kinds of staggered composites are designed by mimicking the structure of bone and nacre. These composite designs are realized by 3D printing a rigid plastic and a viscous elastomer simultaneously. Greatly-enhanced energy dissipation in the designed composites is observed from both the experimental results and theoretical prediction. The designed polymer composites have loss modulus up to ~500 MPa, higher than most of the existing polymers. In addition, their specific loss modulus (up to 0.43 km2/s2) is among the highest of damping materials. The damping enhancement is attributed to the large shear deformation of the viscous soft matrix and the large strengthening effect from the rigid inclusion phase.

  10. Thermo electronic laser energy conversion

    Science.gov (United States)

    Hansen, L. K.; Rasor, N. S.

    1976-01-01

    The thermo electronic laser energy converter (TELEC) is described and compared to the Waymouth converter and the conventional thermionic converter. The electrical output characteristics and efficiency of TELEC operation are calculated for a variety of design variables. Calculations and results are briefly outlined. It is shown that the TELEC concept can potentially convert 25 to 50 percent of incident laser radiation into electric power at high power densities and high waste heat rejection temperatures.

  11. Energy Conversion: Nano Solar Cell

    Science.gov (United States)

    Yahaya, Muhammad; Yap, Chi Chin; Mat Salleh, Muhamad

    2009-09-01

    Problems of fossil-fuel-induced climate change have sparked a demand for sustainable energy supply for all sectors of economy. Most laboratories continue to search for new materials and new technique to generate clean energy at affordable cost. Nanotechnology can play a major role in solving the energy problem. The prospect for solar energy using Si-based technology is not encouraging. Si photovoltaics can produce electricity at 20-30 c//kWhr with about 25% efficiency. Nanoparticles have a strong capacity to absorb light and generate more electrons for current as discovered in the recent work of organic and dye-sensitized cell. Using cheap preparation technique such as screen-printing and self-assembly growth, organic cells shows a strong potential for commercialization. Thin Films research group at National University Malaysia has been actively involved in these areas, and in this seminar, we will present a review works on nanomaterials for solar cells and particularly on hybrid organic solar cell based on ZnO nanorod arrays. The organic layer consisting of poly[2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEHPPV) and [6, 6]-phenyl C61-butyric acid 3-ethylthiophene ester (PCBE) was spin-coated on ZnO nanorod arrays. ZnO nanorod arrays were grown on FTO glass substrates which were pre-coated with ZnO nanoparticles using a low temperature chemical solution method. A gold electrode was used as the top contact. The device gave a short circuit current density of 2.49×10-4 mA/cm2 and an open circuit voltage of 0.45 V under illumination of a projector halogen light at 100 mW/cm2.

  12. Chalcogenide Materials for Solar Energy Conversion

    Directory of Open Access Journals (Sweden)

    Péter Turmezei

    2004-11-01

    Full Text Available The problem of electrical energy storage can possibly be solved with the help of electrochemical solar cells, which are suitable to generate either electrical energy or hydrogen gas under special conditions. The greatest problem of the electrochemical solar cell technology is to find novel materials which have appropriate properties for electrochemical energy conversion. In this work Cd4GeSe6, a novel material for electrochemical solar cells, will be presented.

  13. 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.

  14. Direct conversion of muon catalyzed fusion energy

    International Nuclear Information System (INIS)

    In this paper a method of direct conversion of muon catalyzed fusion (MCF) energy is proposed in order to reduce the cost of muon production. This MCF concept is based on a pellet composed of many thin solid deuterium-tritium (DT) rods encircled by a metallic circuit immersed in a magnetic field. The direct energy conversion is the result of the heating of the pellet by beam injection and fusion alphas. The expanding DT rods causes the change of magnetic flux linked by the circuit. Our calculation shows that the direct conversion method reduces the cost of one muon by a factor of approximately 2.5 over the previous methods. The present method is compatible with a reactor using the pellet concept, where the muon sticking is reduced by the ion cyclotron resonance heating and the confinement of the exploding pellet is handled by magnetic fields and the coronal plasma. 17 refs., 6 figs

  15. Mixed Magnetism for Refrigeration and Energy Conversion

    NARCIS (Netherlands)

    Dung, Nguyen H.; Ou, Zhi Qiang; Caron, Luana; Zhang, Lian; Cam Thanh, Dinh T.; Wijs, Gilles A. de; Groot, Rob A. de; Buschow, K.H. Jürgen; Brück, Ekkes

    2011-01-01

    The efficient coupling between lattice degrees of freedom and spin degrees of freedom in magnetic materials can be used for refrigeration and energy conversion. This coupling is enhanced in materials exhibiting the giant magnetocaloric effect. First principle electronic structure calculations on hex

  16. 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.

  17. Biological and Biomimetic Low-Temperature Routes to Materials for Energy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Morse, Daniel E. [Univ. of California, Santa Barbara, CA (United States)

    2016-08-29

    New materials are needed to significantly improve the efficiencies of energy harnessing, transduction and storage. To help address this need, we developed a new, bio-inspired catalytic synthesis method that is low-cost, operating at low temperature and without the use of polluting chemicals. In addition to direct applications for improvement of batteries and fuel cells, the broader impact of this research includes a deeper fundamental understanding of the factors governing kinetically controlled synthesis and its control of the emergent nanostructure and performance of a wide range of nanomaterials for energy applications. We first combined molecular genetics and materials science to elucidate the molecular mechanism by which a novel family of proteins that we discovered. We showed that these “silicatein” proteins and their biomimetic analogs can be used to simultaneously catalyze and structurally direct the synthesis, at low temperature, of silica, silicone polymers, and a wide variety of crystalline metal oxide semiconductors – materials with which biology had never built structures before. We successfully translated the biomolecular mechanism of synthesis that we discovered to a robust new methodology, without the use of organic molecules, capable of producing nanostructurally controlled metal oxide and related semiconductors for improved efficiency of energy generation, transduction and storage. The method we developed uses vapor diffusion of a catalyst through a gas-liquid interface to provide vectorially controlled catalysis, at low temperature, of synthesis from molecular precursors that require hydrolysis. The result is a novel low-temperature and environmentally benign method for the nanofabrication of a wide range of metal oxide, metal hydroxide and metal phosphate semiconductors, in unique and potentially useful crystal morphologies - some of which could never have been made before - with significantly enhanced electronic performance. The novelty

  18. Novel Nuclear Powered Photocatalytic Energy Conversion

    International Nuclear Information System (INIS)

    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

  19. 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

  20. Energy Conversion at Micro and Nanoscale

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

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

  2. 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.

  3. Low Speed Energy Conversion from Marine Currents

    OpenAIRE

    Thomas, Karin

    2007-01-01

    The focus of this thesis is research on the performance of very low speed direct drive permanent magnet generators for energy conversion from marine and tidal currents. Various aspects involved in the design of these generators and their electromagnetic modelling using the finite element simulations are presented. For a detailed study, a 5 kW prototype generator has been designed and constructed based on finite element based simulations. Several experiments were conducted on the prototype gen...

  4. Thermomechanical Energy Conversion Using Ferroelectric Materials

    OpenAIRE

    McKinley, Ian Meeker

    2013-01-01

    This study is concerned with the direct conversion of thermal and mechanical energy into electricity using ferroelectric materials. These materials possess a spontaneous polarization and can undergo solid-state phase transitions as a result of a change in applied electric field. All ferroelectric materials are pyroelectric, i.e., phase transitions can also be induced by a change in temperature. The Olsen cycle takes advantage of the thermally-induced phase transitions to directly convert ther...

  5. Air Turbines for Wave Energy Conversion

    OpenAIRE

    Manabu Takao; Toshiaki Setoguchi

    2012-01-01

    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 ...

  6. Mixed Magnetism for Refrigeration and Energy Conversion

    OpenAIRE

    Dung, Nguyen H; Ou, Zhi Qiang; Caron, Luana; Zhang, Lian; Cam Thanh, Dinh T.; de Wijs, Gilles A.; Groot, Rob A. de; Buschow, K.H. Jürgen; Brück, Ekkes

    2011-01-01

    The efficient coupling between lattice degrees of freedom and spin degrees of freedom in magnetic materials can be used for refrigeration and energy conversion. This coupling is enhanced in materials exhibiting the giant magnetocaloric effect. First principle electronic structure calculations on hexagonal MnFe(P, Si) reveal a new form of magnetism: the coexistence of strong and weak magnetism in alternate atomic layers. The weak magnetism of Fe layers (disappearance of local magnetic moments ...

  7. 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.

  8. Ocean energy conversion systems annual research report

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    Alternative power cycle concepts to the closed-cycle Rankine are evaluated and those that show potential for delivering power in a cost-effective and environmentally acceptable fashion are explored. Concepts are classified according to the ocean energy resource: thermal, waves, currents, and salinity gradient. Research projects have been funded and reported in each of these areas. The lift of seawater entrained in a vertical steam flow can provide potential energy for a conventional hydraulic turbine conversion system. Quantification of the process and assessment of potential costs must be completed to support concept evaluation. Exploratory development is being completed in thermoelectricity and 2-phase nozzles for other thermal concepts. Wave energy concepts are being evaluated by analysis and model testing with present emphasis on pneumatic turbines and wave focussing. Likewise, several conversion approaches to ocean current energy are being evaluated. The use of salinity resources requires further research in membranes or the development of membraneless processes. Using the thermal resource in a Claude cycle process as a power converter is promising, and a program of R and D and subsystem development has been initiated to provide confirmation of the preliminary conclusion.

  9. Oriented nanostructures for energy conversion and storage.

    Science.gov (United States)

    Liu, Jun; Cao, Guozhong; Yang, Zhenguo; Wang, Donghai; Dubois, Dan; Zhou, Xiaodong; Graff, Gordon L; Pederson, Larry R; Zhang, Ji-Guang

    2008-01-01

    Recently, the role of nanostructured materials in addressing the challenges in energy and natural resources has attracted wide attention. In particular, oriented nanostructures demonstrate promising properties for energy harvesting, conversion, and storage. In this Review, we highlight the synthesis and application of oriented nanostructures in a few key areas of energy technologies, namely photovoltaics, batteries, supercapacitors, and thermoelectrics. Although the applications differ from field to field, a common fundamental challenge is to improve the generation and transport of electrons and ions. We highlight the role of high surface area to maximize the surface activity and discuss the importance of optimum dimension and architecture, controlled pore channels, and alignment of the nanocrystalline phase to optimize the transport of electrons and ions. Finally, we discuss the challenges in attaining integrated architectures to achieve the desired performance. Brief background information is provided for the relevant technologies, but the emphasis is focused mainly on the nanoscale effects of mostly inorganic-based materials and devices.

  10. Wind Energy Conversion Based on Matrix Converter

    Directory of Open Access Journals (Sweden)

    Mutharasan Anburaj

    2014-07-01

    Full Text Available In recent years renewable sources such as solar, wave and wind are used for the generation of electricity. Wind is one of the major renewable sources. The amount of energy from a Wind Energy Conversion System (WECS depends not only on the wind at the site, but also on the control strategy used for the WECS. In assistance to get the appropriate wind energy from the conversion system, wind turbine generator will be run in variable speed mode. The variable speed capability is achieved through the use of an advanced power electronic converter. Fixed speed wind turbines and induction generators are often used in wind farms. But the limitations of such generators are low efficiency and poor power quality which necessitates the variable speed wind turbine generators such as Doubly Fed Induction Generator (DFIG and Permanent Magnet Synchronous Generator (PMSG. A high-performance configuration can be obtained by using Scherbius drive composed of a DFIG and a converter in combination AC-DC-AC connect between stator & rotor points for providing the required variable speed operation

  11. 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.

  12. Recycling of Wasted Energy: Thermal to Electrical Energy Conversion

    Science.gov (United States)

    Lim, Hyuck

    Harvesting useful electric energy from ambient thermal gradients and/or temperature fluctuations is immensely important. For many years, a number of direct and indirect thermal-to-electrical energy conversion technologies have been developed. Typically, direct energy conversion is achieved by using thermoelectric generators or thermogalvanic cells; indirect energy conversion is achieved by using Organic Rankine Cycle or Sterling Engines. On the one hand, there is a fundamental technical difficulty, thermal shorting, that limits the energy conversion efficiency of direct thermoelectric energy conversion methods. While extensive study has been conducted in this area, currently the portion of thermal energy that can be converted to electricity is still small. On the other hand, the indirect energy conversion systems tend to be complicated and expensive. Thus, existing energy harvesting technologies are less economically competitive compared with the grid power. To develop advanced energy harvesting systems, a novel concept using nanoporous materials is investigated. Nanoporous materials have been widely used as advanced absorbents. Because of their ultra-large surface areas (100--2000 m2/g), they can adsorb a large amount of ions when they are immersed in electrolyte solutions. The ion adsorption capacity is thermally dependent. If two nanoporous electrodes are placed at different temperatures, they adsorb different amounts of ions, generating a net output voltage. The thermally driven ion motion causes a transient current, which can be reactivated through temperature fluctuation or internal grounding. The two electrodes are isolated; that is, the direct heat loss between them is minimized. Our experimental data have shown encouraging results: the output voltage and the energy conversion efficiency are higher than that of conventional thermoelectric materials by orders of magnitude. Our study will not only lead to the development of high-performance thermal energy

  13. Solar thermal energy conversion to electrical power

    International Nuclear Information System (INIS)

    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

  14. Black metallurgical silicon for solar energy conversion

    International Nuclear Information System (INIS)

    Metal impurities are known to create deep traps in the silicon (Si) bandgap, significantly reducing the minority carrier lifetime and consequently deteriorating the efficiency of a Si-based solar conversion system. Traditional purification methods via ‘Siemens’ and metallurgical routes involve complex and energy-intensive processes. Therefore, it is highly desirable to develop novel Si treatment technologies. With the radical evolution of nanotechnology in the past decades, new nano-approaches are offering opportunities to diminish the detrimental impacts of metal impurities or upgrade low quality Si in a cost-effective and energy-saving way. Here we review various recently developed dry and wet chemical etching methods including reactive ion etching, electrochemical etching, stain etching and metal assisted chemical etching. The current progress and the application prospects of those methods in nanostructure creation and Si upgrading are given and discussed in detail. (paper)

  15. 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.

  16. Biomass energy conversion: conventional and advanced technologies

    International Nuclear Information System (INIS)

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

  17. Some Sustainability Aspects of Energy Conversion in Urban Electric Trains

    OpenAIRE

    Doru A. Nicola; Marc A. Rosen; Cornelia A. Bulucea; Constantin Brandusa

    2010-01-01

    The paper illustrates some aspects of energy conversion processes during underground electric train operation. Energy conversion processes are explained using exergy, in order to support transport system sustainability. Loss of exergy reflects a loss of potential of energy to do work. Following the notion that life in Nature demonstrates sustainable energy conversion, we approach the sustainability of urban transportation systems according to the model of an ecosystem. The presentation steps ...

  18. Advanced Catalysis and Nanostructure Design for Solar Energy Conversion

    OpenAIRE

    Shaohua Shen; Ke Sun; Haimin Zhang; Yongqi Liang

    2014-01-01

    Solar energy conversion has been intensively studied in past decades and has been shown to be greatly effective for solving the serious environmental pollution and energy shortage problems. Photoelectrocatalysis and photovoltaics have been considered as the two main approaches for solar energy conversion and utilization, which are generally involved with nanostructured materials and/or catalytic processes, greatly affecting the efficiencies for solar energy conversion. Then, it is necessary t...

  19. 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.

  20. 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.

  1. Power conversion from environmentally scavenged energy sources.

    Energy Technology Data Exchange (ETDEWEB)

    Druxman, Lee Daniel

    2007-09-01

    As the power requirements for modern electronics continue to decrease, many devices which were once dependent on wired power are now being implemented as portable devices operating from self-contained power sources. The most prominent source of portable power is the electrochemical battery, which converts chemical energy into electricity. However, long lasting batteries require large amounts of space for chemical storage, and inevitably require replacement when the chemical reaction no longer takes place. There are many transducers and scavenging energy sources (SES) that are able to exploit their environment to generate low levels of electrical power over a long-term time period, including photovoltaic cells, thermoelectric generators, thermionic generators, and kinetic/piezoelectric power generators. This generated power is sustainable as long as specific environmental conditions exist and also does not require the large volume of a long lifetime battery. In addition to the required voltage generation, stable power conversion requires excess energy to be efficiently stored in an ultracapacitor or similar device and monitoring control algorithms to be implemented, while computer modeling and simulation can be used to complement experimental testing. However, building an efficient and stable power source scavenged from a varying input source is challenging.

  2. Direct energy conversion using liquid metals

    Directory of Open Access Journals (Sweden)

    Onea Alexandru

    2014-01-01

    Full Text Available Liquid metals have excellent properties to be used as heat transport fluids due to their high thermal conductivity and their wide applicable temperature range. The latter issue can be used to go beyond limitations of existing thermal solar energy systems. Furthermore, the direct energy converter Alkali Metal Thermo Electric Converter (AMTEC can be used to make intangible areas of energy conversion suitable for a wide range of applications. One objective is to investigate AMTEC as a complementary cycle for the next generation of concentrating solar power (CSP systems. The experimental research taking place in the Karlsruhe Institute of Technology (KIT is focused on the construction of a flexible AMTEC test facility, development, test and improvement of liquid-anode and vapor-anode AMTEC devices as well as the coupling of the AMTEC cold side to the heat storage tank proposed for the CSP system. Within this project, the investigations foreseen will focus on the analyses of BASE-metal interface, electrode materials and deposition techniques, corrosion and erosion of materials brought in contact with high temperature sodium. This prototype demonstrator is planned to be integrated in the KArlsruhe SOdium LAboratory (KASOLA, a flexible closed mid-size sodium loop, completely in-house designed, presently under construction at the Institute for Neutron Physics and Reactor Technology (INR within KIT.

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

    OpenAIRE

    Yongfeng Luo; Xi Li; Jianxiong Zhang; Chunrong Liao; Xianjun Li

    2014-01-01

    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 lo...

  4. Science of Nanofluidics and Energy Conversion

    Science.gov (United States)

    Xu, Baoxing

    The emerging subject of nanofluidics, where solids and fluids interact closely at the nanoscale, has exhibited radically different from their macroscopic counterparts (and sometimes counterintuitive), and yet relatively less explored. On the other hand, the resulting unique properties may contribute to a number of innovative functions with fascinating applications. Among various exciting potential applications, an important and ever expanding one is to provide alternative solutions to energy conversion with high efficiency, including energy absorption, actuation and harvesting. In this dissertation, we first report a novel protection mechanism of energy capture through which an intensive impact or blast energy can be effectively mitigated based on a nonwetting liquid-nanoporous material system. The captured energy is stored in nanopores in the form of potential energy of intercalated water molecules for a while, and not necessarily converted to other forms of energy (e.g. heat). At unloading stage, the captured energy will be released gradually due to the hydrophobic inner surfaces of nanopores through the diffusion of water molecules out of nanopores, thus making this system reusable. Several key controlling factors including impacting velocity, nanopore size, nanopore structure, and liquid phase have been investigated on the capacity of energy capture. The molecular mechanism is elucidated through the study of water molecular distributions inside nanpores. These molecular dynamic (MD) findings are quantitatively verified by a parallel blast experiment on a zeolite/water system. During the transport of confined liquid molecules, the friction resistance exerted by solid atoms of nanopores to liquid molecules will dissipate part of energy, and is highly dependent of temperature of liquid molecules and wall morphology of nanopores. Using MD simulations, the effects of temperature and wall roughness on the transport resistance of water molecules inside nanopores are

  5. 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.

  6. 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.…

  7. 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...

  8. Research on Energy Conversion System of Floating Wave Energy Converter

    Institute of Scientific and Technical Information of China (English)

    张亚群; 盛松伟; 游亚戈; 吴必军; 刘洋

    2014-01-01

    A wave power device includes an energy harvesting system and a power take-off system. The power take-off system of a floating wave energy device is the key that converts wave energy into other forms. A set of hydraulic power take-off system, which suits for the floating wave energy devices, includes hydraulic system and power generation system. The hydraulic control system uses a special“self-hydraulic control system”to control hydraulic system to release or save energy under the maximum and the minimum pressures. The maximum pressure is enhanced to 23 MPa, the minimum to 9 MPa. Quite a few experiments show that the recent hydraulic system is evidently improved in efficiency and reliability than our previous one, that is expected to be great significant in the research and development of our prototype about wave energy conversion.

  9. Research on energy conversion system of floating wave energy converter

    Science.gov (United States)

    Zhang, Ya-qun; Sheng, Song-wei; You, Ya-ge; Wu, Bi-jun; Liu, Yang

    2014-03-01

    A wave power device includes an energy harvesting system and a power take-off system. The power take-off system of a floating wave energy device is the key that converts wave energy into other forms. A set of hydraulic power take-off system, which suits for the floating wave energy devices, includes hydraulic system and power generation system. The hydraulic control system uses a special "self-hydraulic control system" to control hydraulic system to release or save energy under the maximum and the minimum pressures. The maximum pressure is enhanced to 23 MPa, the minimum to 9 MPa. Quite a few experiments show that the recent hydraulic system is evidently improved in efficiency and reliability than our previous one, that is expected to be great significant in the research and development of our prototype about wave energy conversion.

  10. 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

  11. 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

  12. Conversion of poultry wastes into energy feedstocks.

    Science.gov (United States)

    Kantarli, Ismail Cem; Kabadayi, Arzu; Ucar, Suat; Yanik, Jale

    2016-10-01

    In this study, conversion of wastes from poultry farming and industry into biochar and bio-oil via thermochemical processes was investigated. Fuel characteristics and chemical structure of biochars and bio-oils have been investigated using standard fuel analysis and spectroscopic methods. Biochars were produced from poultry litter through both hydrothermal carbonization (sub-critical water, 175-250°C) and pyrolysis over a temperature range between 250 and 500°C. In comparison to hydrothermal carbonization, pyrolysis at lower temperatures produced biochar with greater energy yield due to the higher mass yield. Biochars obtained by both processes were comparable to coal. Hydrothermal liquefaction of poultry meal at different temperatures (200-325°C) was conducted and compared to optimize its process conditions. Higher temperatures favored the formation of bio-crude oil, with a maximum yield of 35wt.% at 300°C. The higher heating values of bio-oils showed that bio-oil could be a potential source of synthetic fuels. However, elemental analysis demonstrated the high nitrogen content of bio-oils. Therefore, bio-oils obtained from hydrothermal liquefaction of poultry meal should be upgraded for utilization as a transport and heating fuel. PMID:27440220

  13. Direct Energy Conversion for Fast Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.; Cooper, J.; Vogt, D.; Chapline, G.; Turchi, P.; Barbee Jr., T.; Farmer, J.

    2000-07-01

    Thermoelectric generators (TEG) are a well-established technology for compact low power output long-life applications. Solid state TEGs are the technology of choice for many space missions and have also been used in remote earth-based applications. Since TEGs have no moving parts and can be hermetically sealed, there is the potential for nuclear reactor power systems using TEGs to be safe, reliable and resistant to proliferation. Such power units would be constructed in a manner that would provide decades of maintenance-free operation, thereby minimizing the possibility of compromising the system during routine maintenance operations. It should be possible to construct an efficient direct energy conversion cascade from an appropriate combination of solid-state thermoelectric generators, with each stage in the cascade optimized for a particular range of temperature. Performance of cascaded thermoelectric devices could be further enhanced by exploitation of compositionally graded p-n couples, as well as radial elements to maximize utilization of the heat flux. The Jet Propulsion Laboratory in Pasadena has recently reported segmented unicouples that operate between 300 and 975 K and have conversion efficiencies of 15 percent [Caillat, 2000]. TEGs are used in nuclear-fueled power sources for space exploration, in power sources for the military, and in electrical generators on diesel engines. Second, there is a wide variety of TE materials applicable to a broad range of temperatures. New materials may lead to new TEG designs with improved thermoelectric properties (i.e. ZT approaching 3) and significantly higher efficiencies than in designs using currently available materials. Computational materials science (CMS) has made sufficient progress and there is promise for using these techniques to reduce the time and cost requirements to develop such new TE material combinations. Recent advances in CMS, coupled with increased computational power afforded by the Accelerated

  14. Conversion potential energy and its application to thermodynamic optimization

    Institute of Scientific and Technical Information of China (English)

    WU Jing; GUO ZengYuan

    2012-01-01

    In general,heat transfers can be classified into two categories according to the purposes of object heating or cooling and the heat to work conversion.Recently,a new physical quantity,entransy (or potential energy),was proposed to describe the ability of heat transfer with the former purpose.This paper addresses the concept of potential energy in terms of the heat transfer processes for the latter purpose,named the conversion potential energy.The physical meaning of this newly introduced concept is the potential energy for the heat to work conversion stored in the equivalent mass of heat (thermomass) derived on the basis of the Einstein's special theory of relativity.The dissipation of conversion potential energy occurs during the real irreversible heat to work conversion processes as a measure of the conversion irreversibility.Finally,a heat to work conversion problem of a heat exchanger group is provided to show that the minimum conversion potential energy dissipation rate can be used as an optimization criterion for the heat transfer performance with the purpose of the heat to work conversion.

  15. 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

  16. 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.

  17. CONVERSION EFFICIENCY IMPROVEMENT FOR ENERGY CONSERVATION USING MATRIX CONVERTER

    OpenAIRE

    G.N. SURYA; SUBROTO DUTT

    2012-01-01

    Efficient conversion of electrical energy from one form to another has always been a fascinating domain for researchers. Right from the era of mercury arc rectifiers to present AC-DC-AC two stage converters and cycloconverters, efforts are consistently being laid to minimize the losses involved in conversion process. In the present study the AC-AC conversion topology known as Matrix Converter (MC), is modeled using MATLAB. Venturini’s simplified algorithm is used to determine the switch modul...

  18. Fabrication of biomolecule copolymer hybrid nanovesicles as energy conversion systems

    Science.gov (United States)

    Ho, Dean; Chu, Benjamin; Lee, Hyeseung; Brooks, Evan K.; Kuo, Karen; Montemagno, Carlo D.

    2005-12-01

    This work demonstrates the integration of the energy-transducing proteins bacteriorhodopsin (BR) from Halobacterium halobium and cytochrome c oxidase (COX) from Rhodobacter sphaeroides into block copolymeric vesicles towards the demonstration of coupled protein functionality. An ABA triblock copolymer-based biomimetic membrane possessing UV-curable acrylate endgroups was synthesized to serve as a robust matrix for protein reconstitution. BR-functionalized polymers were shown to generate light-driven transmembrane pH gradients while pH gradient-induced electron release was observed from COX-functionalized polymers. Cooperative behaviour observed from composite membrane functionalized by both proteins revealed the generation of microamp-range currents with no applied voltage. As such, it has been shown that the fruition of technologies based upon bio-functionalizing abiotic materials may contribute to the realization of high power density devices inspired by nature.

  19. 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.

  20. Soft materials for linear electromechanical energy conversion

    OpenAIRE

    Jakli, Antal; Eber, Nandor

    2014-01-01

    We briefly review the literature of linear electromechanical effects of soft materials, especially in synthetic and biological polymers and liquid crystals (LCs). First we describe results on direct and converse piezoelectricity, and then we discuss a linear coupling between bending and electric polarization, which maybe called bending piezoelectricity, or flexoelectricity.

  1. 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.

  2. Nanowires for thermal energy conversion and management

    Science.gov (United States)

    Chen, Renkun

    This dissertation presents the application of nanowires in two aspects of thermal energy conversion and management: (i) silicon (Si) nanowires as efficient and scalable thermoelectric materials due to the reduced thermal conductivity (k), and (ii) Si and copper (Cu) nanowire arrays for enhanced phase change heat transfer including boiling and evaporation and their applications in thermal management of microelectronics. In the first half of the thesis (chapter 2 and 3), we describe thermal and thermoelectric measurements of individual Si nanowires for studying phonon transport properties and their potential application in thermoelectrics. A theoretical model based on coherent phonon scattering was developed to explain the experiemental data, which suggests that phonon-boundary scattering is highly frequency dependent. For low frequency (long wavelength) phonons, the transport is nearly ballistic, whereas high frequency or short wavelength phonons scatter diffusively at nanowire boundary. The competition between the two phonon transmission regimes results in the unusual linear behavior of the thermal conductance of thin VLS Si nanowires at low temperature. Next, the thermal conductivity of EE Si nanowires, which have much rougher surface compared to VLS nanowires, was measured and found to be five-eight times lower than that of VLS counterparts with similar diameters. The substantial reduction in k is presumably due to the higher surface roughness, since both types of nanowires have single crystalline cores. In particular, for ˜ 50 nm EE Si nanowires etched from 0.1 O-cm B-doped p-Si (˜2 x 1017 cm-3 dopant concentration), the k is around 1.6 Wm-1K-1 and the kL is ˜1.2 Wm-1 K-1 at room temperature, approaching that of amorphous Si. The single nanowire measurements show the great promise of using Si nanowire arrays as high-performance, scalable thermoelectric materials. As the second focus of the thesis (chapter 4 and 5), nanowire arrays were used for enhanced phase

  3. 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.

  4. 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.

  5. 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.

  6. Guest Editorial Advanced Distributed Control of Energy Conversion Devices and Systems

    DEFF Research Database (Denmark)

    Davoudi, Ali; Guerrero, Josep M.; Lewis, Frank;

    2014-01-01

    The papers in this special issue on advanced distributed control of energy conversion devices and systems are loosely grouped into three categories: 1) ac energy conversion systems; 2) dc energy conversion systems; and 3) optimization and standards.......The papers in this special issue on advanced distributed control of energy conversion devices and systems are loosely grouped into three categories: 1) ac energy conversion systems; 2) dc energy conversion systems; and 3) optimization and standards....

  7. Self-powered energy fiber: energy conversion in the sheath and storage in the core.

    Science.gov (United States)

    Yang, Zhibin; Deng, Jue; Sun, Hao; Ren, Jing; Pan, Shaowu; Peng, Huisheng

    2014-11-01

    A high-performance, self-powered, elastic energy fiber is developed that consists of an energy conversion sheath and an energy storage core. The coaxial structure and the aligned nanostructures at the electrode interface enable a high total energy-conversion and energy-storage performance that is maintained under bending and after stretching.

  8. Energy Conversion and Storage Program: 1992 Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, E.J.

    1993-06-01

    This report is the 1992 annual progress report for the Energy Conversion and Storage Program, a part of the Energy and Environment Division of the Lawrence Berkeley Laboratory. Work described falls into three broad areas: electrochemistry; chemical applications; and materials applications. The Energy Conversion and Storage Program applies principles of chemistry and materials science to solve problems in several areas: (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 chemical species, and (5) study and 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. 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 product and waste streams from synfuel plants, coal gasifiers, and biomass conversion processes. Materials applications research includes evaluation of the properties of advanced materials, as well as development of novel preparation techniques. For example, techniques such as sputtering, laser ablation, and poised laser deposition are being used to produce high-temperature superconducting films.

  9. 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....... Finally, main issues concerning fuel cell (FC) systems as generators based on hydrogen as a low environmental impact energy vector are presented....

  10. 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

  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. Giant osmotic energy conversion measured in a single transmembrane boron nitride nanotube.

    Science.gov (United States)

    Siria, Alessandro; Poncharal, Philippe; Biance, Anne-Laure; Fulcrand, Rémy; Blase, Xavier; Purcell, Stephen T; Bocquet, Lydéric

    2013-02-28

    New models of fluid transport are expected to emerge from the confinement of liquids at the nanoscale, with potential applications in ultrafiltration, desalination and energy conversion. Nevertheless, advancing our fundamental understanding of fluid transport on the smallest scales requires mass and ion dynamics to be ultimately characterized across an individual channel to avoid averaging over many pores. A major challenge for nanofluidics thus lies in building distinct and well-controlled nanochannels, amenable to the systematic exploration of their properties. Here we describe the fabrication and use of a hierarchical nanofluidic device made of a boron nitride nanotube that pierces an ultrathin membrane and connects two fluid reservoirs. Such a transmembrane geometry allows the detailed study of fluidic transport through a single nanotube under diverse forces, including electric fields, pressure drops and chemical gradients. Using this device, we discover very large, osmotically induced electric currents generated by salinity gradients, exceeding by two orders of magnitude their pressure-driven counterpart. We show that this result originates in the anomalously high surface charge carried by the nanotube's internal surface in water at large pH, which we independently quantify in conductance measurements. The nano-assembly route using nanostructures as building blocks opens the way to studying fluid, ionic and molecule transport on the nanoscale, and may lead to biomimetic functionalities. Our results furthermore suggest that boron nitride nanotubes could be used as membranes for osmotic power harvesting under salinity gradients.

  13. 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.

  14. 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

  15. 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

  16. Hydro-Kinetic Energy Conversion : Resource and Technology

    OpenAIRE

    Grabbe, Mårten

    2013-01-01

    The kinetic energy present in tidal currents and other water courses has long been appreciated as a vast resource of renewable energy. The work presented in this doctoral thesis is devoted to both the characteristics of the hydro-kinetic resource and the technology for energy conversion. An assessment of the tidal energy resource in Norwegian waters has been carried out based on available data in pilot books. More than 100 sites have been identified as interesting with a total estimated theor...

  17. 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......This paper intends contributing to an economically and environmentally sustainable development of coastal infrastructures by investigating the possibility of combining together breakwaters and Wave Energy Converters (WEC). The latter change the wave energy to electricity, which may serve both...

  18. Rosier future for solar energy conversion

    Institute of Scientific and Technical Information of China (English)

    SONG Jianlan

    2008-01-01

    @@ Recent progress in dye-sensitized solar cells (DSCs) research and development,which use innovative light-harvesting dye (the "sensitizer") to improve the optical absorption coefficient of the stained nanostructured electrodes,might color our seemingly dimming future energy security with a tint of rose,despite the looming depletion of fossil fuels.Costing only 10~20% as its silicon counterparts,the new devices might make it affordable for much more people to utilize solar energy,a handy renewable energy source.

  19. Energy conversion evolution at lunar polar sites

    Indian Academy of Sciences (India)

    James D Burke

    2005-12-01

    Lunar polar environments have many advantages from the standpoint of energy supply to robotic and human surface bases.Sunlight is nearly continuous and always horizontal at peaks of perpetual light,while waste heat rejection is aided by the existence of cold,permanently shadowed regions nearby.In this paper a possible evolution of lunar polar energy systems will be described,beginning with small robotic photovoltaic landers and continuing into the development of increasingly powerful and diverse energy installations to provide not only electric power but also piped-in sunlight,air conditioning and high-temperature process heat.

  20. Cogeneration Technology Alternatives Study (CTAS). Volume 4: Energy conversion systems

    Science.gov (United States)

    Brown, D. H.; Gerlaugh, H. E.; Priestley, R. R.

    1980-01-01

    Industrial processes from the largest energy consuming sectors were used as a basis for matching a similar number of energy conversion systems that are considered as candidate which can be made available by the 1985 to 2000 time period. The sectors considered included food, textiles, lumber, paper, chemicals, petroleum, glass, and primary metals. The energy conversion systems included steam and gas turbines, diesels, thermionics, stirling, closed-cycle and steam injected gas turbines, and fuel cells. Fuels considered were coal, both coal and petroleum-based residual and distillate liquid fuels, and low Btu gas obtained through the on-site gasification of coal. An attempt was made to use consistent assumptions and a consistent set of ground rules specified by NASA for determining performance and cost. The advanced and commercially available cogeneration energy conversion systems studied in CTAS are fined together with their performance, capital costs, and the research and developments required to bring them to this level of performance.

  1. French work on ocean thermal energy conversion

    Science.gov (United States)

    Marchand, P.

    The ocean is discussed as a world-wide potential source of renewable energy, with special attention given to the 'deposit' of ocean thermal energy, which is determined by the temperature difference existing between surface water and that at a depth of 1000 m. A brief history of work done in France is presented, and mention is made of the work of d'Arsonval (1881), Claude and Boucherot (1926), and of projects, such as those at Abidjan and Guadeloupe. Attention is given to the French ocean thermal energy sites, to the Empain-Schneider closed-cycle studies, and the open-cycle floating ocean thermal energy station, with a discussion of thermodynamic considerations and cold water pipes. Problems and prospects are reviewed.

  2. Emerging electrochemical energy conversion and storage technologies

    Science.gov (United States)

    Badwal, Sukhvinder; Giddey, Sarbjit; Munnings, Christopher; Bhatt, Anand; Hollenkamp, Tony

    2014-09-01

    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.

  3. 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.

  4. Wind Energy Conversion Systems. A Unit of Instruction.

    Science.gov (United States)

    Greenwald, Martin

    The number of secondary schools, colleges, and universities offering courses in wind energy machine construction, repair, and installation, continues to increase. It is the purpose of this unit to include the study of wind energy conversion systems (WECS) as an integral part of related vocational and technical curriculum materials. The unit's…

  5. Low to high temperature energy conversion system

    Science.gov (United States)

    Miller, C. G. (Inventor)

    1977-01-01

    A method for converting heat energy from low temperature heat sources to higher temperature was developed. It consists of a decomposition chamber in which ammonia is decomposed into hydrogen and nitrogen by absorbing heat of decomposition from a low temperature energy source. A recombination reaction then takes place which increases the temperature of a fluid significantly. The system is of use for the efficient operation of compact or low capital investment turbine driven electrical generators, or in other applications, to enable chemical reactions that have a critical lower temperature to be used. The system also recovers heat energy from low temperature heat sources, such as solar collectors or geothermal sources, and converts it to high temperatures.

  6. Geomagnetic activity effects on plasma sheet energy conversion

    Directory of Open Access Journals (Sweden)

    M. Hamrin

    2010-10-01

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

  7. Energy Conversion 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.

  8. Conversion of solar energy into heat

    International Nuclear Information System (INIS)

    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

  9. CONVERSION EFFICIENCY IMPROVEMENT FOR ENERGY CONSERVATION USING MATRIX CONVERTER

    Directory of Open Access Journals (Sweden)

    G.N. SURYA

    2012-04-01

    Full Text Available Efficient conversion of electrical energy from one form to another has always been a fascinating domain for researchers. Right from the era of mercury arc rectifiers to present AC-DC-AC two stage converters and cycloconverters, efforts are consistently being laid to minimize the losses involved in conversion process. In the present study the AC-AC conversion topology known as Matrix Converter (MC, is modeled using MATLAB. Venturini’s simplified algorithm is used to determine the switch modulation duty cycle. The model is designedfor conversion of 50 Hz input frequency to 100 Hz and 25 Hz, using a simplified switch modulation strategy. The waveforms generated by MATLAB/simulink confirm the reduction of conversion losses by 12% to 15% with use of proposed model as compared to conventional (PWM converters. It is not intended in this study just to list out various works done so for but to establish the brevity of fundamental concept representing the simplified design along with its application areas mainly the VFDs and Wind Energy Conversion Systems (WECS. The model has also been tested for control of induction motor with 100 HZ and 25 Hz output frequencies. The waveforms of changed frequencies and reduced losses confirm the results anticipated at design stage.

  10. 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 overtopping...... 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...

  11. 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

  12. 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.

  13. 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. PMID:25017125

  14. 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.

  15. Chemoelectrical energy conversion of adenosine triphosphate

    Science.gov (United States)

    Sundaresan, Vishnu Baba; Sarles, Stephen Andrew; Leo, Donald J.

    2007-04-01

    Plant and animal cell membranes transport charged species, neutral molecules and water through ion pumps and channels. The energy required for moving species against established concentration and charge gradients is provided by the biological fuel - adenosine triphosphate (ATP) -synthesized within the cell. The adenosine triphosphatase (ATPases) in a plant cell membrane hydrolyze ATP in the cell cytoplasm to pump protons across the cell membrane. This establishes a proton gradient across the membrane from the cell exterior into the cell cytoplasm. This proton motive force stimulates ion channels that transport nutrients and other species into the cell. This article discusses a device that converts the chemical energy stored in adenosine triphosphate into electrical power using a transporter protein, ATPase. The V-type ATPase proteins used in our prototype are extracted from red beet(Beta vulgaris) tonoplast membranes and reconstituted in a bilayer lipid membrane or BLM formed from POPC and POPS lipids. A pH7 medium that can support ATP hydrolysis is provided on both sides of the membrane and ATP is dissolved in the pH7 buffer on one side of the membrane. Hydrolysis of ATP results in the formation of a phosphate ion and adenosine diphosphate. The energy from the reaction activates ATPase in the BLM and moves a proton across the membrane. The charge gradient established across the BLM due to the reaction and ion transport is converted into electrical current by half-cell reference electrodes. The prototype ATPase cell with an effective BLM area of 4.15 mm2 carrying 15 μl of ATPase proteins was observed to develop a steady state peak power output of 70 nW, which corresponds to a specific power of 1.69 μW/cm2 and a current density of 43.4 μA/cm2 of membrane area.

  16. 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.

  17. Mesoporous materials for energy conversion and storage devices

    Science.gov (United States)

    Li, Wei; Liu, Jun; Zhao, Dongyuan

    2016-06-01

    To meet the growing energy demands in a low-carbon economy, the development of new materials that improve the efficiency of energy conversion and storage systems is essential. Mesoporous materials offer opportunities in energy conversion and storage applications owing to their extraordinarily high surface areas and large pore volumes. These properties may improve the performance of materials in terms of energy and power density, lifetime and stability. In this Review, we summarize the primary methods for preparing mesoporous materials and discuss their applications as electrodes and/or catalysts in solar cells, solar fuel production, rechargeable batteries, supercapacitors and fuel cells. Finally, we outline the research and development challenges of mesoporous materials that need to be overcome to increase their contribution in renewable energy applications.

  18. 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.

  19. SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Steven Shaffer; Sean Kelly; Subhasish Mukerjee; David Schumann; H. Skip Mieney

    2003-06-09

    The objective of Phase I under this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with piped-in water (Demonstration System A); and Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine. This technical progress report covers work performed by Delphi from July through December 2002 under Department of Energy Cooperative Agreement DE-FC-02NT41246 for the 5 kW mass-market automotive (gasoline) auxiliary power unit. This report highlights technical results of the work performed under the following tasks for the automotive 5 kW system: Task 1--System Design and Integration; Task 2--Solid Oxide Fuel Cell Stack Developments; Task 3--Reformer Developments; Task 4--Development of Balance of Plant (BOP) Components; Task 5--Manufacturing Development (Privately Funded); Task 6--System Fabrication; and Task 7--System Testing.

  20. Efficient Photoelectrochemical Energy Conversion using Spinach Photosystem II (PSII) in Lipid Multilayer Films

    OpenAIRE

    Zhang, Yun; Magdaong, Nikki M.; Shen, Min; Frank, Harry A.; Rusling, James F.

    2014-01-01

    The need for clean, renewable energy has fostered research into photovoltaic alternatives to silicon solar cells. Pigment–protein complexes in green plants convert light energy into chemical potential using redox processes that produce molecular oxygen. Here, we report the first use of spinach protein photosystem II (PSII) core complex in lipid films in photoelectrochemical devices. Photocurrents were generated from PSII in a ∼2 μm biomimetic dimyristoylphosphatidylcholine (DMPC) film on a py...

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

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a new class of switching-mode audio power amplifiers, which are capable of direct energy conversion from the AC mains to the audio output. They represent an ultimate integration of a switching-mode power supply and a Class D audio power amplifier, where the intermediate DC bus...

  2. 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.

  3. 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.

  4. Energy conversion/power plant cost-cutting

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, K.

    1996-12-31

    This presentation by Kenneth Nichols, Barber-Nichols, Inc., is about cost-cutting in the energy conversion phase and power plant phase of geothermal energy production. Mr. Nichols discusses several ways in which improvements could be made, including: use of more efficient compressors and other equipment as they become available, anticipating reservoir resource decline and planning for it, running smaller binary systems independent of human operators, and designing plants so that they are relatively maintenance-free.

  5. Saturation and energy-conversion efficiency of auroral kilometric radiation

    Science.gov (United States)

    Wu, C. S.; Tsai, S. T.; Xu, M. J.; Shen, J. W.

    1981-01-01

    A quasi-linear theory is used to study the saturation level of the auroral kilometric radiation. The investigation is based on the assumption that the emission is due to a cyclotron maser instability as suggested by Wu and Lee and Lee et al. The thermodynamic bound on the radiation energy is also estimated separately. The energy-conversion efficiency of the radiation process is discussed. The results are consistent with observations.

  6. Dynamics and control: energy conversion, delivery, and demand analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, K.C.

    1979-04-01

    Techniques of mathematical modeling and modern control theory, using microprocessors and advanced measurement and control devices, are extensively applied to components and systems for the conversion and delivery of energy. The projection of energy demands, as a function of economic growth and energy price, is also the subject of active research and analysis. This position paper reviews the current state-of-the-art of analysis in these areas dealing with the planning and operation of energy systems that deliver fuels and electric power. Future research directions are also discussed. 25 references.

  7. 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.

  8. Future of photovoltaic energy conversion in developing countries

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, S.

    1980-04-01

    Recent studies reveal that photovoltaic energy conversion will be economically viable for usage in developing countries. An overview of programs designed to lower the costs of such conversion systems is presented. Government goals are reviewed, as well as application projects relative to rural usage. A summary of the state-of-the-art in both advanced research and commercially available technology is presented. It is concluded that with the range of the work being done, such systems will be viable for many rural applications within 5 years.

  9. SPS energy conversion and power management workshop. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    In 1977 a four year study, the concept Development and Evaluation Program, was initiated by the US Department of Energy and the National Aeronautics and Space Administration. As part of this program, a series of peer reviews were carried out within the technical community to allow available information on SPS to be sifted, examined and, if need be, challenged. The SPS Energy Conversion and Power Management Workshop, held in Huntsville, Alabama, February 5 to 7, 1980, was one of these reviews. The results of studies in this particular field were presented to an audience of carefully selected scientists and engineers. This first report summarizes the results of that peer review. It is not intended to be an exhaustive treatment of the subject. Rather, it is designed to look at the SPS energy conversion and power management options in breadth, not depth, to try to foresee any troublesome and/or potentially unresolvable problems and to identify the most promising areas for future research and development. Topics include photovoltaic conversion, solar thermal conversion, and electric power distribution processing and power management. (WHK)

  10. Renewable energy obtained by thermochemical conversion of biomass and wastes

    International Nuclear Information System (INIS)

    Full text: The production of energy from alternative sources is one of the main strategic tools for the sustainable development of modern society. In this regard, different kinds of biomass and wastes can contribute to the production of energy by means of chemical, thermal and biological processes. Energy technologies based on biomass and waste are undergoing rapid development: processes are optimized, new ideas are proposed for technical application. Despite the growing interest for the use of these technologies, in many countries their implementation still is at a low level, mainly for reasons other than technical and economical (i.e., low public acceptability, bad experience from the past, insufficient knowledge and experience, and others). Due to the wide range of feedstocks, biomass has a broad geographic distribution, in some cases offering a least-cost and near-term alternative. Renewable sources of energy will have a major role to the energy balance in upcoming years. Romania has an important renewable energy potential in solar, wind energy and biomass and offers utilization availabilities at local and national level. The 'Strategy of capitalizing renewable energy sources', drawn up by the Ministry of Economy and Commerce proposes year 2015 as target for the share of renewable sources to reach about 10-12 % of the overall energy supply. Thermochemical biomass conversion does include a number of possible roots to produce useful fuels and chemicals from the initial biomass feedstock. The basis of thermochemical conversion is the pyrolysis process. This paper focuses on this process in order to produce gas mixtures with high H2 content as the main products, significant amounts of liquid and a reactive carbon-rich char as the main by-products.The relationship between the composition of the starting materials, the process conditions and the desired product yields has also investigated to find out what are the optimum parameters of thermochemical conversion

  11. Thermionic emission energy distribution from nanocrystalline diamond films for direct thermal-electrical energy conversion applications

    OpenAIRE

    Uppireddi, Kishore; Westover, Tyler; Fisher, Timothy; Weiner, Brad; Morell, Gerardo

    2009-01-01

    In the ongoing quest for energy production by nonconventional methods, energy conversion by vacuum and solid-state thermionic emission devices is one of the potentially efficient pathways for converting thermal energy directly into electrical power. The realization of practical of thermionic energy conversion devices strongly depends on achieving low work function materials, which is thus far a limiting factor. In an attempt to develop a new low work function thermionic material, this work re...

  12. Photon energy conversion efficiency in gamma-ray spectrometry.

    Science.gov (United States)

    Švec, Anton

    2016-01-01

    Photon energy conversion efficiency coefficient is presented as the ratio of total energy registered in the collected spectrum to the emitted photon energy. This parameter is calculated from the conventional gamma-ray histogram and in principle is not affected by coincidence phenomena. This feature makes it particularly useful for calibration and measurement of radionuclide samples at close geometries. It complements the number of efficiency parameters used in gamma-ray spectrometry and can partly change the view as to how the gamma-ray spectra are displayed and processed.

  13. 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

  14. 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.

  15. Buckled graphene for efficient energy harvest, storage and conversion

    Science.gov (United States)

    Jiang, Jin-Wu

    2016-10-01

    Buckling is one of the most common phenomena in atom-thick layered structures like graphene. While the buckling phenomenon usually causes disaster for most nanodevices, we illustrate one positive application of buckled graphene for energy harvest, storage and conversion. More specifically, we perform molecular dynamical simulations to show that buckled graphene can be used to collect wasted mechanical energy and store the energy in the form of internal knotting potential. Through strain engineering, the knotting potential can be converted into useful kinetic (thermal) energy that is highly concentrated at the free edges of buckled graphene. The present study demonstrates potential applications of buckled graphene for converting dispersed wasted mechanical energy into concentrated useful kinetic (thermal) energy.

  16. Buckled graphene for efficient energy harvest, storage and conversion.

    Science.gov (United States)

    Jiang, Jin-Wu

    2016-10-01

    Buckling is one of the most common phenomena in atom-thick layered structures like graphene. While the buckling phenomenon usually causes disaster for most nanodevices, we illustrate one positive application of buckled graphene for energy harvest, storage and conversion. More specifically, we perform molecular dynamical simulations to show that buckled graphene can be used to collect wasted mechanical energy and store the energy in the form of internal knotting potential. Through strain engineering, the knotting potential can be converted into useful kinetic (thermal) energy that is highly concentrated at the free edges of buckled graphene. The present study demonstrates potential applications of buckled graphene for converting dispersed wasted mechanical energy into concentrated useful kinetic (thermal) energy.

  17. Thermoelectric Energy Conversion: Future Directions and Technology Development Needs

    Science.gov (United States)

    Fleurial, Jean-Pierre

    2007-01-01

    This viewgraph presentation reviews the process of thermoelectric energy conversion along with key technology needs and challenges. The topics include: 1) The Case for Thermoelectrics; 2) Advances in Thermoelectrics: Investment Needed; 3) Current U.S. Investment (FY07); 4) Increasing Thermoelectric Materials Conversion Efficiency Key Science Needs and Challenges; 5) Developing Advanced TE Components & Systems Key Technology Needs and Challenges; 6) Thermoelectrics; 7) 200W Class Lightweight Portable Thermoelectric Generator; 8) Hybrid Absorption Cooling/TE Power Cogeneration System; 9) Major Opportunities in Energy Industry; 10) Automobile Waste Heat Recovery; 11) Thermoelectrics at JPL; 12) Recent Advances at JPL in Thermoelectric Converter Component Technologies; 13) Thermoelectrics Background on Power Generation and Cooling Operational Modes; 14) Thermoelectric Power Generation; and 15) Thermoelectric Cooling.

  18. 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.

  19. Spectral light management for solar energy conversion systems

    Directory of Open Access Journals (Sweden)

    Stanley Cameron

    2016-06-01

    Full Text Available Due to the inherent broadband nature of the solar radiation, combined with the narrow spectral sensitivity range of direct solar to electricity devices, there is a massive opportunity to manipulate the solar spectrum to increase the functionality and efficiency of solar energy conversion devices. Spectral splitting or manipulation facilitates the efficient combination of both high-temperature solar thermal systems, which can absorb over the entire solar spectrum to create heat, and photovoltaic cells, which only convert a range of wavelengths to electricity. It has only recently been possible, with the development of nanofabrication techniques, to integrate micro- and nano-photonic structures as spectrum splitters/manipulators into solar energy conversion devices. In this paper, we summarize the recent developments in beam splitting techniques, and highlight some relevant applications including combined PV-thermal collectors and efficient algae production, and suggest paths for future development in this field.

  20. Spectral light management for solar energy conversion systems

    Science.gov (United States)

    Stanley, Cameron; Mojiri, Ahmad; Rosengarten, Gary

    2016-06-01

    Due to the inherent broadband nature of the solar radiation, combined with the narrow spectral sensitivity range of direct solar to electricity devices, there is a massive opportunity to manipulate the solar spectrum to increase the functionality and efficiency of solar energy conversion devices. Spectral splitting or manipulation facilitates the efficient combination of both high-temperature solar thermal systems, which can absorb over the entire solar spectrum to create heat, and photovoltaic cells, which only convert a range of wavelengths to electricity. It has only recently been possible, with the development of nanofabrication techniques, to integrate micro- and nano-photonic structures as spectrum splitters/manipulators into solar energy conversion devices. In this paper, we summarize the recent developments in beam splitting techniques, and highlight some relevant applications including combined PV-thermal collectors and efficient algae production, and suggest paths for future development in this field.

  1. Platinum nanoparticle decorated silicon nanowires for efficient solar energy conversion.

    Science.gov (United States)

    Peng, Kui-Qing; Wang, Xin; Wu, Xiao-Ling; Lee, Shuit-Tong

    2009-11-01

    High-density aligned n-type silicon nanowire (SiNW) arrays decorated with discrete 5-10 nm platinum nanoparticles (PtNPs) have been fabricated by aqueous electroless Si etching followed by an electroless platinum deposition process. Coating of PtNPs on SiNW sidewalls yielded a substantial enhancement in photoconversion efficiency and an apparent energy conversion efficiency of up to 8.14% for the PtNP-decorated SiNW-based photoelectrochemical solar cell using a liquid electrolyte containing Br(-)/Br(2) redox couple. The results demonstrate PtNP-decorated SiNWs to be a promising hybrid system for solar energy conversion. PMID:19807069

  2. Design of nitride semiconductors for solar energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Zakutayev, Andriy

    2016-01-01

    Nitride semiconductors are a promising class of materials for solar energy conversion applications, such as photovoltaic and photoelectrochemical cells. Nitrides can have better solar absorption and electrical transport properties than the more widely studied oxides, as well as the potential for better scalability than other pnictides or chalcogenides. In addition, nitrides are also relatively unexplored compared to other chemistries, so they provide a great opportunity for new materials discovery. This paper reviews the recent advances in the design of novel semiconducting nitrides for solar energy conversion technologies. Both binary and multinary nitrides are discussed, with a range of metal chemistries (Cu3N, ZnSnN2, Sn3N4, etc.) and crystal structures (delafossite, perovskite, spinel, etc.), including a brief overview of wurtzite III-N materials and devices. The current scientific challenges and promising future directions in the field are also highlighted.

  3. 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)

  4. Carbon-based electrocatalysts for advanced energy conversion and storage

    OpenAIRE

    Zhang, Jintao; Xia, Zhenhai; Dai, Liming

    2015-01-01

    Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play curial roles in electrochemical energy conversion and storage, including fuel cells and metal-air batteries. Having rich multidimensional nanoarchitectures [for example, zero-dimensional (0D) fullerenes, 1D carbon nanotubes, 2D graphene, and 3D graphite] with tunable electronic and surface characteristics, various carbon nanomaterials have been demonstrated to act as efficient metal-free electrocatalysts for ORR and OER ...

  5. Black nickel-cobalt selective coatings for solar energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, K.N.; Selvam, M.; Shenoi, B.A.; Shanmugam, N.V.; John, S.; Annamalai, M.; Iyer, M.V.; Nirmala, K.A.; Venkatesh, P.; Prasad, C.R.; Subramani, C.

    1982-01-01

    The development of black nickel-cobalt selective coating for solar energy conversion is reported. This coating has been produced by plating nickel-cobalt alloy from suitable electrolyte and then immersion blackening in weak sulphuric acid. The effect of plating time, current density and immersion time, in acid with respect to absorptance and emittance were studied. Thermal cycling test and stagnation temperature measurement was also carried out.

  6. Spectral light management for solar energy conversion systems

    OpenAIRE

    Stanley Cameron; Mojiri Ahmad; Rosengarten Gary

    2016-01-01

    Due to the inherent broadband nature of the solar radiation, combined with the narrow spectral sensitivity range of direct solar to electricity devices, there is a massive opportunity to manipulate the solar spectrum to increase the functionality and efficiency of solar energy conversion devices. Spectral splitting or manipulation facilitates the efficient combination of both high-temperature solar thermal systems, which can absorb over the entire solar spectrum to create heat, and photovolta...

  7. ady State Analysis of Grid Connected Hybrid Renewable Energy Conversion Systems

    OpenAIRE

    DR.D. PADMA SUBRAMANIAN

    2014-01-01

    This paper presents an analysis on steady state behavior of grid connected hybrid renewable energy conversion systems (RECS). Modeling of Doubly Fed Induction Generator (DFIG) for Wind Energy Conversion system (WECS) and marine current energy system ,and modeling of PV module is presented. A procedure for incorporating WECS, marine current energy conversion system and solar energy conversion system into a power flow program is discussed. A gird interfaced power flow program is...

  8. Plasmonic Nanomaterials for Optical-to-Electrical Energy Conversion

    Science.gov (United States)

    Sheldon, Matthew

    High-quality semiconductor solids have been the dominant photovoltaic materials platform for decades. Although several alternative approaches have been proposed, e.g. dye-sensitized cells or polymeric solids, none compete in terms of cost and conversion efficiency, the crucial benchmarks for industrial scale implementation. However, semiconductors suffer from several fundamental limitations relating to the microscopic mechanism of power conversion that preclude them, even theoretically, from achieving conversion efficiency at the Carnot limit of 95%. Indeed, the fundamentally different tasks of semiconductors in photovoltaic devices, both as optical absorbers, and separately, for electron-hole pair separation and collection, often demand opposing trade-offs in materials optimization. Alternatively, recent advances in subwavelength metal optics, e.g. nanophotonics, metamaterials, and plasmonics, provide several new examples where nanostructured metals perform the separate tasks of absorption and charge separation necessary for photovoltaic power conversion. Nanostructured metals are extremely efficient broadband absorbers of radiation, with tailorable optical properties throughout the visible and infrared spectrum. It is traditionally assumed that the lack of a band gap and consequent fast electronic relaxation (fs) and short mean free path (100 nm) hinders efficient carrier collection. However, new phenomena resulting from the remarkable energy concentration and nanoscale collection geometry afforded by plasmonic systems suggest new strategies may be possible that use all metal structures. In this talk, I will describe two ongoing studies in our laboratory that exemplify opportunities for metal-based optical energy conversion: (1) Excitation with circularly polarized illumination can induce strong, persistent electrical drift currents in resonant metal nanostructures via the inverse faraday effect. (2) Plasmonic absorption in metal nanostructures provides an

  9. Energy transmission from ocean thermal energy conversion plants

    Energy Technology Data Exchange (ETDEWEB)

    Konopka, A.; Talib, A.; Yudow, B.; Biederman, N.

    1976-01-01

    This paper compares the transmission, by barge and pipeline, of gaseous hydrogen, liquid hydrogen, and ammonia, as energy carriers, with transmission of electricity in submarine cables from an OTEC plant. Because hydrogen energy and electrical energy are not equivalent, comparison requires assuming the outputs are converted to a common form. Thus, we present the delivered cost and overall energy efficiency of hydrogen, ammonia, and electricity as well as a discussion of the equipment, costs and efficiencies of converting hydrogen and ammonia into electricity, and OTEC mechanical energy into hydrogen and ammonia. Converting electricity to chemical commodities and energies was not assessed.

  10. 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.

  11. Applied research on energy storage and conversion for photovoltaic and wind energy systems. Volume III. Wind conversion systems with energy storage. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    The variability of energy output inherent in wind energy conversion systems (WECS) has led to the investigation of energy storage as a means of managing the available energy when immediate, direct use is not possible or desirable. This portion of the General Electric study was directed at an evaluation of those energy storage technologies deemed best suited for use in conjunction with a wind energy conversion system in utility, residential and intermediate applications. Break-even cost goals are developed for several storage technologies in each application. These break-even costs are then compared with cost projections presented in Volume I of this report to show technologies and time frames of potential economic viability. The report summarizes the investigations performed and presents the results, conclusions and recommendations pertaining to use of energy storage with wind energy conversion systems.

  12. Biomimetic Flow Sensors

    NARCIS (Netherlands)

    Casas, J.; Liu, Chang; Krijnen, G.J.M.

    2012-01-01

    Biomimetic flow sensors are biologically inspired devices that measure the speed and direction of fluids. This survey starts by describing the role and functioning of airflow-sensing hairs in arthropods and in fishes, carries on with the biomimetic MEMS implementations, both for air and water flow s

  13. Biomimetic Production of Hydrogen

    Science.gov (United States)

    Gust, Devens

    2004-03-01

    The basic reaction for hydrogen generation is formation of molecular hydrogen from two electrons and two protons. Although there are many possible sources for the protons and electrons, and a variety of mechanisms for providing the requisite energy for hydrogen synthesis, the most abundant and readily available source of protons and electrons is water, and the most attractive source of energy for powering the process is sunlight. Not surprisingly, living systems have evolved to take advantage of these sources for materials and energy. Thus, biology provides paradigms for carrying out the reactions necessary for hydrogen production. Photosynthesis in green plants uses sunlight as the source of energy for the oxidation of water to give molecular oxygen, protons, and reduction potential. Some photosynthetic organisms are capable of using this reduction potential, in the form of the reduced redox protein ferredoxin, to reduce protons and produce molecular hydrogen via the action of an hydrogenase enzyme. A variety of other organisms metabolize the reduced carbon compounds that are ultimately the major products of photosynthesis to produce molecular hydrogen. These facts suggest that it might be possible to use light energy to make molecular hydrogen via biomimetic constructs that employ principles similar to those used by natural organisms, or perhaps with hybrid "bionic" systems that combine biomimetic materials with natural enzymes. It is now possible to construct artificial photosynthetic systems that mimic some of the major steps in the natural process.(1) Artificial antennas based on porphyrins, carotenoids and other chromophores absorb light at various wavelengths in the solar spectrum and transfer the harvested excitation energy to artificial photosynthetic reaction centers.(2) In these centers, photoinduced electron transfer uses the energy from light to move an electron from a donor to an acceptor moiety, generating a high-energy charge-separated state

  14. Environmental Protection Legislation on China’s Energy Development and In-situ Conversion

    Institute of Scientific and Technical Information of China (English)

    NAN Jing-yu

    2012-01-01

    China’s poor energy development and in-situ conversion legislation, environment laws and energy laws lead to a severe environmental issue in energy source. This paper uses comparison and logical methods to discuss Chapter 4 of Energy Law (Draft for Soliciting Opinions). Energy development is taken as a separate chapter; in-situ energy conversion is added to energy processing and conversion, common features are summarized to form general provisions and other provisions. According to respective characteristics of system for total amount control of energy development, performance guarantee system, environmental trust fund system, energy retaining system and environmental lien system, incorporate them into energy development, in-situ energy conversion and energy processing and conversion, in the hope of solving China’s shortage of supply for environmental protection laws on energy development and in-situ conversion, responding to times of environmental protection, and optimizing China’s Energy Law.

  15. Biological and Biomimetic Low-Temperature Routes to Materials for Energy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Morse, Daniel E. [Univ. of California, Santa Barbara, CA (United States). Inst. for Collaborative Biotechnologies

    2016-08-29

    New materials are needed to significantly improve the efficiencies of energy harnessing, transduction and storage, yet the synthesis of advanced composites and multi-metallic semiconductors with nanostructures optimized for these functions remains poorly understood and even less well controlled. To help address this need, we proposed three goals: (1) to further investigate the hierarchical structure of the biologically synthesized silica comprising the skeletal spicules of sponges that we discovered, to better resolve the role and mechanism of templating by the hierarchically assembled silicatein protein filament; (2) to extend our molecular and genetic analyses and engineering of silicatein, the self-assembling, structure-directing, silica-synthesizing enzyme we discovered and characterized, to better understand and manipulate the catalysis and templating of semiconductor synthesis,; and (3) to further investigate, scale up and harness the biologically inspired, low-temperature, kinetically controlled catalytic synthesis method we developed (based on the mechanism we discovered in silicatein) to investigate the kinetic control of the structure-function relationships in magnetic materials, and develop new materials for energy applications. The bio-inspired catalytic synthesis method we have developed is low-cost, low temperature, and operates without the use of polluting chemicals. In addition to direct applications for improvement of batteries and fuel cells, the broader impact of this research includes a deeper fundamental understanding of the factors governing kinetically controlled synthesis and its control of the emergent nanostructure and performance of a wide range of nanomaterials for energy applications.

  16. 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.

  17. 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

  18. Investigation of direct solar-to-microwave energy conversion techniques

    Science.gov (United States)

    Chatterton, N. E.; Mookherji, T. K.; Wunsch, P. K.

    1978-01-01

    Identification of alternative methods of producing microwave energy from solar radiation for purposes of directing power to the Earth from space is investigated. Specifically, methods of conversion of optical radiation into microwave radiation by the most direct means are investigated. Approaches based on demonstrated device functioning and basic phenomenologies are developed. There is no system concept developed, that is competitive with current baseline concepts. The most direct methods of conversion appear to require an initial step of production of coherent laser radiation. Other methods generally require production of electron streams for use in solid-state or cavity-oscillator systems. Further development is suggested to be worthwhile for suggested devices and on concepts utilizing a free-electron stream for the intraspace station power transport mechanism.

  19. Efficient computerized model for dynamic analysis of energy conversion systems

    Science.gov (United States)

    Hughes, R. D.; Lansing, F. L.; Khan, I. R.

    1983-02-01

    In searching for the optimum parameters that minimize the total life cycle cost of an energy conversion system, various combinations of components are examined and the resulting system performance and associated economics are studied. The systems performance and economics simulation computer program (SPECS) was developed to fill this need. The program simulates the fluid flow, thermal, and electrical characteristics of a system of components on a quasi-steady state basis for a variety of energy conversion systems. A unique approach is used in which the set of characteristic equations is solved by the Newton-Raphson technique. This approach eliminates the tedious iterative loops which are found in comparable programs such as TRNSYS or SOLTES-1. Several efficient features were also incorporated such as the centralized control and energy management scheme, and analogous treatment of energy flow in electrical and mechanical components, and the modeling of components of similar fundamental characteristics using generic subroutines. Initial tests indicate that this model can be used effectively with a relatively small number of time steps and low computer cost.

  20. 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 $Delta E = A ub c^{2}Delta M$.

  1. Development of a high-energy distributed energy source electromagnetic railgun with improved energy conversion efficiency

    International Nuclear Information System (INIS)

    Vought Corporation in cooperation with the Center for Electromechanics at the University of Texas (CEM-UT) has developed under sponsorship by the Defense Advanced Research Projects Agency (DARPA) and the Army Armament, Munitions, and Chemical Command (AMCCOM) a high-energy distributed energy source (DES) electromagnetic (EM) railgun accelerator. This paper discusses the development and current status of the DES railgun which has the design capability to launch projectile masses up to 60 grams to the 3-4 km/sec velocity regime with energy conversion efficiencies above 35 percent. These goals are being accomplished through utilization of scaled-energy CEM-UT railgun experiments for sequenced timing/staging and a full energy (575 kJ) design at Vought for high efficiency capability. The operational Vought single-pulse railgun forms the baseline for the full energy testing

  2. Multi-objective design and optimization of district energy systems including polygeneration energy conversion technologies

    OpenAIRE

    Weber, Céline Isabelle

    2008-01-01

    In the present context of finding ways to decrease CO2 emissions linked with human activity, district energy systems including polygeneration energy conversion technologies are likely to play a major role. District energy systems meet the heating, hot water, cooling and electricity requirements of a district. Because they meet several types of energy requirements, and for more than one single building, district energy systems represent good opportunities to implement polygeneration energy con...

  3. 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

  4. 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.

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

    Science.gov (United States)

    Corr, L. R.; Ma, D. T.

    2016-08-01

    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.

  6. Functional interfaces for biomimetic energy harvesting: CNTs-DNA matrix for enzyme assembly.

    Science.gov (United States)

    Hjelm, Rachel M E; Garcia, Kristen E; Babanova, Sofia; Artyushkova, Kateryna; Matanovic, Ivana; Banta, Scott; Atanassov, Plamen

    2016-05-01

    The development of 3D structures exploring the properties of nano-materials and biological molecules has been shown through the years as an effective path forward for the design of advanced bio-nano architectures for enzymatic fuel cells, photo-bio energy harvesting devices, nano-biosensors and bio-actuators and other bio-nano-interfacial architectures. In this study we demonstrate a scaffold design utilizing carbon nanotubes, deoxyribose nucleic acid (DNA) and a specific DNA binding transcription factor that allows for directed immobilization of a single enzyme. Functionalized carbon nanotubes were covalently bonded to a diazonium salt modified gold surface through carbodiimide chemistry creating a brush-type nanotube alignment. The aligned nanotubes created a highly ordered structure with high surface area that allowed for the attachment of a protein assembly through a designed DNA scaffold. The enzyme immobilization was controlled by a zinc finger (ZNF) protein domain that binds to a specific dsDNA sequence. ZNF 268 was genetically fused to the small laccase (SLAC) from Streptomyces coelicolor, an enzyme belonging to the family of multi-copper oxidases, and used to demonstrate the applicability of the developed approach. Analytical techniques such as X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and enzymatic activity analysis, allowed characterization at each stage of development of the bio-nano architecture. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson. PMID:26751397

  7. Innovative rubble mound breakwaters for wave energy conversion

    International Nuclear Information System (INIS)

    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

  8. Electrothermal energy conversion using electron gas volumetric change inside semiconductors

    Science.gov (United States)

    Yazawa, K.; Shakouri, A.

    2016-07-01

    We propose and analyze an electrothermal energy converter using volumetric changes in non-equilibrium electron gas inside semiconductors. The geometric concentration of electron gas under an electric field increases the effective pressure of the electrons, and then a barrier filters out cold electrons, acting like a valve. Nano- and micro-scale features enable hot electrons to arrive at the contact in a short enough time to avoid thermalization with the lattice. Key length and time scales, preliminary device geometry, and anticipated efficiency are estimated for electronic analogs of Otto and Brayton power generators and Joule-Thomson micro refrigerators on a chip. The power generators convert the energy of incident photons from the heat source to electrical current, and the refrigerator can reduce the temperature of electrons in a semiconductor device. The analytic calculations show that a large energy conversion efficiency or coefficient of performance may be possible.

  9. Effect of Conversion Efficiency on Gamma-Ray Burst Energy

    Institute of Scientific and Technical Information of China (English)

    Lei Xu; Zi-Gao Dai

    2004-01-01

    Beaming effect makes it possible that gamma-ray bursts have a standard energy,but the gamma-ray energy release is sensitive to some parameters.Our attention is focused on the effect of the gamma ray conversion efficiency(ηγ),which may range between 0.01 and 0.9,and which probably has a random value for different GRBs under certain conditions.Making use of the afterglow data from the literature,we carried out a complete correction to the conical opening angle formula.Within the framework of the conical jet model,we ran a simple Monte Carlo simulation for random values of ηγ,and found that the gamma-ray energy release is narrowly clustered,whether we use a constant value of ηγ or random values for different gamma-ray bursts.

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

    Science.gov (United States)

    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

    2016-10-01

    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.

  11. Solar energy conversion with photon-enhanced thermionic emission

    Science.gov (United States)

    Kribus, Abraham; Segev, Gideon

    2016-07-01

    Photon-enhanced thermionic emission (PETE) converts sunlight to electricity with the combined photonic and thermal excitation of charge carriers in a semiconductor, leading to electron emission over a vacuum gap. Theoretical analyses predict conversion efficiency that can match, or even exceed, the efficiency of traditional solar thermal and photovoltaic converters. Several materials have been examined as candidates for radiation absorbers and electron emitters, with no conclusion yet on the best set of materials to achieve high efficiency. Analyses have shown the complexity of the energy conversion and transport processes, and the significance of several loss mechanisms, requiring careful control of material properties and optimization of the device structure. Here we survey current research on PETE modeling, materials, and device configurations, outline the advances made, and stress the open issues and future research needed. Based on the substantial progress already made in this young topic, and the potential of high conversion efficiency based on theoretical performance limits, continued research in this direction is very promising and may yield a competitive technology for solar electricity generation.

  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. 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.; Lowther, S. E.; Lillehei, P. T.; Bryant, R. G.

    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.

  14. Modeling and analysis of DFIG in wind energy conversion system

    Directory of Open Access Journals (Sweden)

    Omer Elfaki Elbashir, Wang Zezhong, Liu Qihui

    2014-01-01

    Full Text Available This paper deals with the modeling, analysis, and simulation of a doubly-fed induction generator (DFIG driven by a wind turbine. The grid connected wind energy conversion system (WECS is composed of DFIG and two back to back PWM voltage source converters (VSCs in the rotor circuit. A machine model is derived in an appropriate dq reference frame. The grid voltage oriented vector control is used for the grid side converter (GSC in order to maintain a constant DC bus voltage, while the stator voltage orientated vector control is adopted in the rotor side converter (RSC to control the active and reactive powers.

  15. 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.

  16. Low cost composite materials for wind energy conversion systems

    Science.gov (United States)

    Weingart, O.

    1980-01-01

    A winding process utilizing a low-cost E-glass fabric called transverse-filament tape for low-cost production of wind turbine generators (WTG) is described. The process can be carried out continuously at high speed to produce large one-piece parts with tapered wall thicknesses on a tapered mandrel. It is being used to manufacture blades for the NASA/DOE 200-ft-diameter MOD-1 WTG and Rockwell/DOE 40-kW small wind energy conversion system (SWECS).

  17. 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

  18. Conversion of Concentrated Solar Thermal Energy into Chemical Energy

    Energy Technology Data Exchange (ETDEWEB)

    Tamaura, Yutaka (Dept. of Chemistry, Science and Engineering, Tokyo Inst. of Technology, Meguro-ku, Tokyo (Japan)), E-mail: ytamaura@chem.titech.ac.jp

    2012-03-15

    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/m2 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{sub 2} releasing reaction (alpha-O{sub 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{sub 2} gas formation from the O2- 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

  19. Energy and data conversion circuits for low power sensory systems

    Science.gov (United States)

    Ghosh, Suvradip

    This dissertation focuses on the problem of increasing the lifetime of wireless sensors. This problem is addressed from two different angles: energy harvesting and data compression. Energy harvesting enables a sensor to extract energy from its environment and use it to power itself or recharge its batteries. Data compression, on the other hand, allows a sensor to save energy by reducing the radio transmission bandwidth. This dissertation proposes a fractal-based photodiode fabricated on standard CMOS process as an energy harvesting device with increased efficiency. Experiments show that, the fractal based photodiodes are 6% more efficient compared to the conventional square shaped photodiode. The fractal shape photodiode has more perimeter-to-area ratio which increases the lateral response, improving its efficiency. With increased efficiency, more current is generated but the open-circuit voltage still remains low (0.3V--0.45V depending on illumination condition). These voltages have to be boosted up to higher values if they are going to be used to power up any sensory circuit or recharge a battery. We propose a switched-inductor DC-DC converter to boost the low voltage of the photodiodes to higher voltages. The proposed circuit uses two on-chip switches and two off-chip Components: an inductor and a capacitor. Experiments show a voltage up to 2.81V can be generated from a single photodiode of 1mm2 area. The voltage booster circuit achieved a conversion efficiency of 59%. Data compression was also explored in an effort to reduce energy consumption during radio transmission. An analog-to-digital converter (ADC), which can jointly perform the tasks of digital conversion and entropy encoding, has also been proposed in this dissertation. The joint data conversion/compression help savings in area and power resources, making it suitable for on-sensor compression. The proposed converter combines a cyclic converter architecture and Golomb-Rice entropy encoder. The

  20. Supercritical Carbon Dioxide Brayton Cycle Energy Conversion System

    International Nuclear Information System (INIS)

    This report contains the description of the S-CO2 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-CO2 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-CO2 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-CO2 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/CO2 boundary failure event, a computer was developed to simulate the complex thermodynamic behaviors coupled with the chemical reaction between liquid sodium and CO2 gas. The long term behavior of a Na/CO2 boundary failure event and its consequences which lead to a system pressure transient were evaluated

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

    International Nuclear Information System (INIS)

    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 (137Cs) and strontium (90Sr). The 137Cs and 90Sr 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. 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.

  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. PMID:26931884

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

    International Nuclear Information System (INIS)

    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/cm3 in less than 0,5 μs corresponding to an electrical horse-power superior to 2 MW/cm3. (author)

  6. Wave loadings acting on Overtopping Breakwater for Energy Conversion

    DEFF Research Database (Denmark)

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

    2013-01-01

    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......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...... the incoming wave to produce electricity. 2D hydraulic model tests were carried out at the Department of Civil Engineering, Aalborg University (Denmark). The analyses of hydraulic model tests have identified the main shapes assumed by wave surfaces at the breakwater and respective spatial and temporal pressure...

  7. 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.

  8. ECUT (Energy Conversion and Utilization Technologies) program: Biocatalysis Project

    Science.gov (United States)

    1988-03-01

    Fiscal year 1987 research activities and accomplishments for the Biocatalysis Project of the U.S. Department of Energy, Energy Conversion and Utilization Technologies (ECUT) Division are presented. The project's technical activities were organized into three work elements. The Molecular Modeling and Applied Genetics work element includes modeling and simulation studies to verify a dynamic model of the enzyme carboxypeptidase; plasmid stabilization by chromosomal integration; growth and stability characteristics of plasmid-containing cells; and determination of optional production parameters for hyper-production of polyphenol oxidase. 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. The Bioprocess Design and Assessment work element attempts to develop procedures (via user-friendly computer software) for assessing the economics and energetics of a given biocatalyst process.

  9. ECUT (Energy Conversion and Utilization Technologies) program: Biocatalysis Project

    Science.gov (United States)

    1988-01-01

    Fiscal year 1987 research activities and accomplishments for the Biocatalysis Project of the U.S. Department of Energy, Energy Conversion and Utilization Technologies (ECUT) Division are presented. The project's technical activities were organized into three work elements. The Molecular Modeling and Applied Genetics work element includes modeling and simulation studies to verify a dynamic model of the enzyme carboxypeptidase; plasmid stabilization by chromosomal integration; growth and stability characteristics of plasmid-containing cells; and determination of optional production parameters for hyper-production of polyphenol oxidase. 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. The Bioprocess Design and Assessment work element attempts to develop procedures (via user-friendly computer software) for assessing the economics and energetics of a given biocatalyst process.

  10. 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...

  11. All silicon electrode photocapacitor for integrated energy storage and conversion.

    Science.gov (United States)

    Cohn, Adam P; Erwin, William R; Share, Keith; Oakes, Landon; Westover, Andrew S; Carter, Rachel E; Bardhan, Rizia; Pint, Cary L

    2015-04-01

    We demonstrate a simple wafer-scale process by which an individual silicon wafer can be processed into a multifunctional platform where one side is adapted to replace platinum and enable triiodide reduction in a dye-sensitized solar cell and the other side provides on-board charge storage as an electrochemical supercapacitor. This builds upon electrochemical fabrication of dual-sided porous silicon and subsequent carbon surface passivation for silicon electrochemical stability. The utilization of this silicon multifunctional platform as a combined energy storage and conversion system yields a total device efficiency of 2.1%, where the high frequency discharge capability of the integrated supercapacitor gives promise for dynamic load-leveling operations to overcome current and voltage fluctuations during solar energy harvesting.

  12. 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.

  13. 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.

  14. Alkali layered compounds interfaces for energy conversion and energy storage

    Science.gov (United States)

    Papageorgopoulos, Chris A.

    1996-01-01

    During year one a new ultra-high vacuum, an Ar(+) ion sputterer, a low energy electron diffraction (LEED) system, an Auger electron spectrometer (AES), a work function measurement device with a Kelvin probe, and related accessories were used. The study found a focus in the adsorption of chalcogenides on Si and III-V compound semiconductors. In the second year, a scanning tunneling microscope was obtained along with a quadrapole mass spectrometer, power supplies, a computer, a chart recorder, etc. We started the systematic study on the adsorption of chalcogenides on the compound semiconductor surfaces. The third year saw the mounting of the scanning tunneling microscope (STM) on the existing UHV system. The investigation continued with the adsorption of Cs (alkali) on S-covered Si(100)2x1 surfaces. Then the adsorption of S on Cs-covered Si(100) surfaces was studied.

  15. Understanding and tuning nanostructured materials for chemical energy conversion

    Science.gov (United States)

    Jian, Guoqiang

    The conversion of energy that employs chemical reaction is termed chemical energy conversion. In my dissertation, I have focused on chemical energy conversion systems involving energetic materials and lithium ion batteries, where performance is strongly dependent on the properties of materials and their architecture. The objective of this study is to enhance our understanding and tuning of nanostructured materials that might find application toward energetic materials and electrode materials in lithium ion batteries. Rapid heating diagnostics tools, i.e. temperature-jump techniques, have been used to study the ignition of aluminum nanoparticles, nanothermite reaction mechanism and metal oxides nanoparticles decomposition under rapid heating conditions (˜105-106 K/s). Time-resolved mass spectra results support the hypothesis that Al containing species diffuse outwards through the oxide shell. Low effective activation energies were found for metal oxides nanoparticles decomposition at high heating rates, implying the mass transfer control at high heating rates. The role of oxygen release from oxidizer in nanothermite reactions have been examined for several different systems, including some using microsized oxidizer (i.e., nano-Al/micro-I 2O5). In particular, for periodate based nanothermites, direct evidence from high heating rate SEM and mass spectrometry results support that direct gas phase oxygen release from oxidizer decomposition is critical in its ignition and combustion. Efforts have also been made to synthesize nanostructured materials for nanoenergetic materials and lithium ion batteries applications. Hollow CuO spheres were synthesized by aerosol spray pyrolysis, employing a gas blowing mechanism for the formation of hollow structure during aerosol synthesis. The materials synthesized as oxidizers in nanothermite demonstrated superior performance, and of particular note, periodate salts based nanothermite demonstrated the best gas generating performance

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

    OpenAIRE

    Cheng-Tao Tsai

    2012-01-01

    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 an...

  17. Holey tungsten oxynitride nanowires: novel anodes efficiently integrate microbial chemical energy conversion and electrochemical energy storage.

    Science.gov (United States)

    Yu, Minghao; Han, Yi; Cheng, Xinyu; Hu, Le; Zeng, Yinxiang; Chen, Meiqiong; Cheng, Faliang; Lu, Xihong; Tong, Yexiang

    2015-05-20

    Holey tungsten oxynitride nanowires with superior conductivity, good biocompatibility, and good stability achieve excellent performance as anodes for both asymmetric supercapacitors and microbial fuel cells. Moreover, an innovative system is devised based on these as-prepared tungsten oxynitride anodes, which can simultaneously realize both energy conversion from chemical to electric energy and its storage. PMID:25854325

  18. ECUT (Energy Conversion and Utilization Technologies Program). Biocatalysis Project

    Science.gov (United States)

    1986-07-01

    Presented are the FY 1985 accomplishments, activities, and planned research efforts of the Biocatalysis Project of the U.S. Department of Energy, Energy Conversion and Utilization Technologies (ECUT) Program. The Project's technical activities were organized as follows: In the Molecular Modeling and Applied Genetics work element, research focused on (1) modeling and simulation studies to establish the physiological basis of high temperature tolerance in a selected enzyme and the catalytic mechanisms of three species of another enzyme, and (2) determining the degree of plasmid amplification and stability of several DNA bacterial strains. In the Bioprocess Engineering work element, research focused on (1) studies of plasmid propagation and the generation of models, (2) developing methods for preparing immobilized biocatalyst beads, and (3) developing an enzyme encapsulation method. In the Process Design and Analysis work element, research focused on (1) further refinement of a test case simulation of the economics and energy efficiency of alternative biocatalyzed production processes, (2) developing a candidate bioprocess to determine the potential for reduced energy consumption and facility/operating costs, and (3) a techno-economic assessment of potential advancements in microbial ammonia production.

  19. Self-supported electrocatalysts for advanced energy conversion processes

    Directory of Open Access Journals (Sweden)

    Tian Yi Ma

    2016-06-01

    Full Text Available The biggest challenge in developing new energy conversion technologies such as rechargeable metal-air batteries, regenerated fuel cells and water splitting devices is to find suitable catalysts that can efficiently and stably catalyze the key electrochemical processes involved. This paper reviews the new development of self-supported electrocatalysts in three categories: electrocatalysts growing on rigid substrates, electrocatalysts growing on soft substrates, and free-standing catalyst films. They are distinct and superior to the conventional powdery electrocatalysts, showing advantages in controllable nanostructure and chemical component, flexible electrode configuration, and outstanding catalytic performance. The self-supported electrocatalysts with various architectures like nanowire/plate/pillar arrays and porous films, composed of metals, metal oxides/selenides/phosphides, organic polymers, carbons and their corresponding hybrids, are presented and discussed. These catalysts exhibit high activity, durability and selectivity toward oxygen reduction, oxygen evolution, and/or hydrogen evolution reactions. The perspectives on the relevant areas are also proposed.

  20. 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.

  1. Current Source Converter Based Wind Energy Conversion Systems

    Institute of Scientific and Technical Information of China (English)

    Samir Kouro; Jing-ya DAI; Bin WU

    2011-01-01

    The increase in the installed capacity of wind energy conversion systems (WECS) has triggered the development of more demanding grid codes and additional requirements on performance.In order to meet these requirements the industry trend has shifted to full-scale power converter interfaces in modern multi-megawatt WECS.As consequence,a wide variety of new power converter topologies and WECS configurations have been introduced in recent years.Among them,current source converter(CSC) based configurations have attracted attention due to a series of advantages like:simple structure,grid friendly waveforms,controllable power factor,and reliable grid short-circuit protection.This paper presents the latest developments in CSC interfaces for WECS and related technologies such as modulation methods,control schemes and grid code compatibility.

  2. Comparison of Performances of Turbines for Wave Energy Conversion

    Institute of Scientific and Technical Information of China (English)

    Yoichi Kinoue; Toshiaki Setoguchi; Tomohiko Kuroda; Kenji Kaneko; Manabu Takao; Ajit Thakker

    2003-01-01

    The Wells turbine for a wave power generator is a self-rectifying air turbine that is available for an energy conversion in an oscillating water-air column without any rectifying valve. The objective of this paper is to compare the performances of the Wells turbines in which the profile of blade are NACA0020, NACA0015, CA9 and HSIM15-262123-1576 in the small-scale model testing. The running characteristics in the steady flow, the start and running characteristics in the sinusoidal flow and the hysteretic characteristics in the sinusoidal flow were investigated for four kinds of turbine. As a conclusion, the turbine in which the profile of blade is NACA0020 has the best performances among 4 turbines for the running and starting characteristics in the small-scale model testing.

  3. Comparative Study of Turbines for Wave Energy Conversion

    Institute of Scientific and Technical Information of China (English)

    Hideaki Maeda; Toshiaki Setoguchi; Manabu Takao; Keita Sakurada; Tae-Ho Kin; Kenji Kaneko

    2001-01-01

    The objective of this paper is to compare the performances of the turbines, which could be used for wave energy conversion in the near future, under various irregular wave conditions. The turbines included in the paper are as follows: (a) Wells turbine with guide vanes; (b) impulse turbine with self-pitch-controlled guide vanes; (c) impulse turbine with fixed guide vanes. In this study, experimental investigations were carried out to clarify the performances of the turbines under steady flow conditions, and then a numerical simulation was used for predicting the performances under irregular wave conditions with various significant wave heights. As a result, it was found that the running and starting characteristics of the impulse turbines could be superior to those of the Wells turbine.

  4. Economic and cost engineering aspects of wind energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    MacRae, A.N.

    1990-08-01

    A comprehensive analysis of the economic feasibility of current wind energy conversion systems (WECS) from a cost engineering basis is presented. The initial stage covers a subjective review of the cost implications of various design aspects of current medium sized Horizontal Axis Wind Turbines (HAWTs), based around a 330 kW wind turbine (WT). The second stage is focused on the collection and initial analysis of a comprehensive database of WT technical, cost and performance information from over 100 WT models ranging in size from 8 metre to 55 metre rotor diameter. The formulation of a life cycle cost estimation model for HAWTs, based on semi-empirical relationships between sub-system cost, mass and design parameters is described. The economic feasibility of WECS private generating operation under the tariff structures available in the UK, under the auspices of the Energy Act of 1983, is examined, and broad results are given in terms of feasible tariff scenarios for topographical and regional locations throughout the UK. The prospects for reducing the cost of energy from WECS are explored, and the macro-economic and socio-environmental aspects of WECS are examined. (author).

  5. Analysis of Energy Conversion within a Radial Turbine Stage

    Directory of Open Access Journals (Sweden)

    F. Maroteaux

    2003-03-01

    Full Text Available The results of a detailed study of energy conversion within a radial turbocharger turbine stage are presented in this paper. A 2.5D simulation is conducted near the optimum running point in order to construct the local aero thermodynamic flow field and the associated mechanical energy production within the rotor. Then, a complementary analysis of the flow led within each of the turbine sub-blocks is summarized. The simulation uses models of losses which are studied locally with a multi-dimensional approach and then reduced in 1D description (models reduction allowing establishment of a global turbine performances map. The evaluation of losses appears to be particularly troublesome within such small machines. Losses due to flow-blade profile mismatch which represent a large source of energy dissipation are modeled by way of the entropy balance. The results are compared and validated in accordance with the experiments that were conducted on special turbocharger tests rigs and on a Diesel truck engine test bench.

  6. 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.

  7. 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.

  8. Energy Conversion from Salinity Gradient Using Microchip with Nafion Membrane

    Science.gov (United States)

    Chang, Che-Rong; Yeh, Ching-Hua; Yeh, Hung-Chun; Yang, Ruey-Jen

    2016-06-01

    When a concentrated salt solution and a diluted salt solution are separated by an ion-selective membrane, cations and anions would diffuse at different rates depending on the ion selectivity of the membrane. The difference of positive and negative charges at both ends of the membrane would produce a potential, called the diffusion potential. Thus, electrical energy can be converted from the diffusion potential through reverse electrodialysis. This study demonstrated the fabrication of an energy conversion microchip using the standard micro-electromechanical technique, and utilizing Nafion junction as connecting membrane, which was fabricated by a surface patterned process. Through different salinity gradient of potassium chloride solutions, we experimentally investigated the diffusion potential and power generation from the microchip, and the highest value measured was 135 mV and 339 pW, respectively. Furthermore, when the electrolyte was in pH value of 3.8, 5.6, 10.3, the system exhibited best performance at pH value of 10.3; whereas, pH value of 3.8 yielded the worst.

  9. Intelligent control with implementation on the wind energy conversion system

    International Nuclear Information System (INIS)

    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)

  10. Enhanced photovoltaic energy conversion using thermally based spectral shaping

    Science.gov (United States)

    Bierman, David M.; Lenert, Andrej; Chan, Walker R.; Bhatia, Bikram; Celanović, Ivan; Soljačić, Marin; Wang, Evelyn N.

    2016-06-01

    Solar thermophotovoltaic devices have the potential to enhance the performance of solar energy harvesting by converting broadband sunlight to narrow-band thermal radiation tuned for a photovoltaic cell. A direct comparison of the operation of a photovoltaic with and without a spectral converter is the most critical indicator of the promise of this technology. Here, we demonstrate enhanced device performance through the suppression of 80% of unconvertible photons by pairing a one-dimensional photonic crystal selective emitter with a tandem plasma–interference optical filter. We measured a solar-to-electrical conversion rate of 6.8%, exceeding the performance of the photovoltaic cell alone. The device operates more efficiently while reducing the heat generation rates in the photovoltaic cell by a factor of two at matching output power densities. We determined the theoretical limits, and discuss the implications of surpassing the Shockley–Queisser limit. Improving the performance of an unaltered photovoltaic cell provides an important framework for the design of high-efficiency solar energy converters.

  11. Modeling the Q-cycle mechanism of transmembrane energy conversion

    CERN Document Server

    Smirnov, Anatoly Yu

    2011-01-01

    The Q-cycle mechanism plays an important role in the conversion of the redox energy into the energy of the proton electrochemical gradient across the biomembrane. The bifurcated electron transfer reaction, which is built into this mechanism, recycles one electron, thus, allowing to translocate two protons per one electron moving to the high-potential redox chain. We study a kinetic model of the Q-cycle mechanism in an artificial system which mimics the bf complex of plants and cyanobacteria in the regime of ferredoxin-dependent cyclic electron flow. Using methods of condensed matter physics, we derive a set of master equations and describe a time sequence of electron and proton transfer reactions in the complex. We find energetic conditions when the bifurcation of the electron pathways at the positive side of the membrane occurs naturally, without any additional gates. For reasonable parameter values, we show that this system is able to translocate more than 1.8 protons, on average, per one electron, with a t...

  12. 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.

  13. 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 ...

  14. Symposium on the Physical Chemistry of Solar Energy Conversion, Indianapolis American Chemical Society Meetings, Fall 2013

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Tianquan [PI, Emory Univ.

    2013-09-20

    The Symposium on the Physical Chemistry of Solar Energy Conversion at the Fall ACS Meeting in Indianapolis, IN (Sept. 8-12) featured the following sessions (approx. 6 speakers per session): (1) Quantum Dots and Nanorods for Solar Energy Conversion (2 half-day sessions); (2) Artificial Photosynthesis: Water Oxidation; (3) Artificial Photosynthesis: Solar Fuels (2 half-day sessions); (4) Organic Solar Cells; (5) Novel Concepts for Solar Energy Conversion (2 half-day sessions); (6) Emerging Techniques for Solar Energy Conversion; (7) Interfacial Electron Transfer

  15. 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

  16. 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.

  17. Electric energy by direct conversion from gravitational energy: a gift from superconductivity

    OpenAIRE

    Schilling, Osvaldo F.

    2003-01-01

    We theoretically demonstrate that electromagnetic energy can be obtained by direct, lossless, conversion from gravitational and kinetic energies. For this purpose we discuss the properties of an electromechanical system which consists of a superconducting coil submitted to a constant external force and to magnetic fields. The coil oscillates and has induced in it a rectified electrical current whose magnitude may reach hundreds of Ampere. There is no need for an external electrical power sour...

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

  20. Amphoteric oxide semiconductors for energy conversion devices: a tutorial review.

    Science.gov (United States)

    Singh, Kalpana; Nowotny, Janusz; Thangadurai, Venkataraman

    2013-03-01

    In this tutorial review, we discuss the defect chemistry of selected amphoteric oxide semiconductors in conjunction with their significant impact on the development of renewable and sustainable solid state energy conversion devices. The effect of electronic defect disorders in semiconductors appears to control the overall performance of several solid-state ionic devices that include oxide ion conducting solid oxide fuel cells (O-SOFCs), proton conducting solid oxide fuel cells (H-SOFCs), batteries, solar cells, and chemical (gas) sensors. Thus, the present study aims to assess the advances made in typical n- and p-type metal oxide semiconductors with respect to their use in ionic devices. The present paper briefly outlines the key challenges in the development of n- and p-type materials for various applications and also tries to present the state-of-the-art of defect disorders in technologically related semiconductors such as TiO(2), and perovskite-like and fluorite-type structure metal oxides. PMID:23257778

  1. Challenges of Iran's energy conversion agreements in future competitive market

    International Nuclear Information System (INIS)

    Extensive need for electricity and lack of enough governmental resources for the development of related infrastructures forced the Iranian Government to invite private investors and to sign Energy Conversion Agreement (ECA) in the form of build-operate-transfer (BOT) and build-operate-own (BOO) contracts with them. Accordingly, electricity purchase would be based on a guaranteed price. Changes in some laws in 2007 caused the management of the ECAs and electricity purchase based on guaranteed price to face challenges. Shortening the commercial operation period of the earlier ECAs and signing some new short-term ECAs were the steps taken by the authorities to resolve the problems. By shortening the ECAs' commercial operation period, it is likely to cause serious problems concerning the payments of the project companies, because of shortages in the government's financial resources. The findings of the present viewpoint suggest signing of new long-term contracts (20 years long) in the form of a combinational agreement for buying the produced electricity with a guaranteed price (in the first 5 years) and supplying it in the competitive power market (for the following years) would be a better way to reduce the problems. (author)

  2. 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)

  3. 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.

  4. Overall energy conversion efficiency of a photosynthetic vesicle.

    Science.gov (United States)

    Sener, Melih; Strumpfer, Johan; Singharoy, Abhishek; Hunter, C Neil; Schulten, Klaus

    2016-08-26

    The chromatophore of purple bacteria is an intracellular spherical vesicle that exists in numerous copies in the cell and that efficiently converts sunlight into ATP synthesis, operating typically under low light conditions. Building on an atomic-level structural model of a low-light-adapted chromatophore vesicle from Rhodobacter sphaeroides, we investigate the cooperation between more than a hundred protein complexes in the vesicle. The steady-state ATP production rate as a function of incident light intensity is determined after identifying quinol turnover at the cytochrome bc1 complex (cytb⁢c1) as rate limiting and assuming that the quinone/quinol pool of about 900 molecules acts in a quasi-stationary state. For an illumination condition equivalent to 1% of full sunlight, the vesicle exhibits an ATP production rate of 82 ATP molecules/s. The energy conversion efficiency of ATP synthesis at illuminations corresponding to 1%-5% of full sunlight is calculated to be 0.12-0.04, respectively. The vesicle stoichiometry, evolutionarily adapted to the low light intensities in the habitat of purple bacteria, is suboptimal for steady-state ATP turnover for the benefit of protection against over-illumination.

  5. Lanthanide NIR luminescence for telecommunications, bioanalyses and solar energy conversion

    Institute of Scientific and Technical Information of China (English)

    Jean-Claude; G.; Bünzli; V.

    2010-01-01

    Present-day advanced technologies heavily rely on the exciting magnetic and spectroscopic properties of lanthanide ions. In particular, their ability to generate well-characterized and intense near-infrared (NIR) luminescence is exploited in any modern fiber-optic telecommunication network. In this feature article, we first summarize the whereabouts underlying the design of highly luminescent NIR molecular edifices and materials. We then focus on describing the main trends in three applications related to this spectral range: telecommunications, biosciences, and solar energy conversion. In telecommunications, efforts concentrate presently on getting easily processable polymer-based waveguide amplifiers. Upconversion nanophosphors emitting in the visible after NIR excitation are now ubiquitous in many bioanalyses while their application to bio-imaging is still in its early stages; however, highly sensitive NIR-NIR systems start to be at hand for both in vitro and in vivo imaging, as well as dual probes combining magnetic resonance and optical imaging. Finally, both silicon-based and dye-sensitized solar cells benefit from the downconversion and upconversion capabilities of lanthanide ions to harvest UV and NIR solar light and to boost the overall quantum efficiency of these next-generation devices.

  6. Challenges of Iran's energy conversion agreements in future competitive market

    International Nuclear Information System (INIS)

    Extensive need for electricity and lack of enough governmental resources for the development of related infrastructures forced the Iranian Government to invite private investors and to sign Energy Conversion Agreement (ECA) in the form of build-operate-transfer (BOT) and build-operate-own (BOO) contracts with them. Accordingly, electricity purchase would be based on a guaranteed price. Changes in some laws in 2007 caused the management of the ECAs and electricity purchase based on guaranteed price to face challenges. Shortening the commercial operation period of the earlier ECAs and signing some new short-term ECAs were the steps taken by the authorities to resolve the problems. By shortening the ECAs' commercial operation period, it is likely to cause serious problems concerning the payments of the project companies, because of shortages in the government's financial resources. The findings of the present viewpoint suggest signing of new long-term contracts (20 years long) in the form of a combinational agreement for buying the produced electricity with a guaranteed price (in the first 5 years) and supplying it in the competitive power market (for the following years) would be a better way to reduce the problems

  7. Overall energy conversion efficiency of a photosynthetic vesicle

    Science.gov (United States)

    Sener, Melih; Strumpfer, Johan; Singharoy, Abhishek; Hunter, C Neil; Schulten, Klaus

    2016-01-01

    The chromatophore of purple bacteria is an intracellular spherical vesicle that exists in numerous copies in the cell and that efficiently converts sunlight into ATP synthesis, operating typically under low light conditions. Building on an atomic-level structural model of a low-light-adapted chromatophore vesicle from Rhodobacter sphaeroides, we investigate the cooperation between more than a hundred protein complexes in the vesicle. The steady-state ATP production rate as a function of incident light intensity is determined after identifying quinol turnover at the cytochrome bc1 complex (cytb⁢c1) as rate limiting and assuming that the quinone/quinol pool of about 900 molecules acts in a quasi-stationary state. For an illumination condition equivalent to 1% of full sunlight, the vesicle exhibits an ATP production rate of 82 ATP molecules/s. The energy conversion efficiency of ATP synthesis at illuminations corresponding to 1%–5% of full sunlight is calculated to be 0.12–0.04, respectively. The vesicle stoichiometry, evolutionarily adapted to the low light intensities in the habitat of purple bacteria, is suboptimal for steady-state ATP turnover for the benefit of protection against over-illumination. DOI: http://dx.doi.org/10.7554/eLife.09541.001 PMID:27564854

  8. Conversion of the zero-point energy of the quantum vacuum into classical mechanical energy

    Energy Technology Data Exchange (ETDEWEB)

    Turtur, Claus Wilhelm

    2010-07-01

    A perpetual motion machine - this can never exist. But energy sources nearly disregarded up to now - they exist. These are energy sources, which have been hardly under investigation, so that mankind did not yet learn how to get benefit from them. Most part of the universe consists of such energy, which is still called 'invisible'. A part of this energy is to be found within the so called zero-point oscillations of the quantum vacuum, thus within the empty void from the perspective of quantum physics. The author of the book is physicist. He theoretically developed and then experimentally verified a method for the conversion of vacuum energy into classical mechanical energy. His technique is one of the very few approaches known up to know. The most prominent approaches to convert vacuum energy are described in this book in many scientific details, and they are compared with other known proposals for the use of vacuum energy. (orig.)

  9. Conversion of wind energy. Principios de conversion de la energia eolica

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-01

    This book contains the papers presented at the course ''Conversion of Wind power'' held in CIEMAT. The main sessions were: 1.- Introduction/history 2.- Wind resources 3.- Aerodynamics of wind turbines 4.- Energetic production estimation 5.- Structural analysis 6.- Electric and control systems 7.- Applications 8.- Socioeconomic aspects

  10. Conversion of wind energy; Principios de conversion de la energia eolica

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This book contains the papers presented at the course ``Conversion of Wind power`` held in CIEMAT. The main sessions were: 1.- Introduction/history. 2.- Wind resources. 3.- Aerodynamics of wind turbines. 4.- Structural analysis. 5.- Electric and control systems. 6.- Applications. 7.- Socioeconomic aspects.

  11. Proceedings of the 30. intersociety energy conversion engineering conference. Volume 3

    International Nuclear Information System (INIS)

    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 78 papers in this volume are divided into the following topical sections: (1) Conversion technologies--Heat pumps; Advanced cycles; Thermoelectrics; Thermionics; and AMTEC; (2) Electrochemical conversion--Fuel cells and Batteries for terrestrial applications; (3) New technologies for energy utilization (including Superconductivity); and (4) Stirling cycles and machines--Stirling engine development; Stirling component analysis/testing; Stirling machine simulation and optimization; and Stirling machine analysis. All papers have been processed separately for inclusion on the data base

  12. Thermal underwear. [Energy efficient conversion of Victorian terraced house

    Energy Technology Data Exchange (ETDEWEB)

    Chevin, D.

    1992-01-01

    In a conversion scheme the original masonry will be retained and superinsulated to give a U-value of 0.2 W/m{sup 2}K, and the windows will be insulated with three layers of low-E glass. The building's innards will be ripped out and replaced with a new timber frame of glulam trusses supported by the original loadbearing walls. A distance of 60 cm from the external wall, a new inside skin of semi-translucent panels will be constructed. In cold weather, the panels will remain closed, creating a bank of still air. In warmer weather they can be slid back to increase the living area of each flat. The floor between the two walls on each level is made of glass to increase the daylight within the centre of the building. Sunscoops on the roof level will reflect extra daylight down into the periphery. Energy for space heating and hot water will come from a communal ''solar system'' at the top of the building. On its sloping south side, the timber-framed structure will be fully glazed with glass and polyester sheeting which has reflective louvres sandwiched between those two layers to reduce heat gain during the summer. Heat from rooftop solar collectors is channelled into a communal hot water tank. The flats will be heated by fanning air warmed in the solar attic through a duct down to underfloor vents beneath each dwelling. The attic will be kept hot by using the sun to warm water contained in 250, 14-litre belljars stored there. Filtered air is drawn into the attic, up though vents at the bottom of the south-west facing stairwell and over fragrant plants chosen to absorb organic pollutants. Solar gain from the glazed stairwell warms the air, causing it to rise. Additional energy is saved by extracting heat from this rising fresh air through a heat exchanger. (Author).

  13. Electrolyte- and Transport-Enhanced Thermogalvanic Energy Conversion

    Science.gov (United States)

    Gunawan, Andrey

    Waste heat energy conversion remains an inviting subject for research, given the renewed emphasis on energy efficiency and carbon emissions reduction. Solid-state thermoelectric devices have been widely investigated, but their practical application remains challenging because of cost and the inability to fabricate them in geometries that are easily compatible with heat sources. An intriguing alternative to solid-state thermoelectric devices is thermogalvanic cells, which include a generally liquid electrolyte that permits the transport of ions. Thermogalvanic cells have long been known in the electrochemistry community, but have not received much attention from the thermal transport community. This is surprising given that their performance is highly dependent on controlling both thermal and mass (ionic) transport. This research will focus on a research project, which is an interdisciplinary collaboration between mechanical engineering (i.e. thermal transport) and chemistry, and is a largely experimental effort aimed at improving fundamental understanding of thermogalvanic systems. The first part will discuss how a simple utilization of natural convection within the cell doubles the maximum power output of the cell. In the second part of the research, some of the results from the previous part will be applied in a feasibility study of incorporating thermogalvanic waste heat recovery systems into automobiles. Finally, a new approach to enhance Seebeck coefficient by tuning the configurational entropy of a mixed-ligand complex formation of copper sulfate aqueous electrolytes will be presented. Ultimately, a summary of these results as well as possible future work that can be formed from these efforts is discussed.

  14. 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

  15. Embedded SMA wire actuated biomimetic fin: a module for biomimetic underwater propulsion

    Science.gov (United States)

    Wang, Zhenlong; Hang, Guanrong; Wang, Yangwei; Li, Jian; Du, Wei

    2008-04-01

    An embedded shape memory alloy (SMA) wire actuated biomimetic fin is presented, and based on this module for biomimetic underwater propulsion, a micro robot fish (146 mm in length, 30 g in weight) and a robot squid (242 mm in length, 360 g in weight) were developed. Fish swim by undulating their body and/or fins. Squid and cuttlefish can also swim by undulating their fins. To simplify engineering modeling, the undulating swimming movement is assumed to be the integration of the movements of many flexible bending segments connected in parallel or in series. According to this idea, a biomimetic fin which can bend flexibly was developed. The musculature of a cuttlefish fin was investigated to aid the design of the biomimetic fin. SMA wires act as 'muscle fibers' to drive the biomimetic fin just like the transverse muscles of the cuttlefish fin. During the bending phase, elastic energy is stored in the elastic substrate and skin, and during the return phase, elastic energy is released to power the return movement. Theorem analysis of the bending angle was performed to estimate the bending performance of the biomimetic fin. Experiments were carried out on single-face fins with latex rubber skin and silicone skin (SF-L and SF-S) to compare the bending angle, return time, elastic energy storage and reliability. Silicone was found to be the better skin. A dual-face fin with silicone skin (DF-S) was tested in water to evaluate the actuating performance and to validate the reliability. Thermal analysis of the SMA temperature was performed to aid the control strategy. The micro robot fish and robot squid employ one and ten DF-S, respectively. Swimming experiments with different actuation frequencies were carried out. The speed and steering radius of the micro robot fish reached 112 mm s-1 and 136 mm, respectively, and the speed and rotary speed of the robot squid reached 40 mm s-1 and 22° s-1, respectively.

  16. Embedded SMA wire actuated biomimetic fin: a module for biomimetic underwater propulsion

    International Nuclear Information System (INIS)

    An embedded shape memory alloy (SMA) wire actuated biomimetic fin is presented, and based on this module for biomimetic underwater propulsion, a micro robot fish (146 mm in length, 30 g in weight) and a robot squid (242 mm in length, 360 g in weight) were developed. Fish swim by undulating their body and/or fins. Squid and cuttlefish can also swim by undulating their fins. To simplify engineering modeling, the undulating swimming movement is assumed to be the integration of the movements of many flexible bending segments connected in parallel or in series. According to this idea, a biomimetic fin which can bend flexibly was developed. The musculature of a cuttlefish fin was investigated to aid the design of the biomimetic fin. SMA wires act as 'muscle fibers' to drive the biomimetic fin just like the transverse muscles of the cuttlefish fin. During the bending phase, elastic energy is stored in the elastic substrate and skin, and during the return phase, elastic energy is released to power the return movement. Theorem analysis of the bending angle was performed to estimate the bending performance of the biomimetic fin. Experiments were carried out on single-face fins with latex rubber skin and silicone skin (SF-L and SF-S) to compare the bending angle, return time, elastic energy storage and reliability. Silicone was found to be the better skin. A dual-face fin with silicone skin (DF-S) was tested in water to evaluate the actuating performance and to validate the reliability. Thermal analysis of the SMA temperature was performed to aid the control strategy. The micro robot fish and robot squid employ one and ten DF-S, respectively. Swimming experiments with different actuation frequencies were carried out. The speed and steering radius of the micro robot fish reached 112 mm s−1 and 136 mm, respectively, and the speed and rotary speed of the robot squid reached 40 mm s−1 and 22° s−1, respectively

  17. Scaling laws of energy conversion and neutron yield for imploding targets driven by radiation

    International Nuclear Information System (INIS)

    Imploding targets driven by radiation are analyzed theoretically. Energy conversion relations with uncertain parameters are obtained. Based on numerical simulation for the physical model, the uncertain parameters stated above are determined, and both the scaling lows of energy conversion and neutron yield are given

  18. Discovering Inexpensive, Effective Catalysts for Solar Energy Conversion: An Authentic Research Laboratory Experience

    Science.gov (United States)

    Shaner, Sarah E.; Hooker, Paul D.; Nickel, Anne-Marie; Leichtfuss, Amanda R.; Adams, Carissa S.; de la Cerda, Dionisia; She, Yuqi; Gerken, James B.; Pokhrel, Ravi; Ambrose, Nicholas J.; Khaliqi, David; Stahl, Shannon S.; Schuttlefield Christus, Jennifer D.

    2016-01-01

    Electrochemical water oxidation is a major focus of solar energy conversion efforts. A new laboratory experiment has been developed that utilizes real-time, hands-on research to discover catalysts for solar energy conversion. The HARPOON, or Heterogeneous Anodes Rapidly Perused for Oxygen Overpotential Neutralization, experiment allows an array of…

  19. Efficiency of a gyroscopic device for conversion of mechanical wave energy to electrical energy

    DEFF Research Database (Denmark)

    Carlsen, Martin; Darula, Radoslav; Gravesen, Jens;

    2011-01-01

    We consider a recently proposed gyroscopic device for conversion of mechanical ocean wave energy to electrical energy. Two models of the device derived from standard engineering mechanics from the literature are analysed, and a model is derived from analytical mechanics considerations. From...... these models, estimates of the power production, eciency, forces and moments are made. We nd that it is possible to extract a signicant amount of energy from an ocean wave using the described device. Further studies are required for a full treatment of the device....

  20. Method of Measuring the Efficiency of the Conversion of Nuclear Energy into Optical Energy

    Directory of Open Access Journals (Sweden)

    Erlan G. Batyrbekov

    2015-01-01

    Full Text Available A method of measuring the efficiency of converting nuclear energy into optical energy was developed based on correlations between intensities of the research line and the nitrogen second positive system in an Ar-N2 mixture. In addition, the values of the coefficient of the conversion of nuclear energy into radiation at the lines of a Hg triplet in mixtures of Хе-Hg and Kr-Hg were determined. The values measured correspond to a selectiveness of pumping of 73S1 that was close to 1 (δ=0.8±0.2.

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

    OpenAIRE

    Lowe, R J

    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 ener...

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-09-01

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

  4. Biomimetics materials, structures and processes : examples, ideas and case studies

    CERN Document Server

    Bruckner, Dietmar; Hellmich, Christian; Schmiedmayer, Heinz-Bodo; Stachelberger, Herbert; Gebeshuber, Ille

    2011-01-01

    The book presents an outline of current activities in the field of biomimetics and integrates a variety of applications comprising biophysics, surface sciences, architecture and medicine. Biomimetics as innovation method is characterised by interdisciplinary information transfer from the life sciences to technical application fields aiming at increased performance, functionality and energy efficiency. The contributions of the book relate to the research areas: - Materials and structures in nanotechnology and biomaterials - Biomimetic approaches to develop new forms, construction principles and design methods in architecture - Information and dynamics in automation, neuroinformatics and biomechanics Readers will be informed about the latest research approaches and results in biomimetics with examples ranging from bionic nano-membranes to function-targeted design of tribological surfaces and the translation of natural auditory coding strategies.

  5. The research on direct-drive wave energy conversion system and performance optimization

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhongxian; YU Haitao; HU Minqiang

    2014-01-01

    A direct-drive wave energy conversion system based on a three-phase permanent magnet tubular linear generator (PMTLG) and a heaving buoy is proposed to convert wave energy into electrical energy. Sufficient experimental methods are adopted to compare the computer simulations, the validity of which is verified by the experiment results from a wave tank laboratory. In the experiment, the motion curves of heaving buoy are with small fluctuations, mainly caused by the PMTLG’s detent force. For the reduction of these small fluctuations and a maximum operational efficiency of the direct-drive wave energy conversion system, the PMTLG’s detent force minimization technique and the heaving buoy optimization will be discussed. It is discovered that the operational efficiency of the direct-drive wave energy conversion system increases dra-matically after optimization. The experiment and optimization results will provide useful reference for the future research on ocean wave energy conversion system.

  6. 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

  7. Biomimetic sensor design

    Science.gov (United States)

    Lee, Ju Hun; Jin, Hyo-Eon; Desai, Malav S.; Ren, Shuo; Kim, Soyoun; Lee, Seung-Wuk

    2015-11-01

    Detection of desired target chemicals in a sensitive and selective manner is critically important to protect human health, environment and national security. Nature has been a great source of inspiration for the design of sensitive and selective sensors. In this mini-review, we overview the recent developments in bio-inspired sensor development. There are four major components of sensor design: design of receptors for specific targets; coating materials to integrate receptors to transducing machinery; sensitive transducing of signals; and decision making based on the sensing results. We discuss the biomimetic methods to discover specific receptors followed by a discussion about bio-inspired nanocoating material design. We then review the recent developments in phage-based bioinspired transducing systems followed by a discussion of biomimetic pattern recognition-based decision making systems. Our review will be helpful to understand recent approaches to reverse-engineer natural systems to design specific and sensitive sensors.

  8. PEM Fuel Cells Redesign Using Biomimetic and TRIZ Design Methodologies

    Science.gov (United States)

    Fung, Keith Kin Kei

    Two formal design methodologies, biomimetic design and the Theory of Inventive Problem Solving, TRIZ, were applied to the redesign of a Proton Exchange Membrane (PEM) fuel cell. Proof of concept prototyping was performed on two of the concepts for water management. The liquid water collection with strategically placed wicks concept demonstrated the potential benefits for a fuel cell. Conversely, the periodic flow direction reversal concepts might cause a potential reduction water removal from a fuel cell. The causes of this water removal reduction remain unclear. In additional, three of the concepts generated with biomimetic design were further studied and demonstrated to stimulate more creative ideas in the thermal and water management of fuel cells. The biomimetic design and the TRIZ methodologies were successfully applied to fuel cells and provided different perspectives to the redesign of fuel cells. The methodologies should continue to be used to improve fuel cells.

  9. Biomimetic hydrogel materials

    Science.gov (United States)

    Bertozzi, Carolyn; Mukkamala, Ravindranath; Chen, Qing; Hu, Hopin; Baude, Dominique

    2000-01-01

    Novel biomimetic hydrogel materials and methods for their preparation. Hydrogels containing acrylamide-functionalized carbohydrate, sulfoxide, sulfide or sulfone copolymerized with a hydrophilic or hydrophobic copolymerizing material selected from the group consisting of an acrylamide, methacrylamide, acrylate, methacrylate, vinyl and a derivative thereof present in concentration from about 1 to about 99 wt %. and methods for their preparation. The method of use of the new hydrogels for fabrication of soft contact lenses and biomedical implants.

  10. Design, Construction and Ocean Testing of Wave Energy Conversion System with Permanent Magnet Tubular Linear Generator

    Institute of Scientific and Technical Information of China (English)

    陈中显; 余海涛; 刘春元; 洪立玮

    2016-01-01

    In this paper, the design, construction and ocean testing of a wave energy conversion system are stud-ied. Based on the motion characteristics of double buoys in ocean waves, a wave energy conversion system with permanent magnet tubular linear generator(PMTLG)is proposed to convert ocean wave energy into electricity. The wave energy conversion system was installed in the Yellow Sea near Lianyungang, China. The ocean test re-sults indicate that it had dynamic and static performance, and obtained an expected amount of electricity. The calcu-lation result indicates the average output power was about 1,000,W, and the conversion efficiency from wave en-ergy into electricity was 1.4%,. In addition, the wireless data communication, mechanics and oceanography were also discussed.

  11. Solution-Processed Two-Dimensional Metal Dichalcogenide-Based Nanomaterials for Energy Storage and Conversion.

    Science.gov (United States)

    Cao, Xiehong; Tan, Chaoliang; Zhang, Xiao; Zhao, Wei; Zhang, Hua

    2016-08-01

    The development of renewable energy storage and conversion devices is one of the most promising ways to address the current energy crisis, along with the global environmental concern. The exploration of suitable active materials is the key factor for the construction of highly efficient, highly stable, low-cost and environmentally friendly energy storage and conversion devices. The ability to prepare two-dimensional (2D) metal dichalcogenide (MDC) nanosheets and their functional composites in high yield and large scale via various solution-based methods in recent years has inspired great research interests in their utilization for renewable energy storage and conversion applications. Here, we will summarize the recent advances of solution-processed 2D MDCs and their hybrid nanomaterials for energy storage and conversion applications, including rechargeable batteries, supercapacitors, electrocatalytic hydrogen generation and solar cells. Moreover, based on the current progress, we will also give some personal insights on the existing challenges and future research directions in this promising field.

  12. Modelling and Control of Tidal Energy Conversion Systems with Long Distance Converters

    OpenAIRE

    Sousounis, Marios; Shek, Jonathan; Mueller, Markus

    2014-01-01

    In order to optimise a tidal energy conversion system operation, maintenance and power generation aspects have to be taken into account. As a result the key focus of this paper is to propose and investigate an alternative method of implementing a tidal energy conversion system using a pitch-regulated turbine and a variable-speed squirrel cage induction generator with long distance converters. The generator power output can be optimised by utilising variable-speed control strategies allowing t...

  13. DOE-EFRC Center on Nanostructuring for Efficient Energy Conversion (CNEEC)

    Energy Technology Data Exchange (ETDEWEB)

    Prinz, Friedrich B. [Stanford Univ., CA (United States). Mechanical Engineering. Materials Science and Engineering; Bent, Stacey F. [Stanford Univ., CA (United States). Chemical Engineering

    2015-10-22

    CNEEC’s mission has been to understand how nanostructuring of materials can enhance efficiency for solar energy conversion to produce hydrogen fuel and to solve fundamental cross-cutting problems. The overarching hypothesis underlying CNEEC research was that controlling, synthesizing and modifying materials at the nanometer scale increases the efficiency of energy conversion and storage devices and systems. In this pursuit, we emphasized the development of functional nanostructures that are based primarily on earth abundant and inexpensive materials.

  14. Analysis on Energy Conversion of Screw Centrifugal Pump in Impeller Domain Based on Profile Lines

    OpenAIRE

    Hui Quan; Rennian Li; Qingmiao Su; Wei Han; Pengcheng Wang

    2013-01-01

    In order to study the power capability of impeller and energy conversion mechanism of screw centrifugal pump, the methods of theoretical analysis and numerical simulation by computational fluid dynamics theory (CFD) were adopted, specifically discussing the conditions of internal flow such as velocity, pressure, and concentration. When the medium is sand-water two-phase flow and dividing the rim of the lines and wheel lines of screw centrifugal pump to segments to analyze energy conversion ca...

  15. EnerGis: A geographical information based system for the evaluation of integrated energy conversion systems in urban areas

    Energy Technology Data Exchange (ETDEWEB)

    Girardin, Luc; Marechal, Francois; Dubuis, Matthias; Calame-Darbellay, Nicole; Favrat, Daniel [Ecole Polytechnique Federale de Lausanne, LENI-IGE-STI, Bat. ME A2, Station 9, 1015 Lausanne (Switzerland)

    2010-02-15

    A geographical information system has been developed to model the energy requirements of an urban area. The purpose of the platform is to model with sufficient detail the energy services requirements of a given geographical area in order to allow the evaluation of the integration of advanced integrated energy conversion systems. This tool is used to study the emergence of more efficient cities that realize energy efficiency measures, integrate energy efficient conversion technologies and promote the use of endogenous renewable energy. The model is illustrated with case studies for the energetic planning of the Geneva district (Switzerland). (author)

  16. Coulomb explosion of nanodroplets drives the conversion of laser energy to nuclear energy

    Institute of Scientific and Technical Information of China (English)

    Isidore; Last; Shlomo; Ron; Andreas; Heidenreich; Joshua; Jortner

    2013-01-01

    Theoretical–computational studies of table-top laser-driven nuclear fusion of high-energy(up to 15 MeV)deuterons with7Li,6Li,and D nuclei demonstrate the attainment of high fusion yields within a source–target reaction design.This constitutes a source of Coulomb-exploding deuterium nanodroplets driven by an ultraintense femtosecond near-infrared laser and a solid hollow cylindrical target containing the second element.The source–target reaction design attains the highest table-top fusion efficiencies(up to 4×109J 1per laser pulse)obtained to date.The highest conversion efficiency of laser energy to nuclear energy(10 2–10 3)for table-top DD fusion attained in the source–target design is comparable to that for DT fusion currently accomplished for‘big science’inertial fusion setups.

  17. Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 2: Advanced energy conversion systems. Part 1: Open-cycle gas turbines

    Science.gov (United States)

    Brown, D. H.; Corman, J. C.

    1976-01-01

    Ten energy conversion systems are defined and analyzed in terms of efficiency. These include: open-cycle gas turbine recuperative; open-cycle gas turbine; closed-cycle gas turbine; supercritical CO2 cycle; advanced steam cycle; liquid metal topping cycle; open-cycle MHD; closed-cycle inert gas MHD; closed-cycle liquid metal MHD; and fuel cells. Results are presented.

  18. Design of high energy density thermoelectric energy conversion unit by using FGM compliant pads

    CERN Document Server

    Kambe, M

    1999-01-01

    In order to provide increasingly large amounts of electrical power to space and terrestrial systems with a sufficiently high level of reliability at a reasonable cost, thermoelectric (TE) energy conversion system by using $9 functionally graded material (FGM) compliant pads has been focused. To achieve high thermal energy density in TE power conversion systems, conductively coupling the TE units to the hot and cold heat exchangers is the most effective $9 configuration. This is accomplished by two sets of FGM compliant pads. This design strategy provides (1) a high flux, direct conduction path to heat source and heat sink, (2) the structural flexibility to protect the cell from high $9 stress due to thermal expansion, (3) an extended durability by a simple FGM structure, and (4) manufacturing cost reduction by spark plasma sintering. High thermal energy density of ten times as much as conventional radioisotope $9 thermoelectric generator is expected. Manufacturing of Cu/Al/sub 2/O/sub 3//Cu symmetrical FGM co...

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

    Science.gov (United States)

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

    2016-07-01

    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.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

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

    International Nuclear Information System (INIS)

    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

  1. EXAMINING A SERIES RESONANT INVERTER CIRCUIT TO USE IN THE PHOTOVOLTAIC ENERGY CONVERSION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Engin ÇETİN

    2004-03-01

    Full Text Available As we know, solar energy is the energy source which is environment friendly, renewable, and can be found easily. Particularly, in the recent years, interest on producing electrical energy by alternative energy sources increased because of the fact that underground sources are not enough to produce energy in the future and also these sources cause enviromental pollution. The solar energy is one of the most popular one among the alternative energy sources. Photovoltaic systems produce the electrical energy from the sunlight. In this study, a series resonant inverter circuit which is used in the photovoltaic energy conversion systems has been examined.Effects of the series resonant inverter circuit on the photovoltaic energy conversion system have been investigated and examined

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

    Science.gov (United States)

    Finke, R. C.

    1982-01-01

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

  3. Biomimetic magnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Michael T. Klem

    2005-09-01

    Full Text Available Magnetic nanoparticles are of considerable interest because of their potential use in high-density memory devices, spintronics, and applications in diagnostic medicine. The conditions for synthesis of these materials are often complicated by their high reaction temperatures, costly reagents, and post-processing requirements. Practical applications of magnetic nanoparticles will require the development of alternate synthetic strategies that can overcome these impediments. Biomimetic approaches to materials chemistry have provided a new avenue for the synthesis and assembly of magnetic nanomaterials that has great potential for overcoming these obstacles.

  4. Solar energy conversion via hot electron internal photoemission in metallic nanostructures: Efficiency estimates

    International Nuclear Information System (INIS)

    Collection of hot electrons generated by the efficient absorption of light in metallic nanostructures, in contact with semiconductor substrates can provide a basis for the construction of solar energy-conversion devices. Herein, we evaluate theoretically the energy-conversion efficiency of systems that rely on internal photoemission processes at metal-semiconductor Schottky-barrier diodes. In this theory, the current-voltage characteristics are given by the internal photoemission yield as well as by the thermionic dark current over a varied-energy barrier height. The Fowler model, in all cases, predicts solar energy-conversion efficiencies of <1% for such systems. However, relaxation of the assumptions regarding constraints on the escape cone and momentum conservation at the interface yields solar energy-conversion efficiencies as high as 1%–10%, under some assumed (albeit optimistic) operating conditions. Under these conditions, the energy-conversion efficiency is mainly limited by the thermionic dark current, the distribution of hot electron energies, and hot-electron momentum considerations

  5. 20th intersociety energy conversion engineering conference. Volume 2

    International Nuclear Information System (INIS)

    This volume contains information on the mission and status of the DOE's battery energy storage program, the development of an advanced battery electric energy storage system for electric utility load leveling, and the aluminum-air power cell. Plastic-bonded, nonsintered nickel-cadmium batteries for submarines and the cycle life chemistry of ambient-temperature secondary lithium cells are also discussed. The development of zinc-bromine batteries for stationary energy storage, the development of a zinc-chloride battery for 10-kw electric energy storage, and sodium sulfur cells with high conductivity glass electrolytes are discussed. The recovery of lead/acid batteries from abusive deep discharge, and high rate lithium batteries safety testing for U.L. component recognition are reviewed. Enhanced energy recovery, geothermal power, and heat engine cycles are discussed. Hydrogen energy, magnetohydrodynamics and nuclear fission are examined

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

    Science.gov (United States)

    Parlevliet, David; Moheimani, Navid Reza

    2014-01-01

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

  7. Innovative rubble mound breakwaters for overtopping wave energy conversion

    DEFF Research Database (Denmark)

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

    2014-01-01

    This paper intends contributing to the development of an economically and environmentally sustainable coastal infrastructure, which combines rubble mound breakwaters with Wave Energy Converters (WEC). The energy is produced by collecting wave overtopping in a front reservoir, which is returned...... experiments. The formulae are provided with the aim to be of direct use to engineers in the preliminary design of a first prototype of combined breakwater and wave energy converter....

  8. A new solid-conversion gas detector for high energy X-ray industrial computed tomography

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ri-feng; CHEN Wei-min; DUAN Xiao-jiao

    2011-01-01

    A new type of solid-conversion gas detector is investigated for high energy X-ray industrial computed tomography(H ECT).The conversion efficiency is calculated by using the EGSnrc Monte Carlo code on the Linux platform to simulate the transport process of photons and electrons in the detector.The simulation results show that the conversion efficiency could be more than 65%,if the X-ray beam width is less than about 0.2 mm,and a tungsten slab with 0.2 mum thickness and 30 mm length is employed as a radiation conversion medium.Meanwhile the results indicate that this new detector has higher conversion efficiency as well as less volume.Theoretically this new kind of detector could take place of the traditional scintillation detector for HECT.

  9. Evaluation of Various Technologies for Wave Energy Conversion in the Portuguese Nearshore

    Directory of Open Access Journals (Sweden)

    Carlos Guedes Soares

    2013-03-01

    Full Text Available The objective of the present work is to perform an evaluation of the performance provided by various technologies for wave energy conversion in the Portuguese continental coastal environment. The wave climate in the target area is first analyzed using the results from three years of simulations with a wave prediction system based on numerical models. Based on the above data, diagrams for the bivariate distributions of the sea states occurrences, defined by the significant wave height and the energy period, are designed for both winters and whole years. On this basis, the output of five different technologies for the conversion of wave energy is assessed in some relevant locations from the Portuguese nearshore. According to the results obtained, the Portuguese continental coastal environment appears to be appropriate for the wave energy extraction. At the same time, the present work shows that the output of the wave energy conversion devices does not depend only on the average wave energy but is also dependent on the distribution of the wave energy among the sea states of different periods. For this reason, a good agreement between the characteristics of the power matrices of the wave energy converters operating in a certain place and the diagrams for the bivariate distributions of the sea states occurrences corresponding to the considered location represents a key issue in selecting the most appropriate technology for wave energy conversion.

  10. 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.

  11. 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.

  12. 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. PMID:27430282

  13. Biomimetics in Tribology

    Science.gov (United States)

    Gebeshuber, I. C.; Majlis, B. Y.; Stachelberger, H.

    Science currently goes through a major change. Biology is evolving as new Leitwissenschaft, with more and more causation and natural laws being uncovered. The term `technoscience' denotes the field where science and technology are inseparably interconnected, the trend goes from papers to patents, and the scientific `search for truth' is increasingly replaced by search for applications with a potential economic value. Biomimetics, i.e. knowledge transfer from biology to technology, is a field that has the potential to drive major technical advances. The biomimetic approach might change the research landscape and the engineering culture dramatically, by the blending of disciplines. It might substantially support successful mastering of current tribological challenges: friction, adhesion, lubrication and wear in devices and systems from the meter to the nanometer scale. A highly successful method in biomimectics, the biomimicry innovation method, is applied in this chapter to identify nature's best practices regarding two key issues in tribology: maintenance of the physical integrity of a system, and permanent as well as temporary attachment. The best practices identified comprise highly diverse organisms and processes and are presented in a number of tables with detailed references.

  14. Legal-institutional arrangements facilitating offshore wind energy conversion systems (WECS) utilization. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mayo, L.H.

    1977-09-01

    Concern for the continuing sufficiency of energy supplies in the U.S. has tended to direct increasing attention to unconventional sources of supply, including wind energy. Some of the more striking proposals for the utilization of wind energy relate to offshore configurations. The legal-institutional arrangements for facilitating the utilization of offshore wind energy conversion systems (WECS) are examined by positioning three program alternatives and analyzing the institutional support required for the implementation of each.

  15. Effect of biomass feedstock chemical and physical properties on energy conversion processes: Volume 2, Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Butner, R.S.; Elliott, D.C.; Sealock, L.J., Jr.; Pyne, J.W.

    1988-12-01

    This report presents an exploration of the relationships between biomass feedstocks and the conversion processes that utilize them. Specifically, it discusses the effect of the physical and chemical structure of biomass on conversion yields, rates, and efficiencies in a wide variety of available or experimental conversion processes. A greater understanding of the complex relationships between these conversion systems and the production of biomass for energy uses is required to help optimize the complex network of biomass production, collection, transportation, and conversion to useful energy products. The review of the literature confirmed the scarcity of research aimed specifically at identifying the effect of feedstock properties on conversion. In most cases, any mention of feedstock-related effects was limited to a few brief remarks (usually in qualitative terms) in the conclusions, or as a topic for further research. Attempts to determine the importance of feedstock parameters from published data were further hampered by the lack of consistent feedstock characterization and the difficulty of comparing results between different experimental systems. Further research will be required to establish quantitative relationships between feedstocks and performance criteria in conversion. 127 refs., 4 figs., 7 tabs.

  16. Thermoelectric Oxide Modules (TOMs) for the Direct Conversion of Simulated Solar Radiation into Electrical Energy

    OpenAIRE

    Petr Tomeš; Matthias Trottmann; Clemens Suter; Myriam Heidi Aguirre; Aldo Steinfeld; Philipp Haueter; Anke Weidenkaff

    2010-01-01

    The direct conversion of concentrated high temperature solar heat into electrical energy was demonstrated with a series of four–leg thermoelectric oxide modules (TOM). These temperature stable modules were not yet optimized for high efficiency conversion, but served as proof-of-principle for high temperature conversion. They were constructed by connecting two p- (La1.98Sr0.02CuO4) and two n-type (CaMn0.98Nb0.02O3) thermoelements electrically in series and thermally in parallel. The temperatur...

  17. Potential environmental consequences of ocean thermal energy conversion (OTEC) plants. A workshop

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, J.J. (ed.)

    1981-05-01

    The concept of generating electrical power from the temperature difference between surface and deep ocean waters was advanced over a century ago. A pilot plant was constructed in the Caribbean during the 1920's but commercialization did not follow. The US Department of Energy (DOE) earlier planned to construct a single operational 10MWe Ocean Thermal Energy Conversion (OTEC) plant by 1986. However, Public Law P.L.-96-310, the Ocean Thermal Energy Conversion Research, Development and Demonstration Act, and P.L.-96-320, the Ocean Thermal Energy Conversion Act of 1980, now call for acceleration of the development of OTEC plants, with capacities of 100 MWe in 1986, 500 MWe in 1989, and 10,000 MWe by 1999 and provide for licensing and permitting and loan guarantees after the technology has been demonstrated.

  18. A universal, broad-environment energy conversion signature of explosive cyclones

    Science.gov (United States)

    Black, Mitchell Timothy; Pezza, Alexandre Bernardes

    2013-01-01

    This study presents the first analysis of the Lorenz energetics associated with a global climatology of explosive cyclones. Energy budgets of the large-scale environment are calculated for 32 year climatologies (1980-2011) of explosive cyclones within four of the most active regions in the world: the Northwest Pacific, the North Atlantic, the Southwest Pacific, and the South Atlantic. A robust signature in the Lorenz energy cycle is observed; anomalous energy conversions commence 48 h before explosive cyclone development and remain strong (i.e., significantly above background noise) for 120 h. Remarkably, the calculated signature of energy conversion is virtually identical for all four geographical regions. While the conversions imply a classic baroclinic growth cycle, they are not seen in regular cyclones that undergo a deepening of less than half that exhibited by explosive cyclones. This finding opens a new avenue of exploration of explosive storm behavior based on the large-scale environment.

  19. Biomimetic Cilia Based on MEMS Technology

    Institute of Scientific and Technical Information of China (English)

    Zhi-guo Zhou; Zhi-wen Liu

    2008-01-01

    A review on the research of Micro Electromechanical Systems (MEMS) technology based biomimetic cilia is presented. Biomimetic cilia, enabled by the advancement of MEMS technology, have been under dynamic development for the past decade. After a brief description of the background of cilia and MEMS technology, different biomimetic cilia applications are reviewed. Biomimetic cilia micro-actuators, including micromachined polyimide bimorph biomimetic cilia micro-actuator, electro-statically actuated polymer biomimetic cilia micro-actuator, and magnetically actuated nanorod array biomimetic cilia micro-actuator, are presented. Subsequently micromachined underwater flow biomimetic cilia micro-sensor is studied, followed by acoustic flow micro-sensor. The fabrication of these MEMS-based biomimetic cilia devices, characterization of their physical properties, and the results of their application experiments are discussed.

  20. Conversion of Solar Energy to Fuels by Inorganic Heterogeneous Systems

    Institute of Scientific and Technical Information of China (English)

    Kimfung LI; David MARTIN; Junwang TANG

    2011-01-01

    Over the last several years, the need to find clean and renewable energy sources has increased rapidly because current fossil fuels will not only eventually be depleted, but their continuous combustion leads to a dramatic increase in the carbon dioxide amount in atmosphere. Utilisation of the Sun's radiation can provide a solution to both problems. Hydrogen fuel can be generated by using solar energy to split water, and liquid fuels can be produced via direct CO2 photoreduction. This would create an essentially free carbon or at least carbon neutral energy cycle. In this tutorial review, the current progress in fuels' generation directly driven by solar energy is summarised. Fundamental mechanisms are discussed with suggestions for future research.

  1. Energy Transfer and Conversion in the Magnetosphere-Ionosphere System

    OpenAIRE

    Rosenqvist, Lisa

    2008-01-01

    Magnetized planets, such as Earth, are strongly influenced by the solar wind. The Sun is very dynamic, releasing varying amounts of energy, resulting in a fluctuating energy and momentum exchange between the solar wind and planetary magnetospheres. The efficiency of this coupling is thought to be controlled by magnetic reconnection occurring at the boundary between solar wind and planetary magnetic fields. One of the main tasks in space physics research is to increase the understanding of thi...

  2. Light-harvesting materials: Soft support for energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Stolley, Ryan M.; Helm, Monte L.

    2014-11-10

    To convert solar energy into viable fuel sources, coupling light-harvesting materials to catalysts is a critical challenge. Now, coupling between an organic supramolecular hydrogel and a non precious metal catalyst has been demonstrated to be effective for photocatalytic H2 production. Ryan M. Stolley and Monte L. Helm are at Pacific Northwest National Laboratory (PNNL), Richland, WA, USA 99352. PNNL is operated by Battelle for the US Department of Energy. e-mail: Monte.Helm@pnnl.gov

  3. Energy Conversion Analysis of a Novel Solar Thermochemical System Coupled with Fuel Cells

    OpenAIRE

    Vinck, Ian; Ozalp, Nesrin

    2015-01-01

    Fossil fuels have been the main supply of power generation for use in manufacturing, transportation, residential and commercial sectors. However, environmentally adverse effects of fossil fuel conversion systems combined with pending shortage raise major concerns. As a promising approach to tackle these challenges, this paper presents a novel energy conversion system comprising of a solar thermal reactor coupled with hydrogen fuel cell and carbon fuel cell for electricity generation. The syst...

  4. Evaluation of fluence to dose equivalent conversion factors for high energy radiations, (1)

    International Nuclear Information System (INIS)

    Computer code system and basic data have been investigated for evaluating fluence to dose equivalent conversion factors for photons and neutrons up to 10 GeV. The present work suggested that the conversion factors would be obtained by incorporating effective quality factors of charged particles into the HERMES (High Energy Radiation Monte Carlo Elaborate System) code system. The effective quality factors for charged particles were calculated on the basis of the Q-L relationships specified in the ICRP Publication-60. (author)

  5. Transition metal based layered double hydroxides tailored for energy conversion and storage

    OpenAIRE

    Xia Long; Zilong Wang; Shuang Xiao; Yiming An; Shihe Yang

    2016-01-01

    Layered double hydroxides (LDHs) are a class of clays with brucite like layers and intercalated anions. The first (3d) series transition metals based LDHs (TM-LDHs) are attracting increasing interest in the field of energy conversion and storage processes due to their unique physicochemical properties. In this article, we review recent developments in the synthesis and applications of TM-LDH in these areas including water splitting, CO2 conversion, metal-air batteries and supercapacitors and ...

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

    International Nuclear Information System (INIS)

    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

  7. Fundamental Principle of Information-to-Energy Conversion

    CERN Document Server

    Alfonso-Faus, Antonio

    2014-01-01

    The equivalence of 1 bit of information to entropy was given by Landauer in 1961 as kln2, k the Boltzmann constant. Erasing information implies heat dissipation and the energy of 1 bit would then be (the Landauers limit) kT ln 2, T being the ambient temperature. From a quantum-cosmological point of view the minimum quantum of energy in the universe corresponds today to a temperature of 10^(-29) degrees K, probably forming a cosmic background of a Bose condensate [1]. Then, the bit with minimum energy today in the Universe is a quantum of energy 10^(-45)ergs, with an equivalent mass of 10^(-66)g. Low temperature implies low energy per bit and, of course, this is the way for faster and less energy dissipating computing devices. Our conjecture is this: the possibility of a future access to the CBBC (a coupling/channeling?) would mean a huge jump in the performance of these devices.

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

    Science.gov (United States)

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

    2013-01-01

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

  9. Dynamic modelling and robust control of a wind energy conversion system

    NARCIS (Netherlands)

    Steinbuch, M.

    1989-01-01

    The application of wind energy conversion systems for the production of electrical energy requires a cheap and reliable operation. Especially at high wind velocities fluctuations from the wind field result in large mechanical loads of the wind turbine. Also fluctuations in the grid voltage may yield

  10. Simulating the physiology of athletes during endurance sports events: Modelling human energy conversion and metabolism

    NARCIS (Netherlands)

    Beek, J.H.G.M. van; Supandi, F.; Gavai, A.K.; Graaf, A.A. de; Binsl, T.W.; Hettling, H.

    2011-01-01

    The human physiological system is stressed to its limits during endurance sports competition events.We describe a whole body computational model for energy conversion during bicycle racing. About 23 per cent of the metabolic energy is used for muscle work, the rest is converted to heat. We calculate

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

    International Nuclear Information System (INIS)

    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

  12. Assessment of dynamic energy conversion systems for radioisotope heat sources

    International Nuclear Information System (INIS)

    The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were Stirling; Brayton Cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos Multiattribute Decision Theory code. Three different heat source designs were used: case I with a beginning of life (BOL) source temperature of 640 C, case II with a BOL source temperature of 7450C, and case III with a BOL source temperature of 9450C. The Stirling engine system was the top-ranked system of cases I and II, closely followed by the ORC systems in case I and ORC plus thermoelectrics in case II. The Brayton cycle system was top-ranked for case III, with the Stirling engine system a close second. The use of 238Pu in heat source sizes of 7500 W(t) was examined and found to be questionable because of cost and material availability and because of additional requirements for analysis of safeguards and critical mass

  13. Study of a wind energy conversion system in New Hampshire

    Science.gov (United States)

    Lockwood, J.; Kraft, G.; Pregent, G.; Smukler, L.

    1981-08-01

    Concern over conventional energy costs and supplies is currently strong, particularly in New England region where eighty percent of the total energy is oil based; furthermore, forty percent of this region's total energy is OPEC oil. These figures contrast with national averages of forty-seven and thirteen percent, respectively (1). The quest to develop alternative and renewable energy sources indigenous to New England is understandable in light of these figures. The wind is one such source. The study of wind energy can be divided into three basic areas; these are technical, legal-institutional, and financial. The technical area encompasses collection and analysis of wind data, selection and installation of wind turbines and peripheral equipment, and operation and maintenance. The legal-institutional area encompasses the resolution of such issues as land use policies, power contracts, and state and federal regulations. The financial area encompasses the examination of investment opportunities made available by various site-machine combinations and the selling of such opportunities to the investment community.

  14. Heat to electricity conversion by cold carrier emissive energy harvesters

    International Nuclear Information System (INIS)

    This paper suggests a method to convert heat to electricity by the use of devices called cold carrier emissive energy harvesters (cold carrier EEHs). The working principle of such converters is explained and theoretical power densities and efficiencies are calculated for ideal devices. Cold carrier EEHs are based on the same device structure as hot carrier solar cells, but works in an opposite way. Whereas a hot carrier solar cell receives net radiation from the sun and converts some of this radiative heat flow into electricity, a cold carrier EEH sustains a net outflux of radiation to the surroundings while converting some of the energy supplied to it into electricity. It is shown that the most basic type of cold carrier EEHs have the same theoretical efficiency as the ideal emissive energy harvesters described earlier by Byrnes et al. In the present work, it is also shown that if the emission from the cold carrier EEH originates from electron transitions across an energy gap where a difference in the chemical potential of the electrons above and below the energy gap is sustained, power densities slightly higher than those given by Byrnes et al. can be achieved

  15. Offshore Hydrokinetic Energy Conversion for Onshore Power Generation

    Science.gov (United States)

    Jones, Jack A.; Chao, Yi

    2009-01-01

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

  16. Heat to electricity conversion by cold carrier emissive energy harvesters

    Energy Technology Data Exchange (ETDEWEB)

    Strandberg, Rune [Department of Engineering Sciences, University of Agder, Jon Lilletuns vei 9, 4879 Grimstad (Norway)

    2015-12-07

    This paper suggests a method to convert heat to electricity by the use of devices called cold carrier emissive energy harvesters (cold carrier EEHs). The working principle of such converters is explained and theoretical power densities and efficiencies are calculated for ideal devices. Cold carrier EEHs are based on the same device structure as hot carrier solar cells, but works in an opposite way. Whereas a hot carrier solar cell receives net radiation from the sun and converts some of this radiative heat flow into electricity, a cold carrier EEH sustains a net outflux of radiation to the surroundings while converting some of the energy supplied to it into electricity. It is shown that the most basic type of cold carrier EEHs have the same theoretical efficiency as the ideal emissive energy harvesters described earlier by Byrnes et al. In the present work, it is also shown that if the emission from the cold carrier EEH originates from electron transitions across an energy gap where a difference in the chemical potential of the electrons above and below the energy gap is sustained, power densities slightly higher than those given by Byrnes et al. can be achieved.

  17. 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...... distance transmission of electric energy. In many applications the total size of filter components (capacitors and inductors) can be reduced compared to voltage driven topologies. One application is an audio amplifier arranged to drive a loudspeaker....... 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...

  18. Complex metal borohydrides: multifunctional materials for energy storage and conversion.

    Science.gov (United States)

    Mohtadi, Rana; Remhof, Arndt; Jena, Puru

    2016-09-01

    With the limited supply of fossil fuels and their adverse effect on the climate and the environment, it has become a global priority to seek alternate sources of energy that are clean, abundant, and sustainable. While sources such as solar, wind, and hydrogen can meet the world's energy demand, considerable challenges remain to find materials that can store and/or convert energy efficiently. This topical review focuses on one such class of materials, namely, multi-functional complex metal borohydrides that not only have the ability to store sufficient amount of hydrogen to meet the needs of the transportation industry, but also can be used for a new generation of metal ion batteries and solar cells. We discuss the material challenges in all these areas and review the progress that has been made to address them, the issues that still need to be resolved and the outlook for the future. PMID:27384871

  19. Complex metal borohydrides: multifunctional materials for energy storage and conversion

    Science.gov (United States)

    Mohtadi, Rana; Remhof, Arndt; Jena, Puru

    2016-09-01

    With the limited supply of fossil fuels and their adverse effect on the climate and the environment, it has become a global priority to seek alternate sources of energy that are clean, abundant, and sustainable. While sources such as solar, wind, and hydrogen can meet the world’s energy demand, considerable challenges remain to find materials that can store and/or convert energy efficiently. This topical review focuses on one such class of materials, namely, multi-functional complex metal borohydrides that not only have the ability to store sufficient amount of hydrogen to meet the needs of the transportation industry, but also can be used for a new generation of metal ion batteries and solar cells. We discuss the material challenges in all these areas and review the progress that has been made to address them, the issues that still need to be resolved and the outlook for the future.

  20. Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 3: Energy conversion subsystems and components. Part 3: Gasification, process fuels, and balance of plant

    Science.gov (United States)

    Boothe, W. A.; Corman, J. C.; Johnson, G. G.; Cassel, T. A. V.

    1976-01-01

    Results are presented of an investigation of gasification and clean fuels from coal. Factors discussed include: coal and coal transportation costs; clean liquid and gas fuel process efficiencies and costs; and cost, performance, and environmental intrusion elements of the integrated low-Btu coal gasification system. Cost estimates for the balance-of-plant requirements associated with advanced energy conversion systems utilizing coal or coal-derived fuels are included.

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

    Science.gov (United States)

    Beecher, D. T.

    1976-01-01

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

  2. Use of semiconductors for conversion of solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Arutyunyan, V.M.; Sarkisyan, A.G.; Panosyan, Z.R.

    1981-10-01

    Approximately 100 solar electrical stations (SES) operate in the USSR. An experimental base in the Crimea, an industrial SES with a power of 5000 kW, will be created. Solar equipment for heating and for boiling water, its desalting and for obtaining steam were developed. Solar water heaters find use at agricultural enterprises, sanatoriums, laundries, bathhouses, etc.''Solar homes'' of various designs are constructed in Uzbekistan, Turkestan, Tajikistan and in the southern Ukraine. In Yerevan, at the Armyanskiy Heliocenter, construction is completed of installations where parabolic mirrors produce a temperature in the solar furnace which melts the most difficult to fuse materials, making it possible to synthesize super-pure materials. Use of semiconductor solar batteries under terrestial conditions is costly. Silicon batteries have an efficiency of approx.12% and a battery of gallium arsenide-aluminum heterophoto elements has an efficiency of approx.20%. One of the means of lowering the price of solar electrical energy is the use of electrochemical methods of converting solar energy. This plan considers the possibility of converting solar energy into electrochemical elements of the regenerative type. An energy diagram of a regenerative electrochemical element is presented and the method of its functioning is described. The simplicity of creating the required potential barrier by a simple immersion of the semi-conductor electrode into an electrolyte, as well as the possibility of using inexpensive polycrystalline semiconductor films, among those produced by ceramic technology, is among the advantages of liquid solar batteries. The problem of accumulation of energy can be successfully solved if the solar or electrical energy is used for direct decomposition of water into hydrogen and oxygen.

  3. Chemical Expansion: Implications for Electrochemical Energy Storage and Conversion Devices

    DEFF Research Database (Denmark)

    Bishop, S.R.; Marrocchelli, D.; Chatzichristodoulou, Christodoulos;

    2014-01-01

    Many energy-related materials rely on the uptake and release of large quantities of ions, for example, Li+ in batteries, H+ in hydrogen storage materials, and O2− in solid-oxide fuel cell and related materials. These compositional changes often result in large volumetric dilation of the material...... modeling and an overview of factors impacting chemical expansion. We discuss the implications of chemical expansion for mechanical stability and functionality in the energy applications above, as well as in other oxide-based systems. The use of chemical expansion as a new means to probe other materials...

  4. 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.

  5. Silicon Schottky photovoltaic diodes for solar energy conversion

    Science.gov (United States)

    Anderson, W. A.

    1975-01-01

    Various factors in Schottky barrier solar cell fabrication are evaluated in order to improve understanding of the current flow mechanism and to isolate processing variables that improve efficiency. Results of finger design, substrate resistivity, surface finishing and activation energy studies are detailed. An increased fill factor was obtained by baking of the vacuum system to remove moisture.

  6. Streaming Potential and Energy Conversion in Nanochannel Grafted With Poly-Zwitterion Brushes

    Science.gov (United States)

    Patwary, Jahin; Chen, Guang; Das, Siddhartha

    2015-11-01

    Here we study the streaming potential and electrochemomechanical energy conversion in nanochannels grafted with poly-zwitterion (PZ) brushes. PZs are polymer molecules consisting of negative and positive charge centres simultaneously; depending on the bulk pH, the extent of dissociation differs at each of these charge centres, yielding a particular net charge on the PZ molecule. This PZ charge, therefore, develops a pH dependent electrostatics of the PZ brushes grafted at the naochannel walls. We develop a self-consistent field theory model to calculate this electrostatics by appropriately accounting for the explicit hydrogen ion concentration. Secondly, we use this electrostatics to calculate the streaming potential and the resulting electrochemomechanical energy conversion in nanochannels grafted with poly-zwitterion (PZ) brushes. Our results indicate distinct influences of pH, bulk ion concentration, and the ionization parameters of the PZs in regulating the nanochannel energy conversion. Bridge to the Doctorate Fellowship - LSAMP Committee.

  7. Dose conversion coefficients for high-energy photons, electrons, neutrons and protons

    CERN Document Server

    Sakamoto, Y; Sato, O; Tanaka, S I; Tsuda, S; Yamaguchi, Y; Yoshizawa, N

    2003-01-01

    In the International Commission on Radiological Protection (ICRP) 1990 Recommendations, radiation weighting factors were introduced in the place of quality factors, the tissue weighting factors were revised, and effective doses and equivalent doses of each tissues and organs were defined as the protection quantities. Dose conversion coefficients for photons, electrons and neutrons based on new ICRP recommendations were cited in the ICRP Publication 74, but the energy ranges of theses data were limited and there are no data for high energy radiations produced in accelerator facilities. For the purpose of designing the high intensity proton accelerator facilities at JAERI, the dose evaluation code system of high energy radiations based on the HERMES code was developed and the dose conversion coefficients of effective dose were evaluated for photons, neutrons and protons up to 10 GeV, and electrons up to 100 GeV. The dose conversion coefficients of effective dose equivalent were also evaluated using quality fact...

  8. Study on energy up-conversion in Yb, Ho:YAG crystal

    Institute of Scientific and Technical Information of China (English)

    Lilei Huang(黄莉蕾); Liangneng Wu(邬良能); Yanbin Fu(付晏彬)

    2003-01-01

    Optic parameters, such as the probabilities of radiative and non-radiative transition and the cross-relaxation probability between Yb3+ and Hoa+ ions in Yb,Ho:YAG crystal, are calculated on the basis ofJudd-Ofelt and Dexter theories. The energy up-conversion process is analyzed by solving the transitionrate-equations. The results show that (1) the intensity of the green fluorescence relates to the square ofthe concentration of the active ions; (2) the intensity increases with the concentration of sensitive ions aswell, but the increasing rate goes rather too slow; (3) the efficiency of the energy up-conversion relateswith the speed of the energy up-conversion and the quantum efficiency of the transiting from upper levelto lower level.

  9. Conversion of magnetic energy in the magnetic reconnection layer of a laboratory plasma

    International Nuclear Information System (INIS)

    Magnetic reconnection, in which magnetic field lines break and reconnect to change their topology, occurs throughout the universe. The essential feature of reconnection is that it energizes plasma particles by converting magnetic energy. Despite the long history of reconnection research, how this energy conversion occurs remains a major unresolved problem in plasma physics. Here we report that the energy conversion in a laboratory reconnection layer occurs in a much larger region than previously considered. The mechanisms for energizing plasma particles in the reconnection layer are identified, and a quantitative inventory of the converted energy is presented for the first time in a well defined reconnection layer; 50% of the magnetic energy is converted to particle energy, 2/3 of which transferred to ions and 1/3 to electrons. Our results are compared with simulations and space measurements, for a key step toward resolving one of the most important problems in plasma physics

  10. Conversion of municipal solid waste to energy, Jacksonville, Florida

    Science.gov (United States)

    Frounfelker, R.; Belencan, H.

    1982-02-01

    A 227 megagram per day prototype auger combustor system is described and performance tests are discussed. The system is a two chamber, starved-air incinerator so named because of the auger located within the primary chamber which tumbles and moves the waste through the system. The feasibility evaluation of resource recovery in the city of Jacksonville, Florida, involved the determination of the following: (1) the amount and characteristics of the solid waste; (2) the location and requirement of candidate energy customers and materials markets; (3) the applicable incineration/heat recovery and resource recovery technologies; and (4) the institutional, legal, and environmental requirements for constructing a facility. The marketing plan developd to define the specific steps required to employ a waste-to-energy technology in the Jacksonville area is also discussed.

  11. Thermoelectric Energy Conversion Technology for High-Altitude Airships

    Science.gov (United States)

    Choi, Sang H.; Elliott, James R.; King, Glen C.; Park, Yeonjoon; Kim, Jae-Woo; Chu, Sang-Hyon

    2011-01-01

    The High Altitude Airship (HAA) has various application potential and mission scenarios that require onboard energy harvesting and power distribution systems. The power technology for HAA maneuverability and mission-oriented applications must come from its surroundings, e.g. solar power. The energy harvesting system considered for HAA is based on the advanced thermoelectric (ATE) materials being developed at NASA Langley Research Center. The materials selected for ATE are silicon germanium (SiGe) and bismuth telluride (Bi2Te3), in multiple layers. The layered structure of the advanced TE materials is specifically engineered to provide maximum efficiency for the corresponding range of operational temperatures. For three layers of the advanced TE materials that operate at high, medium, and low temperatures, correspondingly in a tandem mode, the cascaded efficiency is estimated to be greater than 60 percent.

  12. Energy and environmental analysis of a rapeseed biorefinery conversion process

    DEFF Research Database (Denmark)

    Boldrin, Alessio; Balzan, Alberto; Astrup, Thomas Fruergaard

    2013-01-01

    mechanisms determining the fate of products, lost opportunities and marginal productions. The results show that introduction of enzymatic transesterification and improved oil extraction procedure result in environmental benefits compared to a traditional process. Utilization of rapeseed straw seems to have......)-based environmental assessment of a Danish biorefinery system was carried out to thoroughly analyze and optimize the concept and address future research. The LCA study was based on case-specific mass and energy balances and inventory data, and was conducted using consequential LCA approach to take into account market...... positive effects on the greenhouse gases (GHG) footprint of the biorefinery system, with improvements in the range of 9 % to 29 %, depending on the considered alternative. The mass and energy balances showed the potential for improvement of straw treatment processes (hydrothermal pre-treatment and dark...

  13. Improved Energy Conversion for Doubly Fed Wind Generators

    OpenAIRE

    Smith, A. C.; Todd, R.; Barnes, M; Tavner, P.J.

    2006-01-01

    There is currently significant interest in offshore wind turbines up to 5 MW. One of the preferred options is doubly fed slip-ring generators. Turbine manufacturers have proposed an operating scheme for low speeds that is claimed to improve the overall energy extraction from the wind. This paper aims to examine the performance benefits for this new operational mode on a small experimental rig, confirmed by simulation, and to provide a fundamental understanding of the differences in the genera...

  14. Thermal-to-electric energy conversion using ferroelectric film capacitors

    Science.gov (United States)

    Kozyrev, A. B.; Platonov, R. A.; Soldatenkov, O. I.

    2014-10-01

    The capacitive ferroelectric thermoelectric converter harvesting electrical energy through non-linear capacitance variation caused by changes in temperature is analyzed. The ferroelectric material used was the thin (0.5 μm) Ba0.3Sr0.7TiO3 film. On the basis of experimental dependencies of the ferroelectric film permittivity on temperature ranging from 100 K to 350 K under different electric fields up to 80 V/μm, the optimum values of operating temperatures and electric field for the energy harvesting optimization were determined. For the temperature oscillations of ±15 K around room temperature and electric field about 40 V/μm, the harvested energy was estimated as 30 mJ/cm3. It is shown that the use of thin ferroelectric films for rapid capacitance variation versus temperature and microelectromechanical systems for fast temperature modulations may be a relevant solution for creation of small power scale generators for portable electronics.

  15. Parametric investigation of nano-gap thermophotovoltaic energy conversion

    Science.gov (United States)

    Lau, Japheth Z.-J.; Bong, Victor N.-S.; Wong, Basil T.

    2016-03-01

    Nano-gap thermophotovoltaic energy converters have the potential to be excellent generators of electrical power due to the near-field radiative effect which enhances the transfer of energy from one medium to another. However, there is still much to learn about this new form of energy converter. This paper seeks to investigate three parameters that affect the performance of nano-gap thermophotovoltaic devices: the emitter material, the thermophotovoltaic cell material, and the cell thickness. Furthermore, the temperature profiles in insulated thin films (cells exposed to below-band gap near-field radiation) are analysed. It was discovered that an effective emitter material is one that has a high generalised emissivity value and is also able to couple with the TPV cell material through surface polaritons while a cell material's electrical properties and its thickness has heavy bearing on its internal quantum efficiency. In regards to the temperature profile, the heat-flux absorbed causes a rise in temperature across the thin film, but is insufficient to generate a temperature gradient across the film.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-10-29

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

  17. Thermal-to-electric energy conversion using ferroelectric film capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Kozyrev, A. B.; Platonov, R. A.; Soldatenkov, O. I. [Saint-Petersburg State Electrotechnical University, 5 Professor Popov Street, St-Petersburg 197376 (Russian Federation)

    2014-10-28

    The capacitive ferroelectric thermoelectric converter harvesting electrical energy through non-linear capacitance variation caused by changes in temperature is analyzed. The ferroelectric material used was the thin (0.5 μm) Ba{sub 0.3}Sr{sub 0.7}TiO{sub 3} film. On the basis of experimental dependencies of the ferroelectric film permittivity on temperature ranging from 100 K to 350 K under different electric fields up to 80 V/μm, the optimum values of operating temperatures and electric field for the energy harvesting optimization were determined. For the temperature oscillations of ±15 K around room temperature and electric field about 40 V/μm, the harvested energy was estimated as 30 mJ/cm{sup 3}. It is shown that the use of thin ferroelectric films for rapid capacitance variation versus temperature and microelectromechanical systems for fast temperature modulations may be a relevant solution for creation of small power scale generators for portable electronics.

  18. Large impact of reorganization energy on photovoltaic conversion due to interfacial charge-transfer transitions.

    Science.gov (United States)

    Fujisawa, Jun-ichi

    2015-05-14

    Interfacial charge-transfer (ICT) transitions are expected to be a novel charge-separation mechanism for efficient photovoltaic conversion featuring one-step charge separation without energy loss. Photovoltaic conversion due to ICT transitions has been investigated using several TiO2-organic hybrid materials that show organic-to-inorganic ICT transitions in the visible region. In applications of ICT transitions to photovoltaic conversion, there is a significant problem that rapid carrier recombination is caused by organic-inorganic electronic coupling that is necessary for the ICT transitions. In order to solve this problem, in this work, I have theoretically studied light-to-current conversions due to the ICT transitions on the basis of the Marcus theory with density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. An apparent correlation between the reported incident photon-to-current conversion efficiencies (IPCE) and calculated reorganization energies was clearly found, in which the IPCE increases with decreasing the reorganization energy consistent with the Marcus theory in the inverted region. This activation-energy dependence was systematically explained by the equation formulated by the Marcus theory based on a simple excited-state kinetic scheme. This result indicates that the reduction of the reorganization energy can suppress the carrier recombination and enhance the IPCE. The reorganization energy is predominantly governed by the structural change in the chemical-adsorption moiety between the ground and ICT excited states. This work provides crucial knowledge for efficient photovoltaic conversion due to ICT transitions. PMID:25892453

  19. A Biomimetic Haptic Sensor

    Directory of Open Access Journals (Sweden)

    Ben Mitchinson

    2008-11-01

    Full Text Available The design and implementation of the periphery of an artificial whisker sensory system is presented. It has been developed by adopting a biomimetic approach to model the structure and function of rodent facial vibrissae. The artificial vibrissae have been formed using composite materials and have the ability to be actively moved or whisked. The sensory structures at the root of real vibrissae has been modelled and implemented using micro strain gauges and Digital Signal Processors. The primary afferents and vibrissal trigeminal ganglion have been modelled using empirical data taken from electrophysiological measurements, and implemented in real-time using a Field Programmable Gate Array. Pipelining techniques were employed to maximise the utility of the FPGA hardware. The system is to be integrated into a more complete whisker sensory model, including neural structures within the central nervous system, which can be used to orient a mobile robot.

  20. Biomimetic thin film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.

    1995-09-01

    Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

  1. Reaction Force Control of a Linear Electrical Generator for Direct Drive Wave Energy Conversion

    OpenAIRE

    Shek, J.K.H.; Macpherson, D.E.; Mueller, M.A.; Xiang, J.

    2007-01-01

    Direct drive wave energy converters have been proposed in view of the disadvantage of mechanical complexity and low conversion efficiencies in conventional wave energy converters. By directly coupling a linear generator to a reciprocating wave energy device, it is suggested that direct drive power take-off could be a viable alternative to hydraulic- and pneumatic-based systems. To further realise the benefits of a direct drive system, a control scheme based on reaction force control to maximi...

  2. Wave Energy Conversion: Direct Coupled Point Absorber in Heave with Induction Machine as Power Take Off

    OpenAIRE

    Skjervheim, Ottar

    2007-01-01

    In the area of offshore renewable, wave energy can give great contribution. There has been research for developing wave energy converters since the late eighteenth century when the first patent was applied for in 1799 [1], without any remarkable breakthrough. This master thesis will discuss the topic of wave energy conversion by a point absorber in heave with a directly coupled induction machine power take off. A wave to wire approach has been attempted in this thesis. The tool needed is a h...

  3. Control of Linear Electrical Generators for Direct Drive Wave Energy Conversion

    OpenAIRE

    Shek, Jonathan

    2006-01-01

    Linear generators have been proposed as a suitable power take-off system for direct drive wave energy conversion. Coupled directly to a reciprocating wave energy device, it is suggested that linear generators could be a viable alternative to hydraulic and pneumatic systems. This paper discusses the challenges involved in control of a direct drive wave energy converter, predominantly for maximum power extraction through electrical means. It highlights characteristics of linear generator contro...

  4. Ab initio design of nanostructures for solar energy conversion: a case study on silicon nitride nanowire

    OpenAIRE

    Pan, Hui

    2014-01-01

    Design of novel materials for efficient solar energy conversion is critical to the development of green energy technology. In this work, we present a first-principles study on the design of nanostructures for solar energy harvesting on the basis of the density functional theory. We show that the indirect band structure of bulk silicon nitride is transferred to direct bandgap in nanowire. We find that intermediate bands can be created by doping, leading to enhancement of sunlight absorption. W...

  5. Effect of topographic barriers on the rates of available potential energy conversion of the oceans

    Science.gov (United States)

    Stewart, K. D.; Saenz, J. A.; Hogg, A. McC.; Hughes, G. O.; Griffiths, R. W.

    2014-04-01

    Determining the energy budget of the oceans requires evaluating the rates of available potential energy conversion in the circulation. Calculating these conversion rates depends upon the definition of an appropriate “reference” state of the density field, but this definition is complicated in the oceans by the presence of bottom topography. The trapping of dense fluid by topographic barriers means that there are multiple definitions for the reference state. The approach taken in this paper is to examine the sensitivity of the available potential energy budget to several methods for defining the reference state. The first method makes allowances for restrictions imposed on the flow by topography, however it is computationally intensive. The second method is proposed as an inexpensive alternative to the first. These new methods are used to evaluate the energy budget of a model overturning circulation maintained by surface buoyancy forcing. The results are compared with those obtained from two existing methods; one which employs an adiabatic resorting procedure ignoring topography, and one which uses a reference profile developed from the horizontal average of the density field. In our model, the rates of available potential energy conversion are insensitive to the reference state definition providing the reference state is developed from an adiabatic resorting of the domain. These results suggest that any of the adiabatic resorting methods proposed here would be sufficient to evaluate the rates of energy conversion in the ocean.

  6. The 20 year evolution of an energy conversion course at the United States Military Academy

    International Nuclear Information System (INIS)

    Over the past several years, an energy conversion course offered by the Mechanical Engineering Program at the United States Military Academy in West Point, New York, has evolved into a cohesive series of lessons addressing three general topical areas: advanced thermodynamics, advanced mechanical system analysis, and direct energy conversion systems. Mechanical engineering majors enroll in Energy Conversion Systems (ME 472) during the fall semester of their senior year as an advanced elective. ME 472 builds directly on the material covered in Thermodynamics (EM 301) taken during the student's junior year. In the first segment of ME 472, the students study advanced thermodynamic topics including exergy and combustion analyses. The students then analyze various mechanical systems including refrigeration systems, internal combustion engines, boilers, and fossil fuel fired steam and gas turbine combined power plants. Exergetic efficiencies of various equipment and systems are determined. The final portion of the course covers direct energy conversion technology, including fuel cells, photovoltaics, thermoelectricity, thermionics and magnetohydrodynamics. Supplemental lessons on energy storage, semi-conductors and nonreactive energy sources (such as solar collectors, wind turbines, and hydroelectric plants) are included here. This paper discusses the evolution of ME 472 since its inception and explains the motivations for the course's progress

  7. Analysis Of Functional Stability Of The Triphased Asynchronous Generator Used In Conversion Systems Of A Eolian Energy Into Electric Energy

    Directory of Open Access Journals (Sweden)

    Ion VONCILA

    2003-12-01

    Full Text Available This paper presents a study of the influence of the main perturbation agent over the functional stability of the triphased asynchronous generator (for the two alternative: with coiled and short circuit rotor, used for the conversion systems from a eolian energy into electric energy.

  8. A History of Geothermal Energy Research and Development in the United States. Energy Conversion 1976-2006

    Energy Technology Data Exchange (ETDEWEB)

    Mines, Gregory L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2010-09-01

    This report, the last in a four-part series, summarizes significant research projects performed by the U.S. Department of Energy (DOE) over 30 years to overcome challenges in energy conversion and to make generation of electricity from geothermal resources more cost-competitive.

  9. Advanced energy sources and conversion techniques. Proceedings of a seminar. Volume 1. [35 papers

    Energy Technology Data Exchange (ETDEWEB)

    None

    1958-11-01

    The Seminar was organized as a series of tutorial presentations and round table discussions on a technical level to implement the following: (a) to identify and explore present and projected needs for energy sources and conversion techniques for military applications; (b) to exchange information on current and planned efforts in these fields; (c) to examine the effect of anticipated scientific and technological advances on these efforts; and (d) to present suggested programs aimed at satisfying the military needs for energy sources and conversion techniques. Volume I contains all of the unclassified papers presented at the Seminar. (W.D.M.)

  10. Symmetry, vibrational energy redistribution and vibronic coupling: The internal conversion processes of cycloketones

    DEFF Research Database (Denmark)

    Kuhlman, Thomas Scheby; Sauer, Stephan P.A.; Sølling, Theis I.;

    2012-01-01

    In this paper, we discern two basic mechanisms of internal conversion processes; one direct, where immediate activation of coupling modes leads to fast population transfer and one indirect, where internal vibrational energy redistribution leads to equidistribution of energy, i.e., ergodicity, and...... slower population transfer follows. Using model vibronic coupling Hamiltonians parameterized on the basis of coupled-cluster calculations, we investigate the nature of the Rydberg to valence excited-state internal conversion in two cycloketones, cyclobutanone and cyclopentanone. The two basic mechanisms...

  11. Polymer/Graphene Hybrids for Advanced Energy-Conversion and -Storage Materials.

    Science.gov (United States)

    Cui, Linfan; Gao, Jian; Xu, Tong; Zhao, Yang; Qu, Liangti

    2016-04-20

    Polymer/graphene-based materials with interesting physical and chemical properties have been attracting considerable attention and have been shown to have great potential as active materials in the field of energy conversion and storage. In this review, we focus on recent significant advances in the fabrication and application of polymer/graphene hybrids as electrocatalysts and electrode materials. Synthetic strategies and application of these materials in energy conversion and storage are presented, particularly in devices such as fuel cells, actuators, and supercapacitors, accompanied with a discussion of the challenges and research directions necessary for the future development of polymer/graphene hybrids.

  12. Advances in graphene-based semiconductor photocatalysts for solar energy conversion: fundamentals and materials engineering

    Science.gov (United States)

    Xie, Xiuqiang; Kretschmer, Katja; Wang, Guoxiu

    2015-08-01

    Graphene-based semiconductor photocatalysis has been regarded as a promising technology for solar energy storage and conversion. In this review, we summarized recent developments of graphene-based photocatalysts, including preparation of graphene-based photocatalysts, typical key advances in the understanding of graphene functions for photocatalytic activity enhancement and methodologies to regulate the electron transfer efficiency in graphene-based composite photocatalysts, by which we hope to offer enriched information to harvest the utmost fascinating properties of graphene as a platform to construct efficient graphene-based composite photocatalysts for solar-to-energy conversion.

  13. Energy balance of biofuel production from biological conversion of crude glycerol.

    Science.gov (United States)

    Zhang, Xiaolei; Yan, Song; Tyagi, Rajeshwar D; Surampalli, Rao Y; Valéro, Jose R

    2016-04-01

    Crude glycerol, a by-product of biodiesel production, has gained significant attention as a carbon source for biofuel production. This study evaluated the energy balance of biodiesel, hydrogen, biogas, and ethanol production from 3.48 million L of crude glycerol (80% w/v). The conversion efficiency (energy output divided by energy invested) was 1.16, 0.22, 0.27, and 0.40 for the production of biodiesel, hydrogen, biogas, and ethanol respectively. It was found that the use of crude glycerol for biodiesel production was an energy gain process, with a positive energy balance and conversion efficiency of greater than 1. The energy balance revealed a net energy gain of 5226 GJ per 1 million kg biodiesel produced. Production of hydrogen, biogas and ethanol from crude glycerol were energy loss processes. Therefore, the conversion of crude glycerol to lipids and subsequently to biodiesel is suggested to be a better option compared to hydrogen, biogas, or ethanol production with respect to energy balance.

  14. Challenges of coal conversion for decarbonized energy in Poland

    Energy Technology Data Exchange (ETDEWEB)

    Sciazko, Marek; Jalosinski, Krzysztof; Majchrzak, Henryk; Michalski, Mieczyslaw; Tymowski, Henryk; Witos, Tadeusz; Wroblewska, Elzbieta

    2010-09-15

    Carbon dioxide is considered to be the main challenge for the coal-based power generation as well as for any other industrial application of coal. Poland's energy sector is primarily based on coal combustion that covers almost 90% of demand. Future development of that sector depends on the restriction on value of carbon dioxide emission or trading allowances. There are two main technological approaches to development of new coal based generation capacity, namely: gasification and pre-combustion capture; supercritical combustion and post-combustion capture. The current situation in development of three this type projects in Poland is presented.

  15. Combined chemical looping for energy storage and conversion

    Science.gov (United States)

    Galvita, Vladimir V.; Poelman, Hilde; Marin, Guy B.

    2015-07-01

    Combined chemical looping was demonstrated as novel concept of energy storage in a laboratory scale test. The proposed technology is able to store and release energy from redox chemical looping reactions combined with calcium looping. This process uses Fe3O4 and CaO, two low cost and environmentally friendly materials, while CH4 + CO2 serve as feed. During the reduction of Fe3O4 by CH4, both formation of carbon and metallic iron occur. CO2 acts as mediation gas to facilitate the metal/metal oxide redox reaction and carbon gasification into CO. CaO, on the other hand, is used for storage of CO2. Upon temperature rise, CaCO3 releases CO2, which re-oxidizes the carbon deposits and reduced Fe, thus producing carbon monoxide. The amount of produced CO is higher than the theoretical amount for Fe3O4, because carbon deposits from CH4 equally contribute to the CO yield. After each redox cycle, the material is regenerated, so that it can be used repeatedly, providing a stable process.

  16. Twisted Savonius turbine based marine current energy conversion system

    Science.gov (United States)

    Hassan, Md. Imtiaj

    The Ocean Network Seafloor Instrumentation (ONSFI) Project is a multidisciplinary research and development project that aims to design, fabricate and validate a proof-of-concept seafloor array of wireless marine sensors for use in monitoring seabed processes. The sensor pods, known as Seaformatics, will be powered by ocean bottom currents and will be able to communicate with each other and to the Internet through surface master units to facilitate observation of the ocean floor from the shore. This thesis explores the use of the twisted Savonius turbine as a means of converting the kinetic energy of the free flowing water into electrical energy for the pods. This will eliminate the need for battery replacement. A physical model of the turbine was constructed and tested in the Water Flume at the Marine Institute of Memorial University and in the Wind Tunnel in the Engineering Building at Memorial University. A mathematical model of the turbine was constructed in SolidWorks. This was tested in the Computational Fluid Dynamics or CFD software FLOW-3D. Experimental results were compared with CFD results and the agreement was reasonable. A twisted Savonius turbine emulator was developed to test a dc-dc boost converter. A low cost microcontroller based MPPT algorithm was developed to obtain maximum power from the turbine. Overall the thesis shows that the twisted Savonius turbine can provide the power needed by the sensor pods. It also shows that CFD is a viable way to study the performance of the Savonius type of turbine.

  17. Biomimetic Nanotechnology: A Powerful Means to address Global Challenges

    CERN Document Server

    Gebeshuber, Ille C

    2010-01-01

    Biomimetic nanotechnology is a prominent research area at the meeting place of life sciences with engineering and physics: it is a continuously growing field that deals with knowledge transfer from biology to nanotechnology. Biomimetic nanotechnology is a field that has the potential to substantially support successful mastering of major global challenges. The Millennium Project was commissioned by the United Nations Secretary-General in 2002 to develop a concrete action plan for the world to reverse the grinding poverty, hunger and disease affecting billions of people. It states 15 Global Challenges: sustainable development, water, population and resources, democratization, long-term perspectives, information technology, the rich-poor gap, health, capacity to decide, peace and conflict, status of women, transnational crime, energy, science and technology and global ethics. The possible contributions to master these challenges with the help of biomimetic nanotechnology will be discussed in detail.

  18. Analysis of gas turbine systems for sustainable energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Anheden, Marie

    2000-02-01

    Increased energy demands and fear of global warming due to the emission of greenhouse gases call for development of new efficient power generation systems with low or no carbon dioxide (CO{sub 2}) emissions. In this thesis, two different gas turbine power generation systems, which are designed with these issues in mind, are theoretically investigated and analyzed. In the first gas turbine system, the fuel is combusted using a metal oxide as an oxidant instead of oxygen in the air. This process is known as Chemical Looping Combustion (CLC). CLC is claimed to decrease combustion exergy destruction and increase the power generation efficiency. Another advantage is the possibility to separate CO{sub 2} without a costly and energy demanding gas separation process. The system analysis presented includes computer-based simulations of CLC gas turbine systems with different metal oxides as oxygen carriers and different fuels. An exergy analysis comparing the exergy destruction of the gas turbine system with CLC and conventional combustion is also presented. The results show that it is theoretically possible to increase the power generation efficiency of a simple gas turbine system by introducing CLC. A combined gas/steam turbine cycle system with CLC is, however, estimated to reach a similar efficiency as the conventional combined cycle system. If the benefit of easy and energy-efficient CO{sub 2} separation is accounted for, a CLC combined cycle system has a potential to be favorable compared to a combined cycle system with CO{sub 2} separation. In the second investigation, a solid, CO{sub 2}-neutral biomass fuel is used in a small-scale externally fired gas turbine system for cogeneration of power and district heating. Both open and closed gas turbines with different working fluids are simulated and analyzed regarding thermodynamic performance, equipment size, and economics. The results show that it is possible to reach high power generation efficiency and total (power

  19. Theoretical maximum efficiency of solar energy conversion in plasmonic metal-semiconductor heterojunctions.

    Science.gov (United States)

    Cushing, Scott K; Bristow, Alan D; Wu, Nianqiang

    2015-11-28

    Plasmonics can enhance solar energy conversion in semiconductors by light trapping, hot electron transfer, and plasmon-induced resonance energy transfer (PIRET). The multifaceted response of the plasmon and multiple interaction pathways with the semiconductor makes optimization challenging, hindering design of efficient plasmonic architectures. Therefore, in this paper we use a density matrix model to capture the interplay between scattering, hot electrons, and dipole-dipole coupling through the plasmon's dephasing, including both the coherent and incoherent dynamics necessary for interactions on the plasmon's timescale. The model is extended to Shockley-Queisser limit calculations for both photovoltaics and solar-to-chemical conversion, revealing the optimal application of each enhancement mechanism based on plasmon energy, semiconductor energy, and plasmon dephasing. The results guide application of plasmonic solar-energy harvesting, showing which enhancement mechanism is most appropriate for a given semiconductor's weakness, and what nanostructures can achieve the maximum enhancement.

  20. 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.

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

    International Nuclear Information System (INIS)

    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

  2. One-dimension-based spatially ordered architectures for solar energy conversion.

    Science.gov (United States)

    Liu, Siqi; Tang, Zi-Rong; Sun, Yugang; Colmenares, Juan Carlos; Xu, Yi-Jun

    2015-08-01

    The severe consequences of fossil fuel consumption have resulted in a need for alternative sustainable sources of energy. Conversion and storage of solar energy via a renewable method, such as photocatalysis, holds great promise as such an alternative. One-dimensional (1D) nanostructures have gained attention in solar energy conversion because they have a long axis to absorb incident sunlight yet a short radial distance for separation of photogenerated charge carriers. In particular, well-ordered spatially high dimensional architectures based on 1D nanostructures with well-defined facets or anisotropic shapes offer an exciting opportunity for bridging the gap between 1D nanostructures and the micro and macro world, providing a platform for integration of nanostructures on a larger and more manageable scale into high-performance solar energy conversion applications. In this review, we focus on the progress of photocatalytic solar energy conversion over controlled one-dimension-based spatially ordered architecture hybrids. Assembly and classification of these novel architectures are summarized, and we discuss the opportunity and future direction of integration of 1D materials into high-dimensional, spatially organized architectures, with a perspective toward improved collective performance in various artificial photoredox applications.

  3. Characterization of energy conversion of multiferroic PFN and PFN:Mn

    Directory of Open Access Journals (Sweden)

    Lucjan Kozielski

    2013-12-01

    Full Text Available Characterization of energy conversion of multiferroic materials is concerned with multifunctional properties of materials, a topic that is fascinating from the scientific point of view and important for the modern technology. The complex characterization of multiferroic structures suffers at present from lack of a systematic experimental approach and deficiency of multifunctional magnetoelectric properties testing capabilities. Compactness and high frequency energy conversion capacity are the main reasons of invention and improvement of sophisticated materials which are prepared for high-speed computer memories and broadband transducer devices. As a consequence, one can easily notice an intense search for new materials for generation, transformation and amplification of magnetic and electric energies. In this scenario, the combination of excellent piezoelectric and magnetic properties makes lead iron niobate Pb(Fe1/2Nb1/2O3 (PFN an attractive host material for application in integrated magnetoelectric energy conversion applications. PFN multiferroic materials are attractive for commercial electroceramics due to high value of dielectric permittivity and magnetoelectric coefficients as well as relatively easy synthesis process. However, synthesis of PFN ceramics is mostly connected with formation of the secondary unwanted pyrochlore phase associated with dramatic decrease of ferroelectric properties. The authors have successfully reduced this negative phenomenon by Mn doping and finally present high piezoelectric and magnetoelectric energy conversion efficiency in fabricated PMFN ceramics.

  4. BIOMIMETIC STRATEGIES IN ORGANIC SYNTHESIS. TERPENES

    OpenAIRE

    V. Kulcitki

    2012-01-01

    The current paper represents an outline of the selected contributions to the biomimetic procedures and approaches for the synthesis of terpenes with complex structure and diverse functionalisation pattern. These include homologation strategies, cyclisations, rearrangements, as well as biomimetic remote functionalisations.

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

    OpenAIRE

    Jye-Chau Su; Cheng-Tao Tsai; Chih-Lung Shen

    2013-01-01

    In this paper, a power supply system for hybrid renewable energy conversion is proposed, which can process PV (photovoltaic) power and wind-turbine energy simultaneously for step-down voltage and high current applications. It is a dual-input converter and mainly contains a PV energy source, a wind turbine energy source, a zero-voltage-switching (ZVS) forward converter, and a current-doubler rectifier. The proposed power supply system has the following advantages: (1) PV-arrays and wind-energy...

  6. Economic Analysis of Large-Scale Wind Energy Conversion Systems in Central Anatolian Turkey

    OpenAIRE

    Genc, Mustafa Serdar

    2010-01-01

    Clean and renewable energies obtaining from sunlight, wind or water around the earth do not make a net contribution of carbon dioxide to the atmosphere. Therefore, these energy sources should be used to protect our world, because of global warming and the injurious effects of carbon emissions. And so, it should be estimated the windy and sunny fields in Turkey, the unit cost of energy output of various wind and solar energy conversion systems. Today, wind energy seems to be reasonable due to...

  7. Electric utility application of wind energy conversion systems on the island of Oahu

    Energy Technology Data Exchange (ETDEWEB)

    Lindley, C.A.; Melton, W.C.

    1979-02-23

    This wind energy application study was performed by The Aerospace Corporation for the Wind Systems Branch of the Department of Energy. The objective was to identify integration problems for a Wind Energy Conversion System (WECS) placed into an existing conventional utility system. The integration problems included environmental, institutional and technical aspects as well as economic matters, but the emphasis was on the economics of wind energy. The Hawaiian Electric Company utility system on the island of Oahu was selected for the study because of the very real potential for wind energy on that island, and because of the simplicity afforded in analyzing that isolated utility.

  8. Evaluation of conversion efficiency of light to hydrogen energy by Anabaena variabilis

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jong Hyun; Hae Shin, Ji; Park, Tai Hyun [School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Kim, Mi-Sun [Biomass Research Team, Korea Institute of Energy Research, Daejeon 305-343 (Korea, Republic of); Jun Sim, Sang [Department of Chemical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2006-05-15

    Cyanobacteria provide an efficient system for producing H{sub 2} from water using solar energy. The energy conversion efficiency can be defined by the ratio of H{sub 2} produced to the light energy absorbed. An IR and opalescent plate method was used to measure the light energy absorbed. Since cyanobacteria absorb light in the visible range but not in the infrared range, the net amount of light energy absorbed by the cells can be estimated by measuring the IR and visible light intensities transmitted through the biochamber. A rectangular biochamber was used for measuring the conversion efficiency from light energy to H{sub 2} energy. A quantum meter and radiometer were used to measure the light intensity transmitted through the chamber. Anabaena variabilis was cultured in a BG11 medium with 3.6mM NaNO{sub 3} and the light intensity was 40-50{mu}mol/m{sup 2}/s in the growth phase and 120-140{mu}mol/m{sup 2}/s in the H{sub 2} production phase. The maximum H{sub 2} production was 50ml for 40h and cell density was 1.2g/l. The H{sub 2} production rate was 4.1ml H{sub 2}/g dry cell weight/h. Based on the light absorbed in the H{sub 2} production phase, the energy conversion efficiency from light to H{sub 2} was 1.5% on average and 3.9% at the maximum. Based on the light energy absorbed in the cell growth and H{sub 2} production phases, the energy conversion efficiency was 1.1% on average. (author)

  9. Maximum efficiency of state-space models of nanoscale energy conversion devices

    Science.gov (United States)

    Einax, Mario; Nitzan, Abraham

    2016-07-01

    The performance of nano-scale energy conversion devices is studied in the framework of state-space models where a device is described by a graph comprising states and transitions between them represented by nodes and links, respectively. Particular segments of this network represent input (driving) and output processes whose properly chosen flux ratio provides the energy conversion efficiency. Simple cyclical graphs yield Carnot efficiency for the maximum conversion yield. We give general proof that opening a link that separate between the two driving segments always leads to reduced efficiency. We illustrate these general result with simple models of a thermoelectric nanodevice and an organic photovoltaic cell. In the latter an intersecting link of the above type corresponds to non-radiative carriers recombination and the reduced maximum efficiency is manifested as a smaller open-circuit voltage.

  10. Maximum efficiency of state-space models of nanoscale energy conversion devices.

    Science.gov (United States)

    Einax, Mario; Nitzan, Abraham

    2016-07-01

    The performance of nano-scale energy conversion devices is studied in the framework of state-space models where a device is described by a graph comprising states and transitions between them represented by nodes and links, respectively. Particular segments of this network represent input (driving) and output processes whose properly chosen flux ratio provides the energy conversion efficiency. Simple cyclical graphs yield Carnot efficiency for the maximum conversion yield. We give general proof that opening a link that separate between the two driving segments always leads to reduced efficiency. We illustrate these general result with simple models of a thermoelectric nanodevice and an organic photovoltaic cell. In the latter an intersecting link of the above type corresponds to non-radiative carriers recombination and the reduced maximum efficiency is manifested as a smaller open-circuit voltage.

  11. Maximum efficiency of state-space models of nanoscale energy conversion devices.

    Science.gov (United States)

    Einax, Mario; Nitzan, Abraham

    2016-07-01

    The performance of nano-scale energy conversion devices is studied in the framework of state-space models where a device is described by a graph comprising states and transitions between them represented by nodes and links, respectively. Particular segments of this network represent input (driving) and output processes whose properly chosen flux ratio provides the energy conversion efficiency. Simple cyclical graphs yield Carnot efficiency for the maximum conversion yield. We give general proof that opening a link that separate between the two driving segments always leads to reduced efficiency. We illustrate these general result with simple models of a thermoelectric nanodevice and an organic photovoltaic cell. In the latter an intersecting link of the above type corresponds to non-radiative carriers recombination and the reduced maximum efficiency is manifested as a smaller open-circuit voltage. PMID:27394100

  12. Conversion of visible light to electrical energy - Stable cadmium selenide photoelectrodes in aqueous electrolytes

    Science.gov (United States)

    Wrighton, M. S.; Ellis, A. B.; Kaiser, S. W.

    1977-01-01

    Stabilization of n-type CdSe to photoanodic dissolution is reported. The stabilization is accomplished by the competitive oxidation of S(--) or S(n)(--) at the CdSe photoanode in an electrochemical cell. Such stabilized cells are shown to sustain the conversion of low energy (not less than 1.7 eV) visible light to electricity with good efficiency and no deterioration of the CdSe photoelectrode or of the electrolyte. The electrolyte undergoes no net chemical change because the oxidation occurring at the photoelectrode is reversed at the cathode. Conversion of monochromatic light at 633 nm to electricity is shown to be up to approximately 9% efficient with output potentials of approximately 0.4 V. Conversion of solar energy to electricity is estimated to be approximately 2% efficient.

  13. Microwave pyrolysis for conversion of materials to energy : A review

    International Nuclear Information System (INIS)

    Full text: The disposal of wastes in Malaysia is becoming a serious problem in many industrialized and public sectors. This is due to the high production of waste such as municipal solid waste, sludge from waste water treatment plants, agricultural waste and other used non-biodegradable products such as plastics and tyres. These wastes although are reused as compost, fuel, recycled and so on, there are still abundant left. These leftovers pose problems such as heavy metal leaching, leachates, green house gas emissions and mosquito breeding grounds. The disposal cost of these wastes sometimes can be costly at up to RM 2,200/ ton such as petroleum sludge by Kualiti Alam. Several methods have been used to convert these residues to energy via thermal treatment such as combustion, incineration and gasification. However, pyrolysis becomes one of the popular methods as the alternative to the wastes disposal recently. Not only energy (as gas) is produced, by-products such as chemical feedstock and solid absorbent can be produced. The use of microwave for pyrolysis, although relatively new for waste treatment, has several advantages compared to conventional heating. This includes easy control of the heating process, time saving, higher heating efficiency, etc. Tyre microwave pyrolysis plant in UK is known as the earliest plant using microwave technology to breakdown polymer in used tyres. Since 1990s, there are many patents for microwave pyrolysis. The processes are based on microwave pyrolysis of waste include coffee hulls, wood, coal, sewage sludge, hospital waste, plastic wastes, corn cobs and rice straw. The most important factors influencing the yield of product during the pyrolysis is temperature in range from 500 to 1000 degree Celsius according to product preference. High temperature favors gas products; whereas lower temperature favors liquid products. Comparatively, microwave pyrolysis produced gas with higher hydrogen and carbon monoxide (syngas) content compared

  14. Photobiological production of hydrogen: a solar energy conversion option

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, P.; Lien, S.; Seibert, M.

    1979-01-01

    This literature survey of photobiological hydrogen production covers the period from its discovery in relatively pure cultures during the early 1930s to the present. The focus is hydrogen production by phototrophic organisms (and their components) which occurs at the expense of light energy and electron-donating substrates. The survey covers the major contributions in the area; however, in many cases, space has limited the degree of detail provided. Among the topics included is a brief historical overview of hydrogen metabolism in photosynthetic bacteria, eucaryotic algae, and cyanobacteria (blue--green algae). The primary enzyme systems, including hydrogenase and nitrogenase, are discussed along with the manner in which they are coupled to electron transport and the primary photochemistry of photosynthesis. A number of in vivo and in vitro photobiological hydrogen evolving schemes including photosynthetic bacterial, green algal, cyanobacterial, two-stage, and cell-free systems are examined in some detail. The remainder of the review discusses specific technical problem areas that currently limit the yield and duration of many of the systems and research that might lead to progress in these specific areas. The final section outlines, in broadest terms, future research directions necessary to develop practical photobiological hydrogen-producing systems. Both whole cell (near- to mid-term) and cell-free (long-term) systems should be emphasized. Photosynthetic bacteria currently show the most promise for near-term applied systems.

  15. Efficient energy conversion in photochromic ruthenium DMSO complexes.

    Science.gov (United States)

    Rachford, Aaron A; Petersen, Jeffrey L; Rack, Jeffrey J

    2006-07-24

    The photochromic compounds trans- and cis-[Ru(tpy)(Mepic)(dmso)](OSO2CF3) (2 and 3, respectively; tpy is 2,2':6',2"-terpyridine; Mepic is 6-methyl-2-pyridinecarboxylate; dmso is dimethyl sulfoxide) and cis-[Ru(tpy)(Brpic)(dmso)](PF6) (4; Brpic is 6-bromo-2-pyridinecarboxylate) were prepared and characterized by single-crystal X-ray crystallography, electrochemistry, NMR, IR, and UV-vis spectroscopy. The geometry labels refer to the relationship between the carboxylate oxygen of the picolinate ligand and dmso. Electrochemical studies reveal that only the trans isomer shows S-to-O isomerization following oxidation of Ru(II) and O-to-S isomerization following reduction of Ru(III). The cis isomers of both complexes feature reversible one-electron Ru(III/II) couples. All complexes undergo phototriggered S-to-O isomerization following MLCT (metal-to-ligand charge transfer) excitation with quantum yields (Phi(S-->O)) of 0.79 (2), 0.011 (3), and 0.014 (4). The methyl group in 2 promotes isomerization by hindering rotation of the dmso ligand about the Ru-S bond. Computational results support this role for the methyl group. Relative energy calculations show that the barrier to rotation is approximately 8 kcal mol(-1). These results suggest that rotation is an important vibration for isomerization in photochromic ruthenium-dmso complexes. PMID:16842000

  16. SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOLID OXIDE FUEL CELL

    Energy Technology Data Exchange (ETDEWEB)

    Steven Shaffer; Sean Kelly; Subhasish Mukerjee; David Schumann; Gail Geiger; Kevin Keegan; John Noetzel; Larry Chick

    2003-12-08

    The objective of Phase I under this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with the option of piped-in water (Demonstration System A). Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine. This technical progress report covers work performed by Delphi from January 1, 2003 to June 30, 2003, under Department of Energy Cooperative Agreement DE-FC-02NT41246. This report highlights technical results of the work performed under the following tasks: Task 1 System Design and Integration; Task 2 Solid Oxide Fuel Cell Stack Developments; Task 3 Reformer Developments; Task 4 Development of Balance of Plant (BOP) Components; Task 5 Manufacturing Development (Privately Funded); Task 6 System Fabrication; Task 7 System Testing; Task 8 Program Management; and Task 9 Stack Testing with Coal-Based Reformate.

  17. Numerical simulation and decomposition of kinetic energy in the Central Mediterranean: insight on mesoscale circulation and energy conversion

    OpenAIRE

    Sorgente, R.; A. Olita; P. Oddo; L. Fazioli; A. Ribotti

    2011-01-01

    The spatial and temporal variability of eddy and mean kinetic energy of the Central Mediterranean region has been investigated, from January 2008 to December 2010, by mean of a numerical simulation mainly to quantify the mesoscale dynamics and their relationships with physical forcing. In order to understand the energy redistribution processes, the baroclinic energy conversion has been analysed, suggesting hypotheses about the drivers of the mesoscale activity in this area. The ocean model us...

  18. Mass-energy balance analysis for estimation of light energy conversion in an integrated system of biological H2 production

    OpenAIRE

    A.I. Gavrisheva; B.F. Belokopytov; V.I. Semina; E.S. Shastik; T.V. Laurinavichene; A.A. Tsygankov

    2015-01-01

    The present study investigated an integrated system of biological H2 production, which includes the accumulation of biomass of autotrophic microalgae, dark fermentation of biomass, and photofermentation of the dark fermentation effluent. Particular emphasis was placed on the estimation of the conversion efficiency of light into hydrogen energy at each stage of this system. For this purpose, the mass and energy balance regularities were applied. The efficiency of the energy transformation from...

  19. Biomimetic self-cleaning surfaces: synthesis, mechanism and applications.

    Science.gov (United States)

    Xu, Quan; Zhang, Wenwen; Dong, Chenbo; Sreeprasad, Theruvakkattil Sreenivasan; Xia, Zhenhai

    2016-09-01

    With millions of years of natural evolution, organisms have achieved sophisticated structures, patterns or textures with complex, spontaneous multifunctionality. Among all the fascinating characteristics observed in biosystems, self-cleaning ability is regarded as one of the most interesting topics in biomimicry because of its potential applications in various fields such as aerospace, energy conversion and biomedical and environmental protection. Recently, in-depth studies have been carried out on various compelling biostructures including lotus leaves, shark skins, butterfly wings and gecko feet. To understand and mimic their self-cleaning mechanisms in artificial structures, in this article, recent progress in self-cleaning techniques is discussed and summarized. Based on the underlying self-cleaning mechanisms, the methods are classified into two categories: self-cleaning with water and without water. The review gives a succinct account of the detailed mechanisms and biomimetic processes applied to create artificial self-cleaning materials and surfaces, and provides some examples of cutting-edge applications such as anti-reflection, water repellence, self-healing, anti-fogging and micro-manipulators. The prospectives and directions of future development are also briefly proposed.

  20. Biomimetic self-cleaning surfaces: synthesis, mechanism and applications.

    Science.gov (United States)

    Xu, Quan; Zhang, Wenwen; Dong, Chenbo; Sreeprasad, Theruvakkattil Sreenivasan; Xia, Zhenhai

    2016-09-01

    With millions of years of natural evolution, organisms have achieved sophisticated structures, patterns or textures with complex, spontaneous multifunctionality. Among all the fascinating characteristics observed in biosystems, self-cleaning ability is regarded as one of the most interesting topics in biomimicry because of its potential applications in various fields such as aerospace, energy conversion and biomedical and environmental protection. Recently, in-depth studies have been carried out on various compelling biostructures including lotus leaves, shark skins, butterfly wings and gecko feet. To understand and mimic their self-cleaning mechanisms in artificial structures, in this article, recent progress in self-cleaning techniques is discussed and summarized. Based on the underlying self-cleaning mechanisms, the methods are classified into two categories: self-cleaning with water and without water. The review gives a succinct account of the detailed mechanisms and biomimetic processes applied to create artificial self-cleaning materials and surfaces, and provides some examples of cutting-edge applications such as anti-reflection, water repellence, self-healing, anti-fogging and micro-manipulators. The prospectives and directions of future development are also briefly proposed. PMID:27628170

  1. Graphitic design: prospects of graphene-based nanocomposites for solar energy conversion, storage, and sensing.

    Science.gov (United States)

    Lightcap, Ian V; Kamat, Prashant V

    2013-10-15

    Graphene not only possesses interesting electrochemical behavior but also has a remarkable surface area and mechanical strength and is naturally abundant, all advantageous properties for the design of tailored composite materials. Graphene-semiconductor or -metal nanoparticle composites have the potential to function as efficient, multifunctional materials for energy conversion and storage. These next-generation composite systems could possess the capability to integrate conversion and storage of solar energy, detection, and selective destruction of trace environmental contaminants or achieve single-substrate, multistep heterogeneous catalysis. These advanced materials may soon become a reality, based on encouraging results in the key areas of energy conversion and sensing using graphene oxide as a support structure. Through recent advances, chemists can now integrate such processes on a single substrate while using synthetic designs that combine simplicity with a high degree of structural and composition selectivity. This progress represents the beginning of a transformative movement leveraging the advancements of single-purpose chemistry toward the creation of composites designed to address whole-process applications. The promising field of graphene nanocomposites for sensing and energy applications is based on fundamental studies that explain the electronic interactions between semiconductor or metal nanoparticles and graphene. In particular, reduced graphene oxide is a suitable composite substrate because of its two-dimensional structure, outstanding surface area, and electrical conductivity. In this Account, we describe common assembly methods for graphene composite materials and examine key studies that characterize its excited state interactions. We also discuss strategies to develop graphene composites and control electron capture and transport through the 2D carbon network. In addition, we provide a brief overview of advances in sensing, energy conversion

  2. Influences of external factors on the energy conversion and productivity of Scenedesmus sp. in mass culture

    NARCIS (Netherlands)

    Wesselius, J.C.

    1973-01-01

    Experiments about the influence of external factors on the energy conversion in mass cultures of Scenedesmus are described in this thesis. Several types of culture vessels were used in the laboratory as well as in the open. Demonstration models of Miele washing machines with a volume of 50 l were us

  3. Prospective framework for collection and exploitation of waste cooking oil as feedstock for energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Singhabhandhu, Ampaitepin; Tezuka, Tetsuo [Energy Economics Laboratory, Department of Socio-Environmental Energy Science, Graduate School of Energy Science, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)

    2010-04-15

    From the viewpoint of waste-to-energy, waste cooking oil is one of the attractive and available recycled feedstocks, apart from agricultural residues. The generation of energy from waste cooking oil is considered as an effective technique for waste management, as well as a beneficial form of energy recovery. Two alternative systems and a conventional system of waste cooking oil collection and conversion are evaluated by the cost benefit analysis in order to find a suitable method for waste-to-energy conversion. The results show that the collection of waste cooking oil with waste lubricating oil (System II) a useful alternative to the management of waste cooking oil (B/C > 1). The total heat produced by the combustion of pyrolytic oil at maximum and minimum conversion rates is also determined. The separate collection of waste cooking oil, subjected to chemical pre-treatment prior to introduction in a pyrolysis reactor (System III), is considered an undesirable option (B/C < 1) due to the cost of the chemicals involved. Although the exclusion of chemical pre-treatment makes System III a desirable option, the total amount of heat of combustion generated is less. The increased electricity cost required for the process has no effect on the benefit-cost ratio of System II. However, System III, excluding chemical pre-treatment, becomes an unprofitable alternative when the electricity cost reaches 100% of the fixed capital cost at the minimum conversion rate. (author)

  4. Using Articulate Virtual Laboratories in Teaching Energy Conversion at the U.S. Naval Academy.

    Science.gov (United States)

    Wu, C.

    1998-01-01

    The Mechanical Engineering Department at the U.S. Naval Academy is currently evaluating a new teaching method which uses computer software. Utilizing the thermodynamic-based software CyclePad, Intelligent Computer Aided Instruction is incorporated in an advanced energy conversion course for Mechanical Engineering students. The CyclePad software…

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    The Voltage Source Converters (VSCs) are often connected in parallel in a Wind Energy Conversion System (WECS) to match the high power rating of the modern wind turbines. The effect of the interleaved carriers on the harmonic performance of the parallel connected VSCs is analyzed in this paper. I...

  6. Efficiency enhancement of stationary solar energy based power conversion systems in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Sharan, Anand M. [Faculty of Engineering, Memorial University of Newfoundland, St. John' s, Newfoundland (Canada)

    2009-09-15

    This paper presents the optimum energy conversion conditions of stationary photovoltaic panels used for electrical power generation. The results are arrived at after performing calculations for 180 days in a given year at the latitude of St. John's, Newfoundland. The latitude of this city is close to other Canadian major population centers. Various angular orientations of sun's rays on the earth are considered. On a given day, the incident energy flux of sun is resolved into three components, and the conversion efficiency is based on the flux normal to the panels. The efficiency of conversion of the incident energy is measured with respect to a solar tracking process. The numbers of days in a given year are divided into two groups - one between the winter solstice and the spring equinox, and another between the spring equinox and the summer solstice. The results show the existence of two maxima, one for each of the two periods. By setting the panels at each of these maxima, very significant improvement in energy conversion can be achieved. (author)

  7. Conversion and conservation of light energy in a photosynthetic microbial mat ecosystem

    DEFF Research Database (Denmark)

    Al-Najjar, A. A.; de Beer, Dirk; Jørgensen, Bo Barker;

    2010-01-01

    approach uses microscale measurements of the rates of heat dissipation, gross photosynthesis and light absorption in the system, and a model describing light propagation and conversion in a scattering-absorbing medium. The energy budget was dominated by heat dissipation on the expense of photosynthesis...

  8. Patchy zooplankton grazing and high energy conversion efficiency: ecological implications of sandeel behavior and strategy

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Christensen, Asbjørn; Rindorf, Anna

    2013-01-01

    of prey. Here we studied zooplankton consumption and energy conversion efficiency of lesser sandeel (Ammodytes marinus) in the central North Sea, using stomach data, length and weight-at-age data, bioenergetics, and hydrodynamic modeling. The results suggested: (i) Lesser sandeel in the Dogger area depend...... sandeel densities and growth rates per area than larger habitats...

  9. Evaluation of Switch Currents in Nine-Switch Energy Conversion Systems

    DEFF Research Database (Denmark)

    Loh, Poh Chiang; Bahman, Amir Sajjad; Qin, Zian;

    2013-01-01

    since been shown to experience a higher voltage stress, which can be lowered in some cases. A corresponding evaluation of its current stress is however lacking, and is hence addressed now by computing its switch currents when used for ac-ac, ac-dc, dc-ac and dc-dc energy conversions. Relevant...

  10. Evaluation of current stresses in nine-switch energy conversion systems

    DEFF Research Database (Denmark)

    Qin, Zian; Loh, Poh Chiang; Bahman, Amir Sajjad;

    2014-01-01

    since been shown to experience a higher voltage stress, which can be lowered in some cases. A corresponding evaluation of its current stress is however lacking, and is hence addressed now by computing its switch currents when used for ac-ac, ac-dc, dc-ac and dc-dc energy conversions. Relevant...

  11. Energy conversion behind overfall weirs with a free overfall jet; Energieumwandlung hinter Ueberfallwehren mit freiem Ueberfallstrahl

    Energy Technology Data Exchange (ETDEWEB)

    Heimann, Stefan; Welzel, Mario [Beuth Hochschule fuer Technik Berlin (Germany). Fachbereich III: Bauingenieur- und Geoinformationswesen

    2012-07-01

    Design criteria for the dimensioning of a stilling basin and river bed are developed by means of an investigation of the energy conversion behind an overfall weir with a fish-bellied damper. The authors of the contribution under consideration report on the main results of this investigation.

  12. Loss comparison of different nine-switch and twelve-switch energy conversion systems

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Loh, Poh Chiang; Qin, Zian;

    2014-01-01

    answer only available after performing a thorough analysis. For that, it is the intention now to compare the nine-switch and twelve-switch converters when they are used in ac-ac, ac-dc, dc-ac or dc-dc energy conversion systems. Their losses will be compared to identify when the nine-switch converter will...

  13. Compilation of Failure Data and Fault Tree Analysis for Geothermal Energy Conversion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, F.L., Jr.; Zimmerman, D.E.

    1990-11-01

    The failure data for geothermal energy conversion facilities collected to date are compiled and tabled. These facilities have not accumulated sufficient production history to reliably estimated component failure rates. In addition, the improvements made in drilling technology in recent years may have made less pertinent the accumulation of data on well failures.

  14. Workshop proceedings: Photovoltaic conversion of solar energy for terrestrial applications. Volume 2: Invited papers

    Science.gov (United States)

    1973-01-01

    A photovoltaic device development plan is reported that considers technological as well as economical aspects of single crystal silicon, polycrystal silicon, cadmium sulfide/copper sulfide thin films, as well as other materials and devices for solar cell energy conversion systems.

  15. Future thrusts of the NASA space power program. [with emphasis on electrochemical energy conversion and storage

    Science.gov (United States)

    Holcomb, L.

    1978-01-01

    General objectives and plan directions are given for current program support in the following areas: (1) solar cells and arrays; (2) batteries and fuel cells; (3) thermoelectric, thermionic, and Brayton cycle conversion systems; (4) circuits and subsystems for the management and distribution of power; and (5) the interactions of the environment with the power system and the spacecraft. Particular emphasis is given to the electrochemical energy conversion storage portion of the program where efforts are directed to improving the energy density and life of nickel cadmium batteries, to validating flight-weight silver hydrogen cells, to promoting the safe use of lithium primary batteries, to completing the silver zinc batteries and the orbital transfer fuel cell technology, to increasing the capacity of space batteries, to and to evaluating new electrochemical concepts for very high energy density. The use of the fuel cell electrolyzer concept for energy storage in both the dedicated and the truly regenerative mode is also being investigated.

  16. Wind Sensorless Control of Wind Energy Conversion System with PMS Generator

    OpenAIRE

    El Magri, Abdelmounime; Giri, Fouad; Elfadili, Abderrahim; Dugard, Luc

    2012-01-01

    6 pages; International audience; This paper addresses the problem of controlling wind energy conversion systems (WECS) which involve permanent magnet synchronous generator (PMSG) fed by IGBT-based buck-to-buck rectifier-inverter. The goal of control is to maximize wind energy extraction and this needs letting the wind turbine rotor operate in variable-speed mode. Interestingly, the present study features the achievement of the above energetic goal without resorting to sensors for wind velocit...

  17. International conference on the photochemical conversion and storage of solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Hofman, M.Z.

    1977-01-31

    Abstracts are given for the eight formal lectures and the contributed papers from delegates which were presented in the form of posters. There were seven sessions divided by subject as follows: (1) photochemistry, (2) electron transfer mechanisms in photochemical energy conversion processes, (3) photoelectrolysis, (4) photogalvanics, (5) photochemical production of fuels in homogeneous solutions, (6) membranes for photosynthesis reactions, and (7) non-biological systems for organic molecular energy storage. (WHK)

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

    CERN Document Server

    Karady, George G

    2013-01-01

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

  19. Symmetry, vibrational energy redistribution and vibronic coupling: The internal conversion processes of cycloketones

    OpenAIRE

    Kuhlman, Thomas Scheby; Sauer, Stephan P. A.; Sølling, Theis I.; Møller, Klaus Braagaard

    2012-01-01

    In this paper, we discern two basic mechanisms of internal conversion processes; one direct, where immediate activation of coupling modes leads to fast population transfer and one indirect, where internal vibrational energy redistribution leads to equidistribution of energy, i.e., ergodicity, and slower population transfer follows. Using model vibronic coupling Hamiltonians parameterized on the basis of coupled-cluster calculations, we investigate the nature of the Rydberg to valence excited-...

  20. Thermal-to-electrical energy conversion by diodes under negative illumination

    Science.gov (United States)

    Santhanam, Parthiban; Fan, Shanhui

    2016-04-01

    We consider an infrared photodiode under negative illumination, wherein the photodiode is maintained at a temperature T and radiatively exposed to an emissive body colder than itself. We experimentally demonstrate that a diode under such conditions can generate electrical power. We show theoretically that the efficiency of energy conversion can approach the Carnot limit. This work is applicable to waste heat recovery as well as emerging efforts to utilize the cold dark universe as a thermodynamic resource for renewable energy.

  1. InGaAsP/InP intrastep quantum wells for enhanced solar energy conversion

    OpenAIRE

    Chen, Winnie Victoria

    2012-01-01

    This dissertation explores innovative ways of improving efficiency of solar energy harvesting devices and evaluates them both analytically and experimentally. Two devices of different energy-harvesting mechanisms are presented : (1) intra-step quantum well (IQW) photovoltaic solar cell and (2) solar spectral condenser with IQWs. The IQW structure, step-like Type 1 (straddling gap) heterojunction structure, is used in both devices in order to help increase the conversion efficiency from solar ...

  2. Effect of Agricultural Feedstock to Energy Conversion Rate on Bioenergy and GHG Emissions

    Directory of Open Access Journals (Sweden)

    Chih-Chun Kung

    2015-05-01

    Full Text Available Taiwan is eager to develop renewable energy because it is vulnerable to energy price distortion and ocean level rise. Previous studies show bioenergy technologies can be applied mutually, but pay little attention on feedstocks to energy conversion rate, which has potential influences on policy making in renewable energy and environment. This study employs a price endogenous mathematical programming model to simultaneously simulate the market operations under various feedstocks to energy conversion rates, energy prices, and greenhouse gas (GHG prices. The result shows pyrolysis-based electricity can reach up to 2.75 billion kWh annually, but it will be driven out at low conversion rate and high GHG price. Pyrolysis plus biochar application will be the optimal option in terms of carbon sequestration. Market valuation on potential threats of extreme weather could have substantial influences on ethanol and renewable electricity generation. To achieve aimed GHG emission reduction and/or bioenergy production, government intervention may be involved to align the market operation with Taiwan’s environmental policy.

  3. Transition metal based layered double hydroxides tailored for energy conversion and storage

    Directory of Open Access Journals (Sweden)

    Xia Long

    2016-05-01

    Full Text Available Layered double hydroxides (LDHs are a class of clays with brucite like layers and intercalated anions. The first (3d series transition metals based LDHs (TM-LDHs are attracting increasing interest in the field of energy conversion and storage processes due to their unique physicochemical properties. In this article, we review recent developments in the synthesis and applications of TM-LDH in these areas including water splitting, CO2 conversion, metal-air batteries and supercapacitors and the underlying mechanisms of these processes. In addition, current challenges and possible strategies are discussed from the viewpoint of material design and performance.

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

    International Nuclear Information System (INIS)

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

  5. N-losses and energy use in a scenario for conversion to organic farming

    DEFF Research Database (Denmark)

    Dalgaard, Tommy; Kjeldsen, Chris; Hutchings, Nick;

    2002-01-01

    is not straightforward, and different scenarios for conversion to organic farming might lead to reduced or increased N-losses and E-use. This paper presents a scenario tool that uses a Geographical Information System in association with models for crop rotations, fertilisation practices, N-losses, and E...... reduction at the 95% level. We therefore recommend further research in how conversion to organic farming or other changes in the agricultural practice might help to reduce N-surpluses and E-uses. In that context, the presented scenario tool would be useful......The aims of organic farming include the recycling of nutrients and organic matter and the minimisation of the environmental impact of agriculture. Reduced nitrogen (N)-losses and energy (E)-use are therefore fundamental objectives of conversion to organic farming. However, the case...

  6. Excited state energies and internal conversion in diphenylpolyenes: from diphenylbutadiene to diphenyltetradecaheptaene

    Science.gov (United States)

    Bachilo, S. M.; Spangler, C. W.; Gillbro, T.

    1998-02-01

    Time-resolved and steady-state fluorescence investigations on a series of α,ω-diphenylpolyenes have been made. Dual S 1/S 2 fluorescence was observed for polyenes with more than three double bonds in the polyene chain and the intensity and lifetime of the S 1 fluorescence decreased with increasing chain length. The 1B u energy was almost inversely proportional to the square root of the total molecular length. A similar dependence was found for the energy of the 1A g level, but the length without the phenyl rings was used. The logarithm of the S 1→S 0 internal conversion rate in long-chain diphenylpolyenes exhibits a linear dependence on the S 1 energy. The rate in diphenylhexatriene is slightly higher than the value predicted from the linear dependence, while the internal conversion of diphenylbutadiene is much faster due to stronger S 1-S 2 interaction.

  7. Electrokinetic Energy Conversion in Nanofluidic Channels: Addressing the Loose Ends in Nanodevice Efficiency

    CERN Document Server

    Bakli, Chirodeep

    2014-01-01

    We bring out a non-trivial coupling of the intrinsic wettability, surface charge and electrokinetic energy conversion characteristics of nanofluidic devices. Our analyses demonstrate that nanofluidic energy conversion efficiencies may get amplified with increase in surface charge density, not perpetually, but only over a narrow regime of low surface charges, and may get significantly arrested to reach a plateau beyond a threshold surface charging condition, as attributed to a complex interplay between fluid structuration and ionic transport within a charged interfacial layer. We explain the corresponding findings from our molecular dynamics simulations with the aid of a simple modified continuum based theory. We attribute our findings to hitherto-unexplored four-way integration of surface charge, interfacial slip, ionic transport, and the water molecule structuration. The consequent complex non-linear nature of the energy transfer characteristics may bear far-ranging scientific and technological implications ...

  8. Grid Connected Wind Energy Conversion System Using Three Phase Matrix Converter

    Directory of Open Access Journals (Sweden)

    R.A. Priya

    2015-01-01

    Full Text Available A variable speed Wind Energy Conversion System (WECS with Permanent Magnet Synchronous Generator (PMSG connected to grid through Matrix Converter (MC is proposed in this study. Necessity for increased demand in electrical energy paved way for use of renewable energy sources, one of which is abundant wind energy available in ample. Various Wind Energy Conversion systems have been proposed over the decades, of which various topologies had been projected, where complex topologies are being in existence. Permanent magnet synchronous generator has substantial advantages over conventional generators like less weight and volume and exemption for separate excitation with high precision. The conventional system involves two stage of conversion involving rectification followed by inversion being coupled by a DC link capacitor before fed to a grid, which decreases the efficiency of the system due to power quality issue. To overcome this matrix converter can be utilized to transfer the power from generation stage to the grid; there by an AC-AC converter can transfer power from generator to the grid. The proposed system is designed and tested in MATALB/Simulink environment and the results are effective.

  9. Ocean Current Energy Conversion System in Wallacea Region Using Variable Speed Control Approach

    Directory of Open Access Journals (Sweden)

    Aditya Sukma Nugraha

    2012-03-01

    Full Text Available Ocean Current Energy Conversion System (OCECS is a promising green energy resource in this globe. The Thermohaline circulation data indicates that the Wallacea region has the potential of ocean current energy resources. This paper is aimed to propose research and development of OCECSs to be implemented in the Wallacea region. Firstly, four types of green energy conversion systems extracted from ocean are reviewed. Their advantages and disadvantages are discussed. Secondly, the potential of OCECS in the Wallacea region is described. Third, many types of turbines used for OCECS are reviewed and the turbine type for OCECS is selected to be implemented in the Wallacea region. Fourth, control strategy is proposed.From the work reported in this paper it is concluded that it is appropriate to implement OCECSs using axial flow water turbines in the Wallacea region, and that to maximize energy conversion variable speed control approach is selected together with control of mechanism to move the turbine vertically as well as to rotate the turbine in yaw direction. 

  10. High energy conversion efficiency in laser-proton acceleration by controlling laser-energy deposition onto thin foil targets

    Energy Technology Data Exchange (ETDEWEB)

    Brenner, C. M. [Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Central Laser Facility, STFC, Rutherford Appleton Laboratory, Didcot, Oxon OX11 0QX (United Kingdom); Robinson, A. P. L.; Markey, K.; Scott, R. H. H.; Lancaster, K. L.; Musgrave, I. O.; Spindloe, C.; Winstone, T.; Wyatt, D.; Neely, D. [Central Laser Facility, STFC, Rutherford Appleton Laboratory, Didcot, Oxon OX11 0QX (United Kingdom); Gray, R. J.; McKenna, P. [Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Rosinski, M.; Badziak, J.; Wolowski, J. [Institute of Plasma Physics and Laser Microfusion, 00-908 Warsaw (Poland); Deppert, O. [Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt (Germany); Batani, D. [Dipartimento di Fisica G. Occhialini, Universita di Milano Bicocca, 20126 Milan (Italy); Davies, J. R. [Laboratory for Laser Energetics, Fusion Science Center for Extreme States of Matter, University of Rochester, Rochester, New York 14623 (United States); Hassan, S. M.; Tatarakis, M. [Department of Electronics Engineering, Centre for Plasma Physics and Lasers, 73133 Chania, 74100 Rethymno, Crete (Greece); and others

    2014-02-24

    An all-optical approach to laser-proton acceleration enhancement is investigated using the simplest of target designs to demonstrate application-relevant levels of energy conversion efficiency between laser and protons. Controlled deposition of laser energy, in the form of a double-pulse temporal envelope, is investigated in combination with thin foil targets in which recirculation of laser-accelerated electrons can lead to optimal conditions for coupling laser drive energy into the proton beam. This approach is shown to deliver a substantial enhancement in the coupling of laser energy to 5–30 MeV protons, compared to single pulse irradiation, reaching a record high 15% conversion efficiency with a temporal separation of 1 ps between the two pulses and a 5 μm-thick Au foil. A 1D simulation code is used to support and explain the origin of the observation of an optimum pulse separation of ∼1 ps.

  11. The exergy of thermal radiation and its relevance in solar energy conversion

    Science.gov (United States)

    Wright, Sean Edward

    Driven by the importance of optimizing energy systems and technologies, the field of exergy analysis was developed to better illuminate process inefficiencies and evaluate performance. Exergy analysis provides important information and understanding that cannot be obtained from energy analysis. The field of exergy analysis is well formulated and understood except for thermal radiation (TR) heat transfer. The exergy flux, or maximum work obtainable, from TR has not been unambiguously determined. Moreover, many thermodynamic textbooks are misleading by incorrectly implying that the entropy and exergy transport with TR is calculated by using the same expressions that apply to heat conduction. Research on the exergy of TR was carried out by Petela. However, many researchers have considered Petela's analysis of the exergy of TR to be irrelevant to the conversion of TR fluxes. Petela's thermodynamic approach is considered irrelevant because, others argue, that it neglects fundamental issues that are specific to the conversion of fluxes, issues that are unusual in the context of exergy analysis. The purpose of the research in this thesis is to determine, using fundamental thermodynamic principles, the exergy flux of TR with an arbitrary spectrum and its relevance to solar radiation (SR) conversion. In this thesis it is shown that Petela's result can be used for the exergy flux of blackbody radiation (BR) and represents the upper limit to the conversion of SR approximated as BR. The thesis shows this by resolving a number of fundamental issues: (1)Inherent Irreversibility; (2)Definition of the Environment; (3)Inherent Emission; (4)Threshold Behaviour; (5)Effect of Concentrating TR. This thesis also provides a new expression, based on inherent irreversibility, for the exergy flux of TR with an arbitrary spectrum. Previous analysis by Karlsson assumes that reversible conversion of non-blackbody radiation (NBR) is theoretically possible, whereas this thesis presents evidence

  12. [Biomimetic sensors in biomedical research].

    Science.gov (United States)

    Gayet, Landry; Lenormand, Jean-Luc

    2015-01-01

    The recent research on both the synthesis of membrane proteins by cell-free systems and the reconstruction of planar lipid membranes, has led to the development of a cross-technology to produce biosensors or filters. Numerous biomimetic membranes are currently being standardized and used by the industry, such as filters containing aquaporin for water desalination, or used in routine at the laboratory scale, for example the bacteriorhodopsin as a light sensor. In the medical area, several fields of application of these biomimetic membranes are under consideration today, particularly for the screening of therapeutic molecules and for the developing of new tools in diagnosis, patient monitoring and personalized medicine. PMID:26152170

  13. Solar energy conversion systems engineering and economic analysis radiative energy input/thermal electric output computation. Volume III

    Energy Technology Data Exchange (ETDEWEB)

    Russo, G.

    1982-09-01

    The direct energy flux analytical model, an analysis of the results, and a brief description of a non-steady state model of a thermal solar energy conversion system implemented on a code, SIRR2, as well as the coupling of CIRR2 which computes global solar flux on a collector and SIRR2 are presented. It is shown how the CIRR2 and, mainly, the SIRR2 codes may be used for a proper design of a solar collector system. (LEW)

  14. Advancing the Frontiers in Nanocatalysis, Biointerfaces, and Renewable Energy Conversion by Innovations of Surface Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, G.A.; Frei, H.; Park, J.Y.

    2009-07-23

    The challenge of chemistry in the 21st century is to achieve 100% selectivity of the desired product molecule in multipath reactions ('green chemistry') and develop renewable energy based processes. Surface chemistry and catalysis play key roles in this enterprise. Development of in situ surface techniques such as high-pressure scanning tunneling microscopy, sum frequency generation (SFG) vibrational spectroscopy, time-resolved Fourier transform infrared methods, and ambient pressure X-ray photoelectron spectroscopy enabled the rapid advancement of three fields: nanocatalysts, biointerfaces, and renewable energy conversion chemistry. In materials nanoscience, synthetic methods have been developed to produce monodisperse metal and oxide nanoparticles (NPs) in the 0.8-10 nm range with controlled shape, oxidation states, and composition; these NPs can be used as selective catalysts since chemical selectivity appears to be dependent on all of these experimental parameters. New spectroscopic and microscopic techniques have been developed that operate under reaction conditions and reveal the dynamic change of molecular structure of catalysts and adsorbed molecules as the reactions proceed with changes in reaction intermediates, catalyst composition, and oxidation states. SFG vibrational spectroscopy detects amino acids, peptides, and proteins adsorbed at hydrophobic and hydrophilic interfaces and monitors the change of surface structure and interactions with coadsorbed water. Exothermic reactions and photons generate hot electrons in metal NPs that may be utilized in chemical energy conversion. The photosplitting of water and carbon dioxide, an important research direction in renewable energy conversion, is discussed.

  15. Water-related environmental control requirements at municipal solid waste-to-energy conversion facilities

    Energy Technology Data Exchange (ETDEWEB)

    Young, J C; Johnson, L D

    1980-09-01

    Water use and waste water production, water pollution control technology requirements, and water-related limitations to their design and commercialization are identified at municipal solid waste-to-energy conversion systems. In Part I, a summary of conclusions and recommendations provides concise statements of findings relative to water management and waste water treatment of each of four municipal solid waste-to-energy conversion categories investigated. These include: mass burning, with direct production of steam for use as a supplemental energy source; mechanical processing to produce a refuse-derived fuel (RDF) for co-firing in gas, coal or oil-fired power plants; pyrolysis for production of a burnable oil or gas; and biological conversion of organic wastes to methane. Part II contains a brief description of each waste-to-energy facility visited during the subject survey showing points of water use and wastewater production. One or more facilities of each type were selected for sampling of waste waters and follow-up tests to determine requirements for water-related environmental controls. A comprehensive summary of the results are presented. (MCW)

  16. Progress in the technology of energy conversion from woody biomass in Indonesia

    Institute of Scientific and Technical Information of China (English)

    Tjutju Nurhayati; Yani Waridi; Han Roliadi

    2006-01-01

    Sustainable and renewable natural resources as biomass that contains carbon and hydrogen elements can be a potential raw materials for energy conversion. In Indonesia, they comprise variable-sized wood from forests (i.e. natural forests, plantations and community forests that commonly produce small-diameter logs used as firewood by local people), woody residues from logging and wood industries, oil-palm shell waste from crude palm oil factories, coconut shell wastes from coconut plantations, traditional markets as well as skimmed coconut oil and straws from rice cultivation.Four kinds of energy-conversion technologies have been empirically tested in Indonesia. First, gasification of rubber wood from unproductive rubber trees to generate heat energy for the drying of fermented chocolate seeds. Secondly, energy conversion from organic vegetable waste by implementing thermophylic fermentation methods that produce biogas as a fuel and for generating electricity and also concurrently generate organic by-products called hygen compost. Thirdly, gasification of charcoal and wood sawdust for electricity generation. Finally, environment-friendly energy conversion by carbonizing small-diameter logs, sawdust, wood slabs and coconut shells into charcoal. This yielded charcoal integrated with wood vinegar production through condensation of smoke/vapors emitted during carbonization, thereby mitigating the impact of air pollution. Among the four experimental technologies that of integrated charcoal and wood vinegar production had been spectacularly developed and favored by rural communities. This technology brought added value to the process and product due to the wood vinegar,useful as bio-pesticide,plant-growth hormone and organic fertilizer. Such integrated and environment-friendly production, therefore,should be sustained, because Indonesia occupies a significant and worldwide position as charcoal-producing and marketing country.The technology of integrated wood vinegar

  17. Effects of canopy interception on energy conversion processes in a Chinese fir plantation ecosystem

    Institute of Scientific and Technical Information of China (English)

    Wenxing KANG; Xiangwen DENG; Zhonghui ZHAO

    2008-01-01

    The functions of canopy interception on energy conversion processes in a Chinese fir plantation ecosystem were studied with the aid of long-term obser-vation data in Huitong. The results showed that the absorbed, penetrated and reflected amounts of solar (reflection rate of 0.091) by the canopy. The conversion of net solar radiation to latent heat in the process of evap-oration from canopy interception amounted to ecosystem net radiation and 30.4% of ecosystem evapora-tion), which was an important part of the budget of the energy system. Canopy interception consumed kinetic energy of raindrops in overcoming resistance of branches and leaves, which collected raindrops, followed with the conversion of potential energy in raindrops to kinetic energy with falling raindrops. In general, the diameter of raindrops from the canopy is larger than that of the rain-drops above the canopy as a result of the collection effort by the canopy. The kinetic energy of raindrops from the canopy, therefore, was higher than that of raindrops in the atmosphere. The drop-size distribution from the canopy was affected by the structure of the canopy layer rather than the amount of precipitation and precipitation intens-ity. The canopy had no important nor efficient effects on decreasing the kinetic energy of raindrops in our case study with a first branch height of 7 m and precipitation amounts over 3 ram. However, the canopy would play a key role in decreasing kinetic energy of raindrops in two cases, that of a small amount of precipitation and one of heavy precipitation intensity, in which the canopy could intercept the largest amount of precipitation in the former condition and the canopy could scatter bigger raindrops to smaller raindrops with striking leaves in the case of heavy precipitation.

  18. Clean energy systems in the subsurface. Production, storage and conversion. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Zhengmeng Michael; Were, Patrick (eds.) [Clausthal Univ. of Technology, Goslar (Germany). Energie-Forschungszentrum Niedersachsen (EFZN); Xie, Heping [Sichuan Univ., Chengdu (China)

    2013-04-01

    Recent research on Integrated Energy and Environmental Utilization of Deep Underground Space. Results of the 3{sup rd} Sino-German Conference ''Underground Storage of CO{sub 2} and Energy'', held at Goslar, Germany, 21-23 May 2013. Researchers and professionals from academia and industry discuss the future of deep underground space technologies for an integrated energy and environmental utilization. Anthropogenic greenhouse gas emissions, energy security and sustainability are three of the greatest contemporary global challenges today. This year the Sino-German Cooperation Group ''Underground Storage of CO{sub 2} and Energy'', is meeting on the 21-23 May 2013 for the second time in Goslar, Germany, to convene its 3{sup rd} Sino-German conference on the theme ''Clean Energy Systems in the Subsurface: Production, Storage and Conversion''.

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

    Science.gov (United States)

    Boona, Stephen R.; Watzman, Sarah J.; Heremans, Joseph P.

    2016-10-01

    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.

  20. Performance and economics of advanced energy conversion systems for coal and coal-derived fuels

    Science.gov (United States)

    Corman, J. C.; Fox, G. R.

    1978-01-01

    The desire to establish an efficient Energy Conversion System to utilize the fossil fuel of the future - coal - has produced many candidate systems. A comparative technical/economic evaluation was performed on the seven most attractive advanced energy conversion systems. The evaluation maintains a cycle-to-cycle consistency in both performance and economic projections. The technical information base can be employed to make program decisions regarding the most attractive concept. A reference steam power plant was analyzed to the same detail and, under the same ground rules, was used as a comparison base. The power plants were all designed to utilize coal or coal-derived fuels and were targeted to meet an environmental standard. The systems evaluated were two advanced steam systems, a potassium topping cycle, a closed cycle helium system, two open cycle gas turbine combined cycles, and an open cycle MHD system.

  1. Determination of the nuclear induced electrical conductivity of 3He for magnetohydrodynamic energy conversion

    International Nuclear Information System (INIS)

    This is the final report for a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The continual need for more efficient, high-output energy conversion techniques has renewed interest in nuclear-driven magnetohydrodynamic (MHD) energy conversion. To provide the fundamental knowledge required to evaluate the potential value of this concept, a one-year project aimed at measuring the nuclear-induced electrical conductivity of a 3He/4He gas mixture under thermodynamic conditions consistent with the MHD flow conditions was carried out. The range of bulk gas conditions to be considered were: pressure = 0.1 to 3800 Torr and temperature = 300 to 1500 K. The maximum neutron flux to be considered was 1016/cm2sec. The range of parameters considered surpassed previous experiments in all aspects

  2. Layered double hydroxides toward electrochemical energy storage and conversion: design, synthesis and applications.

    Science.gov (United States)

    Shao, Mingfei; Zhang, Ruikang; Li, Zhenhua; Wei, Min; Evans, David G; Duan, Xue

    2015-11-14

    Two-dimensional (2D) materials have attracted increasing interest in electrochemical energy storage and conversion. As typical 2D materials, layered double hydroxides (LDHs) display large potential in this area due to the facile tunability of their composition, structure and morphology. Various preparation strategies, including in situ growth, electrodeposition and layer-by-layer (LBL) assembly, have been developed to directly modify electrodes by using LDH materials. Moreover, several composite materials based on LDHs and conductive matrices have also been rationally designed and employed in supercapacitors, batteries and electrocatalysis with largely enhanced performances. This feature article summarizes the latest developments in the design, preparation and evaluation of LDH materials toward electrochemical energy storage and conversion. PMID:26459951

  3. Optimize out-of-core thermionic energy conversion for nuclear electric propulsion

    Science.gov (United States)

    Morris, J. F.

    1978-01-01

    Thermionic energy conversion (TEC) potentialities for nuclear electric propulsion (NEP) are examined. Considering current designs, their limitations, and risks raises critical questions about the use of TEC for NEP. Apparently a reactor cooled by hotter-than-1675 K heat pipes has good potentialities. TEC with higher temperatures and greater power densities than the currently proposed 1650 K, 5-to-6 W/sq cm version offers substantial gains. Other approaches to high-temperature electric isolation appear also promising. A high-power-density, high-temperature TEC for NEP appears, therefore, attainable. It is recommended to optimize out-of-core thermionic energy conversion for nuclear electric propulsion. Although current TEC designs for NEP seem unnecessary compared with Brayton versions, large gains are apparently possible with increased temperatures and greater power densities.

  4. Plasmonic hot carrier dynamics in solid-state and chemical systems for energy conversion

    Science.gov (United States)

    Narang, Prineha; Sundararaman, Ravishankar; Atwater, Harry A.

    2016-06-01

    Surface plasmons provide a pathway to efficiently absorb and confine light in metallic nanostructures, thereby bridging photonics to the nano scale. The decay of surface plasmons generates energetic `hot' carriers, which can drive chemical reactions or be injected into semiconductors for nano-scale photochemical or photovoltaic energy conversion. Novel plasmonic hot carrier devices and architectures continue to be demonstrated, but the complexity of the underlying processes make a complete microscopic understanding of all the mechanisms and design considerations for such devices extremely challenging.Here,we review the theoretical and computational efforts to understand and model plasmonic hot carrier devices.We split the problem into three steps: hot carrier generation, transport and collection, and review theoretical approaches with the appropriate level of detail for each step along with their predictions.We identify the key advances necessary to complete the microscopic mechanistic picture and facilitate the design of the next generation of devices and materials for plasmonic energy conversion.

  5. Modeling and Coordinated Control Strategy of Large Scale Grid-Connected Wind/Photovoltaic/Energy Storage Hybrid Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Lingguo Kong

    2015-01-01

    Full Text Available An AC-linked large scale wind/photovoltaic (PV/energy storage (ES hybrid energy conversion system for grid-connected application was proposed in this paper. Wind energy conversion system (WECS and PV generation system are the primary power sources of the hybrid system. The ES system, including battery and fuel cell (FC, is used as a backup and a power regulation unit to ensure continuous power supply and to take care of the intermittent nature of wind and photovoltaic resources. Static synchronous compensator (STATCOM is employed to support the AC-linked bus voltage and improve low voltage ride through (LVRT capability of the proposed system. An overall power coordinated control strategy is designed to manage real-power and reactive-power flows among the different energy sources, the storage unit, and the STATCOM system in the hybrid system. A simulation case study carried out on Western System Coordinating Council (WSCC 3-machine 9-bus test system for the large scale hybrid energy conversion system has been developed using the DIgSILENT/Power Factory software platform. The hybrid system performance under different scenarios has been verified by simulation studies using practical load demand profiles and real weather data.

  6. Engineering photosynthetic light capture: impacts on improved solar energy to biomass conversion

    OpenAIRE

    Mussgnug, Jan H.; Thomas-Hall, Skye; Rupprecht, Jens; Foo, Alexander; Klassen, Viktor; McDowall, Alasdair; Schenk, Peer M.; Kruse, Olaf; Hankamer, Ben

    2007-01-01

    The main function of the photosynthetic process is to capture solar energy and to store it in the form of chemical 'fuels'. Increasingly, the photosynthetic machinery is being used for the production of biofuels such as bio-ethanol, biodiesel and bio-H-2. Fuel production efficiency is directly dependent on the solar photon capture and conversion efficiency of the system. Green algae (e.g. Chlamydomonas reinhardtii) have evolved genetic strategies to assemble large light-harvesting antenna com...

  7. Low power wind energy conversion system based on variable speed permanent magnet synchronous generators

    OpenAIRE

    Carranza Castillo, Oscar; Garcerá Sanfeliú, Gabriel; Figueres Amorós, Emilio; GONZÁLEZ MORALES, LUIS GERARDO

    2014-01-01

    This paper presents a low power wind energy conversion system (WECS) based on a permanent magnet synchronous generator and a high power factor (PF) rectifier. To achieve a high PF at the generator side, a power processing scheme based on a diode rectifier and a boost DC-DC converter working in discontinuous conduction mode is proposed. The proposed generator control structure is based on three cascaded control loops that regulate the generator current, the turbine speed and the amount of powe...

  8. Electronics and photonics: two sciences in the benefit of solar energy conversion

    OpenAIRE

    Girtan, M.

    2012-01-01

    This paper gives a personal global point of view on two sciences: electronics and photonics towards plasmonics and solar energy conversion. The new research directions in these two sciences are pointed out by comparison and in the perspective of future new solar devices. A parallel and the equivalence between electronics and photonics are presented. Starting from electron in electronics, photon, solitons and plasmons in photonics, electrical cables - optical fibers, plasmonic wave guides, ele...

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

    OpenAIRE

    Wei Wang; Ming Cheng; Ying Zhu; Wei Hua

    2012-01-01

    This paper proposes a novel optimal current given (OCG) maximum power point tracking (MPPT) control strategy based on the theory of power feedback and hill climb searching (HCS) for a permanent magnet direct drive wind energy conversion system (WECS). The presented strategy not only has the advantages of not needing the wind speed and wind turbine characteristics of the traditional HCS method, but it also improves the stability and accuracy of MPPT by estimating the exact loss torque. The OCG...

  10. A comparative study of nuclear technology and direct energy conversion methods for space power systems

    OpenAIRE

    Reason, Joseph P., Jr.

    1997-01-01

    Approved for public release; distribution in unlimited. The objectives of this thesis are to investigate the theory of direct energy conversion, research the development of space nuclear power systems, evaluate the status of current systems, and draw conclusions about the feasibility and merit of using nuclear power for future space missions. Development of the earliest systems began in 1955 with the Systems for Nuclear Auxiliary Power (SNAP) Program and Project Rover. A detailed review of...

  11. A modified Adaptive Wavelet PID Control Based on Reinforcement Learning for Wind Energy Conversion System Control

    OpenAIRE

    REZAZADEH, A.; SEDIGHIZADEH, M.

    2010-01-01

    Nonlinear characteristics of wind turbines and electric generators necessitate complicated and nonlinear control of grid connected Wind Energy Conversion Systems (WECS). This paper proposes a modified self-tuning PID control strategy, using reinforcement learning for WECS control. The controller employs Actor-Critic learning in order to tune PID parameters adaptively. These Actor-Critic learning is a special kind of reinforcement learning that uses a single wavelet neural network to appro...

  12. Recommended methods for evaluating the benefits of ECUT Program outputs. [Energy Conversion and Utilization

    Energy Technology Data Exchange (ETDEWEB)

    Levine, L.O.; Winter, C.

    1986-03-01

    This study was conducted to define and develop techniques that could be used to assess the complete spectrum of positive effects resulting from the Energy Conversion and Utilization Technologies (ECUT) Program activities. These techniques could then be applied to measure the benefits from past ECUT outputs. In addition, the impact of future ECUT outputs could be assessed as part of an ongoing monitoring process, after sufficient time has elapsed to allow their impacts to develop.

  13. On the Stator Slot Geometry of a Cable Wound Generator for Hydrokinetic Energy Conversion

    OpenAIRE

    Mårten Grabbe; Sandra Eriksson; Mats Leijon

    2015-01-01

    In this paper, the stator slot geometry of a cable wound permanent magnet synchronous generator for hydro-kinetic energy conversion is evaluated. When designing generators, practical experience is of great importance to result in a realizable design. Therefore, practical experience from winding two cable wound generators is used to propose optimized dimensions of different parts in the stator slot geometry. A thorough investigation is performed through simulations of how small geometrical cha...

  14. A Computer Program for Modeling the Conversion of Organic Waste to Energy

    OpenAIRE

    Pragasen Pillay; Rachel Namuli; Laflamme, Claude B.

    2011-01-01

    This paper presents a tool for the analysis of conversion of organic waste into energy. The tool is a program that uses waste characterization parameters and mass flow rates at each stage of the waste treatment process to predict the given products. The specific waste treatment process analysed in this paper is anaerobic digestion. The different waste treatment stages of the anaerobic digestion process are: conditioning of input waste, secondary treatment, drying of sludge, conditioning of di...

  15. Solar cooker using coatings for enhanced solar thermal energy conversion (CESTEC)

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugam, N.V.; Selvam, M.; Shenoi, B.A.; Srinivasan, K.N.; John, S.; Annamalai, M.; Iyer, M.V.; Nirmala, K.A.; Venkatesh, P.; Prasad, C.R.; Subramani, C.

    1982-01-01

    The cooker is based on the utilization of coatings for enhanced solar thermal energy conversion (CESTEC). This coating absorbs maximum fraction of the solar radiation and emit very little by reradiation and hence its temperature raises to 80 to 120/sup 0/C above the ambient and hence the food material is cooked in a shorter time in comparison to the cooker using black paint.

  16. Jet-photon conversion with energy loss in heavy ion collisions

    Institute of Scientific and Technical Information of China (English)

    ZHOU Li-Juan; ZHANG Ben-Wei; ZHANG Han-Zhong; WANG En-Ke

    2009-01-01

    The rate of high energy photons produced from energetic jets during their propagation through the QGP at RHIC and LHC is studied by taking into account the contribution of jet quenching in the medium. It is shown that the jet quenching effect reduces the rate of jet-photon conversion at large transverse momemtum by about 40% at RHIC with √S= 200 AGeV, and by about 80% at LHC with √S = 5500 AGeV.

  17. Synthesis of ceramic-based porous gradient structures for applications in energy conversion and related fields

    Science.gov (United States)

    Graule, Thomas; Ozog, Paulina; Durif, Caroline; Wilkens-Heinecke, Judit; Kata, Dariusz

    2016-06-01

    Porous, graded ceramic structures are of high relevance in the field of energy conversion as well as in catalysis, and additionally in filtration technology and in biomedical applications. Among different technologies for the tailored design for such structures we demonstrate here a new environmental friendly UV curing-based concept to prepare laminated structures with pore sizes ranging from a few microns up to 50 microns in diameter and with porosities ranging from 10% up to 75 vol.% porosity.

  18. Hybrid Intelligent Control Method to Improve the Frequency Support Capability of Wind Energy Conversion Systems

    OpenAIRE

    Shin Young Heo; Mun Kyeom Kim; Jin Woo Choi

    2015-01-01

    This paper presents a hybrid intelligent control method that enables frequency support control for permanent magnet synchronous generators (PMSGs) wind turbines. The proposed method for a wind energy conversion system (WECS) is designed to have PMSG modeling and full-scale back-to-back insulated-gate bipolar transistor (IGBT) converters comprising the machine and grid side. The controller of the machine side converter (MSC) and the grid side converter (GSC) are designed to achieve maximum pow...

  19. Characterization and modeling of electrochemical energy conversion systems by impedance techniques

    Energy Technology Data Exchange (ETDEWEB)

    Klotz, Dino

    2012-07-01

    This work introduces (i) amendments to basic electrochemical measurement techniques in the time and frequency domain suitable for electrochemical energy conversion systems like fuel cells and batteries, which enable shorter measurement times and improved precision in both measurement and parameter identification, and (ii) a modeling approach that is able to simulate a technically relevant system just by information gained through static and impedance measurements of laboratory size cells.

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

    International Nuclear Information System (INIS)

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

  1. Multi-functional electrospun nanofibres for advances in tissue regeneration, energy conversion & storage, and water treatment.

    Science.gov (United States)

    Peng, Shengjie; Jin, Guorui; Li, Linlin; Li, Kai; Srinivasan, Madhavi; Ramakrishna, Seeram; Chen, Jun

    2016-03-01

    Tissue regeneration, energy conversion & storage, and water treatment are some of the most critical challenges facing humanity in the 21st century. In order to address such challenges, one-dimensional (1D) materials are projected to play a key role in developing emerging solutions for the increasingly complex problems. Eletrospinning technology has been demonstrated to be a simple, versatile, and cost-effective method in fabricating a rich variety of materials with 1D nanostructures. These include polymers, composites, and inorganic materials with unique chemical and physical properties. In this tutorial review, we first give a brief introduction to electrospun materials with a special emphasis on the design, fabrication, and modification of 1D functional materials. Adopting the perspective of chemists and materials scientists, we then focus on the recent significant progress made in the domains of tissue regeneration (e.g., skin, nerve, heart and bone) and conversion & storage of clean energy (e.g., solar cells, fuel cells, batteries, and supercapacitors), where nanofibres have been used as active nanomaterials. Furthermore, this review's scope also includes the advances in the use of electrospun materials for the removal of heavy metal ions, organic pollutants, gas and bacteria in water treatment applications. Finally a conclusion and perspective is provided, in which we discuss the remaining challenges for 1D electrospun nanomaterials in tissue regeneration, energy conversion & storage, and water treatment. PMID:26727278

  2. Band Gap Engineering in a 2D Material for Solar-to-Chemical Energy Conversion.

    Science.gov (United States)

    Hu, Jun; Guo, Zhenkun; Mcwilliams, Peter E; Darges, John E; Druffel, Daniel L; Moran, Andrew M; Warren, Scott C

    2016-01-13

    The electronic structure of 2D semiconductors depends on their thickness, providing new opportunities to engineer semiconductors for energy conversion, electronics, and catalysis. Here we show how a 3D semiconductor, black phosphorus, becomes active for solar-to-chemical energy conversion when it is thinned to a 2D material. The increase in its band gap, from 0.3 eV (3D) to 2.1 eV (2D monolayer), is accompanied by a 40-fold enhancement in the formation of chemical products. Despite this enhancement, smaller flakes also have shorter excited state lifetimes. We deduce a mechanism in which recombination occurs at flake edges, while the "van der Waals" surface of black phosphorus bonds to chemical intermediates and facilitates electron transfer. The unique properties of black phosphorus highlight its potential as a customizable material for solar energy conversion and catalysis, while also allowing us to identify design rules for 2D photocatalysts that will enable further improvements in these materials.

  3. The Impact of Natural Hazards such as Turbulent Wind Gusts on the Wind Energy Conversion Process

    Science.gov (United States)

    Wächter, M.; Hölling, M.; Milan, P.; Morales, A.; Peinke, J.

    2012-12-01

    Wind turbines operate in the atmospheric boundary layer, where they are exposed to wind gusts and other types of natural hazards. As the response time of wind turbines is typically in the range of seconds, they are affected by the small scale intermittent properties of the turbulent wind. We show evidence that basic features which are known for small-scale homogeneous isotropic turbulence, and in particular the well-known intermittency problem, have an important impact on the wind energy conversion process. Intermittent statistics include high probabilities of extreme events which can be related to wind gusts and other types of natural hazards. As a summarizing result we find that atmospheric turbulence imposes its intermittent features on the complete wind energy conversion process. Intermittent turbulence features are not only present in atmospheric wind, but are also dominant in the loads on the turbine, i.e. rotor torque and thrust, and in the electrical power output signal. We conclude that profound knowledge of turbulent statistics and the application of suitable numerical as well as experimental methods are necessary to grasp these unique features and quantify their effects on all stages of wind energy conversion.

  4. Grid Connected Wind Energy Conversions System Performance is Improved by Switching of Shunt Active Filter

    Directory of Open Access Journals (Sweden)

    B.Vaikundaselvan

    2014-05-01

    Full Text Available This study presents a Grid connected Wind Energy Conversions System (WECS where performance is improved by switching of Shunt Active Filter. Shunt active filter for non linear loads is designed to minimize the harmonics present in the wind power system. Due to large penetration of power electronic controllers in the wind power applications, switching of these power electronic circuits induces harmonics in the source which causes undesirable effects on the wind energy conversion systems and the electrical components which is in the power system network. Shunt active filter is a harmonic mitigating device comprising of voltage source inverter fed through a DC capacitor. The control strategy is based on extraction of harmonics using synchronous reference frame theory. The major contributions of this study is to extract harmonics from the grid connected Wind Energy Conversion Systems (WECS by generating the PWM signals using the Space Vector Pulse Width Modulation (SVPWM to control the Voltage Source Inverter (VSI which has reduced the losses. The proposed method has been simulated and validated using MATLAB/SIMULINK. The end result of the proposed system shows that the Total Harmonic Distortion (THD of the grid connected wind generator has been reduced at the Point of Common Coupling (PCC.

  5. Influence of ambient air pressure on the energy conversion of laser-breakdown induced blast waves

    International Nuclear Information System (INIS)

    Influence of ambient pressure on energy conversion efficiency from a Nd : glass laser pulse (λ = 1.053 µm) to a laser-induced blast wave was investigated at reduced pressure. Temporal incident and transmission power histories were measured using sets of energy meters and photodetectors. A half-shadowgraph half-self-emission method was applied to visualize laser absorption waves. Results show that the blast energy conversion efficiency ηbw decreased monotonically with the decrease in ambient pressure. The decrease was small, from 40% to 38%, for the pressure change from 101 kPa to 50 kPa, but the decrease was considerable, to 24%, when the pressure was reduced to 30 kPa. Compared with a TEA-CO2-laser-induced blast wave (λ = 10.6 µm), higher fraction absorption in the laser supported detonation regime ηLSD of 90% was observed, which is influenced slightly by the reduction of ambient pressure. The conversion fraction ηbw/ηLSD≈90% was achieved at pressure >50 kPa, which is significantly higher than that in a CO2 laser case. (paper)

  6. Aqueous Lithium-Iodine Solar Flow Battery for the Simultaneous Conversion and Storage of Solar Energy.

    Science.gov (United States)

    Yu, Mingzhe; McCulloch, William D; Beauchamp, Damian R; Huang, Zhongjie; Ren, Xiaodi; Wu, Yiying

    2015-07-01

    Integrating both photoelectric-conversion and energy-storage functions into one device allows for the more efficient solar energy usage. Here we demonstrate the concept of an aqueous lithium-iodine (Li-I) solar flow battery (SFB) by incorporation of a built-in dye-sensitized TiO2 photoelectrode in a Li-I redox flow battery via linkage of an I3(-)/I(-) based catholyte, for the simultaneous conversion and storage of solar energy. During the photoassisted charging process, I(-) ions are photoelectrochemically oxidized to I3(-), harvesting solar energy and storing it as chemical energy. The Li-I SFB can be charged at a voltage of 2.90 V under 1 sun AM 1.5 illumination, which is lower than its discharging voltage of 3.30 V. The charging voltage reduction translates to energy savings of close to 20% compared to conventional Li-I batteries. This concept also serves as a guiding design that can be extended to other metal-redox flow battery systems.

  7. The Application of Graphene and Its Derivatives to Energy Conversion, Storage, and Environmental and Biosensing Devices.

    Science.gov (United States)

    Ali Tahir, Asif; Ullah, Habib; Sudhagar, Pitchaimuthu; Asri Mat Teridi, Mohd; Devadoss, Anitha; Sundaram, Senthilarasu

    2016-06-01

    Graphene (GR) and its derivatives are promising materials on the horizon of nanotechnology and material science and have attracted a tremendous amount of research interest in recent years. The unique atom-thick 2D structure with sp(2) hybridization and large specific surface area, high thermal conductivity, superior electron mobility, and chemical stability have made GR and its derivatives extremely attractive components for composite materials for solar energy conversion, energy storage, environmental purification, and biosensor applications. This review gives a brief introduction of GR's unique structure, band structure engineering, physical and chemical properties, and recent energy-related progress of GR-based materials in the fields of energy conversion (e.g., photocatalysis, photoelectrochemical water splitting, CO2 reduction, dye-sensitized and organic solar cells, and photosensitizers in photovoltaic devices) and energy storage (batteries, fuel cells, and supercapacitors). The vast coverage of advancements in environmental applications of GR-based materials for photocatalytic degradation of organic pollutants, gas sensing, and removal of heavy-metal ions is presented. Additionally, the use of graphene composites in the biosensing field is discussed. We conclude the review with remarks on the challenges, prospects, and further development of GR-based materials in the exciting fields of energy, environment, and bioscience. PMID:27230414

  8. The Application of Graphene and Its Derivatives to Energy Conversion, Storage, and Environmental and Biosensing Devices.

    Science.gov (United States)

    Ali Tahir, Asif; Ullah, Habib; Sudhagar, Pitchaimuthu; Asri Mat Teridi, Mohd; Devadoss, Anitha; Sundaram, Senthilarasu

    2016-06-01

    Graphene (GR) and its derivatives are promising materials on the horizon of nanotechnology and material science and have attracted a tremendous amount of research interest in recent years. The unique atom-thick 2D structure with sp(2) hybridization and large specific surface area, high thermal conductivity, superior electron mobility, and chemical stability have made GR and its derivatives extremely attractive components for composite materials for solar energy conversion, energy storage, environmental purification, and biosensor applications. This review gives a brief introduction of GR's unique structure, band structure engineering, physical and chemical properties, and recent energy-related progress of GR-based materials in the fields of energy conversion (e.g., photocatalysis, photoelectrochemical water splitting, CO2 reduction, dye-sensitized and organic solar cells, and photosensitizers in photovoltaic devices) and energy storage (batteries, fuel cells, and supercapacitors). The vast coverage of advancements in environmental applications of GR-based materials for photocatalytic degradation of organic pollutants, gas sensing, and removal of heavy-metal ions is presented. Additionally, the use of graphene composites in the biosensing field is discussed. We conclude the review with remarks on the challenges, prospects, and further development of GR-based materials in the exciting fields of energy, environment, and bioscience.

  9. Potential Impacts of Hydrokinetic and Wave Energy Conversion Technologies on Aquatic Environments

    Energy Technology Data Exchange (ETDEWEB)

    Čada, Glenn F.

    2007-04-01

    A new generation of hydropower technologies, the kinetic hydro and wave energy conversion devices, offers the possibility of generating electricity from the movements of water, without the need for dams and diversions. The Energy Policy Act of 2005 encouraged the development of these sources of renewable energy in the United States, and there is growing interest in deploying them globally. The technologies that would extract electricity from free-flowing streams, estuaries, and oceans have not been widely tested. Consequently, the U.S. Department of Energy convened a workshop to (1) identify the varieties of hydrokinetic energy and wave energy conversion devices and their stages of development, (2) identify where these technologies can best operate, (3) identify the potential environmental issues associated with these technologies and possible mitigation measures, and (4) develop a list of research needs and/or practical solutions to address unresolved environmental issues. The article reviews the results of that workshop, focusing on potential effects on freshwater, estuarine, and marine ecosystems, and we describe recent national and international developments.

  10. Study on the Feasibility of Direct Fusion Energy Conversion for Deep-Space Propulsion

    Science.gov (United States)

    Tarditi, Alfonso G.; Miley, George H.; Scott, John H.

    2012-10-01

    A significant change in the current space mission capabilities can be achieved with a highly efficient integration of a fusion energy source with an advanced space propulsion thruster, both with low specific mass. With aneutronic nuclear fusion as the high-density primary energy source, this study considers first electric energy extraction from the fusion reaction products via direct energy conversion to recirculate power as required for the operation of the fusion core. Then the beam of remaining reaction products is conditioned to achieve the optimal thrust and specific impulse for the mission. The research is specifically focused on two key issues: (i) Efficiency improvement of a Traveling Wave Direct Energy Converter (TWDEC, [1]) by achieving a higher ion beam density and optimization of the electrode coupling and of the neutralizing electron flow. (ii) A fast-particle kinetic energy-to-thrust conversion process based on collective interaction between ion bunches well separated in space [2]. Computer simulation results and a design for a basic physics experiment currently under development are reported. [4pt] [1] H. Momota et al., Fus. Tech., 35, 60(1999)[0pt] [2] A. G. Tarditi et al. Proc. NETS 2012 Conf., Woodlands, TX (2012)

  11. 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.

  12. An efficient biomimetic coating methodology for a prosthetic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Adawy, Alaa, E-mail: a.adawy@science.ru.nl [Physics Department, Faculty of Science, Ain Shams University, Abbassia, Cairo (Egypt); Abdel-Fattah, Wafa I. [Biomaterials Department, National Research Centre, Giza (Egypt)

    2013-04-01

    The combination of the load-bearing metallic implants with the bioactive materials in the design of synthetic implants is an important aspect in the biomaterials research. Biomimetic coating of bioinert alloys with calcium phosphate phases provides a good alternative to the prerequisite for the continual replacement of implants because of the failure of bone-implant integration. We attempted to accelerate the biomimetic coating process of stainless steel alloy (316L) with biomimetic apatite. In addition, we investigated the incorporation of functioning minerals such as strontianite and smithsonite into the deposited layer. In order to develop a highly mature apatite coating, our method requires soaking of the pre-treated alloy in highly concentrated synthetic body fluid for only few hours. Surface characterizations were performed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). Also, the deposited apatitic layers were analysed by powder diffraction X-ray analysis (XRD). 316L surface showed the growth of highly crystalline, low carbonated hydroxyapatite, after only 6 h of the whole soaking process. Highlights: ► The manuscript describes a fast and efficient biomimetic coating methodology. ► This methodology can be used for metallic implants. ► 316L was coated with crystalline hydroxyapatite. ► Addition of strontium and zinc lead to the deposition of brushite. ► Coating of all synthetic solutions is highly crystalline.

  13. A General Mathematical Framework for Calculating Systems-Scale Efficiency of Energy Extraction and Conversion: Energy Return on Investment (EROI and Other Energy Return Ratios

    Directory of Open Access Journals (Sweden)

    Adam R. Brandt

    2011-08-01

    Full Text Available The efficiencies of energy extraction and conversion systems are typically expressed using energy return ratios (ERRs such as the net energy ratio (NER or energy return on investment (EROI. A lack of a general mathematical framework prevents inter-comparison of NER/EROI estimates between authors: methods used are not standardized, nor is there a framework for succinctly reporting results in a consistent fashion. In this paper we derive normalized mathematical forms of four ERRs for energy extraction and conversion pathways. A bottom-up (process model formulation is developed for an n-stage energy harvesting and conversion pathway with various system boundaries. Formations with the broadest system boundaries use insights from life cycle analysis to suggest a hybrid process model/economic input output based framework. These models include indirect energy consumption due to external energy inputs and embodied energy in materials. Illustrative example results are given for simple energy extraction and conversion pathways. Lastly, we discuss the limitations of this approach and the intersection of this methodology with “top-down” economic approaches.

  14. Low Power Thermodynamic Solar Energy Conversion: Coupling of a Parabolic Trough Concentrator and an Ericsson Engine

    Directory of Open Access Journals (Sweden)

    Pascal Stouffs

    2007-03-01

    Full Text Available This paper considers thermodynamic conversion of solar energy into electric energy (up to maximum 50 kWe, presenting a very brief review of the possible systems: the ‘Dish/Stirling’ technology, which relies on high temperature Stirling engines and requires high solar energy; low temperature differential thermal engine using direct solar energy without any concentration but with very low power per unit volume or unit mass of the system; and the intermediate solar energy concentration ratio.A theoretical investigation on the coupling of a two-stage parabolic trough concentrator with a reciprocating Joule cycle air engine (i.e. an Ericsson hot air engine in open cycle is presented. It is shown that there is an optimal operating point that maximises the mechanical power produced by the thermal engine. The interest of coupling a simple, low cost parabolic trough and a simple, low technology, mid-DT Ericsson engine is confirmed.

  15. Bio-mimetic Flow Control

    Science.gov (United States)

    Choi, Haecheon

    2009-11-01

    Bio-mimetic engineering or bio-mimetics is the application of biological methods and systems found in nature to the study and design of engineering systems and modern technology (from Wikipedia). The concept itself is old, but successful developments have been made recently, especially in the research field of flow control. The objective of flow control based on the bio-mimetic approach is to develop novel concepts for reducing drag, increasing lift and enhancing aerodynamic performance. For skin friction reduction, a few ideas have been suggested such as the riblet from shark, compliant surface from dolphin, microbubble injection and multiple front-body curvature from penguin, and V-shaped protrusion from sailfish. For form drag reduction, several new attempts have been also made recently. Examples include the V-shaped spanwise grooves from saguaro cactus, overall shape of box fish, longitudinal grooves on scallop shell, bill of swordfish, hooked comb on owl wing, trailing-edge protrusion on dragonfly wing, and fillet. For the enhancement of aerodynamic performance, focuses have been made on the birds, fish and insects: e.g., double layered feather of landing bird, leading-edge serration of humpback-whale flipper, pectoral fin of flying fish, long tail on swallowtail-butterfly wing, wing flapping motion of dragonfly, and alula in birds. Living animals adapt their bodies to better performance in multi purposes, but engineering requires single purpose in most cases. Therefore, bio-mimetic approaches often produce excellent results more than expected. However, they are sometimes based on people's wrong understanding of nature and produce unwanted results. Successes and failures from bio-mimetic approaches in flow control will be discussed in the presentation.

  16. Biotechnological energy conversion in Germany. State of the art, context, perspectives; Biotechnologische Energieumwandlung in Deutschland. Stand, Kontext, Perspektiven

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Germany will phase out from nuclear power up to 2022, and the energy system is transposed in part to renewable energies. In addition to solar energy and wind power biomass will occupy a central place: More than two-thirds of the today provided renewable energy result from biomass. In the regenerative heat and biomass fuel supply biomass is the main energy source. The biotechnological energy conversion is one method to extract storable energy from biomass. The position paper under consideration reports on the importance of the biotechnological energy conversion under application technical and procedural standpoint. It shows how the biotechnological energy conversion particular can contribute outstandingly to the security of supply in Germany and to the reduction of greenhouse gas emissions, if sustainability criteria are applied. In this field, especially for Germany significant value creation opportunities can be created.

  17. Thermoelectric Oxide Modules (TOMs for the Direct Conversion of Simulated Solar Radiation into Electrical Energy

    Directory of Open Access Journals (Sweden)

    Petr Tomeš

    2010-04-01

    Full Text Available The direct conversion of concentrated high temperature solar heat into electrical energy was demonstrated with a series of four–leg thermoelectric oxide modules (TOM. These temperature stable modules were not yet optimized for high efficiency conversion, but served as proof-of-principle for high temperature conversion. They were constructed by connecting two p- (La1.98Sr0.02CuO4 and two n-type (CaMn0.98Nb0.02O3 thermoelements electrically in series and thermally in parallel. The temperature gradient ΔT was applied by a High–Flux Solar Simulator source (HFSS which generates a spectrum similar to solar radiation. The influence of the graphite layer coated on the hot side of the Al2O3 substrate compared to the uncoated surface on ΔT, Pmax and η was studied in detail. The measurements show an almost linear temperature profile along the thermoelectric legs. The maximum output power of 88.8 mW was reached for a TOM with leg length of 5 mm at ΔT = 622 K. The highest conversion efficiency η was found for a heat flux of 4–8 W cm-2 and the dependence of η on the leg length was investigated.

  18. N-Losses and Energy Use in a Scenario for Conversion to Organic Farming

    Directory of Open Access Journals (Sweden)

    Tommy Dalgaard

    2001-01-01

    Full Text Available The aims of organic farming include the recycling of nutrients and organic matter and the minimisa-tion of the environmental impact of agriculture. Reduced nitrogen (N-losses and energy (E-use are therefore fundamental objectives of conversion to organic farming. However, the case is not straightforward, and different scenarios for conversion to organic farming might lead to reduced or increased N-losses and E-use. This paper presents a scenario tool that uses a Geographical Information System in association with models for crop rotations, fertilisation practices, N-losses, and E-uses. The scenario tool has been developed within the multidisciplinary research project Land Use and Landscape Development Illustrated with Scenarios (ARLAS. A pilot scenario was carried out, where predicted changes in N-losses and E-uses following conversion to organic farming in areas with special interests in clean groundwater were compared. The N-surplus and E-use were on average reduced by 10 and 54%, respectively. However, these reductions following the predicted changes in crop rotations, livestock densities, and fertilisation practices were not large enough to ensure a statistically significant reduction at the 95% level. We therefore recommend further research in how conversion to organic farming or other changes in the agricultural practice might help to reduce N-surpluses and E-uses. In that context, the presented scenario tool would be useful.

  19. Novel Control for Voltage Boosted Matrix Converter based Wind Energy Conversion System with Practicality

    Science.gov (United States)

    Kumar, Vinod; Joshi, Raghuveer Raj; Yadav, Dinesh Kumar; Garg, Rahul Kumar

    2016-06-01

    This paper presents the implementation and investigation of novel voltage boosted matrix converter (MC) based permanent magnet wind energy conversion system (WECS). In this paper, on-line tuned adaptive fuzzy control algorithm cooperated with reversed MC is proposed to yield maximum energy. The control system is implemented on a dSPACE DS1104 real time board. Feasibility of the proposed system has been experimentally verified using a laboratory 1.2 kW prototype of WECS under steady-state and dynamic conditions.

  20. A comparative study between three sensorless control strategies for PMSG in wind energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Brahmi, Jemaa; Krichen, Lotfi; Ouali, Abderrazak [Advanced Control and Energy Management Research Unit ENIS, Department of Electrical Engineering, University of Sfax, 3038 Sfax (Tunisia)

    2009-09-15

    This paper presents a comparative study of sliding mode, artificial neural network and model reference adaptive speed observers for a speed sensorless permanent magnet synchronous generator (PMSG) in wind energy conversion system (WECS). Wind velocity and position sensorless operating methods for wind generation system using observer are proposed only by measuring phase voltages and currents. Maximum wind energy extraction is achieved by running the wind turbine generator in variable-speed mode. In addition the three speed observers are compared to verify the robustness against parameter variations. (author)

  1. Environmental Monitoring Techniques and Equipment related to the installation and operation of Marine Energy Conversion Systems

    International Nuclear Information System (INIS)

    Results of activities under project Marine Renewables Infrastructure Network for Emerging Energy Technologies (MaRINET) are reported, which led to DEMTE, a database, created on the basis of standardized monitoring of the marine environment during installation, operation and decommissioning of Marine Energy Conversion Systems. Obtained with the consortium partners’ available techniques and equipment, the database shows that such instruments cover all identified marine environmental compartments, despite the lack of underwater vehicles and the reduced skills in using satellite technologies. These weaknesses could be overcome by an accurate planning of equipment, techniques and knowledge sharing. The approach here presented also leads to an effective analysis even in non-marine contexts

  2. 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.

  3. 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. PMID:21799983

  4. Generators for Wind Energy Conversion Systems: State of the Art and Coming Attractions

    Directory of Open Access Journals (Sweden)

    Y. Amirat*

    2007-03-01

    Full Text Available Wind Energy Conversion Systems (WECS have become a focal point in the research of renewable energy sources. This paper provides then a comparative study of past and present generator technologies used in WECS. This study is based on an exhaustive review of the state of the art and on an effective comparison of the performances of the four main topologies that are permanent magnet generators, synchronous generators, induction generators and doubly-fed induction generators. The different generator-WECS schemes are compared on the basis of topology, cost, efficiency, power consumption and control complexity. Moreover, attempts are made to highlight future issues so as to index some emerging solutions.

  5. Hot-electron-based solar energy conversion with metal-semiconductor nanodiodes.

    Science.gov (United States)

    Lee, Young Keun; Lee, Hyosun; Lee, Changhwan; Hwang, Euyheon; Park, Jeong Young

    2016-06-29

    Energy dissipation at metal surfaces or interfaces between a metal and a dielectric generally results from elementary excitations, including phonons and electronic excitation, once external energy is deposited to the surface/interface during exothermic chemical processes or an electromagnetic wave incident. In this paper, we outline recent research activities to develop energy conversion devices based on hot electrons. We found that photon energy can be directly converted to hot electrons and that hot electrons flow through the interface of metal-semiconductor nanodiodes where a Schottky barrier is formed and the energy barrier is much lower than the work function of the metal. The detection of hot electron flow can be successfully measured using the photocurrent; we measured the photoyield of photoemission with incident photons-to-current conversion efficiency (IPCE). We also show that surface plasmons (i.e. the collective oscillation of conduction band electrons induced by interaction with an electromagnetic field) are excited on a rough metal surface and subsequently decay into secondary electrons, which gives rise to enhancement of the IPCE. Furthermore, the unique optical behavior of surface plasmons can be coupled with dye molecules, suggesting the possibility for producing additional channels for hot electron generation. PMID:27168177

  6. Hot-electron-based solar energy conversion with metal–semiconductor nanodiodes

    Science.gov (United States)

    Lee, Young Keun; Lee, Hyosun; Lee, Changhwan; Hwang, Euyheon; Park, Jeong Young

    2016-06-01

    Energy dissipation at metal surfaces or interfaces between a metal and a dielectric generally results from elementary excitations, including phonons and electronic excitation, once external energy is deposited to the surface/interface during exothermic chemical processes or an electromagnetic wave incident. In this paper, we outline recent research activities to develop energy conversion devices based on hot electrons. We found that photon energy can be directly converted to hot electrons and that hot electrons flow through the interface of metal–semiconductor nanodiodes where a Schottky barrier is formed and the energy barrier is much lower than the work function of the metal. The detection of hot electron flow can be successfully measured using the photocurrent; we measured the photoyield of photoemission with incident photons-to-current conversion efficiency (IPCE). We also show that surface plasmons (i.e. the collective oscillation of conduction band electrons induced by interaction with an electromagnetic field) are excited on a rough metal surface and subsequently decay into secondary electrons, which gives rise to enhancement of the IPCE. Furthermore, the unique optical behavior of surface plasmons can be coupled with dye molecules, suggesting the possibility for producing additional channels for hot electron generation.

  7. Hot-electron-based solar energy conversion with metal-semiconductor nanodiodes.

    Science.gov (United States)

    Lee, Young Keun; Lee, Hyosun; Lee, Changhwan; Hwang, Euyheon; Park, Jeong Young

    2016-06-29

    Energy dissipation at metal surfaces or interfaces between a metal and a dielectric generally results from elementary excitations, including phonons and electronic excitation, once external energy is deposited to the surface/interface during exothermic chemical processes or an electromagnetic wave incident. In this paper, we outline recent research activities to develop energy conversion devices based on hot electrons. We found that photon energy can be directly converted to hot electrons and that hot electrons flow through the interface of metal-semiconductor nanodiodes where a Schottky barrier is formed and the energy barrier is much lower than the work function of the metal. The detection of hot electron flow can be successfully measured using the photocurrent; we measured the photoyield of photoemission with incident photons-to-current conversion efficiency (IPCE). We also show that surface plasmons (i.e. the collective oscillation of conduction band electrons induced by interaction with an electromagnetic field) are excited on a rough metal surface and subsequently decay into secondary electrons, which gives rise to enhancement of the IPCE. Furthermore, the unique optical behavior of surface plasmons can be coupled with dye molecules, suggesting the possibility for producing additional channels for hot electron generation.

  8. 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.

  9. Graphene and graphene-like layered transition metal dichalcogenides in energy conversion and storage.

    Science.gov (United States)

    Wang, Hua; Feng, Hongbin; Li, Jinghong

    2014-06-12

    Being confronted with the energy crisis and environmental problems, the exploration of clean and renewable energy materials as well as their devices are urgently demanded. Two-dimensional (2D) atomically-thick materials, graphene and grpahene-like layered transition metal dichalcogenides (TMDs), have showed vast potential as novel energy materials due to their unique physicochemical properties. In this Review, we outline the typical application of graphene and grpahene-like TMDs in energy conversion and storage fields, and hope to promote the development of 2D TMDs in this field through the analysis and comparisons with the relatively natural graphene. First, a brief introduction of electronic structures and basic properties of graphene and TMDs are presented. Then, we summarize the exciting progress of these materials made in both energy conversion and storage field including solar cells, electrocatalysis, supercapacitors and lithium ions batteries. Finally, the prospects and further developments in these exciting fields of graphene and graphene-like TMDs materials are also suggested.

  10. Computational analysis of gas-solid interactions in materials for energy storage and conversion

    DEFF Research Database (Denmark)

    Lysgaard, Steen

    . The focus is specifically on the investigation of catalytic materials for electrochemical CO2 fixation into fuels as well as ammonia storage materials, using computational methods relying on density functional theory (DFT) and effective medium theory (EMT) calculations as well as a genetic algorithm....... Nanoparticles of binary alloys have previously been shown to be catalytically active for electrochemical CO2 fixation. The stability of the nanoparticles is critical for a catalytic system. We have developed a method to determine the structure and composition of nanoparticles under reactive conditions...... by a renewable energy production. Sustainable energy sources such as solar or wind power are not constant and efficient methods firstly to convert electricity into chemical energy and secondly to store the high energy materials are needed. In this thesis both issues of conversion and storage are treated...

  11. Feasibility of Traveling Wave Direct Energy Conversion of Fission Reaction Fragments

    Science.gov (United States)

    Tarditi, A. G.; George, J. A.; Miley, G. H.; Scott, J. H.

    2013-01-01

    Fission fragment direct energy conversion has been considered in the past for the purpose of increasing nuclear power plant efficiency and for advanced space propulsion. Since the fragments carry electric charge (typically in the order of 20 e) and have 100 MeV-range kinetic energy, techniques utilizing very high-voltage DC electrodes have been considered. This study is focused on a different approach: the kinetic energy of the charged fission fragments is converted into alternating current by means of a traveling wave coupling scheme (Traveling Wave Direct Energy Converter, TWDEC), thereby not requiring the utilization of high voltage technology. A preliminary feasibility analysis of the concept is introduced based on a conceptual level study and on a particle simulation model of the beam dynamics.

  12. Piezoelectric coupling in energy-harvesting fluttering flexible plates : linear stability analysis and conversion efficiency

    CERN Document Server

    Doare, Olivier

    2011-01-01

    This paper investigates the energy harvested from the flutter of a plate in an axial flow by making use of piezoelectric materials. The equations for fully-coupled linear dynamics of the fluid-solid and electrical systems are derived. The continuous limit is then considered, when the characteristic length of the plate's deformations is large compared to the piezoelectric patches' length. The linear stability analysis of the coupled system is addressed from both a local and global point of view. Piezoelectric energy harvesting adds rigidity and damping on the motion of the flexible plate, and destabilization by dissipation is observed for negative energy waves propagating in the medium. This result is confirmed in the global analysis of fluttering modes of a finite-length plate. It is finally observed that waves or modes destabilized by piezoelectric coupling maximize the energy conversion efficiency.

  13. Facile construction of multicompartment multienzyme system through layer-by-layer self-assembly and biomimetic mineralization.

    Science.gov (United States)

    Shi, Jiafu; Zhang, Lei; Jiang, Zhongyi

    2011-03-01

    In nature, some organelles such as mitochondria and chloroplasts possess multicompartment structure, which render powerful and versatile performance in cascade conversion, selective separation, and energy transfer. In this study, mitochondria-inspired hybrid double membrane microcapsules (HDMMCs) were prepared through synergy between biomimetic mineralization and layer-by-layer (LbL) self-assembly using double templating strategy. The organic inner membrane was acquired via LbL self-assembly of oxidized alginate (o-alginate) and protamine on the CaCO(3) template, the silica template layer was then formed onto the inner membrane through biomimetic silicification using protamine as inducer and silicate as precursor, the organic-inorganic hybrid outer membrane was acquired via biomimetic mineralization of titanium precursor. After the CaCO(3) template and the silica template are removed subsequently, multicompartment microcapsules with microscale lumen and nanoscale intermembrane space were obtained. The double membrane structure of the HDMMCs was verified by high resolution scanning electron microscopy (HRSEM), and the superior mechanical stability of HDMMCs was demonstrated by osmotic pressure experiment and fluorescence microscopy. A multienzyme system was constructed by following this protocol: the first enzyme was encapsulated in the lumen of the HDMMCs, whereas the second enzyme was encapsulated in the intermembrane space. Compared to encapsulated multienzyme in single-compartment microcapsules (SCMCs) or in free form in aqueous solution, enzymatic activity, selectivity, and recycling stability of HDMMCs-enabled multienzyme system were significantly improved. Because of the inherent gentle and generic feature, the present study can be utilized to create a variety of compartment structures for the potential applications in chemical/biological catalysis and separation, drug/gene delivery systems, and biosensors. PMID:21348442

  14. Multi-functional energy conversion and storage electrodes using flower-like Zinc oxide nanostructures

    International Nuclear Information System (INIS)

    In the present paper we demonstrate the efficient use of shape controlled flower-like ZnO (Zinc oxide) nanostructured particles as multifunctional electrode for both energy conversion and storage applications, i.e. Dye-sensitized Solar Cells (DSCs) and lithium-ion batteries. As regards DSC (Dye-sensitized Solar Cell) device, ZnO flower-like particles, prepared by a simple, low-cost and reliable hydrothermal method under mild reaction temperature, are efficiently used as photoanode in a microfluidic architectured cell in combination with NMBI (N-methylbenzimidazole), employed as additive of the electrolytic solution for the first time in a ZnO-based DSC. We obtain a remarkable sunlight conversion efficiency of 3.6%. As regards storage applications, a stable long-term ambient temperature cycling behavior in lithium cell is demonstrated, even at increasingly higher currents. Remarkable charge-discharge efficiency and specific capacity are obtained up to 200 cycles, which is the highest number of cycles reported so far for similar systems. Noteworthy, such results are achieved without the addition of foreign additives, nor during the synthesis process neither during the electrode preparation, and also no carbon coating on ZnO surface is used. The originality of the present paper consists not only in showing for the first time the efficient operation of such ZnO particles as anode in Li-ion batteries for prolonged cycling, but also in demonstrating the versatile and multifunctional use of the same material for two different energy related applications. The reported results enlighten indeed the promising prospects of the flower-like ZnO nanostructured material for the successful implementation as stable and long-term performing anodic material in the next generation of both energy conversion and storage devices. - Highlights: • Flower-like ZnO (Zinc oxide) nanostructured particles are easily obtained by hydrothermal method. • Low temperature, low cost, scalable and

  15. Combination of carbon nitride and carbon nanotubes: synergistic catalysts for energy conversion.

    Science.gov (United States)

    Gong, Yutong; Wang, Jing; Wei, Zhongzhe; Zhang, Pengfei; Li, Haoran; Wang, Yong

    2014-08-01

    Due to their versatile features and environmental friendliness, functionalized carbon materials show great potential in practical applications, especially in energy conversion. Developing carbon composites with properties that can be modulated by simply changing the ratio of the original materials is an intriguing synthetic strategy. Here, we took cyanamide and multiwalled carbon nanotubes as precursors and introduced a facile method to fabricate a series of graphitic carbon nitride/carbon nanotubes (g-C3 N4 /CNTs) composites. These composites demonstrated different practical applications with different weight ratios of the components, that is, they showed synergistic effects in optoelectronic conversion when g-C3 N4 was the main ingredient and in oxygen reduction reaction (ORR) when CNTs dominated the composites. Our experiments indicated that the high electrical conductivity of carbon nanotubes promoted the transmission of the charges in both cases.

  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. 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.

  18. A space-based combined thermophotovoltaic electric generator and gas laser solar energy conversion system

    Science.gov (United States)

    Yesil, Oktay

    1989-01-01

    This paper describes a spaceborne energy conversion system consisting of a thermophotovoltaic electric generator and a gas laser. As a power source for the converson, the system utilizes an intermediate blackbody cavity heated to a temperature of 2000-2400 K by concentrated solar radiation. A double-layer solar cell of GaAs and Si forms a cylindrical surface concentric to this blackbody cavity, receiving the blackbody radiation and converting it into electricity with cell conversion efficiency of 50 percent or more. If the blackbody cavity encloses a laser medium, the blackbody radiation can also be used to simultaneously pump a lasing gas. The feasibility of blackbody optical pumping at 4.3 microns in a CO2-He gas mixture was experimentally demonstrated.

  19. A solar simulator-pumped gas laser for the direct conversion of solar energy

    Science.gov (United States)

    Weaver, W. R.; Lee, J. H.

    1981-01-01

    Most proposed space power systems are comprised of three general stages, including the collection of the solar radiation, the conversion to a useful form, and the transmission to a receiver. The solar-pumped laser, however, effectively eliminates the middle stage and offers direct photon-to-photon conversion. The laser is especially suited for space-to-space power transmission and communication because of minimal beam spread, low power loss over large distances, and extreme energy densities. A description is presented of the first gas laser pumped by a solar simulator that is scalable to high power levels. The lasant is an iodide C3F7I that as a laser-fusion driver has produced terawatt peak power levels.

  20. Fundamental study of novel mid- and low-temperature solar thermochemical energy conversion

    Institute of Scientific and Technical Information of China (English)

    JIN HongGuang; HONG Hui; SUI Jun; LIU QiBin

    2009-01-01

    A new approach to application of mid- and low-temperature solar thermochemical technology was in-troduced and investigated. Concentrated solar thermal energy in the range of 150--300℃ can be effi-ciently converted into high-grade solar fuel by integrating this technique with the endothermic reaction of hydrocarbons. The conversion mechanism of upgrading the low-grade solar thermal energy to high-grade chemical energy was examined based on the energy level. The new mechanism was used to integrate two novel solar thermal power systems: A solar/methanol fuel hybrid thermal power plant and a solar-hybrid combined cycle with inherent CO2 separation using chemical-looping combustion, for developing highly efficient solar energy use to generate electricity. An innovative prototype of a 5-kW solar receiver/reactor, as the key process for realizing the proposed system, was designed and manu-factured. Furthermore, experimental validation of energy conversion of the mid- and low-temperature solar thermochemical processes were conducted. In addition, a second practical and viable approach to the production of hydrogen, in combination with the novel mid- and low-temperature solar thermo-chemical process, was proposed and demonstrated experimentally in the manufactured solar re-ceiver/reactor prototype through methanol steam reforming. The results obtained here indicate that the development of mid- and low-temperature solar thermochemical technology may provide a promising and new direction to efficient utilization of low-grade solar thermal energy, and may enable step-wise approaches to cost-effective, globally scalable solar energy systems.