WorldWideScience

Sample records for based energy storage

  1. Advanced fibre based energy storage.

    OpenAIRE

    Reid, Daniel

    2017-01-01

    New energy storage devices are required to enable future technologies. With the rise of wearable consumer and medical devices, a suitable flexible and wearable means of storing electrical energy is required. Fibre-based devices present a possible method of achieving this aim. Fibres are inherently more flexible than their bulk counterparts, and as such can be employed to form the electrodes of flexible batteries and capacitors. They also present a facile possibility for incorporation into man...

  2. Advanced Fibre Based Energy Storage

    Science.gov (United States)

    Reid, Daniel Oliver

    New energy storage devices are required to enable future technologies. With the rise of wearable consumer and medical devices, a suitable flexible and wearable means of storing electrical energy is required. Fibre-based devices present a possible method of achieving this aim. Fibres are inherently more flexible than their bulk counterparts, and as such can be employed to form the electrodes of flexible batteries and capacitors. They also present a facile possibility for incorporation into many fabrics and clothes, further boosting their potential for use in wearable devices. Electrically conducting fibres were produced from a dispersion of carbon nanomaterials in a room temperature ionic liquid. Coagulation of this dispersion was achieved through manual injection into aqueous solutions of xanthan gum. The limitations of this method are highlighted by very low ultimate tensile strengths of these fibres, in the order of 3 MPa, with high variation within all of the fibres. Fibres were also produced via scrolling of bi-component films containing poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and poly(vinyl alcohol) (PVA). Chemical treatments were employed to impart water compatibility to these fibres, and their electrochemical, physical and electrical properties were analysed. Fibres were wet spun from two PEDOT:PSS sources, in several fibre diameters. The effect of chemical treatments on the fibres were investigated and compared. Short 5 min treatment times with dimethyl sulfoxide (DMSO) on 20 mum fibres produced from Clevios PH1000 were found to produce the best overall treatment. Up to a six-fold increase in electrical conductivity resulted, reaching 800 S cm-1, with up to 40 % increase in specific capacitance and no loss of mechanical strength (55 F g-1 and 150 MPa recorded). A wet spinning system to produce PEDOT:PSS fibres containing functionalised graphenes and carbon nanotubes, as well as birnessite nanotubes was subsequently developed

  3. Graphene-Based Systems for Energy Storage

    Science.gov (United States)

    Calle, Carlos I.; Mackey, Paul J.; Johansen, Michael R.; Phillips, James, III; Hogue, Michael; Kaner, Richard B.; El-Kady, Maher

    2016-01-01

    Development of graphene-based energy storage devices based on the Laser Scribe system developed by the University of California Los Angeles. These devices These graphene-based devices store charge on graphene sheets and take advantage of the large accessible surface area of graphene (2,600 m2g) to increase the electrical energy that can be stored. The proposed devices should have the electrical storage capacity of thin-film-ion batteries but with much shorter charge discharge cycle times as well as longer lives The proposed devices will be carbon-based and so will not have the same issues with flammability or toxicity as the standard lithium-based storage cells.

  4. Energy storage

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role that energy storage may have on the energy future of the US. The topics discussed in the chapter include historical aspects of energy storage, thermal energy storage including sensible heat storage, latent heat storage, thermochemical heat storage, and seasonal heat storage, electricity storage including batteries, pumped hydroelectric storage, compressed air energy storage, and superconducting magnetic energy storage, and production and combustion of hydrogen as an energy storage option

  5. Hydrogen based energy storage for solar energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Vanhanen, J.P.; Hagstroem, M.T.; Lund, P.H. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Engineering Physics and Mathematics; Leppaenen, J.R.; Nieminen, J.P. [Neste Oy (Finland)

    1998-12-31

    Hydrogen based energy storage options for solar energy systems was studied in order to improve their overall performance. A 1 kW photovoltaic hydrogen (PV-H2) pilot-plant and commercial prototype were constructed and a numerical simulation program H2PHOTO for system design and optimisation was developed. Furthermore, a comprehensive understanding of conversion (electrolysers and fuel cells) and storage (metal hydrides) technologies was acquired by the project partners. The PV-H{sub 2} power system provides a self-sufficient solution for applications in remote locations far from electric grids and maintenance services. (orig.)

  6. Hydrogen-based electrochemical energy storage

    Science.gov (United States)

    Simpson, Lin Jay

    2013-08-06

    An energy storage device (100) providing high storage densities via hydrogen storage. The device (100) includes a counter electrode (110), a storage electrode (130), and an ion conducting membrane (120) positioned between the counter electrode (110) and the storage electrode (130). The counter electrode (110) is formed of one or more materials with an affinity for hydrogen and includes an exchange matrix for elements/materials selected from the non-noble materials that have an affinity for hydrogen. The storage electrode (130) is loaded with hydrogen such as atomic or mono-hydrogen that is adsorbed by a hydrogen storage material such that the hydrogen (132, 134) may be stored with low chemical bonding. The hydrogen storage material is typically formed of a lightweight material such as carbon or boron with a network of passage-ways or intercalants for storing and conducting mono-hydrogen, protons, or the like. The hydrogen storage material may store at least ten percent by weight hydrogen (132, 134) at ambient temperature and pressure.

  7. Energy Storage.

    Science.gov (United States)

    Eaton, William W.

    Described are technological considerations affecting storage of energy, particularly electrical energy. The background and present status of energy storage by batteries, water storage, compressed air storage, flywheels, magnetic storage, hydrogen storage, and thermal storage are discussed followed by a review of development trends. Included are…

  8. Research on Battery Energy Storage System Based on User Side

    Science.gov (United States)

    Wang, Qian; Zhang, Yichi; Yun, Zejian; Wang, Xuguang; Zhang, Dong; Bian, Di

    2018-01-01

    This paper introduces the effect of user side energy storage on the user side and the network side, a battery energy storage system for the user side is designed. The main circuit topology of the battery energy storage system based on the user side is given, the structure is mainly composed of two parts: DC-DC two-way half bridge converter and DC-AC two-way converter, a control strategy combining battery charging and discharging characteristics is proposed to decouple the grid side and the energy storage side, and the block diagram of the charging and discharging control of the energy storage system is given. The simulation results show that the battery energy storage system of the user side can not only realize reactive power compensation of low-voltage distribution network, but also improve the power quality of the users.

  9. Energy storage

    International Nuclear Information System (INIS)

    2012-01-01

    After having outlined the importance of energy storage in the present context, this document outlines that it is an answer to economic, environmental and technological issues. It proposes a brief overview of the various techniques of energy storage: under the form of chemical energy (hydrocarbons, biomass, hydrogen production), thermal energy (sensitive or latent heat storage), mechanical energy (potential energy by hydraulic or compressed air storage, kinetic energy with flywheels), electrochemical energy (in batteries), electric energy (super-capacitors, superconductor magnetic energy storage). Perspectives are briefly evoked

  10. Hydrogen based energy storage for solar energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Vanhanen, J.; Hagstroem, M.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Advanced Energy Systems

    1998-10-01

    The main technical constraint in solar energy systems which operate around the year is the lack of suitable long-term energy storage. Conventional solutions to overcome the problem of seasonal storage in PV power systems are to use oversized batteries as a seasonal energy storage, or to use a diesel back-up generator. However, affordable lead-acid batteries are not very suitable for seasonal energy storage because of a high self-discharge rate and enhanced deterioration and divergence of the single cells during prolonged periods of low state of charge in times of low irradiation. These disadvantages can be avoided by a back-up system, e.g. a diesel generator, which car supply energy to the loads and charge the battery to the full state of charge to avoid the above mentioned disadvantages. Unfortunately, diesel generators have several disadvantages, e.g. poor starting reliability, frequent need for maintenance and noise

  11. Energy storage

    Science.gov (United States)

    Kaier, U.

    1981-04-01

    Developments in the area of energy storage are characterized, with respect to theory and laboratory, by an emergence of novel concepts and technologies for storing electric energy and heat. However, there are no new commercial devices on the market. New storage batteries as basis for a wider introduction of electric cars, and latent heat storage devices, as an aid for solar technology applications, with satisfactory performance standards are not yet commercially available. Devices for the intermediate storage of electric energy for solar electric-energy systems, and for satisfying peak-load current demands in the case of public utility companies are considered. In spite of many promising novel developments, there is yet no practical alternative to the lead-acid storage battery. Attention is given to central heat storage for systems transporting heat energy, small-scale heat storage installations, and large-scale technical energy-storage systems.

  12. Thermal energy storage based on cementitious materials: A review

    Directory of Open Access Journals (Sweden)

    Khadim Ndiaye

    2018-01-01

    Full Text Available Renewable energy storage is now essential to enhance the energy performance of buildings and to reduce their environmental impact. Many heat storage materials can be used in the building sector in order to avoid the phase shift between solar radiation and thermal energy demand. However, the use of storage material in the building sector is hampered by problems of investment cost, space requirements, mechanical performance, material stability, and high storage temperature. Cementitious material is increasingly being used as a heat storage material thanks to its low price, mechanical performance and low storage temperature (generally lower than 100 °C. In addition, cementitious materials for heat storage have the prominent advantage of being easy to incorporate into the building landscape as self-supporting structures or even supporting structures (walls, floor, etc.. Concrete solutions for thermal energy storage are usually based on sensible heat transfer and thermal inertia. Phase Change Materials (PCM incorporated in concrete wall have been widely investigated in the aim of improving building energy performance. Cementitious material with high ettringite content stores heat by a combination of physical (adsorption and chemical (chemical reaction processes usable in both the short (daily, weekly and long (seasonal term. Ettringite materials have the advantage of high energy storage density at low temperature (around 60 °C. The encouraging experimental results in the literature on heat storage using cementitious materials suggest that they could be attractive in a number of applications. This paper summarizes the investigation and analysis of the available thermal energy storage systems using cementitious materials for use in various applications.

  13. Energy storage

    CERN Document Server

    Brunet, Yves

    2013-01-01

    Energy storage examines different applications such as electric power generation, transmission and distribution systems, pulsed systems, transportation, buildings and mobile applications. For each of these applications, proper energy storage technologies are foreseen, with their advantages, disadvantages and limits. As electricity cannot be stored cheaply in large quantities, energy has to be stored in another form (chemical, thermal, electromagnetic, mechanical) and then converted back into electric power and/or energy using conversion systems. Most of the storage technologies are examined: b

  14. Energy Storage

    CSIR Research Space (South Africa)

    Bladergroen, B

    2015-10-01

    Full Text Available will be an important tool in the toolbox of system designers – together with primary energy providers solar PV, wind, biogas and potentially backup through diesel-based generators. Outside the electricity sector, eMobility will largely drive the demand for battery...-to-Fuel is, together with eMobility, the connector between the historically separated electricity and transport sector. Challenge Questions  What will drive the future battery market?  Is energy storage a necessary condition for a large uptake...

  15. Graphene-Based Carbon Materials for Electrochemical Energy Storage

    Directory of Open Access Journals (Sweden)

    Fei Liu

    2013-01-01

    Full Text Available Because of their unique 2D structure and numerous fascinating properties, graphene-based materials have attracted particular attention for their potential applications in energy storage devices. In this review paper, we focus on the latest work regarding the development of electrode materials for batteries and supercapacitors from graphene and graphene-based carbon materials. To begin, the advantages of graphene as an electrode material and the existing problems facing its use in this application will be discussed. The next several sections deal with three different methods for improving the energy storage performance of graphene: the restacking of the nanosheets, the doping of graphene with other elements, and the creation of defects on graphene planes. State-of-the-art work is reviewed. Finally, the prospects and further developments in the field of graphene-based materials for electrochemical energy storage are discussed.

  16. Nanostructured Mo-based electrode materials for electrochemical energy storage.

    Science.gov (United States)

    Hu, Xianluo; Zhang, Wei; Liu, Xiaoxiao; Mei, Yueni; Huang, Yunhui

    2015-04-21

    The development of advanced energy storage devices is at the forefront of research geared towards a sustainable future. Nanostructured materials are advantageous in offering huge surface to volume ratios, favorable transport features, and attractive physicochemical properties. They have been extensively explored in various fields of energy storage and conversion. This review is focused largely on the recent progress in nanostructured Mo-based electrode materials including molybdenum oxides (MoO(x), 2 ≤ x ≤ 3), dichalconides (MoX2, X = S, Se), and oxysalts for rechargeable lithium/sodium-ion batteries, Mg batteries, and supercapacitors. Mo-based compounds including MoO2, MoO3, MoO(3-y) (0 nanostructured Mo-based compounds, as well as their energy storage applications in lithium/sodium-ion batteries, Mg batteries, and pseudocapacitors. The relationship between nanoarchitectures and electrochemical performances as well as the related charge-storage mechanism is discussed. Moreover, remarks on the challenges and perspectives of Mo-containing compounds for further development in electrochemical energy storage applications are proposed. This review sheds light on the sustainable development of advanced rechargeable batteries and supercapacitors with nanostructured Mo-based electrode materials.

  17. Metal hydride-based thermal energy storage systems

    Science.gov (United States)

    Vajo, John J.; Fang, Zhigang

    2017-10-03

    The invention provides a thermal energy storage system comprising a metal-containing first material with a thermal energy storage density of about 1300 kJ/kg to about 2200 kJ/kg based on hydrogenation; a metal-containing second material with a thermal energy storage density of about 200 kJ/kg to about 1000 kJ/kg based on hydrogenation; and a hydrogen conduit for reversibly transporting hydrogen between the first material and the second material. At a temperature of 20.degree. C. and in 1 hour, at least 90% of the metal is converted to the hydride. At a temperature of 0.degree. C. and in 1 hour, at least 90% of the metal hydride is converted to the metal and hydrogen. The disclosed metal hydride materials have a combination of thermodynamic energy storage densities and kinetic power capabilities that previously have not been demonstrated. This performance enables practical use of thermal energy storage systems for electric vehicle heating and cooling.

  18. Polyaniline (PANi based electrode materials for energy storage and conversion

    Directory of Open Access Journals (Sweden)

    Huanhuan Wang

    2016-09-01

    Full Text Available Polyaniline (PANi as one kind of conducting polymers has been playing a great role in the energy storage and conversion devices besides carbonaceous materials and metallic compounds. Due to high specific capacitance, high flexibility and low cost, PANi has shown great potential in supercapacitor. It alone can be used in fabricating an electrode. However, the inferior stability of PANi limits its application. The combination of PANi and other active materials (carbon materials, metal compounds or other polymers can surpass these intrinsic disadvantages of PANi. This review summarizes the recent progress in PANi based composites for energy storage/conversion, like application in supercapacitors, rechargeable batteries, fuel cells and water hydrolysis. Besides, PANi derived nitrogen-doped carbon materials, which have been widely employed as carbon based electrodes/catalysts, are also involved in this review. PANi as a promising material for energy storage/conversion is deserved for intensive study and further development.

  19. Energy storage

    International Nuclear Information System (INIS)

    Hermans, J.H.W.E.

    1998-01-01

    A brief overview is given of the research activities of the Dutch association for energy distribution companies EnergieNed in the field of energy storage techniques, carried out within the framework of the long-range programme Study and Research (MSO, abbreviated in Dutch)

  20. Geothermally Coupled Well-Based Compressed Air Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, Casie L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horner, Jacob A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cabe, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Appriou, Delphine [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGrail, B. Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-12-20

    . This project assessed the technical and economic feasibility of implementing geothermally coupled well-based CAES for grid-scale energy storage. Based on an evaluation of design specifications for a range of casing grades common in U.S. oil and gas fields, a 5-MW CAES project could be supported by twenty to twenty-five 5,000-foot, 7-inch wells using lower-grade casing, and as few as eight such wells for higher-end casing grades. Using this information, along with data on geothermal resources, well density, and potential future markets for energy storage systems, The Geysers geothermal field was selected to parameterize a case study to evaluate the potential match between the proven geothermal resource present at The Geysers and the field’s existing well infrastructure. Based on calculated wellbore compressed air mass, the study shows that a single average geothermal production well could provide enough geothermal energy to support a 15.4-MW (gross) power generation facility using 34 to 35 geothermal wells repurposed for compressed air storage, resulting in a simplified levelized cost of electricity (sLCOE) estimated at 11.2 ¢/kWh (Table S.1). Accounting for the power loss to the geothermal power project associated with diverting geothermal resources for air heating results in a net 2-MW decrease in generation capacity, increasing the CAES project’s sLCOE by 1.8 ¢/kWh.

  1. Geothermally Coupled Well-Based Compressed Air Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, C L [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horner, Jacob A [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Appriou, Delphine [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGrail, B Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-12-01

    . This project assessed the technical and economic feasibility of implementing geothermally coupled well-based CAES for grid-scale energy storage. Based on an evaluation of design specifications for a range of casing grades common in U.S. oil and gas fields, a 5-MW CAES project could be supported by twenty to twenty-five 5,000-foot, 7-inch wells using lower-grade casing, and as few as eight such wells for higher-end casing grades. Using this information, along with data on geothermal resources, well density, and potential future markets for energy storage systems, The Geysers geothermal field was selected to parameterize a case study to evaluate the potential match between the proven geothermal resource present at The Geysers and the field’s existing well infrastructure. Based on calculated wellbore compressed air mass, the study shows that a single average geothermal production well could provide enough geothermal energy to support a 15.4-MW (gross) power generation facility using 34 to 35 geothermal wells repurposed for compressed air storage, resulting in a simplified levelized cost of electricity (sLCOE) estimated at 11.2 ¢/kWh (Table S.1). Accounting for the power loss to the geothermal power project associated with diverting geothermal resources for air heating results in a net 2-MW decrease in generation capacity, increasing the CAES project’s sLCOE by 1.8 ¢/kWh.

  2. Graphene-Based Integrated Photovoltaic Energy Harvesting/Storage Device.

    Science.gov (United States)

    Chien, Chih-Tao; Hiralal, Pritesh; Wang, Di-Yan; Huang, I-Sheng; Chen, Chia-Chun; Chen, Chun-Wei; Amaratunga, Gehan A J

    2015-06-24

    Energy scavenging has become a fundamental part of ubiquitous sensor networks. Of all the scavenging technologies, solar has the highest power density available. However, the energy source is erratic. Integrating energy conversion and storage devices is a viable route to obtain self-powered electronic systems which have long-term maintenance-free operation. In this work, we demonstrate an integrated-power-sheet, consisting of a string of series connected organic photovoltaic cells (OPCs) and graphene supercapacitors on a single substrate, using graphene as a common platform. This results in lighter and more flexible power packs. Graphene is used in different forms and qualities for different functions. Chemical vapor deposition grown high quality graphene is used as a transparent conductor, while solution exfoliated graphene pastes are used as supercapacitor electrodes. Solution-based coating techniques are used to deposit the separate components onto a single substrate, making the process compatible with roll-to-roll manufacture. Eight series connected OPCs based on poly(3-hexylthiophene)(P3HT):phenyl-C61-butyric acid methyl ester (PC60 BM) bulk-heterojunction cells with aluminum electrodes, resulting in a ≈5 V open-circuit voltage, provide the energy harvesting capability. Supercapacitors based on graphene ink with ≈2.5 mF cm(-2) capacitance provide the energy storage capability. The integrated-power-sheet with photovoltaic (PV) energy harvesting and storage functions had a mass of 0.35 g plus the substrate. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Scenario simulation based assessment of subsurface energy storage

    Science.gov (United States)

    Beyer, C.; Bauer, S.; Dahmke, A.

    2014-12-01

    Energy production from renewable sources such as solar or wind power is characterized by temporally varying power supply. The politically intended transition towards renewable energies in Germany („Energiewende") hence requires the installation of energy storage technologies to compensate for the fluctuating production. In this context, subsurface energy storage represents a viable option due to large potential storage capacities and the wide prevalence of suited geological formations. Technologies for subsurface energy storage comprise cavern or deep porous media storage of synthetic hydrogen or methane from electrolysis and methanization, or compressed air, as well as heat storage in shallow or moderately deep porous formations. Pressure build-up, fluid displacement or temperature changes induced by such operations may affect local and regional groundwater flow, geomechanical behavior, groundwater geochemistry and microbiology. Moreover, subsurface energy storage may interact and possibly be in conflict with other "uses" like drinking water abstraction or ecological goods and functions. An utilization of the subsurface for energy storage therefore requires an adequate system and process understanding for the evaluation and assessment of possible impacts of specific storage operations on other types of subsurface use, the affected environment and protected entities. This contribution presents the framework of the ANGUS+ project, in which tools and methods are developed for these types of assessments. Synthetic but still realistic scenarios of geological energy storage are derived and parameterized for representative North German storage sites by data acquisition and evaluation, and experimental work. Coupled numerical hydraulic, thermal, mechanical and reactive transport (THMC) simulation tools are developed and applied to simulate the energy storage and subsurface usage scenarios, which are analyzed for an assessment and generalization of the imposed THMC

  4. Estimation of Supercapacitor Energy Storage Based on Fractional Differential Equations

    Science.gov (United States)

    Kopka, Ryszard

    2017-12-01

    In this paper, new results on using only voltage measurements on supercapacitor terminals for estimation of accumulated energy are presented. For this purpose, a study based on application of fractional-order models of supercapacitor charging/discharging circuits is undertaken. Parameter estimates of the models are then used to assess the amount of the energy accumulated in supercapacitor. The obtained results are compared with energy determined experimentally by measuring voltage and current on supercapacitor terminals. All the tests are repeated for various input signal shapes and parameters. Very high consistency between estimated and experimental results fully confirm suitability of the proposed approach and thus applicability of the fractional calculus to modelling of supercapacitor energy storage.

  5. Estimation of Supercapacitor Energy Storage Based on Fractional Differential Equations.

    Science.gov (United States)

    Kopka, Ryszard

    2017-12-22

    In this paper, new results on using only voltage measurements on supercapacitor terminals for estimation of accumulated energy are presented. For this purpose, a study based on application of fractional-order models of supercapacitor charging/discharging circuits is undertaken. Parameter estimates of the models are then used to assess the amount of the energy accumulated in supercapacitor. The obtained results are compared with energy determined experimentally by measuring voltage and current on supercapacitor terminals. All the tests are repeated for various input signal shapes and parameters. Very high consistency between estimated and experimental results fully confirm suitability of the proposed approach and thus applicability of the fractional calculus to modelling of supercapacitor energy storage.

  6. Hybrid Carbon-Based Clathrates for Energy Storage

    Directory of Open Access Journals (Sweden)

    Kwai S. Chan

    2018-01-01

    Full Text Available Hybrid carbon–silicon, carbon–nitrogen, and carbon–boron clathrates are new classes of Type I carbon-based clathrates that have been identified by first-principles computational methods by substituting atoms on the carbon clathrate framework with Si, N, and/or B atoms. The hybrid framework is further stabilized by embedding appropriate guest atoms within the cavities of the cage structure. Series of hybrid carbon–silicon, carbon–boron, carbon–nitrogen, and carbon-silicon-nitrogen clathrates have been shown to exhibit small positive values for the energy of formation, indicating that they may be metastable compounds and amenable to fabrication. In this overview article, the energy of formation, elastic properties, and electronic properties of selected hybrid carbon-based clathrates are summarized. Theoretical calculations that explore the potential applications of hybrid carbon-based clathrates as energy storage materials, electronic materials, or hard materials are presented. The computational results identify compositions of hybrid carbon–silicon and carbon–nitrogen clathrates that may be considered as candidate materials for use as either electrode materials for Li-ion batteries or as hydrogen storage materials. Prior processing routes for fabricating selected hybrid carbon-based clathrates are highlighted and the difficulties encountered are discussed.

  7. Energy storage cells

    Energy Technology Data Exchange (ETDEWEB)

    Gulia, N.V.

    1980-01-01

    The book deals with the characteristics and potentialities of energy storage cells of various types. Attention is given to electrical energy storage cells (electrochemical, electrostatic, and electrodynamic cells), mechanical energy storage cells (mechanical flywheel storage cells), and hybrid storage systems.

  8. Energy storage

    International Nuclear Information System (INIS)

    Odru, P.

    2010-01-01

    This book proposes a broad overview of the technologies developed in the domains of on-board electricity storage (batteries, super-capacitors, flywheels), stationary storage (hydraulic dams, compressed air, batteries and hydrogen), and heat storage (sensible, latent and sorption) together with their relative efficiency, their expected developments and what advantages they can offer. Eminent specialists of this domain have participated to the redaction of this book, all being members of the Tuck's Foundation 'IDees' think tank. (J.S.)

  9. Seasonal thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

    1984-05-01

    This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

  10. Performance Study of Salt Cavern Air Storage Based Non-Supplementary Fired Compressed Air Energy Storage System

    Science.gov (United States)

    Chen, Xiaotao; Song, Jie; Liang, Lixiao; Si, Yang; Wang, Le; Xue, Xiaodai

    2017-10-01

    Large-scale energy storage system (ESS) plays an important role in the planning and operation of smart grid and energy internet. Compressed air energy storage (CAES) is one of promising large-scale energy storage techniques. However, the high cost of the storage of compressed air and the low capacity remain to be solved. This paper proposes a novel non-supplementary fired compressed air energy storage system (NSF-CAES) based on salt cavern air storage to address the issues of air storage and the efficiency of CAES. Operating mechanisms of the proposed NSF-CAES are analysed based on thermodynamics principle. Key factors which has impact on the system storage efficiency are thoroughly explored. The energy storage efficiency of the proposed NSF-CAES system can be improved by reducing the maximum working pressure of the salt cavern and improving inlet air pressure of the turbine. Simulation results show that the electric-to-electric conversion efficiency of the proposed NSF-CAES can reach 63.29% with a maximum salt cavern working pressure of 9.5 MPa and 9 MPa inlet air pressure of the turbine, which is higher than the current commercial CAES plants.

  11. Flexible energy storage devices based on nanocomposite paper.

    Science.gov (United States)

    Pushparaj, Victor L; Shaijumon, Manikoth M; Kumar, Ashavani; Murugesan, Saravanababu; Ci, Lijie; Vajtai, Robert; Linhardt, Robert J; Nalamasu, Omkaram; Ajayan, Pulickel M

    2007-08-21

    There is strong recent interest in ultrathin, flexible, safe energy storage devices to meet the various design and power needs of modern gadgets. To build such fully flexible and robust electrochemical devices, multiple components with specific electrochemical and interfacial properties need to be integrated into single units. Here we show that these basic components, the electrode, separator, and electrolyte, can all be integrated into single contiguous nanocomposite units that can serve as building blocks for a variety of thin mechanically flexible energy storage devices. Nanoporous cellulose paper embedded with aligned carbon nanotube electrode and electrolyte constitutes the basic unit. The units are used to build various flexible supercapacitor, battery, hybrid, and dual-storage battery-in-supercapacitor devices. The thin freestanding nanocomposite paper devices offer complete mechanical flexibility during operation. The supercapacitors operate with electrolytes including aqueous solvents, room temperature ionic liquids, and bioelectrolytes and over record temperature ranges. These easy-to-assemble integrated nanocomposite energy-storage systems could provide unprecedented design ingenuity for a variety of devices operating over a wide range of temperature and environmental conditions.

  12. Design and Simulation of Dual Inverter Based Energy Storage Systems for Wind Energy Systems Using MATLAB/SIMULINK

    OpenAIRE

    Harika G,; Jayakumar N

    2014-01-01

    This paper proposes the design and simulation of dual inverter based Energy Storage Systems(ESS) for wind energy systems. A dual inverter consists of MAIN inverter which is connected to grid side and an auxiliary inverter for which an energy storage system is interfaced. Typical grid connected wind energy systems includes wind turbine, PMSG, DC-DC converters, three phase dual inverter ,energy storage system and related power electronic devices. The detailed model of design and...

  13. Superconducting magnetic energy storage

    International Nuclear Information System (INIS)

    Rogers, J.D.; Boenig, H.J.

    1978-01-01

    Superconducting inductors provide a compact and efficient means of storing electrical energy without an intermediate conversion process. Energy storage inductors are under development for diurnal load leveling and transmission line stabilization in electric utility systems and for driving magnetic confinement and plasma heating coils in fusion energy systems. Fluctuating electric power demands force the electric utility industry to have more installed generating capacity than the average load requires. Energy storage can increase the utilization of base-load fossil and nuclear power plants for electric utilities. Superconducting magnetic energy storage (SMES) systems, which will store and deliver electrical energy for load leveling, peak shaving, and the stabilization of electric utility networks are being developed. In the fusion area, inductive energy transfer and storage is also being developed by LASL. Both 1-ms fast-discharge theta-pinch and 1-to-2-s slow tokamak energy transfer systems have been demonstrated. The major components and the method of operation of an SMES unit are described, and potential applications of different size SMES systems in electric power grids are presented. Results are given for a 1-GWh reference design load-leveling unit, for a 30-MJ coil proposed stabilization unit, and for tests with a small-scale, 100-kJ magnetic energy storage system. The results of the fusion energy storage and transfer tests are also presented. The common technology base for the systems is discussed

  14. Flexible energy storage devices based on nanocomposite paper

    OpenAIRE

    Pushparaj, Victor L.; Shaijumon, Manikoth M.; Kumar, Ashavani; Murugesan, Saravanababu; Ci, Lijie; Vajtai, Robert; Linhardt, Robert J.; Nalamasu, Omkaram; Ajayan, Pulickel M.

    2007-01-01

    There is strong recent interest in ultrathin, flexible, safe energy storage devices to meet the various design and power needs of modern gadgets. To build such fully flexible and robust electrochemical devices, multiple components with specific electrochemical and interfacial properties need to be integrated into single units. Here we show that these basic components, the electrode, separator, and electrolyte, can all be integrated into single contiguous nanocomposite units that can serve as ...

  15. Energy Storage

    CSIR Research Space (South Africa)

    Bladergroen, B

    2015-10-01

    Full Text Available With the emergence of variable renewable energy (VRE) sources, such as solar photovoltaics (PV) and wind power, flexibility requirements in the power system are generally increasing. However, what is not so clear yet is what “increasing flexibility...

  16. Sorption and thermal characterization of composite materials based on chlorides for thermal energy storage

    OpenAIRE

    Korhammer, Kathrin; Druske, Mona-Maria; Fopah-Lele, Armand; Rammelberg, Holger Urs; Wegscheider, Nina; Opel, Oliver; Osterland, Thomas; Ruck, Wolfgang

    2016-01-01

    International audience; Thermochemical heat storage is a promising technology towards efficient use of renewable energy resources. Materials based on salts and their hydrates have a high potential for a good energy storage density and the benefit of long-term storage ability. However, the process has not yet been successfully implemented due to limitations in mass and heat transfer. This paper investigates how to improve the less desirable properties of CaCl2 and its hydrates such as low melt...

  17. Ammonia Based Solar Thermochemical Energy Storage System for Direct Production of High Temperature Supercritical Steam

    OpenAIRE

    CHEN, CHEN

    2017-01-01

    In the field of solar thermochemical energy storage, ammonia synthesis/dissociation is feasible for practical use in the concentrating solar power industry. In ammonia-based solar thermochemical energy storage systems, the stored energy is released when the hydrogen (H2) and nitrogen (N2) react exothermically to synthesize ammonia (NH3), providing thermal energy to a power block for electricity generation. But ammonia synthesis has not yet been shown to reach temperatures consistent with the ...

  18. RSPF-based Prognosis Framework for Estimation of Remaining Useful Life in Energy Storage Devices

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper presents a case study where a RSPF-based prognosis framework is applied to estimate the remaining useful life of an energy storage device (Li-Ion...

  19. Flexible Graphene-based Energy Storage Devices for Space Application Project

    Science.gov (United States)

    Calle, Carlos I.

    2014-01-01

    Develop prototype graphene-based reversible energy storage devices that are flexible, thin, lightweight, durable, and that can be easily attached to spacesuits, rovers, landers, and equipment used in space.

  20. Super Capacitor Energy Storage Based MMC for Energy Harvesting in Mine Hoist Application

    Directory of Open Access Journals (Sweden)

    Xiaofeng Yang

    2017-09-01

    Full Text Available This paper proposes a super capacitor energy storage-based modular multilevel converter (SCES-MMC for mine hoist application. Different from the conventional MMCs, the sub-modules employ distributed super capacitor banks, which are designed to absorb the regenerative energy of mine hoist and released in the traction condition, so as to improve energy utilization efficiency. The key control technologies are introduced in detail, followed by analysis of the configuration and operation principles. The feasibility of the proposed SCES-MMC topology and the control theory are also verified. Simulation results show that SCES-MMC can adapt to the variable frequency speed regulation of the motor drive, which shows good application prospects in the future for medium- and high-voltage mine hoist systems.

  1. Energy storage device based on flywheel, power converters and Simulink real-time

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Kedra, Bartosz; Malkowski, Robert

    2017-01-01

    This electronic document is a 'live' template and already defines the components of your paper [title, text, heads, etc.] in its style sheet. Paper presents information on Energy Storage Device based on Flywheel and bi-directional IGBT Power Converters - designed for LINTE∧2 laboratory owned...... are presented. List and description of all measurements is provided. In the last section of the paper results of experiments using Energy Storage Device based on Flywheel and Power Converters performed in laboratory are presented....

  2. Phenothiazine based polymers for energy and data storage application

    Energy Technology Data Exchange (ETDEWEB)

    Golriz, Seyed Ahmad Ali

    2013-03-15

    charge and discharge cycles. In addition to applications in batteries the bistability of phenothiazine polymers for high density data storage purposes was studied. Using the conductive mode of scanning force microscopy (SFM), nano-scaled patterning of spin-coated polymer films induced by electrochemical oxidation was successfully demonstrated. The scanning probe experiments revealed differences in the conductive states of written patterns before and after oxidation with no significant change in topography. Remarkably, the patterns were stable with respect to the storage time as well as mechanical wear. Finally, new synthetic approaches towards mechanically nanowear stable and redox active surfaces were established. Via grafting from methods based on Atom Transfer Radical Polymerization (ATRP), redox active polymer brushes with phenothiazine moieties were prepared and characterized by SFM and X-ray techniques. In particular, a synthetic route based on polymer brush structures with activated ester functionality appeared as a very promising and versatile fabrication method. The activated ester brushes were used for attachment of phenothiazine moieties in a successive step. By using crosslinkable diamine moieties, polymer brushes with redox functionalities and with increased surface wear resistance were successfully synthesized. In summary, this work offers deep insights into the electronic properties of polymers with phenothiazine redox active moieties. Furthermore, the applicability of phenothiazine polymers for electronic devices was explored and improved from synthetic polymer chemistry point of view.

  3. Graphene Based Ultra-Capacitors for Safer, More Efficient Energy Storage

    Science.gov (United States)

    Roberson, Luke B.; Mackey, Paul J.; Zide, Carson J.

    2016-01-01

    Current power storage methods must be continuously improved in order to keep up with the increasingly competitive electronics industry. This technological advancement is also essential for the continuation of deep space exploration. Today's energy storage industry relies heavily on the use of dangerous and corrosive chemicals such as lithium and phosphoric acid. These chemicals can prove hazardous to the user if the device is ruptured. Similarly they can damage the environment if they are disposed of improperly. A safer, more efficient alternative is needed across a wide range of NASA missions. One solution would a solid-state carbon based energy storage device. Carbon is a safer, less environmentally hazardous alternative to current energy storage materials. Using the amorphous carbon nanostructure, graphene, this idea of a safer portable energy is possible. Graphene was electrochemically produced in the lab and several coin cell devices were built this summer to create a working prototype of a solid-state graphene battery.

  4. Performance analysis of a novel energy storage system based on liquid carbon dioxide

    International Nuclear Information System (INIS)

    Wang, Mingkun; Zhao, Pan; Wu, Yi; Dai, Yiping

    2015-01-01

    Due to the intermittence and fluctuation of wind resource, the increasing penetration level of wind power will bring huge challenges to maintain the stability of power system. Integrating compressed air energy storage (CAES) system with wind farms can weaken this negative effect. However CAES system needs large caverns or mines to store compressed air, which is restricted in application. In this paper, a novel energy storage system based on liquid carbon dioxide is presented. The mathematical models of compressed liquid-carbon dioxide energy storage system are developed. The parametric analysis is conducted to examine the effect of some key thermodynamic parameters on the system performance. Compared with AA-CAES, the liquid carbon dioxide energy storage system has advantages such as a high energy density, high EVR. Moreover, the round trip efficiency of this system can reach about 56.64%, which is acceptable in consideration of the storage volume. Therefore, this proposed system has a good potential for storing wind power in large scale and offers an attractive solution to the challenges of the increasing penetration level of wind power. - Highlights: • A novel energy storage system based on liquid carbon dioxide is presented. • The effects of some key parameters on the system performance are studied. • The operation optimization is conducted by genetic algorithm. • Comparative analysis of AA-CAES and liquid carbon dioxide system is studied.

  5. The hybrid energy storages based on batteries and ultracapacitors for contact microwelding

    Directory of Open Access Journals (Sweden)

    Bondarenko Yu. V.

    2014-08-01

    Full Text Available Micro resistance welding is an effective way to reliably join small-scale parts. It is widely used in electronics and instrument-making. The important particularities of micro resistance welding are pulse character of energy consumption, non-linear load and special form of current pulses. So, these particularities of welding process cause negative influence on the mains. One of the known ways to avoid it is to use autonomous power supplies for micro resistance welding machines. The important task for building autonomous power supplies is to choose effective energy storages, which have high capacity and small internal resistance, and which are capable to be charged and deliver energy to load very quickly. The solution of this task is seen in using hybrid energy storages, which include accumulators and ultracapacitors. The accumulators are able to provide high energy capacitance and the ultracapacitors are able to provide fast energy delivery. The possibility of application of hybrid energy storages, based on accumulator batteries and ultracapacitors, in micro resistance welding machines is confirmed with computer simulation. Two variants of hybrid energy storages are proposed. These hybrid energy storages have high power and dynamic characteristics, which are sufficient to generate current pulses for welding according to necessary settings.

  6. Tool for optimal design and operation of hydrogen storage based autonomous energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Oberschachtsiek, B.; Lemken, D. [ZBT - Duisburg (Germany); Stark, M.; Krost, G. [Duisburg-Essen Univ. (Germany)

    2010-07-01

    Decentralized small scale electricity generation based on renewable energy sources usually necessitates decoupling of volatile power generation and consumption by means of energy storage. Hydrogen has proven as an eligible storage medium for mid- and long-term range, which - when indicated - can be reasonably complemented by accumulator short term storage. The selection of appropriate system components - sources, storage devices and the appertaining peripherals - is a demanding task which affords a high degree of freedom but, on the other hand, has to account for various operational dependencies and restrictions of system components, as well as for conduct of load and generation. An innovative tool facilitates the configuration and dimensioning of renewable energy based power supply systems with hydrogen storage paths, and allows for applying appropriate operation strategies. This tool accounts for the characteristics and performances of relevant power sources, loads, and types of energy storage, and also regards safety rules the energy system has to comply with. In particular, the tool is addressing small, detached and autonomous supply systems. (orig.)

  7. Cu-based materials as high-performance electrodes toward electrochemical energy storage

    Science.gov (United States)

    Chen, Kunfeng; Xue, Dongfeng

    2014-02-01

    Cu-based materials, including metal Cu and semiconductors of Cu2O and CuO, are promising and important candidates toward practical electrochemical energy storage devices due to their abundant, low cost, easy synthesis and environmentally friendly merits. This review presents an overview of the applications of Cu-based materials in the state-of-art electrochemical energy storage, including both lithium-ion batteries and supercapacitors. The synthesis chemistry, structures and the corresponding electrochemical performances of these materials are summarized and compared. During chemical synthesis and electroactive performance measurement of Cu-based materials, we found that Cu-Cu2O-CuO sequence governs all related transformations. Novel water-soluble CuCl2 supercapacitors with ultrahigh capacitance were also reviewed which can advance the understanding of intrinsic mechanism of inorganic pseudocapacitors. The major goal of this review is to highlight some recent progresses in using Cu-based materials for electrochemical energy storage.

  8. 78 FR 4143 - Energy Storage Holdings, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2013-01-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Energy Storage Holdings, LLC; Supplemental Notice That Initial Market-Based... above-referenced proceeding, of Energy Storage Holdings, LLC's application for market-based rate...

  9. Energy Storage and Retrieval

    Indian Academy of Sciences (India)

    GENERAL I ARTICLE. Energy Storage and Retrieval. The Secondary Battery Route. A K Shukla and P Vishnu Kamath. Harnessing sunlight for the production of electrical energy is an engrossing prospect. The crucial concept underlying the success of solar power stations is energy storage and its retrieval on demand which ...

  10. Energy storage technologies

    International Nuclear Information System (INIS)

    Brunet, Y.

    2009-01-01

    This book takes stock of the advantages and drawbacks of the different energy storage solutions apart from the classical fossil fuels (oil, uranium, gas), and details the technologies developed for an electric end-use. Storage is one of the most critical point for the development of new energy technologies, in particular those that use the electricity vector all along the energy source chain (generation, production, transport, utilisation). Storage is important not only for individual or independent applications, that use renewable energies or not, often intermittent, but also to secure coupled systems like power transportation and distribution systems. The development and choice of the most relevant technologies is dependent of technical-economical parameters. It can also supply new services, in particular in the framework of new electricity markets. Content: power film-capacitors, magnetic storage, kinetic energy storage, compressed air energy storage (CAES), hydro-pneumatic storage, high-temperature thermal storage of electricity, hydraulic gravity storage, power electronic systems for energy storage. (J.S.)

  11. Geometric Process-Based Maintenance and Optimization Strategy for the Energy Storage Batteries

    Directory of Open Access Journals (Sweden)

    Yan Li

    2016-01-01

    Full Text Available Renewable energy is critical for improving energy structure and reducing environment pollution. But its strong fluctuation and randomness have a serious effect on the stability of the microgrid without the coordination of the energy storage batteries. The main factors that influence the development of the energy storage system are the lack of valid operation and maintenance management as well as the cost control. By analyzing the typical characteristics of the energy storage batteries in their life cycle, the geometric process-based model including the deteriorating system and the improving system is firstly built for describing the operation process, the preventive maintenance process, and the corrective maintenance process. In addition, this paper proposes an optimized management strategy, which aims to minimize the long-run average cost of the energy storage batteries by defining the time interval of the detection and preventive maintenance process as well as the optimal corrective maintenance times, subjected to the state of health and the reliability conditions. The simulation is taken under the built model by applying the proposed energy storage batteries’ optimized management strategy, which verifies the effectiveness and applicability of the management strategy, denoting its obvious practicality on the current application.

  12. Potential Coastal Pumped Hydroelectric Energy Storage Locations Identified using GIS-based Topographic Analysis

    Science.gov (United States)

    Parsons, R.; Barnhart, C. J.; Benson, S. M.

    2013-12-01

    Large-scale electrical energy storage could accommodate variable, weather dependent energy resources such as wind and solar. Pumped hydroelectric energy storage (PHS) and compressed energy storage area (CAES) have life cycle energy and financial costs that are an order of magnitude lower than conventional electrochemical storage technologies. However PHS and CAES storage technologies require specific geologic conditions. Conventional PHS requires an upper and lower reservoir separated by at least 100 m of head, but no more than 10 km in horizontal distance. Conventional PHS also impacts fresh water supplies, riparian ecosystems, and hydrologic environments. A PHS facility that uses the ocean as the lower reservoir benefits from a smaller footprint, minimal freshwater impact, and the potential to be located near off shore wind resources and population centers. Although technologically nascent, today one coastal PHS facility exists. The storage potential for coastal PHS is unknown. Can coastal PHS play a significant role in augmenting future power grids with a high faction of renewable energy supply? In this study we employ GIS-based topographic analysis to quantify the coastal PHS potential of several geographic locations, including California, Chile and Peru. We developed automated techniques that seek local topographic minima in 90 m spatial resolution shuttle radar topography mission (SRTM) digital elevation models (DEM) that satisfy the following criteria conducive to PHS: within 10 km from the sea; minimum elevation 150 m; maximum elevation 1000 m. Preliminary results suggest the global potential for coastal PHS could be very significant. For example, in northern Chile we have identified over 60 locations that satisfy the above criteria. Two of these locations could store over 10 million cubic meters of water or several GWh of energy. We plan to report a global database of candidate coastal PHS locations and to estimate their energy storage capacity.

  13. A Low Energy Consumption Storage Method for Cloud Video Surveillance Data Based on SLA Classification

    OpenAIRE

    Yonghua Xiong; Chengda Lu; Min Wu; Keyuan Jiang; Dianhong Wang

    2016-01-01

    With the continuous expansion of the amount of data with time in mobile video applications such as cloud video surveillance (CVS), the increasing energy consumption in video data centers has drawn widespread attention for the past several years. Addressing the issue of reducing energy consumption, we propose a low energy consumption storage method specially designed for CVS systems based onthe service level agreement (SLA) classification. A novel SLA with an extra parameter of access time per...

  14. Flexible Graphene-Based Energy Storage Devices for Space Application

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to develop a graphene-based battery/ultra-capacitor prototype that is flexible, thin, lightweight, durable, low cost, and safe and...

  15. Lyapunov based control of hybrid energy storage system in electric vehicles

    DEFF Research Database (Denmark)

    El Fadil, H.; Giri, F.; Guerrero, Josep M.

    2012-01-01

    This paper deals with a Lyapunov based control principle in a hybrid energy storage system for electric vehicle. The storage system consists on fuel cell (FC) as a main power source and a supercapacitor (SC) as an auxiliary power source. The power stage of energy conversion consists on a boost...... voltage regulations, ii) perfect tracking of SC current to its reference, and iii) asymptotic stability of the closed loop system. It is clearly shown, using formal analysis and simulations that the designed controller meets all the objectives....

  16. Energy Storage System Sizing Based on a Reliability Assessment of Power Systems Integrated with Wind Power

    Directory of Open Access Journals (Sweden)

    Nian Shi

    2017-03-01

    Full Text Available The available capacity is a major factor that influences the reliability contribution of energy storage in power systems integrated with wind power. This paper presents the capacity value of the energy storage metrics to quantitatively estimate the contribution of energy storage to the generation adequacy. A method in accordance with EFC approach has been introduced to model the capacity value of energy storage. The adequacy-oriented model of the energy storage available capacity is proposed for the energy storage system, regarding the roles of the key parameters for the CVES analysis. The case study results indicate that the capacity value of energy storage quantitatively weigh the contribution of the energy storage to system reliability. The sensitivity analysis of the impact factors for the CVES is conducted.

  17. Solar Energy: Heat Storage.

    Science.gov (United States)

    Knapp, Henry H., III

    This module on heat storage is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies. The module…

  18. Flywheel energy storage; Schwungmassenspeicher

    Energy Technology Data Exchange (ETDEWEB)

    Bornemann, H.J. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany)

    1996-12-31

    Energy storages may be chemical systems such as batteries, thermal systems such as hot-water tanks, electromagnetic systems such as capacitors and coils, or mechanical systems such as pumped storage power systems or flywheel energy storages. In flywheel energy storages the energy is stored in the centrifugal mass in the form of kinetic energy. This energy can be converted to electricity via a motor/generator unit and made available to the consumer. The introduction of magnetic bearings has greatly enhanced the potential of flywheel energy storages. As there is no contact between the moving parts of magnetic bearings, this technology provides a means of circumventing the engineering and operational problems involved in the we of conventional bearings (ball, roller, plain, and gas bearings). The advantages of modern flywheel energy storages over conventional accumulators are an at least thousandfold longer service life, low losses during long-time storage, greater power output in the case of short-time storage, and commendable environmental benignity. (orig./HW) [Deutsch] Als Enegiespeicher kommen chemische Systeme, z.B. Batterien, thermische Systeme, z.B. Warmwassertanks, elektromagnetische Systeme, z.B. Kondensatoren und Spulen, sowie mechanische Systeme, z.B. Pumpspeicherwerke und Schwungmassenspeicher in Frage. In einem Schwungmassenspeicher wird Energie in Form von kinetischer Energie in der Schwungmasse gespeichert. Ueber eine Moter/Generator Einheit wird diese Energie in elektrischen Strom umgewandelt und dem Verbraucher zugefuehrt. Mit der Einfuehrung von magnetischen Lagern konnte die Leistungsfaehigkeit von Schwungmassenspeichern erheblich gesteigert werden. Da in einem Magnetlager keine Beruehrung zwischen sich bewegenden Teilen besteht, wird ein Grossteil der mit dem Einsatz konventioneller Lager (Kugel- und Rollenlager, Gleitlager und Gaslager) verbundenen ingenieurtechnischen und betriebstechnischen Probleme vermieden. Die Vorteile von modernen

  19. Thermal energy storage

    Science.gov (United States)

    Grodzka, P. G.; Picklesimer, E. A.

    1978-01-01

    The general scope of study on thermal energy storage development includes: (1) survey and review possible concepts for storing thermal energy; (2) evaluate the potentials of the surveyed concepts for practical applications in the low and high temperature ranges for thermal control and storage, with particular emphasis on the low temperature range, and designate the most promising concepts; and (3) determine the nature of further studies required to expeditiously convert the most promising concept(s) to practical applications. Cryogenic temperature control by means of energy storage materials was also included.

  20. MnO2 Based Nanostructures for Supercapacitor Energy Storage Applications

    KAUST Repository

    Chen, Wei

    2013-11-01

    Nanostructured materials provide new and exciting approaches to the development of supercapacitor electrodes for high-performance electrochemical energy storage applications. One of the biggest challenges in materials science and engineering, however, is to prepare the nanomaterials with desirable characteristics and to engineer the structures in proper ways. This dissertation presents the successful preparation and application of very promising materials in the area of supercapacitor energy storage, including manganese dioxide and its composites, polyaniline and activated carbons. Attention has been paid to understanding their growth process and performance in supercapacitor devices. The morphological and electrochemical cycling effects, which contribute to the understanding of the energy storage mechanism of MnO2 based supercapacitors is thoroughly investigated. In addition, MnO2 based binary (MnO2-carbon nanocoils, MnO2-graphene) and ternary (MnO2-carbon nanotube-graphene) nanocomposites, as well as two novel electrodes (MnO2-carbon nanotube-textile and MnO2-carbon nanotube-sponge) have been studied as supercapacitor electrode materials, showing much improved electrochemical storage performance with good energy and power densities. Furthermore, a general chemical route was introduced to synthesize different conducting polymers and activated carbons by taking the MnO2 nanostructures as reactive templates. The electrochemical behaviors of the polyaniline and activated nanocarbon supercapacitors demonstrate the morphology-dependent enhancement of capacitance. Excellent energy and power densities were obtained from the template-derived polyaniline and activated carbon based supercapacitors, indicating the success of our proposed chemical route toward the preparation of high performance supercapacitor materials. The work discussed in this dissertation conclusively showed the significance of the preparation of desirable nanomaterials and the design of effective

  1. Energy Storage Economics

    Energy Technology Data Exchange (ETDEWEB)

    Elgqvist, Emma M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-07

    This presentation provides an overview on energy storage economics including recent market trends, battery terminology and concepts, value streams, challenges, and an example of how photovoltaics and storage can be used to lower demand charges. It also provides an overview of the REopt Lite web tool inputs and outputs.

  2. Wind-energy storage

    Science.gov (United States)

    Gordon, L. H.

    1980-01-01

    Program SIMWEST can model wind energy storage system using any combination of five types of storage: pumped hydro, battery, thermal, flywheel, and pneumatic. Program is tool to aid design of optional system for given application with realistic simulation for further evaluation and verification.

  3. Fuzzy Logic based Coordinated Control of Battery Energy Storage System and Dispatchable Distributed Generation for Microgrid

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Wang, Chengshan

    2015-01-01

    Microgrid is an efficient solution to integraterenewable energy sources (RES) into power systems. Inorder to deal with the intermittent characteristics of therenewable energy based distributed generation (DG) units,a fuzzy-logic based coordinated control strategy of thebattery energy storage system...... (BESS) and dispatchableDG units is proposed in this paper for the microgridmanagement system (MMS). In the proposed coordinatedcontrol strategy, the BESS is used to mitigate the activepower exchange at the point of common coupling of themicrogrid for the grid-connected operation, and is used forthe...... frequency control for the island operation. Theeffectiveness of the proposed control strategy was verifiedby case studies using DIgSILENT/PowerFactroy....

  4. Integrating Desalination and Energy Storage using a Saltwater-based Hybrid Sodium-ion Supercapacitor.

    Science.gov (United States)

    Guo, Zhaowei; Ma, Yuanyuan; Dong, Xiaoli; Hou, Mengyan; Wang, Yonggang; Xia, Yongyao

    2018-04-15

    Ever-increasing freshwater scarcity and energy crisis problems require efficient seawater desalination and energy storage technologies; however, each target is generally considered separately. Herein, a hybrid sodium-ion supercapacitor, involving a carbon-coated nano-NaTi 2 (PO 4 ) 3 -based battery anode and an activated-carbon-based capacitive cathode, is developed to combine desalination and energy storage in one device. On charge, the supercapacitor removes salt in a flowing saltwater electrolyte through Cl - electrochemical adsorption at the cathode and Na + intercalation at the anode. Discharge delivers useful electric energy and regenerates the electrodes. This supercapacitor can be used not only for energy storage with promising electrochemical performance (i.e., high power, high efficiency, and long cycle life), but also as a desalination device with desalination capacity of 146.8 mg g -1 , much higher than most reported capacitive and battery desalination devices. Finally, we demonstrate renewables to usable electric energy and desalted water through combining commercial photovoltaics and this hybrid supercapacitor. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Technology Roadmap: Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-03-01

    Energy storage technologies are valuable components in most energy systems and could be an important tool in achieving a low-carbon future. These technologies allow for the decoupling of energy supply and demand, in essence providing a valuable resource to system operators. There are many cases where energy storage deployment is competitive or near-competitive in today's energy system. However, regulatory and market conditions are frequently ill-equipped to compensate storage for the suite of services that it can provide. Furthermore, some technologies are still too expensive relative to other competing technologies (e.g. flexible generation and new transmission lines in electricity systems). One of the key goals of this new roadmap is to understand and communicate the value of energy storage to energy system stakeholders. This will include concepts that address the current status of deployment and predicted evolution in the context of current and future energy system needs by using a ''systems perspective'' rather than looking at storage technologies in isolation.

  6. Thermal energy storage

    Science.gov (United States)

    Tomlinson, J. J.

    1992-03-01

    The Department of Energy (DOE) is supporting development of thermal energy storage (TES) as a means of efficiently coupling energy supplies to variable heating or cooling demands. Uses of TES include electrical demand-side management in buildings and industry, extending the utilization of renewable energy resources such as solar, and recovery of waste heat from periodic industrial processes. Technical progress to develop TES for specific diurnal and industrial applications under Oak Ridge National Laboratory's TES program from April 1990 to March 1992 is reported and covers research in the areas of low temperature sorption, direct contact ice making, latent heat storage plasterboard and latent/sensible heat regenerator technology development.

  7. Evaluation of in-situ thermal energy storage for lunar based solar dynamic systems

    Science.gov (United States)

    Crane, Roger A.

    1991-01-01

    A practical lunar based thermal energy storage system, based on locally available materials, could significantly reduce transportation requirements and associated costs of a continuous, solar derived power system. The concept reported here is based on a unique, in-situ approach to thermal energy storage. The proposed design is examined to assess the problems of start-up and the requirements for attainment of stable operation. The design remains, at this stage, partially conceptional in nature, but certain aspects of the design, bearing directly on feasibility, are examined in some detail. Specifically included is an engineering evaluation of the projected thermal performance of this system. Both steady state and start-up power requirements are evaluated and the associated thermal losses are evaluated as a basis for establishing potential system performance.

  8. One dimensional Si/Sn - based nanowires and nanotubes for lithium-ion energy storage materials

    KAUST Repository

    Choi, Nam-Soon

    2011-01-01

    There has been tremendous interest in using nanomaterials for advanced Li-ion battery electrodes, particularly to increase the energy density by using high specific capacity materials. Recently, it was demonstrated that one dimensional (1D) Si/Sn nanowires (NWs) and nanotubes (NTs) have great potential to achieve high energy density as well as long cycle life for the next generation of advanced energy storage applications. In this feature article, we review recent progress on Si-based NWs and NTs as high capacity anode materials. Fundamental understanding and future challenges on one dimensional nanostructured anode are also discussed. © 2010 The Royal Society of Chemistry.

  9. Advanced Graphene-Based Binder-Free Electrodes for High-Performance Energy Storage.

    Science.gov (United States)

    Ji, Junyi; Li, Yang; Peng, Wenchao; Zhang, Guoliang; Zhang, Fengbao; Fan, Xiaobin

    2015-09-23

    The increasing demand for energy has triggered tremendous research effort for the development of high-performance and durable energy-storage devices. Advanced graphene-based electrodes with high electrical conductivity and ion accessibility can exhibit superior electrochemical performance in energy-storage devices. Among them, binder-free configurations can enhance the electron conductivity of the electrode, which leads to a higher capacity by avoiding the addition of non-conductive and inactive binders. Graphene, a 2D material, can be fabricated into a porous and flexible structure with an interconnected conductive network. Such a conductive structure is favorable for both electron and ion transport to the entire electrode surface. In this review, the main processes used to prepare binder-free graphene-based hybrids with high porosity and well-designed electron conductive networks are summarized. Then, the applications of free-standing binder-free graphene-based electrodes in energy-storage devices are discussed. Future research aspects with regard to overcoming the technological bottlenecks are also proposed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Science.gov (United States)

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

    2016-08-14

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

  11. 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.

  12. Energy storage device with large charge separation

    Energy Technology Data Exchange (ETDEWEB)

    Holme, Timothy P.; Prinz, Friedrich B.; Iancu, Andrei T.

    2018-04-03

    High density energy storage in semiconductor devices is provided. There are two main aspects of the present approach. The first aspect is to provide high density energy storage in semiconductor devices based on formation of a plasma in the semiconductor. The second aspect is to provide high density energy storage based on charge separation in a p-n junction.

  13. Energy storage device with large charge separation

    Science.gov (United States)

    Holme, Timothy P.; Prinz, Friedrich B.; Iancu, Andrei

    2016-04-12

    High density energy storage in semiconductor devices is provided. There are two main aspects of the present approach. The first aspect is to provide high density energy storage in semiconductor devices based on formation of a plasma in the semiconductor. The second aspect is to provide high density energy storage based on charge separation in a p-n junction.

  14. Electrochemical energy storage

    CERN Document Server

    Tarascon, Jean-Marie

    2015-01-01

    The electrochemical storage of energy has become essential in assisting the development of electrical transport and use of renewable energies. French researchers have played a key role in this domain but Asia is currently the market leader. Not wanting to see history repeat itself, France created the research network on electrochemical energy storage (RS2E) in 2011. This book discusses the launch of RS2E, its stakeholders, objectives, and integrated structure that assures a continuum between basic research, technological research and industries. Here, the authors will cover the technological

  15. A Low Energy Consumption Storage Method for Cloud Video Surveillance Data Based on SLA Classification

    Directory of Open Access Journals (Sweden)

    Yonghua Xiong

    2016-01-01

    Full Text Available With the continuous expansion of the amount of data with time in mobile video applications such as cloud video surveillance (CVS, the increasing energy consumption in video data centers has drawn widespread attention for the past several years. Addressing the issue of reducing energy consumption, we propose a low energy consumption storage method specially designed for CVS systems based onthe service level agreement (SLA classification. A novel SLA with an extra parameter of access time period is proposed and then utilized as a criterion for dividing virtual machines (VMs and data storage nodes into different classifications. Tasks can be scheduled in real time for running on the homologous VMs and data storage nodes according to their access time periods. Any nodes whose access time periods do not encompass the current time will be placed into the energy saving state while others are in normal state with the capability of undertaking tasks. As a result, overall electric energy consumption in data centers is reduced while the SLA is fulfilled. To evaluate the performance, we compare the method with two related approaches using the Hadoop Distributed File System (HDFS. The results show the superiority and effectiveness of our method.

  16. Tri-generation based hybrid power plant scheduling for renewable resources rich area with energy storage

    International Nuclear Information System (INIS)

    Pazheri, F.R.

    2015-01-01

    Highlights: • Involves scheduling of the tri-generation based hybrid power plant. • Utilization of renewable energy through energy storage is discussed. • Benefits of the proposed model are illustrated. • Energy efficient and environmental friendly dispatch is analyzed. • Modeled scheduling problem is applicable to any fuel enriched area. - Abstract: Solving power system scheduling is crucial to ensure smooth operations of the electric power industry. Effective utilization of available conventional and renewable energy sources (RES) by tri-generation and with the aid of energy storage facilities (ESF) can ensure clean and energy efficient power generation. Such power generation can play an important role in countries, like Saudi Arabia, where abundant fossil fuels (FF) and renewable energy sources (RES) are available. Hence, effective modeling of such hybrid power systems scheduling is essential in such countries based on the available fuel resources. The intent of this paper is to present a simple model for tri-generation based hybrid power system scheduling for energy resources rich area in presence of ESF, to ensure optimum fuel utilization and minimum pollutant emissions while meeting the power demand. This research points an effective operation strategy which ensure a clean and energy efficient power scheduling by exploiting available energy resources effectively. Hence, it has an important role in current and future power generation. In order to illustrate the benefits of the presented approach a clean and energy efficient hybrid power supply scheme for King Saud University (KSU), Saudi Arabia, is proposed and analyzed here. Results show that the proposed approach is very suitable for KSU since adequate solar power is available during its peak demand periods

  17. Energy storage connection system

    Science.gov (United States)

    Benedict, Eric L.; Borland, Nicholas P.; Dale, Magdelena; Freeman, Belvin; Kite, Kim A.; Petter, Jeffrey K.; Taylor, Brendan F.

    2012-07-03

    A power system for connecting a variable voltage power source, such as a power controller, with a plurality of energy storage devices, at least two of which have a different initial voltage than the output voltage of the variable voltage power source. The power system includes a controller that increases the output voltage of the variable voltage power source. When such output voltage is substantially equal to the initial voltage of a first one of the energy storage devices, the controller sends a signal that causes a switch to connect the variable voltage power source with the first one of the energy storage devices. The controller then causes the output voltage of the variable voltage power source to continue increasing. When the output voltage is substantially equal to the initial voltage of a second one of the energy storage devices, the controller sends a signal that causes a switch to connect the variable voltage power source with the second one of the energy storage devices.

  18. Energy Storage Criteria Handbook.

    Science.gov (United States)

    1982-10-01

    derived from the process of electrolysis in which electri- city is used to break water, H20, into its constituents, H and 0. The hydrogen and oxygen are...cavity because of incipient problems with surface brine . There are some problems with air leakage also. Storage in porous media covers variable pressure...with hydrogen and oxygen is more likely to be useful in an energy storage application. The hydrogen and oxygen can be initially generated by electrolysis

  19. Design of Anti-Windup Compensator for Energy Storage-Based Damping Controller to Enhance Power System Stability

    DEFF Research Database (Denmark)

    Fang, Jiakun; Yao, Wei; Chen, Zhe

    2014-01-01

    The application of energy storage (ES) in power system is limited due to the high cost of the ES device, which exponentially increases with its capacity. This paper is to improve the saturation-dependent stability of the power system equipped with the energy storage based damping controller (ESDC...

  20. Aluminum and silicon based phase change materials for high capacity thermal energy storage

    International Nuclear Information System (INIS)

    Wang, Zhengyun; Wang, Hui; Li, Xiaobo; Wang, Dezhi; Zhang, Qinyong; Chen, Gang; Ren, Zhifeng

    2015-01-01

    Six compositions of aluminum (Al) and silicon (Si) based materials: 87.8Al-12.2Si, 80Al–20Si, 70Al–30Si, 60Al–40Si, 45Al–40Si–15Fe, and 17Al–53Si–30Ni (atomic ratio), were investigated for potentially high thermal energy storage (TES) application from medium to high temperatures (550–1200 °C) through solid–liquid phase change. Thermal properties such as melting point, latent heat, specific heat, thermal diffusivity and thermal conductivity were investigated by differential scanning calorimetry and laser flash apparatus. The results reveal that the thermal storage capacity of the Al–Si materials increases with increasing Si concentration. The melting point and latent heat of 45Al–40Si–15Fe and 17Al–53Si–30Ni are ∼869 °C and ∼562 J g −1 , and ∼1079 °C and ∼960 J g −1 , respectively. The measured thermal conductivity of Al–Si binary materials depend on Si concentration and is higher than 80 W m −1  K −1 from room temperature to 500 °C, which is almost two orders of magnitude higher than those of salts that are commonly used phase change material for thermal energy storage. - Highlights: • Six kinds of materials were investigated for thermal energy storage (550–1200 °C). • Partial melting of Al–Si materials show progressively changing temperatures. • Studied materials can be used in three different working temperature ranges. • Materials are potentially good candidates for thermal energy storage applications.

  1. Electrochemical energy storage in montmorillonite K10 clay based composite as supercapacitor using ionic liquid electrolyte.

    Science.gov (United States)

    Maiti, Sandipan; Pramanik, Atin; Chattopadhyay, Shreyasi; De, Goutam; Mahanty, Sourindra

    2016-02-15

    Exploring new electrode materials is the key to realize high performance energy storage devices for effective utilization of renewable energy. Natural clays with layered structure and high surface area are prospective materials for electrical double layer capacitors (EDLC). In this work, a novel hybrid composite based on acid-leached montmorillonite (K10), multi-walled carbon nanotube (MWCNT) and manganese dioxide (MnO2) was prepared and its electrochemical properties were investigated by fabricating two-electrode asymmetric supercapacitor cells against activated carbon (AC) using 1.0M tetraethylammonium tetrafluroborate (Et4NBF4) in acetonitrile (AN) as electrolyte. The asymmetric supercapacitors, capable of operating in a wide potential window of 0.0-2.7V, showed a high energy density of 171Whkg(-1) at a power density of ∼1.98kWkg(-1). Such high EDLC performance could possibly be linked to the acid-base interaction of K10 through its surface hydroxyl groups with the tetraethylammonium cation [(C2H5)4N(+) or TEA(+)] of the ionic liquid electrolyte. Even at a very high power density of 96.4kWkg(-1), the cells could still deliver an energy density of 91.1Whkg(-1) exhibiting an outstanding rate capability. The present study demonstrates for the first time, the excellent potential of clay-based composites for high power energy storage device applications. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Design of Energy Storage Management System Based on FPGA in Micro-Grid

    Science.gov (United States)

    Liang, Yafeng; Wang, Yanping; Han, Dexiao

    2018-01-01

    Energy storage system is the core to maintain the stable operation of smart micro-grid. Aiming at the existing problems of the energy storage management system in the micro-grid such as Low fault tolerance, easy to cause fluctuations in micro-grid, a new intelligent battery management system based on field programmable gate array is proposed : taking advantage of FPGA to combine the battery management system with the intelligent micro-grid control strategy. Finally, aiming at the problem that during estimation of battery charge State by neural network, initialization of weights and thresholds are not accurate leading to large errors in prediction results, the genetic algorithm is proposed to optimize the neural network method, and the experimental simulation is carried out. The experimental results show that the algorithm has high precision and provides guarantee for the stable operation of micro-grid.

  3. Dealloying of Cu-Based Metallic Glasses in Acidic Solutions: Products and Energy Storage Applications.

    Science.gov (United States)

    Wang, Zhifeng; Liu, Jiangyun; Qin, Chunling; Yu, Hui; Xia, Xingchuan; Wang, Chaoyang; Zhang, Yanshan; Hu, Qingfeng; Zhao, Weimin

    2015-04-29

    Dealloying, a famous ancient etching technique, was used to produce nanoporous metals decades ago. With the development of dealloying techniques and theories, various interesting dealloying products including nanoporous metals/alloys, metal oxides and composites, which exhibit excellent catalytic, optical and sensing performance, have been developed in recent years. As a result, the research on dealloying products is of great importance for developing new materials with superior physical and chemical properties. In this paper, typical dealloying products from Cu-based metallic glasses after dealloying in hydrofluoric acid and hydrochloric acid solutions are summarized. Several potential application fields of these dealloying products are discussed. A promising application of nanoporous Cu (NPC) and NPC-contained composites related to the energy storage field is introduced. It is expected that more promising dealloying products could be developed for practical energy storage applications.

  4. SoC-Based Droop Method for Distributed Energy Storage in DC Microgrid Applications

    DEFF Research Database (Denmark)

    Lu, Xiaonan; Sun, Kai; Guerrero, Josep M.

    2012-01-01

    With the progress of distributed generation nowadays, microgrid is employed to integrate different renewable energy sources into a certain area. For several kinds of renewable sources have DC outputs, DC microgrid has drawn more attention recently. Meanwhile, to deal with the uncertainty...... in the output of microgrid system, distributed energy storage is usually adopted. Considering that the state-of-charge (SoC) of each battery may not be the same, decentralized droop control method based on SoC is shown in this paper to reach proportional load power sharing. With this method, the battery...

  5. Thermal energy storage material

    Science.gov (United States)

    Leifer, Leslie

    1976-01-01

    A thermal energy storage material which is stable at atmospheric temperature and pressure and has a melting point higher than 32.degree.F. is prepared by dissolving a specific class of clathrate forming compounds, such as tetra n-propyl or tetra n-butyl ammonium fluoride, in water to form a substantially solid clathrate. The resultant thermal energy storage material is capable of absorbing heat from or releasing heat to a given region as it transforms between solid and liquid states in response to temperature changes in the region above and below its melting point.

  6. Superconducting magnetic energy storage

    International Nuclear Information System (INIS)

    Rogers, J.D.

    1976-01-01

    Fusion power production requires energy storage and transfer on short time scales to create confining magnetic fields and for heating plasmas. The theta-pinch Scyllac Fusion Test Reactor (SFTR) requires 480 MJ of energy to drive the 5-T compression field with a 0.7-ms rise time. Tokamak Experimental Power Reactors (EPR) require 1 to 2 GJ of energy with a 1 to 2-s rise time for plasma ohmic heating. The design, development, and testing of four 300-kJ energy storage coils to satisfy the SFTR needs are described. Potential rotating machinery and homopolar energy systems for both the Reference Theta-Pinch Reactor (RTPR) and tokamak ohmic-heating are presented

  7. Hydrogen-based energy storage unit for stand alone PV systems

    International Nuclear Information System (INIS)

    Labbe, J.

    2006-12-01

    Stand alone systems supplied only by a photovoltaic generator need an energy storage unit to be fully self sufficient. Lead acid batteries are commonly used to store energy because of their low cost, despite several operational constraints. A hydrogen-based energy storage unit (HESU) could be another candidate, including an electrolyser, a fuel cell and a hydrogen tank. However many efforts still need to be carried out for this technology to reach an industrial stage. In particular, market outlets must be clearly identified. The study of small stationary applications (few kW) is performed by numerical simulations. A simulator is developed in the Matlab/Simulink environment. It is mainly composed of a photovoltaic field and a storage unit (lead acid batteries, HESU, or hybrid storage HESU/batteries). The system component sizing is achieved in order to ensure the complete system autonomy over a whole year of operation. The simulator is tested with 160 load profiles (1 kW as a yearly mean value) and three locations (Algeria, France and Norway). Two coefficients are set in order to quantify the correlation between the power consumption of the end user and the renewable resource availability at both daily and yearly scales. Among the tested cases, a limit value of the yearly correlation coefficient came out, enabling to recommend the use of the most adapted storage to a considered case. There are cases for which using HESU instead of lead acid batteries can increase the system efficiency, decrease the size of the photovoltaic field and improve the exploitation of the renewable resource. In addition, hybridization of HESU with batteries always leads to system enhancements regarding its sizing and performance, with an efficiency increase by 10 to 40 % depending on the considered location. The good agreement between the simulation data and field data gathered on real systems enabled the validation of the models used in this study. (author)

  8. Modelling and analysis of a novel compressed air energy storage system for trigeneration based on electrical energy peak load shifting

    International Nuclear Information System (INIS)

    Lv, Song; He, Wei; Zhang, Aifeng; Li, Guiqiang; Luo, Bingqing; Liu, Xianghua

    2017-01-01

    Highlights: • A new CAES system for trigeneration based on electrical peak load shifting is proposed. • The theoretical models and the thermodynamics process are established and analyzed. • The relevant parameters influencing its performance have been discussed and optimized. • A novel energy and economic evaluation methods is proposed to evaluate the performance of the system. - Abstract: The compressed air energy storage (CAES) has made great contribution to both electricity and renewable energy. In the pursuit of reduced energy consumption and relieving power utility pressure effectively, a novel trigeneration system based on CAES for cooling, heating and electricity generation by electrical energy peak load shifting is proposed in this paper. The cooling power is generated by the direct expansion of compressed air, and the heating power is recovered in the process of compression and storage. Based on the working principle of the typical CAES, the theoretical analysis of the thermodynamic system models are established and the characteristics of the system are analyzed. A novel method used to evaluate energy and economic performance is proposed. A case study is conducted, and the economic-social and technical feasibility of the proposed system are discussed. The results show that the trigeneration system works efficiently at relatively low pressure, and the efficiency is expected to reach about 76.3% when air is compressed and released by 15 bar. The annual monetary cost saving annually is about 53.9%. Moreover, general considerations about the proposed system are also presented.

  9. Solar optics-based active panel for solar energy storage and disinfection of greywater.

    Science.gov (United States)

    Lee, W; Song, J; Son, J H; Gutierrez, M P; Kang, T; Kim, D; Lee, L P

    2016-09-01

    Smart city and innovative building strategies are becoming increasingly more necessary because advancing a sustainable building system is regarded as a promising solution to overcome the depleting water and energy. However, current sustainable building systems mainly focus on energy saving and miss a holistic integration of water regeneration and energy generation. Here, we present a theoretical study of a solar optics-based active panel (SOAP) that enables both solar energy storage and photothermal disinfection of greywater simultaneously. Solar collector efficiency of energy storage and disinfection rate of greywater have been investigated. Due to the light focusing by microlens, the solar collector efficiency is enhanced from 25% to 65%, compared to that without the microlens. The simulation of greywater sterilization shows that 100% disinfection can be accomplished by our SOAP for different types of bacteria including Escherichia coli . Numerical simulation reveals that our SOAP as a lab-on-a-wall system can resolve the water and energy problem in future sustainable building systems.

  10. Carbon-Based Functional Materials Derived from Waste for Water Remediation and Energy Storage.

    Science.gov (United States)

    Ma, Qinglang; Yu, Yifu; Sindoro, Melinda; Fane, Anthony G; Wang, Rong; Zhang, Hua

    2017-04-01

    Carbon-based functional materials hold the key for solving global challenges in the areas of water scarcity and the energy crisis. Although carbon nanotubes (CNTs) and graphene have shown promising results in various fields of application, their high preparation cost and low production yield still dramatically hinder their wide practical applications. Therefore, there is an urgent call for preparing carbon-based functional materials from low-cost, abundant, and sustainable sources. Recent innovative strategies have been developed to convert various waste materials into valuable carbon-based functional materials. These waste-derived carbon-based functional materials have shown great potential in many applications, especially as sorbents for water remediation and electrodes for energy storage. Here, the research progress in the preparation of waste-derived carbon-based functional materials is summarized, along with their applications in water remediation and energy storage; challenges and future research directions in this emerging research field are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Energy Storage and Retrieval

    Indian Academy of Sciences (India)

    Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 6. Energy Storage and Retrieval The Secondary Battery Route. A K Shukla P Vishnu Kamath.

  12. A Flywheel Energy Storage System Based on a Doubly Fed Induction Machine and Battery for Microgrid Control

    Directory of Open Access Journals (Sweden)

    Thai-Thanh Nguyen

    2015-06-01

    Full Text Available Microgrids are eco-friendly power systems because they use renewable sources such as solar and wind power as the main power source. However, the stochastic nature of wind and solar power is a considerable challenge for the efficient operation of microgrids. Microgrid operations have to satisfy quality requirements in terms of the frequency and voltage. To overcome these problems, energy storage systems for short- and long-term storage are used with microgrids. Recently, the use of short-term energy storage systems such as flywheels has attracted significant interest as a potential solution to this problem. Conventional flywheel energy storage systems exhibit only one control mode during operation: either smoothing wind power control or frequency control. In this paper, we propose a new flywheel energy storage system based on a doubly fed induction machine and a battery for use with microgrids. The new flywheel energy storage system can be used not only to mitigate wind power fluctuations, but also to control the frequency as well as the voltage of the microgrid during islanded operation. The performance of the proposed flywheel energy storage system is investigated through various simulations using MATLAB/Simulink software. In addition, a conventional flywheel energy storage system based on a doubly fed induction machine is simulated and its performance compared with that of the proposed one.

  13. Complex Nanostructures from Materials based on Metal-Organic Frameworks for Electrochemical Energy Storage and Conversion.

    Science.gov (United States)

    Guan, Bu Yuan; Yu, Xin Yao; Wu, Hao Bin; Lou, Xiong Wen David

    2017-12-01

    Metal-organic frameworks (MOFs) have drawn tremendous attention because of their abundant diversity in structure and composition. Recently, there has been growing research interest in deriving advanced nanomaterials with complex architectures and tailored chemical compositions from MOF-based precursors for electrochemical energy storage and conversion. Here, a comprehensive overview of the synthesis and energy-related applications of complex nanostructures derived from MOF-based precursors is provided. After a brief summary of synthetic methods of MOF-based templates and their conversion to desirable nanostructures, delicate designs and preparation of complex architectures from MOFs or their composites are described in detail, including porous structures, single-shelled hollow structures, and multishelled hollow structures, as well as other unusual complex structures. Afterward, their applications are discussed as electrode materials or catalysts for lithium-ion batteries, hybrid supercapacitors, water-splitting devices, and fuel cells. Lastly, the research challenges and possible development directions of complex nanostructures derived from MOF-based-templates for electrochemical energy storage and conversion applications are outlined. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Technical and economic analysis on grid-connected wind farm based on hybrid energy storage system and distributed generators

    Science.gov (United States)

    Zhang, Xinhua; Zhou, Zhongkang; Chen, Xiaochun; Song, Jishuang; Shi, Maolin

    2017-05-01

    system is proposed based on NaS battery and lithium ion battery, that the former is the main large scale energy storage technology world-widely used and developed and the latter is a flexible way to have both power and energy capacities. The hybrid energy storage system, which takes advantage of the two complementary technologies to provide large power and energy capacities, is chosen to do an evaluation of econom ical-environmental based on critical excess electricity production (CEEP), CO2 emission, annual total costs calculated on the specific given condition using Energy PLAN software. The result shows that hybrid storage system has strengths in environmental benefits and also can absorb more discarded wind power than single storage system and is a potential way to push forward the application of wind power and even other types of renewable energy resources.

  15. Energy managemant through PCM based thermal storage system for building air-conditioning: Tidel Park, Chennai

    International Nuclear Information System (INIS)

    Nallusamy, N.; Sampath, S.; Velraj, R.

    2006-01-01

    Many modern building are designed for air-conditioning and the amount of electrical energy required for providing air-conditioning can be very significant especially in the tropics. Conservation of energy is major concern to improve the overall efficiency of the system. Integration is energy storage with the conventional system gives a lot of potential for energy saving and long-term economics. Thermal energy storage systems can improve energy management and help in matching supply and demand patterns. In the present work, a detailed study has been done on the existing thermal energy storage system used in the air-conditioning system in Tidel Park, Chennai. The present study focuses on the cool energy storage system. The modes of operation and advantages of such a system for energy management are highlighted. The reason for the adoption of combined storage system and the size of the storage medium in the air-conditioning plant are analyzed. The possibility of using this concept in other cooling and heating applications, such as storage type solar water heating system, has been explored

  16. Nanoarchitectured graphene-based supercapacitors for next-generation energy-storage applications.

    Science.gov (United States)

    Salunkhe, Rahul R; Lee, Ying-Hui; Chang, Kuo-Hsin; Li, Jing-Mei; Simon, Patrice; Tang, Jing; Torad, Nagy L; Hu, Chi-Chang; Yamauchi, Yusuke

    2014-10-20

    Tremendous development in the field of portable electronics and hybrid electric vehicles has led to urgent and increasing demand in the field of high-energy storage devices. In recent years, many research efforts have been made for the development of more efficient energy-storage devices such as supercapacitors, batteries, and fuel cells. In particular, supercapacitors have great potential to meet the demands of both high energy density and power density in many advanced technologies. For the last half decade, graphene has attracted intense research interest for electrical double-layer capacitor (EDLC) applications. The unique electronic, thermal, mechanical, and chemical characteristics of graphene, along with the intrinsic benefits of a carbon material, make it a promising candidate for supercapacitor applications. This Review focuses on recent research developments in graphene-based supercapacitors, including doped graphene, activated graphene, graphene/metal oxide composites, graphene/polymer composites, and graphene-based asymmetric supercapacitors. The challenges and prospects of graphene-based supercapacitors are also discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Energy Storage Project

    Science.gov (United States)

    Mercer, Carolyn R.; Jankovsky, Amy L.; Reid, Concha M.; Miller, Thomas B.; Hoberecht, Mark A.

    2011-01-01

    NASA's Exploration Technology Development Program funded the Energy Storage Project to develop battery and fuel cell technology to meet the expected energy storage needs of the Constellation Program for human exploration. Technology needs were determined by architecture studies and risk assessments conducted by the Constellation Program, focused on a mission for a long-duration lunar outpost. Critical energy storage needs were identified as batteries for EVA suits, surface mobility systems, and a lander ascent stage; fuel cells for the lander and mobility systems; and a regenerative fuel cell for surface power. To address these needs, the Energy Storage Project developed advanced lithium-ion battery technology, targeting cell-level safety and very high specific energy and energy density. Key accomplishments include the development of silicon composite anodes, lithiated-mixed-metal-oxide cathodes, low-flammability electrolytes, and cell-incorporated safety devices that promise to substantially improve battery performance while providing a high level of safety. The project also developed "non-flow-through" proton-exchange-membrane fuel cell stacks. The primary advantage of this technology set is the reduction of ancillary parts in the balance-of-plant--fewer pumps, separators and related components should result in fewer failure modes and hence a higher probability of achieving very reliable operation, and reduced parasitic power losses enable smaller reactant tanks and therefore systems with lower mass and volume. Key accomplishments include the fabrication and testing of several robust, small-scale nonflow-through fuel cell stacks that have demonstrated proof-of-concept. This report summarizes the project s goals, objectives, technical accomplishments, and risk assessments. A bibliography spanning the life of the project is also included.

  18. Design Considerations for Gan-Based Microinverter for Energy Storage Integration Into Ac Grid

    Science.gov (United States)

    Kroics, K.; Zakis, J.; Suzdalenko, A.; Husev, O.

    2017-10-01

    A full bridge converter with electrolytic capacitor on the dc bus is a widely used approach for a single phase interface for renewable energy source generation or energy storage integration in the utility grid. New wide bandgap devices enable higher switching frequency, higher efficiency and higher power density. In the paper, the authors introduce the challenges associated with an increase in switching frequency of a single phase inverter and implementation of wide bandgap GaN-based transistors instead of traditional Si-based transistors. The low gate threshold voltage of GaN transistor and unique reverse conduction behaviour require different driving circuit. The design of the driver circuit and other practical issues are analysed in the paper. The paper also presents some practical results. The research results can be useful to avoid mistakes by designing GaN-based power converters as these devices become increasingly interesting for commercial applications.

  19. Design Considerations for Gan-Based Microinverter for Energy Storage Integration Into Ac Grid

    Directory of Open Access Journals (Sweden)

    Kroics K.

    2017-10-01

    Full Text Available A full bridge converter with electrolytic capacitor on the dc bus is a widely used approach for a single phase interface for renewable energy source generation or energy storage integration in the utility grid. New wide bandgap devices enable higher switching frequency, higher efficiency and higher power density. In the paper, the authors introduce the challenges associated with an increase in switching frequency of a single phase inverter and implementation of wide bandgap GaN-based transistors instead of traditional Si-based transistors. The low gate threshold voltage of GaN transistor and unique reverse conduction behaviour require different driving circuit. The design of the driver circuit and other practical issues are analysed in the paper. The paper also presents some practical results. The research results can be useful to avoid mistakes by designing GaN-based power converters as these devices become increasingly interesting for commercial applications.

  20. The future cost of electrical energy storage based on experience rates

    Science.gov (United States)

    Schmidt, O.; Hawkes, A.; Gambhir, A.; Staffell, I.

    2017-08-01

    Electrical energy storage could play a pivotal role in future low-carbon electricity systems, balancing inflexible or intermittent supply with demand. Cost projections are important for understanding this role, but data are scarce and uncertain. Here, we construct experience curves to project future prices for 11 electrical energy storage technologies. We find that, regardless of technology, capital costs are on a trajectory towards US$340 ± 60 kWh-1 for installed stationary systems and US$175 ± 25 kWh-1 for battery packs once 1 TWh of capacity is installed for each technology. Bottom-up assessment of material and production costs indicates this price range is not infeasible. Cumulative investments of US$175-510 billion would be needed for any technology to reach 1 TWh deployment, which could be achieved by 2027-2040 based on market growth projections. Finally, we explore how the derived rates of future cost reduction influence when storage becomes economically competitive in transport and residential applications. Thus, our experience-curve data set removes a barrier for further study by industry, policymakers and academics.

  1. Analysis of DC/DC Converter Efficiency for Energy Storage System Based on Bidirectional Fuel Cells

    DEFF Research Database (Denmark)

    Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    interface to the grid. In power electronics, the converter efficiency is characterized at fixed operating voltage for various output power. This type of characterization is not suitable for fuel cells, since as the power from the fuel cell increases, the cell voltage decreases. This paper analyses how......Renewable energy sources are fluctuating depending on the availability of the energy source. For this reason, energy storage is becoming more important and bidirectional fuel cells represent an attractive technology. Fuel cells require highcurrent low-voltage dc-dc or dc-ac converters as power...... the fuel cell I-V characteristics influences the power electronics converter efficiency and their consequence on the overall system. A loaddependent efficiency curve is presented based on experimental results from a 6 kW dc-dc converter prototype including the most suitable control strategy which maximizes...

  2. Energy storage in evaporated brine

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, R. Ian

    2010-09-15

    We propose storage of electrical energy in brine solutions by using the energy to enhance natural evaporation. Using properties of existing industrial evaporation technologies and estimates of power regeneration from brine by pressure retarded osmosis, efficiency near 100% is calculated. Modelling indicates that systems ranging from 50kW to 50MW output may be practical, with storage capacities of hours to days. The method appears to have potential to be economically competitive with other technologies over a wide range of capacity. It may present a large new application area that could aid the development of salinity-based power generation technology.

  3. Maui energy storage study.

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, James; Bhatnagar, Dhruv; Karlson, Benjamin

    2012-12-01

    This report investigates strategies to mitigate anticipated wind energy curtailment on Maui, with a focus on grid-level energy storage technology. The study team developed an hourly production cost model of the Maui Electric Company (MECO) system, with an expected 72 MW of wind generation and 15 MW of distributed photovoltaic (PV) generation in 2015, and used this model to investigate strategies that mitigate wind energy curtailment. It was found that storage projects can reduce both wind curtailment and the annual cost of producing power, and can do so in a cost-effective manner. Most of the savings achieved in these scenarios are not from replacing constant-cost diesel-fired generation with wind generation. Instead, the savings are achieved by the more efficient operation of the conventional units of the system. Using additional storage for spinning reserve enables the system to decrease the amount of spinning reserve provided by single-cycle units. This decreases the amount of generation from these units, which are often operated at their least efficient point (at minimum load). At the same time, the amount of spinning reserve from the efficient combined-cycle units also decreases, allowing these units to operate at higher, more efficient levels.

  4. Investigations on thermochemical energy storage based on manganese-iron oxide in a lab-scale reactor

    Science.gov (United States)

    Wokon, Michael; Bauer, Thomas; Linder, Marc

    2017-06-01

    Thermochemical energy storage based on reversible redox reactions of metal oxides constitutes a promising concept to store thermal energy at high temperatures, which renders those storage materials specifically attractive for the implementation in solar tower plants. Only a few experimental studies on lab-scale storage reactors working with metal oxides have been reported. Therefore, an investigation of granular metal oxides in a packed bed storage reactor is presented with regard to thermal storage characteristics and prevalent limitations influencing thermal charging and discharging. Pure manganese oxide and manganese-iron oxide with a Mn/Fe molar ratio of 2:1 are compared as potential storage materials. The main advantages of the binary oxide are derived from the experimental results. Moreover, heat transfer between solid and gas has been identified to be the main limiting factor for the onward reactions of manganese-iron oxide under the applied experimental conditions.

  5. Energy storage financing :

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Richard

    2016-08-01

    Project financing is emerging as the linchpin for the future health, direction, and momentum of the energy storage industry. Market leaders have so far relied on selffunding or captive lending arrangements to fund projects. New lenders are proceeding hesitantly as they lack a full understanding of the technology, business, and credit risks involved in this rapidly changing market. The U.S. Department of Energy is poised to play a critical role in expanding access to capital by reducing the barriers to entry for new lenders, and providing trusted analytical benchmarks to better judge and price the risk in systematic ways.

  6. Energy Coordinative Optimization of Wind-Storage-Load Microgrids Based on Short-Term Prediction

    Directory of Open Access Journals (Sweden)

    Changbin Hu

    2015-02-01

    Full Text Available According to the topological structure of wind-storage-load complementation microgrids, this paper proposes a method for energy coordinative optimization which focuses on improvement of the economic benefits of microgrids in the prediction framework. First of all, the external characteristic mathematical model of distributed generation (DG units including wind turbines and storage batteries are established according to the requirements of the actual constraints. Meanwhile, using the minimum consumption costs from the external grid as the objective function, a grey prediction model with residual modification is introduced to output the predictive wind turbine power and load at specific periods. Second, based on the basic framework of receding horizon optimization, an intelligent genetic algorithm (GA is applied to figure out the optimum solution in the predictive horizon for the complex non-linear coordination control model of microgrids. The optimum results of the GA are compared with the receding solution of mixed integer linear programming (MILP. The obtained results show that the method is a viable approach for energy coordinative optimization of microgrid systems for energy flow and reasonable schedule. The effectiveness and feasibility of the proposed method is verified by examples.

  7. Porphyrin-Based Symmetric Redox-Flow Batteries towards Cold-Climate Energy Storage.

    Science.gov (United States)

    Ma, Ting; Pan, Zeng; Miao, Licheng; Chen, Chengcheng; Han, Mo; Shang, Zhenfeng; Chen, Jun

    2018-03-12

    Electrochemical energy storage with redox-flow batteries (RFBs) under subzero temperature is of great significance for the use of renewable energy in cold regions. However, RFBs are generally used above 10 °C. Herein we present non-aqueous organic RFBs based on 5,10,15,20-tetraphenylporphyrin (H 2 TPP) as a bipolar redox-active material (anode: [H 2 TPP] 2- /H 2 TPP, cathode: H 2 TPP/[H 2 TPP] 2+ ) and a Y-zeolite-poly(vinylidene fluoride) (Y-PVDF) ion-selective membrane with high ionic conductivity as a separator. The constructed RFBs exhibit a high volumetric capacity of 8.72 Ah L -1 with a high voltage of 2.83 V and excellent cycling stability (capacity retention exceeding 99.98 % per cycle) in the temperature range between 20 and -40 °C. Our study highlights principles for the design of RFBs that operate at low temperatures, thus offering a promising approach to electrochemical energy storage under cold-climate conditions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Modeling a photovoltaic energy storage system based on super capacitor, simulation and evaluation of experimental performance

    Science.gov (United States)

    Ben Fathallah, Mohamed Ali; Ben Othman, Afef; Besbes, Mongi

    2018-02-01

    Photovoltaic energy is very important to meet the consumption needs of electrical energy in remote areas and for other applications. Energy storage systems are essential to avoid the intermittent production of photovoltaic energy and to cover peaks in energy demand. The super capacitor, also known as electrochemical double layer capacitor, is a storage device which has a very high power density compared to conventional battery and is capable of storing a large amount of electrical energy in short time periods, which reflects its interest to be used for the storage of photovoltaic energy. From this principle, this paper represents a three-branch RC model of super capacitor to describe its different dynamics of operation during the charging, discharging and rest phases. After having validated the good functioning of this model with the experimental study of Zubieta, The super capacitor performance has been demonstrated and compared with a conventional battery in a photovoltaic converter chain to power AC machine.

  9. Conductive Microporous Covalent Triazine-Based Framework for High-Performance Electrochemical Capacitive Energy Storage.

    Science.gov (United States)

    Li, Yajuan; Zheng, Shuanghao; Liu, Xue; Li, Pan; Sun, Lei; Yang, Ruixia; Wang, Sen; Wu, Zhong-Shuai; Bao, Xinhe; Deng, Wei-Qiao

    2017-11-14

    Nitrogen-enriched porous nanocarbon, graphene, and conductive polymers attract increasing attention for application in supercapacitors. However, electrode materials with a large specific surface area (SSA) and a high nitrogen doping concentration, which is needed for excellent supercapacitors, has not been achieved thus far. Herein, we developed a class of tetracyanoquinodimethane-derived conductive microporous covalent triazine-based frameworks (TCNQ-CTFs) with both high nitrogen content (>8 %) and large SSA (>3600 m 2  g -1 ). These CTFs exhibited excellent specific capacitances with the highest value exceeding 380 F g -1 , considerable energy density of 42.8 Wh kg -1 , and remarkable cycling stability without any capacitance degradation after 10 000 cycles. This class of CTFs should hold a great potential as high-performance electrode material for electrochemical energy-storage systems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. A Review of Energy Storage Technologies

    DEFF Research Database (Denmark)

    Connolly, David

    2010-01-01

    A brief examination into the energy storage techniques currently available for the integration of fluctuating renewable energy was carried out. These included Pumped Hydroelectric Energy Storage (PHES), Underground Pumped Hydroelectric Energy Storage (UPHES), Compressed Air Energy Storage (CAES...

  11. From Carbon-Based Nanotubes to Nanocages for Advanced Energy Conversion and Storage.

    Science.gov (United States)

    Wu, Qiang; Yang, Lijun; Wang, Xizhang; Hu, Zheng

    2017-02-21

    Carbon-based nanomaterials have been the focus of research interests in the past 30 years due to their abundant microstructures and morphologies, excellent properties, and wide potential applications, as landmarked by 0D fullerene, 1D nanotubes, and 2D graphene. With the availability of high specific surface area (SSA), well-balanced pore distribution, high conductivity, and tunable wettability, carbon-based nanomaterials are highly expected as advanced materials for energy conversion and storage to meet the increasing demands for clean and renewable energies. In this context, attention is usually attracted by the star material of graphene in recent years. In this Account, we overview our studies on carbon-based nanotubes to nanocages for energy conversion and storage, including their synthesis, performances, and related mechanisms. The two carbon nanostructures have the common features of interior cavity, high conductivity, and easy doping but much different SSAs and pore distributions, leading to different performances. We demonstrated a six-membered-ring-based growth mechanism of carbon nanotubes (CNTs) with benzene precursor based on the structural similarity of the benzene ring to the building unit of CNTs. By this mechanism, nitrogen-doped CNTs (NCNTs) with homogeneous N distribution and predominant pyridinic N were obtained with pyridine precursor, providing a new kind of support for convenient surface functionalization via N-participation. Accordingly, various transition-metal nanoparticles were directly immobilized onto NCNTs without premodification. The so-constructed catalysts featured high dispersion, narrow size distribution and tunable composition, which presented superior catalytic performances for energy conversions, for example, the oxygen reduction reaction (ORR) and methanol oxidation in fuel cells. With the advent of the new field of carbon-based metal-free electrocatalysts, we first extended ORR catalysts from the electron-rich N-doped to the

  12. MIC: Magnetically Deployable Structures for Power, Propulsion, Processing, Habitats and Energy Storage at Manned Lunar Bases

    Science.gov (United States)

    Powell, James; Maise, George; Paniagua, John; Rather, John

    2007-01-01

    MIC (Magnetically Inflated Cables) is a new approach for robotically erecting very large, strong, rigid, and ultra-lightweight structures in space. MIC structures use a network of high current (SC) cables with attached high tensile strength Kevlar or Spectra tethers. MIC is launched as a compact package of coiled SC cables and tethers on a conventional launch vehicle. Once in space the SC cables are electrically energized. The resultant strong outwards magnetic forces expand them and the restraining tethers into a large structure, which can be 100's of meters in size. MIC structures can be configured for many different applications, including solar electric generation, solar thermal propulsion, energy storage, large space telescopes, magnetic shielding for astronauts, etc. The MIC technology components, including high temperature superconductors (HTS), thermal insulation, high strength tethers, and cryogenic refrigerators all exist commercially. Refrigeration requirements are very modest, on the order of 100 watts thermal per kilometer of MIC cable, with an input electric power to the refrigeration system of ~5 kW(e) per km. baseline MIC designs are described for a manned lunar base, including: 1) a 1 MW(e) solar electric system, 2) a high Isp (~900 seconds) solar thermal tug to transport 30 ton payloads between the Earth and the Moon, 3) a 2000 Megajoule electric energy storage system for peaking and emergency power, and 4) a large (~1 km) space telescope.

  13. Building Energy Storage Panel Based on Paraffin/Expanded Perlite: Preparation and Thermal Performance Study

    Directory of Open Access Journals (Sweden)

    Xiangfei Kong

    2016-01-01

    Full Text Available This study is focused on the preparation and performance of a building energy storage panel (BESP. The BESP was fabricated through a mold pressing method based on phase change material particle (PCMP, which was prepared in two steps: vacuum absorption and surface film coating. Firstly, phase change material (PCM was incorporated into expanded perlite (EP through a vacuum absorption method to obtain composite PCM; secondly, the composite PCM was immersed into the mixture of colloidal silica and organic acrylate, and then it was taken out and dried naturally. A series of experiments, including differential scanning calorimeter (DSC, scanning electron microscope (SEM, best matching test, and durability test, have been conducted to characterize and analyze the thermophysical property and reliability of PCMP. Additionally, the thermal performance of BESP was studied through a dynamic thermal property test. The results have showed that: (1 the surface film coating procedure can effectively solve the leakage problem of composite phase change material prepared by vacuum impregnation; (2 the optimum adsorption ratio for paraffin and EP was 52.5:47.5 in mass fraction, and the PCMP has good thermal properties, stability, and durability; and (3 in the process of dynamic thermal performance test, BESP have low temperature variation, significant temperature lagging, and large heat storage ability, which indicated the potential of BESP in the application of building energy efficiency.

  14. Building Energy Storage Panel Based on Paraffin/Expanded Perlite: Preparation and Thermal Performance Study.

    Science.gov (United States)

    Kong, Xiangfei; Zhong, Yuliang; Rong, Xian; Min, Chunhua; Qi, Chengying

    2016-01-25

    This study is focused on the preparation and performance of a building energy storage panel (BESP). The BESP was fabricated through a mold pressing method based on phase change material particle (PCMP), which was prepared in two steps: vacuum absorption and surface film coating. Firstly, phase change material (PCM) was incorporated into expanded perlite (EP) through a vacuum absorption method to obtain composite PCM; secondly, the composite PCM was immersed into the mixture of colloidal silica and organic acrylate, and then it was taken out and dried naturally. A series of experiments, including differential scanning calorimeter (DSC), scanning electron microscope (SEM), best matching test, and durability test, have been conducted to characterize and analyze the thermophysical property and reliability of PCMP. Additionally, the thermal performance of BESP was studied through a dynamic thermal property test. The results have showed that: (1) the surface film coating procedure can effectively solve the leakage problem of composite phase change material prepared by vacuum impregnation; (2) the optimum adsorption ratio for paraffin and EP was 52.5:47.5 in mass fraction, and the PCMP has good thermal properties, stability, and durability; and (3) in the process of dynamic thermal performance test, BESP have low temperature variation, significant temperature lagging, and large heat storage ability, which indicated the potential of BESP in the application of building energy efficiency.

  15. Monitoring innovation in electrochemical energy storage technologies: A patent-based approach

    International Nuclear Information System (INIS)

    Mueller, Simon C.; Sandner, Philipp G.; Welpe, Isabell M.

    2015-01-01

    important patents and organizations for relevant candidate technologies. Our study underlines that electrochemical storage, and in particular lithium-based technologies, will play an increasingly important role in future energy systems

  16. Flywheel energy storage workshop

    Energy Technology Data Exchange (ETDEWEB)

    O`Kain, D.; Carmack, J. [comps.

    1995-12-31

    Since the November 1993 Flywheel Workshop, there has been a major surge of interest in Flywheel Energy Storage. Numerous flywheel programs have been funded by the Advanced Research Projects Agency (ARPA), by the Department of Energy (DOE) through the Hybrid Vehicle Program, and by private investment. Several new prototype systems have been built and are being tested. The operational performance characteristics of flywheel energy storage are being recognized as attractive for a number of potential applications. Programs are underway to develop flywheels for cars, buses, boats, trains, satellites, and for electric utility applications such as power quality, uninterruptible power supplies, and load leveling. With the tremendous amount of flywheel activity during the last two years, this workshop should again provide an excellent opportunity for presentation of new information. This workshop is jointly sponsored by ARPA and DOE to provide a review of the status of current flywheel programs and to provide a forum for presentation of new flywheel technology. Technology areas of interest include flywheel applications, flywheel systems, design, materials, fabrication, assembly, safety & containment, ball bearings, magnetic bearings, motor/generators, power electronics, mounting systems, test procedures, and systems integration. Information from the workshop will help guide ARPA & DOE planning for future flywheel programs. This document is comprised of detailed viewgraphs.

  17. Solar energy storage

    CERN Document Server

    Sorensen, Bent

    2015-01-01

    While solar is the fastest-growing energy source in the world, key concerns around solar power's inherent variability threaten to de-rail that scale-up . Currently, integration of intermittent solar resources into the grid creates added complication to load management, leading some utilities to reject it altogether, while other operators may penalize the producers via rate increases or force solar developers to include storage devices on-site to smooth out power delivery at the point of production. However these efforts at mitigation unfold, it is increasingly clear to parties on all sides th

  18. A GIS Based 3D Online Decision Assistance System for Underground Energy Storage in Northern Germany

    Science.gov (United States)

    Nolde, M.; Schwanebeck, M.; Biniyaz, E.; Duttmann, R.

    2014-12-01

    We would like to present a GIS-based 3D online decision assistance system for underground energy storage. Its aim is to support the local land use planning authorities through pre-selection of possible sites for thermal, electrical and substantial underground energy storages. Since the extension of renewable energies has become legal requirement in Germany, the underground storing of superfluously produced green energy (such as during a heavy wind event) in the form of compressed air, gas or heated water has become increasingly important. However, the selection of suitable sites is a complex task. The assistance system uses data of geological features such as rock layers, salt caverns and faults enriched with attribute data such as rock porosity and permeability. This information is combined with surface data of the existing energy infrastructure, such as locations of wind and biogas stations, power line arrangement and cable capacity, and energy distribution stations. Furthermore, legal obligations such as protected areas on the surface and current underground mining permissions are used for the decision finding process. Not only the current situation but also prospective scenarios, such as expected growth in produced amount of energy are incorporated in the system. The decision process is carried out via the 'Analytic Hierarchy Process' (AHP) methodology of the 'Multi Object Decision Making' (MODM) approach. While the process itself is completely automated, the user has full control of the weighting of the different factors via the web interface. The system is implemented as an online 3D server GIS environment, with no software needed to be installed on the user side. The results are visualized as interactive 3d graphics. The implementation of the assistance system is based exclusively on free and open source software, and utilizes the 'Python' programming language in combination with current web technologies, such as 'HTML5', 'CSS3' and 'JavaScript'. It is

  19. Multimaterial 3D Printing of Graphene-Based Electrodes for Electrochemical Energy Storage Using Thermoresponsive Inks.

    Science.gov (United States)

    Rocha, Victoria G; García-Tuñón, Esther; Botas, Cristina; Markoulidis, Foivos; Feilden, Ezra; D'Elia, Eleonora; Ni, Na; Shaffer, Milo; Saiz, Eduardo

    2017-10-25

    The current lifestyles, increasing population, and limited resources result in energy research being at the forefront of worldwide grand challenges, increasing the demand for sustainable and more efficient energy devices. In this context, additive manufacturing brings the possibility of making electrodes and electrical energy storage devices in any desired three-dimensional (3D) shape and dimensions, while preserving the multifunctional properties of the active materials in terms of surface area and conductivity. This paves the way to optimized and more efficient designs for energy devices. Here, we describe how three-dimensional (3D) printing will allow the fabrication of bespoke devices, with complex geometries, tailored to fit specific requirements and applications, by designing water-based thermoresponsive inks to 3D-print different materials in one step, for example, printing the active material precursor (reduced chemically modified graphene (rCMG)) and the current collector (copper) for supercapacitors or anodes for lithium-ion batteries. The formulation of thermoresponsive inks using Pluronic F127 provides an aqueous-based, robust, flexible, and easily upscalable approach. The devices are designed to provide low resistance interface, enhanced electrical properties, mechanical performance, packing of rCMG, and low active material density while facilitating the postprocessing of the multicomponent 3D-printed structures. The electrode materials are selected to match postprocessing conditions. The reduction of the active material (rCMG) and sintering of the current collector (Cu) take place simultaneously. The electrochemical performance of the rCMG-based self-standing binder-free electrode and the two materials coupled rCMG/Cu printed electrode prove the potential of multimaterial printing in energy applications.

  20. Preparation and characterization of sepiolite-based phase change material nanocomposites for thermal energy storage

    International Nuclear Information System (INIS)

    Konuklu, Yeliz; Ersoy, Orkun

    2016-01-01

    Highlights: • Sepiolite-based phase change material nanocomposites were prepared. • An easy direct impregnation process was used. • This paper is one of the first study about sepiolite-based phase change material nanocomposites. • Influence of PCM type on thermal properties of nanocomposites was reported. - Abstract: This paper is one of the first study about the preparation and characterization of sepiolite-based phase change material nanocomposites for thermal energy storage applications. Sepiolite is an important natural fibrous raw material. Nanoscale fibrous tubular structure of sepiolite becomes important in nanocomposite preparation. In this study, sepiolite/paraffin and sepiolite/decanoic acid nanocomposites were manufactured by the direct impregnation method. By the preparation of nanocomposites, PCM move in tubular channels of sepiolite, phase changing occurs in these tubes and surface area increases like as in microencapsulation. The structure and properties of nanocomposites PCMs (CPCM) have been characterized via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The SEM results prove the successful preparation of phase change material/sepiolite nanocomposites and point out that the fibers of sepiolite is modified with phase change materials in the nanocomposite. The phase change enthalpies of melting and freezing were about 62.08 J/g and −62.05 J/g for sepiolite/paraffin nanocomposites and 35.69 J/g and −34.55 J/g for sepiolite/decanoic acid nanocomposites, respectively. The results show that PCM/sepiolite nanocomposites were prepared successfully and their properties are very suitable for thermal energy storage applications.

  1. Fatty acid esters-based composite phase change materials for thermal energy storage in buildings

    International Nuclear Information System (INIS)

    Sarı, Ahmet; Karaipekli, Ali

    2012-01-01

    In this study, fatty acid esters-based composite phase change materials (PCMs) for thermal energy storage were prepared by blending erythritol tetrapalmitate (ETP) and erythritol tetrastearate (ETS) with diatomite and expanded perlite (EP). The maximum incorporation percentage for ETP and ETS into diatomite and EP was found to be 57 wt% and 62 wt%, respectively without melted PCM seepage from the composites. The morphologies and compatibilities of the composite PCMs were structurally characterized using scanning electron microscope (SEM) and Fourier transformation infrared (FT–IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by differential scanning calorimetry (DSC) analysis. The DSC analyses results indicated that the composite PCMs were good candidates for building applications in terms of their large latent heat values and suitable phase change temperatures. The thermal cycling test including 1000 melting and freezing cycling showed that composite PCMs had good thermal reliability and chemical stability. TG analysis revealed that the composite PCMs had good thermal durability above their working temperature ranges. Moreover, in order to improve the thermal conductivity of the composite PCMs, the expanded graphite (EG) was added to them at different mass fractions (2%, 5%, and 10%). The best results were obtained for the composite PCMs including 5wt% EG content in terms of the increase in thermal conductivity values and the decrease amount in latent heat capacity. The improvement in thermal conductivity values of ETP/Diatomite, ETS/Diatomite, ETP/EP and ETS/EP were found to be about 68%, 57%, 73% and 75%, respectively. Highlights: ► Fatty acid esters-based composite PCMs were prepared by blending ETP and ETS with diatomite and expanded perlite. ► The composite PCMs were characterized by using SEM, FT–IR, DSC and TG analysis methods. ► The DSC results indicated that the composites PCMs had good thermal

  2. Stability Analysis of DC Distribution Systems with Droop-Based Charge Sharing on Energy Storage Devices

    Directory of Open Access Journals (Sweden)

    Despoina I. Makrygiorgou

    2017-03-01

    Full Text Available Direct current (DC distribution systems and DC microgrids are becoming a reliable and efficient alternative energy system, compatible with the DC nature of most of the distributed energy resources (DERs, storage devices and loads. The challenging problem of redesigning an autonomous DC-grid system in view of using energy storage devices to balance the power produced and absorbed, by applying simple decentralized controllers on the electronic power interfaces, is investigated in this paper. To this end, a complete nonlinear DC-grid model has been deployed that includes different DC-DERs, two controlled parallel battery branches, and different varying DC loads. Since many loads in modern distribution systems are connected through power converters, both constant power loads and simple resistive loads are considered in parallel. Within this system, suitable cascaded controllers on the DC/DC power converter interfaces to the battery branches are proposed, in a manner that ensures stability and charge sharing between the two branches at the desired ratio. To achieve this task, inner-loop current controllers are combined with outer-loop voltage, droop-based controllers. The proportional-integral (PI inner-loop current controllers include damping terms and are fully independent from the system parameters. The controller scheme is incorporated into the system model and a globally valid nonlinear stability analysis is conducted; this differs from small-signal linear methods that are valid only for specific systems, usually via eigenvalue investigations. In the present study, under the virtual cost of applying advanced Lyapunov techniques on the entire nonlinear system, a rigorous analysis is formulated to prove stability and convergence to the desired operation, regardless of the particular system characteristics. The theoretical results are evaluated by detailed simulations, with the system performance being very satisfactory.

  3. Robustness Improvement of Superconducting Magnetic Energy Storage System in Microgrids Using an Energy Shaping Passivity-Based Control Strategy

    Directory of Open Access Journals (Sweden)

    Rui Hou

    2017-05-01

    Full Text Available Superconducting magnetic energy storage (SMES systems, in which the proportional-integral (PI method is usually used to control the SMESs, have been used in microgrids for improving the control performance. However, the robustness of PI-based SMES controllers may be unsatisfactory due to the high nonlinearity and coupling of the SMES system. In this study, the energy shaping passivity (ESP-based control strategy, which is a novel nonlinear control based on the methodology of interconnection and damping assignment (IDA, is proposed for robustness improvement of SMES systems. A step-by-step design of the ESP-based method considering the robustness of SMES systems is presented. A comparative analysis of the performance between ESP-based and PI control strategies is shown. Simulation and experimental results prove that the ESP-based strategy achieves the stronger robustness toward the system parameter uncertainties than the conventional PI control. Besides, the use of ESP-based control method can reduce the eddy current losses of a SMES system due to the significant reduction of 2nd and 3rd harmonics of superconducting coil DC current.

  4. Simulation-based design of energy management system with storage battery for a refugee shelter in Japan

    Science.gov (United States)

    Kaji, K.; Zhang, J.; Horie, H.; Akimoto, H.; Tanaka, K.

    2013-12-01

    Since the massive earthquake hit eastern Japan in March, 2011, our team has participated in the recovery planning for Kesen Association, which is a group of cities in northeastern Japan. As one of our proposals for the recovery planning for the community, we are designing energy management system with renewable energy (RE) and storage batteries. Some public facilities in the area have been used as refugee shelters, but refugees had to put up with life without electricity for a while after the disaster. If RE generator and storage batteries are introduced into the facilities, it is possible to provide refugees with electricity. In this study, the sizes of photovoltaic (PV) appliances and storage batteries to be introduced into one public facility are optimized. The optimization is based on simulation, in which electric energy is managed by charge and discharge of storage battery.

  5. Simulation-based design of energy management system with storage battery for a refugee shelter in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Kaji, K.; Zhang, J.; Horie, H.; Tanaka, K. [Department of Technology Management for Innovation, Graduate School of Engineering, The University of Tokyo (Japan); Akimoto, H. [Korea Advanced Institute of Science and Technology (Korea, Republic of)

    2013-12-10

    Since the massive earthquake hit eastern Japan in March, 2011, our team has participated in the recovery planning for Kesen Association, which is a group of cities in northeastern Japan. As one of our proposals for the recovery planning for the community, we are designing energy management system with renewable energy (RE) and storage batteries. Some public facilities in the area have been used as refugee shelters, but refugees had to put up with life without electricity for a while after the disaster. If RE generator and storage batteries are introduced into the facilities, it is possible to provide refugees with electricity. In this study, the sizes of photovoltaic (PV) appliances and storage batteries to be introduced into one public facility are optimized. The optimization is based on simulation, in which electric energy is managed by charge and discharge of storage battery.

  6. Simulation-based design of energy management system with storage battery for a refugee shelter in Japan

    International Nuclear Information System (INIS)

    Kaji, K.; Zhang, J.; Horie, H.; Tanaka, K.; Akimoto, H.

    2013-01-01

    Since the massive earthquake hit eastern Japan in March, 2011, our team has participated in the recovery planning for Kesen Association, which is a group of cities in northeastern Japan. As one of our proposals for the recovery planning for the community, we are designing energy management system with renewable energy (RE) and storage batteries. Some public facilities in the area have been used as refugee shelters, but refugees had to put up with life without electricity for a while after the disaster. If RE generator and storage batteries are introduced into the facilities, it is possible to provide refugees with electricity. In this study, the sizes of photovoltaic (PV) appliances and storage batteries to be introduced into one public facility are optimized. The optimization is based on simulation, in which electric energy is managed by charge and discharge of storage battery

  7. Magnesium-based energy storage systems and methods having improved electrolytes

    Science.gov (United States)

    Liu, Tianbiao; Li, Guosheng; Liu, Jun; Shao, Yuyan

    2016-12-20

    Electrolytes for Mg-based energy storage devices can be formed from non-nucleophilic Mg.sup.2+ sources to provide outstanding electrochemical performance and improved electrophilic susceptibility compared to electrolytes employing nucleophilic sources. The instant electrolytes are characterized by high oxidation stability (up to 3.4 V vs Mg), improved electrophile compatibility and electrochemical reversibility (up to 100% coulombic efficiency). Synthesis of the Mg.sup.2+ electrolytes utilizes inexpensive and safe magnesium dihalides as non-nucleophilic Mg.sup.2+ sources in combination with Lewis acids, MR.sub.aX.sub.3-a (for 3.gtoreq.a.gtoreq.1). Furthermore, addition of free-halide-anion donors can improve the coulombic efficiency of Mg electrolytes from nucleophilic or non-nucleophilic Mg.sup.2+ sources.

  8. Levelised cost of storage for pumped heat energy storage in comparison with other energy storage technologies

    OpenAIRE

    Smallbone, A.; Jülch, V.; Wardle, R.; Roskilly, A.P.

    2017-01-01

    Future electricity systems which plan to use large proportions of intermittent (e.g. wind, solar or tidal generation) or inflexible (e.g. nuclear, coal, etc.) electricity generation sources require an increasing scale-up of energy storage to match the supply with hourly, daily and seasonal electricity demand profiles. Evaluation of how to meet this scale of energy storage has predominantly been based on the deployment of a handful of technologies including batteries, Pumped Hydroelectricity S...

  9. Design of Particle-Based Thermal Energy Storage for a Concentrating Solar Power System

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Zhiwen [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Ruichong [Colorado School of Mines; Sawaged, Fadi [Colorado School of Mines

    2017-06-03

    Solid particles can operate at higher temperature than current molten salt or oil, and they can be a heat-transfer and storage medium in a concentrating solar power (CSP) system. By using inexpensive solid particles and containment material for thermal energy storage (TES), the particle-TES cost can be significantly lower than other TES methods such as a nitrate-salt system. The particle-TES system can hold hot particles at more than 800 degrees C with high thermal performance. The high particle temperatures increase the temperature difference between the hot and cold particles, and they improve the TES capacity. The particle-based CSP system is able to support high-efficiency power generation, such as the supercritical carbon-dioxide Brayton power cycle, to achieve >50% thermal-electric conversion efficiency. This paper describes a solid particle-TES system that integrates into a CSP plant. The hot particles discharge to a heat exchanger to drive the power cycle. The returning cold particles circulate through a particle receiver to absorb solar heat and charge the TES. This paper shows the design of a particle-TES system including containment silos, foundation, silo insulation, and particle materials. The analysis provides results for four TES capacities and two silo configurations. The design analysis indicates that the system can achieve high thermal efficiency, storage effectiveness (i.e., percentage usage of the hot particles), and exergetic efficiency. An insulation method for the hot silo was considered. The particle-TES system can achieve high performance and low cost, and it holds potential for next-generation CSP technology.

  10. Grid regulation services for energy storage devices based on grid frequency

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, Richard M.; Hammerstrom, Donald J.; Kintner-Meyer, Michael C. W.; Tuffner, Francis K.

    2017-09-05

    Disclosed herein are representative embodiments of methods, apparatus, and systems for charging and discharging an energy storage device connected to an electrical power distribution system. In one exemplary embodiment, a controller monitors electrical characteristics of an electrical power distribution system and provides an output to a bi-directional charger causing the charger to charge or discharge an energy storage device (e.g., a battery in a plug-in hybrid electric vehicle (PHEV)). The controller can help stabilize the electrical power distribution system by increasing the charging rate when there is excess power in the electrical power distribution system (e.g., when the frequency of an AC power grid exceeds an average value), or by discharging power from the energy storage device to stabilize the grid when there is a shortage of power in the electrical power distribution system (e.g., when the frequency of an AC power grid is below an average value).

  11. Grid regulation services for energy storage devices based on grid frequency

    Science.gov (United States)

    Pratt, Richard M; Hammerstrom, Donald J; Kintner-Meyer, Michael C.W.; Tuffner, Francis K

    2013-07-02

    Disclosed herein are representative embodiments of methods, apparatus, and systems for charging and discharging an energy storage device connected to an electrical power distribution system. In one exemplary embodiment, a controller monitors electrical characteristics of an electrical power distribution system and provides an output to a bi-directional charger causing the charger to charge or discharge an energy storage device (e.g., a battery in a plug-in hybrid electric vehicle (PHEV)). The controller can help stabilize the electrical power distribution system by increasing the charging rate when there is excess power in the electrical power distribution system (e.g., when the frequency of an AC power grid exceeds an average value), or by discharging power from the energy storage device to stabilize the grid when there is a shortage of power in the electrical power distribution system (e.g., when the frequency of an AC power grid is below an average value).

  12. 3D graphene-based hybrid materials: synthesis and applications in energy storage and conversion.

    Science.gov (United States)

    Shi, Qiurong; Cha, Younghwan; Song, Yang; Lee, Jung-In; Zhu, Chengzhou; Li, Xiaoyu; Song, Min-Kyu; Du, Dan; Lin, Yuehe

    2016-08-25

    Porous 3D graphene-based hybrid materials (3D GBHMs) are currently attractive nanomaterials employed in the field of energy. Heteroatom-doped 3D graphene and metal, metal oxide, and polymer-decorated 3D graphene with modified electronic and atomic structures provide promising performance as electrode materials in energy storage and conversion. Numerous synthesis methods such as self-assembly, templating, electrochemical deposition, and supercritical CO2, pave the way to mass production of 3D GBHMs in the commercialization of energy devices. This review summarizes recent advances in the fabrication of 3D GBHMs with well-defined architectures such as finely controlled pore sizes, heteroatom doping types and levels. Moreover, current progress toward applications in fuel cells, supercapacitors and batteries employing 3D GBHMs is also highlighted, along with the detailed mechanisms of the enhanced electrochemical performance. Furthermore, current critical issues, challenges and future prospects with respect to applications of 3D GBHMs in practical devices are discussed at the end of this review.

  13. Battery energy storage market feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Kraft, S. [Frost and Sullivan, Mountain View, CA (United States); Akhil, A. [Sandia National Labs., Albuquerque, NM (United States). Energy Storage Systems Analysis and Development Dept.

    1997-07-01

    Under the sponsorship of the Department of Energy`s Office of Utility Technologies, the Energy Storage Systems Analysis and Development Department at Sandia National Laboratories (SNL) contracted Frost and Sullivan to conduct a market feasibility study of energy storage systems. The study was designed specifically to quantify the energy storage market for utility applications. This study was based on the SNL Opportunities Analysis performed earlier. Many of the groups surveyed, which included electricity providers, battery energy storage vendors, regulators, consultants, and technology advocates, viewed energy storage as an important enabling technology to enable increased use of renewable energy and as a means to solve power quality and asset utilization issues. There are two versions of the document available, an expanded version (approximately 200 pages, SAND97-1275/2) and a short version (approximately 25 pages, SAND97-1275/1).

  14. Toward Wearable Energy Storage Devices: Paper-Based Biofuel Cells based on a Screen-Printing Array Structure.

    Science.gov (United States)

    Shitanda, Isao; Momiyama, Misaki; Watanabe, Naoto; Tanaka, Tomohiro; Tsujimura, Seiya; Hoshi, Yoshinao; Itagaki, Masayuki

    2017-10-01

    A novel paper-based biofuel cell with a series/parallel array structure has been fabricated, in which the cell voltage and output power can easily be adjusted as required by printing. The output of the fabricated 4-series/4-parallel biofuel cell reached 0.97±0.02 mW at 1.4 V, which is the highest output power reported to date for a paper-based biofuel cell. This work contributes to the development of flexible, wearable energy storage device.

  15. Nanostructured Mn-based oxides for electrochemical energy storage and conversion.

    Science.gov (United States)

    Zhang, Kai; Han, Xiaopeng; Hu, Zhe; Zhang, Xiaolong; Tao, Zhanliang; Chen, Jun

    2015-02-07

    Batteries and supercapacitors as electrochemical energy storage and conversion devices are continuously serving for human life. The electrochemical performance of batteries and supercapacitors depends in large part on the active materials in electrodes. As an important family, Mn-based oxides have shown versatile applications in primary batteries, secondary batteries, metal-air batteries, and pseudocapacitors due to their high activity, high abundance, low price, and environmental friendliness. In order to meet future market demand, it is essential and urgent to make further improvements in energy and power densities of Mn-based electrode materials with the consideration of multiple electron reaction and low molecular weight of the active materials. Meanwhile, nanomaterials are favourable to achieve high performance by means of shortening the ionic diffusion length and providing large surface areas for electrode reactions. This article reviews the recent efforts made to apply nanostructured Mn-based oxides for batteries and pseudocapacitors. The influence of structure, morphology, and composition on electrochemical performance has been systematically summarized. Compared to bulk materials and notable metal catalysts, nanostructured Mn-based oxides can promote the thermodynamics and kinetics of the electrochemical reactions occurring at the solid-liquid or the solid-liquid-gas interface. In particular, nanostructured Mn-based oxides such as one-dimensional MnO2 nanostructures, MnO2-conductive matrix nanocomposites, concentration-gradient structured layered Li-rich Mn-based oxides, porous LiNi0.5Mn1.5O4 nanorods, core-shell structured LiMnSiO4@C nanocomposites, spinel-type Co-Mn-O nanoparticles, and perovskite-type CaMnO3 with micro-nano structures all display superior electrochemical performance. This review should shed light on the sustainable development of advanced batteries and pseudocapacitors with nanostructured Mn-based oxides.

  16. Inductive energy storage commutator

    International Nuclear Information System (INIS)

    Gavrilov, I.M.

    1987-01-01

    An inductive energy storage commutator is described. The value of commutated current is up to 800 A, the voltage amplitude in the load is up to 50 kV, the working frequency is equal to 1-50 Hz, the commutated power is up to 40 MW. The commutating device comprises of the first stage commutator having two in-series connected modules of the BTSV - 800/235 high-voltage thyristor unit, the second stage commutator containing three GMI-43A parallel connected powerful pulsed triodes, a commutating capacitor, an induction coil, two supplementary high-voltage thyristor keys (20 in-series connected thyristors T2-300 (13 class)), load, control pulse shapers, thyristor keys, power supply

  17. A Power Smoothing Control Strategy and Optimized Allocation of Battery Capacity Based on Hybrid Storage Energy Technology

    Directory of Open Access Journals (Sweden)

    Yong Li

    2012-05-01

    Full Text Available Wind power parallel operation is an effective way to realize the large scale use of wind power, but the fluctuations of power output from wind power units may have great influence on power quality, hence a new method of power smoothing and capacity optimized allocation based on hybrid energy storage technology is proposed in terms of the uncontrollable and unexpected characteristics of wind speed in wind farms. First, power smoothing based on a traditional Inertial Filter is introduced and the relationship between the time constant, its smoothing effect and capacity allocation are analyzed and combined with Proportional Integral Differential (PID control to realize power smoothing control of wind power. Then wavelet theory is adopted to realize a multi-layer decomposition of power output in some wind farms, a power smoothing model based on hybrid energy storage technology is constructed combining the characteristics of the Super Capacitor (SC and Battery Energy Storage System (BESS technologies. The hybrid energy storage system is available for power fluctuations with high frequency-low energy and low frequency-high energy to achieve good smoothing effects compared with a single energy storage system. The power fluctuations filtered by the Wavelet Transform is regarded as the target value of BESS, the charging and discharging control for battery is completed quickly by Model Algorithm Control (MAC. Because of the influence of the inertia and the response speed of the battery, its actual output is not completely equal to the target value which mainly reflects in high-frequency part, the difference part uses SC to compensate and makes the output of battery and SC closer to the target value on the whole. Compared with the traditional Inertial Filter and PID control method, the validity of the model was verified by simulation results. Finally under the premise of power grid standards, the corresponding capacity design had been given to reduce the

  18. Myo-inositol based nano-PCM for solar thermal energy storage

    International Nuclear Information System (INIS)

    Singh, D.K.; Suresh, S.; Singh, H.; Rose, B.A.J.; Tassou, S.; Anantharaman, N.

    2017-01-01

    Highlights: • Properties of Myo-Inositol laden with Al 2 O 3 and CuO nanoparticles was studied. • The melting point was found to increase for MI-A and decrease for MI-C. • MI interacted only physically on addition of NPs. • Mass changes were <3% after thermal cycling of MI-A and MI-C. • MI-A is more suited for thermal energy storage than MI-C. - Abstract: The thermo-physical behavior of Myo-Inositol (MI), (a sugar alcohol), was investigated as a potential material for developing more compact solar thermal energy storage systems than those currently available. This latent heat storage medium could be utilized for commercial and industrial applications using solar thermal energy storage in the temperature range of 160–260 °C, if its thermal performance was modified. The objective of this investigation was to determine via experimentation, if Al 2 O 3 and CuO nanoparticles dispersed in pure MI for mixtures of 1, 2 and 3% (by weight) improved the thermal performance of MI for solar thermal energy systems. Nanoparticles only physically interacted with MI, and not chemically, even after 50 thermal cycles. The distribution of CuO nanoparticles in the nano-PCM was found to be more uniform than alumina nanoparticles. After cycling, nano-MIs studied here suffered a lower decrease in heat of fusion than pure MI, which makes nano-MIs more suitable for solar thermal storage applications at 160–260 °C. Between CuO and Al 2 O 3 nanoparticles, latter was found to be more suitable for compact solar thermal energy storage owing to an increase in melting point observed.

  19. Article for thermal energy storage

    Science.gov (United States)

    Salyer, Ival O.

    2000-06-27

    A thermal energy storage composition is provided which is in the form of a gel. The composition includes a phase change material and silica particles, where the phase change material may comprise a linear alkyl hydrocarbon, water/urea, or water. The thermal energy storage composition has a high thermal conductivity, high thermal energy storage, and may be used in a variety of applications such as in thermal shipping containers and gel packs.

  20. Regenerative Carbonate-Based Thermochemical Energy Storage System for Concentrating Solar Power

    Energy Technology Data Exchange (ETDEWEB)

    Gangwal, Santosh [Southern Research Inst., Durham, NC (United States); Muto, Andrew [Southern Research Inst., Durham, NC (United States)

    2017-08-30

    Southern Research has developed a thermochemical energy storage (TCES) technology that utilizes the endothermic-exothermic reversible carbonation of calcium oxide (lime) to store thermal energy at high-temperatures, such as those achieved by next generation concentrating solar power (CSP) facilities. The major challenges addressed in the development of this system include refining a high capacity, yet durable sorbent material and designing a low thermal resistance low-cost heat exchanger reactor system to move heat between the sorbent and a heat transfer fluid under conditions relevant for CSP operation (e.g., energy density, reaction kinetics, heat flow). The proprietary stabilized sorbent was developed by Precision Combustion, Inc. (PCI). A factorial matrix of sorbent compositions covering the design space was tested using accelerated high throughput screening in a thermo-gravimetric analyzer. Several promising formulations were selected for more thorough evaluation and one formulation with high capacity (0.38 g CO2/g sorbent) and durability (>99.7% capacity retention over 100 cycles) was chosen as a basis for further development of the energy storage reactor system. In parallel with this effort, a full range of currently available commercial and developmental heat exchange reactor systems and sorbent loading methods were examined through literature research and contacts with commercial vendors. Process models were developed to examine if a heat exchange reactor system and balance of plant can meet required TCES performance and cost targets, optimizing tradeoffs between thermal performance, exergetic efficiency, and cost. Reactor types evaluated included many forms, from microchannel reactor, to diffusion bonded heat exchanger, to shell and tube heat exchangers. The most viable design for application to a supercritical CO2 power cycle operating at 200-300 bar pressure and >700°C was determined to be a combination of a diffusion bonded heat

  1. Advanced Energy Storage Systems (AESS)

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop and demonstrate advanced Energy Storage System (AESS) technologies that meet NASA's space exploration needs for safe, abundant, reliable, and lightweight...

  2. Energy Storage for Aerospace Applications

    Science.gov (United States)

    Perez-Davis, Marla E.; Loyselle, Patricia L.; Hoberecht, Mark A.; Manzo, Michelle A.; Kohout, Lisa L.; Burke, Kenneth A.; Cabrera, Carlos R.

    2001-01-01

    The NASA Glenn Research Center (GRC) has long been a major contributor to the development and application of energy storage technologies for NASAs missions and programs. NASA GRC has supported technology efforts for the advancement of batteries and fuel cells. The Electrochemistry Branch at NASA GRC continues to play a critical role in the development and application of energy storage technologies, in collaboration with other NASA centers, government agencies, industry and academia. This paper describes the work in batteries and fuel cell technologies at the NASA Glenn Research Center. It covers a number of systems required to ensure that NASAs needs for a wide variety of systems are met. Some of the topics covered are lithium-based batteries, proton exchange membrane (PEM) fuel cells, and nanotechnology activities. With the advances of the past years, we begin the 21st century with new technical challenges and opportunities as we develop enabling technologies for batteries and fuel cells for aerospace applications.

  3. Energy Storage Characteristic Analysis of Voltage Sags Compensation for UPQC Based on MMC for Medium Voltage Distribution System

    Directory of Open Access Journals (Sweden)

    Yongchun Yang

    2018-04-01

    Full Text Available The modular multilevel converter (MMC, as a new type of voltage source converter, is increasingly used because it is a distributed storage system. There are many advantages of using the topological structure of the MMC on a unified power quality controller (UPQC, and voltage sag mitigation is an important use of the MMC energy storage system for the power quality compensation process. In this paper, based on the analysis of the topology of the MMC, the essence of energy conversion in a UPQC of voltage sag compensation is analyzed; then, the energy storage characteristics are calculated and analyzed to determine the performance index of voltage sag compensation; in addition, the simulation method is used to verify the voltage sag compensation characteristics of the UPQC; finally, an industrial prototype of the UPQC based on an MMC for 10 kV of medium voltage distribution network has been developed, and the basic functions of UPQC have been tested.

  4. Battery energy storage market feasibility study

    International Nuclear Information System (INIS)

    Kraft, S.; Akhil, A.

    1997-07-01

    Under the sponsorship of the Department of Energy's Office of Utility Technologies, the Energy Storage Systems Analysis and Development Department at Sandia National Laboratories (SNL) contracted Frost and Sullivan to conduct a market feasibility study of energy storage systems. The study was designed specifically to quantify the energy storage market for utility applications. This study was based on the SNL Opportunities Analysis performed earlier. Many of the groups surveyed, which included electricity providers, battery energy storage vendors, regulators, consultants, and technology advocates, viewed energy storage as an important enabling technology to enable increased use of renewable energy and as a means to solve power quality and asset utilization issues. There are two versions of the document available, an expanded version (approximately 200 pages, SAND97-1275/2) and a short version (approximately 25 pages, SAND97-1275/1)

  5. Thermal Energy Storage Flight Experiment in Microgravity

    Science.gov (United States)

    Namkoong, David

    1992-01-01

    The Thermal Energy Storage Flight Experiment was designed to characterize void shape and location in LiF-based phase change materials in different energy storage configurations representative of advanced solar dynamic systems. Experiment goals and payload design are described in outline and graphic form.

  6. Real - time Optimization of Distributed Energy Storage System Operation Strategy Based on Peak Load Shifting

    Science.gov (United States)

    Wang, Qian; Lu, Guangqi; Li, Xiaoyu; Zhang, Yichi; Yun, Zejian; Bian, Di

    2018-01-01

    To take advantage of the energy storage system (ESS) sufficiently, the factors that the service life of the distributed energy storage system (DESS) and the load should be considered when establishing optimization model. To reduce the complexity of the load shifting of DESS in the solution procedure, the loss coefficient and the equal capacity ratio distribution principle were adopted in this paper. Firstly, the model was established considering the constraint conditions of the cycles, depth, power of the charge-discharge of the ESS, the typical daily load curves, as well. Then, dynamic programming method was used to real-time solve the model in which the difference of power Δs, the real-time revised energy storage capacity Sk and the permission error of depth of charge-discharge were introduced to optimize the solution process. The simulation results show that the optimized results was achieved when the load shifting in the load variance was not considered which means the charge-discharge of the energy storage system was not executed. In the meantime, the service life of the ESS would increase.

  7. MEMS-Based Storage Devices : Integration in Energy-Constrained Mobile Systems

    NARCIS (Netherlands)

    Khatib, M.G.

    2009-01-01

    The digital era in which we are living today requires our increasing awareness of energy efficiency to reduce the negative effects on our lovely environment. We, people, are increasingly dealing with digital contents to facilitate our deals, which increases the demand for larger storage capacities

  8. Transition-metal based oxides for oxygen storage and energy-related applications

    OpenAIRE

    Huang, Xiubing

    2015-01-01

    The development of energy storage and conversion techniques with high efficiency and power density is of great importance for the sustainable development of our green world. Li-O₂ batteries with high theoretical energy density has attracted extensive attention. However there are still many issues waiting to be solved, such as low stability of cathode catalyst, as well as the deactivation of cathode by H₂O and CO₂ from air. Reversible solid oxide fuel cells can be used for electricity producti...

  9. An Energy-Based Control Strategy for Battery Energy Storage Systems: A Case Study on Microgrid Applications

    Directory of Open Access Journals (Sweden)

    Rui Hou

    2017-02-01

    Full Text Available Battery energy storage systems (BESSs with proportional-integral (PI control methods have been widely studied in microgrids (MGs. However, the performance of PI control methods might be unsatisfactory for BESSs due to the nonlinear characteristics of the system. To overcome this problem, an energy-based (EB control method is applied to control the converter of a BESS in this study. The EB method is a robust nonlinear control method based on passivity theory with good performance in both transient and steady states. The detailed design process of the EB method in the BESS by adopting an interconnection and damping assignment (IDA strategy is described. The design process comprises three steps: the construction of the port-controlled Hamiltonian model, the determination of the equilibrium point and the solution of the undetermined matrix. In addition, integral action is combined to eliminate the steady state error generated by the model mismatch. To establish the correctness and validity of the proposed method, we implement several case simulation studies based on a test MG system and compare the control performance of the EB and PI methods carefully. The case simulation results demonstrate that the EB method has better tracking and anti-disturbance performance compared with the classic PI method. Moreover, the proposed EB method shows stronger robustness to the uncertainty of system parameters.

  10. Energy Storage and Smart Energy Systems

    Directory of Open Access Journals (Sweden)

    Poul Alberg Østergaard

    2016-12-01

    Full Text Available It is often highlighted how the transition to renewable energy supply calls for significant electricity storage. However, one has to move beyond the electricity-only focus and take a holistic energy system view to identify optimal solutions for integrating renewable energy. In this paper, an integrated cross-sector approach is used to determine the most efficient and least-cost storage options for the entire renewable energy system concluding that the best storage solutions cannot be found through analyses focusing on the individual sub-sectors. Electricity storage is not the optimum solution to integrate large inflows of fluctuating renewable energy, since more efficient and cheaper options can be found by integrating the electricity sector with other parts of the energy system and by this creating a Smart Energy System. Nevertheless, this does not imply that electricity storage should be disregarded but that it will be needed for other purposes in the future.

  11. Energy Storage and Smart Energy Systems

    DEFF Research Database (Denmark)

    Lund, Henrik; Østergaard, Poul Alberg; Connolly, David

    2016-01-01

    It is often highlighted how the transition to renewable energy supply calls for significant electricity storage. However, one has to move beyond the electricity-only focus and take a holistic energy system view to identify optimal solutions for integrating renewable energy. In this paper......, an integrated cross-sector approach is used to determine the most efficient and least-cost storage options for the entire renewable energy system concluding that the best storage solutions cannot be found through analyses focusing on the individual sub-sectors. Electricity storage is not the optimum solution...... to integrate large inflows of fluctuating renewable energy, since more efficient and cheaper options can be found by integrating the electricity sector with other parts of the energy system and by this creating a Smart Energy System. Nevertheless, this does not imply that electricity storage should...

  12. NV Energy Electricity Storage Valuation

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, James F.; Bhatnagar, Dhruv; Samaan, Nader A.; Jin, Chunlian

    2013-06-30

    This study examines how grid-level electricity storage may benet the operations of NV Energy in 2020, and assesses whether those benets justify the cost of the storage system. In order to determine how grid-level storage might impact NV Energy, an hourly production cost model of the Nevada Balancing Authority (\\BA") as projected for 2020 was built and used for the study. Storage facilities were found to add value primarily by providing reserve. Value provided by the provision of time-of-day shifting was found to be limited. If regulating reserve from storage is valued the same as that from slower ramp rate resources, then it appears that a reciprocating engine generator could provide additional capacity at a lower cost than a pumped storage hydro plant or large storage capacity battery system. In addition, a 25-MW battery storage facility would need to cost $650/kW or less in order to produce a positive Net Present Value (NPV). However, if regulating reserve provided by storage is considered to be more useful to the grid than that from slower ramp rate resources, then a grid-level storage facility may have a positive NPV even at today's storage system capital costs. The value of having storage provide services beyond reserve and time-of-day shifting was not assessed in this study, and was therefore not included in storage cost-benefit calculations.

  13. A Vertical Flux-Switching Permanent Magnet Based Oscillating Wave Power Generator with Energy Storage

    Directory of Open Access Journals (Sweden)

    Yu Zou

    2017-06-01

    Full Text Available In this paper, an effective low-speed oscillating wave power generator and its energy storage system have been proposed. A vertical flux-switching permanent magnet (PM machine is designed as the generator while supercapacitors and batteries are used to store the energy. First, the overall power generation system is established and principles of the machine are introduced. Second, three modes are proposed for the energy storage system and sliding mode control (SMC is employed to regulate the voltage of the direct current (DC bus, observe the mechanical input, and feedback the status of the storage system. Finally, experiments with load and sinusoidal mechanical inputs are carried out to validate the effectiveness and stability of power generation for wave energy. The results show that the proposed power generation system can be employed in low-speed environment around 1 m/s to absorb random wave power, achieving over 60% power efficiency. The power generation approach can be used to capture wave energy in the future.

  14. Review of thermal energy storage technologies based on PCM application in buildings

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Zhang, Yinping

    2013-01-01

    Thermal energy storage systems (TES), using phase change material (PCM) in buildings, are widely investigated technologies and a fast developing research area. Therefore, there is a need for regular and consistent reviews of the published studies. This review is focused on PCM technologies...... developed to serve the building industry. Various PCM technologies tailored for building applications are studied with respect to technological potential to improve indoor environment, increase thermal inertia and decrease energy use for building operation. What is more, in this review special attention...... is paid to discussion and identification of proper methods to correctly determine the thermal properties of PCM materials and their composites and as well procedures to determine their energy storage and saving potential. The purpose of the paper is to highlight promising technologies for PCM application...

  15. Electrochemical energy storage device based on carbon dioxide as electroactive species

    Science.gov (United States)

    Nemeth, Karoly; van Veenendaal, Michel Antonius; Srajer, George

    2013-03-05

    An electrochemical energy storage device comprising a primary positive electrode, a negative electrode, and one or more ionic conductors. The ionic conductors ionically connect the primary positive electrode with the negative electrode. The primary positive electrode comprises carbon dioxide (CO.sub.2) and a means for electrochemically reducing the CO.sub.2. This means for electrochemically reducing the CO.sub.2 comprises a conductive primary current collector, contacting the CO.sub.2, whereby the CO.sub.2 is reduced upon the primary current collector during discharge. The primary current collector comprises a material to which CO.sub.2 and the ionic conductors are essentially non-corrosive. The electrochemical energy storage device uses CO.sub.2 as an electroactive species in that the CO.sub.2 is electrochemically reduced during discharge to enable the release of electrical energy from the device.

  16. Thermal energy storage characteristics of bentonite-based composite PCMs with enhanced thermal conductivity as novel thermal storage building materials

    International Nuclear Information System (INIS)

    Sarı, Ahmet

    2016-01-01

    Graphical abstract: In this work, novel bentonite-based and form-stable composite phase change materials (Bb-FSPCMs) were produced for LHTES in buildings by impregnation of CA, PEG600, DD and HD with bentonite clay. The microstructures of the compatibility of the Bb-FSPCMs were by using SEM and FT-IR techniques. The DSC results indicated that the produced Bb-FSPCMs composites had suitable phase change temperature of 4–30 °C and good latent heat capacity between 38 and 74 J/g. The TG results demonstrated that all of the fabricated Bb-FSPCMs had good thermal resistance. The Bb-FSPCMs maintained their LHTES properties even after 1000 heating–cooling cycling. The total heating times of the prepared Bb-FSPCMs were reduced noticeably due to their enhanced thermal conductivity after EG (5 wt%) addition. - Highlights: • Bb-FSPCMs were produced by impregnation of CA, PEG600, DD and HD with bentonite. • DSC analysis indicated that Bb-FSPCMs had melting temperature in range of 4–30 °C. • DSC analysis also showed that Bb-FSPCMs had latent heat between 38 and 74 J/g. • The TG analysis demonstrated that Bb-FSPCMs had good thermal resistance. • Thermal conductivity of Bb-FSPCMs were enhanced noticeably with EG (5 wt%) addition. - Abstract: In this work, for latent heat thermal energy storage (LHTES) applications in buildings, bentonite-based form-stable composite phase change materials (Bb-FSPCMs) were produced by impregnation of capric acid (CA), polyethylene glycol (PEG600), dodecanol (DD) and heptadecane (HD) into bentonite clay. The morphological characterization results obtained by scanning electron microscopy (SEM) showed that the bentonite acted as good structural barrier for the organic PCMs homogenously dispersed onto its surface and interlayers. The chemical investigations made by using fourier transform infrared (FT-IR) technique revealed that the attractions between the components of the composites was physical in nature and thus the PCMs were hold

  17. Design of arc power supply for neutral beam injection system based on super capacitor energy storage

    International Nuclear Information System (INIS)

    Yang Puqiong; Xuan Weimin; Cao Jianyong; Li Qing; Liu Xiaolong

    2015-01-01

    The arc power supply is one of the most important equipment for neutral beam injection system. The stability of arc discharge and the quality of ion beam extraction were determined by its performance. For improving stability of the arc discharge, reducing the power network capacity and decreasing impulse on power network, the topology of the arc power supply applied the structure of DC/DC converter based on technology of super capacitor energy storage and switching power supply. Several IGBT power modules are operated in parallel, and it can improve the arc power supply's operating frequency and dynamic response. A filter circuit and a current fast transferring circuit were designed based on a detailed analysis on working process of the arc power sup- ply. According to the requirements and parameters of the arc power supply, and the current response of RL first order circuit, the minimum filter inductances were accurately calculated. Finally, using the model and Matlab, the performance of the arc power supply was simulated and verified, and it meets the design requirement. (authors)

  18. Double-Quadrant State-of-Charge-Based Droop Control Method for Distributed Energy Storage Systems in Autonomous DC Microgrids

    DEFF Research Database (Denmark)

    Lu, Xiaonan; Sun, Kai; Guerrero, Josep M.

    2015-01-01

    In this paper, a double-quadrant state-of-charge (SoC) based droop control method for distributed energy storage system (DESS) is proposed to reach the proper power distribution in autonomous DC microgrids. Since DESS is commonly used in DC microgrids, it is necessary to achieve the rational power...... sharing in both charging and discharging process. In order to prolong the lifetime of the energy storage units (ESUs) and avoid the overuse of a certain unit, the SoC of each unit should be balanced and the injected/output power should be gradually equalized. Droop control as a decentralized approach...... is used as the basis of the power sharing method for distributed energy storage units (DESUs). In the charging process, the droop coefficient is set to be proportional to the nth order of SoC, while in the discharging process, the droop coefficient is set to be inversely proportional to the nth order...

  19. Review of Phase Change Materials Based on Energy Storage System with Applications

    Science.gov (United States)

    Thamaraikannn, R.; Kanimozhi, B.; Anish, M.; Jayaprabakar, J.; Saravanan, P.; Rohan Nicholas, A.

    2017-05-01

    The use of Different types of storage system using phase change materials (PCMs) is an effective way of storing energy and also to make advantages of heating and cooling systems are installed to maintain temperatures within the well-being zone. PCMs have been extensively used in various storage systems for heat pumps, solar engineering, and thermal control applications. The use of PCM’s for heating and cooling applications have been investigated during the past decade. There are large numbers of PCM’s, which melt and solidify at a wide range of temperatures, making them attractive in a number of applications. This paper also outline the investigation and analysis of Phase Change materials used in Different Types of storage systems with different applications.

  20. Nanocarbons for advanced energy storage

    CERN Document Server

    Feng, Xinliang

    2015-01-01

    This first volume in the series on nanocarbons for advanced applications presents the latest achievements in the design, synthesis, characterization, and applications of these materials for electrochemical energy storage. The highly renowned series and volume editor, Xinliang Feng, has put together an internationally acclaimed expert team who covers nanocarbons such as carbon nanotubes, fullerenes, graphenes, and porous carbons. The first two parts focus on nanocarbon-based anode and cathode materials for lithium ion batteries, while the third part deals with carbon material-based supercapacit

  1. Coordinated Control for Flywheel Energy Storage Matrix Systems for Wind Farm Based on Charging/Discharging Ratio Consensus Algorithms

    DEFF Research Database (Denmark)

    Cao, Qian; Song, Y. D.; Guerrero, Josep M.

    2016-01-01

    This paper proposes a distributed algorithm for coordination of flywheel energy storage matrix system (FESMS) cooperated with wind farm. A simple and distributed ratio consensus algorithm is proposed to solve FESMS dispatch problem. The algorithm is based on average consensus for both undirected...

  2. Multiagent-Based Distributed State of Charge Balancing Control for Distributed Energy Storage Units in AC Microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Coelho, Ernane Antônio Alves; Dragicevic, Tomislav

    2017-01-01

    In this paper, a multiagent-based distributed control algorithm has been proposed to achieve state of charge (SoC) balance of distributed energy storage (DES) units in an ac microgrid. The proposal uses frequency scheduling instead of adaptive droop gain to regulate the active power. Each DES unit...

  3. Smoothing of wind farm output power using prediction based flywheel energy storage system

    Science.gov (United States)

    Islam, Farzana

    Being socially beneficial, economically competitive and environment friendly, wind energy is now considered to be the world's fastest growing renewable energy source. However, the stochastic nature of wind imposes a considerable challenge in the optimal management and operation of wind power system. Wind speed prediction is critical for wind energy conversion system since it greatly influences the issues related to effective energy management, dynamic control of wind turbine, and improvement of the overall efficiency of the power generation system. This thesis focuses on integration of energy storage system with wind farm, considering wind speed prediction in the control scheme to overcome the problems associated with wind power fluctuations. In this thesis, flywheel energy storage system (FESS) with adjustable speed rotary machine has been considered for smoothing of output power in a wind farm composed of a fixed speed wind turbine generator (FSWTG). Since FESS has both active and reactive power compensation ability, it enhances the stability of the system effectively. An efficient energy management system combined with supervisory control unit (SCU) for FESS and wind speed prediction has been developed to improve the smoothing of the wind farm output effectively. Wind speed prediction model is developed by artificial neural network (ANN) which has advantages over the conventional prediction scheme including data error tolerance and ease in adaptability. The model for prediction with ANN is developed in MATLAB/Simulink and interfaced with PSCAD/EMTDC. Effectiveness of the proposed control system is illustrated using real wind speed data in various operating conditions.

  4. The role of nanomaterials in redox-based supercapacitors for next generation energy storage devices.

    Science.gov (United States)

    Zhao, Xin; Sánchez, Beatriz Mendoza; Dobson, Peter J; Grant, Patrick S

    2011-03-01

    The development of more efficient electrical storage is a pressing requirement to meet future societal and environmental needs. This demand for more sustainable, efficient energy storage has provoked a renewed scientific and commercial interest in advanced capacitor designs in which the suite of experimental techniques and ideas that comprise nanotechnology are playing a critical role. Capacitors can be charged and discharged quickly and are one of the primary building blocks of many types of electrical circuit, from microprocessors to large-sale power supplies, but usually have relatively low energy storage capability when compared with batteries. The application of nanostructured materials with bespoke morphologies and properties to electrochemical supercapacitors is being intensively studied in order to provide enhanced energy density without comprising their inherent high power density and excellent cyclability. In particular, electrode materials that exploit physical adsorption or redox reactions of electrolyte ions are foreseen to bridge the performance disparity between batteries with high energy density and capacitors with high power density. In this review, we present some of the novel nanomaterial systems applied for electrochemical supercapacitors and show how material morphology, chemistry and physical properties are being tailored to provide enhanced electrochemical supercapacitor performance.

  5. Contemporary energy storage sources. Energy saving

    International Nuclear Information System (INIS)

    Manev, Veselin

    2011-01-01

    The development of renewable energy system for electricity production is impede because of needs to be stabilized with nearly equivalent installed power of energy storage devices. The development of more electrical energy storage facilities will be extremely important for electricity generation in the future. Using hydro pumping, combined with a long life and fast charge/discharge rate, highly efficient contemporary power energy storage as Altairnano lithium ion battery, currently is seems to be the best solution for fast penetration rate of wind and solar energy systems

  6. Electrochemical Impedance Analysis of a PEDOT:PSS-Based Textile Energy Storage Device

    Science.gov (United States)

    Gokceoren, Argun Talat; Odhiambo, Sheilla Atieno; De Mey, Gilbert; Hertleer, Carla; Van Langenhove, Lieva

    2017-01-01

    A textile-based energy storage device with electroactive PEDOT:PSS (poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate)) polymer functioning as a solid-state polyelectrolyte has been developed. The device was fabricated on textile fabric with two plies of stainless-steel electroconductive yarn as the electrodes. In this study, cyclic voltammetry and electrochemical impedance analysis were used to investigate ionic and electronic activities in the bulk of PEDOT:PSS and at its interfaces with stainless steel yarn electrodes. The complex behavior of ionic and electronic origins was observed in the interfacial region between the conductive polymer and the electrodes. The migration and diffusion of the ions involved were confirmed by the presence of the Warburg element with a phase shift of 45° (n = 0.5). Two different equivalent circuit models were found by simulating the model with the experimental results: (QR)(QR)(QR) for uncharged and (QR)(QR)(Q(RW)) for charged samples. The analyses also showed that the further the distance between electrodes, the lower the capacitance of the cell. The distribution of polymer on the cell surface also played important role to change the capacitance of the device. The results of this work may lead to a better understanding of the mechanism and how to improve the performance of the device. PMID:29283427

  7. Deployment strategy for battery energy storage system in distribution network based on voltage violation regulation

    Science.gov (United States)

    Wu, H.; Zhou, L.; Xu, T.; Fang, W. L.; He, W. G.; Liu, H. M.

    2017-11-01

    In order to improve the situation of voltage violation caused by the grid-connection of photovoltaic (PV) system in a distribution network, a bi-level programming model is proposed for battery energy storage system (BESS) deployment. The objective function of inner level programming is to minimize voltage violation, with the power of PV and BESS as the variables. The objective function of outer level programming is to minimize the comprehensive function originated from inner layer programming and all the BESS operating parameters, with the capacity and rated power of BESS as the variables. The differential evolution (DE) algorithm is applied to solve the model. Based on distribution network operation scenarios with photovoltaic generation under multiple alternative output modes, the simulation results of IEEE 33-bus system prove that the deployment strategy of BESS proposed in this paper is well adapted to voltage violation regulation invariable distribution network operation scenarios. It contributes to regulating voltage violation in distribution network, as well as to improve the utilization of PV systems.

  8. Electrochemical Impedance Analysis of a PEDOT:PSS-Based Textile Energy Storage Device

    Directory of Open Access Journals (Sweden)

    Ida Nuramdhani

    2017-12-01

    Full Text Available A textile-based energy storage device with electroactive PEDOT:PSS (poly(3,4-ethylenedioxythiophene/poly(4-styrenesulfonate polymer functioning as a solid-state polyelectrolyte has been developed. The device was fabricated on textile fabric with two plies of stainless-steel electroconductive yarn as the electrodes. In this study, cyclic voltammetry and electrochemical impedance analysis were used to investigate ionic and electronic activities in the bulk of PEDOT:PSS and at its interfaces with stainless steel yarn electrodes. The complex behavior of ionic and electronic origins was observed in the interfacial region between the conductive polymer and the electrodes. The migration and diffusion of the ions involved were confirmed by the presence of the Warburg element with a phase shift of 45° (n = 0.5. Two different equivalent circuit models were found by simulating the model with the experimental results: (QR(QR(QR for uncharged and (QR(QR(Q(RW for charged samples. The analyses also showed that the further the distance between electrodes, the lower the capacitance of the cell. The distribution of polymer on the cell surface also played important role to change the capacitance of the device. The results of this work may lead to a better understanding of the mechanism and how to improve the performance of the device.

  9. Smart nanopaper based on cellulose nanofibers with hybrid PEDOT:PSS/polypyrrole for energy storage devices.

    Science.gov (United States)

    Lay, Makara; Pèlach, M Àngels; Pellicer, Neus; Tarrés, Joaquim A; Bun, Kim Ngun; Vilaseca, Fabiola

    2017-06-01

    In the current work, flexible, lightweight, and strong conductive nanopapers based on cellulose nanofibers (CNFs) with poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and/or polypyrrole (PPy) were prepared by following a mixing and in situ chemical polymerization method. A successful homogeneous coating of PEDOT:PSS on cellulose nanofibers occurred by means hydrogen-bonding interactions between the hydroxyl functionalized CNF and the electronically charged PEDOT:PSS, as shown by FTIR spectra. The electrical conductivity and the specific capacitance of CNF-PEDOT:PSS nanopapers were 2.58Scm -1 and 6.21Fg -1 , respectively. Further coating of PPy produced a substantial improvement on the electrical conductivity (10.55Scm -1 ) and the specific capacitance (315.5Fg -1 ) of the resulting CNF-PEDOT:PSS-PPy nanopaper. A synergistic phenomenon between both conductive polymers supported the high electrical conductivity and specific capacitance of the ternary formulation. Moreover, CNF-PEDOT:PSS-PPy nanopaper showed higher mechanical properties and it was more flexible than the nanopaper containing only polypyrrole conducting polymer (CNF-PPy). It is concluded that the good mechanical, electrical and electrochemical properties of the ternary formulation can apply for smart nanopaper in flexible electronics and energy storage devices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Neural Network based Control of SG based Standalone Generating System with Energy Storage for Power Quality Enhancement

    Science.gov (United States)

    Nayar, Priya; Singh, Bhim; Mishra, Sukumar

    2017-08-01

    An artificial intelligence based control algorithm is used in solving power quality problems of a diesel engine driven synchronous generator with automatic voltage regulator and governor based standalone system. A voltage source converter integrated with a battery energy storage system is employed to mitigate the power quality problems. An adaptive neural network based signed regressor control algorithm is used for the estimation of the fundamental component of load currents for control of a standalone system with load leveling as an integral feature. The developed model of the system performs accurately under varying load conditions and provides good dynamic response to the step changes in loads. The real time performance is achieved using MATLAB along with simulink/simpower system toolboxes and results adhere to an IEEE-519 standard for power quality enhancement.

  11. An Empirical Model for Energy Storage Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rosewater, David Martin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Scott, Paul [TransPower, Poway, CA (United States)

    2016-03-17

    Improved models of energy storage systems are needed to enable the electric grid’s adaptation to increasing penetration of renewables. This paper develops a generic empirical model of energy storage system performance agnostic of type, chemistry, design or scale. Parameters for this model are calculated using test procedures adapted from the US DOE Protocol for Uniformly Measuring and Expressing the Performance of Energy Storage. We then assess the accuracy of this model for predicting the performance of the TransPower GridSaver – a 1 MW rated lithium-ion battery system that underwent laboratory experimentation and analysis. The developed model predicts a range of energy storage system performance based on the uncertainty of estimated model parameters. Finally, this model can be used to better understand the integration and coordination of energy storage on the electric grid.

  12. Thermal transfer performance of a spherical encapsulated PEG 6000-based composite for thermal energy storage

    Czech Academy of Sciences Publication Activity Database

    Anghel, E.M.; Pavel, P.M.; Constantinescu, M.; Petrescu, S.; Atkinson, I.; Buixaderas, Elena

    2017-01-01

    Roč. 208, Sep (2017), s. 1222-1231 ISSN 0306-2619 Grant - others:AV ČR(CZ) AR-17-02 Program:Bilaterální spolupráce Institutional support: RVO:68378271 Keywords : phase change materials * thermal energy storage * modeling Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 7.182, year: 2016

  13. Energy storage. A challenge for energy transition

    International Nuclear Information System (INIS)

    Bart, Jean-Baptiste; Nekrasov, Andre; Pastor, Emmanuel; Benefice, Emmanuel; Brincourt, Thierry; Brisse, Annabelle; Cagnac, Albannie; Delille, Gauthier; Hinchliffe, Timothee; Lancel, Gilles; Jeandel, Elodie; Lefebvre, Thierry; Loevenbruck, Philippe; Penneau, Jean-Francois; Soler, Robert; Stevens, Philippe; Radvanyi, Etienne; Torcheux, Laurent

    2017-06-01

    Written by several EDF R and D engineers, this book aims at presenting an overview of knowledge and know-how of EDF R and D in the field of energy storage, and at presenting the different technologies and their application to electric power systems. After a description of the context related to a necessary energy transition, the authors present the numerous storage technologies. They distinguish direct storage of power (pumped storage water stations, compressed air energy storage, flywheels, the various electrochemical batteries, metal-air batteries, redox flow batteries, superconductors), thermal storage (power to heat, heat to power) and hydrogen storage (storage under different forms), and propose an overview of the situation of standardisation of storage technologies. In the next part, they give an overview of the main services provided by storage to the electric power system: production optimisation, frequency adjustment, grid constraint resolution, local smoothing of PV and wind production, supply continuity. The last part discusses perspectives regarding the role of tomorrow's storage in the field of electrical mobility, for emerging markets, and with respect to different scenarios

  14. Biodigester as an energy storage system

    Energy Technology Data Exchange (ETDEWEB)

    Borges Neto, M.R.; Lopes, L.C.N. [Federal Institute of Education, Science and Technology of Sertao Pernambucano (IFSertao-PE), Petrolina, PE (Brazil)], Emails: rangel@cefetpet.br; Pinheiro Neto, J.S.; Carvalho, P.C.M. [Federal University of Ceara (UFC), Fortaleza, CE (Brazil). Dept. of Electrical Engineering], Emails: neto@tbmtextil.com.br, carvalho@dee.ufc.br; Silveira, G.C.; Moreira, A.P.; Borges, T.S.H. [Federal Institute of Education, Science and Technology of Ceara (IFCE), Fortaleza, CE (Brazil)], Emails: gcsilveira@cefet-ce.br, apmoreira@ifce.edu.br, thatyanys@yahoo.com.br

    2009-07-01

    Electricity supply for rural and remote areas is becoming an increasing priority to developing countries. The high initial cost of renewable energy based unities usually needs an energy storage system; due its operational and even replacement cost contributes to a higher final cost. The choice of energy storage systems depends on the sort and size of adopted power supply. This paper has a main goal to introduce a renewable energy based storage system weakly explored in Brazil: biogas from anaerobic digestion. It also brings a review of the main energy storage systems applied to electrical energy generation. As reference an experiment with an adapted Indian digester of 5 m{sup 3} that produced nearly 2m{sup 3} of biogas daily. The obtained biogas met the consumption of at least 4 typical Brazilian low income households with installed load of 500 W each and was enough to replace the use of 420 Ah lead-acid batteries. (author)

  15. Development of Si-based detectors for intermediate energy heavy-ion physics at a storage-ring accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Whitlow, H.J.; Jaworowski, J.; Leandersson, M.; El Bouanani, M. [Lund Institute of Technology, Solvegatan Lund, (Sweden). Department of Nuclear Physics; Jakobsson, B. [Lund Univ. (Sweden). Dept. of Cosmic and Subatomic Physics; Romanski, J.; Westerberg, L.; Van Veldhuizen, E.J. [Uppsala Univ. (Sweden); The Chicsi Collaboration

    1996-12-31

    Ultrahigh vacuum (UHV) compatible Si detectors are being developed by the CELSIUS Heavy lon Collaboration (CHIC) for measuring the energy and identity of Intermediate Mass Fragments (IMF) with Z {approx} 3 - 12 and energies of 0.7 - I 0 A MeV. Here we give an overview of the development of Si {delta}E-E detector telescopes and investigations on IMF identification based on the pulse shape from Si-detectors where the particles impinge on the rear-face of the detector. 9 refs., 4 figs.

  16. Thermodynamic analysis of a combined-cycle solar thermal power plant with manganese oxide-based thermochemical energy storage

    Science.gov (United States)

    Lei, Qi; Bader, Roman; Kreider, Peter; Lovegrove, Keith; Lipiński, Wojciech

    2017-11-01

    We explore the thermodynamic efficiency of a solar-driven combined cycle power system with manganese oxide-based thermochemical energy storage system. Manganese oxide particles are reduced during the day in an oxygen-lean atmosphere obtained with a fluidized-bed reactor at temperatures in the range of 750-1600°C using concentrated solar energy. Reduced hot particles are stored and re-oxidized during night-time to achieve continuous power plant operation. The steady-state mass and energy conservation equations are solved for all system components to calculate the thermodynamic properties and mass flow rates at all state points in the system, taking into account component irreversibilities. The net power block and overall solar-to-electric energy conversion efficiencies, and the required storage volumes for solids and gases in the storage system are predicted. Preliminary results for a system with 100 MW nominal solar power input at a solar concentration ratio of 3000, designed for constant round-the-clock operation with 8 hours of on-sun and 16 hours of off-sun operation and with manganese oxide particles cycled between 750 and 1600°C yield a net power block efficiency of 60.0% and an overall energy conversion efficiency of 41.3%. Required storage tank sizes for the solids are estimated to be approx. 5-6 times smaller than those of state-of-the-art molten salt systems.

  17. Novel Integration of Perovskite Solar Cell and Supercapacitor Based on Carbon Electrode for Hybridizing Energy Conversion and Storage.

    Science.gov (United States)

    Liu, Zhiyong; Zhong, Yan; Sun, Bo; Liu, Xingyue; Han, Jinghui; Shi, Tielin; Tang, Zirong; Liao, Guanglan

    2017-07-12

    Power packs integrating both photovoltaic parts and energy storage parts have gained great scientific and technological attention due to the increasing demand for green energy and the tendency for miniaturization and multifunctionalization in electronics industry. In this study, we demonstrate novel integration of perovskite solar cell and solid-state supercapacitor for power packs. The perovskite solar cell is integrated with the supercapacitor based on common carbon electrodes to hybridize photoelectric conversion and energy storage. The power pack achieves a voltage of 0.84 V when the supercapacitor is charged by the perovskite solar cell under the AM 1.5G white light illumination with a 0.071 cm 2 active area, reaching an energy storage proportion of 76% and an overall conversion efficiency of 5.26%. When the supercapacitor is precharged at 1.0 V, an instant overall output efficiency of 22.9% can be achieved if the perovskite solar cell and supercapacitor are connected in series, exhibiting great potential in the applications of solar energy storage and flexible electronics such as portable and wearable devices.

  18. Thermodynamic analysis of a combined-cycle solar thermal power plant with manganese oxide-based thermochemical energy storage

    Directory of Open Access Journals (Sweden)

    Lei Qi

    2017-01-01

    Full Text Available We explore the thermodynamic efficiency of a solar-driven combined cycle power system with manganese oxide-based thermochemical energy storage system. Manganese oxide particles are reduced during the day in an oxygen-lean atmosphere obtained with a fluidized-bed reactor at temperatures in the range of 750–1600°C using concentrated solar energy. Reduced hot particles are stored and re-oxidized during night-time to achieve continuous power plant operation. The steady-state mass and energy conservation equations are solved for all system components to calculate the thermodynamic properties and mass flow rates at all state points in the system, taking into account component irreversibilities. The net power block and overall solar-to-electric energy conversion efficiencies, and the required storage volumes for solids and gases in the storage system are predicted. Preliminary results for a system with 100 MW nominal solar power input at a solar concentration ratio of 3000, designed for constant round-the-clock operation with 8 hours of on-sun and 16 hours of off-sun operation and with manganese oxide particles cycled between 750 and 1600°C yield a net power block efficiency of 60.0% and an overall energy conversion efficiency of 41.3%. Required storage tank sizes for the solids are estimated to be approx. 5–6 times smaller than those of state-of-the-art molten salt systems.

  19. Energy management strategy based on short-term generation scheduling for a renewable microgrid using a hydrogen storage system

    DEFF Research Database (Denmark)

    Cau, Giorgo; Cocco, Daniele; Petrollese, Mario

    2014-01-01

    This paper presents a novel energy management strategy (EMS) to control an isolated microgrid powered by a photovoltaic array and a wind turbine and equipped with two different energy storage systems: electric batteries and a hydrogen production and storage system. In particular, an optimal...... scheduling of storage devices is carried out to maximize the benefits of available renewable resources by operating the photovoltaic systems and the wind turbine at their maximum power points and by minimizing the overall utilization costs. Unlike conventional EMS based on the state-of-charge (SOC......) of batteries, the proposed EMS takes into account the uncertainty due to the intermittent nature of renewable resources and electricity demand. In particular, the uncertainties are evaluated with a stochastic approach through the construction of different scenarios with corresponding probabilities. The EMS...

  20. Scattering-layer-induced energy storage function in polymer-based quasi-solid-state dye-sensitized solar cells.

    Science.gov (United States)

    Zhang, Xi; Jiang, Hongrui

    2015-03-09

    Photo-self-charging cells (PSCs) are compact devices with dual functions of photoelectric conversion and energy storage. By introducing a scattering layer in polymer-based quasi-solid-state dye-sensitized solar cells, two-electrode PSCs with highly compact structure were obtained. The charge storage function stems from the formed ion channel network in the scattering layer/polymer electrolyte system. Both the photoelectric conversion and the energy storage functions are integrated in only the photoelectrode of such PSCs. This design of PSC could continuously output power as a solar cell with considerable efficiency after being photo-charged. Such PSCs could be applied in highly-compact mini power devices.

  1. Heat Modeling and Material Development of Mg-Based Nanomaterials Combined with Solid Oxide Fuel Cell for Stationary Energy Storage

    Directory of Open Access Journals (Sweden)

    Huaiyu Shao

    2017-11-01

    Full Text Available Mg-based materials have been investigated as hydrogen storage materials, especially for possible onboard storage in fuel cell vehicles for decades. Recently, with the development of large-scale fuel cell technologies, the development of Mg-based materials as stationary storage to supply hydrogen to fuel-cell components and provide electricity and heat is becoming increasingly promising. In this work, numerical analysis of heat balance management for stationary solid oxide fuel cell (SOFC systems combined with MgH2 materials based on a carbon-neutral design concept was performed. Waste heat from the SOFC is supplied to hydrogen desorption as endothermic heat for the MgH2 materials. The net efficiency of this model achieves 82% lower heating value (LHV, and the efficiency of electrical power output becomes 68.6% in minimizing heat output per total energy output when all available heat of waste gas and system is supplied to warm up the storage. For the development of Mg-based hydrogen storage materials, various nano-processing techniques have been widely applied to synthesize Mg-based materials with small particle and crystallite sizes, resulting in good hydrogen storage kinetics, but poor thermal conductivity. Here, three kinds of Mg-based materials were investigated and compared: 325 mesh Mg powers, 300 nm Mg nanoparticles synthesized by hydrogen plasma metal reaction, and Mg50Co50 metastable alloy with body-centered cubic structure. Based on the overall performances of hydrogen capacity, absorption kinetics and thermal conductivity of the materials, the Mg nanoparticle sample by plasma synthesis is the most promising material for this potential application. The findings in this paper may shed light on a new energy conversion and utilization technology on MgH2-SOFC combined concept.

  2. Promising future energy storage systems: Nanomaterial based systems, Zn-air, and electromechanical batteries

    Science.gov (United States)

    Koopman, R.; Richardson, J.

    1993-10-01

    Future energy storage systems will require longer shelf life, higher duty cycles, higher efficiency, higher energy and power densities, and be fabricated in an environmentally conscious process. This paper describes several possible future systems which have the potential of providing stored energy for future electric and hybrid vehicles. Three of the systems have their origin in the control of material structure at the molecular level and the subsequent nanoengineering into useful device and components: aerocapacitors, nanostructure multilayer capacitors, and the lithium ion battery. The zinc-air battery is a high energy density battery which can provide vehicles with long range (400 km in autos) and be rapidly refueled with a slurry of zinc particles and electrolyte. The electromechanical battery is a battery-sized module containing a high-speed rotor integrated with an iron-less generator mounted on magnetic bearings and housed in an evacuated chamber.

  3. Intercalation Pseudocapacitance in Ultrathin VOPO4 Nanosheets: Toward High-Rate Alkali-Ion-Based Electrochemical Energy Storage.

    Science.gov (United States)

    Zhu, Yue; Peng, Lele; Chen, Dahong; Yu, Guihua

    2016-01-13

    There is a growing need for energy storage devices in numerous applications where a large amount of energy needs to be either stored or delivered quickly. The present paper details the study of alkali-ion intercalation pseudocapacitance in ultrathin VOPO4 nanosheets, which hold promise in high-rate alkali-ion based electrochemical energy storage. Starting from bulk VOPO4·2H2O chunks, VOPO4 nanosheets were obtained through simple ultrasonication in 2-propanol. These nanosheets as the cathode exhibit a specific capacity of 154 and 136 mAh/g (close to theoretical value 166 mAh/g) for lithium and sodium storage devices at 0.1 C and 100 and ∼70 mAh/g at 5 C, demonstrating their high rate capability. Moreover, the capacity retention is maintained at 90% for lithium ion storage and 73% for sodium ion storage after 500 cycles, showing their reasonable stability. The demonstrated alkali-ion intercalation pseudocapacitance represents a promising direction for developing battery materials with promising high rate capability.

  4. A low-cost hybrid drivetrain concept based on compressed air energy storage

    International Nuclear Information System (INIS)

    Brown, T.L.; Atluri, V.P.; Schmiedeler, J.P.

    2014-01-01

    Highlights: • A new pneumatic hybrid concept is introduced. • A proof-of-concept prototype system is built and tested. • The experimental system has a round-trip efficiency of just under 10%. • A thermodynamics model is used to predict the performance of modified designs. • An efficiency of nearly 50% is possible with reasonable design changes. - Abstract: This paper introduces a new low-cost hybrid drivetrain concept based on compressed air energy storage. In contrast to most contemporary approaches to pneumatic hybridization, which require modification to the primary power plant, this concept is based on a stand-alone pneumatic system that could be readily integrated with existing vehicles. The pneumatic system consists of an air tank and a compressor–expander that is coupled to the rest of the drivetrain via an infinitely variable transmission. Rather than incorporating more expensive technologies such as variable valve timing or a variable compression ratio compressor, a fixed valve system consisting of a rotary valve and passive check valves is optimized to operate efficiently over a range of tank pressures. The feasibility of this approach is established by thermodynamic modeling and the construction of a proof-of-concept prototype, which is also used to fine tune model parameters. While the proof-of-concept system shows a round trip efficiency of just under 10%, modeling shows that a round trip efficiency of 26% is possible with a revised design. If waste heat from the engine is used to maintain an elevated tank temperature, efficiencies of nearly 50% may be possible, indicating that the concept could be effective for practical hybridization of passenger vehicles

  5. Optimal Energy Management, Location and Size for Stationary Energy Storage System in a Metro Line Based on Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Huan Xia

    2015-10-01

    Full Text Available The installation of stationary super-capacitor energy storage system (ESS in metro systems can recycle the vehicle braking energy and improve the pantograph voltage profile. This paper aims to optimize the energy management, location, and size of stationary super-capacitor ESSes simultaneously and obtain the best economic efficiency and voltage profile of metro systems. Firstly, the simulation platform of an urban rail power supply system, which includes trains and super-capacitor energy storage systems, is established. Then, two evaluation functions from the perspectives of economic efficiency and voltage drop compensation are put forward. Ultimately, a novel optimization method that combines genetic algorithms and a simulation platform of urban rail power supply system is proposed, which can obtain the best energy management strategy, location, and size for ESSes simultaneously. With actual parameters of a Chinese metro line applied in the simulation comparison, certain optimal scheme of ESSes’ energy management strategy, location, and size obtained by a novel optimization method can achieve much better performance of metro systems from the perspectives of two evaluation functions. The simulation result shows that with the increase of weight coefficient, the optimal energy management strategy, locations and size of ESSes appear certain regularities, and the best compromise between economic efficiency and voltage drop compensation can be obtained by a novel optimization method, which can provide a valuable reference to subway company.

  6. Seasonal Thermal Energy Storage Program

    Science.gov (United States)

    Minor, J. E.

    1980-01-01

    The Seasonal Thermal Energy Storage (STES) Program designed to demonstrate the storage and retrieval of energy on a seasonal basis using heat or cold available from waste or other sources during a surplus period is described. Factors considered include reduction of peak period demand and electric utility load problems and establishment of favorable economics for district heating and cooling systems for commercialization of the technology. The initial thrust of the STES Program toward utilization of ground water systems (aquifers) for thermal energy storage is emphasized.

  7. Fabrication and characterization of a sandpaper-based flexible energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Shieh, Jen-Yu; Wu, Cheng-Hung; Tsai, Sung-Ying [Institute of Electro-Optical and Materials Science, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China); Yu, Hsin Her, E-mail: hhyu@nfu.edu.tw [Department of Biotechnology, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China)

    2016-02-28

    . Electrochemical analysis shows excellent cycle stability and flexibility of the fine-sandpaper-based supercapacitor. Because of the simple and low-cost assembly of this flexible and lightweight supercapacitor, it has potential applications in many energy storage fields, including wearable electronics and flexible products.

  8. Energy storage for power systems

    CERN Document Server

    Ter-Gazarian, Andrei

    2011-01-01

    The supply of energy from primary sources is not constant and rarely matches the pattern of demand from consumers. Electricity is also difficult to store in significant quantities. Therefore, secondary storage of energy is essential to increase generation capacity efficiency and to allow more substantial use of renewable energy sources that only provide energy intermittently. Lack of effective storage has often been cited as a major hurdle to substantial introduction of renewable energy sources into the electricity supply network.This 2nd edition, without changing the existing structure of the

  9. Energy storage system for a pulsed DEMO

    International Nuclear Information System (INIS)

    Lucas, J.; Cortes, M.; Mendez, P.; Hayward, J.; Maisonnier, D.

    2007-01-01

    Several designs have been proposed for the DEMO fusion reactor. Some of them are working in a non-steady state mode. Since a power plant should be able to deliver to the grid a constant power, this challenge must be solved. Energy storage is required at a level of 250 MWh e with the capability of delivering a power of 1 GWe. A review of different technologies for energy storage is made. Thermal energy storage (TES), fuel cells and other hydrogen storage, compressed air storage, water pumping, batteries, flywheels and supercapacitors are the most promising solutions to energy storage. Each one is briefly described in the paper, showing its basis, features, advantages and disadvantages for this application. The conclusion of the review is that, based on existing technology, thermal energy storage using molten salts and a system based on hydrogen storage are the most promising candidates to meet the requirements of a pulsed DEMO. These systems are investigated in more detail together with an economic assessment of each

  10. The Role of Soya Oil Ester in Water-Based PCM for Low Temperature Cool Energy Storage

    Directory of Open Access Journals (Sweden)

    I. M. Rasta

    2016-01-01

    Full Text Available This study focuses on the preparation of the water-based phase change material (PCM with very small soya oil solution for low temperature latent heat thermal energy storage (LHTES. Soya oil ester is soluble very well in water and acts as nucleating agent for a novel solid-liquid PCM candidate that is suitable for low temperature cool storage in the range between −9°C and −6°C. Thermal energy storage properties of the water with very small soya oil ester solution were measured by T-history method. The experimental results show that very small amount of soya oil ester in water can lower the freezing point and trigger ice nucleation for elimination of the supercooling degree. The phase transition temperatures of the water-based PCMs with soya oil as nucleate agent were lower than those of individual water. The thermal properties make it potential PCM for LHTES systems used in low temperature cool energy storage applications.

  11. Comparing energy storage options for renewable energy integration

    DEFF Research Database (Denmark)

    Østergaard, Poul Alberg

    -inclusive 100% renewable energy scenario developed for the Danish city Aalborg based on wind power, bio-resources and low-temperature geothermal heat. The paper investigates the system impact of different types of energy storage systems including district heating storage, biogas storage and electricity storage......Increasing penetrations of fluctuating energy sources for electricity generation, heating, cooling and transportation increase the need for flexibility of the energy system to accommodate the fluctuations of these energy sources. Controlling production, controlling demand and utilizing storage...... options are the three general categories of measures that may be applied for ensuring balance between production and demand, however with fluctuating energy sources, options are limited, and flexible demand has also demonstrated limited perspective. This paper takes its point of departure in an all...

  12. Storage to Energy Calculator

    NARCIS (Netherlands)

    Taal, A.; Makkes, M.X.; Grosso, P.

    2014-01-01

    Computational and storage tasks can nowadays be offloaded among data centers, in order to optimize costs and or performance. We set out to investigate what are the environmental effects, namely the total CO2 emission, of such offloading. We built models for the various components present in these

  13. Lih thermal energy storage device

    Science.gov (United States)

    Olszewski, Mitchell; Morris, David G.

    1994-01-01

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

  14. Optimal Design and Operation Management of Battery-Based Energy Storage Systems (BESS) in Microgrids

    DEFF Research Database (Denmark)

    Anvari-Moghaddam, Amjad; Dulout, Jeremy; Alonso, Corinne

    2017-01-01

    avoiding high price spikes. Moreover, storage devices can be used as an effective mechanism for shaping the daily load curve in order to reduce electricity bills of consumers. In other words, application of ESSs will enable better utilization of distributed energy sources and provide higher controllability...... at supply/demand side which is helpful for load levelling or peak shaving purposes. Last but not least, ESSs can provide frequency regulation services in offgrid locations where there is a strong need to meet the power balance in different operating conditions. Each of the abovementioned applications...

  15. Piezoelectric-based electrical energy harvesting and storage methods and electronics for munitions

    Science.gov (United States)

    Rastegar, J.; Pereira, C.; Ervin, M.; Feng, D.

    2014-04-01

    The U.S. Armament Research development Center (ARDEC) and the Army Research Laboratories in Adelphi, Maryland, and their small business collaborator (Omnitek Partners, LLC) have been developing alternatives to current reserve batteries for certain munitions applications. It is shown that using a novel passive method, efficiency of over 70 percent could be achieved in the transfer of generated electrical charges to appropriate selected storage mediums. The paper also describes the development of test-beds to simulate electrical charge generation of the energy harvesting power sources during the firing and the flight for use in the design and evaluation of the collection electronics.

  16. University of Arizona Compressed Air Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Joseph [Univ. of Arizona, Tucson, AZ (United States); Muralidharan, Krishna [Univ. of Arizona, Tucson, AZ (United States)

    2012-12-31

    Boiled down to its essentials, the grant’s purpose was to develop and demonstrate the viability of compressed air energy storage (CAES) for use in renewable energy development. While everyone agrees that energy storage is the key component to enable widespread adoption of renewable energy sources, the development of a viable scalable technology has been missing. The Department of Energy has focused on expanded battery research and improved forecasting, and the utilities have deployed renewable energy resources only to the extent of satisfying Renewable Portfolio Standards. The lack of dispatchability of solar and wind-based electricity generation has drastically increased the cost of operation with these components. It is now clear that energy storage coupled with accurate solar and wind forecasting make up the only combination that can succeed in dispatchable renewable energy resources. Conventional batteries scale linearly in size, so the price becomes a barrier for large systems. Flow batteries scale sub-linearly and promise to be useful if their performance can be shown to provide sufficient support for solar and wind-base electricity generation resources. Compressed air energy storage provides the most desirable answer in terms of scalability and performance in all areas except efficiency. With the support of the DOE, Tucson Electric Power and Science Foundation Arizona, the Arizona Research Institute for Solar Energy (AzRISE) at the University of Arizona has had the opportunity to investigate CAES as a potential energy storage resource.

  17. Southern company energy storage study :

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, James; Bhatnagar, Dhruv; Black, Clifton; Jenkins, Kip

    2013-03-01

    This study evaluates the business case for additional bulk electric energy storage in the Southern Company service territory for the year 2020. The model was used to examine how system operations are likely to change as additional storage is added. The storage resources were allowed to provide energy time shift, regulation reserve, and spinning reserve services. Several storage facilities, including pumped hydroelectric systems, flywheels, and bulk-scale batteries, were considered. These scenarios were tested against a range of sensitivities: three different natural gas price assumptions, a 15% decrease in coal-fired generation capacity, and a high renewable penetration (10% of total generation from wind energy). Only in the elevated natural gas price sensitivities did some of the additional bulk-scale storage projects appear justifiable on the basis of projected production cost savings. Enabling existing peak shaving hydroelectric plants to provide regulation and spinning reserve, however, is likely to provide savings that justify the project cost even at anticipated natural gas price levels. Transmission and distribution applications of storage were not examined in this study. Allowing new storage facilities to serve both bulk grid and transmission/distribution-level needs may provide for increased benefit streams, and thus make a stronger business case for additional storage.

  18. Energy Storage System for a Pulsed DEMO

    International Nuclear Information System (INIS)

    Lucas, J.; Cortes, M.; Mendez, P.; Maisonnier, D.; Hayward, J.

    2006-01-01

    Several designs have been proposed for DEMO, some of which will operate in pulsed mode. Since a fusion power plant will be required to deliver continuous output, this challenge must be solved. For the reference DEMO, energy storage is required at a level of 250 MWhe with a capability of delivering a power of 1 GWe. Although DEMO is scheduled to be built in about 30 years, the design of the energy storage system must be based on current technology, focusing on commercially available products and on their expected future trends. From a thorough review of the different technologies available, thermal energy storage, compressed air energy storage, water pumping, fuel cells, batteries, flywheels and ultracapacitors are the most promising solutions to energy storage for a pulsed DEMO. An outline of each of these technologies is described in the paper, showing its basis, features, advantages and disadvantages for this application. Following this review, the most suitable methods capable of storing the required energy are examined. Fuel cells are not suitable due to the power requirement. Compressed air energy storage has a lower efficiency than the required one. Thermal energy storage, based on molten salts, so more energy can be stored with a better efficiency, and water pumping are shown as the main solutions, based on existing technology. However, those are not the only solutions capable of solving our challenge. Hydrogen production, using water electrolysis, hydrogen storage and combustion in a combined cycle can achieve our energy and power requirements with an acceptable efficiency. All these solutions are studied in detail and described, evaluating their current cost and efficiency in order to compare them all. (author)

  19. Improving wind power quality with energy storage

    OpenAIRE

    Rasmussen, Claus Nygaard

    2009-01-01

    The results of simulation of the influence of energy storage on wind power quality are presented. Simulations are done using a mathematical model of energy storage. Results show the relation between storage power and energy, and the obtained increase in minimum available power from the combination of wind and storage. The introduction of storage enables smoothening of wind power on a timescale proportional to the storage energy. Storage does not provide availability of wind power at all times...

  20. Multi-objective optimization and exergoeconomic analysis of a combined cooling, heating and power based compressed air energy storage system

    International Nuclear Information System (INIS)

    Yao, Erren; Wang, Huanran; Wang, Ligang; Xi, Guang; Maréchal, François

    2017-01-01

    Highlights: • A novel tri-generation based compressed air energy storage system. • Trade-off between efficiency and cost to highlight the best compromise solution. • Components with largest irreversibility and potential improvements highlighted. - Abstract: Compressed air energy storage technologies can improve the supply capacity and stability of the electricity grid, particularly when fluctuating renewable energies are massively connected. While incorporating the combined cooling, heating and power systems into compressed air energy storage could achieve stable operation as well as efficient energy utilization. In this paper, a novel combined cooling, heating and power based compressed air energy storage system is proposed. The system combines a gas engine, supplemental heat exchangers and an ammonia-water absorption refrigeration system. The design trade-off between the thermodynamic and economic objectives, i.e., the overall exergy efficiency and the total specific cost of product, is investigated by an evolutionary multi-objective algorithm for the proposed combined system. It is found that, with an increase in the exergy efficiency, the total product unit cost is less affected in the beginning, while rises substantially afterwards. The best trade-off solution is selected with an overall exergy efficiency of 53.04% and a total product unit cost of 20.54 cent/kWh, respectively. The variation of decision variables with the exergy efficiency indicates that the compressor, turbine and heat exchanger preheating the inlet air of turbine are the key equipment to cost-effectively pursuit a higher exergy efficiency. It is also revealed by an exergoeconomic analysis that, for the best trade-off solution, the investment costs of the compressor and the two heat exchangers recovering compression heat and heating up compressed air for expansion should be reduced (particularly the latter), while the thermodynamic performance of the gas engine need to be improved

  1. Storage Free Smart Energy Management for Frequency Control in a Diesel-PV-Fuel Cell-Based Hybrid AC Microgrid.

    Science.gov (United States)

    Sekhar, P C; Mishra, S

    2016-08-01

    This paper proposes a novel, smart energy management scheme for a microgrid, consisting of a diesel generator and power electronic converter interfaced renewable energy-based generators, such as photovoltaic (PV) and fuel cell, for frequency regulation without any storage. In the proposed strategy, output of the PV is controlled in coordination with other generators using neurofuzzy controller, either only for transient frequency regulation or for both transient and steady-state frequency regulation, depending on the load demand, thereby eliminating the huge storage requirements. The option of demand response control is also explored along with the generation control. For accurate and quick tracking of maximum power point and its associated reserve power from the PV generator, this paper also proposes a novel adaptive-predictor-corrector-based tracking mechanism.

  2. Photovoltaic power systems energy storage

    International Nuclear Information System (INIS)

    Buldini, P.L.

    1991-01-01

    Basically, the solar photovoltaic power system consists of: Array of solar panels; Charge/voltage stabilizer; Blocking diode and Storage device. The storage device is a very important part of the system due to the necessity to harmonize the inevitable time shift between energy supply and demand. As energy storage, different devices can be utilized, such as hydropumping, air or other gas compression, flywheel, superconducting magnet, hydrogen generation and so on, but actually secondary (rechargeable) electrochemical cells appear to be the best storage device, due to the direct use for recharge of the d.c. current provided by the solar panels, without any intermediate step of energy transformation and its consequent loss of efficiency

  3. Microencapsulation of metal-based phase change material for high-temperature thermal energy storage.

    Science.gov (United States)

    Nomura, Takahiro; Zhu, Chunyu; Sheng, Nan; Saito, Genki; Akiyama, Tomohiro

    2015-03-13

    Latent heat storage using alloys as phase change materials (PCMs) is an attractive option for high-temperature thermal energy storage. Encapsulation of these PCMs is essential for their successful use. However, so far, technology for producing microencapsulated PCMs (MEPCMs) that can be used above 500°C has not been established. Therefore, in this study, we developed Al-Si alloy microsphere MEPCMs covered by α-Al2O3 shells. The MEPCM was prepared in two steps: (1) the formation of an AlOOH shell on the PCM particles using a boehmite treatment, and (2) heat-oxidation treatment in an O2 atmosphere to form a stable α-Al2O3 shell. The MEPCM presented a melting point of 573°C and latent heat of 247 J g(-1). The cycling performance showed good durability. These results indicated the possibility of using MEPCM at high temperatures. The MEPCM developed in this study has great promise in future energy and chemical processes, such as exergy recuperation and process intensification.

  4. Copper Oxide Thin Films through Solution Based Methods for Electrical Energy Conversion and Storage

    Science.gov (United States)

    Zhu, Changqiong

    Copper oxides (Cu2O and CuO), composed of non-toxic and earth abundant elements, are promising materials for electrical energy generation and storage devices. Solution based techniques for creating thin films of these materials, such as electrodeposition, are important to understand and develop because of their potential for realizing substantial energy savings compared to traditional fabrication methods. Cuprous oxide (Cu2O), with its direct band gap, is a p-type semiconductor that is well suited for creating solution-processed photovoltaic devices (solar cells); several key advancements made toward this application are the primary focus of this thesis. Electrodeposition of single-phase, crystalline Cu2O thin films is demonstrated using previously unexplored, acidic lactate/Cu2+ solutions, which has provided additional understanding of the impacts of growth solution chemistry on film formation. The influence of pH on the resulting Cu2O thin film properties is revealed by using the same ligand (sodium lactate) at various solution pH values. Cu2O films grown from acidic lactate solutions can exhibit a distinctive flowerlike, dendritic morphology, in contrast to the faceted, dense films obtained using alkaline lactate solutions. Relative speciation distributions of the various metal complex ions present under different growth conditions are calculated using reported equilibrium association constants and experimentally supported by UV-Visible absorption spectroscopy. Dependence of thin film morphology on the lactate/Cu2+ molar ratio and applied potential is described. Cu2O/eutectic gallium-indium Schottky junction devices are formed and devices are tested under monochromatic green LED illumination. Further surface examination of the Cu2O films using X-ray photoelectron spectroscopy (XPS) reveals the fact that films grown from acidic lactate solution with a small lactate/Cu2+ molar ratio, which exhibit improved photovoltaic performance compared to films grown from

  5. TEXT Energy Storage System

    International Nuclear Information System (INIS)

    Weldon, W.F.; Rylander, H.G.; Woodson, H.H.

    1977-01-01

    The Texas Experimental Tokamak (TEXT) Enery Storage System, designed by the Center for Electromechanics (CEM), consists of four 50 MJ, 125 V homopolar generators and their auxiliaries and is designed to power the toroidal and poloidal field coils of TEXT on a two-minute duty cycle. The four 50 MJ generators connected in series were chosen because they represent the minimum cost configuration and also represent a minimal scale up from the successful 5.0 MJ homopolar generator designed, built, and operated by the CEM

  6. A High Temperature Electrochemical Energy Storage System Based on Sodium Beta-Alumina Solid Electrolyte (Base)

    Energy Technology Data Exchange (ETDEWEB)

    Anil Virkar

    2008-03-31

    This report summarizes the work done during the period September 1, 2005 and March 31, 2008. Work was conducted in the following areas: (1) Fabrication of sodium beta{double_prime} alumina solid electrolyte (BASE) using a vapor phase process. (2) Mechanistic studies on the conversion of {alpha}-alumina + zirconia into beta{double_prime}-alumina + zirconia by the vapor phase process. (3) Characterization of BASE by X-ray diffraction, SEM, and conductivity measurements. (4) Design, construction and electrochemical testing of a symmetric cell containing BASE as the electrolyte and NaCl + ZnCl{sub 2} as the electrodes. (5) Design, construction, and electrochemical evaluation of Na/BASE/ZnCl{sub 2} electrochemical cells. (6) Stability studies in ZnCl{sub 2}, SnCl{sub 2}, and SnI{sub 4} (7) Design, assembly and testing of planar stacks. (8) Investigation of the effect of porous surface layers on BASE on cell resistance. The conventional process for the fabrication of sodium ion conducting beta{double_prime}-alumina involves calcination of {alpha}-alumina + Na{sub 2}CO{sub 3} + LiNO{sub 3} at 1250 C, followed by sintering powder compacts in sealed containers (platinum or MgO) at {approx}1600 C. The novel vapor phase process involves first sintering a mixture of {alpha}-alumina + yttria-stabilized zirconia (YSZ) into a dense ceramic followed by exposure to soda vapor at {approx}1450 C to convert {alpha}-alumina into beta{double_prime}-alumina. The vapor phase process leads to a high strength BASE, which is also resistant to moisture attack, unlike BASE made by the conventional process. The PI is the lead inventor of the process. Discs and tubes of BASE were fabricated in the present work. In the conventional process, sintering of BASE is accomplished by a transient liquid phase mechanism wherein the liquid phase contains NaAlO{sub 2}. Some NaAlO{sub 2} continues to remain at grain boundaries; and is the root cause of its water sensitivity. In the vapor phase process, Na

  7. High density energy storage capacitor

    International Nuclear Information System (INIS)

    Whitham, K.; Howland, M.M.; Hutzler, J.R.

    1979-01-01

    The Nova laser system will use 130 MJ of capacitive energy storage and have a peak power capability of 250,000 MW. This capacitor bank is a significant portion of the laser cost and requires a large portion of the physical facilities. In order to reduce the cost and volume required by the bank, the Laser Fusion Program funded contracts with three energy storage capacitor producers: Aerovox, G.E., and Maxwell Laboratories, to develop higher energy density, lower cost energy storage capacitors. This paper describes the designs which resulted from the Aerovox development contract, and specifically addresses the design and initial life testing of a 12.5 kJ, 22 kV capacitor with a density of 4.2 J/in 3 and a projected cost in the range of 5 cents per joule

  8. Implementation and Control of a Residential Electrothermal Microgrid Based on Renewable Energies, a Hybrid Storage System and Demand Side Management

    Directory of Open Access Journals (Sweden)

    Julio Pascual

    2014-01-01

    Full Text Available This paper proposes an energy management strategy for a residential electrothermal microgrid, based on renewable energy sources. While grid connected, it makes use of a hybrid electrothermal storage system, formed by a battery and a hot water tank along with an electrical water heater as a controllable load, which make possible the energy management within the microgrid. The microgrid emulates the operation of a single family home with domestic hot water (DHW consumption, a heating, ventilation and air conditioning (HVAC system as well as the typical electric loads. An energy management strategy has been designed which optimizes the power exchanged with the grid profile in terms of peaks and fluctuations, in applications with high penetration levels of renewables. The proposed energy management strategy has been evaluated and validated experimentally in a full scale residential microgrid built in our Renewable Energy Laboratory, by means of continuous operation under real conditions. The results show that the combination of electric and thermal storage systems with controllable loads is a promising technology that could maximize the penetration level of renewable energies in the electric system.

  9. Energy storage for sustainable microgrid

    CERN Document Server

    Gao, David Wenzhong

    2015-01-01

    Energy Storage for Sustainable Microgrid addresses the issues related to modelling, operation and control, steady-state and dynamic analysis of microgrids with ESS. This book discusses major electricity storage technologies in depth along with their efficiency, lifetime cycles, environmental benefits and capacity, so that readers can envisage which type of storage technology is best for a particular microgrid application. This book offers solutions to numerous difficulties such as choosing the right ESS for the particular microgrid application, proper sizing of ESS for microgrid, as well as

  10. Thermal Energy Storage: Fourth Annual Review Meeting

    Science.gov (United States)

    1980-01-01

    The development of low cost thermal energy storage technologies is discussed in terms of near term oil savings, solar energy applications, and dispersed energy systems for energy conservation policies. Program definition and assessment and research and technology development are considered along with industrial storage, solar thermal power storage, building heating and cooling, and seasonal thermal storage. A bibliography on seasonal thermal energy storage emphasizing aquifer thermal energy is included.

  11. Performance of Loaded Thermal Storage Unit with a Commercial Phase Change Materials based on Energy and Exergy Analysis

    Directory of Open Access Journals (Sweden)

    Abdullah Nasrallh Olimat

    2017-11-01

    Article History: Received July 6th 2017; Received in revised form September 15th 2017; Accepted 25th Sept 2017; Available online How to Cite This Article: Olimat, A.N., Awad, A.S., Al-Gathain, F.M., and Shaban, N.A.. (2017 Performance of Loaded Thermal Storage Unit With A Commercial Phase Change Materials Based on Energy and Exergy Analysis. International Journal of Renewable Energy Develeopment, 6(3,283-290. https://doi.org/10.14710/ijred.6.3.283-290

  12. Melting/solidification characteristics of paraffin based nanocomposite for thermal energy storage applications

    Directory of Open Access Journals (Sweden)

    Lokesh Selvam

    2017-01-01

    Full Text Available The present work aimed to investigate the melting and solidification characteristics of nanoparticle enhanced phase change material (NEPCM. The NEPCM were prepared using paraffin as the phase change material and multiwall carbon nanotube (MWCNT as the nanomaterial without using any dispersant. Thermal conductivity of the NEPCM was measured with respect to temperature and the measured data showed higher enhancement than the phase change material both in liquid and solid state, due to inherent high conductive and the continuous networking of the MWCNT. A reduction in solidification and melting time of 42% and 29% was achieved in the case of NEPCM with 0.9% and 0.3%, respectively. It is concluded that enhanced heat transfer characteristics of NEPCM is highly beneficial towards design and development of efficient thermal energy storage system for various applications.

  13. WAMS Based Damping Control of Inter-area Oscillations Employing Energy Storage System

    Directory of Open Access Journals (Sweden)

    MA, J.

    2012-05-01

    Full Text Available This paper presents a systematic design procedure for a wide-area damping controller (WADC employing Energy Storage Systems (ESSs. The WADC is aimed at enhancing the damping of multiple inter-area modes in a large scale power system. Firstly, geometric measures of controllability and obsevability are used to select the control locations for ESSs and most effective stabilizing signals, respectively. Then, the WADC coordinates these signals to achieve multiple-input-multiple-output (MIMO controllers with the least Frobenius norm feedback gain matrix. The simulation results of frequency and time domains verify the effectiveness of the wide-area damping controller for various operating conditions. Furthermore, the robustness of the wide-area damping controller is also tested with respect to time delay and uncertainty of models.

  14. Phenolic resin-based porous carbons for adsorption and energy storage applications

    Science.gov (United States)

    Wickramaratne, Nilantha P.

    The main objective of this dissertation research is to develop phenolic resin based carbon materials for range of applications by soft-templating and Stober-like synthesis strategies. Applications Studied in this dissertation are adsorption of CO2, bio-molecular and heavy metal ions, and energy storage devices. Based on that, our goal is to design carbon materials with desired pore structure, high surface area, graphitic domains, incorporated metal nanoparticles, and specific organic groups and heteroatoms. In this dissertation the organic-organic self-assembly of phenolic resins and triblock copolymers under acidic conditions will be used to obtain mesoporous carbons/carbon composites and Stober-like synthesis involving phenolic resins under basic condition will be used to prepare polymer/carbon particles and their composites. The structure of this dissertation consists of an introductory chapter (Chapter 1) discussing the general synthesis of carbon materials, particularly the soft-templating strategy and Stober-like carbon synthesis. Also, Chapter 1 includes a brief outline of applications namely adsorption of CO2, biomolecule and heavy metal ions, and supercapacitors. Chapter 2 discusses the techniques used for characterization of the carbon materials studied. This chapter starts with nitrogen adsorption analysis, which is used to measure the specific surface area, pore volume, distribution of pore sizes, and pore width. In addition to nitrogen adsorption, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution thermogravimetric analysis (HR-TGA), cyclic voltammetry (CV) and CHNS elemental analysis (EA) are mentioned too. Chapter 3 is focused on carbon materials for CO2 adsorption. There are different types of porous solid materials such as silicate, MOFs, carbons, and zeolites studied for CO2 adsorption. However, the carbon based materials are considered to be the best candidates for CO 2 adsorption to the industrial point of

  15. Value of Energy Storage for Grid Applications

    Energy Technology Data Exchange (ETDEWEB)

    Denholm, P.; Jorgenson, J.; Hummon, M.; Jenkin, T.; Palchak, D.; Kirby, B.; Ma, O.; O' Malley, M.

    2013-05-01

    This analysis evaluates several operational benefits of electricity storage, including load-leveling, spinning contingency reserves, and regulation reserves. Storage devices were simulated in a utility system in the western United States, and the operational costs of generation was compared to the same system without the added storage. This operational value of storage was estimated for devices of various sizes, providing different services, and with several sensitivities to fuel price and other factors. Overall, the results followed previous analyses that demonstrate relatively low value for load-leveling but greater value for provision of reserve services. The value was estimated by taking the difference in operational costs between cases with and without energy storage and represents the operational cost savings from deploying storage by a traditional vertically integrated utility. The analysis also estimated the potential revenues derived from a merchant storage plant in a restructured market, based on marginal system prices. Due to suppression of on-/off-peak price differentials and incomplete capture of system benefits (such as the cost of power plant starts), the revenue obtained by storage in a market setting appears to be substantially less than the net benefit provided to the system. This demonstrates some of the additional challenges for storage deployed in restructured energy markets.

  16. Battery energy storage system

    NARCIS (Netherlands)

    Tol, C.S.P.; Evenblij, B.H.

    2009-01-01

    The ability to store electrical energy adds several interesting features to a ships distribution network, as silent power, peak shaving and a ride through in case of generator failure. Modern intrinsically safe Li-ion batteries bring these within reach. For this modern lithium battery applications

  17. A Learning Based Precool Algorithm for Utilization of Foodstuff as Thermal Energy Storage

    DEFF Research Database (Denmark)

    Vinther, Kasper; Rasmussen, Henrik; Izadi-Zamanabadi, Roozbeh

    2013-01-01

    degradation. A learning based algorithm is proposed in this paper, which precools the foodstuff in an anticipatory manner based on the saturation level in the system on recent days. The method is evaluated using a simulation model of a supermarket refrigeration system and simulations show that thermal energy...

  18. Optimal Sizing and Placement of Battery Energy Storage in Distribution System Based on Solar Size for Voltage Regulation

    Energy Technology Data Exchange (ETDEWEB)

    Nazaripouya, Hamidreza [Univ. of California, Los Angeles, CA (United States); Wang, Yubo [Univ. of California, Los Angeles, CA (United States); Chu, Peter [Univ. of California, Los Angeles, CA (United States); Pota, Hemanshu R. [Univ. of California, Los Angeles, CA (United States); Gadh, Rajit [Univ. of California, Los Angeles, CA (United States)

    2016-07-26

    This paper proposes a new strategy to achieve voltage regulation in distributed power systems in the presence of solar energy sources and battery storage systems. The goal is to find the minimum size of battery storage and its corresponding location in the network based on the size and place of the integrated solar generation. The proposed method formulates the problem by employing the network impedance matrix to obtain an analytical solution instead of using a recursive algorithm such as power flow. The required modifications for modeling the slack and PV buses (generator buses) are utilized to increase the accuracy of the approach. The use of reactive power control to regulate the voltage regulation is not always an optimal solution as in distribution systems R/X is large. In this paper the minimum size and the best place of battery storage is achieved by optimizing the amount of both active and reactive power exchanged by battery storage and its gridtie inverter (GTI) based on the network topology and R/X ratios in the distribution system. Simulation results for the IEEE 14-bus system verify the effectiveness of the proposed approach.

  19. Development of graphite foam infiltrated with MgCl 2 for a latent heat based thermal energy storage (LHTES) system

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Dileep; Kim, Taeil; Zhao, Weihuan; Yu, Wenhua; France, David M.

    2016-08-01

    Thermal energy storage (TES) systems that are compatible with high temperature power cycles for concentrating solar power (CSP) require high temperature media for transporting and storing thermal energy. To that end, TES systems have been proposed based on the latent heat of fusion of the phase change materials (PCMs). However, PCMs have relatively low thermal conductivities. In this paper, use of high-thermal-conductivity graphite foam infiltrated with a PCM (MgCl2) has been investigated as a potential TES system. Graphite foams with two porosities were infiltrated with MgCl2. The infiltrated composites were evaluated for density, heat of fusion, melting/freezing temperatures, and thermal diffusivities. Estimated thermal conductivities of MgCl2/graphite foam composites were significantly higher than those of MgCl2 alone over the measured temperature range. Furthermore, heat of fusion, melting/freezing temperatures, and densities showed comparable values to those of pure MgCl2. Results of this study indicate that MgCl2/graphite foam composites show promise as storage media for a latent heat thermal energy storage system for CSP applications.

  20. Thermal energy storage flight experiments

    Science.gov (United States)

    Namkoong, D.

    1989-01-01

    Consideration is given to the development of an experimental program to study heat transfer, energy storage, fluid movement, and void location under microgravity. Plans for experimental flight packages containing Thermal Energy Storage (TES) material applicable for advanced solar heat receivers are discussed. Candidate materials for TES include fluoride salts, salt eutectics, silicides, and metals. The development of a three-dimensional computer program to describe TES material behavior undergoing melting and freezing under microgravity is also discussed. The TES experiment concept and plans for ground and flight tests are outlined.

  1. Bioinspired fractal electrodes for solar energy storages.

    Science.gov (United States)

    Thekkekara, Litty V; Gu, Min

    2017-03-31

    Solar energy storage is an emerging technology which can promote the solar energy as the primary source of electricity. Recent development of laser scribed graphene electrodes exhibiting a high electrical conductivity have enabled a green technology platform for supercapacitor-based energy storage, resulting in cost-effective, environment-friendly features, and consequent readiness for on-chip integration. Due to the limitation of the ion-accessible active porous surface area, the energy densities of these supercapacitors are restricted below ~3 × 10 -3  Whcm -3 . In this paper, we demonstrate a new design of biomimetic laser scribed graphene electrodes for solar energy storage, which embraces the structure of Fern leaves characterized by the geometric family of space filling curves of fractals. This new conceptual design removes the limit of the conventional planar supercapacitors by significantly increasing the ratio of active surface area to volume of the new electrodes and reducing the electrolyte ionic path. The attained energy density is thus significantly increased to ~10 -1  Whcm -3 - more than 30 times higher than that achievable by the planar electrodes with ~95% coulombic efficiency of the solar energy storage. The energy storages with these novel electrodes open the prospects of efficient self-powered and solar-powered wearable, flexible and portable applications.

  2. Bioinspired fractal electrodes for solar energy storages

    Science.gov (United States)

    Thekkekara, Litty V.; Gu, Min

    2017-03-01

    Solar energy storage is an emerging technology which can promote the solar energy as the primary source of electricity. Recent development of laser scribed graphene electrodes exhibiting a high electrical conductivity have enabled a green technology platform for supercapacitor-based energy storage, resulting in cost-effective, environment-friendly features, and consequent readiness for on-chip integration. Due to the limitation of the ion-accessible active porous surface area, the energy densities of these supercapacitors are restricted below ~3 × 10-3 Whcm-3. In this paper, we demonstrate a new design of biomimetic laser scribed graphene electrodes for solar energy storage, which embraces the structure of Fern leaves characterized by the geometric family of space filling curves of fractals. This new conceptual design removes the limit of the conventional planar supercapacitors by significantly increasing the ratio of active surface area to volume of the new electrodes and reducing the electrolyte ionic path. The attained energy density is thus significantly increased to ~10-1 Whcm-3- more than 30 times higher than that achievable by the planar electrodes with ~95% coulombic efficiency of the solar energy storage. The energy storages with these novel electrodes open the prospects of efficient self-powered and solar-powered wearable, flexible and portable applications.

  3. The stationary storage of energy. Available technologies and CEA researches

    International Nuclear Information System (INIS)

    2012-01-01

    After a discussion of the main challenges related to the stationary storage of energy, this publication proposes an overview of the different available technologies: plant for transfer of energy by pumping, compressed air, energy flywheels, hydrogen, lithium-ion battery, redox-flow battery, thermal storage by sensitive heat, thermal-chemical storage coupled to a thermal solar system, thermal storage by phase change, superconductive inductance storage, super-capacitors. It discusses the criteria of choice of storage technology, either for electric energy storage or for heat storage. It proposes an overview of researches performed within the CEA on storage systems: electrochemical, thermal, and hydrogen-based storages. The final chapter addresses current fundamental researches on storage in the field of lithium-ion batteries, hydrogen as a fuel, and thermoelectricity

  4. NV energy electricity storage valuation :

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, James F.; Bhatnagar, Dhruv; Samaan, Nader; Jin, Chunlian

    2013-06-01

    This study examines how grid-level electricity storage may benefit the operations of NV Energy, and assesses whether those benefits are likely to justify the cost of the storage system. To determine the impact of grid-level storage, an hourly production cost model of the Nevada Balancing Authority ("BA") as projected for 2020 was created. Storage was found to add value primarily through the provision of regulating reserve. Certain storage resources were found likely to be cost-effective even without considering their capacity value, as long as their effectiveness in providing regulating reserve was taken into account. Giving fast resources credit for their ability to provide regulating reserve is reasonable, given the adoption of FERC Order 755 ("Pay-for-performance"). Using a traditional five-minute test to determine how much a resource can contribute to regulating reserve does not adequately value fast-ramping resources, as the regulating reserve these resources can provide is constrained by their installed capacity. While an approximation was made to consider the additional value provided by a fast-ramping resource, a more precise valuation requires an alternate regulating reserve methodology. Developing and modeling a new regulating reserve methodology for NV Energy was beyond the scope of this study, as was assessing the incremental value of distributed storage.

  5. Optimal Scheduling of a Battery-Based Energy Storage System for a Microgrid with High Penetration of Renewable Sources

    DEFF Research Database (Denmark)

    Dulout, Jeremy; Hernández, Adriana Carolina Luna; Anvari-Moghaddam, Amjad

    2017-01-01

    A new scheduling method is proposed to manage efficiently the integration of renewable sources in microgrids (MGs) with energy storage systems (ESSs). The purpose of this work is to take into account the main stress factors influencing the ageing mechanisms of a battery energy storage system (BES...

  6. Distributed energy systems with wind power and energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Korpaas, Magnus

    2004-07-01

    The topic of this thesis is the study of energy storage systems operating with wind power plants. The motivation for applying energy storage in this context is that wind power generation is intermittent and generally difficult to predict, and that good wind energy resources are often found in areas with limited grid capacity. Moreover, energy storage in the form of hydrogen makes it possible to provide clean fuel for transportation. The aim of this work has been to evaluate how local energy storage systems should be designed and operated in order to increase the penetration and value of wind power in the power system. Optimization models and sequential and probabilistic simulation models have been developed for this purpose. Chapter 3 presents a sequential simulation model of a general wind hydrogen energy system. Electrolytic hydrogen is used either as a fuel for transportation or for power generation in a stationary fuel cell. The model is useful for evaluating how hydrogen storage can increase the penetration of wind power in areas with limited or no transmission capacity to the main grid. The simulation model is combined with a cost model in order to study how component sizing and choice of operation strategy influence the performance and economics of the wind-hydrogen system. If the stored hydrogen is not used as a separate product, but merely as electrical energy storage, it should be evaluated against other and more energy efficient storage options such as pumped hydro and redox flow cells. A probabilistic model of a grid-connected wind power plant with a general energy storage unit is presented in chapter 4. The energy storage unit is applied for smoothing wind power fluctuations by providing a firm power output to the grid over a specific period. The method described in the chapter is based on the statistical properties of the wind speed and a general representation of the wind energy conversion system and the energy storage unit. This method allows us to

  7. 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.

  8. Recent advances in nanostructured Nb-based oxides for electrochemical energy storage

    Science.gov (United States)

    Yan, Litao; Rui, Xianhong; Chen, Gen; Xu, Weichuan; Zou, Guifu; Luo, Hongmei

    2016-04-01

    For the past five years, nanostructured niobium-based oxides have emerged as one of the most prominent materials for batteries, supercapacitors, and fuel cell technologies, for instance, TiNb2O7 as an anode for lithium-ion batteries (LIBs), Nb2O5 as an electrode for supercapacitors (SCs), and niobium-based oxides as chemically stable electrochemical supports for fuel cells. Their high potential window can prevent the formation of lithium dendrites, and their rich redox chemistry (Nb5+/Nb4+, Nb4+/Nb3+) makes them very promising electrode materials. Their unique chemical stability under acid conditions is favorable for practical fuel-cell operation. In this review, we summarized recent progress made concerning the use of niobium-based oxides as electrodes for batteries (LIBs, sodium-ion batteries (SIBs), and vanadium redox flow batteries (VRBs)), SCs, and fuel cell applications. Moreover, crystal structures, charge storage mechanisms in different crystal structures, and electrochemical performances in terms of the specific capacitance/capacity, rate capability, and cycling stability of niobium-based oxides are discussed. Insights into the future research and development of niobium-based oxide compounds for next-generation electrochemical devices are also presented. We believe that this review will be beneficial for research scientists and graduate students who are searching for promising electrode materials for batteries, SCs, and fuel cells.

  9. Energy loss minimization through peak shaving using energy storage

    Directory of Open Access Journals (Sweden)

    Vaiju Kalkhambkar

    2016-09-01

    Full Text Available This paper presents an optimal placement methodology of energy storage to improve energy loss minimization through peak shaving in the presence of renewable distributed generation. Storage sizing is modelled by considering the load profile and desired peak shaving. This storage is suitably divided into multiple storage units and optimally allocated at multiple sites with suitable charge discharge strategy. Thus the peak shaving for maximum loss reduction is explored here. Renewable distributed generation (RDG is modelled based on the seasonal variations of renewable resources e.g., solar or wind and these RDGs are placed at suitable locations. A high-performance Grey Wolf Optimization (GWO algorithm is applied to the proposed methodology. The results are compared with the well-known genetic algorithm. The proposed methodology is illustrated by various case studies on a 34-bus test system. Significant loss minimization is obtained by optimal location of multiple energy storage units through peak shaving.

  10. Multifunctional composites for energy storage

    Science.gov (United States)

    Shuvo, Mohammad Arif I.; Karim, Hasanul; Rajib, Md; Delfin, Diego; Lin, Yirong

    2014-03-01

    Electrochemical super-capacitors have become one of the most important topics in both academia and industry as novel energy storage devices because of their high power density, long life cycles, and high charge/discharge efficiency. Recently, there has been an increasing interest in the development of multifunctional structural energy storage devices such as structural super-capacitors for applications in aerospace, automobiles and portable electronics. These multifunctional structural super-capacitors provide lighter structures combining energy storage and load bearing functionalities. Due to their superior materials properties, carbon fiber composites have been widely used in structural applications for aerospace and automotive industries. Besides, carbon fiber has good electrical conductivity which will provide lower equivalent series resistance; therefore, it can be an excellent candidate for structural energy storage applications. Hence, this paper is focused on performing a pilot study for using nanowire/carbon fiber hybrids as building materials for structural energy storage materials; aiming at enhancing the charge/discharge rate and energy density. This hybrid material combines the high specific surface area of carbon fiber and pseudo-capacitive effect of metal oxide nanowires which were grown hydrothermally in an aligned fashion on carbon fibers. The aligned nanowire array could provide a higher specific surface area that leads to high electrode-electrolyte contact area and fast ion diffusion rates. Scanning Electron Microscopy (SEM) and XRay Diffraction (XRD) measurements were used for the initial characterization of this nanowire/carbon fiber hybrid material system. Electrochemical testing has been performed using a potentio-galvanostat. The results show that gold sputtered nanowire hybrid carbon fiber provides 65.9% better performance than bare carbon fiber cloth as super-capacitor.

  11. Research on the Orientation and Application of Distributed Energy Storage in Energy Internet

    Science.gov (United States)

    Zeng, Ming; Zhou, Pengcheng; Li, Ran; Zhou, Jingjing; Chen, Tao; Li, Zhe

    2018-01-01

    Energy storage is indispensable resources to achieve a high proportion of new energy power consumption in electric power system. As an important support to energy Internet, energy storage system can achieve a variety of energy integration operation to ensure maximum energy efficiency. In this paper, firstly, the SWOT analysis method is used to express the internal and external advantages and disadvantages of distributed energy storage participating in the energy Internet. Secondly, the function orientation of distributed energy storage in energy Internet is studied, based on which the application modes of distributed energy storage in virtual power plant, community energy storage and auxiliary services are deeply studied. Finally, this paper puts forward the development strategy of distributed energy storage which is suitable for the development of China’s energy Internet, and summarizes and prospects the application of distributed energy storage system.

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

    Science.gov (United States)

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

    2016-09-13

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

  13. Experimental Investigation on CO2 Methanation Process for Solar Energy Storage Compared to CO2-Based Methanol Synthesis

    NARCIS (Netherlands)

    Castellani, Beatrice; Gambelli, Alberto Maria; Morini, Elena; Nastasi, B.; Presciutti, Andrea; Filipponi, Mirko; Nicolini, Andrea; Rossi, Federico

    2017-01-01

    The utilization of the captured CO2 as a carbon source for the production of energy storage media offers a technological solution for overcoming crucial issues in current energy systems. Solar energy production generally does not match with energy demand because of its intermittent and

  14. Definition, analysis and experimental investigation of operation modes in hydrogen-renewable-based power plants incorporating hybrid energy storage

    International Nuclear Information System (INIS)

    Valverde, L.; Pino, F.J.; Guerra, J.; Rosa, F.

    2016-01-01

    Highlights: • A conceptual analysis of operation modes in energy storage plants is presented. • Key Performance Indicators to select operation modes are provided. • The approach has been applied to a laboratory hybrid power plant. • The methodology provides guidance for the operation of hybrid power plants. - Abstract: This paper is concerned with Operating Modes in hybrid renewable energy-based power plants with hydrogen as the intermediate energy storage medium. Six operation modes are defined according to plant topology and the possibility of operating electrolyzer and fuel cell at steady-power or partial load. A methodology for the evaluation of plant performance is presented throughout this paper. The approach includes a set of simulations over a fully validated model, which are run in order to compare the proposed operation modes in various weather conditions. Conclusions are drawn from the simulation stage using a set of Key Performance Indicators defined in this paper. This analysis yields the conclusion that certain modes are more appropriate from technical and practical standpoints when they are implemented in a real plant. From the results of the simulation assessment, selected operating modes are applied to an experimental hydrogen-based pilot plant to illustrate and validate the performance of the proposed operation modes. Experimental results confirmed the simulation study, pointing out the advantages and disadvantages of each operation mode in terms of performance and equipment durability.

  15. A Scenario-Based Approach for Energy Storage Capacity Determination in LV Grids with High PV Penetration

    DEFF Research Database (Denmark)

    Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob; Yang, Guangya

    2014-01-01

    In this paper a new method is proposed to determine the minimum energy storage required to be installed at different locations of a low voltage (LV) grid in order to prevent the overvoltage due to high residential photovoltaic (PV) penetration. The method is based on the voltage sensitivity...... with different occurrence probabilities without involving the time-series studies problems. The proposed method is capable of modeling output power of PV panels with different orientations as well as different electric vehicle (EV) charging patterns....

  16. A local energy management of a hybrid PV-storage based distributed generation for microgrids

    International Nuclear Information System (INIS)

    Choudar, Adel; Boukhetala, Djamel; Barkat, Said; Brucker, Jean-Michel

    2015-01-01

    Highlights: • The proposed system is based on photovoltaic system, batteries and ultra-capacitors. • Batteries are used as an energy source, ultra-capacitors are used as a fast power regulator. • An energy management strategy, to operate a grid connected active PV system (APS). • Different levels of the control system are studied and organized in a hierarchical control structure. • Different operating modes are explained (island, limited PV power, normal, fast recovering). - Abstract: The presented work focuses on energy management strategy, to operate a grid connected active PV system (APS) in a microgrid. A microgrid is a smart grid in a small scale which can be stand-alone or grid-tied. The proposed system is based on photovoltaic system, batteries and ultra-capacitors. Three converters are used to interface the elements of the APS to a common DC-link capacitor. The presented control strategy manages the power flow between the converters and the grid through the DC-link in order to maintain the grid power demand coming from the grid operator. Batteries are used as an energy source, to stabilize and permit the APS units to run at a constant and stable output power, damping peak surges in electricity demand and to store the excess of energy from the PV array. Ultra-capacitors are used as a fast power regulator to: limit the battery’s current, regulate the DC-link voltage when the disconnection mode occurs and to deliver a smooth power to the grid, despite primary source and load fluctuations. Several operating modes are presented to manage locally the power flows between the various sources, taking into account the state of charge of batteries (SOC), the energy level of ultra-capacitors (Lev), the available PV power and the power demand from the grid operator

  17. Aquifer thermal energy storage. International symposium: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

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

  18. Experimental characterization of a solar cooker with thermal energy storage based on solar salt

    Science.gov (United States)

    Coccia, G.; Di Nicola, G.; Tomassetti, S.; Gabrielli, G.; Chieruzzi, M.; Pierantozzi, M.

    2017-11-01

    High temperature solar cooking allows to cook food fast and with good efficiency. An unavoidable drawback of this technology is that it requires nearly clear-sky conditions. In addition, evening cooking is difficult to be accomplished, particularly on the winter season during which solar radiation availability is limited to a few hours in the afternoon in most of countries. These restrictions could be overcome using a cooker thermal storage unit (TSU). In this work, a TSU based on solar salt was studied. The unit consists of two metal concentric cylindrical vessels, connected together to form a double-walled vessel. The volume between walls was filled with a certain amount of nitrate based phase change material (solar salt). In order to characterize the TSU, a test bench used to assess solar cooker performance was adopted. Experimental load tests with the TSU were carried out to evaluate the cooker performance. The obtained preliminary results show that the adoption of the solar salt TSU seems to allow both the opportunity of evening cooking and the possibility to better stabilize the cooker temperature when sky conditions are variable.

  19. Transient performance of a thermal energy storage-based heat sink using a liquid metal as the phase change material

    International Nuclear Information System (INIS)

    Fan, Li-Wu; Wu, Yu-Yue; Xiao, Yu-Qi; Zeng, Yi; Zhang, Yi-Ling; Yu, Zi-Tao

    2016-01-01

    Highlights: • A liquid metal is adopted as the PCM in a thermal energy storage-based heat sink. • Transient performance of the heat sink is tested in comparison to an organic PCM. • The liquid metal has a similar volumetric latent heat of fusion to the organic PCM. • Outperformance of the liquid metal is found due to its higher thermal conductivity. • Liquid metals are preferred when the system weight is less important than volume. - Abstract: In this Technical Note, the use of a liquid metal, i.e., a low melting point Pb–Sn–In–Bi alloy, as the phase change material (PCM) in thermal energy storage-based heat sinks is tested in comparison to an organic PCM (1-octadecanol) having a similar melting point of ∼60 °C. The thermophysical properties of the two types of PCM are characterized, revealing that the liquid metal is much more conductive while both have nearly identical volumetric latent heat of fusion (∼215 MJ/m 3 ). By using at the same volume of 80 mL, i.e., the same energy storage capacity, the liquid metal is shown to outperform significantly over the organic PCM under the various heating powers up to 105.3 W/cm 2 . During the heating period, the use of the liquid metal leads to a remarkable extension of the effective protection time to nearly twice longer as well as a reduction of the highest overheating temperature by up to 50 °C. The cool-down period can also be shortened significantly by taking advantage of the much higher thermal conductivity of the liquid metal. These findings suggest that liquid metals could serve as a promising PCM candidate for particular applications where the volume limit is very rigorous and the penalty in weight increment is acceptable.

  20. Solar applications analysis for energy storage

    Science.gov (United States)

    Blanchard, T.

    1980-01-01

    The role of energy storage as it relates to solar energy systems is considered. Storage technologies to support solar energy applications, the status of storage technologies, requirements and specifications for storage technologies, and the adequacy of the current storage research and development program to meet these requirements are among the factors discussed. Emphasis is placed on identification of where the greatest potential exists for energy storage in support of those solar energy systems which could have a significant impact on the U.S. energy mix.

  1. Performance analysis of a soil-based thermal energy storage system using solar-driven air-source heat pump for Danish buildings sector

    DEFF Research Database (Denmark)

    Jradi, M.; Veje, C.; Jørgensen, B. N.

    2017-01-01

    and evaluation of the performance of an underground soil-based thermal energy storage system for solar energy storage, coupled with a combined heat and power generation system. A combined PV-Air Source Heat Pump (ASHP) system is utilized to fulfil heating and electricity needs of a housing project in Odense......Denmark has set an ambitious long-term future energy goal to become independent of fossil fuel by 2050, depending completely on renewable and alternative resources in the energy and transport sectors. Solar energy is one of the most favourable alternative resources in terms of cleanness, safety...... and the economic and environmental aspects. However, the intermittent nature of solar energy and the lack of high solar radiation intensities in various climates favour the use of various energy storage techniques to eliminate the discrepancy between energy supply and demand. The current work presents an analysis...

  2. Superconducting magnetic energy storage, possibilities and limitations

    International Nuclear Information System (INIS)

    Bace, M.; Knapp, V.

    1981-01-01

    Energy storage is of great importance for the exploitation of new energy sources as well as for the better utilisation of conventional ones. Several proposals in recent years have suggested that superconducting magnets could be used as energy storage in large electricity networks. It is a purpose of this note to point out that the requirements which have to be met by energy storage in a large electricity network place serious limitation on the possible use of superconducting energy storage. (author)

  3. Microwavable thermal energy storage material

    Science.gov (United States)

    Salyer, Ival O.

    1998-09-08

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

  4. Real-Time Wavelet-Based Coordinated Control of Hybrid Energy Storage Systems for Denoising and Flattening Wind Power Output

    Directory of Open Access Journals (Sweden)

    Tran Thai Trung

    2014-10-01

    Full Text Available Since the penetration level of wind energy is continuously increasing, the negative impact caused by the fluctuation of wind power output needs to be carefully managed. This paper proposes a novel real-time coordinated control algorithm based on a wavelet transform to mitigate both short-term and long-term fluctuations by using a hybrid energy storage system (HESS. The short-term fluctuation is eliminated by using an electric double-layer capacitor (EDLC, while the wind-HESS system output is kept constant during each 10-min period by a Ni-MH battery (NB. State-of-charge (SOC control strategies for both EDLC and NB are proposed to maintain the SOC level of storage within safe operating limits. A ramp rate limitation (RRL requirement is also considered in the proposed algorithm. The effectiveness of the proposed algorithm has been tested by using real time simulation. The simulation model of the wind-HESS system is developed in the real-time digital simulator (RTDS/RSCAD environment. The proposed algorithm is also implemented as a user defined model of the RSCAD. The simulation results demonstrate that the HESS with the proposed control algorithm can indeed assist in dealing with the variation of wind power generation. Moreover, the proposed method shows better performance in smoothing out the fluctuation and managing the SOC of battery and EDLC than the simple moving average (SMA based method.

  5. Flywheel Energy Storage technology workshop

    Energy Technology Data Exchange (ETDEWEB)

    O`Kain, D.; Howell, D. [comps.

    1993-12-31

    Advances in recent years of high strength/lightweight materials, high performance magnetic bearings, and power electronics technology has spurred a renewed interest by the transportation, utility, and manufacturing industries in Flywheel Energy Storage (FES) technologies. FES offers several advantages over conventional electro-chemical energy storage, such as high specific energy and specific power, fast charging time, long service life, high turnaround efficiency (energy out/energy in), and no hazardous/toxic materials or chemicals are involved. Potential applications of FES units include power supplies for hybrid and electric vehicles, electric vehicle charging stations, space systems, and pulsed power devices. Also, FES units can be used for utility load leveling, uninterruptable power supplies to protect electronic equipment and electrical machinery, and for intermittent wind or photovoltaic energy sources. The purpose of this workshop is to provide a forum to highlight technologies that offer a high potential to increase the performance of FES systems and to discuss potential solutions to overcome present FES application barriers. This document consists of viewgraphs from 27 presentations.

  6. Thermodynamic analysis of a novel tri-generation system based on compressed air energy storage and pneumatic motor

    International Nuclear Information System (INIS)

    Liu, Jin-Long; Wang, Jian-Hua

    2015-01-01

    Based on CAES (compressed air energy storage) and PM (pneumatic motor), a novel tri-generation system (heat energy, mechanical energy and cooling power) is proposed in this paper. Both the cheap electricity generated at night and the excess power from undelivered renewable energy due to instability, can be stored as compressed air and hot water by the proposed system. When energy is in great demand, the compressed air stored in this system is released to drive PM to generate mechanical power. The discharged air from PM can be further utilized as valuable cooling power. Compared to conventional CAES systems, the biggest characteristic of the proposed system is that the discharged air usually abandoned is used as cooling power. In order to study the performances of this system, a thermodynamic analysis and an experimental investigation are carried out. The thermodynamic model is validated by the experimental data. Using the validated thermodynamic model, the mechanical energy output, cooling capacity and temperature of discharged air, as well as the efficiency of the system are analyzed. The theoretical analysis indicates that the additional application of discharged air can improve total energy efficiency by 20–30%. Therefore, this system is very worthy of consideration and being popularized. - Highlights: • The proposed system can provide mechanical energy, heat energy and cooling power. • The exhaust air of pneumatic motor is used as cooling power instead of abandoned. • A thermodynamic model of the proposed system is constructed and validated. • The effects of several parameters on system performance are examined. • The proposed system can improve total energy efficiency of CAES system by 20–30%.

  7. Operations-Based Planning for Placement and Sizing of Energy Storage in a Grid With a High Penetration of Renewables

    OpenAIRE

    Dvijotham, Krishnamurthy; Backhaus, Scott; Chertkov, Misha

    2011-01-01

    As the penetration level of transmission-scale time-intermittent renewable generation resources increases, control of flexible resources will become important to mitigating the fluctuations due to these new renewable resources. Flexible resources may include new or existing synchronous generators as well as new energy storage devices. The addition of energy storage, if needed, should be done optimally to minimize the integration cost of renewable resources, however, optimal placement and sizi...

  8. Energy storage deployment and innovation for the clean energy transition

    Science.gov (United States)

    Kittner, Noah; Lill, Felix; Kammen, Daniel M.

    2017-09-01

    The clean energy transition requires a co-evolution of innovation, investment, and deployment strategies for emerging energy storage technologies. A deeply decarbonized energy system research platform needs materials science advances in battery technology to overcome the intermittency challenges of wind and solar electricity. Simultaneously, policies designed to build market growth and innovation in battery storage may complement cost reductions across a suite of clean energy technologies. Further integration of R&D and deployment of new storage technologies paves a clear route toward cost-effective low-carbon electricity. Here we analyse deployment and innovation using a two-factor model that integrates the value of investment in materials innovation and technology deployment over time from an empirical dataset covering battery storage technology. Complementary advances in battery storage are of utmost importance to decarbonization alongside improvements in renewable electricity sources. We find and chart a viable path to dispatchable US$1 W-1 solar with US$100 kWh-1 battery storage that enables combinations of solar, wind, and storage to compete directly with fossil-based electricity options.

  9. Paper-based energy-storage devices comprising carbon fiber-reinforced polypyrrole-cladophora nanocellulose composite electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Razaq, Aamir; Sjoedin, Martin; Stroemme, Maria; Mihranyan, Albert [Nanotechnology and Functional Materials, Department of Engineering Sciences, Uppsala (Sweden); Department of Chemistry, Angstroem Laboratory, Uppsala (Sweden); Nyholm, Leif [Department of Chemistry, Angstroem Laboratory, Uppsala (Sweden)

    2012-04-15

    Composites of polypyrrole (PPy) and Cladophora nanocellulose, reinforced with 8 {mu}m-thick chopped carbon filaments, can be used as electrode materials to obtain paper-based energy-storage devices with unprecedented performance at high charge and discharge rates. Charge capacities of more than 200 C g{sup -1} (PPy) are obtained for paper-based electrodes at potential scan rates as high as 500 mV s{sup -1}, whereas cell capacitances of {proportional_to}60-70 F g{sup -1} (PPy) are reached for symmetric supercapacitor cells with capacitances up to 3.0 F (i.e.,0.48 F cm{sup -2}) when charged to 0.6 V using current densities as high as 31 A g{sup -1} based on the PPy weight (i.e., 99 mA cm{sup -2}). Energy and power densities of 1.75 Wh kg{sup -1} and 2.7 kW kg{sup -1}, respectively, are obtained when normalized with respect to twice the PPy weight of the smaller electrode. No loss in cell capacitance is seen during charging/discharging at 7.7 A g{sup -1} (PPy) over 1500 cycles. It is proposed that the nonelectroactive carbon filaments decrease the contact resistances and the resistance of the reduced PPy composite. The present straightforward approach represents significant progress in the development of low-cost and environmentally friendly paper-based energy-storage devices for high-power applications. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Electrochemical Energy Storage Technical Team Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-06-01

    This U.S. DRIVE electrochemical energy storage roadmap describes ongoing and planned efforts to develop electrochemical energy storage technologies for plug-in electric vehicles (PEVs). The Energy Storage activity comprises a number of research areas (including advanced materials research, cell level research, battery development, and enabling R&D which includes analysis, testing and other activities) for advanced energy storage technologies (batteries and ultra-capacitors).

  11. The Design of Distributed Micro Grid Energy Storage System

    Science.gov (United States)

    Liang, Ya-feng; Wang, Yan-ping

    2018-03-01

    Distributed micro-grid runs in island mode, the energy storage system is the core to maintain the micro-grid stable operation. For the problems that it is poor to adjust at work and easy to cause the volatility of micro-grid caused by the existing energy storage structure of fixed connection. In this paper, an array type energy storage structure is proposed, and the array type energy storage system structure and working principle are analyzed. Finally, the array type energy storage structure model is established based on MATLAB, the simulation results show that the array type energy storage system has great flexibility, which can maximize the utilization of energy storage system, guarantee the reliable operation of distributed micro-grid and achieve the function of peak clipping and valley filling.

  12. Battery durability and longevity based power management for plug-in hybrid electric vehicle with hybrid energy storage system

    International Nuclear Information System (INIS)

    Zhang, Shuo; Xiong, Rui; Cao, Jiayi

    2016-01-01

    Highlights: • A novel procedure for developing an optimal power management strategy was proposed. • Efficiency and durability were considered to improve the practical performance. • Three control rules were abstracted from the optimization results with DP algorithm. • The proposed control strategy was verified under different SoC and SoH conditions. • The proposed strategy could further improve the energy efficiency obviously. - Abstract: Efficiency and durability are becoming two key issues for the energy storage system in electric vehicles together with their associated power management strategies. In this paper, we present a procedure for the design of a near-optimal power management strategy for the hybrid battery and ultracapacitor energy storage system (HESS) in a plug-in hybrid electric vehicle. The design procedure starts by defining a cost function to minimize the electricity consumption of the HESS and to optimize the operating behavior of the battery. To determine the optimal control actions and power distribution between two power sources, a dynamic programming (DP)-based novel analysis method is proposed, and the optimization framework is presented accordingly. Through analysis of the DP control actions under different battery state-of-health (SoH) conditions, near-optimal rules are extracted. A rule based power management is proposed based on the abstracted rules and simulation results indicate that the new control strategy can improve system efficiency under different SoH and different SoC conditions. Ultimately, the performance of proposed strategy is further verified under different types of driving cycles including the MANHATTAN cycle, 1015 6PRIUS cycle and UDDSHDV cycle.

  13. Graphene hybridization for energy storage applications.

    Science.gov (United States)

    Li, Xianglong; Zhi, Linjie

    2018-03-07

    Graphene has attracted considerable attention due to its unique two-dimensional structure, high electronic mobility, exceptional thermal conductivity, excellent optical transmittance, good mechanical strength, and ultrahigh surface area. To meet the ever increasing demand for portable electronic products, electric vehicles, smart grids, and renewable energy integrations, hybridizing graphene with various functions and components has been demonstrated to be a versatile and powerful strategy to significantly enhance the performance of various energy storage systems such as lithium-ion batteries, supercapacitors and beyond, because such hybridization can result in synergistic effects that combine the best merits of involved components and confer new functions and properties, thereby improving the charge/discharge efficiencies and capabilities, energy/power densities, and cycle life of these energy storage systems. This review will focus on diverse graphene hybridization principles and strategies for energy storage applications, and the proposed outline is as follows. First, graphene and its fundamental properties, followed by graphene hybrids and related hybridization motivation, are introduced. Second, the developed hybridization formulas of using graphene for lithium-ion batteries are systematically categorized from the viewpoint of material structure design, bulk electrode construction, and material/electrode collaborative engineering; the latest representative progress on anodes and cathodes of lithium-ion batteries will be reviewed following such classifications. Third, similar hybridization formulas for graphene-based supercapacitor electrodes will be summarized and discussed as well. Fourth, the recently emerging hybridization formulas for other graphene-based energy storage devices will be briefed in combination with typical examples. Finally, future prospects and directions on the exploration of graphene hybridization toward the design and construction of

  14. Performance analysis of a soil-based thermal energy storage system using solar-driven air-source heat pump for Danish buildings sector

    International Nuclear Information System (INIS)

    Jradi, M.; Veje, C.; Jørgensen, B.N.

    2017-01-01

    Highlights: • PV-driven ASHP system with seasonal underground energy storage is presented. • A soil-based seasonal thermal energy storage unit is analyzed and evaluated. • The system provides heating and electricity for a residential project in Denmark. • The transient behaviour and thermal losses of the thermal storage medium are reported. • The overall heating COP of the PV-driven ASHP combined with seasonal storage is 4.76. - Abstract: Denmark has set an ambitious long-term future energy goal to become independent of fossil fuel by 2050, depending completely on renewable and alternative resources in the energy and transport sectors. Solar energy is one of the most favourable alternative resources in terms of cleanness, safety and the economic and environmental aspects. However, the intermittent nature of solar energy and the lack of high solar radiation intensities in various climates favour the use of various energy storage techniques to eliminate the discrepancy between energy supply and demand. The current work presents an analysis and evaluation of the performance of an underground soil-based thermal energy storage system for solar energy storage, coupled with a combined heat and power generation system. A combined PV-Air Source Heat Pump (ASHP) system is utilized to fulfil heating and electricity needs of a housing project in Odense, Denmark, in addition to charging the soil storage medium in summer months when excess electric power is generated. The stored heat is discharged in December and January to provide the space heating and domestic hot water demands of the residential project without the utilization of an external heating source. Employing a PV system of 30 kW capacity, it was found that a storage medium of 900 m 3 of soil is capable of providing the heating needs for a housing project of 1000 m 2 internal floor area. The year round transient behaviour of the thermal energy storage medium is reported in addition to the heat losses and the

  15. Performance characterization and optimization of microgrid-based energy generation and storage technologies

    Science.gov (United States)

    Guggenberger, Joe David, II

    Renewable energy-powered microgrids have proven to be a valuable technology for self-contained (off-grid) energy systems. Characterizing microgrid system performance pre-deployment would allow the system to be appropriately sized to meet all required electrical loads at a given renewable source operational time frequency. A vanadium redox battery was empirically characterized to determine operating efficiency as a function of charging characteristics and parasitic load losses. A model was developed to iteratively determine system performance based on known weather conditions and load requirements. A case study was performed to compare modeled system performance to measurements taken during operation of the microgrid system. Another iterative model was developed to incrementally predict the microgrid operating performance as a function of diesel generator operating frequency. Calibration of the model was performed to determine accurate PV panel and inverter efficiencies. A case study was performed to estimate the constant loads the system could power at varying diesel generator operating frequencies. Typical Meteorological Year 3 (TMY3) data from 217 Class I locations throughout the United States was inserted into the model to determine the quantity of external AC and DC load the system could supply at intermittent diesel generator variable operational frequencies. Ordinary block Kriging analysis was performed using ArcGIS to interpolate AC and DC load power between TMY3 Class I locations for each diesel generator operating frequency. Figures representing projected AC and DC external load were then developed for each diesel generator operating frequency.

  16. Economics of compressed air energy storage employing thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, S.C.; Reilly, R.W.

    1979-11-01

    The approach taken in this study is to adopt system design and capital cost estimates from three independent CAES studies (eight total designs) and, by supplying a common set of fuel/energy costs and economic assumptions in conjunction with a common methodology, to arrive at a series of levelized energy costs over the system's lifetime. In addition, some analyses are provided to gauge the sensitivity of these levelized energy costs to fuel and compression energy costs and to system capacity factors. The systems chosen for comparison are of four generic types: conventional CAES, hybrid CAES, adiabatic CAES, and an advanced-design gas turbine (GT). In conventional CAES systems the heat of compression generated during the storage operation is rejected to the environment, and later, during the energy-generation phase, turbine fuel must be burned to reheat the compressed air. In the hybrid systems some of the heat of compression is stored and reapplied later during the generation phase, thereby reducing turbine fuel requirements. The adiabatic systems store adequate thermal energy to eliminate the need for turbine fuel entirely. The gas turbine is included within the report for comparison purposes; it is an advanced-design turbine, one that is expected to be available by 1985.

  17. Discharge rate balancing control strategy based on dynamic consensus algorithm for energy storage units in AC microgrids

    DEFF Research Database (Denmark)

    Guan, Yajuan; Meng, Lexuan; Li, Chendan

    2017-01-01

    A dynamic consensus algorithm-based coordinated secondary control with an autonomous current-sharing control strategy is proposed in this paper for balancing discharge rate of energy storage systems (ESSs) in an islanded AC microgrid. The dynamic consensus algorithm is applied for information...... sharing between distributed generation (DG) units in order to regulate the output power of DGs according to ESS capacities and state-of-charge (SoC). The proposed controller can not only effectively prevent operation failure caused by over current and unintentional outage of DGs by means of balanced...... discharge rate control, but also provide fast response and accurate current sharing performance due to an autonomous current-sharing controller at primary level. In addition, expandability, flexibility and high reliability can be obtained thanks to the distributed architecture. Based on the developed...

  18. Energy Management Strategy Based on Multiple Operating States for a Photovoltaic/Fuel Cell/Energy Storage DC Microgrid

    Directory of Open Access Journals (Sweden)

    Ying Han

    2017-01-01

    Full Text Available It is a great challenge for DC microgrids with stochastic renewable sources and volatility loads to achieve better operation performance. This study proposes an energy management strategy based on multiple operating states for a DC microgrid, which is comprised of a photovoltaic (PV array, a proton exchange membrane fuel cell (PEMFC system, and a battery bank. This proposed strategy can share the power properly and keep the bus voltage steady under different operating states (the state of charge (SOC of the battery bank, loading conditions, and PV array output power. In addition, a microgrids test platform is established. In order to verify the effectiveness of the proposed energy management strategy, the strategy is implemented in a hardware system and experimentally tested under different operating states. The experimental results illustrate the good performance of the proposed control strategy for the DC microgrid under different scenarios of power generation and load demand.

  19. Development of high-energy silicon-based anode materials for lithium-ion storage

    Science.gov (United States)

    Yi, Ran

    The emerging markets of electric vehicles (EV) and hybrid electric vehicles (HEV) generate a tremendous demand for low-cost lithium-ion batteries (LIBs) with high energy and power densities, and long cycling life. The development of such LIBs requires development of low cost, high-energy-density cathode and anode materials. Conventional anode materials in commercial LIBs are primarily synthetic graphite-based materials with a capacity of ˜370 mAh/g. Improvements in anode performance, particularly in anode capacity, are essential to achieving high energy densities in LIBs for EV and HEV applications. This dissertation focuses on development of micro-sized silicon-carbon (Si-C) composites as anode materials for high energy and power densities LIBs. First, a new, low-cost, large-scale approach was developed to prepare a micro-sized Si-C composite with excellent performance as an anode material for LIBs. The composite shows a reversible capacity of 1459 mAh/g after 200 cycles at 1 A/g (97.8% capacity retention) and excellent high rate performance of 700 mAh/g at 12.8 A/g, and also has a high tap density of 0.78 g/cm3. The structure of the composite, micro-sized as a whole, features the interconnected nanoscale size of the Si building blocks and the uniform carbon filling, which enables the maximum utilization of silicon even when the micro-sized particles break into small pieces upon cycling. To understand the effects of key parameters in designing the micro-sized Si-C composites on their electrochemical performance and explore how to optimize them, the influence of Si nanoscale building block size and carbon coating on the electrochemical performance of the micro-sized Si-C composites were investigated. It has been found that the critical Si building block size is 15 nm, which enables a high capacity without compromising the cycling stability, and that carbon coating at higher temperature improves the 1st cycle coulombic efficiency (CE) and the rate capability

  20. High energy storage density over a broad temperature range in sodium bismuth titanate-based lead-free ceramics.

    Science.gov (United States)

    Yang, Haibo; Yan, Fei; Lin, Ying; Wang, Tong; Wang, Fen

    2017-08-18

    A series of (1-x)Bi 0.48 La 0.02 Na 0.48 Li 0.02 Ti 0.98 Zr 0.02 O 3 -xNa 0.73 Bi 0.09 NbO 3 ((1-x)LLBNTZ-xNBN) (x = 0-0.14) ceramics were designed and fabricated using the conventional solid-state sintering method. The phase structure, microstructure, dielectric, ferroelectric and energy storage properties of the ceramics were systematically investigated. The results indicate that the addition of Na 0.73 Bi 0.09 NbO 3 (NBN) could decrease the remnant polarization (P r ) and improve the temperature stability of dielectric constant obviously. The working temperature range satisfying TCC 150  °C  ≤±15% of this work spans over 400 °C with the compositions of x ≥ 0.06. The maximum energy storage density can be obtained for the sample with x = 0.10 at room temperature, with an energy storage density of 2.04 J/cm 3 at 178 kV/cm. In addition, the (1-x)LLBNTZ-xNBN ceramics exhibit excellent energy storage properties over a wide temperature range from room temperature to 90 °C. The values of energy storage density and energy storage efficiency is 0.91 J/cm 3 and 79.51%, respectively, for the 0.90LLBNTZ-0.10NBN ceramic at the condition of 100 kV/cm and 90 °C. It can be concluded that the (1-x)LLBNTZ-xNBN ceramics are promising lead-free candidate materials for energy storage devices over a broad temperature range.

  1. Large-Scale Multifunctional Electrochromic-Energy Storage Device Based on Tungsten Trioxide Monohydrate Nanosheets and Prussian White.

    Science.gov (United States)

    Bi, Zhijie; Li, Xiaomin; Chen, Yongbo; He, Xiaoli; Xu, Xiaoke; Gao, Xiangdong

    2017-09-06

    A high-performance electrochromic-energy storage device (EESD) is developed, which successfully realizes the multifunctional combination of electrochromism and energy storage by constructing tungsten trioxide monohydrate (WO 3 ·H 2 O) nanosheets and Prussian white (PW) film as asymmetric electrodes. The EESD presents excellent electrochromic properties of broad optical modulation (61.7%), ultrafast response speed (1.84/1.95 s), and great coloration efficiency (139.4 cm 2 C -1 ). In particular, remarkable cyclic stability (sustaining 82.5% of its initial optical modulation after 2500 cycles as an electrochromic device, almost fully maintaining its capacitance after 1000 cycles as an energy storage device) is achieved. The EESD is also able to visually detect the energy storage level via reversible and fast color changes. Moreover, the EESD can be combined with commercial solar cells to constitute an intelligent operating system in the architectures, which would realize the adjustment of indoor sunlight and the improvement of physical comfort totally by the rational utilization of solar energy without additional electricity. Besides, a scaled-up EESD (10 × 11 cm 2 ) is further fabricated as a prototype. Such promising EESD shows huge potential in practically serving as electrochromic smart windows and energy storage devices.

  2. Thermal energy storage and transport

    Science.gov (United States)

    Hausz, W.

    1980-01-01

    The extraction of thermal energy from large LWR and coal fired plants for long distance transport to industrial and residential/commercial users is analyzed. Transport of thermal energy as high temperature water is shown to be considerably cheaper than transport as steam, hot oil, or molten salt over a wide temperature range. The delivered heat is competitive with user-generated heat from oil, coal, or electrode boilers at distances well over 50 km when the pipeline operates at high capacity factor. Results indicate that thermal energy storage makes meeting of even very low capacity factor heat demands economic and feasible and gives the utility flexibility to meet coincident electricity and heat demands effectively.

  3. Analysis of recovery efficiency in high-temperature aquifer thermal energy storage : a Rayleigh-based method

    NARCIS (Netherlands)

    Schout, Gilian; Drijver, Benno; Gutierrez-Neri, Mariene; Schotting, Ruud

    High-temperature aquifer thermal energy storage (HT-ATES) is an important technique for energy conservation. A controlling factor for the economic feasibility of HT-ATES is the recovery efficiency. Due to the effects of density-driven flow (free convection), HTATES systems applied in permeable

  4. Energy Proportionality for Disk Storage Using Replication

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinoh; Rotem, Doron

    2010-09-09

    Energy saving has become a crucial concern in datacenters as several reports predict that the anticipated energy costs over a three year period will exceed hardware acquisition. In particular, saving energy for storage is of major importance as storage devices (and cooling them off) may contribute over 25 percent of the total energy consumed in a datacenter. Recent work introduced the concept of energy proportionality and argued that it is a more relevant metric than just energy saving as it takes into account the tradeoff between energy consumption and performance. In this paper, we present a novel approach, called FREP (Fractional Replication for Energy Proportionality), for energy management in large datacenters. FREP includes areplication strategy and basic functions to enable flexible energy management. Specifically, our method provides performance guarantees by adaptively controlling the power states of a group of disks based on observed and predicted workloads. Our experiments, using a set of real and synthetic traces, show that FREP dramatically reduces energy requirements with a minimal response time penalty.

  5. Electricity storage - A challenge for energy transition

    International Nuclear Information System (INIS)

    Bart, Jean-Baptiste; Nekrasov, Andre; Pastor, Emmanuel; Benefice, Emmanuel; Brincourt, Thierry; Cagnac, Albannie; Brisse, Annabelle; Jeandel, Elodie; Lefebvre, Thierry; Penneau, Jean-Francois; Radvanyi, Etienne; Delille, Gautier; Hinchliffe, Timothee; Lancel, Gilles; Loevenbruck, Philippe; Soler, Robert; Stevens, Philippe; Torcheux, Laurent

    2017-01-01

    After a presentation of the energetic context and of its issues, this collective publication proposes presentations of various electricity storage technologies with a distinction between direct storage, thermal storage and hydrogen storage. As far as direct storage is concerned, the following options are described: pumped energy transfer stations or PETS, compressed air energy storage or CAES, flywheels, various types of electrochemical batteries (lead, alkaline, sodium, lithium), metal air batteries, redox flow batteries, and super-capacitors. Thermal storage comprises power-to-heat and heat-to-power technologies. Hydrogen can be stored under different forms (compressed gas, liquid), in saline underground cavities, or by using water electrolysis and fuel cells. The authors propose an overview of the different services provided by energy storage to the electricity system, and discuss the main perspectives and challenges for tomorrow's storage (electric mobility, integration of renewable energies, electrification of isolated areas, scenarios of development)

  6. Integration of Energy Storage in Distribution Grids

    OpenAIRE

    Geth, Frederik; Tant, Jeroen; Haesen, Edwin; Driesen, Johan; Belmans, Ronnie

    2010-01-01

    Electrical energy storage services can bring benefit to multiple stakeholders in the distribution grid. Energy storage owners maximize their profit on an external energy market. This can cause a conflict with the distribution system operator because a grid is designed in terms of peak power, not energy. The subject of this paper is a optimization method for the siting and sizing of energy storage in distribution grids. The optimization is implemented multi-objective as to visualize the trade-...

  7. Evaluation of three energy balance-based evaporation models for estimating monthly evaporation for five lakes using derived heat storage changes from a hysteresis model

    NARCIS (Netherlands)

    Duan, Z.; Bastiaanssen, W.G.M.

    2017-01-01

    The heat storage changes (Qt) can be a significant component of the energy balance in lakes, and it is important to account for Qt for reasonable estimation of evaporation at monthly and finer timescales if the energy balance-based evaporation models are used. However, Qt has been often neglected in

  8. Seasonal sensible thermal energy storage solutions

    Directory of Open Access Journals (Sweden)

    Lavinia Gabriela SOCACIU

    2012-08-01

    Full Text Available The thermal energy storage can be defined as the temporary storage of thermal energy at high or low temperatures. Thermal energy storage is an advances technology for storing thermal energy that can mitigate environmental impacts and facilitate more efficient and clean energy systems. Seasonal thermal energy storage has a longer thermal storage period, generally three or more months. This can contribute significantly to meeting society`s need for heating and cooling. The objectives of thermal energy storage systems are to store solar heat collected in summer for space heating in winter. This concept is not new; it is been used and developed for centuries because is playing an important role in energy conservation and contribute significantly to improving the energy efficiency and reducing the gas emissions to the atmosphere.

  9. Improving wind power quality with energy storage

    DEFF Research Database (Denmark)

    Rasmussen, Claus Nygaard

    2009-01-01

    The results of simulation of the influence of energy storage on wind power quality are presented. Simulations are done using a mathematical model of energy storage. Results show the relation between storage power and energy, and the obtained increase in minimum available power from the combination...... of wind and storage. The introduction of storage enables smoothening of wind power on a timescale proportional to the storage energy. Storage does not provide availability of wind power at all times, but allows for a certain fraction of average power in a given timeframe to be available with high...... probability. The amount of storage capacity necessary for significant wind power quality improvement in a given period is found to be 20 to 40% of the energy produced in that period. The necessary power is found to be 80 to 100% of the average power of the period....

  10. Optimal fuzzy logic-based PID controller for load-frequency control including superconducting magnetic energy storage units

    International Nuclear Information System (INIS)

    Pothiya, Saravuth; Ngamroo, Issarachai

    2008-01-01

    This paper proposes a new optimal fuzzy logic-based-proportional-integral-derivative (FLPID) controller for load frequency control (LFC) including superconducting magnetic energy storage (SMES) units. Conventionally, the membership functions and control rules of fuzzy logic control are obtained by trial and error method or experiences of designers. To overcome this problem, the multiple tabu search (MTS) algorithm is applied to simultaneously tune PID gains, membership functions and control rules of FLPID controller to minimize frequency deviations of the system against load disturbances. The MTS algorithm introduces additional techniques for improvement of search process such as initialization, adaptive search, multiple searches, crossover and restarting process. Simulation results explicitly show that the performance of the optimum FLPID controller is superior to the conventional PID controller and the non-optimum FLPID controller in terms of the overshoot, settling time and robustness against variations of system parameters

  11. Multi-Agent-Based Distributed State of Charge Balancing Control for Distributed Energy Storage Units in AC Microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Dragicevic, Tomislav; Vasquez, Juan Carlos

    2015-01-01

    In this paper, a multiagent based distributed control algorithm has been proposed to achieve state of charge (SoC) balance of distributed energy storage (DES) units in an AC microgrid. The proposal uses frequency scheduling instead of adaptive droop gain. Each DES unit is taken as an agent...... and they schedule their own frequency reference given of the real power droop controller according to the SoC values of the other DES units. Further, to obtain the average SoC value of DES, dynamic average consensus algorithm is adapted by each agent. A smallsignal model of the system is developed in order...... to verify the stability of the control system and control parameters design. Simulation results demonstrate the effectiveness of the control strategy and also show the robustness against communication topology changes....

  12. Control strategy of wind turbine based on permanent magnet synchronous generator and energy storage for stand-alone systems

    DEFF Research Database (Denmark)

    Deng, Fujin; Liu, Dong; Chen, Zhe

    2017-01-01

    This paper investigates a variable speed wind turbine based on permanent magnet synchronous generator and a full-scale power converter in a stand-alone system. An energy storage system(ESS) including battery and fuel cell-electrolyzer combination is connected to the DC link of the full-scale power...... converter through the power electronics interface. Wind is the primary power source of the system, the battery and FC-electrolyzer combination is used as a backup and a long-term storage system to provide or absorb power in the stand-alone system, respectively. In this paper, a control strategy is proposed...... for the operation of this variable speed wind turbine in a stand-alone system, where the generator-side converter and the ESS operate together to meet the demand of the loads. This control strategy is competent for supporting the variation of the loads or wind speed and limiting the DC-link voltage of the full...

  13. Panorama 2013 - Mass storage of energy

    International Nuclear Information System (INIS)

    Ponsot-Jacquin, Catherine; Bertrand, Jean-Fabrice

    2012-10-01

    It is universally apparent that environmental and energy transition must evolve in order to meet the needs of a growing world population while still heeding environmental constraints. This change over time will be based on a sustainable energy mix, and consequently the use of renewable energy sources is likely to intensify over the coming decades in respond to rising demand for electricity worldwide. The International Energy Agency (IEA) predicts that 40% of electricity will come from renewable sources by 2050. Some of these renewable forms of energy generate power on an irregular and intermittent basis, and energy storage offers one solution for deploying these intermittent energy sources more widely as part of an efficient smart grid. (authors)

  14. Recent Advances on Porous Carbon Materials for Electrochemical Energy Storage.

    Science.gov (United States)

    Wang, Libin; Hu, Xianluo

    2018-04-17

    The climate change and energy crisis promote the rapid development of electrochemical energy-storage devices. Of many intriguing physicochemical properties such as excellent chemical stability, high electronic conductivity and large specific surface area, porous carbon materials have always been considering as a promising candidate for electrochemical energy storage. Up to date, a wide variety of porous carbon materials upon molecular design, pore control and compositional tailoring have been proposed for energy-storage applications. This focus review summaries recent advances in the synthesis of various porous carbon materials from the view of energy storage, especially in the past three years. Their applications in representative electrochemical energy storage devices like lithium-ion batteries, supercapacitors, lithium-ion hybrid capacitors have been discussed in this review, looking forward to offering some inspirations and guidelines for the exploitation of advanced carbon-based energy-storage materials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Dynamic modeling of a solar receiver/thermal energy storage system based on a compartmented dense gas fluidized bed

    Science.gov (United States)

    Solimene, Roberto; Chirone, Roberto; Chirone, Riccardo; Salatino, Piero

    2017-06-01

    Fluidized beds may be considered a promising option to collection and storage of thermal energy of solar radiation in Concentrated Solar Power (CSP) systems thanks to their excellent thermal properties in terms of bed-to-wall heat transfer coefficient and thermal diffusivity and to the possibility to operate at much higher temperature. A novel concept of solar receiver for combined heat and power (CHP) generation consisting of a compartmented dense gas fluidized bed has been proposed to effectively accomplish three complementary tasks: collection of incident solar radiation, heat transfer to the working fluid of the thermodynamic cycle and thermal energy storage. A dynamical model of the system laid the basis for optimizing collection of incident radiative power, heat transfer to the steam cycle, storage of energy as sensible heat of bed solids providing the ground for the basic design of a 700kWth demonstration CSP plant.

  16. Energy Management System Based on Fuzzy fractional order PID Controller for Transient Stability Improvement in Microgrids with Energy Storage

    DEFF Research Database (Denmark)

    Moafi, Milad; Marzband, Mousa; Savaghebi, Mehdi

    2016-01-01

    in the islanded Microgrid (MG). To increase performance for a wide range of power system operating conditions, an energy management systems (EMS) is proposed based on a fuzzy fractional order PID (FFOPID) controller. It is able to analyze and simulate the dynamic behavior in grid connected MGs. This controller...... combined with a PID-controller (termed as FLPID) and Fuzzy fractional order PID (termed as FFOPID) are implemented according to the characteristics and limitations of overloading and state of charge (SOC). The obtained results show good performance of FFOPID controllers by improving the transient stability...... following a fault that has caused the islanded operation. Simulation results have validated the effectiveness of FFOPID controllers in the system under several scenarios with superior stabilization and more robustness in comparison with the FLPID and PID controller....

  17. Lowering the cost of large-scale energy storage: High temperature adiabatic compressed air energy storage

    Directory of Open Access Journals (Sweden)

    B. Cárdenas

    2017-06-01

    Full Text Available Compressed air energy storage is an energy storage technology with strong potential to play a significant role in balancing energy on transmission networks, owing to its use of mature technologies and low cost per unit of storage capacity. Adiabatic compressed air energy storage (A-CAES systems typically compress air from ambient temperature in the charge phase and expand the air back to ambient temperature in the discharge phase. This papers explores the use of an innovative operating scheme for an A-CAES system aimed at lowering the total cost of the system for a given exergy storage capacity. The configuration proposed considers preheating of the air before compression which increases the fraction of the total exergy that is stored in the form of high-grade heat in comparison to existing designs in which the main exergy storage medium is the compressed air itself. Storing a high fraction of the total exergy as heat allows reducing the capacity of costly pressure stores in the system and replacing it with cheaper thermal energy stores. Additionally, a configuration that integrates a system based on the aforementioned concept with solar thermal power or low-medium grade waste heat is introduced and thoroughly discussed.

  18. Electric energy storage - Overview of technologies

    International Nuclear Information System (INIS)

    Boye, Henri

    2013-01-01

    Energy storage is a challenging and costly process, as electricity can only be stored by conversion into other forms of energy (e.g. potential, thermal, chemical or magnetic energy). The grids must be precisely balanced in real time and it must be made sure that the cost of electricity is the lowest possible. Storage of electricity has many advantages, in centralized mass storages used for the management of the transmission network, or in decentralized storages of smaller dimensions. This article presents an overview of the storage technologies: mechanical storage in hydroelectric and pumped storage power stations, compressed air energy storage (CAES), flywheels accumulating kinetic energy, electrochemical batteries with various technologies, traditional lead acid batteries, lithium ion, sodium sulfur (NaS) and others, including vehicle to grid, sensible heat thermal storage, superconducting magnetic energy storage (SMES), super-capacitors, conversion into hydrogen... The different technologies are compared in terms of cost and level of maturity. The development of intermittent renewable energies will result in a growing need for mechanisms to regulate energy flow and innovative energy storage solutions seem well positioned to develop. (author)

  19. A New Modular Multilevel Converter with Integrated Energy Storage

    DEFF Research Database (Denmark)

    Trintis, Ionut; Munk-Nielsen, Stig; Teodorescu, Remus

    2011-01-01

    This paper introduces a new modular converter with integrated energy storage based on the cascaded half-bridge modular multilevel converter with common DC bus. It represents a complete modular solution with power electronics and energy storage building blocks, for medium and high voltage...... in the future HVDC meshed grids. Its functionality and flexibility makes the converter independent on the energy storage unit characteristic. The converter concept with its basic functions and control schemes are described and evaluated in this paper....

  20. Energy Storage System Scheduling in Wind-Diesel Microgrids

    Science.gov (United States)

    Ross, Michael

    This thesis proposes a knowledge based expert system tool that can be used as an online controller for the charging/discharging of an energy storage system in a wind-diesel microgrid. The wind-diesel microgrid is modelled, and a typical energy storage system is implemented to test the functionality of the controller using hourly-discrete power values. The results are compared against an offline optimization that was provided 24-hour lookahead wind values, as well as a controller that was implemented using artificial neural networks. The knowledge based expert system is then used to analyze the cost of energy, by means of a parametric analysis, consisting of varying the wind penetration, energy storage system power rating and energy rating to determine for which wind penetration values a storage system implementation would be technically and economically viable. Different storage technologies are tested in a one-year time frame to determine which would be best suited for this particular application. The energy storage systems are implemented as single-layer and dual-layer, in which the knowledge based expert system is modified for the latter analysis, in order to determine whether or not there are advantages to having a dual-layer storage system. Throughout these analyses, the flexibility of the knowledge based expert system controller to various energy storage systems and microgrid models is verified. It also demonstrates that, in a context of high base generation costs, energy storage can be a viable solution to managing wind power variations.

  1. Easy and industrially applicable impregnation process for preparation of diatomite-based phase change material nanocomposites for thermal energy storage

    International Nuclear Information System (INIS)

    Konuklu, Yeliz; Ersoy, Orkun; Gokce, Ozgur

    2015-01-01

    The high porosity, high oil and water absorption capacity and low density of diatomite make it ideal for industrial applications. The porous structure of diatomite protects phase change materials (PCMs) from environmental factors as a supporting matrix and phase changes occur in nanopores of diatomite. Previous research on diatomite/PCMs composites aimed optimal composite preparation but many methods were feasible only in laboratory scale. In large scale industrial fabrication, easy, continuous and steady state methods are need to be performed. The main purpose of this study was to prepare leakage-free, thermally stable nanocomposite PCMs (nanoCPCMs) by an easy, continuous and steady state method for high temperature thermal energy storage applications. A series of nanoCPCMs with different paraffin:diatomite mass ratios were prepared. The properties of nanoCPCMs have been characterized via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The leak (exudation) test was performed on prepared composites at higher temperatures (95 °C) in comparison with literature. As the optimum composite for thermal energy storage applications, thermal reliability of nanoCPCM was evaluated after 400 cycles of melting and freezing. NanoCPCM melted at 36.55 °C with latent heat of 53.1 J/g. - Highlights: • Diatomite-based phase change material nanocomposites were prepared. • An easy and industrially applicable impregnation process was developed. • Influence of diatomite: PCM mass ratio on thermal properties reported.

  2. Fault-Tolerant Control for a Flexible Group Battery Energy Storage System Based on Cascaded Multilevel Converters

    Directory of Open Access Journals (Sweden)

    Junhong Song

    2018-01-01

    Full Text Available A flexible group battery energy storage system (FGBESS based on cascaded multilevel converters is attractive for renewable power generation applications because of its high modularity and high power quality. However, reliability is one of the most important issues and the system may suffer from great financial loss after fault occurs. In this paper, based on conventional fundamental phase shift compensation and third harmonic injection, a hybrid compensation fault-tolerant method is proposed to improve the post-fault performance in the FGBESS. By adjusting initial phase offset and amplitude of injected component, the optimal third harmonic injection is generated in an asymmetric system under each faulty operation. Meanwhile, the optimal redundancy solution under each fault condition is also elaborated comprehensively with a comparison of the presented three fault-tolerant strategies. This takes full advantage of battery utilization and minimizes the loss of energy capacity. Finally, the effectiveness and feasibility of the proposed methods are verified by results obtained from simulations and a 10 kW experimental platform.

  3. Targeting adequate thermal stability and fire safety in selecting ionic liquid-based electrolytes for energy storage.

    Science.gov (United States)

    Chancelier, L; Diallo, A O; Santini, C C; Marlair, G; Gutel, T; Mailley, S; Len, C

    2014-02-07

    The energy storage market relating to lithium based systems regularly grows in size and expands in terms of a portfolio of energy and power demanding applications. Thus safety focused research must more than ever accompany related technological breakthroughs regarding performance of cells, resulting in intensive research on the chemistry and materials science to design more reliable batteries. Formulating electrolyte solutions with nonvolatile and hardly flammable ionic liquids instead of actual carbonate mixtures could be safer. However, few definitions of thermal stability of electrolytes based on ionic liquids have been reported in the case of abuse conditions (fire, shortcut, overcharge or overdischarge). This work investigates thermal stability up to combustion of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C1C4Im][NTf2]) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([PYR14][NTf2]) ionic liquids, and their corresponding electrolytes containing lithium bis(trifluoromethanesulfonyl)imide LiNTf2. Their possible routes of degradation during thermal abuse testings were investigated by thermodynamic studies under several experimental conditions. Their behaviours under fire were also tested, including the analysis of emitted compounds.

  4. Hybrid Hydro Renewable Energy Storage Model

    Science.gov (United States)

    Dey, Asit Kr

    2018-01-01

    This paper aims at presenting wind & tidal turbine pumped-storage solutions for improving the energy efficiency and economic sustainability of renewable energy systems. Indicated a viable option to solve problems of energy production, as well as in the integration of intermittent renewable energies, providing system flexibility due to energy load’s fluctuation, as long as the storage of energy from intermittent sources. Sea water storage energy is one of the best and most efficient options in terms of renewable resources as an integrated solution allowing the improvement of the energy system elasticity and the global system efficiency.

  5. Energy storage: a review of recent literature

    International Nuclear Information System (INIS)

    Tatone, O.S.

    1981-12-01

    Recent literature on the technological and economic status of reversible energy storage has been reviewed. A broad range of research and development activities have been pursued between 1975 and the present. Most of this work has concentrated on improving technical and economic performance of previously known storage technologies. Hydraulic pumped storage with both reservoirs above ground and compressed air storage (1 plant) are the only methods that have been adopted by electric utilities. The need for electrical energy storage in Canada has not been acute because of the large proportion of hydraulic generation which incorporates some storge and, in most cases, can readily be used for load-following. Residential heat storage in ceramic room heaters has been used in Europe for several years. For Canadian climatic and market conditions larger, central heating units would be required. Residential heat storage depends upon utilities offering time-of-use rates and none in Canada do so at present. Most seasonal storage concepts depend upon storage of low-grade heat for district heating. The cost of energy storage is highly dependent upon annual energy throughput and hence favours smaller capacity systems operating on frequent charge/discharge cycles over long-term storage. Capital costs of energy storage methods from the literature, expressed in constant dollars, are compared graphically and tentative investment costs are presented for several storage methods

  6. Kinetic Storage as an Energy Management System

    International Nuclear Information System (INIS)

    Garcia-Tabares, L.

    2007-01-01

    The possibility of storing energy is increasingly important and necessary. The reason is that storage modifies the basic equation of the energy production balance which states that the power produced should equal the power consumed. When there is a storage device in the grid, this equation is modified such that, in the new balance, the energy produced should equal the algebraic sum of the energy consumed and the energy stored (positive in storage phase and negative when released). This means that the generation profile can be uncoupled from the consumption profile, with the resulting improvement of efficiency. Even small-sized storage systems can be very effective. (Author) 10 refs

  7. Battery storage for supplementing renewable energy systems

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-01-18

    The battery storage for renewable energy systems section of the Renewable Energy Technology Characterizations describes structures and models to support the technical and economic status of emerging renewable energy options for electricity supply.

  8. A silicone rubber based composites using n-octadecane/poly (styrene-methyl methacrylate) microcapsules as energy storage particle

    Science.gov (United States)

    Wu, W. L.; Chen, Z.

    A phase-change energy-storage material, silicone rubber (SR) coated n-octadecane/poly (styrene-methyl methacrylate) (SR/OD/P(St-MMA)) microcapsule composites, was prepared by mixing SR and OD/P(St-MMA) microcapsules. The microcapsule content and silicone rubber coated method were investigated. The morphology and thermal properties of the composites were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TG), differential scanning calorimetry (DSC) and heat storage properties. The results showed that the thermal and mechanical properties of SR/OD/P(St-MMA) composites were excellent when the microcapsules were coated with room temperature vulcanized silicone rubber (RTVSR), of which content was 2 phr (per hundred rubber). The enthalpy value of the composites was 67.6 J g-1 and the composites were found to have good energy storage function.

  9. Electric utility applications of hydrogen energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Swaminathan, S.; Sen, R.K.

    1997-10-15

    This report examines the capital cost associated with various energy storage systems that have been installed for electric utility application. The storage systems considered in this study are Battery Energy Storage (BES), Superconducting Magnetic Energy Storage (SMES) and Flywheel Energy Storage (FES). The report also projects the cost reductions that may be anticipated as these technologies come down the learning curve. This data will serve as a base-line for comparing the cost-effectiveness of hydrogen energy storage (HES) systems in the electric utility sector. Since pumped hydro or compressed air energy storage (CAES) is not particularly suitable for distributed storage, they are not considered in this report. There are no comparable HES systems in existence in the electric utility sector. However, there are numerous studies that have assessed the current and projected cost of hydrogen energy storage system. This report uses such data to compare the cost of HES systems with that of other storage systems in order to draw some conclusions as to the applications and the cost-effectiveness of hydrogen as a electricity storage alternative.

  10. Multi-Agent-Based Controller for Voltage Enhancement in AC/DC Hybrid Microgrid Using Energy Storages

    OpenAIRE

    Ahmadali Khatibzadeh; Mohammadreza Besmi; Aminollah Mahabadi; Mahmoud Reza Haghifam

    2017-01-01

    Development of renewable energies and DC loads have led microgrids toward the creation of DC networks. The predictions show that the hybrid microgrids will be used widely in the future. This article has studied the voltage stability in the presence of sources of energy storage in AC/DC hybrid networks. However, because the different dynamics of hybrid networks applying centralized and distributed controllers will be faced with different problems, in this study, a multi-agent control for the m...

  11. Proceedings of the DOE chemical energy storage and hydrogen energy systems contracts review

    Energy Technology Data Exchange (ETDEWEB)

    1980-02-01

    Sessions were held on electrolysis-based hydrogen storage systems, hydrogen production, hydrogen storage systems, hydrogen storage materials, end-use applications and system studies, chemical heat pump/chemical energy storage systems, systems studies and assessment, thermochemical hydrogen production cycles, advanced production concepts, and containment materials. (LHK)

  12. Fuzzy Logic-Based Operation of Battery Energy Storage Systems (BESSs for Enhancing the Resiliency of Hybrid Microgrids

    Directory of Open Access Journals (Sweden)

    Akhtar Hussain

    2017-02-01

    Full Text Available The resiliency of power systems can be enhanced during emergency situations by using microgrids, due to their capability to supply local loads. However, precise prediction of disturbance events is very difficult rather the occurrence probability can be expressed as, high, medium, or low, etc. Therefore, a fuzzy logic-based battery energy storage system (BESS operation controller is proposed in this study. In addition to BESS state-of-charge and market price signals, event occurrence probability is taken as crisp input for the BESS operation controller. After assessing the membership levels of all the three inputs, BESS operation controller decides the operation mode (subservient or resilient of BESS units. In subservient mode, BESS is fully controlled by an energy management system (EMS while in the case of resilient mode, the EMS follows the commands of the BESS operation controller for scheduling BESS units. Therefore, the proposed hybrid microgrid model can operate in normal, resilient, and emergency modes with the respective objective functions and scheduling horizons. Due to the consideration of resilient mode, load curtailment can be reduced during emergency operation periods. Numerical simulations have demonstrated the effectiveness of the proposed strategy for enhancing the resiliency of hybrid microgrids.

  13. Optimal Scheduling of Energy Storage System for Self-Sustainable Base Station Operation Considering Battery Wear-Out Cost

    Directory of Open Access Journals (Sweden)

    Yohwan Choi

    2016-06-01

    Full Text Available A self-sustainable base station (BS where renewable resources and energy storage system (ESS are interoperably utilized as power sources is a promising approach to save energy and operational cost in communication networks. However, high battery price and low utilization of ESS intended for uninterruptible power supply (UPS necessitates active utilization of ESS. This paper proposes a multi-functional framework of ESS using dynamic programming (DP for realizing a sustainable BS. We develop an optimal charging and discharging scheduling algorithm considering a detailed battery wear-out model to minimize operational cost as well as to prolong battery lifetime. Our approach significantly reduces total cost compared to the conventional method that does not consider battery wear-out. Extensive experiments for several scenarios exhibit that total cost is reduced by up to 70.6% while battery wear-out is also reduced by 53.6%. The virtue of the proposed framework is its wide applicability beyond sustainable BS and thus can be also used for other types of load in principle.

  14. Thermal energy storage for cogeneration applications

    Energy Technology Data Exchange (ETDEWEB)

    Drost, M.K.; Antoniak, Z.I.

    1992-04-01

    Cogeneration is playing an increasingly important role in providing energy efficient power generation and thermal energy for space heating and industrial process heat applications. However, the range of applications for cogeneration could be further increased if the generation of electricity could be coupled from the generation of process heat. Thermal energy storage (TES) can decouple power generation from the production of process heat, allowing the production of dispatchable power while fully utilizing the thermal energy available from the prime mover. The Pacific Northwest Laboratory (PNL) leads the US Department of Energy`s Thermal Energy Storage Program. The program focuses on developing TES for daily cycling (diurnal storage), annual cycling (seasonal storage), and utility applications (utility thermal energy storage (UTES)). Several of these technologies can be used in a cogeneration facility. This paper discusses TES concepts relevant to cogeneration and describes the current status of these TES systems.

  15. Improving wind power quality with energy storage

    DEFF Research Database (Denmark)

    Rasmussen, Claus Nygaard

    2009-01-01

    The results of simulation of the influence of energy storage on wind power quality are presented. Simulations are done using a mathematical model of energy storage. Results show the relation between storage power and energy, and the obtained increase in minimum available power from the combination...... probability. The amount of storage capacity necessary for significant wind power quality improvement in a given period is found to be 20 to 40% of the energy produced in that period. The necessary power is found to be 80 to 100% of the average power of the period....

  16. A silicone rubber based composites using n-octadecane/poly (styrene-methyl methacrylate microcapsules as energy storage particle

    Directory of Open Access Journals (Sweden)

    W.L. Wu

    Full Text Available A phase-change energy-storage material, silicone rubber (SR coated n-octadecane/poly (styrene-methyl methacrylate (SR/OD/P(St-MMA microcapsule composites, was prepared by mixing SR and OD/P(St-MMA microcapsules. The microcapsule content and silicone rubber coated method were investigated. The morphology and thermal properties of the composites were characterized by scanning electron microscopy (SEM, thermogravimetric analysis (TG, differential scanning calorimetry (DSC and heat storage properties. The results showed that the thermal and mechanical properties of SR/OD/P(St-MMA composites were excellent when the microcapsules were coated with room temperature vulcanized silicone rubber (RTVSR, of which content was 2 phr (per hundred rubber. The enthalpy value of the composites was 67.6 J g−1 and the composites were found to have good energy storage function. Keywords: n-Octadecane, Silicone rubber, Microcapsule, Energy-storage, Composites

  17. Battery energy storage market feasibility study -- Expanded report

    Energy Technology Data Exchange (ETDEWEB)

    Kraft, S. [Frost and Sullivan, Mountain View, CA (United States); Akhil, A. [Sandia National Labs., Albuquerque, NM (United States). Energy Storage Systems Analysis and Development Dept.

    1997-09-01

    Under the sponsorship of the US Department of Energy`s Office of Utility Technologies, the Energy Storage Systems Analysis and Development Department at Sandia National Laboratories (SNL) contracted Frost and Sullivan to conduct a market feasibility study of energy storage systems. The study was designed specifically to quantify the battery energy storage market for utility applications. This study was based on the SNL Opportunities Analysis performed earlier. Many of the groups surveyed, which included electricity providers, battery energy storage vendors, regulators, consultants, and technology advocates, viewed battery storage as an important technology to enable increased use of renewable energy and as a means to solve power quality and asset utilization issues. There are two versions of the document available, an expanded version (approximately 200 pages, SAND97-1275/2) and a short version (approximately 25 pages, SAND97-1275/1).

  18. Efficient synthesis of tungsten oxide hydrate-based nanocomposites for applications in bifunctional electrochromic-energy storage devices

    Science.gov (United States)

    Chang, Xueting; Hu, Ruirui; Sun, Shibin; Lu, Tong; Liu, Tao; Lei, Yanhua; Dong, Lihua; Yin, Yansheng; Zhu, Yanqiu

    2018-05-01

    In this work, we realized the large-scale synthesis of WO3 · H2O nanoflakes (NFs), g-C3N4/WO3 · H2O nanocomposite (NC) and graphene (G)/WO3 · H2O NC via a sonochemical process with tungsten salt as the precursor, g-C3N4 or G sheets as the supports, and distilled water as the solvent. Both the g-C3N4/WO3 · H2O NC and G/WO3 · H2O NC exhibited much better electrochromic (EC) performance (higher coloration efficiencies and faster response times) than that of the WO3 · H2O NFs. Using the WO3 · H2O-based materials as electrode materials, EC batteries that integrate the energy storage and EC functions in one device have been assembled. The energy status of the EC batteries could be visually indicated by the reversible color variations. Compared with the plain WO3 · H2O-based EC batteries, the NC-based EC batteries possessed a lower color contrast between the charged and discharged conditions but much longer discharge durations. The EC batteries could be quickly charged in a few seconds by adding H2O2, and the charged batteries exhibited significantly-enhanced discharging durations in comparison with the initial ones. The g-C3N4/WO3 · H2O NC-EC batteries charged by a small amount of H2O2 could produce a long discharging duration up to 760 min.

  19. Bidding strategy for an energy storage facility

    DEFF Research Database (Denmark)

    Nasrolahpour, Ehsan; Zareipour, Hamidreza; Rosehart, William D.

    2016-01-01

    This paper studies operation decisions of energy storage facilities in perfectly and imperfectly competitive markets. In a perfectly competitive market, the storage facility is operated to maximize the social welfare. However, in a imperfectly competitive market, the storage facility operates to ...

  20. Energy storage in Canada - Embassy report

    International Nuclear Information System (INIS)

    Quennehen, Sylvain

    2014-09-01

    After having outlined what is at stake in energy storage in the world (brief presentation of storage methods, overview of world electricity production and its storage challenges), and given an overview of the Canadian energy sector, this report gives an overview of the Canadian key and particularly innovating actors: main organisations, scientific research (in the fields of advanced batteries, of fuel cells, and of thermal storage), industrial sector (leaders in electricity production, in the electric or hybrid automotive sector and in the field of portable electronic devices, in the Li-ion battery sector, and in the hydrogen fuel cell sector, innovating actors in other energy storage methods). The author then discusses the innovation momentum in Canada: examples of energy storage projects by public organisations (CNRC, RNC), industrial projects in energy projects, investment dynamics

  1. Thermal energy storage for cogeneration applications

    Energy Technology Data Exchange (ETDEWEB)

    Drost, M.K.; Antoniak, Z.I.

    1992-04-01

    Cogeneration is playing an increasingly important role in providing energy efficient power generation and thermal energy for space heating and industrial process heat applications. However, the range of applications for cogeneration could be further increased if the generation of electricity could be coupled from the generation of process heat. Thermal energy storage (TES) can decouple power generation from the production of process heat, allowing the production of dispatchable power while fully utilizing the thermal energy available from the prime mover. The Pacific Northwest Laboratory (PNL) leads the US Department of Energy's Thermal Energy Storage Program. The program focuses on developing TES for daily cycling (diurnal storage), annual cycling (seasonal storage), and utility applications (utility thermal energy storage (UTES)). Several of these technologies can be used in a cogeneration facility. This paper discusses TES concepts relevant to cogeneration and describes the current status of these TES systems.

  2. Value assessment of hydrogen-based electrical energy storage in view of electricity spot market

    DEFF Research Database (Denmark)

    You, Shi; Hu, Junjie; Zong, Yi

    2016-01-01

    electricity spot market that has high price volatility due to its high share of wind power. An economic dispatch model is developed as a mixed-integer programming (MIP) problem to support the estimation of variable cost of such a system taking into account a good granularity of the technical details. Based...

  3. A Fuzzy-Logic Power Management Strategy Based on Markov Random Prediction for Hybrid Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Yanzi Wang

    2016-01-01

    Full Text Available Over the last few years; issues regarding the use of hybrid energy storage systems (HESSs in hybrid electric vehicles have been highlighted by the industry and in academic fields. This paper proposes a fuzzy-logic power management strategy based on Markov random prediction for an active parallel battery-UC HESS. The proposed power management strategy; the inputs for which are the vehicle speed; the current electric power demand and the predicted electric power demand; is used to distribute the electrical power between the battery bank and the UC bank. In this way; the battery bank power is limited to a certain range; and the peak and average charge/discharge power of the battery bank and overall loss incurred by the whole HESS are also reduced. Simulations and scaled-down experimental platforms are constructed to verify the proposed power management strategy. The simulations and experimental results demonstrate the advantages; feasibility and effectiveness of the fuzzy-logic power management strategy based on Markov random prediction.

  4. Energy Management System with Equalization Algorithm for Distributed Energy Storage Systems in PV-Active Generator Based Low Voltage DC Microgrids

    DEFF Research Database (Denmark)

    Aldana, Nelson Leonardo Diaz; Hernández, Adriana Carolina Luna; Vasquez, Juan Carlos

    2015-01-01

    resistor of local droop control loops at each distributed energy storage system. The proposed strategy, can be used as an additional function of the microgrid energy management system where the state of charge of distributed ESS is equalized within a determined window of time. Finally, real-time simulation...

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

    Science.gov (United States)

    Hammerstrom, Donald J.

    2016-05-03

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

  6. Occupancy-based demand response and thermal comfort optimization in microgrids with renewable energy sources and energy storage

    NARCIS (Netherlands)

    Korkas, C; Baldi, S.; Michailidis, I; Kosmatopoulos, EB

    2016-01-01

    Integration of renewable energy sources in microgrids can be achieved via demand response programs, which change the electric usage in response to changes in the availability and price of electricity over time. This paper presents a novel control algorithm for joint demand response management and

  7. Optimal Real-Time Scheduling for Hybrid Energy Storage Systems and Wind Farms Based on Model Predictive Control

    Directory of Open Access Journals (Sweden)

    Meng Xiong

    2015-08-01

    Full Text Available Energy storage devices are expected to be more frequently implemented in wind farms in near future. In this paper, both pumped hydro and fly wheel storage systems are used to assist a wind farm to smooth the power fluctuations. Due to the significant difference in the response speeds of the two storages types, the wind farm coordination with two types of energy storage is a problem. This paper presents two methods for the coordination problem: a two-level hierarchical model predictive control (MPC method and a single-level MPC method. In the single-level MPC method, only one MPC controller coordinates the wind farm and the two storage systems to follow the grid scheduling. Alternatively, in the two-level MPC method, two MPC controllers are used to coordinate the wind farm and the two storage systems. The structure of two level MPC consists of outer level and inner level MPC. They run alternatively to perform real-time scheduling and then stop, thus obtaining long-term scheduling results and sending some results to the inner level as input. The single-level MPC method performs both long- and short-term scheduling tasks in each interval. The simulation results show that the methods proposed can improve the utilization of wind power and reduce wind power spillage. In addition, the single-level MPC and the two-level MPC are not interchangeable. The single-level MPC has the advantage of following the grid schedule while the two-level MPC can reduce the optimization time by 60%.

  8. Recent advances in metal oxide-based electrode architecture design for electrochemical energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Jian; Liu, Jinping; Huang, Xintang [Institute of Nanoscience and Nanotechnology, Department of Physics, Central China Normal University, Wuhan, Hubei (China); Li, Yuanyuan [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan (China); Yuan, Changzhou; Lou, Xiong Wen [School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore (China)

    2012-10-02

    Metal oxide nanostructures are promising electrode materials for lithium-ion batteries and supercapacitors because of their high specific capacity/capacitance, typically 2-3 times higher than that of the carbon/graphite-based materials. However, their cycling stability and rate performance still can not meet the requirements of practical applications. It is therefore urgent to improve their overall device performance, which depends on not only the development of advanced electrode materials but also in a large part ''how to design superior electrode architectures''. In the article, we will review recent advances in strategies for advanced metal oxide-based hybrid nanostructure design, with the focus on the binder-free film/array electrodes. These binder-free electrodes, with the integration of unique merits of each component, can provide larger electrochemically active surface area, faster electron transport and superior ion diffusion, thus leading to substantially improved cycling and rate performance. Several recently emerged concepts of using ordered nanostructure arrays, synergetic core-shell structures, nanostructured current collectors, and flexible paper/textile electrodes will be highlighted, pointing out advantages and challenges where appropriate. Some future electrode design trends and directions are also discussed. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Recent advances in metal oxide-based electrode architecture design for electrochemical energy storage.

    Science.gov (United States)

    Jiang, Jian; Li, Yuanyuan; Liu, Jinping; Huang, Xintang; Yuan, Changzhou; Lou, Xiong Wen David

    2012-10-02

    Metal oxide nanostructures are promising electrode materials for lithium-ion batteries and supercapacitors because of their high specific capacity/capacitance, typically 2-3 times higher than that of the carbon/graphite-based materials. However, their cycling stability and rate performance still can not meet the requirements of practical applications. It is therefore urgent to improve their overall device performance, which depends on not only the development of advanced electrode materials but also in a large part "how to design superior electrode architectures". In the article, we will review recent advances in strategies for advanced metal oxide-based hybrid nanostructure design, with the focus on the binder-free film/array electrodes. These binder-free electrodes, with the integration of unique merits of each component, can provide larger electrochemically active surface area, faster electron transport and superior ion diffusion, thus leading to substantially improved cycling and rate performance. Several recently emerged concepts of using ordered nanostructure arrays, synergetic core-shell structures, nanostructured current collectors, and flexible paper/textile electrodes will be highlighted, pointing out advantages and challenges where appropriate. Some future electrode design trends and directions are also discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Fuzzy-Logic-Based Gain-Scheduling Control for State-of-Charge Balance of Distributed Energy Storage Systems for DC Microgrids

    DEFF Research Database (Denmark)

    Aldana, Nelson Leonardo Diaz; Dragicevic, Tomislav; Vasquez, Juan Carlos

    2014-01-01

    -charge or deep-discharge in one of the energy storage units. Primary control in a microgrid is responsible for power sharing among units; and droop control is typically used in this stage. This paper proposes a modular and decentralized gain-scheduling control strategy based on fuzzy logic that ensures balanced...

  11. Hierarchical architecture for flexible energy storage.

    Science.gov (United States)

    Pan, H; Ma, J; Tao, J; Zhu, S

    2017-05-25

    The introduction of hierarchy and chirality into structure is of great interest, and can result in new optical and electronic properties due to the synergistic effect of helical and anisotropic structures. Herein, we demonstrate a simple and straightforward route toward the fabrication of hierarchical chiral materials based on the assembly of two-dimensional graphene oxide nanosheets (GO) and one-dimensional cellulose nanocrystals (CNCs). The unique layered structure of CNC/GO could be preserved in the solid state, allowing electrode active SnO 2 to be loaded for potential applications in energy storage. The resultant SnO 2 /CNC/reduced GO (SnO 2 /CNC/rGO) composite could be processed into film, fiber, and textile with an extremely high tensile strength of 100 MPa. The free-standing SnO 2 /CNC/rGO electrodes exhibit highly improved energy storage performance, with a reversible capacity of ∼500 mA h g -1 maintained for 1500 cycles in the film and ∼800 mA h g -1 maintained for 150 cycles in the textile at a current density of 500 mA g -1 . This is attributed to the prepared hierarchical chiral structures. The presented technique provides an effective approach to producing hierarchical functional materials from nanoparticles as building blocks, which might open an avenue for the creation of new flexible energy storage devices.

  12. Battery energy storage market feasibility study - Expanded report

    International Nuclear Information System (INIS)

    Kraft, S.; Akhil, A.

    1997-09-01

    Under the sponsorship of the US Department of Energy's Office of Utility Technologies, the Energy Storage Systems Analysis and Development Department at Sandia National Laboratories (SNL) contracted Frost and Sullivan to conduct a market feasibility study of energy storage systems. The study was designed specifically to quantify the battery energy storage market for utility applications. This study was based on the SNL Opportunities Analysis performed earlier. Many of the groups surveyed, which included electricity providers, battery energy storage vendors, regulators, consultants, and technology advocates, viewed battery storage as an important technology to enable increased use of renewable energy and as a means to solve power quality and asset utilization issues. There are two versions of the document available, an expanded version (approximately 200 pages, SAND97-1275/2) and a short version (approximately 25 pages, SAND97-1275/1)

  13. Nanostructures for Electrical Energy Storage (NEES) EFRC

    Data.gov (United States)

    Federal Laboratory Consortium — The Nanostructures for Electrical Energy Storage (NEES) EFRC is a multi-institutional research center, one of 46 Energy Frontier Research Centers established by the...

  14. Performance Analysis of Cold Energy Recovery from CO2 Injection in Ship-Based Carbon Capture and Storage (CCS

    Directory of Open Access Journals (Sweden)

    Hwalong You

    2014-11-01

    Full Text Available Carbon capture and storage (CCS technology is one of the practical solutions for mitigating the effects of global warming. When captured CO2 is injected into storage sites, the CO2 is subjected to a heating process. In a conventional CO2 injection system, CO2 cold energy is wasted during this heating process. This study proposes a new CO2 injection system that takes advantage of the cold energy using the Rankine cycle. The study compared the conventional system with the new CO2 injection system in terms of specific net power consumption, exergy efficiency, and life-cycle cost (LCC to estimate the economic effects. The results showed that the new system reduced specific net power consumption and yielded higher exergy efficiency. The LCC of the new system was more economical. Several cases were examined corresponding to different conditions, specifically, discharge pressure and seawater temperature. This information may affect decision-making when CCS projects are implemented.

  15. Concrete thermal energy storage for steam generation: A numerical investigation

    DEFF Research Database (Denmark)

    Singh, Shobhana; Sørensen, Kim

    2017-01-01

    the heat exchanger tubes embedded in a cylindrical shape concrete configuration. Three-dimensional multiphysics model of the storage system is developed to investigate transient conjugate heat transfer between the two mediums, the heat transfer fluid, and the concrete. The model comprehends the dynamics...... of storing thermal energy in the storage at the temperature range of 350??390 C. To evaluate the performance of the storage system using finned heat exchanger tubes, thermal characteristics such as charging/discharging time, energy, and exergy efficiency are predicted. The developed model satisfactorily......Establishing enhancement methods to develop cost-effective thermal energy storage technology requires a detailed analysis. In this paper, a numerical investigation of the concrete based thermal energy storage system is carried out. The storage system consists of a heat transfer fluid flowing inside...

  16. Graphene-based Material Systems for Nanoelectronics and Energy Storage Devices

    Science.gov (United States)

    Guo, Shirui

    hybrids provides an attractive pathway for the fabrication of novel 3-Dimensional hybrid nanostructures. The second type hybrid is graphene oxide (GO) and SWCNT composite ink (GO-SWCNT ink). SWCNTs are dispersed using a GO aqueous solution (2mg/ml) with sonication support to achieve a SWCNT concentration of 12mg/ml, the highest reported value so far without surfactant assistance. Paper based electrodes for supercapacitors are fabricated using GO-SWCNT composite ink via dip casting method. By employing different concentrations of SWCNT inside the ink, supercapacitors demonstrated different capacitance values. The highest value of specific capacitance reaches up to 295 F/g at a current density of 0.5A/g with a GO/SWCNT weight ratio of 1:5. The cycling stability for the GO-SWCNT paper electrode supercapacitors indicates capacitance retention of 85% over 60,000 cycles. Finally, engineered interactions between nanomaterials, polymers, molecules and graphene/carbon nanotube can lead to the development of new types of devices for myriad applications.

  17. Compressed Air Energy Storage in Denmark

    DEFF Research Database (Denmark)

    Salgi, Georges Garabeth; Lund, Henrik

    2006-01-01

    Compressed air energy storage system (CAES) is a technology which can be used for integrating more fluctuating renewable energy sources into the electricity supply system. On a utility scale, CAES has a high feasibility potential compared to other storage technologies. Here, the technology...

  18. Federal Tax Incentives for Energy Storage Systems

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Katherine H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Elgqvist, Emma M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Settle, Donald E [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-01-16

    Investments in renewable energy are more attractive due to the contribution of two key federal tax incentives. The investment tax credit (ITC) and the Modified Accelerated Cost Recovery System (MACRS) depreciation deduction may apply to energy storage systems such as batteries depending on who owns the battery and how the battery is used. The guidelines in this fact sheet apply to energy storage systems installed at the same time as the renewable energy system.

  19. A Comprehensive Review of Thermal Energy Storage

    Directory of Open Access Journals (Sweden)

    Ioan Sarbu

    2018-01-01

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

  20. Superconducting magnetic energy storage for electric utilities and fusion systems

    International Nuclear Information System (INIS)

    Rogers, J.D.; Boenig, H.J.; Hassenzahl, W.V.

    1978-01-01

    Superconducting inductors provide a compact and efficient means of storing electrical energy without an intermediate conversion process. Energy storage inductors are under development for load leveling and transmission line stabilization in electric utility systems and for driving magnetic confinement and plasma heating coils in fusion energy systems. Fluctuating electric power demands force the electric utility industry to have more installed generating capacity than the average load requires. Energy storage can increase the utilization of base-load fossil and nuclear power plants for electric utilities. The Los Alamos Scientific Laboratory and the University of Wisconsin are developing superconducting magnetic energy storage (SMES) systems, which will store and deliver electrical energy for load leveling, peak shaving, and the stabilization of electric utility networks. In the fusion area, inductive energy transfer and storage is being developed. Both 1-ms fast-discharge theta-pinch systems and 1-to-2-s slow energy transfer tokamak systems have been demonstrated. The major components and the method of operation of a SMES unit are described, and potential applications of different size SMES systems in electric power grids are presented. Results are given of a reference design for a 10-GWh unit for load leveling, of a 30-MJ coil proposed for system stabilization, and of tests with a small-scale, 100-kJ magnetic energy storage system. The results of the fusion energy storage and transfer tests are presented. The common technology base for the various storage systems is discussed

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

    Science.gov (United States)

    Perera, Sanjaya Dulip

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

  2. Microencapsulated n-octadecane with different methylmethacrylate-based copolymer shells as phase change materials for thermal energy storage

    International Nuclear Information System (INIS)

    Qiu, Xiaolin; Li, Wei; Song, Guolin; Chu, Xiaodong; Tang, Guoyi

    2012-01-01

    Microcapsules containing n-octadecane with different methylmethacrylate (MMA (methyl methacrylate))-based copolymer shells were fabricated by a suspension-like polymerization. Butyl acrylate (BA), butyl methacrylate (BMA), lauryl methacrylate (LMA) and stearyl methacrylate (SMA) were employed as monomers to copolymerize with MMA. Pentaerythritol tetraacrylate (PETRA) was employed as a crosslinking agent. The (microencapsulted phase change materials) MicroPCMs were characterized using Fourier transformed infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Thermal properties and thermal resistances of MicroPCMs were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), respectively. Phase change enthalpies and PCM contents of MicroPCMs increased with the length decreasing of the side chain of the monomers. The n-octadecane content of as much as 77.3% can be obtained in the crosslinked MicroPCMs with P(MMA-co-BMA) as shell, and accompanied by the highest melting enthalpy (173.7 J/g) and crystallization enthalpy (174.4 J/g). Heat capacities of crosslinked MicroPCMs are higher than those of their uncrosslinked counterparts. The crosslinked MicroPCMs exhibit significantly greater thermal stabilities compared with their uncrosslinked counterparts and the n-ontadecane bulk. The crosslinked MicroPCMs with P(MMA-co-SMA) displays the highest thermal resistance temperature up to 255 °C. Therefore, MicroPCMs with MMA-based copolymer as shells, especially crosslinked copolymer shells, show excellent potentials for thermal energy storage. -- Highlights: ► n-Octadecane was encapsulated with methylmethacrylate(MMA)-based copolymer shells. ► n-Octadecane content of Microcapsules increased with length decreasing of side chain of monomers. ► Microcapsule with P(MMA-co-butyl methacrylate) has the highest latent heat. ► Microcapsule with P(MMA-co-stearyl methacrylate) has the greatest thermal stability.

  3. Hybrid Hydrogen and Mechanical Distributed Energy Storage

    Directory of Open Access Journals (Sweden)

    Stefano Ubertini

    2017-12-01

    Full Text Available Effective energy storage technologies represent one of the key elements to solving the growing challenges of electrical energy supply of the 21st century. Several energy storage systems are available, from ones that are technologically mature to others still at a research stage. Each technology has its inherent limitations that make its use economically or practically feasible only for specific applications. The present paper aims at integrating hydrogen generation into compressed air energy storage systems to avoid natural gas combustion or thermal energy storage. A proper design of such a hybrid storage system could provide high roundtrip efficiencies together with enhanced flexibility thanks to the possibility of providing additional energy outputs (heat, cooling, and hydrogen as a fuel, in a distributed energy storage framework. Such a system could be directly connected to the power grid at the distribution level to reduce power and energy intermittence problems related to renewable energy generation. Similarly, it could be located close to the user (e.g., office buildings, commercial centers, industrial plants, hospitals, etc.. Finally, it could be integrated in decentralized energy generation systems to reduce the peak electricity demand charges and energy costs, to increase power generation efficiency, to enhance the security of electrical energy supply, and to facilitate the market penetration of small renewable energy systems. Different configurations have been investigated (simple hybrid storage system, regenerate system, multistage system demonstrating the compressed air and hydrogen storage systems effectiveness in improving energy source flexibility and efficiency, and possibly in reducing the costs of energy supply. Round-trip efficiency up to 65% can be easily reached. The analysis is conducted through a mixed theoretical-numerical approach, which allows the definition of the most relevant physical parameters affecting the system

  4. Regenesys utility scale energy storage. Project summary

    International Nuclear Information System (INIS)

    2004-01-01

    This report summarises the work to date, the current situation and the future direction of a project carried out by Regenesys Technology Ltd. (RGN) to investigate the benefits of electrochemical energy storage for power generators using renewable energy sources focussing on wind energy. The background to the study is traced covering the progress of the Regenesys energy storage technology, and the milestones achieved and lessons learnt. Details are given of the planned renewable-store-market interface to allow renewable generators optimise revenue under the New Electricity Trading Arrangements (NETA) and help in the connection of the renewable energy to the electric grid system. The four integrated work programmes of the project are described and involve a system study examining market penetration of renewable generators, a technical study into connection of renewable generators and energy storage, a small scale demonstration, and a pilot scale energy storage plant at Little Barton in Cambridgeshire. Problems leading to the closure of the project are discussed

  5. Effective energy storage from a triboelectric nanogenerator.

    Science.gov (United States)

    Zi, Yunlong; Wang, Jie; Wang, Sihong; Li, Shengming; Wen, Zhen; Guo, Hengyu; Wang, Zhong Lin

    2016-03-11

    To sustainably power electronics by harvesting mechanical energy using nanogenerators, energy storage is essential to supply a regulated and stable electric output, which is traditionally realized by a direct connection between the two components through a rectifier. However, this may lead to low energy-storage efficiency. Here, we rationally design a charging cycle to maximize energy-storage efficiency by modulating the charge flow in the system, which is demonstrated on a triboelectric nanogenerator by adding a motion-triggered switch. Both theoretical and experimental comparisons show that the designed charging cycle can enhance the charging rate, improve the maximum energy-storage efficiency by up to 50% and promote the saturation voltage by at least a factor of two. This represents a progress to effectively store the energy harvested by nanogenerators with the aim to utilize ambient mechanical energy to drive portable/wearable/implantable electronics.

  6. Compressed air energy storage with liquid air capacity extension

    International Nuclear Information System (INIS)

    Kantharaj, Bharath; Garvey, Seamus; Pimm, Andrew

    2015-01-01

    Highlights: • A hybrid energy storage system involving compressed air and liquid air is proposed. • Thermodynamic analysis based on exergy is carried out on the proposed system. • Turnaround efficiency is comparable to energy recovery from pure liquid air systems. • Storage duration is critical for economic viability of the proposed system. - Abstract: As renewable electricity generation capacity increases, energy storage will be required at larger scales. Compressed Air Energy Storage (CAES) at large scales, with effective management of heat, is recognised to have potential to provide affordable grid-scale energy storage. Where suitable geologies are unavailable, compressed air could be stored in pressurised steel tanks above ground, but this would incur significant storage costs. Liquid Air Energy Storage (LAES), on the other hand, does not need a pressurised storage vessel, can be located almost anywhere, has a relatively large volumetric exergy density at ambient pressure, and has relatively low marginal cost of energy storage capacity even at modest scales. However, it has lower roundtrip efficiency than compressed air energy storage technologies. This paper carries out thermodynamic analyses for an energy storage installation comprising a compressed air component supplemented with a liquid air store, and additional machinery to transform between gaseous air at ambient temperature and high pressure, and liquid air at ambient pressure. A roundtrip efficiency of 42% is obtained for the conversion of compressed air at 50 bar to liquid air, and back. The proposed system is more economical than pure LAES and more economical than a pure CAES installation if the storage duration is sufficiently long and if the high-pressure air store cannot exploit some large-scale geological feature.

  7. Research progress about chemical energy storage of solar energy

    Science.gov (United States)

    Wu, Haifeng; Xie, Gengxin; Jie, Zheng; Hui, Xiong; Yang, Duan; Du, Chaojun

    2018-01-01

    In recent years, the application of solar energy has been shown obvious advantages. Solar energy is being discontinuity and inhomogeneity, so energy storage technology becomes the key to the popularization and utilization of solar energy. Chemical storage is the most efficient way to store and transport solar energy. In the first and the second section of this paper, we discuss two aspects about the solar energy collector / reactor, and solar energy storage technology by hydrogen production, respectively. The third section describes the basic application of solar energy storage system, and proposes an association system by combining solar energy storage and power equipment. The fourth section briefly describes several research directions which need to be strengthened.

  8. Carbonless Transportation and Energy Storage in Future Energy Systems

    Science.gov (United States)

    Berry, G. D.; Lamont, A. D.

    2001-01-01

    Electricity is the highest quality energy carrier, increasingly dominant throughout the world's energy infrastructure. Ultimately electricity use can expand to efficiently meet virtually all stationary energy applications, eliminating stationary end-use carbon emissions. This approach is unlikely to work in transportation, however, due to the high cost and low energy density of electricity storage. Chemical energy carriers, such as hydrogen, can more effectively serve transportation fuel and energy storage applications, offering much higher energy density at lower cost. Electrolytic hydrogen, extracted from steam with renewable energy, stored as a high pressure gas or cryogenic liquid, and reconverted to electricity in fuel cells and or used to power hydrogen vehicles, will reduce emissions from both transportation and electric generation. Renewable resources and modular electrolytic technology also permit decentralized hydrogen production, circumventing distribution issues and barriers to market entry. In contrast, sequestration-based fossil-fueled systems must achieve economies of scale by relying on centralized production and hierarchical transmission and distribution of electricity, hydrogen fuel, and carbon (dioxide).

  9. Aquifer Thermal Energy Storage for Seasonal Thermal Energy Balance

    Science.gov (United States)

    Rostampour, Vahab; Bloemendal, Martin; Keviczky, Tamas

    2017-04-01

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

  10. ENERGY EFFICIENCY AND ENVIRONMENTALLY FRIENDLY DISTRIBUTED ENERGY STORAGE BATTERY

    Energy Technology Data Exchange (ETDEWEB)

    LANDI, J.T.; PLIVELICH, R.F.

    2006-04-30

    Electro Energy, Inc. conducted a research project to develop an energy efficient and environmentally friendly bipolar Ni-MH battery for distributed energy storage applications. Rechargeable batteries with long life and low cost potentially play a significant role by reducing electricity cost and pollution. A rechargeable battery functions as a reservoir for storage for electrical energy, carries energy for portable applications, or can provide peaking energy when a demand for electrical power exceeds primary generating capabilities.

  11. The Role of Energy Storage in Commercial Building

    Energy Technology Data Exchange (ETDEWEB)

    Kintner-Meyer, Michael CW; Subbarao, Krishnappa; Prakash Kumar, Nirupama; Bandyopadhyay, Gopal K.; Finley, C.; Koritarov, V. S.; Molburg, J. C.; Wang, J.; Zhao, Fuli; Brackney, L.; Florita, A. R.

    2010-09-30

    Motivation and Background of Study This project was motivated by the need to understand the full value of energy storage (thermal and electric energy storage) in commercial buildings, the opportunity of benefits for building operations and the potential interactions between a building and a smart grid infrastructure. On-site or local energy storage systems are not new to the commercial building sector; they have been in place in US buildings for decades. Most building-scale storage technologies are based on thermal or electrochemical storage mechanisms. Energy storage technologies are not designed to conserve energy, and losses associated with energy conversion are inevitable. Instead, storage provides flexibility to manage load in a building or to balance load and generation in the power grid. From the building owner's perspective, storage enables load shifting to optimize energy costs while maintaining comfort. From a grid operations perspective, building storage at scale could provide additional flexibility to grid operators in managing the generation variability from intermittent renewable energy resources (wind and solar). To characterize the set of benefits, technical opportunities and challenges, and potential economic values of storage in a commercial building from both the building operation's and the grid operation's view-points is the key point of this project. The research effort was initiated in early 2010 involving Argonne National Laboratory (ANL), the National Renewable Energy Laboratory (NREL), and Pacific Northwest National Laboratory (PNNL) to quantify these opportunities from a commercial buildings perspective. This report summarizes the early discussions, literature reviews, stakeholder engagements, and initial results of analyses related to the overall role of energy storage in commercial buildings. Beyond the summary of roughly eight months of effort by the laboratories, the report attempts to substantiate the importance of

  12. Compact inductive energy storage pulse power system.

    Science.gov (United States)

    K, Senthil; Mitra, S; Roy, Amitava; Sharma, Archana; Chakravarthy, D P

    2012-05-01

    An inductive energy storage pulse power system is being developed in BARC, India. Simple, compact, and robust opening switches, capable of generating hundreds of kV, are key elements in the development of inductive energy storage pulsed power sources. It employs an inductive energy storage and opening switch power conditioning techniques with high energy density capacitors as the primary energy store. The energy stored in the capacitor bank is transferred to an air cored storage inductor in 5.5 μs through wire fuses. By optimizing the exploding wire parameters, a compact, robust, high voltage pulse power system, capable of generating reproducibly 240 kV, is developed. This paper presents the full details of the system along with the experimental data.

  13. Hybrid Electric Energy Storages: Their Specific Features and Application (Review)

    Science.gov (United States)

    Popel', O. S.; Tarasenko, A. B.

    2018-05-01

    The article presents a review of various aspects related to development and practical use of hybrid electric energy storages (i.e., those uniting different energy storage technologies and devices in an integrated system) in transport and conventional and renewable power engineering applications. Such devices, which were initially developed for transport power installations, are increasingly being used by other consumers characterized by pronounced nonuniformities of their load schedule. A range of tasks solved using such energy storages is considered. It is shown that, owing to the advent of new types of energy storages and the extended spectrum of their performance characteristics, new possibilities for combining different types of energy storages and for developing hybrid systems have become available. This, in turn, opens up the possibility of making energy storages with better mass and dimension characteristics and achieving essentially lower operational costs. The possibility to secure more comfortable (base) operating modes of primary sources of energy (heat engines and renewable energy source based power installations) and to achieve a higher capacity utilization factor are unquestionable merits of hybrid energy storages. Development of optimal process circuit solutions, as well as energy conversion and control devices facilitating the fullest utilization of the properties of each individual energy storage included in the hybrid system, is among the important lines of research carried out in this field in Russia and abroad. Our review of existing developments has shown that there are no universal technical solutions in this field (the specific features of a consumer have an essential effect on the process circuit solutions and on the composition of a hybrid energy storage), a circumstance that dictates the need to extend the scope of investigations in this promising field.

  14. Centrifugal Spinning and Its Energy Storage Applications

    Science.gov (United States)

    Yao, Lu

    Lithium-ion batteries (LIBs) and supercapacitors are important electrochemical energy storage systems. LIBs have high specific energy density, long cycle life, good thermal stability, low self-discharge, and no memory effect. However, the low abundance of Li in the Earth's crust and the rising cost of LIBs urge the attempts to develop alternative energy storage systems. Recently, sodium-ion batteries (SIBs) have become an attractive alternative to LIBs due to the high abundance and low cost of Na. Although the specific capacity and energy density of SIBs are not as high as LIBs, SIBs can still be promising power sources for certain applications such as large-scale, stationary grids. Supercapacitors are another important class of energy storage devices. Electric double-layer capacitors (EDLCs) are one important type of supercapacitors and they exhibit high power density, long cycle life, excellent rate capability and environmental friendliness. The potential applications of supercapacitors include memory protection in electronic circuitry, consumer portable electronic devices, and electrical hybrid vehicles. The electrochemical performance of SIBs and EDLCs is largely dependent on the electrode materials. Therefore, development of superior electrodes is the key to achieve highperformance alternative energy storage systems. Recently, one-dimensional nano-/micro-fiber based electrodes have become promising candidates in energy storage because they possess a variety of desirable properties including large specific surface area, well-guided ionic/electronic transport, and good electrode-electrolyte contact, which contribute to enhanced electrochemical performance. Currently, most nano-/micro-fiber based electrodes are prepared via electrospinning method. However, the low production rate of this approach hinders its practical application in the production of fibrous electrodes. Thus, it is significantly important to employ a rapid, low-cost and scalable nano

  15. Perspectives on energy storage wheels for space station application

    Science.gov (United States)

    Oglevie, R. E.

    1984-01-01

    Several of the issues of the workshop are addressed from the perspective of a potential Space Station developer and energy wheel user. Systems' considerations are emphasized rather than component technology. The potential of energy storage wheel (ESW) concept is discussed. The current status of the technology base is described. Justification for advanced technology development is also discussed. The study concludes that energy storage in wheels is an attractive concept for immediate technology development and future Space Station application.

  16. 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

  17. Efficiency of Compressed Air Energy Storage

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Brix, Wiebke

    2011-01-01

    The simplest type of a Compressed Air Energy Storage (CAES) facility would be an adiabatic process consisting only of a compressor, a storage and a turbine, compressing air into a container when storing and expanding when producing. This type of CAES would be adiabatic and would if the machines...... were reversible have a storage efficiency of 100%. However, due to the specific capacity of the storage and the construction materials the air is cooled during and after compression in practice, making the CAES process diabatic. The cooling involves exergy losses and thus lowers the efficiency...... of the storage significantly. The efficiency of CAES as an electricity storage may be defined in several ways, we discuss these and find that the exergetic efficiency of compression, storage and production together determine the efficiency of CAES. In the paper we find that the efficiency of the practical CAES...

  18. Carbon Nanotubes as Future Energy Storage System

    OpenAIRE

    Vasu , V; Silambarasan , D

    2017-01-01

    International audience; Hydrogen is considered to be a clean energy carrier. At present the main drawback in using hydrogen as the fuel is the lack of proper hydrogen storage vehicle, thus ongoing research is focused on the development of advance hydrogen storage materials. Many alloys are able to store hydrogen reversibly, but the gravimetric storage density is too low for any practical applications. Theoretical studies have predicted that interaction of hydrogen with carbon nanotubes is by ...

  19. Thermo-Economic Comparison and Parametric Optimizations among Two Compressed Air Energy Storage System Based on Kalina Cycle and ORC

    Directory of Open Access Journals (Sweden)

    Ruixiong Li

    2016-12-01

    Full Text Available The compressed air energy storage (CAES system, considered as one method for peaking shaving and load-levelling of the electricity system, has excellent characteristics of energy storage and utilization. However, due to the waste heat existing in compressed air during the charge stage and exhaust gas during the discharge stage, the efficient operation of the conventional CAES system has been greatly restricted. The Kalina cycle (KC and organic Rankine cycle (ORC have been proven to be two worthwhile technologies to fulfill the different residual heat recovery for energy systems. To capture and reuse the waste heat from the CAES system, two systems (the CAES system combined with KC and ORC, respectively are proposed in this paper. The sensitivity analysis shows the effect of the compression ratio and the temperature of the exhaust on the system performance: the KC-CAES system can achieve more efficient operation than the ORC-CAES system under the same temperature of exhaust gas; meanwhile, the larger compression ratio can lead to the higher efficiency for the KC-CAES system than that of ORC-CAES with the constant temperature of the exhaust gas. In addition, the evolutionary multi-objective algorithm is conducted between the thermodynamic and economic performances to find the optimal parameters of the two systems. The optimum results indicate that the solutions with an exergy efficiency of around 59.74% and 53.56% are promising for KC-CAES and ORC-CAES system practical designs, respectively.

  20. Optimal Scheduling for Energy Harvesting Transmitters with Hybrid Energy Storage

    OpenAIRE

    Ozel, Omur; Shahzad, Khurram; Ulukus, Sennur

    2013-01-01

    We consider data transmission with an energy harvesting transmitter which has a hybrid energy storage unit composed of a perfectly efficient super-capacitor (SC) and an inefficient battery. The SC has finite space for energy storage while the battery has unlimited space. The transmitter can choose to store the harvested energy in the SC or in the battery. The energy is drained from the SC and the battery simultaneously. In this setting, we consider the offline throughput maximization problem ...

  1. 4th international renewable energy storage conference (IRES 2009)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    ) Renewable power (to) methane solution for renewable power integration and energy storage (M. Sterner); (20) Multi-source energy storage system integrated in buildings (MESSIB) (J. Gravalos); (21) Heat storage technologies for buildings with high solar fractions (H.Kerskes); (22) Solar combisystems and storage: The way to achieve high solar fraction (G. Tanguy); (23) LCA of 100% solar fraction thermal supply to a Swiss apartment building using water-based sensible heat storage (A. Simons); (24) WKSP Evaluation and optimisation of UTES systems of energy efficient office buildings (M.N. Fisch); (25) High-temperature storage for solar tower power plants (S. Zunft); (25) The power matching city field test (R. Kamphuis); (26) Smart energy storage: The sol-ion project (M. Lippert); (27) Wind diesel hybrid systems, engines to support wind power (C. Dommermuth); (28) BYD Energy storage system (C. Beck); (29) Zebra battery (M. Vona); (30) Grid-connected storage systems workshop (P. Malbranche); (31) Testing grid connected storage systems (M. Perrin); (32) Electrical storage applications and characteristics (P. Noegaard).

  2. Energy storage for a lunar base by the reversible chemical reaction: CaO+H2O reversible reaction Ca(OH)2

    Science.gov (United States)

    Perez-Davis, Marla E.; Difilipo, Frank

    1990-01-01

    A thermochemical solar energy storage concept involving the reversible reaction CaO + H2O yields Ca(OH)2 is proposed as a power system element for a lunar base. The operation and components of such a system are described. The CaO/H2O system is capable of generating electric power during both the day and night. The specific energy (energy to mass ratio) of the system was estimated to be 155 W-hr/kg. Mass of the required amount of CaO is neglected since it is obtained from lunar soil. Potential technical problems, such as reactor design and lunar soil processing, are reviewed.

  3. Mixed Solutions of Electrical Energy Storage

    Directory of Open Access Journals (Sweden)

    Chioncel Cristian Paul

    2012-01-01

    Full Text Available The paper presents electrical energy storage solutions using electricbatteries and supercapacitors powered from photovoltaic solarmodules, with possibilities of application in electric and hybrid vehicles.The future development of electric cars depends largely on electricalenergy storage solutions that should provide a higher range of roadand operating parameters comparable to those equipped with internalcombustion engines, that eliminate pollution.

  4. Energy storage on board of railway vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, M.; Scholten, J. [Bombardier Transportation, Mannheim (Germany)

    2004-07-01

    The proposed energy storage on board of a Railway vehicle leads to a big step in the reduction of consumed energy. Up to 30% energy saving are expected in a light rail vehicle, at the same time reducing the peak power demand drastically. In addition, with the energy storage an operation without catenary could become reality, which was successfully demonstrated with the prototype light rail vehicle driving with switched off pantograph. This prototype vehicle is in passenger operation since September 2003, the implemented software is optimised on energy savings and first experience is very promising. (authors)

  5. Oil drilling rig diesel power-plant fuel efficiency improvement potentials through rule-based generator scheduling and utilization of battery energy storage system

    International Nuclear Information System (INIS)

    Pavković, Danijel; Sedić, Almir; Guzović, Zvonimir

    2016-01-01

    Highlights: • Isolated oil drilling rig microgrid power flows are analyzed over 30 days. • Rule-based diesel generator scheduling is proposed to reduce fuel consumption. • A battery energy storage is parameterized and used for peak load leveling. • The effectiveness of proposed hybrid microgrid is verified by simulations. • Return-of-investment might be expected within 20% of battery system lifetime. - Abstract: This paper presents the development of a rule-based energy management control strategy suitable for isolated diesel power-plants equipped with a battery energy storage system for peak load shaving. The proposed control strategy includes the generator scheduling strategy and peak load leveling scheme based on current microgrid active and reactive power requirements. In order to investigate the potentials for fuel expenditure reduction, 30 days-worth of microgrid power flow data has been collected on an isolated land-based oil drilling rig powered by a diesel generator power-plant, characterized by highly-variable active and reactive load profiles due to intermittent engagements and disengagements of high-power electric machinery such as top-drive, draw-works and mud-pump motors. The analysis has indicated that by avoiding the low-power operation of individual generators and by providing the peak power requirements (peak shaving) from a dedicated energy storage system, the power-plant fuel efficiency may be notably improved. An averaged power flow simulation model has been built, comprising the proposed rule-based power flow control strategy and the averaged model of a suitably sized battery energy storage system equipped with grid-tied power converter and state-of-charge control system. The effectiveness of the proposed rule-based strategy has been evaluated by means of computer simulation analysis based on drilling rig microgrid active and reactive power data recorded during the 30 day period. The analysis has indicated that fuel consumption of

  6. Hydrogen Storage Technologies for Future Energy Systems.

    Science.gov (United States)

    Preuster, Patrick; Alekseev, Alexander; Wasserscheid, Peter

    2017-06-07

    Future energy systems will be determined by the increasing relevance of solar and wind energy. Crude oil and gas prices are expected to increase in the long run, and penalties for CO 2 emissions will become a relevant economic factor. Solar- and wind-powered electricity will become significantly cheaper, such that hydrogen produced from electrolysis will be competitively priced against hydrogen manufactured from natural gas. However, to handle the unsteadiness of system input from fluctuating energy sources, energy storage technologies that cover the full scale of power (in megawatts) and energy storage amounts (in megawatt hours) are required. Hydrogen, in particular, is a promising secondary energy vector for storing, transporting, and distributing large and very large amounts of energy at the gigawatt-hour and terawatt-hour scales. However, we also discuss energy storage at the 120-200-kWh scale, for example, for onboard hydrogen storage in fuel cell vehicles using compressed hydrogen storage. This article focuses on the characteristics and development potential of hydrogen storage technologies in light of such a changing energy system and its related challenges. Technological factors that influence the dynamics, flexibility, and operating costs of unsteady operation are therefore highlighted in particular. Moreover, the potential for using renewable hydrogen in the mobility sector, industrial production, and the heat market is discussed, as this potential may determine to a significant extent the future economic value of hydrogen storage technology as it applies to other industries. This evaluation elucidates known and well-established options for hydrogen storage and may guide the development and direction of newer, less developed technologies.

  7. Electricity storage. The problematic of alternative energies

    International Nuclear Information System (INIS)

    Hauet, Jean-Pierre

    2013-01-01

    After having evoked the increasing share of renewable energies in electricity production in Europe and the associated investments, the author outlines the main problems associated with renewable energy: their intermittency, and the fact that they are submitted to quick and important variations which must be managed by the grid. He also evokes economic and financial problems (high taxes in Germany and in France, mandatory purchase mechanisms leading to absurd situations and having consequences on the electricity market). The author discusses the issue of energy storage: storage is expensive and its cost will increase that of the produced energy. However, storage can be interesting if its cost is covered by the income generated by the provided services. Some solutions already exist: pumped-storage power station (PSPS), remotely controlled electric-storage water heaters. The author presents and comments the services which storage can provide: smoothing, spare energy supply, and supply quality. He outlines the importance of a technical-economic analysis for the choice of the best storage solution, but also the need to change the business model

  8. Energy storage. The actual challenge for tomorrow

    International Nuclear Information System (INIS)

    Combe, Matthieu; Danielo, Olivier

    2016-09-01

    As methods of energy production are now diversified and efficient, the challenge is now their integration into the grid, and their storage. Thus, this publication first proposes a set of articles which address perspectives and realisations (or projects) related to energy storage: the challenge of modernisation of Pump Storage Power plants (PSP), the possibilities provided by power-to-gas technology to store electricity, the possibilities provided by coupling of CO 2 storage and geothermal energy. Other aspects concern electric power storage at the back end of the supply chain: the Corri-door project of 200 terminals for fast electric charging (for electric vehicles), the emergence of the domestic battery as storage mean in different counties. More prospective projects are also evoked: the use of hot water in Hawaii to store photovoltaic solar electricity and inspired projects by ENGIE and EDF, the perspective of energy storage on miniaturised chips, and a three-wheel light vehicle (Moe) using solar energy and developed by the Evovelo startup

  9. Energy storage systems: power grid and energy market use cases

    Directory of Open Access Journals (Sweden)

    Komarnicki Przemysław

    2016-09-01

    Full Text Available Current power grid and market development, characterized by large growth of distributed energy sources in recent years, especially in Europa, are according energy storage systems an increasingly larger field of implementation. Existing storage technologies, e.g. pumped-storage power plants, have to be upgraded and extended by new but not yet commercially viable technologies (e.g. batteries or adiabatic compressed air energy storage that meet expected demands. Optimal sizing of storage systems and technically and economically optimal operating strategies are the major challenges to the integration of such systems in the future smart grid. This paper surveys firstly the literature on the latest niche applications. Then, potential new use case and operating scenarios for energy storage systems in smart grids, which have been field tested, are presented and discussed and subsequently assessed technically and economically.

  10. Relaxors Terpolymers for Energy Storage Capacitors

    National Research Council Canada - National Science Library

    Zhang, Qiming

    2005-01-01

    In this program, Penn State, TRS Technologies, and Electronic Concepts, Inc. (ECI) worked together to perform a preliminary investigation of various issues related to the ferroelectric relaxor terpolymer for energy storage capacitors...

  11. TES (Thermal Energy Storage) Video News Release

    Science.gov (United States)

    1994-01-01

    TES is an in-space technology experiment that flew on STS-62. Its intent is to investigate the behavior of two different thermal energy storage materials as they undergo repeated melting and freezing in the microgravity environment.

  12. Energy storage by means of exciton droplets

    Energy Technology Data Exchange (ETDEWEB)

    Zuev, V.A.; Litovchenko, V.G.

    1980-01-01

    Certain characteristics of electron-hole droplets and ball lightning are investigated and compared with a view to evaluating energy storage and transfer processes. Models for plasma processes in the atmosphere and in semiconductors are briefly examined.

  13. New energy storage concept uses tapes

    Science.gov (United States)

    Gruber, A.; Kafesjian, R. R.

    1966-01-01

    Energy storage system uses movable permeable tapes with cathode and electrolyte material that is drawn across an anode to produce electric power. The system features long shelf life, high efficiency, and flexible operation.

  14. Demand Response and Energy Storage Integration Study

    Energy Technology Data Exchange (ETDEWEB)

    Ookie Ma, Kerry Cheung

    2016-03-01

    Demand response and energy storage resources present potentially important sources of bulk power system services that can aid in integrating variable renewable generation. While renewable integration studies have evaluated many of the challenges associated with deploying large amounts of variable wind and solar generation technologies, integration analyses have not yet fully incorporated demand response and energy storage resources. This report represents an initial effort in analyzing the potential integration value of demand response and energy storage, focusing on the western United States. It evaluates two major aspects of increased deployment of demand response and energy storage: (1) Their operational value in providing bulk power system services and (2) Market and regulatory issues, including potential barriers to deployment.

  15. Multi-Agent-Based Controller for Voltage Enhancement in AC/DC Hybrid Microgrid Using Energy Storages

    Directory of Open Access Journals (Sweden)

    Ahmadali Khatibzadeh

    2017-02-01

    Full Text Available Development of renewable energies and DC loads have led microgrids toward the creation of DC networks. The predictions show that the hybrid microgrids will be used widely in the future. This article has studied the voltage stability in the presence of sources of energy storage in AC/DC hybrid networks. However, because the different dynamics of hybrid networks applying centralized and distributed controllers will be faced with different problems, in this study, a multi-agent control for the microgrid has been used. A new structure referred to here as an event-driven microgrid control management (EDMCM has been developed to control the microgrid. This method increases response speed and accuracy of decision making. Hybrid Network Simulation results confirm the validity of the developed model.

  16. Thin and flexible Ni-P based current collectors developed by electroless deposition for energy storage devices

    International Nuclear Information System (INIS)

    Wu, Haoran; Susanto, Amelia; Lian, Keryn

    2017-01-01

    Highlights: • A PET metallized by electroless nickel was developed as flexible current collector. • The Ni-PET current collector showed good conductivity and chemical stability. • The flexible nanocarbon electrodes with Ni-PET exhibited capacitive behavior. • The Ni-PET enabled electrodes performed nicely in liquid and solid supercapacitors. - Abstract: A PET film metalized by electroless nickel deposition was demonstrated as thin and flexible current collector for energy storage devices. The resultant nickel-on-PET film (Ni-PET) can be used both as current collector for electrochemical capacitors and as electrode for thin film batteries. The composition of Ni-PET was characterized by EDX and XPS. The electrochemical performance of the Ni-PET current collector was similar to Ni foil but with less hydrogen evolution at low potential. The Ni-PET film exhibited better flexibility than a metallic Ni foil. Carbon nanotubes were coated on a Ni-PET substrate to form an electrochemical capacitor electrode which exhibited high chemical stability in both liquid and solid electrolytes, showing strong promise for solid energy storage devices.

  17. Economic Operation of Supercritical CO2 Refrigeration Energy Storage Technology

    Science.gov (United States)

    Hay, Ryan

    With increasing penetration of intermittent renewable energy resources, improved methods of energy storage are becoming a crucial stepping stone in the path toward a smarter, greener grid. SuperCritical Technologies is a company based in Bremerton, WA that is developing a storage technology that can operate entirely on waste heat, a resource that is otherwise dispelled into the environment. The following research models this storage technology in several electricity spot markets around the US to determine if it is economically viable. A modification to the storage dispatch scheme is then presented which allows the storage unit to increase its profit in real-time markets by taking advantage of extreme price fluctuations. Next, the technology is modeled in combination with an industrial load profile on two different utility rate schedules to determine potential cost savings. The forecast of facility load has a significant impact on savings from the storage dispatch, so an exploration into this relationship is then presented.

  18. Preliminary survey and evaluation of nonaquifer thermal energy storage concepts for seasonal storage

    Energy Technology Data Exchange (ETDEWEB)

    Blahnik, D.E.

    1980-11-01

    Thermal energy storage enables the capture and retention of heat energy (or cold) during one time period for use during another. Seasonal thermal energy storage (STES) involves a period of months between the input and recovery of energy. The purpose of this study was to make a preliminary investigation and evaluation of potential nonaquifer STES systems. Current literature was surveyed to determine the state of the art of thermal energy storage (TES) systems such as hot water pond storage, hot rock storage, cool ice storage, and other more sophisticated concepts which might have potential for future STES programs. The main energy sources for TES principally waste heat, and the main uses of the stored thermal energy, i.e., heating, cooling, and steam generation are described. This report reviews the development of sensible, latent, and thermochemical TES technologies, presents a preliminary evaluation of the TES methods most applicable to seasonal storage uses, outlines preliminary conclusions drawn from the review of current TES literature, and recommends further research based on these conclusions. A bibliography of the nonaquifer STES literature review, and examples of 53 different TES concepts drawn from the literature are provided. (LCL)

  19. Seasonal energy storage - PV-hydrogen systems

    Energy Technology Data Exchange (ETDEWEB)

    Leppaenen, J. [Neste Oy/NAPS (Finland)

    1998-10-01

    PV systems are widely used in remote areas e.g. in telecommunication systems. Typically lead acid batteries are used as energy storage. In northern locations seasonal storage is needed, which however is too expensive and difficult to realise with batteries. Therefore, a PV- battery system with a diesel backup is sometimes used. The disadvantages of this kind of system for very remote applications are the need of maintenance and the need to supply the fuel. To overcome these problems, it has been suggested to use hydrogen technologies to make a closed loop autonomous energy storage system

  20. Solar energy thermalization and storage device

    Science.gov (United States)

    McClelland, J.F.

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

  1. Clean energy storage technology in the making: An innovation systems perspective on flywheel energy storage.

    Science.gov (United States)

    Wicki, Samuel; Hansen, Erik G

    2017-09-20

    The emergence and diffusion of green and sustainable technologies is full of obstacles and has therefore become an important area of research. We are interested in further understanding the dynamics between entrepreneurial experimentation, market formation, and institutional contexts, together playing a decisive role for successful diffusion of such technologies. Accordingly, we study these processes by adopting a technological innovation system perspective focusing on actors, networks, and institutions as well as the functions provided by them. Using a qualitative case study research design, we focus on the high-speed flywheel energy storage technology. As flywheels are based on a rotating mass allowing short-term storage of energy in kinetic form, they represent an environmentally-friendly alternative to electrochemical batteries and therefore can play an important role in sustainable energy transitions. Our contribution is threefold: First , regarding the flywheel energy storage technology, our findings reveal two subsystems and related markets in which development took different courses. In the automotive sector, flywheels are developing well as a braking energy recovery technology under the influence of two motors of innovation. In the electricity sector, they are stagnating at the stage of demonstration projects because of two important system weaknesses that counteract demand for storage. Second , we contribute to the theory of technological innovation systems by better understanding the internal dynamics between different functions of an innovation system as well as between the innovation system and its (external) contextual structures. Our third contribution is methodological. According to our best knowledge, we are the first to use system dynamics to (qualitatively) analyze and visualize dynamics between the diverse functions of innovation systems with the aim of enabling a better understanding of complex and iterative system processes. The paper also

  2. Seneca Compressed Air Energy Storage (CAES) Project

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2012-11-30

    Compressed Air Energy Storage (CAES) is a hybrid energy storage and generation concept that has many potential benefits especially in a location with increasing percentages of intermittent wind energy generation. The objectives of the NYSEG Seneca CAES Project included: for Phase 1, development of a Front End Engineering Design for a 130MW to 210 MW utility-owned facility including capital costs; project financials based on the engineering design and forecasts of energy market revenues; design of the salt cavern to be used for air storage; draft environmental permit filings; and draft NYISO interconnection filing; for Phase 2, objectives included plant construction with a target in-service date of mid-2016; and for Phase 3, objectives included commercial demonstration, testing, and two-years of performance reporting. This Final Report is presented now at the end of Phase 1 because NYSEG has concluded that the economics of the project are not favorable for development in the current economic environment in New York State. The proposed site is located in NYSEG’s service territory in the Town of Reading, New York, at the southern end of Seneca Lake, in New York State’s Finger Lakes region. The landowner of the proposed site is Inergy, a company that owns the salt solution mining facility at this property. Inergy would have developed a new air storage cavern facility to be designed for NYSEG specifically for the Seneca CAES project. A large volume, natural gas storage facility owned and operated by Inergy is also located near this site and would have provided a source of high pressure pipeline quality natural gas for use in the CAES plant. The site has an electrical take-away capability of 210 MW via two NYSEG 115 kV circuits located approximately one half mile from the plant site. Cooling tower make-up water would have been supplied from Seneca Lake. NYSEG’s engineering consultant WorleyParsons Group thoroughly evaluated three CAES designs and concluded that any

  3. Functional Carbon Materials for Electrochemical Energy Storage

    Science.gov (United States)

    Zhou, Huihui

    The ability to harvest and convert solar energy has been associated with the evolution of human civilization. The increasing consumption of fossil fuels since the industrial revolution, however, has brought to concerns in ecological deterioration and depletion of the fossil fuels. Facing these challenges, humankind is forced to seek for clean, sustainable and renewable energy resources, such as biofuels, hydraulic power, wind power, geothermal energy and other kinds of alternative energies. However, most alternative energy sources, generally in the form of electrical energy, could not be made available on a continuous basis. It is, therefore, essential to store such energy into chemical energy, which are portable and various applications. In this context, electrochemical energy-storage devices hold great promises towards this goal. The most common electrochemical energy-storage devices are electrochemical capacitors (ECs, also called supercapacitors) and batteries. In comparison to batteries, ECs posses high power density, high efficiency, long cycling life and low cost. ECs commonly utilize carbon as both (symmetric) or one of the electrodes (asymmetric), of which their performance is generally limited by the capacitance of the carbon electrodes. Therefore, developing better carbon materials with high energy density has been emerging as one the most essential challenges in the field. The primary objective of this dissertation is to design and synthesize functional carbon materials with high energy density at both aqueous and organic electrolyte systems. The energy density (E) of ECs are governed by E = CV 2/2, where C is the total capacitance and V is the voltage of the devices. Carbon electrodes with high capacitance and high working voltage should lead to high energy density. In the first part of this thesis, a new class of nanoporous carbons were synthesized for symmetric supercapacitors using aqueous Li2SO4 as the electrolyte. A unique precursor was adopted to

  4. Pumped hydro energy storage in buildings

    International Nuclear Information System (INIS)

    Oliveira e Silva, Guilherme de; Hendrick, Patrick

    2016-01-01

    Highlights: • Novel analysis of unique building with integrated pumped hydro energy storage system. • Full parameterisation of pumped hydro energy storage in buildings. • Feasibility of pumped hydro energy storage in buildings is studied. • Conditions for a better competitiveness of this technology are discussed. - Abstract: The growing use of variable energy sources is pushing the need for energy storage. With Pumped Hydro Energy Storage (PHES) representing most of the world’s energy storage installed capacity and given its maturity and simplicity, the question stands as to whether this technology could be used on a smaller scale, namely in buildings. In this paper, the feasibility of such an installation is analysed by modelling each one of its components and applying it to several installation scenarios. Proposed and existing installations are also reviewed, including a first-time analysis of an installation in France, which is presumably the only existing building with an integrated PHES system. It was found that the economies of scale that render large PHES installations competitive are not present in small installations. This limitation, associated to other important disadvantages, such as the large volume required, seem to point out PHES as an ill-suited solution for energy storage in buildings, an important finding for building design and energy policy. Nevertheless, if synergies with existing reservoirs could be found (for example for a building on a riverside), costs could be significantly lowered. Further research on possible synergies with other building systems as well as a life-cycle assessment analysis are recommended.

  5. Trigenerative micro compressed air energy storage: Concept and thermodynamic assessment

    International Nuclear Information System (INIS)

    Facci, Andrea L.; Sánchez, David; Jannelli, Elio; Ubertini, Stefano

    2015-01-01

    Highlights: • The trigenerative-CAES concept is introduced. • The thermodynamic feasibility of the trigenerative-CAES is assessed. • The effects of the relevant parameter on the system performances are dissected. • Technological issues on the trigenerative-CAES are highlighted. - Abstract: Energy storage is a cutting edge front for renewable and sustainable energy research. In fact, a massive exploitation of intermittent renewable sources, such as wind and sun, requires the introduction of effective mechanical energy storage systems. In this paper we introduce the concept of a trigenerative energy storage based on a compressed air system. The plant in study is a simplified design of the adiabatic compressed air energy storage and accumulates mechanical and thermal (both hot and cold) energy at the same time. We envisage the possibility to realize a relatively small size trigenerative compressed air energy storage to be placed close to the energy demand, according to the distributed generation paradigm. Here, we describe the plant concept and we identify all the relevant parameters influencing its thermodynamic behavior. Their effects are dissected through an accurate thermodynamic model. The most relevant technological issues, such as the guidelines for a proper choice of the compressor, expander and heat exchangers are also addressed. Our results show that T-CAES may have an interesting potential as a distributed system that combines electricity storage with heat and cooling energy production. We also show that the performances are significantly influenced by some operating and design parameters, whose feasibility in real applications must be considered.

  6. Appendix A: Energy storage technologies

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-01-18

    The project financial evaluation section of the Renewable Energy Technology Characterizations describes structures and models to support the technical and economic status of emerging renewable energy options for electricity supply.

  7. Increase of efficiency of energy output from an inductive energy storage in current multiplication circuits

    International Nuclear Information System (INIS)

    Mazulin, A.V.; Nekhaev, V.I.; Ryabtsev, G.V.; Ryazanov, K.P.; Shcherbitskij, V.N.; Yagnov, V.A.

    1984-01-01

    The power supply system for inductive load based on a sectional inductive storage, where current disbalance in storage sections at energy output is absent and efficiency of energy transfer may reach 0.71, is described. Increase of efficiency of energy transfer upto 1.0 may be obtained by using a transfer capacitor, whose power is 0.03 of that of a storage. The description of supply system operation is given and the analysis of its operation is presented. The experimental efficiency of the apparatus is 30%. The supply system may be performed on the base of toroidal inductive storage and used to supply powerful puslse systems

  8. A method to determine stratification efficiency of thermal energy storage processes independently from storage heat losses

    DEFF Research Database (Denmark)

    Haller, M.Y.; Yazdanshenas, Eshagh; Andersen, Elsa

    2010-01-01

    A new method for the calculation of a stratification efficiency of thermal energy storages based on the second law of thermodynamics is presented. The biasing influence of heat losses is studied theoretically and experimentally. Theoretically, it does not make a difference if the stratification...... directly, and a tank-in-tank system whose outer tank is charged and the inner tank is discharged thereafter. The new method has a great potential for the comparison of the stratification efficiencies of thermal energy storages and storage components such as stratifying devices....... efficiency is calculated based on entropy balances or based on exergy balances. In practice, however, exergy balances are less affected by measurement uncertainties, whereas entropy balances can not be recommended if measurement uncertainties are not corrected in a way that the energy balance of the storage...

  9. Symmetric Sodium-Ion Capacitor Based on Na0.44MnO2 Nanorods for Low-Cost and High-Performance Energy Storage.

    Science.gov (United States)

    Chen, Zhongxue; Yuan, Tianci; Pu, Xiangjun; Yang, Hanxi; Ai, Xinping; Xia, Yongyao; Cao, Yuliang

    2018-04-11

    Batteries and electrochemical capacitors play very important roles in the portable electronic devices and electric vehicles and have shown promising potential for large-scale energy storage applications. However, batteries or capacitors alone cannot meet the energy and power density requirements because rechargeable batteries have a poor power property, whereas supercapacitors offer limited capacity. Here, a novel symmetric sodium-ion capacitor (NIC) is developed based on low-cost Na 0.44 MnO 2 nanorods. The Na 0.44 MnO 2 with unique nanoarchitectures and iso-oriented feature offers shortened diffusion path lengths for both electronic and Na + transport and reduces the stress associated with Na + insertion and extraction. Benefiting from these merits, the symmetric device achieves a high power density of 2432.7 W kg -1 , an improved energy density of 27.9 Wh kg -1 , and a capacitance retention of 85.2% over 5000 cycles. Particularly, the symmetric NIC based on Na 0.44 MnO 2 permits repeatedly reverse-polarity characteristics, thus simplifying energy management system and greatly enhancing the safety under abuse condition. This cost-effective, high-safety, and high-performance symmetric NIC can balance the energy and power density between batteries and capacitors and serve as an electric power source for future low-maintenance large-scale energy storage systems.

  10. Optimization of energy storage in power systems

    International Nuclear Information System (INIS)

    Abou Chacra, F.

    2005-07-01

    For more than a century, electric transmission and distribution systems have been developed assuming that electric energy was almost impossible to store. Technical progress, new environmental requirements and electrical industry reforms now lead us to believe that storage in the future will be one of the main challenges in the development of power systems. Storage would have potential applications to deal with current technical constraints such as the system load, peak-load value, faults in parts of the system, control issues, etc. and economic ones such as upgrades deferral, renewable energy deployment, etc. In this study, energy storage is considered in two strategic locations in the French power system: HT/MT substations and wind farms. Possible applications and economic flags are formulated and appropriate optimization methods (genetic algorithms, Pareto) are used to maximize the project net present value. This optimization results in defining optimal capacities and control strategies for the energy storage system, taken from a set of storage technologies suitable for this problem, and in assessing the technical-economic impact of energy storage as a solution in power systems. (author)

  11. Kauai Island Utility Cooperative energy storage study.

    Energy Technology Data Exchange (ETDEWEB)

    Akhil, Abbas Ali; Yamane, Mike (Kauai Island Utility Cooperative, Lihu' e, HI); Murray, Aaron T.

    2009-06-01

    Sandia National Laboratories performed an assessment of the benefits of energy storage for the Kauai Island Utility Cooperative. This report documents the methodology and results of this study from a generation and production-side benefits perspective only. The KIUC energy storage study focused on the economic impact of using energy storage to shave the system peak, which reduces generator run time and consequently reduces fuel and operation and maintenance (O&M) costs. It was determined that a 16-MWh energy storage system would suit KIUC's needs, taking into account the size of the 13 individual generation units in the KIUC system and a system peak of 78 MW. The analysis shows that an energy storage system substantially reduces the run time of Units D1, D2, D3, and D5 - the four smallest and oldest diesel generators at the Port Allen generating plant. The availability of stored energy also evens the diurnal variability of the remaining generation units during the off- and on-peak periods. However, the net economic benefit is insufficient to justify a load-leveling type of energy storage system at this time. While the presence of storage helps reduce the run time of the smaller and older units, the economic dispatch changes and the largest most efficient unit in the KIUC system, the 27.5-MW steam-injected combustion turbine at Kapaia, is run for extra hours to provide the recharge energy for the storage system. The economic benefits of the storage is significantly reduced because the charging energy for the storage is derived from the same fuel source as the peak generation source it displaces. This situation would be substantially different if there were a renewable energy source available to charge the storage. Especially, if there is a wind generation resource introduced in the KIUC system, there may be a potential of capturing the load-leveling benefits as well as using the storage to dampen the dynamic instability that the wind generation could introduce

  12. Storage, a stake for renewable energies integration

    International Nuclear Information System (INIS)

    Grabette, Olivier

    2013-01-01

    Development of renewable energy sources is challenging the power system operation. Balancing consumption and generation at different times, from real time up to 10 years, with an increasing part of intermittent and fatal sources should indicate a clear route to storage development Up to now on opposite situation occurs. New storage project in Europe has been stopped because of missing business model, and there is no long term economical signal showing it could change in the near future. The capability to predict with a good accuracy, and share through the European transmission system the renewable production places storage in direct competition with other sources of flexibility. However, use case of storage is not limited to energy balancing. Ancillary services, connexion cost optimization, quality of supply are among other possible services offered by storage installation. For all of those, understanding technical requirements and economical issues is an initial condition to open a favourable game area for storage. Exploring new multi-service models through demonstrators, redesigning the electricity market in Europe are key initiatives to approach a new era for storage development. It doesn't prevent innovation to improve performance and reduce cost, an essential condition to give a chance for storage solution compared to other flexibility sources. (author)

  13. Energy storage systems cost update : a study for the DOE Energy Storage Systems Program.

    Energy Technology Data Exchange (ETDEWEB)

    Schoenung, Susan M. (Longitude 122 West, Menlo Park, CA)

    2011-04-01

    This paper reports the methodology for calculating present worth of system and operating costs for a number of energy storage technologies for representative electric utility applications. The values are an update from earlier reports, categorized by application use parameters. This work presents an update of energy storage system costs assessed previously and separately by the U.S. Department of Energy (DOE) Energy Storage Systems Program. The primary objective of the series of studies has been to express electricity storage benefits and costs using consistent assumptions, so that helpful benefit/cost comparisons can be made. Costs of energy storage systems depend not only on the type of technology, but also on the planned operation and especially the hours of storage needed. Calculating the present worth of life-cycle costs makes it possible to compare benefit values estimated on the same basis.

  14. Peak reduction for commercial buildings using energy storage

    Science.gov (United States)

    Chua, K. H.; Lim, Y. S.; Morris, S.

    2017-11-01

    Battery-based energy storage has emerged as a cost-effective solution for peak reduction due to the decrement of battery’s price. In this study, a battery-based energy storage system is developed and implemented to achieve an optimal peak reduction for commercial customers with the limited energy capacity of the energy storage. The energy storage system is formed by three bi-directional power converter rated at 5 kVA and a battery bank with capacity of 64 kWh. Three control algorithms, namely fixed-threshold, adaptive-threshold, and fuzzy-based control algorithms have been developed and implemented into the energy storage system in a campus building. The control algorithms are evaluated and compared under different load conditions. The overall experimental results show that the fuzzy-based controller is the most effective algorithm among the three controllers in peak reduction. The fuzzy-based control algorithm is capable of incorporating a priori qualitative knowledge and expertise about the load characteristic of the buildings as well as the useable energy without over-discharging the batteries.

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

    Science.gov (United States)

    Luo, Bin; Ye, Delai; Wang, Lianzhou

    2017-09-01

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

  16. Environmental/Economic Operation Management of a Renewable Microgrid with Wind/PV/FC/MT and Battery Energy Storage Based on MSFLA

    Directory of Open Access Journals (Sweden)

    Morteza Haghshenas

    2016-03-01

    Full Text Available Microgrids (MGs are local grids consisting of Distributed generators, energy storage systems and dispersed loads which may operate in both grid-connected and islanded modes. This paper aims to optimize the operation of a typical grid-connected MG which comprises a variety of DGs and storage devices in order to minimize both total operation cost and environmental impacts resulted from supplying local demands. Furthermore we will try to achieve an intelligent schedule to charge and discharge storage devices that provides the opportunity to benefit from market price fluctuations. The presented optimization framework is based on multiobjective modified shuffled frog leaping algorithm (MSFLA. To solve environmental/economic operation management (EEOM problem using MSFLA, a new frog leaping rule, associated with a new strategy for frog distribution into memeplexes, is proposed to improve the local exploration and performance of the ordinary shuffled frog leaping algorithm. The proposed method is examined and tested on a grid-connected MG including fuel cell, wind turbine, photovoltaic, gas-fired microturbine, and battery energy storage devices. The simulation results for three scenarios involving the economic operation management of MG, environmental operation management of MG, and environmental/economic operation management of MG are presented separately. The obtained results compared with results of well-known methods reported in the literature and prove the efficiency of the proposed approach to solve the both single objective and multiobjective operation management of the MG.

  17. Storage and transmission of secondary energy

    International Nuclear Information System (INIS)

    Taube, M.

    1979-09-01

    In the area of the total energy flow, possibilities and limits of shifts in time (storage) and in space (transfer) of secondary energy, i.e. electrical, chemical and thermal energy are examined and formulated. These shifts are linked to the qualitative conversions of secondary energy. The multiple technological possibilities, the spectrum of governing factors and the numerous technical and economical parameters show that only a complex optimization is possible. (Auth.)

  18. Optimal Active Power Control of A Wind Farm Equipped with Energy Storage System based on Distributed Model Predictive Control

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Guo, Qinglai

    2016-01-01

    This paper presents the Distributed Model Predictive Control (D-MPC) of a wind farm equipped with fast and short-term Energy Storage System (ESS) for optimal active power control using the fast gradient method via dual decomposition. The primary objective of the D-MPC control of the wind farm...... is power reference tracking from system operators. Besides, by optimal distribution of the power references to individual wind turbines and the ESS unit, the wind turbine mechanical loads are alleviated. With the fast gradient method, the convergence rate of the DMPC is significantly improved which leads...... to a reduction of the iteration number. Accordingly, the communication burden is reduced. Case studies demonstrate that the additional ESS unit can lead to a larger wind turbine load reduction, compared to the conventional wind farm control without ESS. Moreover, the efficiency of the developed D-MPC algorithm...

  19. Multifunctional Composites for Future Energy Storage in Aerospace Structures

    Directory of Open Access Journals (Sweden)

    Till Julian Adam

    2018-02-01

    Full Text Available Multifunctionalization of fiber-reinforced composites, especially by adding energy storage capabilities, is a promising approach to realize lightweight structural energy storages for future transport vehicles. Compared to conventional energy storage systems, energy density can be increased by reducing parasitic masses of non-energy-storing components and by benefitting from the composite meso- and microarchitectures. In this paper, the most relevant existing approaches towards multifunctional energy storages are reviewed and subdivided into five groups by distinguishing their degree of integration and their scale of multifunctionalization. By introducing a modified range equation for battery-powered electric aircrafts, possible range extensions enabled by multifunctionalization are estimated. Furthermore, general and aerospace specific potentials of multifunctional energy storages are discussed. Representing an intermediate degree of structural integration, experimental results for a multifunctional energy-storing glass fiber-reinforced composite based on the ceramic electrolyte Li1.4Al0.4Ti1.6(PO43 are presented. Cyclic voltammetry tests are used to characterize the double-layer behavior combined with galvanostatic charge–discharge measurements for capacitance calculation. The capacitance is observed to be unchanged after 1500 charge–discharge cycles revealing a promising potential for future applications. Furthermore, the mechanical properties are assessed by means of four-point bending and tensile tests. Additionally, the influence of mechanical loads on the electrical properties is also investigated, demonstrating the storage stability of the composites.

  20. Hydrogen-based energy storage unit for stand alone PV systems; L'hydrogene electrolytique comme moyen de stockage d'electricite pour systemes photovoltaiques isoles

    Energy Technology Data Exchange (ETDEWEB)

    Labbe, J

    2006-12-15

    Stand alone systems supplied only by a photovoltaic generator need an energy storage unit to be fully self sufficient. Lead acid batteries are commonly used to store energy because of their low cost, despite several operational constraints. A hydrogen-based energy storage unit (HESU) could be another candidate, including an electrolyser, a fuel cell and a hydrogen tank. However many efforts still need to be carried out for this technology to reach an industrial stage. In particular, market outlets must be clearly identified. The study of small stationary applications (few kW) is performed by numerical simulations. A simulator is developed in the Matlab/Simulink environment. It is mainly composed of a photovoltaic field and a storage unit (lead acid batteries, HESU, or hybrid storage HESU/batteries). The system component sizing is achieved in order to ensure the complete system autonomy over a whole year of operation. The simulator is tested with 160 load profiles (1 kW as a yearly mean value) and three locations (Algeria, France and Norway). Two coefficients are set in order to quantify the correlation between the power consumption of the end user and the renewable resource availability at both daily and yearly scales. Among the tested cases, a limit value of the yearly correlation coefficient came out, enabling to recommend the use of the most adapted storage to a considered case. There are cases for which using HESU instead of lead acid batteries can increase the system efficiency, decrease the size of the photovoltaic field and improve the exploitation of the renewable resource. In addition, hybridization of HESU with batteries always leads to system enhancements regarding its sizing and performance, with an efficiency increase by 10 to 40 % depending on the considered location. The good agreement between the simulation data and field data gathered on real systems enabled the validation of the models used in this study. (author)

  1. High yield fabrication of hollow vesica-like silicon based on the Kirkendall effect and its application to energy storage.

    Science.gov (United States)

    Liang, Jianwen; Li, Xiaona; Cheng, Qiushi; Hou, Zhiguo; Fan, Long; Zhu, Yongchun; Qian, Yitai

    2015-02-28

    Recently, a unique process based on the Kirkendall effect was employed to generate hollow nanostructures with a wide variety of materials. However, a similar hollow structure of silicon based on the fabrication mechanism of the Kirkendall effect is still not proposed. Here, we provide an extensible synthesis method for the high yield fabrication of a uniform vesica-like hollow Si material from SiO2 based on the Kirkendall effect in a molten salt reduction process. Significantly, without further modification, the as-prepared hollow vesica-like Si exhibits a high electrochemical storage capacity and long cycling properties (∼712 mA h g(-1) at 0.36 A g(-1) over 200 cycles).

  2. Global distribution of grid connected electrical energy storage systems

    Directory of Open Access Journals (Sweden)

    Katja Buss

    2016-06-01

    Full Text Available This article gives an overview of grid connected electrical energy storage systems worldwide, based on public available data. Technologies considered in this study are pumped hydroelectric energy storage (PHES, compressed air energy storage (CAES, sodium-sulfur batteries (NaS, lead-acid batteries, redox-flow batteries, nickel-cadmium batteries (NiCd and lithium-ion batteries. As the research indicates, the worldwide installed capacity of grid connected electrical energy storage systems is approximately 154 GW. This corresponds to a share of 5.5 % of the worldwide installed generation capacity. Furthermore, the article gives an overview of the historical development of installed and used storage systems worldwide. Subsequently, the focus is on each considered technology concerning the current storage size, number of plants and location. In summary it can be stated, PHES is the most commonly used technology worldwide, whereas electrochemical technologies are increasingly gaining in importance. Regarding the distribution of grid connected storage systems reveals the share of installed storage capacity is in Europe and Eastern Asia twice as high as in North America.

  3. Energy Storage Fuel Cell Vehicle Analysis: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Markel, T.; Pesaran, A.; Zolot, M.; Sprik, S.; Tataria, H.; Duong, T.

    2005-04-01

    In recent years, hydrogen fuel cell (FC) vehicle technology has received considerable attention as a strategy to decrease oil consumption and reduce harmful emissions. However, the cost, transient response, and cold performance of FC systems may present significant challenges to widespread adoption of the technology for transportation in the next 15 years. The objectives of this effort were to perform energy storage modeling with fuel cell vehicle simulations to quantify the benefits of hybridization and to identify a process for setting the requirements of ES for hydrogen-powered FC vehicles for U.S. Department of Energy's Energy Storage Program.

  4. 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

  5. High energy density, long life energy storage capacitor dielectric system

    International Nuclear Information System (INIS)

    Nichols, D.H.; Wilson, S.R.

    1977-01-01

    The evolution of energy storage dielectric systems shows a dramatic improvement in life and joule density, culminating in a 50% to 300% life improvement of polypropylene film-paper-phthalate ester over paper-castor oil depending on service. The physical and electrical drawbacks of castor oil are not present in the new system, allowing the capacitor designer to utilize the superior insulation resistance, dielectric strength, and corona resistance to full advantage. The result is longer life for equal joule density or greater joule density for equal life. Field service proof of the film-Geconol system superiority is based on 5 megajoule in operation and 16 megajoule on order

  6. Energy and Exergy Analysis of Ocean Compressed Air Energy Storage Concepts

    Directory of Open Access Journals (Sweden)

    Vikram C. Patil

    2018-01-01

    Full Text Available Optimal utilization of renewable energy resources needs energy storage capability in integration with the electric grid. Ocean compressed air energy storage (OCAES can provide promising large-scale energy storage. In OCAES, energy is stored in the form of compressed air under the ocean. Underwater energy storage results in a constant-pressure storage system which has potential to show high efficiency compared to constant-volume energy storage. Various OCAES concepts, namely, diabatic, adiabatic, and isothermal OCAES, are possible based on the handling of heat in the system. These OCAES concepts are assessed using energy and exergy analysis in this paper. Roundtrip efficiency of liquid piston based OCAES is also investigated using an experimental liquid piston compressor. Further, the potential of improved efficiency of liquid piston based OCAES with use of various heat transfer enhancement techniques is investigated. Results show that adiabatic OCAES shows improved efficiency over diabatic OCAES by storing thermal exergy in thermal energy storage and isothermal OCAES shows significantly higher efficiency over adiabatic and diabatic OCAES. Liquid piston based OCAES is estimated to show roundtrip efficiency of about 45% and use of heat transfer enhancement in liquid piston has potential to improve roundtrip efficiency of liquid piston based OCAES up to 62%.

  7. Energy Storage Applications in Power Systems with Renewable Energy Generation

    Science.gov (United States)

    Ghofrani, Mahmoud

    In this dissertation, we propose new operational and planning methodologies for power systems with renewable energy sources. A probabilistic optimal power flow (POPF) is developed to model wind power variations and evaluate the power system operation with intermittent renewable energy generation. The methodology is used to calculate the operating and ramping reserves that are required to compensate for power system uncertainties. Distributed wind generation is introduced as an operational scheme to take advantage of the spatial diversity of renewable energy resources and reduce wind power fluctuations using low or uncorrelated wind farms. The POPF is demonstrated using the IEEE 24-bus system where the proposed operational scheme reduces the operating and ramping reserve requirements and operation and congestion cost of the system as compared to operational practices available in the literature. A stochastic operational-planning framework is also proposed to adequately size, optimally place and schedule storage units within power systems with high wind penetrations. The method is used for different applications of energy storage systems for renewable energy integration. These applications include market-based opportunities such as renewable energy time-shift, renewable capacity firming, and transmission and distribution upgrade deferral in the form of revenue or reduced cost and storage-related societal benefits such as integration of more renewables, reduced emissions and improved utilization of grid assets. A power-pool model which incorporates the one-sided auction market into POPF is developed. The model considers storage units as market participants submitting hourly price bids in the form of marginal costs. This provides an accurate market-clearing process as compared to the 'price-taker' analysis available in the literature where the effects of large-scale storage units on the market-clearing prices are neglected. Different case studies are provided to

  8. Energy storage in future power systems

    DEFF Research Database (Denmark)

    Rasmussen, Claus Nygaard; Østergaard, Jacob; Divya, K. C.

    2011-01-01

    conventional generation form being used. In addition to this, one of the strongest concerns in relation to renewable power is the instability in the electric power system that it may introduce as a result of large and relatively fast power fluctuations. An additional benefit of energy storage is therefore its......Most sources of renewable power are characterised by uncontrollable and chaotic variations in power output. We here look at how energy storage may benefit renewable power generation by making it available in periods with little or no intermittent generation and thereby prevent additional....... When identifying the most relevant storage solutions it is necessary to include considerations on many relevant parameters which should be evaluated against the potential drawbacks and benefits of adding storage. Here, the most relevant technologies in relation to power systems with high penetration...

  9. Technoeconomic Modeling of Battery Energy Storage in SAM

    Energy Technology Data Exchange (ETDEWEB)

    DiOrio, Nicholas [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dobos, Aron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Janzou, Steven [National Renewable Energy Lab. (NREL), Golden, CO (United States); Nelson, Austin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lundstrom, Blake [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    Detailed comprehensive lead-acid and lithium-ion battery models have been integrated with photovoltaic models in an effort to allow System Advisor Model (SAM) to offer the ability to predict the performance and economic benefit of behind the meter storage. In a system with storage, excess PV energy can be saved until later in the day when PV production has fallen, or until times of peak demand when it is more valuable. Complex dispatch strategies can be developed to leverage storage to reduce energy consumption or power demand based on the utility rate structure. This document describes the details of the battery performance and economic models in SAM.

  10. Special file on the storage of energies

    International Nuclear Information System (INIS)

    Signoret, Stephane; Kim, Caroline; Bohlinger, Philippe; Petitot, Pauline; Mary, Olivier; Guilhem, Jean

    2017-01-01

    After brief presentations of current research and industrial activities, a first article comments the new impetus of storage technologies and projects due to regulatory and legal evolutions associated with the French law on energy transition. Self-consumption and flexibility systems in distribution networks are practical factors of this evolution. Benefits provided by energy storage are notably outlined. The next articles present several examples: a decentralised heat storage in Brest, a flywheel plant by Levisys. An article then discusses the technological and commercial aspects of the battle in this sector for the French majors (EDF, Engie, Total). An article comments the emergence and development of a range of solutions for energy storage in case of self-consumption. The next article briefly presents the Elsa project (financed by the EU) which gives a second life to electric vehicle batteries by developing an energy storage and control solution for professionals. A system developed by French researchers is briefly presented: it aims at producing electricity, at storing it, and at using it to supply isolated autonomous systems. The idea developed in a published study is then discussed: to use electric vehicle batteries to store the intermittent energy produced by renewable sources. The last article comments the integration by Enedis of intelligent devices into the grid

  11. An energy storage and regeneration system

    DEFF Research Database (Denmark)

    2006-01-01

      The present invention relates to a method and a system for storing excess energy produced by an electric power plant during periods of lower energy demand than the power plant production capacity. The excess energy is stored by hydrolysis of water and storage of hydrogen and oxygen in underground...... caverns. When the energy demand exceeds the power production capacity of the plant, the stored gases are burned and the thermal energy is converted into electricity in gas turbine generators. The regenerated electrical power is then used to supplement the output of the electric power plant to meet...... the higher level of energy demand....

  12. Chemistry of energy conversion and storage.

    Science.gov (United States)

    Su, Dang Sheng

    2012-03-12

    Energy is a big issue in our society, fueled by growing awareness of the finite resources of liquid fossil fuels and the noticeable changes in our climate resulting from its consumption. The general consensus is that there should be a well-considered roadmap towards a future energy scenario, with the replacement of fossil energy by renewable energies as the final goal. This "Chemistry of Energy Conversion and Storage" issue contains papers dealing with the chemistry behind renewable energies. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Energy storage for improvement of wind power characteristics

    OpenAIRE

    Rasmussen, Claus Nygaard

    2011-01-01

    Results from simulation of the influence of energy storage on the variability and availability of wind energy are presented here. Simulations have been done using a mathematical model of energy storage implemented in MATLAB. The obtained results show the quality improvement, of energy delivered by a combination of wind and energy storage, in relation to the size of the energy storage. The introduction of storage enables suppression of wind power fluctuations up to a timescale proportional to ...

  14. 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. [...

  15. Energy Scheduling of Battery Storage Systems in Micro Grids

    Directory of Open Access Journals (Sweden)

    Armstorfer Andreas

    2017-07-01

    Full Text Available Microgrids in island mode with high penetration of renewable energy sources in combination with gensets and battery storage systems need a control system for voltage and frequency. In this study the main goal is maximization of the energy feed-in by renewable sources. Therefore it is necessary to keep the State of Energy for the Battery Storage System in a range that the excess energy can be absorbed and used in a later period of the day. In this paper an approach for State of Charge scheduling based on load and generation prediction is described.

  16. An Economic Evalution of Demand-side Energy Storage Systems by using a Multi-agent based Electricity Market

    Science.gov (United States)

    Furusawa, Ken; Sugihara, Hideharu; Tsuji, Kiichiro

    Opened wholesale electric power market in April 2005, deregulation of electric power industry in Japan has faced a new competitive environment. In the new environment, Independent Power Producer (: IPP), Power Producer and Supplier (: PPS), Load Service Entity (: LSE) and electric utility can trade electric energy through both bilateral contracts and single-price auction at the electricity market. In general, the market clearing price (: MCP) is largely changed by amount of total load demand in the market. The influence may cause price spike, and consequently the volatility of MCP will make LSEs and their customers to face a risk of revenue and cost. DSM is attracted as a means of load leveling, and has effect on decreasing MCP at peak load period. Introducing Energy Storage systems (: ES) is one of DSM in order to change demand profile at customer-side. In case that customers decrease their own demand at jumped MCP, a bidding strategy of generating companies may be changed their strategy. As a result, MCP is changed through such complex mechanism. In this paper the authors evaluate MCP by multi-agent. It is considered that customer-side ES has an effect on MCP fluctuation. Through numerical examples, this paper evaluates the influence on MCP by controlling customer-side ES corresponding to variation of MCP.

  17. Economic models for battery energy storage

    International Nuclear Information System (INIS)

    Reckrodt, R.C.; Anderson, M.D.; Kluczny, R.M.

    1990-01-01

    While the technology required to produce viable Battery Energy Storage System exists, the economic feasibility (cost vs. benefits) of building these systems requires justification. First, a generalized decision diagram was developed to ensure that all of the economic factors were considered and properly related for the customer-side-of-the meter. Next, two economic models that had consistently given differing results were compared. One was the McKinney model developed at UM-Rolla in 1987; the second was the SYSPLAN model developed by Battelle. Differences were resolved on a point by point basis with reference to the current economic environment. The economic model was upgraded to include the best of both models based on the resolution of these differences. The upgrades were implemented as modifications to the original SYSPLAN (1986 version) to preserve user friendliness. In this paper four specific cases are evaluated and compared. The results are as predicted, since comparison was made with two known models

  18. A stochastic self-scheduling program for compressed air energy storage (CAES) of renewable energy sources (RESs) based on a demand response mechanism

    International Nuclear Information System (INIS)

    Ghalelou, Afshin Najafi; Fakhri, Alireza Pashaei; Nojavan, Sayyad; Majidi, Majid; Hatami, Hojat

    2016-01-01

    Highlights: • Optimal stochastic energy management of renewable energy sources (RESs) is proposed. • The compressed air energy storage (CAES) besides RESs is used in the presence of DRP. • Determination charge and discharge of CAES in order to reduce the expected operation cost. • Moreover, demand response program (DRP) is proposed to minimize the operation cost. • The uncertainty modeling of input data are considered in the proposed stochastic framework. - Abstract: In this paper, a stochastic self-scheduling of renewable energy sources (RESs) considering compressed air energy storage (CAES) in the presence of a demand response program (DRP) is proposed. RESs include wind turbine (WT) and photovoltaic (PV) system. Other energy sources are thermal units and CAES. The time-of-use (TOU) rate of DRP is considered in this paper. This DRP shifts the percentage of load from the expensive period to the cheap one in order to flatten the load curve and minimize the operation cost, consequently. The proposed objective function includes minimizing the operation costs of thermal unit and CAES, considering technical and physical constraints. The proposed model is formulated as mixed integer linear programming (MILP) and it is been solved using General Algebraic Modeling System (GAMS) optimization package. Furthermore, CAES and DRP are incorporated in the stochastic self-scheduling problem by a decision maker to reduce the expected operation cost. Meanwhile, the uncertainty models of market price, load, wind speed, temperature and irradiance are considered in the formulation. Finally, to assess the effects of DRP and CAES on self-scheduling problem, four case studies are utilized, and significant results were obtained, which indicate the validity of the proposed stochastic program.

  19. Enhanced performance and interfacial investigation of mineral-based composite phase change materials for thermal energy storage.

    Science.gov (United States)

    Li, Chuanchang; Fu, Liangjie; Ouyang, Jing; Yang, Huaming

    2013-01-01

    A novel mineral-based composite phase change materials (PCMs) was prepared via vacuum impregnation method assisted with microwave-acid treatment of the graphite (G) and bentonite (B) mixture. Graphite and microwave-acid treated bentonite mixture (GBm) had more loading capacity and higher crystallinity of stearic acid (SA) in the SA/GBm composite. The SA/GBm composite showed an enhanced thermal storage capacity, latent heats for melting and freezing (84.64 and 84.14 J/g) was higher than those of SA/B sample (48.43 and 47.13 J/g, respectively). Addition of graphite was beneficial to the enhancement in thermal conductivity of the SA/GBm composite, which could reach 0.77 W/m K, 31% higher than SA/B and 196% than pure SA. Furthermore, atomic-level interfaces between SA and support surfaces were depicted, and the mechanism of enhanced thermal storage properties was in detail investigated.

  20. State of Charge Balancing Control of a Multi-Functional Battery Energy Storage System Based on a 11-Level Cascaded Multilevel PWM Converter

    DEFF Research Database (Denmark)

    Wang, Songcen; Teodorescu, Remus; Máthé, Lászlo

    2015-01-01

    This paper focuses on modeling and SOC (State of Charge) balancing control of lithium-ion battery energy storage system based on cascaded multilevel converter for both grid integration and electric vehicle propulsion applications. The equivalent electrical circuit model of lithium-ion battery...... module is established based on the relationship between SOC (State of Charge) and OCV (Open Circuit Voltage) which is obtained from the battery charge and discharge test curves. A hierarchical control structure is proposed to realize different operating modes. The decoupled current control scheme...

  1. Composite materials for thermal energy storage

    Science.gov (United States)

    Benson, D.K.; Burrows, R.W.; Shinton, Y.D.

    1985-01-04

    A composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations. These PCM's do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

  2. Energy Storage Requirements & Challenges for Ground Vehicles

    Science.gov (United States)

    2010-03-18

    provide electric power to start the vehicle power generation (Engines / APUs)  Hybrid Vehicle Boost Acceleration and Regenerative Braking Energy Capture...Cooling Thermal Architectures Po we r Ma na ge m en t Power Controllers for Power Management Power Converters/ Inverters Wide Band Gap Materials (SiC...to recover wasted energy in vehicle braking  Silent Watch Batteries can provide the energy storage capability to power mission equipment with

  3. Effect of nanoparticles on heat capacity of nanofluids based on molten salts as PCM for thermal energy storage.

    Science.gov (United States)

    Chieruzzi, Manila; Cerritelli, Gian F; Miliozzi, Adio; Kenny, José M

    2013-10-29

    In this study, different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (selected as phase change material) with nanoparticles using the direct-synthesis method. The thermal properties of the nanofluids obtained were investigated. These nanofluids can be used in concentrating solar plants with a reduction of storage material if an improvement in the specific heat is achieved. The base salt mixture was a NaNO3-KNO3 (60:40 ratio) binary salt. The nanoparticles used were silica (SiO2), alumina (Al2O3), titania (TiO2), and a mix of silica-alumina (SiO2-Al2O3). Three weight fractions were evaluated: 0.5, 1.0, and 1.5 wt.%. Each nanofluid was prepared in water solution, sonicated, and evaporated. Measurements on thermophysical properties were performed by differential scanning calorimetry analysis and the dispersion of the nanoparticles was analyzed by scanning electron microscopy (SEM). The results obtained show that the addition of 1.0 wt.% of nanoparticles to the base salt increases the specific heat of 15% to 57% in the solid phase and of 1% to 22% in the liquid phase. In particular, this research shows that the addition of silica-alumina nanoparticles has a significant potential for enhancing the thermal storage characteristics of the NaNO3-KNO3 binary salt. These results deviated from the predictions of the theoretical model used. SEM suggests a greater interaction between these nanoparticles and the salt.

  4. Energy storage system using superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Joong; Kim, Ki Baek; Park, Hae Woong; Hong, Kye Won [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-03-01

    As a result of continuous efforts, high critical current density exceeding 104 A/cm{sup 2} at 77K and strong levitation capacity has been achieved in Y-Ba-Cu-O superconductor which is fabricated by melting technique. Various applications using the levitation properties of high-Tc superconductor is expected to come true in near future. Especially, by utilizing the levitation force between a permanent magnet and the superconductor, a flywheel system which store electrical energy as mechanical energy can be designed. (Author) 11 refs., 7 figs., 5 tabs.

  5. Pseudocapacitive oxide materials for high-rate electrochemical energy storage

    OpenAIRE

    Augustyn, Veronica; Simon, Patrice; Dunn, Bruce

    2014-01-01

    International audience; Electrochemical energy storage technology is based on devices capable of exhibiting high energy density (batteries) or high power density (electrochemical capacitors). There is a growing need, for current andnear-future applications, where both high energy and high power densities are required in the same material. Pseudocapacitance, a faradaic process involving surface or near surface redox reactions, offers a means of achieving high energy density at high charge–disc...

  6. TRADE-OFF BETWEEN CARBON STORAGE AND BIOMASS-BASED ENERGY SOURCES ECOSYSTEM SERVICES, THE CASE STUDY FROM THE PROVINCE OF ROVIGO (ITALY

    Directory of Open Access Journals (Sweden)

    E. Gissi

    2014-04-01

    Full Text Available Biomass Based Energy Sources (BBES are an Ecosystem Service (ES which can contribute to achieve EU 2020 targets and to ensure energy security. Their effects on other ESs can be different according to biomass typologies, as energy crops and residuals. In order to plan a Greenhouse Gasses (GHGs efficient supply chain and to maintain ES of carbon storage, as well as other related ESs, effect of feedstock chain on Soil Organic Carbon (SOC should be considered. An ESs approach, based on the cascade model, takes into consideration biological interdependencies and management options to assess trade-offs. This study aims to describe and map trade-off between BBES and carbon storage services in Province of Rovigo (Veneto Region, Italy, a mainly intensive cultivated area. Results show that the trade-offs  between the two ESs is potentially high in large part of the territory (75%, while just 25% expresses low possibility of conflict. Possible management options are discussed in order to minimize trade-off between energy provision and climate change mitigation. This study highlights that ESs approach can provide a suitable tool for decision makers, with respect to biomass feedstock chain, whose effects on ecosystems are often underestimated.

  7. The economics of energy storage in 14 deregulated power markets

    International Nuclear Information System (INIS)

    Figueiredo, F.C.; Flynn, P.C.; Cabral, E.A.

    2006-01-01

    In regulated power markets, electricity is stored to better utilize existing generation and to defer costly investment in generation. The justification is a reduction in the overall regulated price of power compared to the alternative investment in new primary generation. However, any storage of electrical power also involves a capital investment and incurs the cost of inefficiency. In deregulated energy markets, the sale of electricity or ancillary services from pumped storage can be evaluated based on each individual project. The economic basis for power storage is that power is purchased during periods of low price and resold during periods of high price. This study used historical power price data from 14 deregulated markets around the world to evaluate the economic incentive to use pumped storage for electrical energy. Each market was shown to have a unique average diurnal power price profile that results in a unique price spread for pumped storage. The diurnal price pattern and efficiency of storage was used to assess the net income potential from energy sales from pumped storage for each market. The markets were ranked in terms of the incentive to invest in pumped energy storage as well as on available revenue, and on potential return on investment. An optimal operating profile was illustrated in detail based on historical price patterns for one of the markets. The net income potential was then combined with the capital and operating cost of pumped storage. The adequacy of return on investment for pumped storage was analyzed by two different methods. The differences between markets stem from different diurnal power price patterns that reflect the generation mix, market design and participant behaviours. 17 refs., 7 tabs., 7 figs., 1 appendix

  8. The Value of Energy Storage for Grid Applications

    Energy Technology Data Exchange (ETDEWEB)

    Denholm, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jorgenson, Jennie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hummon, Marissa [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jenkin, Thomas [National Renewable Energy Lab. (NREL), Golden, CO (United States); Palchak, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kirby, Brendan [Kirby Consultant; Ma, Ookie [U.S. Department of Energy, Washington, DC (United States); O' Malley, Mark [Univ. College of Dublin (Ireland)

    2013-05-01

    This analysis evaluates several operational benefits of electricity storage, including load-leveling, spinning contingency reserves, and regulation reserves. Storage devices were simulated in a utility system in the western United States, and the operational costs of generation was compared to the same system without the added storage. This operational value of storage was estimated for devices of various sizes, providing different services, and with several sensitivities to fuel price and other factors. Overall, the results followed previous analyses that demonstrate relatively low value for load-leveling but greater value for provision of reserve services. The value was estimated by taking the difference in operational costs between cases with and without energy storage and represents the operational cost savings from deploying storage by a traditional vertically integrated utility. The analysis also estimated the potential revenues derived from a merchant storage plant in a restructured market, based on marginal system prices. Due to suppression of on-/off-peak price differentials and incomplete capture of system benefits (such as the cost of power plant starts), the revenue obtained by storage in a market setting appears to be substantially less than the net benefit provided to the system. This demonstrates some of the additional challenges for storage deployed in restructured energy markets.

  9. COSTS OF THERMAL ENERGY STORAGE TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Debrayan Bravo Hidalgo

    2017-10-01

    Full Text Available Thermal accumulation facilities allow energy to be available in the absence of sunlight. This fact reduces the difficulty of the intermittence in the incidence of the king star in our planet. Thermal accumulation technology also contributes to smooth the fluctuations in energy demand during different times of the day. This contribution identifies the nations with the most favorable research results in this area; as well as the main research lines that are being developed today. A compendium of various thermal energy storage materials, their current costs per unit mass, and their physical properties are presented. Techniques for implementing thermal accumulation technologies can be classified as areas of high, medium and low temperature. In the high temperature area, inorganic materials such as nitrate salts are the most widely used thermal energy storage materials, while in the medium and lower temperature areas; organic materials such as commercial paraffin are more common. Currently, one of the research trends in this area are the projects aimed at optimizing the chemical and physical characteristics of thermal storage materials, because the success of any thermos-energetic storage technology has a strong dependence on the cost of the materials selected for thermal storage.

  10. Engineered nanomembranes for smart energy storage devices.

    Science.gov (United States)

    Wang, Xianfu; Chen, Yu; Schmidt, Oliver G; Yan, Chenglin

    2016-03-07

    Engineered nanomembranes are of great interest not only for large-scale energy storage devices, but also for on-chip energy storage integrated microdevices (such as microbatteries, microsupercapacitors, on-chip capacitors, etc.) because of their large active surfaces for electrochemical reactions, shortened paths for fast ion diffusion, and easy engineering for microdevice applications. In addition, engineered nanomembranes provide a lab-on-chip electrochemical device platform for probing the correlations of electrode structure, electrical/ionic conductivity, and electrochemical kinetics with device performance. This review focuses on the recent progress in engineered nanomembranes including tubular nanomembranes and planar nanomembranes, with the aim to provide a systematic summary of their fabrication, modification, and energy storage applications in lithium-ion batteries, lithium-oxygen batteries, on-chip electrostatic capacitors and micro-supercapacitors. A comprehensive understanding of the relationship between engineered nanomembranes and electrochemical properties of lithium ion storage with engineered single-tube microbatteries is given, and the flexibility and transparency of micro-supercapacitors is also discussed. Remarks on challenges and perspectives related to engineered nanomembranes for the further development of energy storage applications conclude this review.

  11. Workload-Based Configuration of MEMS-Based Storage Devices for Mobile Systems

    NARCIS (Netherlands)

    Khatib, M.G.; Miller, E.L.; Hartel, Pieter H.

    2008-01-01

    Because of its small form factor, high capacity, and expected low cost, MEMS-based storage is a suitable storage technology for mobile systems. However, flash memory may outperform MEMS-based storage in terms of performance, and energy-efficiency. The problem is that MEMS-based storage devices have

  12. Numerical investigation of a joint approach to thermal energy storage and compressed air storage in aquifers

    OpenAIRE

    Guo, Chaobin.; Zhanga, Keni.; Pan, Lehua.; Cai, Zuansi.; Lid, Cai.; Lie, Yi.

    2017-01-01

    Different from conventional compressed air energy storage (CAES) systems, the advanced adiabatic compressed air energy storage (AA-CAES) system can store the compression heat which can be used to reheat air during the electricity generation stage. Thus, AA-CAES system can achieve a higher energy storage efficiency. Similar to the AA-CAES system, a compressed air energy storage in aquifers (CAESA) system, which is integrated with an aquifer thermal energy storage (ATES) could possibly achieve ...

  13. Regulatory Policy and Markets for Energy Storage in North America

    Energy Technology Data Exchange (ETDEWEB)

    Kintner-Meyer, Michael CW

    2014-05-14

    The last 5 years have been one of the most exciting times for the energy storage industry. We have seen significant advancements in the regulatory process to make accommodations for valuing and monetizing energy storage for what it provides to the grid. The most impactful regulatory decision for the energy storage industry has come from California, where the California Public Utilities Commission issued a decision that mandates procurement requirements of 1.325 GW for energy storage to 3 investor-own utilities in 4 stages: in 2014, 2016, 2018, and 2020. Furthermore, at the Federal level, FERC’s Order 755, requires the transmission operators to develop pay for performance tariffs for ancillary services. This has had direct impact on the market design of US competitive wholesale markets and the monetization of fast responding grid assets. While this order is technology neutral, it clearly plays into the fast-responding capability of energy storage technologies. Today PJM, CAISO, MISO, NYISO, and NE-ISO have implemented Order 755 and offer new tariff for regulation services based on pay-for-performance principles. Furthermore, FERC Order 784, issued in July 2013 requires transmission providers to consider speed and accuracy in determining the requirements for ancillary services. In November 2013, FERC issued Order 972, which revises the small generator interconnection agreement which declares energy storage as a power source. This order puts energy storage on par with existing generators. This paper will discuss the implementation of FERC’s Pay for Performance Regulation order at all ISOs in the U.S. under FERC regulatory authority (this excludes ERCOT). Also discussed will be the market impacts and overall impacts on the NERC regulation performance indexes. The paper will end with a discussion on the California and Ontario, Canada procurement mandates and the opportunity that it may present to the energy storage industry.

  14. Twelve Principles for Green Energy Storage in Grid Applications.

    Science.gov (United States)

    Arbabzadeh, Maryam; Johnson, Jeremiah X; Keoleian, Gregory A; Rasmussen, Paul G; Thompson, Levi T

    2016-01-19

    The introduction of energy storage technologies to the grid could enable greater integration of renewables, improve system resilience and reliability, and offer cost effective alternatives to transmission and distribution upgrades. The integration of energy storage systems into the electrical grid can lead to different environmental outcomes based on the grid application, the existing generation mix, and the demand. Given this complexity, a framework is needed to systematically inform design and technology selection about the environmental impacts that emerge when considering energy storage options to improve sustainability performance of the grid. To achieve this, 12 fundamental principles specific to the design and grid application of energy storage systems are developed to inform policy makers, designers, and operators. The principles are grouped into three categories: (1) system integration for grid applications, (2) the maintenance and operation of energy storage, and (3) the design of energy storage systems. We illustrate the application of each principle through examples published in the academic literature, illustrative calculations, and a case study with an off-grid application of vanadium redox flow batteries (VRFBs). In addition, trade-offs that can emerge between principles are highlighted.

  15. Aquifer thermal energy (heat and chill) storage

    Energy Technology Data Exchange (ETDEWEB)

    Jenne, E.A. (ed.)

    1992-11-01

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

  16. LiH thermal energy storage device

    Science.gov (United States)

    Olszewski, M.; Morris, D.G.

    1994-06-28

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

  17. Buffer thermal energy storage for an air Brayton solar engine

    Science.gov (United States)

    Strumpf, H. J.; Barr, K. P.

    1981-01-01

    The application of latent-heat buffer thermal energy storage to a point-focusing solar receiver equipped with an air Brayton engine was studied. To demonstrate the effect of buffer thermal energy storage on engine operation, a computer program was written which models the recuperator, receiver, and thermal storage device as finite-element thermal masses. Actual operating or predicted performance data are used for all components, including the rotating equipment. Based on insolation input and a specified control scheme, the program predicts the Brayton engine operation, including flows, temperatures, and pressures for the various components, along with the engine output power. An economic parametric study indicates that the economic viability of buffer thermal energy storage is largely a function of the achievable engine life.

  18. Flywheel Energy Storage Drive System for Wind Applications

    Directory of Open Access Journals (Sweden)

    Marius Constantin Georgescu

    2014-09-01

    Full Text Available This paper presents a wind small power plant with a Smart Storage Modular Structure (SSMS, as follows: a Short Time Storage Module (STSM based on a flywheel with Induction Motor (IM and a Medium/Long Time Storage Module (MLTSM based on a Vanadium Redox flow Battery (VRB. To control the speed and torque of the IM are used a nonlinear sensorless solution and a direct torque solution which have been compared. Now, the author proposes to replace the IM by a dc motor with permanent magnet energy injection. In this aim, are accomplished some laboratory tests.

  19. Energy optimization for a wind DFIG with flywheel energy storage

    Science.gov (United States)

    Hamzaoui, Ihssen; Bouchafaa, Farid

    2016-07-01

    The type of distributed generation unit that is the subject of this paper relates to renewable energy sources, especially wind power. The wind generator used is based on a double fed induction Generator (DFIG). The stator of the DFIG is connected directly to the network and the rotor is connected to the network through the power converter with three levels. The objective of this work is to study the association a Flywheel Energy Storage System (FESS) in wind generator. This system is used to improve the quality of electricity provided by wind generator. It is composed of a flywheel; an induction machine (IM) and a power electronic converter. A maximum power tracking technique « Maximum Power Point Tracking » (MPPT) and a strategy for controlling the pitch angle is presented. The model of the complete system is developed in Matlab/Simulink environment / to analyze the results from simulation the integration of wind chain to networks.

  20. Energy optimization for a wind DFIG with flywheel energy storage

    International Nuclear Information System (INIS)

    Hamzaoui, Ihssen; Bouchafaa, Farid

    2016-01-01

    The type of distributed generation unit that is the subject of this paper relates to renewable energy sources, especially wind power. The wind generator used is based on a double fed induction Generator (DFIG). The stator of the DFIG is connected directly to the network and the rotor is connected to the network through the power converter with three levels. The objective of this work is to study the association a Flywheel Energy Storage System (FESS) in wind generator. This system is used to improve the quality of electricity provided by wind generator. It is composed of a flywheel; an induction machine (IM) and a power electronic converter. A maximum power tracking technique « Maximum Power Point Tracking » (MPPT) and a strategy for controlling the pitch angle is presented. The model of the complete system is developed in Matlab/Simulink environment / to analyze the results from simulation the integration of wind chain to networks.

  1. Energy optimization for a wind DFIG with flywheel energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Hamzaoui, Ihssen, E-mail: hamzaoui-ihssen2000@yahoo.fr [Laboratory of Instrumentation, Faculty of Electronics and Computer, University of Sciences and Technology Houari Boumediene, BP 32 El-Alia 16111 Bab-Ezzouar (Algeria); Laboratory of Instrumentation, Faculty of Electronics and Computer, University of Khemis Miliana, Ain Defla (Algeria); Bouchafaa, Farid, E-mail: fbouchafa@gmail.com [Laboratory of Instrumentation, Faculty of Electronics and Computer, University of Sciences and Technology Houari Boumediene, BP 32 El-Alia 16111 Bab-Ezzouar (Algeria)

    2016-07-25

    The type of distributed generation unit that is the subject of this paper relates to renewable energy sources, especially wind power. The wind generator used is based on a double fed induction Generator (DFIG). The stator of the DFIG is connected directly to the network and the rotor is connected to the network through the power converter with three levels. The objective of this work is to study the association a Flywheel Energy Storage System (FESS) in wind generator. This system is used to improve the quality of electricity provided by wind generator. It is composed of a flywheel; an induction machine (IM) and a power electronic converter. A maximum power tracking technique « Maximum Power Point Tracking » (MPPT) and a strategy for controlling the pitch angle is presented. The model of the complete system is developed in Matlab/Simulink environment / to analyze the results from simulation the integration of wind chain to networks.

  2. Hydropower Storage May be the Key to Sustainable Energy

    International Nuclear Information System (INIS)

    Lemperiere, F.

    2009-01-01

    An analysis of future energy needs and sources should avoid utopias, clearly evaluate the needs, and quantify the potential, cost and impacts of possible solutions. Before mid century, the world will use three times the energy resources it presently requires. Most should be from renewable sources, and mainly through electricity. As the main renewable electricity sources are intermittent, some energy storage will be necessary: onshore or offshore pumped storage plants based on well proven technologies are a relevant cost-effective solution. Further needs that evolve as the century progresses might be met from solar energy or new nuclear solutions. Beyond their impact on climate change, large investments in various renewable energies and relevant storage may well be economically justified in most countries. This would also reduce the huge risk of conflict for fossil fuel control

  3. Electric Vehicles Mileage Extender Kinetic Energy Storage

    Science.gov (United States)

    Jivkov, Venelin; Draganov, Vutko; Stoyanova, Yana

    2015-03-01

    The proposed paper considers small urban vehicles with electric hybrid propulsion systems. Energy demands are examined on the basis of European drive cycle (NEUDC) and on an energy recuperation coefficient and are formulated for description of cycle energy transfers. Numerical simulation results show real possibilities for increasing in achievable vehicle mileage at the same energy levels of a main energy source - the electric battery. Kinetic energy storage (KES), as proposed to be used as an energy buffer and different structural schemes of the hybrid propulsion system are commented. Minimum energy levels for primary (the electric battery) and secondary (KES) sources are evaluated. A strategy for reduced power flows control is examined, and its impact on achievable vehicle mileage is investigated. Results show an additional increase in simulated mileage at the same initial energy levels.

  4. Nanostructured metal sulfides for energy storage.

    Science.gov (United States)

    Rui, Xianhong; Tan, Huiteng; Yan, Qingyu

    2014-09-07

    Advanced electrodes with a high energy density at high power are urgently needed for high-performance energy storage devices, including lithium-ion batteries (LIBs) and supercapacitors (SCs), to fulfil the requirements of future electrochemical power sources for applications such as in hybrid electric/plug-in-hybrid (HEV/PHEV) vehicles. Metal sulfides with unique physical and chemical properties, as well as high specific capacity/capacitance, which are typically multiple times higher than that of the carbon/graphite-based materials, are currently studied as promising electrode materials. However, the implementation of these sulfide electrodes in practical applications is hindered by their inferior rate performance and cycling stability. Nanostructures offering the advantages of high surface-to-volume ratios, favourable transport properties, and high freedom for the volume change upon ion insertion/extraction and other reactions, present an opportunity to build next-generation LIBs and SCs. Thus, the development of novel concepts in material research to achieve new nanostructures paves the way for improved electrochemical performance. Herein, we summarize recent advances in nanostructured metal sulfides, such as iron sulfides, copper sulfides, cobalt sulfides, nickel sulfides, manganese sulfides, molybdenum sulfides, tin sulfides, with zero-, one-, two-, and three-dimensional morphologies for LIB and SC applications. In addition, the recently emerged concept of incorporating conductive matrices, especially graphene, with metal sulfide nanomaterials will also be highlighted. Finally, some remarks are made on the challenges and perspectives for the future development of metal sulfide-based LIB and SC devices.

  5. Modeling of greenhouse with PCM energy storage

    International Nuclear Information System (INIS)

    Najjar, Atyah; Hasan, Afif

    2008-01-01

    Greenhouses provide a controlled environment that is suitable for plants growth and cultivation. In this paper the maximum temperature change inside the greenhouse is to be reduced by the use of energy storage in a phase change material PCM. A mathematical model is developed for the storage material and for the greenhouse. The coupled models are solved using numerical methods and Java code program. The effect of different parameters on the inside greenhouse temperature is investigated. The temperature swing between maximum and minimum values during 24 h can be reduced by 3-5 deg. C using the PCM storage. This can be improved further by enhancing the heat transfer between the PCM storage and the air inside the greenhouse

  6. Modeling of greenhouse with PCM energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Najjar, Atyah [Computation Science, Birzeit University, Birzeit (PS); Hasan, Afif [Mechanical Engineering Department, Birzeit University, Birzeit (PS)

    2008-11-15

    Greenhouses provide a controlled environment that is suitable for plants growth and cultivation. In this paper the maximum temperature change inside the greenhouse is to be reduced by the use of energy storage in a phase change material PCM. A mathematical model is developed for the storage material and for the greenhouse. The coupled models are solved using numerical methods and Java code program. The effect of different parameters on the inside greenhouse temperature is investigated. The temperature swing between maximum and minimum values during 24 h can be reduced by 3-5 C using the PCM storage. This can be improved further by enhancing the heat transfer between the PCM storage and the air inside the greenhouse. (author)

  7. An Extended VIKOR-Based Approach for Pumped Hydro Energy Storage Plant Site Selection with Heterogeneous Information

    Directory of Open Access Journals (Sweden)

    Yunna Wu

    2017-08-01

    Full Text Available The selection of a desirable site for constructing a pumped hydro energy storage plant (PHESP plays a vital important role in the whole life cycle. However, little research has been done on the site selection of PHESP, which affects the rapid development of PHESP. Therefore, this paper aims to select the most ideal PHESP site from numerous candidate alternatives using the multi-criteria decision-making (MCDM technique. Firstly, a comprehensive evaluation criteria system is established for the first time. Then, considering quantitative and qualitative criteria coexist in this system, multiple types of representations, including crisp numerical values (CNVs, triangular intuitionistic fuzzy numbers (TIFNs, and 2-dimension uncertain linguistic variables (2DULVs, are employed to deal with heterogeneous criteria information. To determine the weight of criteria and fully take the preference of the decision makers (DMs into account, the analytic hierarchy process (AHP method is applied for criteria weighting. After that, an extended Vlsekriterijumska Optimizacija I Kompromisno Resenje (VIKOR method is utilized to provide compromise solutions for the PHESP site considering such heterogeneous information. At last, the proposed model is then applied in a case study of Zhejiang province, China to illustrate its practicality and efficiency. The result shows the Changlongshan should be selected as the optimal PHESP.

  8. Storage characteristics, nutritive value, energy content, and in vivo digestibility of moist, large rectangular bales of alfalfa-orchardgrass hay treated with a propionic acid-based preservative.

    Science.gov (United States)

    Coblentz, W K; Coffey, K P; Young, A N; Bertram, M G

    2013-04-01

    Unstable weather, poor drying conditions, and unpredictable rainfall events often place valuable hay crops at risk. Recent research with large round bales composed of alfalfa (Medicago sativa L.) and orchardgrass (Dactylis glomerata L.) has shown that these large-bale packages are particularly sensitive to spontaneous heating and dry matter (DM) losses, as well as other undesirable changes with respect to forage fiber, protein, and energy density. Various formulations of organic acids have been marketed as preservatives, normally for use on hays that are not desiccated adequately in the field to facilitate safe bale storage. Our objectives for this study were to (1) evaluate the efficacy of applying a commercial (buffered) propionic acid-based preservative at 3 rates (0, 0.6, and 1.0% of wet-bale weight) to hays baled at 3 moisture concentrations (19.6, 23.8, and 27.4%) on the subsequent storage characteristics and poststorage nutritive value of alfalfa-orchardgrass forages packaged in large rectangular (285-kg) bales, and then (2) evaluate the in vivo digestibility of these hays in growing lambs. Over a 73-d storage period, the preservative was effective at limiting spontaneous heating in these hays, and a clear effect of application rate was observed for the wettest (27.4%) bales. For drier hays, both acid-application rates (1.0 and 0.6%) yielded comparable reductions in heating degree days >30°C relative to untreated controls. Reductions in spontaneous heating could not be associated with improved recovery of forage DM after storage. In this study, most changes in nutritive value during storage were related to measures of spontaneous heating in simple linear regression relationships; this suggests that the modest advantages in nutritive value resulting from acid treatment were largely associated with perturbations of normal heating patterns during bale storage. Although somewhat erratic, apparent digestibilities of both DM (Y=-0.0080x + 55.6; R(2)=0.45) and

  9. The optimization of energy storage capacity for distribution networks with the consideration of probability correlation between wind farms based on PSO algorithm

    Science.gov (United States)

    Wang, Bo; Li, Hongxia; Cao, Xueyuan; Zhu, Xiaojun; Gan, Zhongxue

    2017-04-01

    With the rapid development of the energy networks, various forms of renewable energy resources are absorbed into it. Because of the inherent random behaviour of the renewable resources, introducing them into the energy network will destroy the stability of the grids. It is required to use proper energy storages to reduce the uncertain fluctuation from the renewable energy resources. For a concrete model research, this paper presented an explicit method to give suitable capacities of the energy storages in consideration of the economics of the storage, grid losses and the probabilities of the bus voltages violation, for situations of the winds-power generations injected into the power network. Furthermore, the influence of the correlation between the different winds farms on the optimal storage capacity can also be studied by this method.

  10. A New Phase Change Material Based on Potassium Nitrate with Silica and Alumina Nanoparticles for Thermal Energy Storage.

    Science.gov (United States)

    Chieruzzi, Manila; Miliozzi, Adio; Crescenzi, Tommaso; Torre, Luigi; Kenny, José M

    2015-12-01

    In this study different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (KNO3 selected as phase change material) with nanoparticles using the direct synthesis method. The thermal properties of the nanofluids obtained were investigated. Following the improvement in the specific heat achieved, these nanofluids can be used in concentrating solar plants with a reduction of storage material. The nanoparticles used (1.0 wt.%) were silica (SiO2), alumina (Al2O3), and a mix of silica-alumina (SiO2-Al2O3) with an average diameter of 7, 13, and 2-200 nm respectively. Each nanofluid was prepared in water solution, sonicated, and evaporated. Measurements of the thermophysical properties were performed by DSC analysis, and the dispersion of the nanoparticles was analyzed by SEM microscopy. The results obtained show that the addition of 1.0 wt.% of nanoparticles to the base salt increases the specific heat of about 5-10 % in solid phase and of 6 % in liquid phase. In particular, this research shows that the addition of silica nanoparticles has significant potential for enhancing the thermal storage characteristics of KNO3. The phase-change temperature of potassium nitrate was lowered up to 3 °C, and the latent heat was increased to 12 % with the addition of silica nanoparticles. These results deviated from the predictions of theoretical simple mixing model used. The stored heat as a function of temperature was evaluated for the base salt, and the nanofluids and the maximum values obtained were 229, 234, 242, and 266 J/g respectively. The maximum total gain (16 %) due to the introduction of the nanoparticles (calculated as the ratio between the total stored heat of the nanofluids and the base salt in the range of temperatures 260-390 °C) was also recorded with the introduction of silica. SEM and EDX analysis showed the presence of aggregates in all nanofluids: with silica nanoparticles they were homogenously present while with

  11. Shutdown Policies for MEMS-Based Storage Devices -- Analytical Models

    NARCIS (Netherlands)

    Khatib, M.G.; Engelen, Johannes Bernardus Charles; Hartel, Pieter H.

    MEMS-based storage devices should be energy ecient for deployment in mobile systems. Since MEMS-based storage devices have a moving me- dia sled, they should be shut down during periods of inactivity. However, shutdown costs energy, limiting the applicability of aggressive shutdown decisions. The

  12. Thermodynamic analysis of a liquid air energy storage system

    International Nuclear Information System (INIS)

    Guizzi, Giuseppe Leo; Manno, Michele; Tolomei, Ludovica Maria; Vitali, Ruggero Maria

    2015-01-01

    The rapid increase in the share of electricity generation from renewable energy sources is having a profound impact on the power sector; one of the most relevant effects of this trend is the increased importance of energy storage systems, which can be used to smooth out peaks and troughs of production from renewable energy sources. Besides their role in balancing the electric grid, energy storage systems may provide also several other useful services, such as price arbitrage, stabilizing conventional generation, etc.; therefore, it is not surprising that many research projects are under way in order to explore the potentials of new technologies for electric energy storage. This paper presents a thermodynamic analysis of a cryogenic energy storage system, based on air liquefaction and storage in an insulated vessel. This technology is attractive thanks to its independence from geographical constraints and because it can be scaled up easily to grid-scale ratings, but it is affected by a low round-trip efficiency due to the energy intensive process of air liquefaction. The present work aims to assess the efficiency of such a system and to identify if and how it can achieve an acceptable round-trip efficiency (in the order of 50–60%).

  13. 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...

  14. Coordinated control of wind power and energy storage

    DEFF Research Database (Denmark)

    Zhao, Haoran

    in many aspects, such as reliability, power quality and stability. With the rapid development of energy storage technology, the application of Energy Storage System (ESS) is considered as an effective solution to handle the aforementioned challenges. The main objective of this study is to investigate...... speed Wind Energy Conversion System (WECS) is developed. It showed good tracking performance towards the optimum Tip Speed Ratio (TSR) and robustness with fast adaptation to uncertainties and disturbances. For the wind farm control, the optimal active power control based on Distributed Model Predictive...

  15. Solar Energy Grid Integration Systems -- Energy Storage (SEGIS-ES).

    Energy Technology Data Exchange (ETDEWEB)

    Hanley, Charles J.; Ton, Dan T. (U.S. Department of Energy, Washington, D.C.); Boyes, John D.; Peek, Georgianne Huff

    2008-07-01

    This paper describes the concept for augmenting the SEGIS Program (an industry-led effort to greatly enhance the utility of distributed PV systems) with energy storage in residential and small commercial applications (SEGIS-ES). The goal of SEGIS-ES is to develop electrical energy storage components and systems specifically designed and optimized for grid-tied PV applications. This report describes the scope of the proposed SEGIS-ES Program and why it will be necessary to integrate energy storage with PV systems as PV-generated energy becomes more prevalent on the nation's utility grid. It also discusses the applications for which energy storage is most suited and for which it will provide the greatest economic and operational benefits to customers and utilities. Included is a detailed summary of the various storage technologies available, comparisons of their relative costs and development status, and a summary of key R&D needs for PV-storage systems. The report concludes with highlights of areas where further PV-specific R&D is needed and offers recommendations about how to proceed with their development.

  16. Design and installation manual for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Cole, R L; Nield, K J; Rohde, R R; Wolosewicz, R M

    1980-01-01

    The purpose of this manual is to provide information on the design and installation of thermal energy storage in active solar systems. It is intended for contractors, installers, solar system designers, engineers, architects, and manufacturers who intend to enter the solar energy business. The reader should have general knowledge of how solar heating and cooling systems operate and knowledge of construction methods and building codes. Knowledge of solar analysis methods such as f-Chart, SOLCOST, DOE-1, or TRNSYS would be helpful. The information contained in the manual includes sizing storage, choosing a location for the storage device, and insulation requirements. Both air-based and liquid-based systems are covered with topics on designing rock beds, tank types, pump and fan selection, installation, costs, and operation and maintenance. Topics relevant to latent heat storage include properties of phase-change materials, sizing the storage unit, insulating the storage unit, available systems, and cost. Topics relevant to heating domestic water include safety, single- and dual-tank systems, domestic water heating with air- and liquid-based space heating systems, and stand alone domestics hot water systems. Several appendices present common problems with storage systems and their solutions, heat transfer fluid properties, economic insulation thickness, heat exchanger sizing, and sample specifications for heat exchangers, wooden rock bins, steel tanks, concrete tanks, and fiberglass-reinforced plastic tanks.

  17. Thermal energy storage for smart grid applications

    Science.gov (United States)

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

    2018-01-01

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

  18. Acoustic Energy Storage in Single Bubble Sonoluminescence

    NARCIS (Netherlands)

    Brenner, Michael P.; Hilgenfeldt, Sascha; Lohse, Detlef; Rosales, Rodolfo R.

    1996-01-01

    Single bubble sonoluminescence is understood in terms of a shock focusing towards the bubble center. We present a mechanism for significantly enhancing the effect of shock focusing, arising from the storage of energy in the acoustic modes of the gas. The modes with strongest coupling are not

  19. Hydrochemistry and energy storage in aquifers

    NARCIS (Netherlands)

    Andersson, O.; Appelo, C.A.J.; Brons, H.J.; Dufour, F.C.; Griffioen, J.; Jenne, E.A.; Lyklema, J.W.; Mourik, G.J. van; Snijders, A.L.; Willemsen, A.; Zehnder, A.J.B.

    1990-01-01

    This volume of the series Proceedings and Information of the TNO Committee on Hydrological Research (CHO-TNO) contains the contributions as presented on the 48th technical meeting of the CHO-TNO, "Hydrochemistry and energy storage in aquifers". During this symposium recent results have been

  20. Start It up: Flywheel Energy Storage Efficiency

    Science.gov (United States)

    Dunn, Michelle

    2011-01-01

    The purpose of this project was to construct and test an off-grid photovoltaic (PV) system in which the power from a solar array could be stored in a rechargeable battery and a flywheel motor generator assembly. The mechanical flywheel energy storage system would in turn effectively power a 12-volt DC appliance. The voltage and current of…

  1. Biogeochemical aspects of aquifer thermal energy storage

    NARCIS (Netherlands)

    Brons, H.J.

    1992-01-01

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

  2. Designing and Testing Composite Energy Storage Systems for Regulating the Outputs of Linear Wave Energy Converters

    Directory of Open Access Journals (Sweden)

    Zanxiang Nie

    2017-01-01

    Full Text Available Linear wave energy converters generate intrinsically intermittent power with variable frequency and amplitude. A composite energy storage system consisting of batteries and super capacitors has been developed and controlled by buck-boost converters. The purpose of the composite energy storage system is to handle the fluctuations and intermittent characteristics of the renewable source, and hence provide a steady output power. Linear wave energy converters working in conjunction with a system composed of various energy storage devices, is considered as a microsystem, which can function in a stand-alone or a grid connected mode. Simulation results have shown that by applying a boost H-bridge and a composite energy storage system more power could be extracted from linear wave energy converters. Simulation results have shown that the super capacitors charge and discharge often to handle the frequent power fluctuations, and the batteries charge and discharge slowly for handling the intermittent power of wave energy converters. Hardware systems have been constructed to control the linear wave energy converter and the composite energy storage system. The performance of the composite energy storage system has been verified in experiments by using electronics-based wave energy emulators.

  3. Hydrogen-air energy storage gas-turbine system

    Science.gov (United States)

    Schastlivtsev, A. I.; Nazarova, O. V.

    2016-02-01

    A hydrogen-air energy storage gas-turbine unit is considered that can be used in both nuclear and centralized power industries. However, it is the most promising when used for power-generating plants based on renewable energy sources (RES). The basic feature of the energy storage system in question is combination of storing the energy in compressed air and hydrogen and oxygen produced by the water electrolysis. Such a process makes the energy storage more flexible, in particular, when applied to RES-based power-generating plants whose generation of power may considerably vary during the course of a day, and also reduces the specific cost of the system by decreasing the required volume of the reservoir. This will allow construction of such systems in any areas independent of the local topography in contrast to the compressed-air energy storage gas-turbine plants, which require large-sized underground reservoirs. It should be noted that, during the energy recovery, the air that arrives from the reservoir is heated by combustion of hydrogen in oxygen, which results in the gas-turbine exhaust gases practically free of substances hazardous to the health and the environment. The results of analysis of a hydrogen-air energy storage gas-turbine system are presented. Its layout and the principle of its operation are described and the basic parameters are computed. The units of the system are analyzed and their costs are assessed; the recovery factor is estimated at more than 60%. According to the obtained results, almost all main components of the hydrogen-air energy storage gas-turbine system are well known at present; therefore, no considerable R&D costs are required. A new component of the system is the H2-O2 combustion chamber; a difficulty in manufacturing it is the necessity of ensuring the combustion of hydrogen in oxygen as complete as possible and preventing formation of nitric oxides.

  4. Low-Cost and High-Productivity Three-Dimensional Nanocapacitors Based on Stand-Up ZnO Nanowires for Energy Storage.

    Science.gov (United States)

    Wei, Lei; Liu, Qi-Xuan; Zhu, Bao; Liu, Wen-Jun; Ding, Shi-Jin; Lu, Hong-Liang; Jiang, Anquan; Zhang, David Wei

    2016-12-01

    Highly powered electrostatic capacitors based on nanostructures with a high aspect ratio are becoming critical for advanced energy storage technology because of their high burst power and energy storage capability. We report the fabrication process and the electrical characteristics of high capacitance density capacitors with three-dimensional solid-state nanocapacitors based on a ZnO nanowire template. Stand-up ZnO nanowires are grown face down on p-type Si substrates coated with a ZnO seed layer using a hydrothermal method. Stacks of AlZnO/Al2O3/AlZnO are then deposited sequentially on the ZnO nanowires using atomic layer deposition. The fabricated capacitor has a high capacitance density up to 92 fF/μm(2) at 1 kHz (around ten times that of the planar capacitor without nanowires) and an extremely low leakage current density of 3.4 × 10(-8) A/cm(2) at 2 V for a 5-nm Al2O3 dielectric. Additionally, the charge-discharge characteristics of the capacitor were investigated, indicating that the resistance-capacitance time constants were 550 ns for both the charging and discharging processes and the time constant was not dependent on the voltage. This reflects good power characteristics of the fabricated capacitors. Therefore, the current work provides an exciting strategy to fabricate low-cost and easily processable, high capacitance density capacitors for energy storage.

  5. Energy storage for electrical systems in the USA

    Directory of Open Access Journals (Sweden)

    Eugene Freeman

    2016-10-01

    Full Text Available Energy storage is becoming increasingly important as renewable generation sources such as Wind Turbine and Photo Voltaic Solar are added to the mix in electrical power generation and distribution systems. The paper discusses the basic drivers for energy storage and provides brief descriptions of the various energy storage technologies available. The information summarizes current technical tradeoffs with different storage approaches and identifies issues surrounding deployment of large scale energy storage systems.

  6. Analysis Insights: Energy Storage - Possibilities for Expanding Electric Grid Flexibility

    Energy Technology Data Exchange (ETDEWEB)

    2016-02-01

    NREL Analysis Insights mines our body of analysis work to synthesize topical insights and key findings. In this issue, we explore energy storage and the role it is playing and could potentially play in increasing grid flexibility and renewable energy integration. We explore energy storage as one building block for a more flexible power system, policy and R and D as drivers of energy storage deployment, methods for valuing energy storage in grid applications, ways that energy storage supports renewable integration, and emerging opportunities for energy storage in the electric grid.

  7. High to ultra-high power electrical energy storage.

    Science.gov (United States)

    Sherrill, Stefanie A; Banerjee, Parag; Rubloff, Gary W; Lee, Sang Bok

    2011-12-14

    High power electrical energy storage systems are becoming critical devices for advanced energy storage technology. This is true in part due to their high rate capabilities and moderate energy densities which allow them to capture power efficiently from evanescent, renewable energy sources. High power systems include both electrochemical capacitors and electrostatic capacitors. These devices have fast charging and discharging rates, supplying energy within seconds or less. Recent research has focused on increasing power and energy density of the devices using advanced materials and novel architectural design. An increase in understanding of structure-property relationships in nanomaterials and interfaces and the ability to control nanostructures precisely has led to an immense improvement in the performance characteristics of these devices. In this review, we discuss the recent advances for both electrochemical and electrostatic capacitors as high power electrical energy storage systems, and propose directions and challenges for the future. We asses the opportunities in nanostructure-based high power electrical energy storage devices and include electrochemical and electrostatic capacitors for their potential to open the door to a new regime of power energy.

  8. Flexible, highly graphitized carbon aerogels based on bacterial cellulose/lignin: Catalyst-free synthesis and its application in energy storage devices

    KAUST Repository

    Xu, Xuezhu

    2015-04-15

    Currently, most carbon aerogels are based on carbon nanotubes (CNTs) or graphene, which are produced through a catalyst-assisted chemical vapor deposition method. Biomass based organic aerogels and carbon aerogels, featuring low cost, high scalability, and small environmental footprint, represent an important new research direction in (carbon) aerogel development. Cellulose and lignin are the two most abundant natural polymers in the world, and the aerogels based on them are very promising. Classic silicon aerogels and available organic resorcinol-formaldehyde (RF) or lignin-resorcinol-formaldehyde (LRF) aerogels are brittle and fragile; toughening of the aerogels is highly desired to expand their applications. This study reports the first attempt to toughen the intrinsically brittle LRF aerogel and carbon aerogel using bacterial cellulose. The facile process is catalyst-free and cost-effective. The toughened carbon aerogels, consisting of blackberry-like, core-shell structured, and highly graphitized carbon nanofibers, are able to undergo at least 20% reversible compressive deformation. Due to their unique nanostructure and large mesopore population, the carbon materials exhibit an areal capacitance higher than most of the reported values in the literature. This property makes them suitable candidates for flexible solid-state energy storage devices. Besides energy storage, the conductive interconnected nanoporous structure can also find applications in oil/water separation, catalyst supports, sensors, and so forth. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Glass ceramic approaches for energy storage materials

    Science.gov (United States)

    Davis, Calvin Goodwin, III

    Glass ceramics are an advanced material class that exhibit excellent potential for energy storage applications. Unique properties can be obtained through the controlled crystallization that is used to form these glassy and crystalline composite materials from an amorphous bulk. By exploiting this synthesis route, materials can be optimized to offer the best balance between the crystalline ceramic phase, and the amorphous glass phase. The topic of this dissertation focuses on the structure-property relationships for glass ceramic systems for energy storage applications. Specifically, a lithium aluminum titanium phosphate system, and a barium sodium niobate system were explored for battery and capacitor applications, respectively. Li1+xAlxTi2-x(PO4)3 (LATP) is a lithium ion conductor which has shown potential for use in current and future battery technology. In its glass ceramic form the material has a conductivity of approximately 10-4 S/cm, which makes it an excellent conductor compared to other solid state lithium ion conductors. This conductivity is still lower than ionic liquids and polymers with currently used as electrolytes with conductivity higher than 10-3 S/cm. In exploring synthesis routes, it was found that microwave hybrid heating offered improve conductivity, as opposed to conventional crystallization methods. The role of microstructure and the crystallization kinetics on the overall have been investigated. It was shown that commonly used Johnson-Mehl-Avrami equation could not accurately describe the kinetics of LATP's nucleation and growth. An empirical Sestak-Berggren model was used in combination with differential scanning calorimetry data to model the kinetics of LATP. Glass ceramic systems based on a NaBa2Nb5O 15 (BNN) crystalline have shown potential as dielectrics in high energy density capacitors. Here microwave hybrid heating and conventional heating were used to crystallize BNN glass ceramics in the range of 750°C - 1000°C, and the results

  10. Fuzzy droop control loops adjustment for stored energy balance in distributed energy storage system

    DEFF Research Database (Denmark)

    Aldana, Nelson Leonardo Diaz; Wu, Dan; Dragicevic, Tomislav

    2015-01-01

    The study of isolated AC microgrid has been under high interest due to the integration of renewable energy resources especially for remote areas, or to improve the local energy reliability. The current trend is oriented to distributed renewable energy sources and their corresponding energy storage...... system, in order to smooth the variations at the prime energy generator. In this paper, a decentralized strategy based on fuzzy logic is proposed in order to balance the state of charge of distributed energy storage systems in lowvoltage three phase AC microgrid. The proposed method weights the action...... of conventional droop control loops for battery based distributed energy storage systems, in order to equalize their stored energy. The units are selfcontrolled by using local variables, hence, the microgrid can operate without communication systems. Frequency and voltage bus signaling are used in order...

  11. Electrokinetic Supercapacitor for Simultaneous Harvesting and Storage of Mechanical Energy.

    Science.gov (United States)

    Yang, Peihua; Qu, Xiaopeng; Liu, Kang; Duan, Jiangjiang; Li, Jia; Chen, Qian; Xue, Guobin; Xie, Wenke; Xu, Zhimou; Zhou, Jun

    2018-03-07

    Energy harvesting and storage are two distinct processes that are generally achieved using two separated parts based on different physical and chemical principles. Here we report a self-charging electrokinetic supercapacitor that directly couples the energy harvesting and storage processes into one device. The device consists of two identical carbon nanotube/titanium electrodes, separated by a piece of anodic aluminum oxide nanochannels membrane. Pressure-driven electrolyte flow through the nanochannels generates streaming potential, which can be used to charge the capacitive electrodes, accomplishing simultaneous energy generation and storage. The device stores electric charge density of 0.4 mC cm -2 after fully charging under pressure of 2.5 bar. This work may offer a train of thought for the development of a new type of energy unit for self-powered systems.

  12. Legal and regulatory issues affecting compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, P.L.

    1981-07-01

    Several regulatory and legal issues that can potentially affect implementation of a compressed air energy storage (CAES) system are discussed. This technology involves the compression of air using base load electric power for storage in an underground storage medium. The air is subsequently released and allowed to pass through a turbine to generate electricity during periods of peak demand. The storage media considered most feasible are a mined hard rock cavern, a solution-mined cavern in a salt deposit, and a porous geologic formation (normally an aquifer) of suitable structure. The issues are discussed in four categories: regulatory issues common to most CAES facilities regardless of storage medium, regulatory issues applicable to particular CAES reservoir media, issues related to possible liability from CAES operations, and issues related to acquisition of appropriate property rights for CAES implementation. The focus is on selected federal regulation. Lesser attention is given to state and local regulation. (WHK)

  13. Electrical Energy Storage for Renewable Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Helms, C. R. [Univ. of Texas, Dallas, TX (United States); Cho, K. J. [Univ. of Texas, Dallas, TX (United States); Ferraris, John [Univ. of Texas, Dallas, TX (United States); Balkus, Ken [Univ. of Texas, Dallas, TX (United States); Chabal, Yves [Univ. of Texas, Dallas, TX (United States); Gnade, Bruce [Univ. of Texas, Dallas, TX (United States); Rotea, Mario [Univ. of Texas, Dallas, TX (United States); Vasselli, John [Univ. of Texas, Dallas, TX (United States)

    2012-08-31

    This program focused on development of the fundamental understanding necessary to significantly improve advanced battery and ultra-capacitor materials and systems to achieve significantly higher power and energy density on the one hand, and significantly lower cost on the other. This program spanned all the way from atomic-level theory, to new nanomaterials syntheses and characterization, to system modeling and bench-scale technology demonstration. This program not only delivered significant advancements in fundamental understanding and new materials and technology, it also showcased the power of the cross-functional, multi-disciplinary teams at UT Dallas and UT Tyler for such work. These teams are continuing this work with other sources of funding from both industry and government.

  14. Dielectric and energy storage performances of PVDF-based composites with colossal permittivitied Nd-doped BaTiO3 nanoparticles as the filler

    Science.gov (United States)

    Wang, Jing; Hu, Juntao; Sun, Qiaomei; Zhu, Kongjun; Li, Bao-Wen; Qiu, Jinhao

    2017-12-01

    The energy storage density of pure polymers is usually limited by their low intrinsic dielectric constants (ɛeff). Integrating polymer matrix with ceramic particles with high ɛeff values has been one powerful approach to enhance the ɛeff values of polymer composites and thus their energy storage density. In this study, we report a flexible polymer-based composite by introducing Nd-doped BaTiO3 (NBT) nanoparticles (ɛeff over 3×105) into the poly(vinylidene fluoride) (PVDF). The phase of PVDF and its dielectric behavior could be adjusted by varying the NBT loadings. Composites including less than 5 vol.% NBT loading exhibited enhanced dielectric constants and maintained high breakdown strength. With a quenching process, the composite delivers a discharged energy density up to 7.91 J/cm3 at an electric field of 350 kV/mm with 2.5 vol.% NBT loading, which is 140% more than that of pure PVDF at the same electric field.

  15. Planning for a 100% independent energy system based on smart energy storage for integration of renewables and CO2 emissions reduction

    DEFF Research Database (Denmark)

    Krajačić, Goran; Duić, Neven; Zmijarević, Zlatko

    2011-01-01

    EU import dependence on hydrocarbons and resulting negative environmental impact related to their use led to setting of new measures and energy policy that will make, in time, a post carbon society more feasible and achievable. Energy systems of this society will be based on four pillars: Renewab...... and financial analyses have been carried out for periods of one year taking into consideration demands and renewable energy production during all hours.......EU import dependence on hydrocarbons and resulting negative environmental impact related to their use led to setting of new measures and energy policy that will make, in time, a post carbon society more feasible and achievable. Energy systems of this society will be based on four pillars: Renewable...

  16. Energy Storage. Teachers Guide. Science Activities in Energy.

    Science.gov (United States)

    Jacobs, Mary Lynn, Ed.

    Included in this science activities energy package for students in grades 4-10 are 12 activities related to energy storage. Each activity is outlined on the front and back of a single sheet and is introduced by a key question. Most of the activities can be completed in the classroom with materials readily available in any community. Among the…

  17. Flywheel energy storage for electromechanical actuation systems

    Science.gov (United States)

    Hockney, Richard L.; Goldie, James H.; Kirtley, James L.

    The authors describe a flywheel energy storage system designed specifically to provide load-leveling for a thrust vector control (TVC) system using electromechanical actuators (EMAs). One of the major advantages of an EMA system over a hydraulic system is the significant reduction in total energy consumed during the launch profile. Realization of this energy reduction will, however, require localized energy storage capable of delivering the peak power required by the EMAs. A combined flywheel-motor/generator unit which interfaces directly to the 20-kHz power bus represents an ideal candidate for this load leveling. The overall objective is the definition of a flywheel energy storage system for this application. The authors discuss progress on four technical objectives: (1) definition of the specifications for the flywheel-motor/generator system, including system-level trade-off analysis; (2) design of the flywheel rotor; (3) design of the motor/generator; and (4) determination of the configuration for the power management system.

  18. Adiabatic Liquid Piston Compressed Air Energy Storage

    DEFF Research Database (Denmark)

    Petersen, Tage; Elmegaard, Brian; Pedersen, Allan Schrøder

    This project investigates the potential of a Compressed Air Energy Storage system (CAES system). CAES systems are used to store mechanical energy in the form of compressed air. The systems use electricity to drive the compressor at times of low electricity demand with the purpose of converting...... the mechanical energy into electricity at times of high electricity demand. Two such systems are currently in operation; one in Germany (Huntorf) and one in the USA (Macintosh, Alabama). In both cases, an underground cavern is used as a pressure vessel for the storage of the compressed air. Both systems...... are in the range of 100 MW electrical power output with several hours of production stored as compressed air. In this range, enormous volumes are required, which make underground caverns the only economical way to design the pressure vessel. Both systems use axial turbine compressors to compress air when charging...

  19. Two-dimensional heterostructures for energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Gogotsi, Yury G. [Drexel Univ., Philadelphia, PA (United States); Pomerantseva, Ekaterina [Drexel Univ., Philadelphia, PA (United States)

    2017-06-12

    Two-dimensional (2D) materials provide slit-shaped ion diffusion channels that enable fast movement of lithium and other ions. However, electronic conductivity, the number of intercalation sites, and stability during extended cycling are also crucial for building high-performance energy storage devices. While individual 2D materials, such as graphene, show some of the required properties, none of them can offer all properties needed to maximize energy density, power density, and cycle life. Here we argue that stacking different 2D materials into heterostructured architectures opens an opportunity to construct electrodes that would combine the advantages of the individual building blocks while eliminating the associated shortcomings. We discuss characteristics of common 2D materials and provide examples of 2D heterostructured electrodes that showed new phenomena leading to superior electrochemical performance. As a result, we also consider electrode fabrication approaches and finally outline future steps to create 2D heterostructured electrodes that could greatly expand current energy storage technologies.

  20. One-dimensional nanomaterials for energy storage

    Science.gov (United States)

    Chen, Cheng; Fan, Yuqi; Gu, Jianhang; Wu, Liming; Passerini, Stefano; Mai, Liqiang

    2018-03-01

    The search for higher energy density, safer, and longer cycling-life energy storage systems is progressing quickly. One-dimensional (1D) nanomaterials have a large length-to-diameter ratio, resulting in their unique electrical, mechanical, magnetic and chemical properties, and have wide applications as electrode materials in different systems. This article reviews the latest hot topics in applying 1D nanomaterials, covering both their synthesis and their applications. 1D nanomaterials can be grouped into the categories: carbon, silicon, metal oxides, and conducting polymers, and we structure our discussion accordingly. Then, we survey the unique properties and application of 1D nanomaterials in batteries and supercapacitors, and provide comments on the progress and advantages of those systems, paving the way for a better understanding of employing 1D nanomaterials for energy storage.

  1. Evaluation of thermal energy storage materials for advanced compressed air energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Zaloudek, F.R.; Wheeler, K.R.; Marksberry, L.

    1983-03-01

    Advanced Compressed-Air Energy Storage (ACAS) plants have the near-term potential to reduce the fuel consumption of compressed-air plants from 33 to 100%, depending upon their design. Fuel is saved by storing some or all of the heat of compression as sensible heat which is subsequently used to reheat the compressed air prior to expansion in the turbine generator. The thermal storage media required for this application must be low cost and durable. The objective of this project was to screen thermal store materials based on their thermal cycle durability, particulate formation and corrosion resistant characteristics. The materials investigated were iron oxide pellets, Denstone pebbles, cast-iron balls, and Dresser basalt rock. The study specifically addressed the problems of particle formation and thermal ratcheting of the materials during thermal cycling and the chemical attack on the materials by the high temperature and moist environment in an ACAS heat storage bed. The results indicate that from the durability standpoint Denstone, cast iron containing 27% or more chromium, and crushed Dresser basalt would possibly stand up to ACAS conditions. If costs are considered in addition to durability and performance, the crushed Dresser basalt would probably be the most desirable heat storage material for adiabatic and hybrid ACAS plants, and more in-depth longer term thermal cycling and materials testing of Dresser basalt is recommended. Also recommended is the redesign and costing analysis of both the hybrid and adiabatic ACAS facilities based upon the use of Dresser basalt as the thermal store material.

  2. Profit by storage value analysis of battery energy storage applications; Profit durch Speicherung. Analyse zur Wirtschaftlichkeit von Batteriespeicher-Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Oudalov, A.; Chartouni, D.; Ohler, C.; Buehler, T.; Linhofer, G. [ABB-Forschungszentrum (Switzerland)

    2006-07-01

    Energy storage systems based on batteries can be employed profitably in power systems under specific circumstances. In the following manuscript three potential applications are analysed. It is shown that a battery energy storage system used as a primary reserve is the economically most viable application. (orig.)

  3. Solar energy storage researchers information user study

    Energy Technology Data Exchange (ETDEWEB)

    Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

    1981-03-01

    The results of a series of telephone interviews with groups of users of information on solar energy storage are described. In the current study only high-priority groups were examined. Results from 2 groups of researchers are analyzed: DOE-Funded Researchers and Non-DOE-Funded Researchers. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

  4. Energy Conversion & Storage Program, 1993 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, E.J.

    1994-06-01

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

  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. Form-Stable Phase Change Materials Based on Eutectic Mixture of Tetradecanol and Fatty Acids for Building Energy Storage: Preparation and Performance Analysis.

    Science.gov (United States)

    Huang, Jingyu; Lu, Shilei; Kong, Xiangfei; Liu, Shangbao; Li, Yiran

    2013-10-22

    This paper is focused on preparation and performance analysis of a series of form-stable phase change materials (FSPCMs), based on eutectic mixtures as phase change materials (PCMs) for thermal energy storage and high-density polyethylene (HDPE)-ethylene-vinyl acetate (EVA) polymer as supporting materials. The PCMs were eutectic mixtures of tetradecanol (TD)-capric acid (CA), TD-lauric acid (LA), and TD-myristic acid (MA), which were rarely explored before. Thermal properties of eutectic mixtures and FSPCMs were measured by differential scanning calorimeter (DSC). The onset melting/solidification temperatures of form-stable PCMs were 19.13 °C/13.32 °C (FS TD-CA PCM), 24.53 °C/24.92 °C (FS TD-LA PCM), and 33.15 °C/30.72 °C (FS TD-MA PCM), respectively, and latent heats were almost greater than 90 J/g. The surface morphologies and chemical stability of form-stable PCM were surveyed by scanning electron microscopy (SEM) and Fourier-transform infrared (FT-IR) spectroscopy, respectively. The thermal cycling test revealed that the thermal reliability of these three form-stable PCMs was good. Thermal storage/release experiment indicated melting/solidification time was shortened by introducing 10 wt % aluminum powder (AP). It is concluded that these FSPCMs can act as potential building thermal storage materials in terms of their satisfactory thermal properties.

  7. Form-Stable Phase Change Materials Based on Eutectic Mixture of Tetradecanol and Fatty Acids for Building Energy Storage: Preparation and Performance Analysis

    Directory of Open Access Journals (Sweden)

    Yiran li

    2013-10-01

    Full Text Available This paper is focused on preparation and performance analysis of a series of form-stable phase change materials (FSPCMs, based on eutectic mixtures as phase change materials (PCMs for thermal energy storage and high-density polyethylene (HDPE-ethylene-vinyl acetate (EVA polymer as supporting materials. The PCMs were eutectic mixtures of tetradecanol (TD–capric acid (CA, TD–lauric acid (LA, and TD–myristic acid (MA, which were rarely explored before. Thermal properties of eutectic mixtures and FSPCMs were measured by differential scanning calorimeter (DSC. The onset melting/solidification temperatures of form-stable PCMs were 19.13 °C/13.32 °C (FS TD–CA PCM, 24.53 °C/24.92 °C (FS TD–LA PCM, and 33.15 °C/30.72 °C (FS TD–MA PCM, respectively, and latent heats were almost greater than 90 J/g. The surface morphologies and chemical stability of form-stable PCM were surveyed by scanning electron microscopy (SEM and Fourier-transform infrared (FT-IR spectroscopy, respectively. The thermal cycling test revealed that the thermal reliability of these three form-stable PCMs was good. Thermal storage/release experiment indicated melting/solidification time was shortened by introducing 10 wt % aluminum powder (AP. It is concluded that these FSPCMs can act as potential building thermal storage materials in terms of their satisfactory thermal properties.

  8. Form-Stable Phase Change Materials Based on Eutectic Mixture of Tetradecanol and Fatty Acids for Building Energy Storage: Preparation and Performance Analysis

    Science.gov (United States)

    Huang, Jingyu; Lu, Shilei; Kong, Xiangfei; Liu, Shangbao; li, Yiran

    2013-01-01

    This paper is focused on preparation and performance analysis of a series of form-stable phase change materials (FSPCMs), based on eutectic mixtures as phase change materials (PCMs) for thermal energy storage and high-density polyethylene (HDPE)-ethylene-vinyl acetate (EVA) polymer as supporting materials. The PCMs were eutectic mixtures of tetradecanol (TD)–capric acid (CA), TD–lauric acid (LA), and TD–myristic acid (MA), which were rarely explored before. Thermal properties of eutectic mixtures and FSPCMs were measured by differential scanning calorimeter (DSC). The onset melting/solidification temperatures of form-stable PCMs were 19.13 °C/13.32 °C (FS TD–CA PCM), 24.53 °C/24.92 °C (FS TD–LA PCM), and 33.15 °C/30.72 °C (FS TD–MA PCM), respectively, and latent heats were almost greater than 90 J/g. The surface morphologies and chemical stability of form-stable PCM were surveyed by scanning electron microscopy (SEM) and Fourier-transform infrared (FT-IR) spectroscopy, respectively. The thermal cycling test revealed that the thermal reliability of these three form-stable PCMs was good. Thermal storage/release experiment indicated melting/solidification time was shortened by introducing 10 wt % aluminum powder (AP). It is concluded that these FSPCMs can act as potential building thermal storage materials in terms of their satisfactory thermal properties. PMID:28788358

  9. Energy storage for improvement of wind power characteristics

    DEFF Research Database (Denmark)

    Rasmussen, Claus Nygaard

    2011-01-01

    Results from simulation of the influence of energy storage on the variability and availability of wind energy are presented here. Simulations have been done using a mathematical model of energy storage implemented in MATLAB. The obtained results show the quality improvement, of energy delivered...... by a combination of wind and energy storage, in relation to the size of the energy storage. The introduction of storage enables suppression of wind power fluctuations up to a timescale proportional to the storage energy capacity. Energy storage cannot provide availability of wind power at all times, but it can...... guarantee that a certain fraction of average wind power will be available within a given timeframe. The amount of storage energy capacity necessary for significant improvement of wind power availability, within a given period, is found to be approximately 20% of the energy produced in that period...

  10. Entropy, pumped-storage and energy system finance

    Science.gov (United States)

    Karakatsanis, Georgios

    2015-04-01

    Pumped-storage holds a key role for integrating renewable energy units with non-renewable fuel plants into large-scale energy systems of electricity output. An emerging issue is the development of financial engineering models with physical basis to systematically fund energy system efficiency improvements across its operation. A fundamental physically-based economic concept is the Scarcity Rent; which concerns the pricing of a natural resource's scarcity. Specifically, the scarcity rent comprises a fraction of a depleting resource's full price and accumulates to fund its more efficient future use. In an integrated energy system, scarcity rents derive from various resources and can be deposited to a pooled fund to finance the energy system's overall efficiency increase; allowing it to benefit from economies of scale. With pumped-storage incorporated to the system, water upgrades to a hub resource, in which the scarcity rents of all connected energy sources are denominated to. However, as available water for electricity generation or storage is also limited, a scarcity rent upon it is also imposed. It is suggested that scarcity rent generation is reducible to three (3) main factors, incorporating uncertainty: (1) water's natural renewability, (2) the energy system's intermittent components and (3) base-load prediction deviations from actual loads. For that purpose, the concept of entropy is used in order to measure the energy system's overall uncertainty; hence pumped-storage intensity requirements and generated water scarcity rents. Keywords: pumped-storage, integration, energy systems, financial engineering, physical basis, Scarcity Rent, pooled fund, economies of scale, hub resource, uncertainty, entropy Acknowledgement: This research was funded by the Greek General Secretariat for Research and Technology through the research project Combined REnewable Systems for Sustainable ENergy DevelOpment (CRESSENDO; grant number 5145)

  11. Hydrogen Energy Storage (HES) Activities at NREL; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Eichman, J.

    2015-04-21

    This presentation provides an overview of hydrogen and energy storage, including hydrogen storage pathways and international power-to-gas activities, and summarizes the National Renewable Energy Laboratory's hydrogen energy storage activities and results.

  12. Energy storage reinforces competitive business practices

    International Nuclear Information System (INIS)

    Makansi, J.

    1994-01-01

    This article examines how the ability to ''store'' electricity can pay handsome dividends in a competitive environment. Priorities change when industries are deregulated. Indeed, new priorities are being established for electric generation--low cost, efficiency, product distinction for marketing purposes, etc. are all more critical today. Perhaps not so obvious is the fundamental role of energy storage in a fully competitive marketplace. In fact, rarely do a technology development and a changing business climate play off against each other so nicely. Consider the function of the emerging electricity broker, or power marketer. Imagine the premium that broker could command with access to a large increment of electricity--purchased at a low price--and supplied at a moment's notice for a substantially higher price. Storage of electricity would mean that the investment in excess available generation capacity to supply so-called peak demand could be avoided. It also means that electricity could be brokered like other commodities--that is purchased, stockpiled, and sold to reflect market conditions across a wider geographical region and time spain. Benefits accrue to transmission and distribution, in addition to generation. Energy storage helps to manage the increasing stress placed on the grid as a result of intermittent sources of power and large numbers of cogenerators and small power producers. On the customer side, any ratepayer large or small could, theoretically, play the spot market in electric supply with a reserve to tap in emergencies. For a parallel in other deregulated markets, recall how storage has become an important factor in natural-gas contracting. Quality of electricity also can be improved by applying storage to stabilize the grid, especially along the distribution system at substations. And the opening of vast markets for electricity consumption, such as electric vehicles, depends in large measure on electric storage

  13. Advanced storage concepts for solar and low energy buildings, IEA-SHC Task 32. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, J.M.; Andersen, Elsa; Furbo, S.

    2008-01-15

    This report reports on the results of the activities carried through in connection with the Danish part of the IEA SHC Task 32 project: Advanced Storage Concepts for Solar and Low Energy Buildings. The Danish involvement has focused on Subtask C: Storage Concepts Based on Phase Change Materials and Subtask D: Storage Concepts Based on Advanced Water Tanks and Special Devices. The report describes activities concerning heat-of-fusion storage and advanced water storage. (BA)

  14. Commercialization of aquifer thermal energy storage technology

    Energy Technology Data Exchange (ETDEWEB)

    Hattrup, M.P.; Weijo, R.O.

    1989-09-01

    Pacific Northwest Laboratory (PNL) conducted this study for the US Department of Energy's (DOE) Office of Energy Storage and Distribution. The purpose of the study was to develop and screen a list of potential entry market applications for aquifer thermal energy storage (ATES). Several initial screening criteria were used to identify promising ATES applications. These include the existence of an energy availability/usage mismatch, the existence of many similar applications or commercial sites, the ability to utilize proven technology, the type of location, market characteristics, the size of and access to capital investment, and the number of decision makers involved. The in-depth analysis identified several additional screening criteria to consider in the selection of an entry market application. This analysis revealed that the best initial applications for ATES are those where reliability is acceptable, and relatively high temperatures are allowable. Although chill storage was the primary focus of this study, applications that are good candidates for heat ATES were also of special interest. 11 refs., 3 tabs.

  15. Flexible energy-storage devices: design consideration and recent progress.

    Science.gov (United States)

    Wang, Xianfu; Lu, Xihong; Liu, Bin; Chen, Di; Tong, Yexiang; Shen, Guozhen

    2014-07-23

    Flexible energy-storage devices are attracting increasing attention as they show unique promising advantages, such as flexibility, shape diversity, light weight, and so on; these properties enable applications in portable, flexible, and even wearable electronic devices, including soft electronic products, roll-up displays, and wearable devices. Consequently, considerable effort has been made in recent years to fulfill the requirements of future flexible energy-storage devices, and much progress has been witnessed. This review describes the most recent advances in flexible energy-storage devices, including flexible lithium-ion batteries and flexible supercapacitors. The latest successful examples in flexible lithium-ion batteries and their technological innovations and challenges are reviewed first. This is followed by a detailed overview of the recent progress in flexible supercapacitors based on carbon materials and a number of composites and flexible micro-supercapacitors. Some of the latest achievements regarding interesting integrated energy-storage systems are also reviewed. Further research direction is also proposed to surpass existing technological bottle-necks and realize idealized flexible energy-storage devices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Model-based assessment of the potential of seasonal aquifer thermal energy storage and recovery as a groundwater ecosystem service for the Brussels-Capital Region

    Science.gov (United States)

    Anibas, Christian; Huysmans, Marijke

    2015-04-01

    Urban areas are characterized by their concentrated demand of energy, applying a high pressure on urban ecosystems including atmosphere, soils and groundwater. In the light of global warming, urbanization and an evolving energy system, it is important to know how urbanized areas can contribute to their own energy demands. One option is to use the possibilities aquifers offer as an ecosystem service (BONTE et al., 2011). If used effectively an improvement in air and groundwater quality is achieved. Additionally, the more efficient distribution of the used energy may also lead to a decrease in primary energy consumption (ZUURBIER, 2013). Therefore, investigations of the potential of seasonal aquifer thermal energy storage and recovery (ATES) for the Brussels-Capital Region, Belgium is being conducted. The potential of ATES systems are of special interest for energy demands in high density urban areas because of such infrastructure as office buildings, schools, hospitals and shopping malls. In an open water circuit ATES systems consist of two or more groundwater wells, where in seasonal cycles one subtracts and the other recharges water to the aquifer. Heat pumps use the heat capacity of water for heating or cooling a building. An important limitation of the methodology is the quality of the groundwater used (i.e. precipitation of Fe- or Mn-oxides can decrease the yield). However, ATES systems on the other hand can also improve groundwater quality and groundwater ecosystems. The current knowledge of the potential for ATES systems in the Brussels-Capital Region is based on geological assessments from VITO (2007). The Brussels-Capital Region is divided into a western and eastern section with respect to geology. While the western part has less favorable conditions for ATES, the eastern is composed of the Brussels Sand formation, which is a 20-40 m thick aquifer layer that has the highest potential for ATES systems in the region. By applying groundwater flow and heat

  17. Energy Storage and Distributed Energy Generation Project, Final Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Schwank, Johannes; Mader, Jerry; Chen, Xiaoyin; Mi, Chris; Linic, Suljo; Sastry, Ann Marie; Stefanopoulou, Anna; Thompson, Levi; Varde, Keshav

    2008-03-31

    This report serves as a Final Report under the “Energy Storage and Distribution Energy Generation Project” carried out by the Transportation Energy Center (TEC) at the University of Michigan (UM). An interdisciplinary research team has been working on fundamental and applied research on: -distributed power generation and microgrids, -power electronics, and -advanced energy storage. The long-term objective of the project was to provide a framework for identifying fundamental research solutions to technology challenges of transmission and distribution, with special emphasis on distributed power generation, energy storage, control methodologies, and power electronics for microgrids, and to develop enabling technologies for novel energy storage and harvesting concepts that can be simulated, tested, and scaled up to provide relief for both underserved and overstressed portions of the Nation’s grid. TEC’s research is closely associated with Sections 5.0 and 6.0 of the DOE "Five-year Program Plan for FY2008 to FY2012 for Electric Transmission and Distribution Programs, August 2006.”

  18. Fiber-shaped energy harvesting and storage devices

    CERN Document Server

    Peng, Huisheng

    2015-01-01

    This comprehensive book covers flexible fiber-shaped devices in the area of energy conversion and storage. The first part of the book introduces recently developed materials, particularly, various nanomaterials and composite materials based on nanostructured carbon such as carbon nanotubes and graphene, metals and polymers for the construction of fiber electrodes. The second part of the book focuses on two typical twisted and coaxial architectures of fiber-shaped devices for energy conversion and storage. The emphasis is placed on dye-sensitized solar cells, polymer solar cells, lithium-ion b

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

    Science.gov (United States)

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

    2014-09-01

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

  20. Advanced Energy Storage Management in Distribution Network

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guodong [ORNL; Ceylan, Oguzhan [ORNL; Xiao, Bailu [ORNL; Starke, Michael R [ORNL; Ollis, T Ben [ORNL; King, Daniel J [ORNL; Irminger, Philip [ORNL; Tomsovic, Kevin [University of Tennessee, Knoxville (UTK)

    2016-01-01

    With increasing penetration of distributed generation (DG) in the distribution networks (DN), the secure and optimal operation of DN has become an important concern. In this paper, an iterative mixed integer quadratic constrained quadratic programming model to optimize the operation of a three phase unbalanced distribution system with high penetration of Photovoltaic (PV) panels, DG and energy storage (ES) is developed. The proposed model minimizes not only the operating cost, including fuel cost and purchasing cost, but also voltage deviations and power loss. The optimization model is based on the linearized sensitivity coefficients between state variables (e.g., node voltages) and control variables (e.g., real and reactive power injections of DG and ES). To avoid slow convergence when close to the optimum, a golden search method is introduced to control the step size and accelerate the convergence. The proposed algorithm is demonstrated on modified IEEE 13 nodes test feeders with multiple PV panels, DG and ES. Numerical simulation results validate the proposed algorithm. Various scenarios of system configuration are studied and some critical findings are concluded.

  1. Energy storage in irradiating rock salt

    International Nuclear Information System (INIS)

    Kaschenz, H.; Noack, W.; Runge, K.; Koerner, W.

    1980-01-01

    In order to determine both the amount of energy stored by the effect of ionizing radiation on rock salt and the conditions of its release, light absorption spectroscopy and differential thermo-analysis have been used for investigating rock salt samples irradiated with 60 Co. Within the investigated energy dose range from 1 . 10 6 Gy to 5 . 10 7 Gy the amount of stored energy was between 0.12 and 1.5 kJ/kg. The main portion of stored energy is released by heating to temperatures ranging from 200 to 350 0 C. It is considered that the energy stored in rock salt does not cause any danger in the ultimate storage of radioactive wastes. (author)

  2. Multifunctional Energy Storage and Conversion Devices.

    Science.gov (United States)

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

    2016-10-01

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

  3. A Numerical and Graphical Review of Energy Storage Technologies

    Directory of Open Access Journals (Sweden)

    Siraj Sabihuddin

    2014-12-01

    Full Text Available More effective energy production requires a greater penetration of storage technologies. This paper takes a looks at and compares the landscape of energy storage devices. Solutions across four categories of storage, namely: mechanical, chemical, electromagnetic and thermal storage are compared on the basis of energy/power density, specific energy/power, efficiency, lifespan, cycle life, self-discharge rates, capital energy/power costs, scale, application, technical maturity as well as environmental impact. It’s noted that virtually every storage technology is seeing improvements. This paper provides an overview of some of the problems with existing storage systems and identifies some key technologies that hold promise.

  4. Reluctance apparatus for flywheel energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Downers Grove, IL)

    2000-01-01

    A motor generator for providing high efficiency, controlled voltage output or storage of energy in a flywheel system. A motor generator includes a stator of a soft ferromagnetic material, a motor coil and a generator coil, and a rotor has at least one embedded soft ferromagnetic piece. Control of voltage output is achieved by use of multiple stator pieces and multiple rotors with controllable gaps between the stator pieces and the soft ferromagnetic piece.

  5. Designing a cost-effective CO2 storage infrastructure using a GIS based linear optimization energy model

    NARCIS (Netherlands)

    Broek, M. van den; Brederode, E.; Ramírez, A.; Kramers, L.; Kuip, M. van der; Wildenborg, T.; Turkenburg, W.; Faaij, A.

    2010-01-01

    Large-scale deployment of carbon capture and storage needs a dedicated infrastructure. Planning and designing of this infrastructure require incorporation of both temporal and spatial aspects. In this study, a toolbox has been developed that integrates ArcGIS, a geographical information system with

  6. Merits of flywheels for spacecraft energy storage

    Science.gov (United States)

    Gross, S.

    1984-01-01

    Flywheel energy storage systems which have a very good potential for use in spacecraft are discussed. This system can be superior to alkaline secondary batteries and regenerable fuel cells in most of the areas that are important in spacecraft applications. Of special importance, relative to batteries, are lighter weight, longer cycle and operating life, and high efficiency which minimizes solar array size and the amount of orbital makeup fuel required. Flywheel systems have a long shelf life, give a precise state of charge indication, have modest thermal control needs, are capable of multiple discharges per orbit, have simple ground handling needs, and have characteristics which would be useful for military applications. The major disadvantages of flywheel energy storage systems are that: power is not available during the launch phase without special provisions; and in flight failure of units may force shutdown of good counter rotating units, amplifying the effects of failure and limiting power distribution system options; no inherent emergency power capability unless specifically designed for, and a high level of complexity compared with batteries. The potential advantages of the flywheel energy storage system far outweigh the disadvantages.

  7. Flight experiment of thermal energy storage

    Science.gov (United States)

    Namkoong, David

    1989-01-01

    Thermal energy storage (TES) enables a solar dynamic system to deliver constant electric power through periods of sun and shade. Brayton and Stirling power systems under current considerations for missions in the near future require working fluid temperatures in the 1100 to 1300+ K range. TES materials that meet these requirements fall into the fluoride family of salts. These salts store energy as a heat of fusion, thereby transferring heat to the fluid at constant temperature during shade. The principal feature of fluorides that must be taken into account is the change in volume that occurs with melting and freezing. Salts shrink as they solidify, a change reaching 30 percent for some salts. The location of voids that form as result of the shrinkage is critical when the solar dynamic system reemerges into the sun. Hot spots can develop in the TES container or the container can become distorted if the melting salt cannot expand elsewhere. Analysis of the transient, two-phase phenomenon is being incorporated into a three-dimensional computer code. The code is capable of analysis under microgravity as well as 1 g. The objective of the flight program is to verify the predictions of the code, particularly of the void location and its effect on containment temperature. The four experimental packages comprising the program will be the first tests of melting and freezing conducted under microgravity. Each test package will be installed in a Getaway Special container to be carried by the shuttle. The package will be self-contained and independent of shuttle operations other than the initial opening of the container lid and the final closing of the lid. Upon the return of the test package from flight, the TES container will be radiographed and finally partitioned to examine the exact location and shape of the void. Visual inspection of the void and the temperature data during flight will constitute the bases for code verification.

  8. Energy in buildings: Efficiency, renewables and storage

    Directory of Open Access Journals (Sweden)

    Koebel Matthias M.

    2017-01-01

    Full Text Available This lecture summary provides a short but comprehensive overview on the “energy and buildings” topic. Buildings account for roughly 40% of the global energy demands. Thus, an increased adoption of existing and upcoming materials and solutions for the building sector represents an enormous potential to reduce building related energy demands and greenhouse gas emissions. The central question is how the building envelope (insulation, fenestration, construction style, solar control affects building energy demands. Compared to conventional insulation materials, superinsulation materials such as vacuum insulation panels and silica aerogel achieve the same thermal performance with significantly thinner insulation layers. With low-emissivity coatings and appropriate filler gasses, double and triple glazing reduce thermal losses by up to an order of magnitude compared to old single pane windows, while vacuum insulation and aerogel filled glazing could reduce these even further. Electrochromic and other switchable glazing solutions maximize solar gains during wintertime and minimize illumination demands whilst avoiding overheating in summer. Upon integration of renewable energy systems into the building energy supply, buildings can become both producers and consumers of energy. Combined with dynamic user behavior, temporal variations in the production of renewable energy require appropriate storage solutions, both thermal and electrical, and the integration of buildings into smart grids and energy district networks. The combination of these measures allows a reduction of the existing building stock by roughly a factor of three —a promising, but cost intensive way, to prepare our buildings for the energy turnaround.

  9. Energy in buildings: Efficiency, renewables and storage

    Science.gov (United States)

    Koebel, Matthias M.

    2017-07-01

    This lecture summary provides a short but comprehensive overview on the "energy and buildings" topic. Buildings account for roughly 40% of the global energy demands. Thus, an increased adoption of existing and upcoming materials and solutions for the building sector represents an enormous potential to reduce building related energy demands and greenhouse gas emissions. The central question is how the building envelope (insulation, fenestration, construction style, solar control) affects building energy demands. Compared to conventional insulation materials, superinsulation materials such as vacuum insulation panels and silica aerogel achieve the same thermal performance with significantly thinner insulation layers. With low-emissivity coatings and appropriate filler gasses, double and triple glazing reduce thermal losses by up to an order of magnitude compared to old single pane windows, while vacuum insulation and aerogel filled glazing could reduce these even further. Electrochromic and other switchable glazing solutions maximize solar gains during wintertime and minimize illumination demands whilst avoiding overheating in summer. Upon integration of renewable energy systems into the building energy supply, buildings can become both producers and consumers of energy. Combined with dynamic user behavior, temporal variations in the production of renewable energy require appropriate storage solutions, both thermal and electrical, and the integration of buildings into smart grids and energy district networks. The combination of these measures allows a reduction of the existing building stock by roughly a factor of three —a promising, but cost intensive way, to prepare our buildings for the energy turnaround.

  10. Innovative Business Cases for Energy Storage In a Restructured Electricity Marketplace, A Study for the DOE Energy Storage Systems Program

    Energy Technology Data Exchange (ETDEWEB)

    IANNUCCI, JOE; EYER, JIM; BUTLER, PAUL C.

    2003-02-01

    This report describes the second phase of a project entitled ''Innovative Business Cases for Energy Storage in a Restructured Electricity Marketplace''. During part one of the effort, nine ''Stretch Scenarios'' were identified. They represented innovative and potentially significant uses of electric energy storage. Based on their potential to significantly impact the overall energy marketplace, the five most compelling scenarios were identified. From these scenarios, five specific ''Storage Market Opportunities'' (SMOs) were chosen for an in-depth evaluation in this phase. The authors conclude that some combination of the Power Cost Volatility and the T&D Benefits SMOs would be the most compelling for further investigation. Specifically, a combination of benefits (energy, capacity, power quality and reliability enhancement) achievable using energy storage systems for high value T&D applications, in regions with high power cost volatility, makes storage very competitive for about 24 GW and 120 GWh during the years of 2001 and 2010.

  11. A Distributed Control Strategy Based on DC Bus Signaling for Modular Photovoltaic Generation Systems With Battery Energy Storage

    DEFF Research Database (Denmark)

    Sun, Kai; Zhang, Li; Xing, Yan

    2011-01-01

    Modular generation system, which consists of modular power conditioning converters, is an effective solution to integrate renewable energy sources with conventional utility grid to improve reliability and efficiency, especially for photovoltaic generation. A distributed control strategy based...... charging/discharging and local loads, which is available of either grid-connected operation or islanding operation. By using the proposed control strategy, the operations of a modular PV generation system are categorized into four modes: islanding with battery discharging, grid-connected rectification......, grid-connected inversion, and islanding with constant voltage (CV) generation.The power balance of the system under extreme conditions such as the islanding operation with a full-charged battery is taken into account in this control strategy. The dc bus voltage level is employed as an information...

  12. 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

  13. A design of cascade control system and adaptive load compensator for battery/ultracapacitor hybrid energy storage-based direct current microgrid

    International Nuclear Information System (INIS)

    Pavković, Danijel; Lobrović, Mihael; Hrgetić, Mario; Komljenović, Ante

    2016-01-01

    Highlights: • Battery/ultracapacitor storage is considered for a direct-current microgrid. • Microgrid voltage cascade control system with load compensator is designed. • Current references are allocated so that ultracapacitor takes on transient loads. • Adaptive Kalman filter-based estimator is used for indirect load compensation. • Control strategy has been verified on a downscaled hardware-in-the-loop setup. - Abstract: A control system design based on an actively-controlled battery/ultracapacitor hybrid energy storage system suitable for direct current microgrid energy management purposes is presented in this paper. The proposed cascade control system arrangement is based on the superimposed proportional–integral voltage controller designed according to Damping Optimum criterion and a zero-pole canceling feed-forward load compensator aimed at voltage excursion suppression under variable load conditions. The superimposed controller commands the inner battery and ultracapacitor current control loops through a dynamic current reference distribution scheme, wherein the ultracapacitor takes on the highly-dynamic (transient) current demands, and the battery covers for steady-state loads. In order to avoid deep discharges of the ultracapacitor module, it is equipped with an auxiliary state-of-charge controller. Finally, for those applications where load is not measured, an adaptive Kalman filter-based load compensator is proposed and tested. The presented control strategy has been implemented on the low-cost industrial controller unit, and its effectiveness has been verified by means of simulations and experiments for the cases of abrupt load changes and quasi-stochastic load profiles using a downscaled battery/ultracapacitor hardware-in-the-loop experimental setup.

  14. Economic Modeling of Compressed Air Energy Storage

    Directory of Open Access Journals (Sweden)

    Rui Bo

    2013-04-01

    Full Text Available Due to the variable nature of wind resources, the increasing penetration level of wind power will have a significant impact on the operation and planning of the electric power system. Energy storage systems are considered an effective way to compensate for the variability of wind generation. This paper presents a detailed production cost simulation model to evaluate the economic value of compressed air energy storage (CAES in systems with large-scale wind power generation. The co-optimization of energy and ancillary services markets is implemented in order to analyze the impacts of CAES, not only on energy supply, but also on system operating reserves. Both hourly and 5-minute simulations are considered to capture the economic performance of CAES in the day-ahead (DA and real-time (RT markets. The generalized network flow formulation is used to model the characteristics of CAES in detail. The proposed model is applied on a modified IEEE 24-bus reliability test system. The numerical example shows that besides the economic benefits gained through energy arbitrage in the DA market, CAES can also generate significant profits by providing reserves, compensating for wind forecast errors and intra-hour fluctuation, and participating in the RT market.

  15. Thermal Energy Storage with Phase Change Material

    Directory of Open Access Journals (Sweden)

    Lavinia Gabriela SOCACIU

    2012-08-01

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

  16. CALORSTOCK'94. Thermal energy storage. Better economy, environment, technology

    International Nuclear Information System (INIS)

    Kangas, M.T.; Lund, P.D.

    1994-01-01

    This publication is the first volume of the proceedings of CALORSTOCK'94, the sixth international conference on thermal energy storage held in Espoo, Finland on August 22-25, 1994. This volume contains 58 presentations from the following six sessions: Aquifer storage, integration into energy systems, Simulation models and design tools, IEA energy conservation through energy storage programme workshop, Earth coupled storage, District heating and utilities

  17. Impacts of compressed air energy storage plant on an electricity market with a large renewable energy portfolio

    International Nuclear Information System (INIS)

    Foley, A.; Díaz Lobera, I.

    2013-01-01

    Renewable energy generation is expected to continue to increase globally due to renewable energy targets and obligations to reduce greenhouse gas emissions. Some renewable energy sources are variable power sources, for example wind, wave and solar. Energy storage technologies can manage the issues associated with variable renewable generation and align non-dispatchable renewable energy generation with load demands. Energy storage technologies can play different roles in each of the step of the electric power supply chain. Moreover, large scale energy storage systems can act as renewable energy integrators by smoothing the variability. Compressed air energy storage is one such technology. This paper examines the impacts of a compressed air energy storage facility in a pool based wholesale electricity market in a power system with a large renewable energy portfolio

  18. Investigation of lithium sulphate for high temperature thermal energy storage

    Science.gov (United States)

    Bayon, Alicia; Liu, Ming; Bruno, Frank; Hinkley, Jim

    2017-06-01

    Lithium sulphate (Li2SO4) was evaluated as a solid-solid PCM material to be coupled with concentrated solar power (CSP) technologies. The energy is stored in a cubic crystalline phase that is formed at temperatures above 576°C and can potentially be discharged at temperatures as low as 150°C, providing both sensible and latent thermal energy storage in a hybrid sensible-latent system. These operational conditions are appropriate for current CSP technologies based on subcritical steam Rankine power cycles. Results from thermal cycling experiments in air showed no change in energy storage capacity after 15 cycles. There was up to a 5% reduction in latent thermal capacity and 0.95% in total thermal capacity after 150 cycles in air. In our paper, we evaluate a hybrid sensible-latent thermal energy storage system based on lithium sulphate from an economic and technical performance point of view, demonstrating its potential as a high temperature thermal energy storage material.

  19. Characterization and assessment of novel bulk storage technologies : a study for the DOE Energy Storage Systems program.

    Energy Technology Data Exchange (ETDEWEB)

    Huff, Georgianne; Tong, Nellie (KEMA Consulting, Fairfax, VA); Fioravanti, Richard (KEMA Consulting, Fairfax, VA); Gordon, Paul (Sentech/SRA International, Bethesda, MD); Markel, Larry (Sentech/SRA International, Bethesda, MD); Agrawal, Poonum (Sentech/SRA International, Bethesda, MD); Nourai, Ali (KEMA Consulting, Fairfax, VA)

    2011-04-01

    This paper reports the results of a high-level study to assess the technological readiness and technical and economic feasibility of 17 novel bulk energy storage technologies. The novel technologies assessed were variations of either pumped storage hydropower (PSH) or compressed air energy storage (CAES). The report also identifies major technological gaps and barriers to the commercialization of each technology. Recommendations as to where future R&D efforts for the various technologies are also provided based on each technology's technological readiness and the expected time to commercialization (short, medium, or long term). The U.S. Department of Energy (DOE) commissioned this assessment of novel concepts in large-scale energy storage to aid in future program planning of its Energy Storage Program. The intent of the study is to determine if any new but still unproven bulk energy storage concepts merit government support to investigate their technical and economic feasibility or to speed their commercialization. The study focuses on compressed air energy storage (CAES) and pumped storage hydropower (PSH). It identifies relevant applications for bulk storage, defines the associated technical requirements, characterizes and assesses the feasibility of the proposed new concepts to address these requirements, identifies gaps and barriers, and recommends the type of government support and research and development (R&D) needed to accelerate the commercialization of these technologies.

  20. Redox flow cell energy storage systems

    Science.gov (United States)

    Thaller, L. H.

    1979-01-01

    NASA-Redox systems are electrochemical storage devices that use two fully soluble Redox couples, anode and cathode fluids, as active electrode materials separated by a highly selective ion exchange membrane. The reactants are contained in large storage tanks and pumped through a stack of Redox flow cells where the electrochemical reactions (reduction and oxidation) take place at porous carbon felt electrodes. A string or stack of these power producing cells is connected in series in a bipolar manner. Redox energy storage systems promise to be inexpensive and possess many features that provide for flexible design, long life, high reliability and minimal operation and maintenance costs. These features include independent sizing of power and storage capacity requirements and inclusion within the cell stack of a cell that monitors the state of charge of the system as a whole, and a rebalance cell which permits continuous correction to be made for minor side reactions that would tend to result in the anode fluid and cathode fluids becoming electrochemically out of balance. These system features are described and discussed.