WorldWideScience

Sample records for based energy storage

  1. 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.

  2. 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.)

  3. 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…

  4. Graphene and graphene-based materials for energy storage applications.

    Science.gov (United States)

    Zhu, Jixin; Yang, Dan; Yin, Zongyou; Yan, Qingyu; Zhang, Hua

    2014-09-10

    With the increased demand in energy resources, great efforts have been devoted to developing advanced energy storage and conversion systems. Graphene and graphene-based materials have attracted great attention owing to their unique properties of high mechanical flexibility, large surface area, chemical stability, superior electric and thermal conductivities that render them great choices as alternative electrode materials for electrochemical energy storage systems. This Review summarizes the recent progress in graphene and graphene-based materials for four energy storage systems, i.e., lithium-ion batteries, supercapacitors, lithium-sulfur batteries and lithium-air batteries.

  5. 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

  6. Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Mukundan, Rangachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-30

    Energy storage technology is critical if the U.S. is to achieve more than 25% penetration of renewable electrical energy, given the intermittency of wind and solar. Energy density is a critical parameter in the economic viability of any energy storage system with liquid fuels being 10 to 100 times better than batteries. However, the economical conversion of electricity to fuel still presents significant technical challenges. This project addressed these challenges by focusing on a specific approach: efficient processes to convert electricity, water and nitrogen to ammonia. Ammonia has many attributes that make it the ideal energy storage compound. The feed stocks are plentiful, ammonia is easily liquefied and routinely stored in large volumes in cheap containers, and it has exceptional energy density for grid scale electrical energy storage. Ammonia can be oxidized efficiently in fuel cells or advanced Carnot cycle engines yielding water and nitrogen as end products. Because of the high energy density and low reactivity of ammonia, the capital cost for grid storage will be lower than any other storage application. This project developed the theoretical foundations of N2 catalysis on specific catalysts and provided for the first time experimental evidence for activation of Mo 2N based catalysts. Theory also revealed that the N atom adsorbed in the bridging position between two metal atoms is the critical step for catalysis. Simple electrochemical ammonia production reactors were designed and built in this project using two novel electrolyte systems. The first one demonstrated the use of ionic liquid electrolytes at room temperature and the second the use of pyrophosphate based electrolytes at intermediate temperatures (200 – 300 ºC). The mechanism of high proton conduction in the pyrophosphate materials was found to be associated with a polyphosphate second phase contrary to literature claims and ammonia production rates as high as 5X 10

  7. 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 energy storage systems because of their unique physicochemical properties, such as conductivity, mechanical and thermal stability, and cyclability. In this review, we aim to provide a systematic summary of the synthesis, modification, and electrochemical performance of 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.

  8. 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.

  9. 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

  10. Enhanced electrophoretic motion using supercapacitor-based energy storage system.

    Science.gov (United States)

    Liu, Ran; Wong, Flory; Duan, Wentao; Sen, Ayusman

    2013-12-23

    Electrophoretic motion at low potentials is facilitated by redox chemistry occurring in a supercapacitor-based electrochemical energy storage system during charge and discharge. We show that MnO2 -modified electrodes can effectively alleviate the electrode surface polarization, the main factor that leads to inefficient electrophoresis at low voltages. A self-powered electrophoretic system based on a discharging battery has been also fabricated.

  11. 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.

  12. 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.

  13. Bismuth pyrochlore-based thin films for dielectric energy storage

    Science.gov (United States)

    Michael, Elizabeth K.

    The drive towards the miniaturization of electronic devices has created a need for dielectric materials with large energy storage densities. These materials, which are used in capacitors, are a critical component in many electrical systems. Here, the development of dielectric energy storage materials for pulsed power applications, which require materials with the ability to accumulate a large amount of energy and then deliver it to the system rapidly, is explored. The amount of electrostatic energy that can be stored by a material is a function of the induced polarization and the dielectric breakdown strength of the material. An ideal energy storage dielectric would possess a high relative permittivity, high dielectric breakdown strength, and low loss tangent under high applied electric fields. The bismuth pyrochlores are a compositionally tunable family of materials that meet these requirements. Thin films of cubic pyrochlore bismuth zinc niobate, bismuth zinc tantalate, and bismuth zinc niobate tantalate, were fabricated using a novel solution chemistry based upon the Pechini method. This solution preparation is advantageous because it avoids the use of teratogenic solvents, such as 2-methoxyethanol. Crystalline films fabricated using this solution chemistry had very small grains that were approximately 27 nm in lateral size and 35 nm through the film thickness. Impedance measurements found that the resistivity of the grain boundaries was two orders of magnitude higher than the resistivity of the grain interior. The presence of many resistive grain boundaries impeded conduction through the films, resulting in high breakdown strengths for these materials. In addition to high breakdown strengths, this family of materials exhibited moderate relative permittivities of between 55 +/- 2 and 145 +/- 5, for bismuth zinc tantalate and bismuth zinc niobate, respectively, and low loss tangents on the order of 0.0008 +/- 0.0001. Increases in the concentration of the tantalum

  14. Technology Base Research Project for electrochemical energy storage

    Science.gov (United States)

    Kinoshita, K.

    1985-06-01

    The DOE Electrochemical Energy Storage Program is divided into two projects: (1) the exploratory technology development and testing (ETD) project and (2) the technology base research (TBR) project. The role of the TBR Project is to perform supporting research for the advanced battery systems under development by the ETD Project, and to evaluate new systems with potentially superior performance, durability and/or cost characteristics. The specific goal of the TBR Project is to identify the most promising electrochemical technologies and transfer them to industry and/or the ETD Project for further development and scale-up. This report summarizes the research, financial, and management activities relevant to the TBR Project in CY 1984. General problem areas addressed by the project include identification of new electrochemical couples for advanced batteries, determination of technical feasibility of the new couples, improvements in battery components and materials, establishment of engineering principles applicable to electrochemical energy storage and conversion, and the assessment of fuel-cell technology for transportation applications. Major emphasis is given to applied research which will lead to superior performance and lower life-cycle costs. The TBR Project is divided into three major project elements: exploratory research, applied science research, and air systems research.

  15. Boron-Based Layered Structures for Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y.; Wei, S. H.

    2012-01-01

    Based on Density Functional Theory simulations, we have studied the boron-based graphite-like materials, i.e., LiBC and MgB2 for energy storage. First, when half of the Li-ions in the LiBC are removed, the BC layered structure is still preserved. The Li intercalation potential (equilibrium lithium-insertion voltage of 2.3-2.4 V relative to lithium metal) is significantly higher than that in graphite, allowing Li0.5BC to function as a cathode material. The reversible electrochemical reaction, LiBC = Li0.5BC + 0.5Li, enables a specific energy density of 1088 Wh/kg and a volumetric energy density of 2463 Wh/L. Second, 75% of the Mg ions in MgB2 can be removed and reversibly inserted with the layered boron structures being preserved through an in-plane topological transformation between the hexagonal lattice domains and triangular domains. The mechanism of such a charge-driven transformation originates from the versatile valence state of boron in its planar form.

  16. Lignin Based Carbon Materials for Energy Storage Applications

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Sabornie [ORNL; Saito, Tomonori [ORNL; Rios, Orlando [ORNL; Johs, Alexander [ORNL

    2014-01-01

    The implementation of Li-ion battery technology into electric and hybrid electric vehicles and portable electronic devices such as smart phones, laptops and tablets, creates a demand for efficient, economic and sustainable materials for energy storage. However, the high cost and long processing time associated with manufacturing battery-grade anode and cathode materials are two big constraints for lowering the total cost of batteries and environmentally friendly electric vehicles. Lignin, a byproduct of the pulp and paper industry and biorefinery, is one of the most abundant and inexpensive natural biopolymers. It can be efficiently converted to low cost carbon fibers with optimal properties for use as anode materials. Recent developments in the preparation of lignin precursors and conversion to carbon fiber-based anode materials have created a new class of anode materials with excellent electrochemical characteristics suitable for immediate use in existing Li- or Na-ion battery technologies.

  17. Thermal energy storage. Citations from the NTIS data base

    Science.gov (United States)

    Cavagnaro, D. M.

    1980-09-01

    The cited reports of federally-funded research concern thermal energy storage. The citations cover the design of equipment, performance evaluation, theory, materials used, and experimental design. This updated bibliography contains 240 citations, 128 of which are new entries to the previous edition.

  18. Energy Storage System Based on Cascaded Multilevel Inverter with Decoupled Energy Balancing Control

    Directory of Open Access Journals (Sweden)

    Cao Yuanzhi

    2015-01-01

    Full Text Available This paper presents a three phase cascaded multilevel inverter based supercapacitor (SC energy storage system with novel structure and control strategy to maintain the energy balance of between phases. Every two phases are coupled with a series LC filter. With the filter, SC cells in different phases could exchange energy with an auxiliary power flow at high frequency. The auxiliary power flow is orthogonal to the primary power flow. The phase difference between high frequency voltage and current components of each phase determines whether the energy is absorbed into or released from its SC cells. Unlike traditional energy balancing strategies, the proposed method is independent to the fundamental real power drawn by the energy storage system. Simulation results confirmed the effects of proposed theories.

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

    OpenAIRE

    Zhang, Jintao; Xia, Zhenhai; Dai, Liming

    2015-01-01

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

  20. 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.

  1. Superconducting magnetic energy storage

    International Nuclear Information System (INIS)

    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

  2. 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...

  3. Electrochemical Energy Storage Branch

    Science.gov (United States)

    1985-01-01

    The activities of the Electrochemical Energy Storage Branch are highlighted, including the Technology Base Research and the Exploratory Technology Development and Testing projects within the Electrochemical Energy Storage Program for the 1984 fiscal year. General Headquarters activities are presented first; and then, a summary of the Director Controlled Milestones, followed by other major accomplishments. A listing of the workshops and seminars held during the year is also included.

  4. Technology Base Research Project for electrochemical energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Kim (ed.)

    1991-06-01

    The US DOE's Office of Propulsion Systems provides support for an electrochemical energy storage program, which includes R D on advanced rechargeable batteries and fuel cells. A major goal of this program is to develop electrochemical power sources suitable for application in electric vehicles (EVs). The program centers on advanced systems that offer the potential for high performance and low life-cycle costs, both of which are necessary to permit significant penetration into commercial markets. The general R D areas addressed by the project include identification of new electrochemical couples for advanced batteries, determination of technical feasibility of the new couples, improvements in battery components and materials, establishment of engineering principles applicable to electrochemical energy storage and conversion, and the development of air-system (fuel cell, metal/air) technology for transportation applications. Major emphasis is given to applied research which will lead to superior performance and lower life-cycle costs. The TBR Project is divided into three major project elements: Exploratory Research, Applied Science Research, and Air Systems Research. Highlights of each project element are summarized according to the appropriate battery system or electrochemical research area. 16 figs., 4 tabs.

  5. 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...

  6. 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.

  7. 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...

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

    Science.gov (United States)

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

    2016-08-01

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

  9. A solar receiver-storage modular cascade based on porous ceramic structures for hybrid sensible/thermochemical solar energy storage

    Science.gov (United States)

    Agrafiotis, Christos; de Oliveira, Lamark; Roeb, Martin; Sattler, Christian

    2016-05-01

    The current state-of-the-art solar heat storage concept in air-operated Solar Tower Power Plants is to store the solar energy provided during on-sun operation as sensible heat in porous solid materials that operate as recuperators during off-sun operation. The technology is operationally simple; however its storage capacity is limited to 1.5 hours. An idea for extending this capacity is to render this storage concept from "purely" sensible to "hybrid" sensible/ thermochemical one, via coating the porous heat exchange modules with oxides of multivalent metals for which their reduction/oxidation reactions are accompanied by significant heat effects, or by manufacturing them entirely of such oxides. In this way solar heat produced during on-sun operation can be used (in addition to sensibly heating the porous solid) to power the endothermic reduction of the oxide from its state with the higher metal valence to that of the lower; the thermal energy can be entirely recovered by the reverse exothermic oxidation reaction (in addition to sensible heat) during off-sun operation. Such sensible and thermochemical storage concepts were tested on a solar-irradiated receiver- heat storage module cascade for the first time. Parametric studies performed so far involved the comparison of three different SiC-based receivers with respect to their capability of supplying solar-heated air at temperatures sufficient for the reduction of the oxides, the effect of air flow rate on the temperatures achieved within the storage module, as well as the comparison of different porous storage media made of cordierite with respect to their sensible storage capacity.

  10. Optimal combination of energy storages for prospective power supply systems based on Renewable Energy Sources

    CERN Document Server

    Weitemeyer, Stefan; Siemer, Lars; Agert, Carsten

    2016-01-01

    Prospective power supply systems based on Renewable Energy Sources require measures to balance power generation and load at all times. The utilisation of storage devices and backup power plants is widely suggested for this purpose, whereas the best combination is still to be found. In this work, we present a modelling approach to systematically study scenarios of future power supply systems with a high share of electricity originating from wind and solar resources. By considering backup as a subordinate source of electricity with energy-only costs, the approach is independent of the actual full-load hours of the backup power plants. Applying the approach to multi-year meteorological data for Germany, cost-optimised combinations of storage devices and backup power are identified. We find that even in scenarios with significant excess generation capacities there is a need for storage devices or backup power plants with discharging power on the same order as the average load to balance the system at all times. F...

  11. 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.

  12. 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.

  13. 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.

  14. 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.)

  15. 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...

  16. GA -based energy management optimization for grid-connected photovoltaic system without battery storage

    International Nuclear Information System (INIS)

    This paper presents genetic algorithm (GA) based optimization of energy management for grid connected photovoltaic (PV) systems without battery storage. The major objective of this work is to minimize energy cost by maximizing objective function of GA considering both energy consumption and generation. In objective function calculation, PV module output power obtained by model of PV modules and previous power recordings from the PV system were employed. In the system, some electrical appliances and lights are in the energy consumption side and photovoltaic energy source connected to the grid is in the energy generation side. A simulation study was implemented to obtain energy cost savings using GA optimization in a commercial building. Due to the cost of the batteries, PV system is implemented without battery storage. Therefore, by adapting fluctuating PV energy generation with the time -flexible loads , an effort was aimed to develop a smart -grid strategy. Key words: energy management , PV system, genetic algorithms, optimization, load scheduling

  17. Single-fiber-based hybridization of energy converters and storage units using graphene as electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Joonho; Lee, Minbaek; Wang, Zhong Lin [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA (United States); Park, Young Jun; Cha, Seung Nam; Kim, Jong Min [Frontier Research Lab, Samsung Advanced Institute of Technology, Samsung Electronics, Gyeonggi-Do (Korea, Republic of); Choi, Young Jin [Department of Physics, MyongJi University, Yongin (Korea, Republic of); Department of Nano Science and Engineering, MyongJi University, Yongin (Korea, Republic of); Lee, Churl Seung [Energy Nanomaterials Research Center, Korea Electronics Technology Institute, 68 Yatap-dong, Bundang-gu, Seongnam-si, Gyeonggi-do (Korea, Republic of)

    2011-08-09

    The first integration of multiple energy harvesters and a storage device along single fiber using ZnO nanowires (NWs) and graphenes as the basic materials is reported. This energy generation and storage device allows simultaneous harvesting of solar and mechanical energy. The unique architecture of fiber-based electrodes and use of ZnO NWs, and graphenes as active material and electrodes could be useful for the future development of flexible and wearable electronics. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

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

    DEFF Research Database (Denmark)

    You, Shi; Hu, Junjie; Lin, Jin

    2016-01-01

    Hydrogen as an energy carrier represents one of the most promising carbon-free energy solutions. The ongoing development of power-to-gas (PtG) technologies that supports large-scale utilization of hydrogen is therefore expected to support hydrogen economy with a final breakthrough. In this paper......, the economic performance of a MW-sized hydrogen system, i.e. a composition of water electrolysis, hydrogen storage, and fuel cell combined heat and power plant (FCCHP), is assessed as an example of hydrogen-based bidirectional electrical energy storage (EES). The analysis is conducted in view of the Danish...

  19. 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.

  20. Terrestrial Energy Storage SPS Systems

    Science.gov (United States)

    Brandhorst, Henry W., Jr.

    1998-01-01

    Terrestrial energy storage systems for the SSP system were evaluated that could maintain the 1.2 GW power level during periods of brief outages from the solar powered satellite (SPS). Short-term outages of ten minutes and long-term outages up to four hours have been identified as "typical" cases where the ground-based energy storage system would be required to supply power to the grid. These brief interruptions in transmission could result from performing maintenance on the solar power satellite or from safety considerations necessitating the power beam be turned off. For example, one situation would be to allow for the safe passage of airplanes through the space occupied by the beam. Under these conditions, the energy storage system needs to be capable of storing 200 MW-hrs and 4.8 GW-hrs, respectively. The types of energy storage systems to be considered include compressed air energy storage, inertial energy storage, electrochemical energy storage, superconducting magnetic energy storage, and pumped hydro energy storage. For each of these technologies, the state-of-the-art in terms of energy and power densities were identified as well as the potential for scaling to the size systems required by the SSP system. Other issues addressed included the performance, life expectancy, cost, and necessary infrastructure and site locations for the various storage technologies.

  1. Intelligent Control of Battery Energy Storage for Multi-Agent Based Microgrid Energy Management

    Directory of Open Access Journals (Sweden)

    Sung-Soo Hong

    2013-09-01

    Full Text Available Microgrids can be considered as controllable units from the utility point of view because the entities of microgrids such as distributed energy resources and controllable loads can effectively control the amount of power consumption or generation. Therefore, microgrids can make various contracts with utility companies such as demand response program or ancillary services. Another advantage of microgrids is to integrate renewable energy resources to low-voltage distribution networks. Battery energy storage systems (BESSs can effectively compensate the intermittent output of renewable energy resources. This paper presents intelligent control schemes for BESSs and autonomous energy management schemes of microgrids based on the concept of multi-agent systems. The proposed control scheme consists of two layers of decision-making procedures. In the bottom layer, intelligent agents decide the optimal operation strategies of individual microgrid entities such as BESSs, backup generators and loads. In the upper layer, the central microgrid coordinator (MGCC coordinates multiple agents so that the overall microgrid can match the load reduction requested by the grid operator. The proposed control scheme is applied to Korea Power Exchange’s Intelligent Demand Response Program.

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

    Directory of Open Access Journals (Sweden)

    Harika G,

    2014-04-01

    Full Text Available 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 simulation of dual inverter based Wind energy system starts with wind turbine coupled PMSG which is connected to three phase diode rectifier and Boost converter which in-turn connected to a dual inverter which is used to deliver the wind energy to grid and also to store the energy in energy storage systems during surplus periods. Also Short term power fluctuations are mitigated and harmonics are reduced. Maximum Power point Tracking (MPPT method, Energy storage system interfacing is also studied. The overall system model is designed and simulated by using MATLAB/SIMULINK.

  3. 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.

  4. Modeling mechanical energy storage in springs based on carbon nanotubes

    International Nuclear Information System (INIS)

    A modeling study of the potential for storing energy in the elastic deformation of springs comprised of carbon nanotubes (CNTs) is presented. Analytic models were generated to estimate the ideal achievable energy density in CNTs subject to axial tension, compression, bending and torsion, taking into account limiting mechanisms such as the strength of individual CNTs, the onset of buckling, and the packing density limitations of CNT groupings. The stored energy density in CNT springs is predicted to be highest under tensile loading, with maximum values more than three orders of magnitude greater than the energy density of steel springs, and approximately eight times greater than the energy density of lithium-ion batteries. Densely packed bundles of precisely aligned, small diameter single-walled carbon nanotubes are identified as the best structure for high performance springs. The conceptual design and modeling of a portable electric power source that stores energy in a CNT spring are presented as tools for studying the potential performance of a system for generating electricity from the CNTs' stored mechanical energy.

  5. Mathematical Modelling-Based Energy System Operation Strategy Considering Energy Storage Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jun-Hyung; Hodge, Bri-Mathias

    2016-06-25

    Renewable energy resources are widely recognized as an alternative to environmentally harmful fossil fuels. More renewable energy technologies will need to penetrate into fossil fuel dominated energy systems to mitigate the globally witnessed climate changes and environmental pollutions. It is necessary to prepare for the potential problems with increased proportions of renewable energy in the energy system, to prevent higher costs and decreased reliability. Motivated by this need, this paper addresses the operation of an energy system with an energy storage system in the context of developing a decision-supporting framework.

  6. Control of Active Axial Magnetic Bearings for Flywheel-based Energy Storage System

    OpenAIRE

    Morís Gómez, Juan

    2014-01-01

    This thesis deals with the design and implementation of the control system for a Flywheel-based Energy Storage System (FESS) with active magnetic bearings. The thesis focuses on the construction of realistic model of the system according to experimental tests. The simulation model will be used to control the thrust magnetic bearings in order to withstand the flywheel in levitation.

  7. Energy Storage and Renewable Energy.

    OpenAIRE

    Durmaz, Tunç

    2014-01-01

    I consider an economy with fossil fuel and renewable energy and energy storage, and search for the conditions that lead to welfare improvements when energy is stored. I then solve for the optimal decision rule and analyze the long-run tendencies of the economy-energy variables. The findings are threefold. First, energy storage is fostered by the convexity of the marginal utility (prudence), the marginal cost function for fossil fuel energy, and the degree of intermittency. Second, considering...

  8. Improvement of Borehole Thermal Energy Storage Design Based on Experimental and Modelling Results

    OpenAIRE

    Lanini, Sandra; Delaleux, Fabien; Py, Xavier; Olivès, Régis; Nguyen, Denis

    2014-01-01

    Underground Thermal Energy Storage appears to be an attractive solution for solar thermal energy storage. The SOLARGEOTHERM research project aimed to evaluate the energetic potential of borehole thermal energy storage by means of a full-scale experimental device and heat transfer models. Analysis of the experimental data showed that a single borehole is not efficient for storage. Models showed that the heat transfer fluid in the geothermal probe lost 15 per cent of its energy at a depth of 10...

  9. 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

  10. Flywheel Energy Storage Systems

    OpenAIRE

    Daoud, Mohammed; Abdel-Khalik, Ayman; Elserogi, Ahmed; Ahmed, Shehab; Massoud, Ahmed

    2015-01-01

    Flywheels are one of the oldest and most popular energy storage media owing to the simplicity of storing kinetic energy in a rotating mass. Flywheel energy storage systems (FESSs) can be used in different applications, for example, electric utilities and transportation. With the development of new technologies in the field of composite materials and magnetic bearings, higher energy densities are allowed in the design of flywheels. The amount of stored energy in FESS depends on the mass and th...

  11. Base-load solar thermal power using thermochemical energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Luzzi, A.; Lovegrove, K. [Australian National Univ., Canberra, ACT (Australia); Filippi, E. [Ammonia Casale, Lugano (Switzerland); Fricker, H. [FC Consulting, Rickenbach (Switzerland); Schmitz-Goeb, M. [L and C Steinmuller GmbH, Process Engineering Div., Gummersbach (Germany); Chandapillai, M. [Siemens Power Generation Asia Pacific Sdn, Bhd., Industrial Power Plants, Kuala Lumpur (Malaysia)

    1999-03-01

    Using a closed-loop thermochemical system based on the reversible ammonia reaction is one of the possible ways for building solar thermal power systems capable of providing electricity on a 24-hour basis without the need for any fossil fuel back-up. In a collaborative effort between industrial and academic partners from Australia, Switzerland, Germany and Malaysia, a study was undertaken to examine the techno-economic viability of this solar concept by formulating a preliminary design for a hypothetical 10 MW{sub e} demonstration system in Central Australia. It was found that a carefully designed demonstration solar power plant, which dominantly uses proven and standard materials, components and technologies, is likely to cost of the order of AUD 157 million and operate with a net solar-to-electric conversion efficiency of 18% and a capacity factor of 80%. This will result in leveled electricity costs (LEC) of about AUD 0.24 per kWh{sub e}. (authors)

  12. A new benzimidazole based covalent organic polymer having high energy storage capacity.

    Science.gov (United States)

    Patra, Bidhan C; Khilari, Santimoy; Satyanarayana, Lanka; Pradhan, Debabrata; Bhaumik, Asim

    2016-06-18

    We report the synthesis of a new benzimidazole-based covalent organic polymer (TpDAB) via solvothermal Schiff base condensation between 1,3,5-triformylphloroglucinol (Tp) and 3,3'-diaminobenzidine (DAB). TpDAB showed high energy storage capacity with a specific capacitance of 335 F g(-1) at 2 mV s(-1) scan rate and good cyclic stability with 93% retention of its initial specific capacitance after 1000 cycles. PMID:27222226

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

    Science.gov (United States)

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

    2016-07-01

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

  14. 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.

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

    Science.gov (United States)

    Lightcap, Ian V; Kamat, Prashant V

    2013-10-15

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

  16. 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.

  17. 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.

  18. Calcium-based multi-element chemistry for grid-scale electrochemical energy storage

    Science.gov (United States)

    Ouchi, Takanari; Kim, Hojong; Spatocco, Brian L.; Sadoway, Donald R.

    2016-01-01

    Calcium is an attractive material for the negative electrode in a rechargeable battery due to its low electronegativity (high cell voltage), double valence, earth abundance and low cost; however, the use of calcium has historically eluded researchers due to its high melting temperature, high reactivity and unfavorably high solubility in molten salts. Here we demonstrate a long-cycle-life calcium-metal-based rechargeable battery for grid-scale energy storage. By deploying a multi-cation binary electrolyte in concert with an alloyed negative electrode, calcium solubility in the electrolyte is suppressed and operating temperature is reduced. These chemical mitigation strategies also engage another element in energy storage reactions resulting in a multi-element battery. These initial results demonstrate how the synergistic effects of deploying multiple chemical mitigation strategies coupled with the relaxation of the requirement of a single itinerant ion can unlock calcium-based chemistries and produce a battery with enhanced performance. PMID:27001915

  19. Calcium-based multi-element chemistry for grid-scale electrochemical energy storage

    Science.gov (United States)

    Ouchi, Takanari; Kim, Hojong; Spatocco, Brian L.; Sadoway, Donald R.

    2016-03-01

    Calcium is an attractive material for the negative electrode in a rechargeable battery due to its low electronegativity (high cell voltage), double valence, earth abundance and low cost; however, the use of calcium has historically eluded researchers due to its high melting temperature, high reactivity and unfavorably high solubility in molten salts. Here we demonstrate a long-cycle-life calcium-metal-based rechargeable battery for grid-scale energy storage. By deploying a multi-cation binary electrolyte in concert with an alloyed negative electrode, calcium solubility in the electrolyte is suppressed and operating temperature is reduced. These chemical mitigation strategies also engage another element in energy storage reactions resulting in a multi-element battery. These initial results demonstrate how the synergistic effects of deploying multiple chemical mitigation strategies coupled with the relaxation of the requirement of a single itinerant ion can unlock calcium-based chemistries and produce a battery with enhanced performance.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-14

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

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

    Science.gov (United States)

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

    2011-09-14

    Graphene has attracted extensive research interest due to its strictly 2-dimensional (2D) structure, which results in its unique electronic, thermal, mechanical, and chemical properties and potential technical applications. These remarkable characteristics of graphene, along with the inherent benefits of a carbon material, make it a promising candidate for application in electrochemical energy devices. This article reviews the methods of graphene preparation, introduces the unique electrochemical behavior of graphene, and summarizes the recent research and development on graphene-based fuel cells, supercapacitors and lithium ion batteries. In addition, promising areas are identified for the future development of graphene-based materials in electrochemical energy conversion and storage systems. PMID:21799983

  2. 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.

  3. 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.

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

    Science.gov (United States)

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

    2016-08-14

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances the heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy. PMID:27430282

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

    OpenAIRE

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

    2016-01-01

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

  6. 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…

  7. Thermo-hydro-mechanical modeling and analysis of cement-based energy storages for small-scale dwellings

    Science.gov (United States)

    Hailemariam, Henok; Wuttke, Frank

    2016-04-01

    One of the common technologies for balancing the energy demand and supply in district heating, domestic hot water production, thermal power plants and thermal process industries in general is thermal energy storage. Thermal energy storage, in particular sensible heat storage as compared to latent heat storage and thermo-chemical storage, has recently gained much interest in the renewable energy storage sector due to its comparatively low cost and technical development. Sensible heat storages work on the principle of storing thermal energy by raising or lowering the temperature of liquid (commonly water) or solid media, and do not involve material phase change or conversion of thermal energy by chemical reactions or adsorption processes as in latent heat and thermo-chemical storages, respectively. In this study, the coupled thermo-hydro-mechanical behaviour of a cement-based thermal energy storage system for domestic applications has been modeled in both saturated as well as unsaturated conditions using the Finite Element method along with an extensive experimental analysis program for parameter detection. For this purpose, a prototype model is used with three well-known thermal energy storage materials, and the temperature and heat distribution of the system were investigated under specific thermo-hydro-mechanical conditions. Thermal energy samples with controlled water to solids ratio and stored in water for up to 28 days were used for the experimental program. The determination of parameters included: thermal conductivity, specific heat capacity and linear coefficient of thermal expansion (CTE) using a transient line-source measurement technique as well as a steady-state thermal conductivity and expansion meter; mechanical strength parameters such as uni-axial strength, young's modulus of elasticity, poisson's ratio and shear parameters using uniaxial, oedometer and triaxial tests; and hydraulic properties such as hydraulic permeability or conductivity under

  8. 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.

  9. 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.

  10. Energy storage device with large charge separation

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. 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.

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

    International Nuclear Information System (INIS)

    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

  13. Generalized Model of VSC-based Energy Storage Systems for Transient Stability Analysis

    OpenAIRE

    Ortega, Álvaro; Milano, Federico

    2015-01-01

    This paper presents a generalized energy storage system model for voltage and angle stability analysis. The proposed solution allows modeling most common energy storage technologies through a given set of linear differential algebraic equations (DAEs). In particular, the paper considers, but is not limited to, compressed air, superconducting magnetic, electrochemical capacitor and battery energy storage devices. While able to cope with a variety of different technologies, the proposed general...

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

    Directory of Open Access Journals (Sweden)

    Zhifeng Wang

    2015-04-01

    Full Text Available 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.

  15. 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.

  16. Nanostructured metal-oxide-conducting polymer based ultracapacitors for energy storage

    Science.gov (United States)

    Sidhu, Navjot Kaur

    investigations are focused on asymmetrical and three electrode ultracapacitors structures based on porous carbon and Pedot polymer composites. A wide variety of diagnostic techniques are used to evaluate the performance of ultracapacitors. Electrochemical measurements such as impedance spectroscopy, cyclic voltammetry, and galvanic charge discharge measurements were carried out for evaluation every electrode for use in the energy storage. Electrode morphology and structure characterization have been carried out using the X- ray diffraction, Raman spectroscopy, electron microscopy and transmission electron microscopy techniques.

  17. A GIS-based 3D online information system for underground energy storage in northern Germany

    Science.gov (United States)

    Nolde, Michael; Malte, Schwanebeck; Ehsan, Biniyaz; Rainer, Duttmann

    2015-04-01

    We would like to present the concept and current state of development of a GIS-based 3D online information system for underground energy storage. Its aim is to support the local 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 presented information system uses data of geological features such as rock layers, salt domes 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, powerline 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 process of pre-selecting sites suitable for energy storage. Not only the current situation but also prospective scenarios, such as expected growth in produced amount of energy are incorporated in the system. While the process of pre-selection 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, so that it can easily be utilized in any web browser. The results are visualized online as interactive 3d graphics. The information system is implemented in the Python programming language in combination with current Web standards, and is build using only free and open source software. It is being developed at Kiel University as part of the ANGUS+ project (lead by Prof. Sebastian Bauer) for the federal state of

  18. 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.

  19. 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.

  20. Planning for a 100% independent energy system based on smart energy storage for integration of renewables and CO2 emissions reduction

    International Nuclear Information System (INIS)

    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 Energy, Buildings as Positive Power Plants, Energy Storage and Smart grids in combination with Plug-in Vehicles. All these pillars must be supported by the use of smart energy storage. The results of previous research has shown that in order to increase security, efficiency and viability, there is need for energy storage, in primary or secondary form, in order to transfer energy surplus from period of excess to the period when there is a lack. The problem of today's storage systems is that they increase the cost of already expensive, distributed and renewable energy sources. That makes the large scale use of storage systems even less economically viable in market circumstances, despite economics of scale. The paper shows results of an energy planning methodology applied to several cases where use of smart energy storage system helps integration of energy flows, transformations and energy demand at the location of the energy end-use or close to it. Main results presented in this paper focus on planning a 100% independent energy system of Croatia. They also show the role of energy storage in a self-sustainable energy system with excess electricity production from renewable energy sources. The technical and financial analyses have been carried out for periods of one year taking into consideration demands and renewable energy production during all hours. - Highlights: → Smart use of energy storage will support four pillars of the Post Carbon Society. → RES in combination with energy storage may reduce CO2 emissions in Croatia by 82%. → Use of energy storage could improve and guide development of a real energy system. → The paper shows results of an energy planning

  1. Optimization for operating modes based on simulation of seasonal underground thermal energy storage

    Institute of Scientific and Technical Information of China (English)

    Jun ZHAO; Yan CHEN; Xinguo LI

    2008-01-01

    A simulation was performed, which concerned the feasibility of seasonal underground thermal energy storage (UTES) in Tianjin, China. The investigated sys-tem consisted of 8 boreholes. In summer, residual solar thermal energy was emitted into the soil surrounding the borehole heat exchangers through which the stored energy was extracted in winter with a ground coupled heat pump (GCHP) to provide a proper heating temperature. A simulation study was performed to study the influence of system operation modes on thermal recovery based on the experimental data of a GCHP system, local met-eorological conditions and soil properties in Tianjin. The results indicate a thermal recovery ratio of less than 67% and different temperature distributions under three modes. Finally, an operation mode was suggested based on both lower loss and better thermal recovery in the UTES.

  2. 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

  3. 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.

  4. A Rule Based Energy Management System of Experimental Battery/Supercapacitor Hybrid Energy Storage System for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Qiao Zhang

    2016-01-01

    Full Text Available In this paper, a simple and efficient rule based energy management system for battery and supercapacitor hybrid energy storage system (HESS used in electric vehicles is presented. The objective of the proposed energy management system is to focus on exploiting the supercapacitor characteristics and on increasing the battery lifetime and system efficiency. The role of the energy management system is to yield battery reference current, which is subsequently used by the controller of the DC/DC converter. First, a current controller is designed to realize load current distribution between battery and supercapacitor. Then a voltage controller is designed to ensure the supercapacitor SOC to fluctuate within a preset reasonable variation range. Finally, a commercial experimental platform is developed to verify the proposed control strategy. In addition, the energy efficiency and the cost analysis of the hybrid system are carried out based on the experimental results to explore the most cost-effective tradeoff.

  5. ERDA's Chemical Energy Storage Program

    Science.gov (United States)

    Swisher, J. H.; Kelley, J. H.

    1977-01-01

    The Chemical Energy Storage Program is described with emphasis on hydrogen storage. Storage techniques considered include pressurized hydrogen gas storage, cryogenic liquid hydrogen storage, storage in hydride compounds, and aromatic-alicyclic hydrogen storage. Some uses of energy storage are suggested. Information on hydrogen production and hydrogen use is also presented. Applications of hydrogen energy systems include storage of hydrogen for utilities load leveling, industrial marketing of hydrogen both as a chemical and as a fuel, natural gas supplementation, vehicular applications, and direct substitution for natural gas.

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

    Directory of Open Access Journals (Sweden)

    Xia Long

    2016-05-01

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

  7. Aqueous manganese dioxide ink for paper-based capacitive energy storage devices.

    Science.gov (United States)

    Qian, Jiasheng; Jin, Huanyu; Chen, Bolei; Lin, Mei; Lu, Wei; Tang, Wing Man; Xiong, Wei; Chan, Lai Wa Helen; Lau, Shu Ping; Yuan, Jikang

    2015-06-01

    We report a simple approach based on a chemical reduction method to synthesize aqueous inorganic ink comprised of hexagonal MnO2 nanosheets. The MnO2 ink exhibits long-term stability and continuous thin films can be formed on various substrates without using any binder. To obtain a flexible electrode for capacitive energy storage, the MnO2 ink was printed onto commercially available A4 paper pretreated with multiwalled carbon nanotubes. The electrode exhibited a maximum specific capacitance of 1035 F g(-1) (91.7 mF cm(-2)). Paper-based symmetric and asymmetric capacitors were assembled, which gave a maximum specific energy density of 25.3 Wh kg(-1) and a power density of 81 kW kg(-1). The device could maintain a 98.9% capacitance retention over 10 000 cycles at 4 A g(-1). The MnO2 ink could be a versatile candidate for large-scale production of flexible and printable electronic devices for energy storage and conversion.

  8. Thermodynamic Analysis of a Diesel Engine Integrated with a PCM Based Energy Storage System

    Directory of Open Access Journals (Sweden)

    R. Velraj

    2010-03-01

    Full Text Available This work describes the energy and exergy analysis of a diesel engine integrated with a PCM based energy storage system, and provides more realistic and meaningful assessment than the conventional energy analysis. Using actual system data, the assessments of energy and exergy saved, and energy and exergy efficiencies are done. The exergy saved in the overall system is quantified and illustrated using an exergy flow diagram. Also, energy and exergy flow diagrams are compared. It is observed through the analysis that 6.13% of the total energy of the fuel is saved using the TES system. From the exergy analysis, it is identified that only 0.47% of the chemical availability of the fuel is saved. The energy efficiency of the integrated system is found to be varying between 3.19% and 34.15%. In contrast, the exergy efficiency, which incorporates the second law of thermodynamics for the integrated system, ranges from 0.25% to 27.41%.

  9. 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.

  10. Thermodynamic analysis of an integrated energy system based on compressed air energy storage (CAES) system and Kalina cycle

    International Nuclear Information System (INIS)

    Highlights: • An integrated energy system based on CAES and Kalina cycle is proposed. • The design and modeling of the CAES–KCS6 system are laid out. • The energy analysis and exergy analysis of the proposed system are carried out. • A parametric analysis is conducted to examine their effect on system performance. - Abstract: High penetration of renewable power sources into power system leads to significant challenge in balancing of power generation and consumption due to the highly erratic nature of renewable energies. Integrating the energy storage system (ESS) with power system can weaken these negative effects effectively. Compressed air energy storage (CAES) system as one of the grid-scale ESS technologies has grown rapidly in the past few years. However, the temperature of exhaust from low pressure turbine during discharge process is still high enough to utilize. An integrated energy system consisting of a CAES system and a Kalina cycle system 6 (KCS6) is proposed to recover this waste heat. The thermodynamic analyses including energy analysis and exergy analysis are evaluated by using steady-state mathematical model and thermodynamic laws. The second law efficiency of the proposed CAES–KCS6 system can be improved nearly 4% compared to that of the single conventional CAES system. Meanwhile, the parametric analysis is also carried out to evaluate the effects of some key parameters on system performance, such as the turbine inlet temperature (TIT), inlet pressure of low pressure turbine and the air storage cavern temperature. Results show that all of these parameters have positive effect on system exergy efficiency

  11. Chemical energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Schloegl, Robert (ed.) [Fritz-Haber-Institute of the Max Planck Society, Berlin (Germany). Dept. of Inorganic Chemistry

    2013-02-01

    The use of regenerative energy in many primary forms leads to the necessity to store grid dimensions for maintaining continuous supply and enabling the replacement of fossil fuel systems. Chemical energy storage is one of the possibilities besides mechano-thermal and biological systems. This work starts with the more general aspects of chemical energy storage in the context of the geosphere and evolves to dealing with aspects of electrochemistry, catalysis, synthesis of catalysts, functional analysis of catalytic processes and with the interface between electrochemistry and heterogeneous catalysis. Top-notch experts provide a sound, practical, hands-on insight into the present status of energy conversion aimed primarily at the young emerging research front.

  12. Development of a PMAD System for Flywheel Based Energy Storage System

    Science.gov (United States)

    Wolff, Fred

    2001-01-01

    We will discuss the following: (1) the Flywheel Energy Storage System (FESS) program objective; (2) benefits of flywheels for the International Space Station; (3) the FESS development team; (4) FESS electrical requirements; (5) FESS electrical architecture; and (6) electrical subsystem functionality. The objective of the FESS program is to demonstrate flywheel technologies operating together as a system and having improved performance characteristics over batteries in a low earth orbit energy storage application (such as the ISS).

  13. 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...... is defined by minimizing the utilization costs of the energy storage equipment. The weather conditions recorded in four different weeks between April and December are used as case studies to test the proposed EMS and the results obtained are compared with a conventional EMS based on the state...

  14. 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

    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 in...

  15. 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.

  16. 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.

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

    International Nuclear Information System (INIS)

    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

  18. 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.

  19. 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

  20. Thermal energy storage application areas

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-01

    The use of thermal energy storage in the areas of building heating and cooling, recovery of industrial process and waste heat, solar power generation, and off-peak energy storage and load management in electric utilities is reviewed. (TFD)

  1. 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

    of storage systems even less economically viable in market circumstances, despite economics of scale. The paper shows results of an energy planning methodology applied to several cases where use of smart energy storage system helps integration of energy flows, transformations and energy demand...... at the location of the energy end-use or close to it. Main results presented in this paper focus on planning a 100% independent energy system of Croatia. They also show the role of energy storage in a self-sustainable energy system with excess electricity production from renewable energy sources. The technical......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...

  2. 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.

  3. 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.

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

    International Nuclear Information System (INIS)

    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. Test report : Milspray Scorpion energy storage device.

    Energy Technology Data Exchange (ETDEWEB)

    Rose, David Martin; Schenkman, Benjamin L.; Borneo, Daniel R.

    2013-08-01

    The Department of Energy Office of Electricity (DOE/OE), Sandia National Laboratory (SNL) and the Base Camp Integration Lab (BCIL) partnered together to incorporate an energy storage system into a microgrid configured Forward Operating Base to reduce the fossil fuel consumption and to ultimately save lives. Energy storage vendors have supplied their systems to SNL Energy Storage Test Pad (ESTP) for functional testing and a subset of these systems were selected for performance evaluation at the BCIL. The technologies tested were electro-chemical energy storage systems comprised of lead acid, lithium-ion or zinc-bromide. MILSPRAY Military Technologies has developed an energy storage system that utilizes lead acid batteries to save fuel on a military microgrid. This report contains the testing results and some limited assessment of the Milspray Scorpion Energy Storage Device.

  6. Superconducting magnetic energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Hassenzahl, W.

    1988-08-01

    Recent programmatic developments in Superconducting Magnetic Energy Storage (SMES) have prompted renewed and widespread interest in this field. In mid 1987 the Defense Nuclear Agency, acting for the Strategic Defense Initiative Office, issued a request for proposals for the design and construction of SMES Engineering Test Model (ETM). Two teams, one led by Bechtel and the other by Ebasco, are now engaged in the first phase of the development of a 10 to 20 MWhr ETM. This report presents the rationale for energy storage on utility systems, describes the general technology of SMES, and explains the chronological development of the technology. The present ETM program is outlined; details of the two projects for ETM development are described in other papers in these proceedings. The impact of high T/sub c/ materials on SMES is discussed. 69 refs., 3 figs., 3 tabs.

  7. Superconductive magnetic energy storage

    International Nuclear Information System (INIS)

    Technical and economic aspects of large scale superconductive magnetic energy storage are discussed. This paper is a review of a program which has been under way at the University of Wisconsin since 1970. Early work between 1970 and 1976 was primarily involved in providing economic and technical feasibility of the concept. The present program deals with component development and detailed design ultimately leading to construction of a large superconducting magnet capable of storing 1000 to 10,000 MWh. The magnet is a single-layered segmented solenoid approx. 100 m radius. Energy containment is achieved economically by burying the magnet underground in bedrock tunnels. Magnetic loads are transmitted from the conductor to bedrock through glass fiber reinforced composite struts. The conductor consists of a composite of aluminium and NbTi and is designed for full cryogenic stability in 1.8 K superfluid helium. The dewar-conductor assembly will be rippled in a 1 m radius of curvature to reduce the hoop stress tension. A Graetz bridge is required to convert the d.c. superconducting current into a.c. current in the three-phase power system. Economic analysis indicates that superconductive magnetic energy storage is competitive with alternative large scale storage schemes for units greater than 1000 MWh size. (U.K.)

  8. 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.

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

    OpenAIRE

    Changbin Hu; Shanna Luo; Zhengxi Li; Xin Wang; Li Sun

    2015-01-01

    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 ...

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

    International Nuclear Information System (INIS)

    Highlights: • Energy management strategy for hybrid stand-alone power plant with hydrogen storage. • Optimal scheduling of storage devices to minimize the utilization costs. • A scenario tree method is used to manage uncertainties of weather and load forecasts. • A reduction of operational costs and energy losses is achieved. - Abstract: 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 is defined by minimizing the utilization costs of the energy storage equipment. The weather conditions recorded in four different weeks between April and December are used as case studies to test the proposed EMS and the results obtained are compared with a conventional EMS based on the state-of-charge of batteries. The results show a reduction of utilization costs of about 15% in comparison to conventional SOC-based EMS and an increase of the average energy storage efficiency

  11. 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

    2015-02-01

    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.

  12. 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

  13. 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. PMID:27531643

  14. Singular Perturbation Theory-Based Qualitative Dynamics Investigation of Flywheel Energy Storage System in Discharge Mode

    Directory of Open Access Journals (Sweden)

    Weiya Zhang

    2014-01-01

    Full Text Available An investigation on qualitative dynamics in a voltage-current dual-loop controlled flywheel energy storage system (FESS operating in discharge mode is presented in this paper, providing novel insights into the effect of two-timescale characteristics on the safety and stability of energy transmission of FESS. Based on singular perturbation theory, a two-timescale approach is proposed to separate the FESS into the fast and slow subsystems. Stability analysis of the transient fixed points confirms the effects of systemic parameters on FESS’s dynamics and indicates that the FESS shifts from the spiking state to the quiescent state when the slow variable crosses the bifurcation point of the fast subsystem. Mechanism analysis reveals that the root cause of the qualitative dynamics is the voltage instability of the FESS. Moreover, the feasibility boundaries of key parameters are derived, and application requirements of the proposed approach are also discussed, guiding the extension of the approach to engineering applications and solving the dynamics analysis problem to some extent at a theoretical analysis level. Constant voltage discharge experiment is performed based on the FESS test bench built in Key Laboratory of Smart Grid of Ministry of Education, Tianjin University, which validates the theoretical results.

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

    OpenAIRE

    Julio Pascual; Pablo Sanchis; Luis Marroyo

    2014-01-01

    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, ventilat...

  16. Short term thermal energy storage

    OpenAIRE

    Abhat, A.

    1980-01-01

    The present paper reviews the problem of short term thermal energy storage for low temperature solar heating applications. The techniques of sensible and latent heat storage are discussed, with particular emphasis on the latter. Requirements for hot water storage subsystems are provided and the importance of stratification in hot water storage tanks is described. Concerning latent heat storage, both material and heat exchanger aspects are considered in detail. The example of a passively opera...

  17. 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.

  18. Energy Storage System

    Science.gov (United States)

    1996-01-01

    SatCon Technology Corporation developed the drive train for use in the Chrysler Corporation's Patriot Mark II, which includes the Flywheel Energy Storage (FES) system. In Chrysler's experimental hybrid- electric car, the hybrid drive train uses an advanced turboalternator that generates electricity by burning a fuel; a powerful, compact electric motor; and a FES that eliminates the need for conventional batteries. The FES system incorporates technology SatCon developed in more than 30 projects with seven NASA centers, mostly for FES systems for spacecraft attitude control and momentum recovery. SatCon will continue to develop the technology with Westinghouse Electric Corporation.

  19. 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

  20. 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...... storage (ES) is used to improve the system dynamic response, reduce the distortion and provide damping for frequency oscillations caused by renewable resources. ES overload capacity is utilized for rapid initial control of frequency in MG. To achieve this goal, EMS based on fuzzy decision mechanism...... 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...

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

    Science.gov (United States)

    Shieh, Jen-Yu; Wu, Cheng-Hung; Tsai, Sung-Ying; Yu, Hsin Her

    2016-02-01

    In this paper, graphene and carbon nanotubes dispersed in a pectin solution are examined as a precursor for electrode fabrication for supercapacitor applications. The carbon nanotubes not only prevent the stacking of graphene sheets, but also act as spacers and binders. Dropping the hybrid conductive suspension onto sandpaper is found to form a sandpaper-based electrode that improves the specific capacitance of a subsequently fabricated supercapacitor because of its high surface area. In particular, the large contact surface of the sandpaper allows it to absorb more electrolyte ions and increases the number of ions assembled on the electrode surface. For the supercapacitor fabrication, replacing the liquid or solid electrolyte with a gel electrolyte prevents leakage and contact discontinuity. Therefore, a high-performance supercapacitor can be constructed with one separator coated with a gel electrolyte inserted between two fine-sandpaper-based electrodes, which can be assembled into a sandwich structure by hot pressing. 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.

  2. Dispatching of Wind/Battery Energy Storage Hybrid Systems Using Inner Point Method-Based Model Predictive Control

    Directory of Open Access Journals (Sweden)

    Deyou Yang

    2016-08-01

    Full Text Available The application of large scale energy storage makes wind farms more dispatchable, which lowers operating risks to the grid from interconnected large scale wind farms. In order to make full use of the flexibility and controllability of energy storage to improve the schedulability of wind farms, this paper presents a rolling and dispatching control strategy with a battery energy storage system (BESS based on model predictive control (MPC. The proposed control scheme firstly plans expected output, i.e., dispatching order, of a wind/battery energy storage hybrid system based on the predicted output of the wind farm, then calculates the order in the predictive horizon with the receding horizon optimization and the limitations of energy storage such as state of charge and depth of charge/discharge to maintain the combination of active output of the wind farm and the BESS to track dispatching order at the extreme. The paper shows and analyses the effectiveness of the proposed strategy with different sizes of capacity of the BESS based on the actual output of a certain actual wind farm in the northeast of China. The results show that the proposed strategy that controls the BESS could improve the schedulability of the wind farm and maintain smooth output of wind/battery energy storage hybrid system while tracking the dispatching orders. When the capacity of the BESS is 20% or the rated capacity of the wind farm, the mean dispatching error is only 0.153% of the rated capacity of the wind farm.

  3. MEMS-based storage devices : integration in energy-constrained mobile systems

    NARCIS (Netherlands)

    Khatib, Mohammed Ghiath

    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 t

  4. 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).

  5. 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...

  6. 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...

  7. NaOH-based high temperature heat-of-fusion thermal energy storage device

    Science.gov (United States)

    Cohen, B. M.; Rice, R. E.

    1978-01-01

    A material called Thermkeep, developed as a low-cost method for the storage of thermal energy for solar electric power generating systems is discussed. The storage device consists of an insulated cylinder containing Thermkeep in which coiled tubular heat exchangers are immersed. A one-tenth scale model of the design contains 25 heat-exchanger tubes and 1500 kg of Thermkeep. Its instrumentation includes thermocouples to measure internal Thermkeep temperatures, vessel surface, heated shroud surface, and pressure gauges to indicate heat-exchanger pressure drops. The test-circuit design is presented and experimental results are discussed.

  8. 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

    2016-09-01

    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.

  9. 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.

  10. Advanced materials for energy storage.

    Science.gov (United States)

    Liu, Chang; Li, Feng; Ma, Lai-Peng; Cheng, Hui-Ming

    2010-02-23

    Popularization of portable electronics and electric vehicles worldwide stimulates the development of energy storage devices, such as batteries and supercapacitors, toward higher power density and energy density, which significantly depends upon the advancement of new materials used in these devices. Moreover, energy storage materials play a key role in efficient, clean, and versatile use of energy, and are crucial for the exploitation of renewable energy. Therefore, energy storage materials cover a wide range of materials and have been receiving intensive attention from research and development to industrialization. In this Review, firstly a general introduction is given to several typical energy storage systems, including thermal, mechanical, electromagnetic, hydrogen, and electrochemical energy storage. Then the current status of high-performance hydrogen storage materials for on-board applications and electrochemical energy storage materials for lithium-ion batteries and supercapacitors is introduced in detail. The strategies for developing these advanced energy storage materials, including nanostructuring, nano-/microcombination, hybridization, pore-structure control, configuration design, surface modification, and composition optimization, are discussed. Finally, the future trends and prospects in the development of advanced energy storage materials are highlighted.

  11. 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

    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......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...... 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...

  12. 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.

  13. Battery energy storage market feasibility study

    International Nuclear Information System (INIS)

    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. 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.

  15. 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.

  16. 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.

  17. Superconducting energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Giese, R.F.

    1993-10-01

    This report describes the status of energy storage involving superconductors and assesses what impact the recently discovered ceramic superconductors may have on the design of these devices. Our description is intended for R&D managers in government, electric utilities, firms, and national laboratories who wish an overview of what has been done and what remains to be done. It is assumed that the reader is acquainted with superconductivity, but not an expert on the topics discussed here. Indeed, it is the author`s aim to enable the reader to better understand the experts who may ask for the reader`s attention, support, or funding. This report may also inform scientists and engineers who, though expert in related areas, wish to have an introduction to our topic.

  18. Thermal energy storage program description

    Energy Technology Data Exchange (ETDEWEB)

    Reimers, E. [Dept. of Energy, Washington, DC (United States)

    1989-03-01

    The U.S. Department of Energy (DOE) has sponsored applied research, development, and demonstration of technologies aimed at reducing energy consumption and encouraging replacement of premium fuels (notably oil) with renewable or abundant indigenous fuels. One of the technologies identified as being able to contribute to these goals is thermal energy storage (TES). Based on the potential for TES to contribute to the historic mission of the DOE and to address emerging energy issues related to the environment, a program to develop specific TES technologies for diurnal, industrial, and seasonal applications is underway. Currently, the program is directed toward three major application targets: (1) TES development for efficient off-peak building heating and cooling, (2) development of advanced TES building materials, and (3) TES development to reduce industrial energy consumption.

  19. 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.

  20. Development of Cellulose-Based, Nanostructured, Conductive Paper for Biomolecular Extraction and Energy Storage Applications

    OpenAIRE

    Razaq, Aamir

    2011-01-01

    Conductive paper materials consisting of conductive polymers and cellulose are promising for high-tech applications (energy storage and biosciences) due to outstanding aspects of environmental friendliness, mechanical flexibility, electrical conductivity and efficient electroactive behavior. Recently, a conductive composite paper material was developed by covering the individual nanofibers of cellulose from the green algae Cladophora with a polypyrrole (PPy) layer. The PPy-Cladophora cellulos...

  1. 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.

  2. 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

  3. 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.

  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

    This paper presents a centralized strategy for equalizing the state of charge of distributed energy storage systems in an islanded DC microgrid. The proposed strategy is based on a simple algorithm called equalization algorithm, which modifies the charge or discharge rate by weighting the virtual...... 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. 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)

  6. 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. PMID:26011895

  7. 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

    , produces a signal based on the output difference between the ESDC and saturated ES and augment the signal to the ESDC to alleviate the adverse effect of saturation. The AWC is designed with the reduced-order model of power system and linear matrix inequality. Detailed design procedure is introduced. Case......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......), and hence, reduce the required size of ES. The phenomenon that the capacity of ES is smaller than the required value produced by the ESDC, is modeled as actuator saturation using the saturation function. The proposed method is to design a anti-windup compensator (AWC), which in the event of saturation...

  8. Optimization of active magnetic bearings for automotive flywheel energy storage systems based on soft magnetic materials

    Directory of Open Access Journals (Sweden)

    Wegleiter H.

    2013-01-01

    Full Text Available For active magnetically suspended rotors in mobile flywheel energy storage systems the lowest possible weight, smallest size and a low price is required. Since the flywheel is operated in vacuum and very little heat can be dissipated from the rotor, the bearing’s magnetic losses have to be as minimal as well. This paper compares the design and optimization of homopolar radial active magnetic bearings with 3 different types of laminated steel. The first type is a standard transformer steel, the second one is high flux cobalt steel and the third one is high flux cobalt steel with high tensile strength.

  9. 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.

  10. Energy storage system for a pulsed DEMO

    International Nuclear Information System (INIS)

    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 MWhe 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

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. Interactive smart battery storage for a PV and wind hybrid energy management control based on conservative power theory

    Science.gov (United States)

    Godoy Simões, Marcelo; Davi Curi Busarello, Tiago; Saad Bubshait, Abdullah; Harirchi, Farnaz; Antenor Pomilio, José; Blaabjerg, Frede

    2016-04-01

    This paper presents interactive smart battery-based storage (BBS) for wind generator (WG) and photovoltaic (PV) systems. The BBS is composed of an asymmetric cascaded H-bridge multilevel inverter (ACMI) with staircase modulation. The structure is parallel to the WG and PV systems, allowing the ACMI to have a reduction in power losses compared to the usual solution for storage connected at the DC-link of the converter for WG or PV systems. Moreover, the BBS is embedded with a decision algorithm running real-time energy costs, plus a battery state-of-charge manager and power quality capabilities, making the described system in this paper very interactive, smart and multifunctional. The paper describes how BBS interacts with the WG and PV and how its performance is improved. Experimental results are presented showing the efficacy of this BBS for renewable energy applications.

  16. University of Arizona Compressed Air Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Joseph; Muralidharan, Krishna

    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. 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.

  18. 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

  19. 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.

  20. 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.

  1. Grid Inertial Response-Based Probabilistic Determination of Energy Storage System Capacity Under High Solar Penetration

    International Nuclear Information System (INIS)

    It is well-known that responsive battery energy storage systems (BESSs) are an effective means to improve the grid inertial response to various disturbances including the variability of the renewable generation. One of the major issues associated with its implementation is the difficulty in determining the required BESS capacity mainly due to the large amount of inherent uncertainties that cannot be accounted for deterministically. In this study, a probabilistic approach is proposed to properly size the BESS from the perspective of the system inertial response, as an application of probabilistic risk assessment (PRA). The proposed approach enables a risk-informed decision-making process regarding (1) the acceptable level of solar penetration in a given system and (2) the desired BESS capacity (and minimum cost) to achieve an acceptable grid inertial response with a certain confidence level

  2. 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...

  3. 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

  4. Integrating experimental and numerical methods for a scenario-based quantitative assessment of subsurface energy storage options

    Science.gov (United States)

    Kabuth, Alina; Dahmke, Andreas; Hagrey, Said Attia al; Berta, Márton; Dörr, Cordula; Koproch, Nicolas; Köber, Ralf; Köhn, Daniel; Nolde, Michael; Tilmann Pfeiffer, Wolf; Popp, Steffi; Schwanebeck, Malte; Bauer, Sebastian

    2016-04-01

    Within the framework of the transition to renewable energy sources ("Energiewende"), the German government defined the target of producing 60 % of the final energy consumption from renewable energy sources by the year 2050. However, renewable energies are subject to natural fluctuations. Energy storage can help to buffer the resulting time shifts between production and demand. Subsurface geological structures provide large potential capacities for energy stored in the form of heat or gas on daily to seasonal time scales. In order to explore this potential sustainably, the possible induced effects of energy storage operations have to be quantified for both specified normal operation and events of failure. The ANGUS+ project therefore integrates experimental laboratory studies with numerical approaches to assess subsurface energy storage scenarios and monitoring methods. Subsurface storage options for gas, i.e. hydrogen, synthetic methane and compressed air in salt caverns or porous structures, as well as subsurface heat storage are investigated with respect to site prerequisites, storage dimensions, induced effects, monitoring methods and integration into spatial planning schemes. The conceptual interdisciplinary approach of the ANGUS+ project towards the integration of subsurface energy storage into a sustainable subsurface planning scheme is presented here, and this approach is then demonstrated using the examples of two selected energy storage options: Firstly, the option of seasonal heat storage in a shallow aquifer is presented. Coupled thermal and hydraulic processes induced by periodic heat injection and extraction were simulated in the open-source numerical modelling package OpenGeoSys. Situations of specified normal operation as well as cases of failure in operational storage with leaking heat transfer fluid are considered. Bench-scale experiments provided parameterisations of temperature dependent changes in shallow groundwater hydrogeochemistry. As a

  5. 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 of

  6. Low energy ion storage devices

    International Nuclear Information System (INIS)

    While high energy physicists have found it expedient to store ions at increasingly higher energies in devices of greater size and complexity, atomic physicists have generally attempted to store ions at ever lower energies, and often in miniaturized containers. However, many of the techniques used at both high and low energies are analogous or related. Three basic means of ion containment have been used: the dc electrostatic trap, the Penning-type trap with uniform magnetic field and quadrupole dc potential, and the radio-frequency quadrupole trap in either the cylindrically symmetric or storage-ring configurations. Each trapping configuration has characteristic advantages or drawbacks for particular measurements. Each method is described

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

    International Nuclear Information System (INIS)

    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

  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. 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.

  10. REVIEW ON PHASE CHANGE MATERIALAS THERMAL ENERGY STORAGE

    OpenAIRE

    Bharti H. Verma; S V PRAYAGI; J. A. Gotmare

    2014-01-01

    Energy demands in the commercial, industrial, and utility sectors vary on daily, weekly, and seasonal bases. These demands can be matched with the help of thermal energy storage (TES) systems. This paper presentsTES using phase change material (PCMs) and their application. The use of latent heat storage system using phase change material (PCM) is an effective way of storing thermal energy and has advantages of high energy storage density and isothermal nature of the storage pro...

  11. High temperature superconducting magnetic energy storage for future NASA missions

    Science.gov (United States)

    Faymon, Karl A.; Rudnick, Stanley J.

    1988-01-01

    Several NASA sponsored studies based on 'conventional' liquid helium temperature level superconductivity technology have concluded that superconducting magnetic energy storage has considerable potential for space applications. The advent of high temperature superconductivity (HTSC) may provide additional benefits over conventional superconductivity technology, making magnetic energy storage even more attractive. The proposed NASA space station is a possible candidate for the application of HTSC energy storage. Alternative energy storage technologies for this and other low Earth orbit missions are compared.

  12. 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.

  13. Seasonal sensible thermal energy storage solutions

    OpenAIRE

    Lavinia Gabriela SOCACIU

    2012-01-01

    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...

  14. Heat transfer and parametric studies of an encapsulated phase change material based cool thermal energy storage system

    Institute of Scientific and Technical Information of China (English)

    CHERALATHAN M.; VELRAJ R.; RENGANARAYANAN S.

    2006-01-01

    This work investigates the transient behaviour of a phase change material based cool thermal energy storage (CTES)system comprised of a cylindrical storage tank filled with encapsulated phase change materials (PCMs) in spherical container integrated with an ethylene glycol chiller plant. A simulation program was developed to evaluate the temperature histories of the heat transfer fluid (HTF) and the phase change material at any axial location during the charging period. The results of the model were validated by comparison with experimental results of temperature profiles of HTF and PCM. The model was also used to investigate the effect of porosity, Stanton number, Stefan number and Peclet number on CTES system performance. The results showed that increase in porosity contributes to a higher rate of energy storage. However, for a given geometry and heat transfer coefficient, the mass of PCM charged in the unit decreases as the increase in porosity. The St number as well as the Ste number is also influential in the performance of the unit. The model is a convenient and more suitable method to determine the heat transfer characteristics of CTES system. The results reported are much useful for designing CTES system.

  15. 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

  16. Multiagent Based Distributed Control for State-of-Charge Balance of Distributed Energy Storage in DC microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Dragicevic, Tomislav; Garcia Plaza, Manuel;

    2014-01-01

    In this paper, a distributed multiagent based algorithm is proposed to achieve SoC balance for DES in the DC microgrid by means of voltage scheduling. Reference voltage given is adjusted instead of droop gain. Dynamic average consensus algorithm is explored in each agent to get the required...... information for scheduling voltage autonomously. State-space analysis on a single energy storage unit and simulation verification shows that the proposed method has two advantages. Firstly, modifying the reference voltage given has less impact on system stability compared to gain scheduling. Secondly, by...

  17. Development of Rotordynamics Program Based on the 2D Finite Element Method for Flywheel Energy Storage System

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Dong Sik; Kim, Jae Gu; Kim, Hyo Jung; Choi, Byeong Keun [Gyeongsang National University, Jinju (Korea, Republic of); Bae, Yong Cae; Lee, Wook Ryun [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2010-11-15

    Flywheel energy storage system (FESS) is defined as a high speed rotating flywheel system that can save surplus electric power. The FESS is proposed as an efficient energy storage system because it can accumulate a large amount of energy when it is operated at a high rotating speed and no mechanical problems are encountered. The FESS consists of a shaft, flywheel, motor/generator, bearings, and case. It is difficult to simulate rotor dynamics using common structure simulation programs because these programs are based on the 3D model and complex input rotating conditions. Therefore, in this paper, a program for the FESS based on the 2D FEM was developed. The 2D FEM can model easier than 3D, and it can present the multi-layer rotor with different material each other. Stiffness changing of the shaft caused by shrink fitting of the hub can be inputted to get clear solving results. The results obtained using the program were compared with those obtained using the common programs to determine any errors.

  18. 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.

  19. Combined solar collector and energy storage system

    Science.gov (United States)

    Jensen, R. N. (Inventor)

    1980-01-01

    A combined solar energy collector, fluid chiller and energy storage system is disclosed. A movable interior insulated panel in a storage tank is positionable flush against the storage tank wall to insulate the tank for energy storage. The movable interior insulated panel is alternately positionable to form a solar collector or fluid chiller through which the fluid flows by natural circulation.

  20. Application of Energy Storage in Power Systems

    Science.gov (United States)

    Alqunun, Khalid M.

    The purpose of this research is to determine the advantages of using energy storage systems. This study presents a model for energy storage in electric power systems. The model involves methods of reducing the operation cost of a power network and the calculation of capital cost of energy storage systems. Two test systems have been considered, the IEEE six-bus system and the IEEE 118-bus system, to analyze the impact of energy storage on power system economic operation. Properties of energy storage have been considered such as rated power investment cost and rated energy investment cost. Mixed integer programming has been used to formulate the model. A comparison between centralized energy storage system and distributed energy storage system have been proposed. The results show that distributed energy storage system has more impact on reducing total operation cost. Also, an analysis on optimal sizing of energy storage system with fixed investment cost is provided.

  1. Electrical Energy Storage for Renewable Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Helms, C. R.; Cho, K. J.; Ferraris, John; Balkus, Ken; Chabal, Yves; Gnade, Bruce; Rotea, Mario; Vasselli, John

    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. Significant accomplishments are detailed in each section. Those particularly noteworthy include: • Transition metal silicate cathodes with 2x higher storage capacity than commercial cobalt oxide cathodes were demonstrated. • MnO₂ nanowires, which are a promising replacement for RuO₂, were synthesized • PAN-based carbon nanofibers were prepared and characterized with an energy density 30-times higher than current ultracapacitors on the market and comparable to lead-acid batteries • An optimization-based control strategy for real-time power management of battery storage in wind farms was developed and demonstrated. • PVDF films were developed with breakdown strengths of > 600MVm⁻¹, a maximum energy density of approximately 15 Jcm⁻³, and an average dielectric constant of 9.8 (±1.2). Capacitors made from these films can support a 10-year lifetime operating at an electric field of 200 MV m⁻¹. 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.

  2. 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.

  3. 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.

  4. 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)

  5. 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 t

  6. Optimization of a carbon-based hybrid energy storage device with cerium (III) sulfate as redox electrolyte

    Science.gov (United States)

    Díaz, Patricia; González, Zoraida; Santamaría, Ricardo; Granda, Marcos; Menéndez, Rosa; Blanco, Clara

    2016-03-01

    The electrochemical performance of a carbon-based hybrid energy storage system, with Ce2(SO4)3/H2SO4 as inorganic redox electrolyte, was enhanced by optimizing several parameters of the device. A mass balance of the two electrodes forming the system together with the selection of a suitable activated carbon as negative electrode allowed the cell voltage to be increased up to 1.9 V. In addition, the use of a cation-exchange membrane significantly enhanced the electrochemical performance of the system by minimizing secondary reactions of cerium ions on the negative electrode. The optimized device reached energy and power density values up to ∼20 W h kg-1 and 524 W kg-1 respectively. Moreover, the system showed a good long-term electrochemical performance over 20,000 cycles.

  7. A thermal energy storage process for large scale electric applications

    OpenAIRE

    Desrues, T; Ruer, J; Marty, P.; Fourmigué, JF

    2009-01-01

    Abstract A new type of thermal energy storage process for large scale electric applications is presented, based on a high temperature heat pump cycle which transforms electrical energy into thermal energy and stores it inside two large regenerators, followed by a thermal engine cycle which transforms the stored thermal energy back into electrical energy. The storage principle is described, and its thermodynamic cycle is analyzed, leading to the theoretical efficiency of the storage...

  8. Nanoconfined hydrides for energy storage

    Science.gov (United States)

    Nielsen, Thomas K.; Besenbacher, Flemming; Jensen, Torben R.

    2011-05-01

    The world in the 21st century is facing increasing challenges within the development of more environmentally friendly energy systems, sustainable and `green chemistry' solutions for a variety of chemical and catalytic processes. Nanomaterials science is expected to contribute strongly by the development of new nanotools, e.g. for improving the performance of chemical reactions. Nanoconfinement is of increasing interest and may lead to significantly enhanced kinetics, higher degree of stability and/or more favourable thermodynamic properties. Nanoconfined chemical reactions may have a wide range of important applications in the near future, e.g. within the merging area of chemical storage of renewable energy. This review provides selected examples within nanoconfinement of hydrogen storage materials, which may serve as an inspiration for other research fields as well. Selected nanoporous materials, methods for preparation of nanoconfined systems and their hydrogen storage properties are reviewed.The world in the 21st century is facing increasing challenges within the development of more environmentally friendly energy systems, sustainable and `green chemistry' solutions for a variety of chemical and catalytic processes. Nanomaterials science is expected to contribute strongly by the development of new nanotools, e.g. for improving the performance of chemical reactions. Nanoconfinement is of increasing interest and may lead to significantly enhanced kinetics, higher degree of stability and/or more favourable thermodynamic properties. Nanoconfined chemical reactions may have a wide range of important applications in the near future, e.g. within the merging area of chemical storage of renewable energy. This review provides selected examples within nanoconfinement of hydrogen storage materials, which may serve as an inspiration for other research fields as well. Selected nanoporous materials, methods for preparation of nanoconfined systems and their hydrogen storage

  9. 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...

  10. Energy Conversion and Storage Program

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, E.J.

    1992-03-01

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

  11. 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.

  12. Improving Aquifer Thermal Energy Storage Efficiency

    OpenAIRE

    S. Kranz; G. Blöcher; Ali Saadat

    2015-01-01

    Aquifer thermal energy storage systems play an important role for the future energy supply systems. Such systems can decouple energy availability (e.g. fluctuating renewable energy, waste heat) and energy supply in times of demand. In order to fully contribute to the sustainability of energy supply, the essential requirements of energy storages are high energy efficiency, high reliability, cost effectiveness, as well as operational flexibility. Aquifer Thermal Energy Storage Systems (ATES) me...

  13. A Review of Energy Storage Technologies:For the integration of fluctuating renewable energy

    OpenAIRE

    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), Battery Energy Storage (BES), Flow Battery Energy Storage (FBES), Flywheel Energy Storage (FES), Supercapacitor Energy Storage (SCES), Superconducting Magnetic Energy Storage (SMES), Hydrogen Energy ...

  14. 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.

  15. Energy aspects of food storage

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R. (Bari Univ. (Italy). Ist. di Fisica Tecnica)

    1989-08-01

    In all industrial countries, the refrigeration industry is steadily occupying a place of greater importance because of the value of machines and equipment produced, as well as the products being treated and the energy used. Refrigeration is one of the many food storage techniques. Contrary to what we may think, this technique is the most expensive from the energy point of view, if all energy costs involved are taken into consideration. In industrial refrigeration plants, the measures for energy saving can be very effective, above all, if - at the design level - not only the initial costs have been correctly allocated, but also the operational costs.

  16. Hierarchically-Porous Carbon Derived from a Large-Scale Iron-based Organometallic Complex for Versatile Energy Storage.

    Science.gov (United States)

    Fan, Chao-Ying; Li, Huan-Huan; Wang, Hai-Feng; Sun, Hai-Zhu; Wu, Xing-Long; Zhang, Jing-Ping

    2016-06-22

    Inspired by the preparation of the hierarchically-porous carbon (HPC) derived from metal organic frameworks (MOFs) for energy storage, in this work, a simple iron-based metal- organic complex (MOC), which was simpler and cheaper compared with the MOF, was selected to achieve versatile energy storage. The intertwined 1 D nanospindles and enriched-oxygen doping of the HPC was obtained after one-step carbonization of the MOC. When employed in lithium-ion batteries, the HPC exhibited reversible capacity of 778 mA h g(-1) after 60 cycles at 50 mA g(-1) . Moreover, the HPC maintained a capacity of 188 mA h g(-1) after 400 cycles at 100 mA g(-1) as the anode material in a sodium-ion battery. In addition, the HPC served as the cathode matrix for evaluation of a lithium-sulfur battery. The general preparation process of the HPC is commercial, which is responsible for the large-scale production for its practical application.

  17. Hierarchically-Porous Carbon Derived from a Large-Scale Iron-based Organometallic Complex for Versatile Energy Storage.

    Science.gov (United States)

    Fan, Chao-Ying; Li, Huan-Huan; Wang, Hai-Feng; Sun, Hai-Zhu; Wu, Xing-Long; Zhang, Jing-Ping

    2016-06-22

    Inspired by the preparation of the hierarchically-porous carbon (HPC) derived from metal organic frameworks (MOFs) for energy storage, in this work, a simple iron-based metal- organic complex (MOC), which was simpler and cheaper compared with the MOF, was selected to achieve versatile energy storage. The intertwined 1 D nanospindles and enriched-oxygen doping of the HPC was obtained after one-step carbonization of the MOC. When employed in lithium-ion batteries, the HPC exhibited reversible capacity of 778 mA h g(-1) after 60 cycles at 50 mA g(-1) . Moreover, the HPC maintained a capacity of 188 mA h g(-1) after 400 cycles at 100 mA g(-1) as the anode material in a sodium-ion battery. In addition, the HPC served as the cathode matrix for evaluation of a lithium-sulfur battery. The general preparation process of the HPC is commercial, which is responsible for the large-scale production for its practical application. PMID:27219476

  18. Energy Storage Flywheels on Spacecraft

    Science.gov (United States)

    Bartlett, Robert O.; Brown, Gary; Levinthal, Joel; Brodeur, Stephen (Technical Monitor)

    2002-01-01

    With advances in carbon composite material, magnetic bearings, microprocessors, and high-speed power switching devices, work has begun on a space qualifiable Energy Momentum Wheel (EMW). An EMW is a device that can be used on a satellite to store energy, like a chemical battery, and manage angular momentum, like a reaction wheel. These combined functions are achieved by the simultaneous and balanced operation of two or more energy storage flywheels. An energy storage flywheel typically consists of a carbon composite rotor driven by a brushless DC motor/generator. Each rotor has a relatively large angular moment of inertia and is suspended on magnetic bearings to minimize energy loss. The use of flywheel batteries on spacecraft will increase system efficiencies (mass and power), while reducing design-production time and life-cycle cost. This paper will present a discussion of flywheel battery design considerations and a simulation of spacecraft system performance utilizing four flywheel batteries to combine energy storage and momentum management for a typical LEO satellite. A proposed set of control laws and an engineering animation will also be presented. Once flight qualified and demonstrated, space flywheel batteries may alter the architecture of most medium and high-powered spacecraft.

  19. Phase Change Materials for Thermal Energy Storage

    OpenAIRE

    Stiebra, L; Cabulis, U; Knite, M

    2014-01-01

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

  20. A Distributed Energy System Based on Wind Energy Storage%一种基于风能储能的分布式能源系统

    Institute of Scientific and Technical Information of China (English)

    王凯; 张远; 孙燕平; 杨科

    2013-01-01

    In order to verify and study the output characteristics of distributed energy system based on the integration system of wind power generation and Advanced Adiabatic Compressed Air Energy Storage (AA-CAES),a distributed energy system with wind energy storage technology was established and parametric expressions about energy were deduced thermodynamically. The relationship between the output characteristics of distributed energy system and heat energy utilization was determined , and advantages of distributed energy system were analyzed with an example of one office building .Results show that power is decreasing with heating increasing , meanwhile cooling and the total energy output are increasing; compared with the model of power , the total energy output of distributed energy model are more on the premise of ensuring the demand of cooling and heat ,and distributed energy model is more energy-efficient when the total energy output are the same .%为了验证和分析风电与先进绝热压缩空气储能( Advanced Adiabatic Compressed Air Energy Storage ,简称AA-CAES)集成系统用于分布式供能的能量输出特性,建立了以风能储能技术为基础的分布式能源系统模型,从热力学角度推导了与能量输出相关的参数表达式,得到了分布式能源系统冷热电输出特性与储热器中热量利用的关联性,并以某写字楼为例,分析了分布式能源系统的优势。结果表明:随系统供热量的增加,系统供电量减少,制冷量增加,且能量输出总量增加;在满足冷量和热量需求的前提下,相比供电模型,分布式供能模型有更多的供电量,而在能量输出相同的条件下,分布式能源系统模型更节能。

  1. Probe-based data storage

    CERN Document Server

    Koelmans, Wabe W; Abelmann, L

    2015-01-01

    Probe-based data storage attracted many researchers from academia and industry, resulting in unprecendeted high data-density demonstrations. This topical review gives a comprehensive overview of the main contributions that led to the major accomplishments in probe-based data storage. The most investigated technologies are reviewed: topographic, phase-change, magnetic, ferroelectric and atomic and molecular storage. Also, the positioning of probes and recording media, the cantilever arrays and parallel readout of the arrays of cantilevers are discussed. This overview serves two purposes. First, it provides an overview for new researchers entering the field of probe storage, as probe storage seems to be the only way to achieve data storage at atomic densities. Secondly, there is an enormous wealth of invaluable findings that can also be applied to many other fields of nanoscale research such as probe-based nanolithography, 3D nanopatterning, solid-state memory technologies and ultrafast probe microscopy.

  2. 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

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

    OpenAIRE

    Thai-Thanh Nguyen; Hyeong-Jun Yoo; Hak-Man Kim

    2015-01-01

    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 ...

  4. 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

    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......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...... 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....

  5. Test report : Raytheon / KTech RK30 energy storage system.

    Energy Technology Data Exchange (ETDEWEB)

    Rose, David Martin; Schenkman, Benjamin L.; Borneo, Daniel R.

    2013-10-01

    The Department of Energy Office of Electricity (DOE/OE), Sandia National Laboratories (SNL) and the Base Camp Integration Lab (BCIL) partnered together to incorporate an energy storage system into a microgrid configured Forward Operating Base to reduce the fossil fuel consumption and to ultimately save lives. Energy storage vendors will be sending their systems to SNL Energy Storage Test Pad (ESTP) for functional testing and then to the BCIL for performance evaluation. The technologies that will be tested are electro-chemical energy storage systems comprising of lead acid, lithium-ion or zinc-bromide. Raytheon/KTech has developed an energy storage system that utilizes zinc-bromide flow batteries to save fuel on a military microgrid. This report contains the testing results and some limited analysis of performance of the Raytheon/KTech Zinc-Bromide Energy Storage System.

  6. 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).

  7. A novel thermochemical energy storage and transportation concept based on concentrated solar irradiation-aided CaO-looping

    Science.gov (United States)

    Obermeier, Jonas; Müller, Karsten; Karagiannakis, George; Stubos, Athanasios; Arlt, Wolfgang

    2016-05-01

    To overcome the temporal and regional gap of surplus solar energy, the concept of thermochemical heat storage is discussed. In this particular case, the application of CaO and CaCO3 as energy carrying compounds for a trans-regional energy distribution concept is analyzed regarding the effective energetic and exergetic storage density. In a comprehensive sensitivity analysis, the influences of reaction temperature, conversion and heat recovery strategies are worked out. It can be seen that the effective storage density is strongly influenced by the preheating of reactants from ambient to reaction temperature. Thus, high conversion rates during forward and reverse reaction as well as improved heat recovery ratios are necessary to achieve a high energetic storage density. In case of effective exergetic storage density, carbonation temperature reaches an optimum. The method presented in this contribution can be applied to similar thermochemical heat storage systems and the results are of great importance for the process design and development of the suggested concept.

  8. Microwavable thermal energy storage material

    Energy Technology Data Exchange (ETDEWEB)

    Salyer, I.O.

    1998-09-08

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

  9. Microwavable thermal energy storage material

    Energy Technology Data Exchange (ETDEWEB)

    Salyer, Ival O. (Dayton, OH)

    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.

  10. Nuclear Hybrid energy Systems: Molten Salt Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Green, M.; Sabharwall, P.; Yoon, S. J.; Bragg-Sitton, S. B.; Stoot, C.

    2014-07-01

    Without growing concerns in reliable energy supply, the next generation in reliable power generation via hybrid energy systems is being developed. A hybrid energy system incorporates multiple energy input source sand multiple energy outputs. The vitality and efficiency of these combined systems resides in the energy storage application. Energy storage is necessary for grid stabilization because stored excess energy is used later to meet peak energy demands. With high thermal energy production the primary nuclear heat generation source, molten salt energy storage is an intriguing option because of its distinct thermal properties. This paper discusses the criteria for efficient energy storage and molten salt energy storage system options for hybrid systems. (Author)

  11. Wind farm battery energy storage technology based on power dispatching%基于电网调度的风电场蓄电池储能技术

    Institute of Scientific and Technical Information of China (English)

    孔飞飞; 晁勤; 袁铁江

    2012-01-01

    阐述了风电场蓄电池储能技术的原理和特点,分别介绍了国内外基于几种不同控制目标的风电场储能技术;分析了风电场储能容量估算的研究现状;提出了基于电网调度的风电场蓄电池储能技术是最可行的方案,并简要分析了应用基于电网调度的风电场蓄电池储能的技术课题.%The technical principle and application status of wind farm energy storage system were presented,several wind farm energy storage technologies based on different control goals at home and abroad were introduced respectively,the research status of wind farm energy storage capacity calculation were analyzed,the most feasible scheme,namely wind farm battery energy storage technology based on power dispatching was proposed,and some technical issues of applying wind farm battery energy storage technology based on power dispatching were simply analyzed.

  12. 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 combinatio...

  13. An Inexpensive Aqueous Flow Battery for Large-Scale Electrical Energy Storage Based on Water-Soluble Organic Redox Couples

    Energy Technology Data Exchange (ETDEWEB)

    Yang, B; Hoober-Burkhardt, L; Wang, F; Prakash, GKS; Narayanan, SR

    2014-05-21

    We introduce a novel Organic Redox Flow Battery (ORBAT), for Meeting the demanding requirements of cost, eco-friendliness, and durability for large-scale energy storage. ORBAT employs two different water-soluble organic redox couples on the positive and negative side of a flow battery. Redox couples such as quinones are particularly attractive for this application. No precious metal catalyst is needed because of the fast proton-coupled electron transfer processes. Furthermore, in acid media, the quinones exhibit good chemical stability. These properties render quinone-based redox couples very attractive for high-efficiency metal-free rechargeable batteries. We demonstrate the rechargeability of ORBAT with anthraquinone-2-sulfonic acid or anthraquinone-2,6-disulfonic acid on the negative side, and 1,2-dihydrobenzoquinone- 3,5-disulfonic acid on the positive side. The ORBAT cell uses a membrane-electrode assembly configuration similar to that used in polymer electrolyte fuel cells. Such a battery can be charged and discharged multiple times at high faradaic efficiency without any noticeable degradation of performance. We show that solubility and mass transport properties of the reactants and products are paramount to achieving high current densities and high efficiency. The ORBAT configuration presents a unique opportunity for developing an inexpensive and sustainable metal-free rechargeable battery for large-scale electrical energy storage. (C) The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.orgilicenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.

  14. Energy storage materials synthesized from ionic liquids.

    Science.gov (United States)

    Gebresilassie Eshetu, Gebrekidan; Armand, Michel; Scrosati, Bruno; Passerini, Stefano

    2014-12-01

    The advent of ionic liquids (ILs) as eco-friendly and promising reaction media has opened new frontiers in the field of electrochemical energy storage. Beyond their use as electrolyte components in batteries and supercapacitors, ILs have unique properties that make them suitable as functional advanced materials, media for materials production, and components for preparing highly engineered functional products. Aiming at offering an in-depth review on the newly emerging IL-based green synthesis processes of energy storage materials, this Review provides an overview of the role of ILs in the synthesis of materials for batteries, supercapacitors, and green electrode processing. It is expected that this Review will assess the status quo of the research field and thereby stimulate new thoughts and ideas on the emerging challenges and opportunities of IL-based syntheses of energy materials.

  15. Charging Graphene for Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jun

    2014-10-06

    Since 2004, graphene, including single atomic layer graphite sheet, and chemically derived graphene sheets, has captured the imagination of researchers for energy storage because of the extremely high surface area (2630 m2/g) compared to traditional activated carbon (typically below 1500 m2/g), excellent electrical conductivity, high mechanical strength, and potential for low cost manufacturing. These properties are very desirable for achieving high activity, high capacity and energy density, and fast charge and discharge. Chemically derived graphene sheets are prepared by oxidation and reduction of graphite1 and are more suitable for energy storage because they can be made in large quantities. They still contain multiply stacked graphene sheets, structural defects such as vacancies, and oxygen containing functional groups. In the literature they are also called reduced graphene oxide, or functionalized graphene sheets, but in this article they are all referred to as graphene for easy of discussion. Two important applications, batteries and electrochemical capacitors, have been widely investigated. In a battery material, the redox reaction occurs at a constant potential (voltage) and the energy is stored in the bulk. Therefore, the energy density is high (more than 100 Wh/kg), but it is difficult to rapidly charge or discharge (low power, less than 1 kW/kg)2. In an electrochemical capacitor (also called supercapacitors or ultracapacitor in the literature), the energy is stored as absorbed ionic species at the interface between the high surface area carbon and the electrolyte, and the potential is a continuous function of the state-of-charge. The charge and discharge can happen rapidly (high power, up to 10 kW/kg) but the energy density is low, less than 10 Wh/kg2. A device that can have both high energy and high power would be ideal.

  16. 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....

  17. 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.

  18. 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-...

  19. 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....

  20. 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...

  1. 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.

  2. A Novel Integrated Magnetic Structure Based DC/DC Converter for Hybrid Battery/Ultracapacitor Energy Storage Systems

    Energy Technology Data Exchange (ETDEWEB)

    Onar, Omer C [ORNL

    2012-01-01

    This manuscript focuses on a novel actively controlled hybrid magnetic battery/ultracapacitor based energy storage system (ESS) for vehicular propulsion systems. A stand-alone battery system might not be sufficient to satisfy peak power demand and transient load variations in hybrid and plug-in hybrid electric vehicles (HEV, PHEV). Active battery/ultracapacitor hybrid ESS provides a better solution in terms of efficient power management and control flexibility. Moreover, the voltage of the battery pack can be selected to be different than that of the ultracapacitor, which will result in flexibility of design as well as cost and size reduction of the battery pack. In addition, the ultracapacitor bank can supply or recapture a large burst of power and it can be used with high C-rates. Hence, the battery is not subjected to supply peak and sharp power variations, and the stress on the battery will be reduced and the battery lifetime would be increased. Utilizing ultracapacitor results in effective capturing of the braking energy, especially in sudden braking conditions.

  3. 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.

  4. Flywheel based energy storage systems and their engineering applications%飞轮储能系统及其工程应用

    Institute of Scientific and Technical Information of China (English)

    李翀; 王诗阳; 赵金龙

    2013-01-01

      飞轮储能系统是一种具有广阔应用前景的机械储能装置。本文介绍了飞轮储能系统的原理和基本结构,并阐述了飞轮储能系统在相应工程领域的应用情况。%Flywheel is a mechanical based energy storage method with a wide range of potential applications. In this paper, we introduce the principle and components of a flywheel energy storage system, and look at applications of the technology in relevant engineering fields.

  5. Analysis and design of systems for thermal-energy storage at moderate temperatures based on Phase Change Materials (PCM)

    OpenAIRE

    Trogrlic, Martina

    2014-01-01

    Because human population is growing at such a high rate, as well as the energy consumption per person, new ways of preserving and efficiently using available energy must be explored. Until new and abundant energy sources are found and means of their exploitation developed, research attention should be focused on finding ways of proper and safe use of what is nowadays available.In that sense, storage of thermal energy plays an important role both in heating and/or cooling applications, such as...

  6. Novel approach for decentralized energy supply and energy storage of tall buildings in Latin America based on renewable energy sources: Case study – Informal vertical community Torre David, Caracas – Venezuela

    International Nuclear Information System (INIS)

    This paper analyzes the concept of a decentralized power system based on wind energy and a pumped hydro storage system in a tall building. The system reacts to the current paradigm of power outage in Latin American countries caused by infrastructure limitations and climate change, while it fosters the penetration of renewable energy sources (RES) for a more diversified and secure electricity supply. An explicit methodology describes the assessment of technical, operational and economic potentials in a specific urban setting in Caracas/Venezuela. The suitability, applicability and the impacts generated by such power system are furthermore discussed at economic, social and technical level. - Highlights: ► We have modeled an innovative pico pumped hydro-storage system and wind power system for tall buildings. ► We conducted technical, economic and social analysis on these energy supply and storage alternatives. ► The energy storage system can achieve efficiencies within 30% and 35%. ► The energy storage is realistic and economic sensible in comparison to other solutions. ► The impacts of such a system in the current living conditions and safety issues of the building are minimum

  7. 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...

  8. 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.

  9. 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)

  10. Energy storage: a review of recent literature

    International Nuclear Information System (INIS)

    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

  11. The chemistry of energy conversion and storage.

    Science.gov (United States)

    Su, Dang Sheng

    2014-05-01

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

  12. Redox-oxide-based porous ceramics for efficient solar thermal energy conversion and storage

    OpenAIRE

    Agrafiotis, Christos; Becker, Andreas; Roeb, Martin; Sattler, Christian

    2015-01-01

    Air-operated Concentrated Solar Power Tower plants store the solar energy provided during on-sun operation as sensible heat in porous solid materials that operate as recuperators during off-sun operation. This concept can be rendered to a “hybrid” sensible/thermochemical one via coating the porous heat exchange modules with oxides of multivalent metals for which their reduction/oxidation reactions are accompanied by significant heat effects (e.g. Co3O4/CoO, BaO2/BaO, Mn2O3/Mn3O4, CuO/Cu2O) or...

  13. 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%.

  14. 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...... than PHES depending on the availability of suitable sites. FBES could also be utilised in the future for the integration of wind, but it may not have the scale required to exist along with electric vehicles. The remaining technologies will most likely be used for their current applications...

  15. 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).

  16. 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)

  17. Optimal Scheduling for the Complementary Energy Storage System Operation Based on Smart Metering Data in the DC Distribution System

    Directory of Open Access Journals (Sweden)

    Bokyung Ko

    2013-12-01

    Full Text Available The increasing penetration of distributed generation (DG sources in low-voltage grid feeders causes problems concerning voltage regulation. The penetration of DG sources such as photovoltaics (PVs in the distribution system can significantly impact the power flow and voltage conditions on the customer side. As the DG sources are more commonly connected to low-voltage distribution systems, voltage fluctuations in the distribution system are experienced because of the DG fluctuation and uncertainty. Therefore, the penetration of DGs in distribution systems is often limited by the required operating voltage ranges. By using an energy storage system (ESS, voltage fluctuation can be compensated for, thus satisfying the voltage regulation requirements. This paper presents an ESS scheduling algorithm based on the power injection data obtained from a smart metering system. The proposed ESS scheduling algorithm is designed for use within a direct current (DC distribution grid, which comprises customers, each with a PV and an ESS system. The purpose of this ESS scheduling algorithm is to optimize the ESS scheduling by considering the complementary operation among all the ESSs.

  18. 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.

  19. 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

  20. Nuclear Hybrid Energy Systems: Molten Salt Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    P. Sabharwall; M. Green; S.J. Yoon; S.M. Bragg-Sitton; C. Stoots

    2014-07-01

    With growing concerns in the production of reliable energy sources, the next generation in reliable power generation, hybrid energy systems, are being developed to stabilize these growing energy needs. The hybrid energy system incorporates multiple inputs and multiple outputs. The vitality and efficiency of these systems resides in the energy storage application. Energy storage is necessary for grid stabilizing and storing the overproduction of energy to meet peak demands of energy at the time of need. With high thermal energy production of the primary nuclear heat generation source, molten salt energy storage is an intriguing option because of its distinct properties. This paper will discuss the different energy storage options with the criteria for efficient energy storage set forth, and will primarily focus on different molten salt energy storage system options through a thermodynamic analysis

  1. 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.

  2. Energy storage in Canada - Embassy report

    International Nuclear Information System (INIS)

    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

  3. Battery energy storage market feasibility study - Expanded report

    International Nuclear Information System (INIS)

    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)

  4. MRI device – alternative for electrical energy storage

    Directory of Open Access Journals (Sweden)

    Molokáč, Š.

    2008-01-01

    Full Text Available It is well known, that the electrical energy storage in the large scale is basically difficult process. Such a process is marked by the energy losses, as the conversion of electrical energy into another form, is most frequently for example mechanical, and then back to the primary electrical form. Though, the superconducting magnetic energy storage (SMES technology offers the energy storage in an unchanged form, which is advantageous primarily in the achieved efficiency. Magnetic resonance imaging (MRI devices, commonly used in the medical facilities are based on the application of superconducting magnet. After its rejection from operation, there is possibility of using such devices for energy storage purposes. Additionally, such a technology of storage is also ecological.

  5. Efficiency of Compressed Air Energy Storage

    OpenAIRE

    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...

  6. 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.

  7. 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

  8. ENERGY STAR Certified Data Center Storage

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Data Center Storage that are effective as of...

  9. 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...

  10. 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.

  11. Distributed Energy Systems with Wind Power and Energy Storage

    OpenAIRE

    Korpås, Magnus

    2004-01-01

    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 s...

  12. 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.

  13. 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

    2016-03-01

    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.

  14. Energy investment: The many lives of energy storage

    Science.gov (United States)

    Fumagalli, Elena

    2016-07-01

    Energy storage offers potential to support a changing electricity sector, but investors remain uncertain about its attractiveness. Analysis now shows that this can be overcome for battery technology by providing more than one storage service in a single facility.

  15. 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)

  16. 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).

  17. Oriented nanostructures for energy conversion and storage.

    Science.gov (United States)

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

    2008-01-01

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

  18. An Overview on Energy Storage Options for Renewable Energy Systems

    OpenAIRE

    Ajay Sharma

    2014-01-01

    Developing technology to store electrical energy so it can be available to meet demand whenever needed would represent a major breakthrough in electricity distribution. Helping to try and meet this goal, electricity storage devices can manage the amount of power required to supply customers at times when need is greatest, which is during peak load. This paper focuses on four storage technologies that can be used as storage for wind energy conversion system. For each storage te...

  19. Microstructured electrodes for electrochemical energy storage

    OpenAIRE

    Smith, Leland Cramer

    2015-01-01

    Lithium-ion batteries and electric double-layer capacitors are two types of electrochemical energy storage devices that are characterized by high energy density and high power density, respectively. While these technologies have been successfully applied in applications such as personal electronics and electric vehicles, the potential for microscale energy storage devices remains unrealized. In this dissertation novel materials and processing methods are introduced for the fabrication of micr...

  20. 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

    2016-04-01

    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/μm2 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/cm2 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.

  1. PC-Cluster based Storage System Architecture for Cloud Storage

    CERN Document Server

    Yee, Tin Tin

    2011-01-01

    Design and architecture of cloud storage system plays a vital role in cloud computing infrastructure in order to improve the storage capacity as well as cost effectiveness. Usually cloud storage system provides users to efficient storage space with elasticity feature. One of the challenges of cloud storage system is difficult to balance the providing huge elastic capacity of storage and investment of expensive cost for it. In order to solve this issue in the cloud storage infrastructure, low cost PC cluster based storage server is configured to be activated for large amount of data to provide cloud users. Moreover, one of the contributions of this system is proposed an analytical model using M/M/1 queuing network model, which is modeled on intended architecture to provide better response time, utilization of storage as well as pending time when the system is running. According to the analytical result on experimental testing, the storage can be utilized more than 90% of storage space. In this paper, two parts...

  2. 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

  3. 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

  4. 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)

  5. Energy storage in future power systems

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...... 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...... of renewable energy. Meanwhile, the insurance of power system stability through reduction of power gradients is of major importance even at lower penetration levels and some form of energy storage therefore seems unavoidable. A variety of technologies are available for storage of energy in the power system...

  6. Novel concepts of compressed air energy storage and thermo-electric energy storage

    OpenAIRE

    Kim, Young Min

    2012-01-01

    The interest in energy storage is currently increasing, especially from the perspectives of matching intermittent sources of renewable energy with customer demand and storing excess nuclear or thermal power during the daily cycle. Technologies to be considered for load leveling for large-scale energy systems, typically in the range of hours to days of discharge time, include pumped-storage hydroelectricity, compressed air energy storage (CAES), sodium sulfur (NaS) batteries, advanced absorben...

  7. Biosensors and Biofuel Cells based on Vertically Aligned Carbon Nanotubes for Integrated Energy Sensing, Generation, and Storage (SGS) Systems

    Science.gov (United States)

    Pandey, Archana; Prasad, Abhishek; Khin Yap, Yoke

    2010-03-01

    Diabetes is a growing health issue in the nation. Thus in-situ glucose sensors that can monitor the glucose level in our body are in high demand. Furthermore, it will be exciting if the excessive blood sugar can be converted into usable energy, and be stored in miniature batteries for applications. This will be the basis for an integrated energy sensing, generation, and storage (SGS) system in the future. Here we report the use of functionalized carbon nanotubes arrays as the glucose sensors as well as fuel cells that can convert glucose into energy. In principle, these devices can be integrated to detect excessive blood glucose and then convert the glucose into energy. They are also inline with our efforts on miniature 3D microbatteries using CNTs [1]. All these devices will be the basis for future SGS systems. Details of these results will be discussed in the meeting. [1] Wang et al., in 206^th Meeting of the Electrochemical Society, October 3-8, Honolulu, Hawaii (2004), Symposium Q1, abstract 1492. Y. K. Yap acknowledges supports from DARPA (DAAD17-03-C-0115), USDA (2007-35603-17740), and the Multi-Scale Technologies Institute (MuSTI) at MTU.

  8. Mixed Solutions of Electrical Energy Storage

    OpenAIRE

    Chioncel Cristian Paul; Chioncel Petru; Babescu Marius

    2012-01-01

    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.

  9. 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.

  10. Bidding strategy for an energy storage facility

    DEFF Research Database (Denmark)

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

    2016-01-01

    to maximize its profit, while the market operator aims at maximizing the social welfare. In this case, the storage facility adapts its strategic behavior to take advantage of market conditions. To model the imperfectly competitive market, a bi-level optimization model is implemented to present......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...

  11. 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.

  12. Modular Energy Storage System for Alternative Energy Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Janice [Magna Electronics Inc., Auburn Hills, MI (United States); Ervin, Frank [Magna Electronics Inc., Auburn Hills, MI (United States)

    2012-05-15

    An electrical vehicle environment was established to promote research and technology development in the area of high power energy management. The project incorporates a topology that permits parallel development of an alternative energy delivery system and an energy storage system. The objective of the project is to develop technologies, specifically power electronics, energy storage electronics and controls that provide efficient and effective energy management between electrically powered devices in alternative energy vehicles plugin electric vehicles, hybrid vehicles, range extended vehicles, and hydrogen-based fuel cell vehicles. In order to meet the project objectives, the Vehicle Energy Management System (VEMS) was defined and subsystem requirements were obtained. Afterwards, power electronics, energy storage electronics and controls were designed. Finally, these subsystems were built, tested individually, and integrated into an electric vehicle system to evaluate and optimize the subsystems performance. Phase 1 of the program established the fundamental test bed to support development of an electrical environment ideal for fuel cell application and the mitigation of many shortcomings of current fuel cell technology. Phase 2, continued development from Phase 1, focusing on implementing subsystem requirements, design and construction of the energy management subsystem, and the integration of this subsystem into the surrogate electric vehicle. Phase 2 also required the development of an Alternative Energy System (AES) capable of emulating electrical characteristics of fuel cells, battery, gen set, etc. Under the scope of the project, a boost converter that couples the alternate energy delivery system to the energy storage system was developed, constructed and tested. Modeling tools were utilized during the design process to optimize both component and system design. This model driven design process enabled an iterative process to track and evaluate the impact

  13. Energy Storage:Maximising Irelands Wind Energy Potential

    OpenAIRE

    Kelly, Damien

    2010-01-01

    Ireland plan's to generate up to 40% of its electricity from wind generation by 2020. This thesis outlines the problems that may be faced by the electricity system and illustrates the benefits that large scale energy storage can bring to the electricity system when trying to integrate large amounts of wind energy. Energy storage is currently a topical subject in Ireland as wind penetration increases and problems such as curtailment loom. This thesis outlines the storage capacities required to...

  14. Simulation and evaluation of latent heat thermal energy storage

    Science.gov (United States)

    Sigmon, T. W.

    1980-01-01

    The relative value of thermal energy storage (TES) for heat pump storage (heating and cooling) as a function of storage temperature, mode of storage (hotside or coldside), geographic locations, and utility time of use rate structures were derived. Computer models used to simulate the performance of a number of TES/heat pump configurations are described. The models are based on existing performance data of heat pump components, available building thermal load computational procedures, and generalized TES subsystem design. Life cycle costs computed for each site, configuration, and rate structure are discussed.

  15. Composite Materials for Thermal Energy Storage: Enhancing Performance through Microstructures

    OpenAIRE

    Ge, Zhiwei; YE, Feng; Ding, Yulong

    2014-01-01

    Chemical incompatibility and low thermal conductivity issues of molten-salt-based thermal energy storage materials can be addressed by using microstructured composites. Using a eutectic mixture of lithium and sodium carbonates as molten salt, magnesium oxide as supporting material, and graphite as thermal conductivity enhancer, the microstructural development, chemical compatibility, thermal stability, thermal conductivity, and thermal energy storage performance of composite materials are inv...

  16. Nanocellulose and Polypyrrole Composites for Electrical Energy Storage

    OpenAIRE

    Nyström, Gustav

    2012-01-01

    To meet the predicted increase in demand for energy storage in tomorrow's society, the development of inexpensive, flexible, lightweight and sustainable energy-storage materials is essential. In this respect, devices based on electroactive organic molecules, such as conducting polymers, are highly interesting. The aim of this thesis was to evaluate the use of nanocellulose as a matrix material in composites of cellulose and the electroactive polymer polypyrrole (PPy), and the use of these com...

  17. 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.

  18. Demand Response and Energy Storage Integration Study

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ookie [Dept. of Energy (DOE), Washington DC (United States). Office of Energy Efficiency and Renewable Energy; Cheung, Kerry [Dept. of Energy (DOE), Washington DC (United States). Office of Electricity Delivery and Energy Reliability; Olsen, Daniel J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Matson, Nance [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sohn, Michael D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rose, Cody M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dudley, Junqiao Han [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Goli, Sasank [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kiliccote, Sila [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cappers, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); MacDonald, Jason [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Denholm, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hummon, Marissa [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jorgenson, Jennie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Palchak, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Starke, Michael [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Alkadi, Nasr [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bhatnagar, Dhruv [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Currier, Aileen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hernandez, Jaci [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kirby, Brendan [Consultant; O' Malley, Mark [Univ. College, Dublin (Ireland)

    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.

  19. Energy Storage (II): Developing Advanced Technologies

    Science.gov (United States)

    Robinson, Arthur L

    1974-01-01

    Energy storage, considered by some scientists to be the best technological and economic advancement after advanced nuclear power, still rates only modest funding for research concerning the development of advanced technologies. (PEB)

  20. Evaluation of Energy Storage System Based on PROMETHEE-GAIA%基于PROMETHEE-GAIA方法的储能方式评价

    Institute of Scientific and Technical Information of China (English)

    周阳; 张建成; 鲍雪娜; 李金鑫

    2012-01-01

    In the construction of smart grid,the choice of energy storage system is a multi-rule-based decision.The paper analyzes characteristics of the existing energy storage system and presents a PROMETHEE-GAIA(preference ranking organization methods and geometrical analysis) method.Taking the factors,such as technology of maturity, cost,service life,efficiency,response ability and environment as assessment criterion,a comprehensive evaluation for the existing energy storage systems is made,and the effects of the result as the changing rule-weights are analyzed and evaluated.Through the evaluation,this method is proven to have actual reference to selecting energy storage system.%智能电网中储能方式的选择是一个涉及多个评价准则的目标决策问题,在分析现有储能系统特点的基础上,提出一种PROMETHEE-GAIA方法(偏好顺序结构法与交互辅助几何分析法),以技术成熟程度、成本、寿命、效率、响应能力及环境因素作为目标的评价准则,对现有的储能方式做出综合评价,并分析评价准则权重变化时对结果的影响。通过此方法得出的综合排序结果对如何选择储能形态具有一定的实际指导意义。

  1. 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...

  2. Economic Modeling of Compressed Air Energy Storage

    OpenAIRE

    Rui Bo; Ming Ni; Yang Gu; James McCalley

    2013-01-01

    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-optimizatio...

  3. 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

  4. 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.

  5. Review of Magnetic Flywheel Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Prince Owusu-Ansah

    2014-08-01

    Full Text Available This study studies an overview of magnetic flywheel energy storage system. Energy storage is an integral part of any critical power system, as this stored energy is used to offset interruptions in the power delivered system from either a utility or an on-site generator. Magnetic flywheel as mechanical batteries using composite rotor, magnetic support bearings as well as power electronics to store electrical energy to replace stone wheel and chemical batteries has resulted in high power and energy densities. Traditionally, capacitors are used for short term storage (µs-ms and filtering, chemical batteries are used for intermediate storage (min-h and diesel fuel is used for long-term storage (h-days. Electricity generated from renewable sources, which has shown remarkable growth worldwide, can rarely provide immediate response to demand as these sources do not deliver regular supply easily adjustable to consumption needs. Thus, the growth of this decentralization production means greater network load stability problems and requires energy storage, generally using lead acid batteries as a potential solution. Finally the integration of all subsystems optimally of the magnetic flywheel system has resulted in a mechanical battery which can supply more efficient, reliable and uninterrupted power to meet the ever increasing demand of industrial machinery and automobiles.

  6. 三套管蓄能型热泵的制冷实验%Refrigeration Performance of the Triple-Sleeve Energy Storage Exchanger Based Energy Storage Heat Pump

    Institute of Scientific and Technical Information of China (English)

    曲德虎; 倪龙; 姚杨; 牛福新

    2016-01-01

    To perceive cooling behaviors of the triple-sleeve energy storage exchanger(TRESE)based energy storage heat pump system,a 2,HP prototype was manufactured and run to manifest the cooling performance of the novel sys-tem. Experiments included four operation modes under space cooling state. Results reflect that cooling cycle COP is from 2.4 to 3.7 when dry bulb temperature is lower than 25,℃ during nighttime. COP of TRESE cooling combined with air source heat pump is from 2.4 to 2.9 as outdoor dry bulb temperature is from 35 to 43,℃,which rises by 15%more than that of space cooling by air source heat pump only. When flow rate of cold water through TRESE is 40,L/h,the cooling rate of TRESE in combined cooling is 7.7% with scarcely wave,even with ambient tempera-ture changes. If opening all three TRESEs,the cooling rate of TRESE in combined cooling will be increased up to 23%.%为考察三套管蓄能型热泵(TRESE)的制冷性能,对一台2,HP样机的4种制冷模式分别进行了实验研究.实验结果表明,夜间室外干球温度低于25,℃时,三套管蓄能型热泵的周期制冷COP较高,其值在2.4~3.7之间;三套管蓄能器与空气源热泵联合供冷模式的COP较高,在室外干球温度为35~43,℃的范围内,其值在2.4~2.9之间,较空气源热泵单独供冷模式的COP提高了15%;当三套管蓄能器供冷水流量为40,L/h时,联合供冷期间三套管蓄能器的供冷百分比稳定在7.7%左右,受室外气温的影响不大;若将样机中3组三套管蓄能器同时开启,则三套管蓄能器的供冷率在联合供冷中的比例可提升至23%.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Storage, a stake for renewable energies integration

    International Nuclear Information System (INIS)

    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. Energy storage systems - Characteristics and comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, H. [Wind Energy Research Laboratory (WERL), Universite du Quebec a Rimouski, 300 allee des Ursulines, Que. (Canada); Anti Icing Materials International Laboratory (AMIL), Universite du Quebec a Chicoutimi, 555 boulevard de l' Universite, Que. (Canada); Ilinca, A. [Wind Energy Research Laboratory (WERL), Universite du Quebec a Rimouski, 300 allee des Ursulines, Que. (Canada); Perron, J. [Anti Icing Materials International Laboratory (AMIL), Universite du Quebec a Chicoutimi, 555 boulevard de l' Universite, Que. (Canada)

    2008-06-15

    Electricity generated from renewable sources, which has shown remarkable growth worldwide, can rarely provide immediate response to demand as these sources do not deliver a regular supply easily adjustable to consumption needs. Thus, the growth of this decentralized production means greater network load stability problems and requires energy storage, generally using lead batteries, as a potential solution. However, lead batteries cannot withstand high cycling rates, nor can they store large amounts of energy in a small volume. That is why other types of storage technologies are being developed and implemented. This has led to the emergence of storage as a crucial element in the management of energy from renewable sources, allowing energy to be released into the grid during peak hours when it is more valuable. The work described in this paper highlights the need to store energy in order to strengthen power networks and maintain load levels. There are various types of storage methods, some of which are already in use, while others are still in development. We have taken a look at the main characteristics of the different electricity storage techniques and their field of application (permanent or portable, long- or short-term storage, maximum power required, etc.). These characteristics will serve to make comparisons in order to determine the most appropriate technique for each type of application. (author)

  15. 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

  16. 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.

  17. Value of Energy Storage for Grid Applications (Report Summary) (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-06-01

    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.

  18. A novel flexible and modular energy storage system for near future Energy Banks

    OpenAIRE

    Fargion, Daniele; Habib, Emanuele

    2016-01-01

    We considered a novel energy storage system based on the compression of air through pumped water. Differently from CAES on trial, the proposed indirect compression leaves the opportunity to choose the kind of compression from adiabatic to isothermal. The energy storage process could be both fast or slow leading to different configuration and applications. These novel storage system are modular and could be applied in different scales for different locations and applications, being very flexib...

  19. Performance assessment and optimization of a combined heat and power system based on compressed air energy storage system and humid air turbine cycle

    International Nuclear Information System (INIS)

    Highlights: • A combined heat and power system based on CAES and HAT is proposed. • The design and modeling of the CAES–HAT based CHP system are laid out. • The performance assessment of the proposed system is carried out. • The system optimization is conducted to decide the maximum conditions. - Abstract: Renewable energy based power sources have grown rapidly in the past few years owing to the dual constraint of climate change and pollution control. Compressed air energy storage (CAES), as a large-scale energy storage system (ESS) technology, has huge potential to manage the intermittent renewable energy based power sources effectively. However, the compression heat generated during charge and waste heat carried in turbine exhaust during discharge are not fully recuperated in current stage. A combined heat and power (CHP) system consisting of a CAES system and a humid air turbine (HAT) system is proposed to utilize the both types of heat energy. The proposed system can boost the power output, enhance performance and improve efficiency through a simultaneous supply of power and heat. The thermodynamic analysis shows that the expansion train power can be improved about 26% compared with the conventional CAES system. The parametric analysis reveals that the exergy efficiency increases with the turbine inlet temperature (TIT) of high pressure turbine (HPT) and inlet pressure of low pressure turbine (LPT), but decreases with the TIT of LPT, L/G ratio and dry air inlet temperature of saturator. Meanwhile, the system optimization is carried out via particle swarm optimization (PSO) to determine the maximum power and exergy efficiency conditions

  20. The economics of energy storage in 14 deregulated power markets

    International Nuclear Information System (INIS)

    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

  1. 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 ...

  2. 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.

    2015-06-01

    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 alumina and

  3. 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.

  4. Progress in electrical energy storage system:A critical review

    Institute of Scientific and Technical Information of China (English)

    Haisheng Chen; Thang Ngoc Cong; Wei Yang; Chunqing Tan; Yongliang Li; Yulong Ding

    2009-01-01

    Electrical energy storage technologies for stationary applications are reviewed.Particular attention is paid to pumped hydroelectric storage,compressed air energy storage,battery,flow battery,fuel cell,solar fuel,superconducting magnetic energy storage, flywheel, capacitor/supercapacitor,and thermal energy torage.Comparison is made among these technologies in terms of technical characteris-tics,applications and deployment status.

  5. 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

  6. 储氢技术综述及在氢储能中的应用展望%Overview of Hydrogen Storage Technologies and Their Application Prospects in Hydrogen-based Energy Storage

    Institute of Scientific and Technical Information of China (English)

    徐丽; 马光; 盛鹏; 李瑞文; 刘志伟; 李平

    2016-01-01

    氢储能技术是解决大规模风电储存的一种新途径,高效储氢技术是氢储能系统得以应用的关键环节之一。综述储氢技术的国内外研究进展,对适于商业应用的高压气态储氢技术、低温液态储氢技术、金属氢化物储氢技术,以及低温高压、高压金属氢化物复合储氢技术展开比较和分析。通过对氢储能系统应用过程的分析,认为氢储能系统对储氢技术的要求,更侧重于安全性、成本和体积密度。综合考虑各种储氢方式在氢储能应用上的优缺点,认为金属氢化物储氢技术和高压金属氢化物储氢技术具有显著的优势。%Hydrogen storage technology is a new way to solve large-scale wind power storage, and high efficient hydrogen storage technology is one of the key links in the application of hydrogen energy storage system. This paper reviews its domestic and foreign research progresses of hydrogen storage technology. Comparative analysis of high pressure gaseous hydrogen storage technology, cryogenic liquid hydrogen storage technology, metal hydride hydrogen storage technology, cryogenic high pressure and high-pressure metal hydride composite hydrogen storage technology for commercial application is carried out. According to the analysis of hydrogen energy storage system’s application process, it could be deemed that the requirements of hydrogen energy storage system for hydrogen storage technology are more focused on safety, cost and volume density. The advantages and disadvantages of various hydrogen storage ways in hydrogen energy storage applications are synthetically considered. It can draw the conclusion that metal hydride hydrogen storage technology and high-pressure metal hydride hydrogen storage technology have remarkable advantages.

  7. 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. PMID:27097913

  8. 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.

  9. Energy storage: Redox Flow Batteries Go Organic

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Sprenkle, Vincent L.

    2016-02-19

    Access to sustainable and affordable energy is the foundation for the economic growth of our current society and its future prosperity. Energy harvested from renewable resources, such as solar and wind, although currently at a small fraction, is on a steady trajectory of increasing installation accompanied with falling cost. Driven also by the need to reduce the carbon footprint from electricity generation, they could provide a clean and sustainable energy future. The caveat, however, is the intermittent and fluctuating nature of the renewables, which threatens the stability of the grid when its share surpasses 20% of the overall energy capacity. 1 Besides the on-demand power generation, electrical energy storage is another potentially cost-effective way to provide massive energy storage for not only renewable energy integration, but to balance the mismatch between supply and demand, and the improvement of grid reliability and efficiency also.

  10. 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. PMID:26629882

  11. 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.

  12. Economic models for battery energy storage

    International Nuclear Information System (INIS)

    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

  13. 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.

  14. Compressed Air Energy Storage System Control and Performance Assessment Using Energy Harvested Index

    OpenAIRE

    Hanif SedighNejad; Tariq Iqbal; John Quaicoe

    2014-01-01

    In this paper a new concept for control and performance assessment of compressed air energy storage (CAES) systems in a hybrid energy system is introduced. The proposed criterion, based on the concept of energy harvest index (HEI), measures the capability of a storage system to capture renewable energy. The overall efficiency of the CAES system and optimum control and design from the technical and economic point of view is presented. A possible application of this idea is an isolated communit...

  15. 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. [...

  16. Underground-Energy-Storage Program, 1982 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Kannberg, L.D.

    1983-06-01

    Two principal underground energy storage technologies are discussed--Seasonal Thermal Energy Storage (STES) and Compressed Air Energy Storage (CAES). The Underground Energy Storage Program objectives, approach, structure, and milestones are described, and technical activities and progress in the STES and CAES areas are summarized. STES activities include aquifer thermal energy storage technology studies and STES technology assessment and development. CAES activities include reservoir stability studies and second-generation concepts studies. (LEW)

  17. 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.

  18. An energy storage and regeneration system

    DEFF Research Database (Denmark)

    2006-01-01

    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 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...... the higher level of energy demand....

  19. Development of thermal energy storage concrete

    Energy Technology Data Exchange (ETDEWEB)

    Dong Zhang; Jianmin Zhou; Keru Wa [Tongji Univ., Shanghai (China). State Key Lab. of Concrete Materials Research; Zongjin Li [Hong Kong Univ. of Science and Technology, Kowloon (China). Dept. of Civil Engineering

    2004-06-01

    In this paper, a two-step procedure to produce thermal energy storage concrete (TESC) is described. At the first step, thermal energy storage aggregates (TESAs) were made from porous aggregates absorbing phase changing materials (PCMs). At the second step, TESC was produced with a normal mixing method and using TESAs. An adequate amount of PCM can be incorporated into concrete by the two-step procedure. It can be seen experimentally that the energy storage capacity of the TESC was comparable with that of a commercially available PCM. The experimental results showed that the geometrical features of the porous structure of the aggregates had significant effect on their absorbing ability of the PCM. Aggregates with large pore connectivity factor and transport tunnel in boundary part can absorb more PCM. It was also found that the phase changing behavior was affected by the volume fraction of PCM in concrete. (Author)

  20. Development of an energy storage tank model

    Science.gov (United States)

    Buckley, Robert Christopher

    A linearized, one-dimensional finite difference model employing an implicit finite difference method for energy storage tanks is developed, programmed with MATLAB, and demonstrated for different applications. A set of nodal energy equations is developed by considering the energy interactions on a small control volume. The general method of solving these equations is described as are other features of the simulation program. Two modeling applications are presented: the first using a hot water storage tank with a solar collector and an absorption chiller to cool a building in the summer, the second using a molten salt storage system with a solar collector and steam power plant to generate electricity. Recommendations for further study as well as all of the source code generated in the project are also provided.

  1. 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.

  2. Engineered nanomembranes for smart energy storage devices.

    Science.gov (United States)

    Wang, Xianfu; Chen, Yu; Schmidt, Oliver G; Yan, Chenglin

    2016-03-01

    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.

  3. Electroactive graphene nanofluids for fast energy storage

    Science.gov (United States)

    Dubal, Deepak P.; Gomez-Romero, Pedro

    2016-09-01

    Graphenes have been extensively studied as electrode materials for energy storage in supercapacitors and batteries, but always as solid electrodes. The conception and development of graphene electroactive nanofluids (ENFs) reported here for the first time provides a novel way to ‘form’ graphene electrodes and demonstrates proof of concept for the use of these liquid electrodes for energy storage in novel flow cells. A stabilized dispersion of reduced graphene oxide (rGO) in aqueous sulfuric acid solution was shown to have capacitive energy storage capabilities parallel to those of solid electrode supercapacitors (169 F g-1(rGO)) but working up to much faster rates (from 1 mV s-1 to the highest scan rate of 10 V s-1) in nanofluids with 0.025, 0.1 and 0.4 wt% rGO, featuring viscosities very close to that of water, thus being perfectly suitable for scalable flow cells. Our results provide proof of concept for this technology and include preliminary flow cell performance of rGO nanofluids under static and continuous flow conditions. Graphene nanofluids effectively behave as true liquid electrodes with very fast capacitive storage mechanism and herald the application not only of graphenes but also other 2D materials like MoS2 in nanofluids for energy storage and beyond.

  4. Electroactive graphene nanofluids for fast energy storage

    Science.gov (United States)

    Dubal, Deepak P.; Gomez-Romero, Pedro

    2016-09-01

    Graphenes have been extensively studied as electrode materials for energy storage in supercapacitors and batteries, but always as solid electrodes. The conception and development of graphene electroactive nanofluids (ENFs) reported here for the first time provides a novel way to ‘form’ graphene electrodes and demonstrates proof of concept for the use of these liquid electrodes for energy storage in novel flow cells. A stabilized dispersion of reduced graphene oxide (rGO) in aqueous sulfuric acid solution was shown to have capacitive energy storage capabilities parallel to those of solid electrode supercapacitors (169 F g‑1(rGO)) but working up to much faster rates (from 1 mV s‑1 to the highest scan rate of 10 V s‑1) in nanofluids with 0.025, 0.1 and 0.4 wt% rGO, featuring viscosities very close to that of water, thus being perfectly suitable for scalable flow cells. Our results provide proof of concept for this technology and include preliminary flow cell performance of rGO nanofluids under static and continuous flow conditions. Graphene nanofluids effectively behave as true liquid electrodes with very fast capacitive storage mechanism and herald the application not only of graphenes but also other 2D materials like MoS2 in nanofluids for energy storage and beyond.

  5. 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

  6. Nonlinear phenomenon in monocrystalline silicon based PV module for low power system: Lead acid battery for low energy storage

    Science.gov (United States)

    El Amrani, A.; El Amraoui, M.; El Abbassi, A.; Messaoudi, C.

    2014-11-01

    In the present work, we report the indoor photo-electrical measurements of monocrystalline silicon based photovoltaic (PV) module associated with 4 Ah lead acid battery as a storage unit for low power PV system applications. Concerning the PV module, our measurements show, at low illumination regime, that the short circuit current ISC increases linearly with the illumination power levels. Moreover, for high illumination levels, the mechanism of bimolecular recombination and space charge limitation may be intensified and hence the short current of the PV module ISCMod depends sublinearly on the incident optical power; the behavior is nonlinear. For the open circuit voltage of the PV module VOCMod measurements, a linear variation of the VOCMod versus the short circuit current in semi-logarithmic scale has been noticed. The diode ideality factor n and diode saturation current Is have been investigated; the values of n and Is are approximately of 1.3 and 10-9 A, respectively. In addition, we have shown, for different discharging-charging currents rates (i.e. 0.35 A, 0.2 A and 0.04 A), that the battery voltage decreases with discharging time as well as discharging battery capacity, and on the other hand it increases with the charging time and will rise up until it maximized value. The initial result shows the possibility to use such lead acid battery for low power PV system, which is generally designed for the motorcycle battery.

  7. On generation-integrated energy storage

    OpenAIRE

    Garvey, S.D.; Eames, P.C; Wang, J. H.; Pimm, A.J.; Waterson, M; MacKay, R. S.; M. Giulietti; Flatley, L.C.; Thomson, M.; Barton, J.; Evans, D. J.; Busby, J; Garvey, J.E.

    2015-01-01

    Generation-integrated energy storage (GIES) systems store energy at some point along the transformation between the primary energy form and electricity. Instances exist already in natural hydro power, biomass generation, wave power, and concentrated solar power. GIES systems have been proposed for wind, nuclear power and they arise naturally in photocatalysis systems that are in development. GIES systems can compare very favourably in both performance and total cost against equivalent non-int...

  8. Adiabatic Liquid Piston Compressed Air Energy Storage

    OpenAIRE

    Petersen, Tage; Elmegaard, Brian; Pedersen, Allan Schrøder

    2013-01-01

    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, ...

  9. 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)

  10. TEE-Based Trusted Storage

    DEFF Research Database (Denmark)

    Gonzalez, Javier; Bonnet, Philippe

    trusted storage for personal data. We believe that this role can be taken over by systems equipped with Trusted Execution Environments (TEE), such as ARM’s TrustZone. Indeed, even if TEEs provide weaker security guarantees than crypto-processors, they already provide a secure area on many personal devices......Today, it is safe to assume that any program or data can be compromised, if they are not protected by hardware within a secure area. Systems based on crypto-processors (e.g., a trusted platform module, a smart card or a hardware security module) rely on the properties of tamper resistant hardware...... to establish a tight security parameter around a reduced set of predefined functionalities. Such systems are very secure, but they impose strong constraints on the functionalities, the connectivity or the resources available within the secure area. They have not proven versatile enough to provide mainstream...

  11. Energy storage system control strategies for power distribution systems

    Directory of Open Access Journals (Sweden)

    Areewan Kajorndech

    2015-03-01

    Full Text Available Energy storage systems have been widely employed to attain several benefits, such as reliability improvement, stabilization of power systems connected with renewable energy resources, economic benefits and etc. To achieve the above objectives, the appropriate and effective control strategies for energy storage systems are needed to be developed. This research proposes energy storage system control strategies for power distribution systems equipped with a limited size of energy storage system in order to improve reliability and save energy costs by determining an optimal charging schedule of the energy storage system. Simulation results demonstrate the benefits of energy storage system applications under the different control strategies.

  12. Solar energy collector and storage device

    Energy Technology Data Exchange (ETDEWEB)

    Smith, H.T.

    1979-08-28

    An improved flat plate solar energy collector of integral construction capable of mass production in which metal tubing is eliminated is described. The collector includes a stamped planar tray and a radiant energy absorber plate connected together to form the inlet and outlet fluid header and the innerconnecting channels therebetween. The planar tray and absorber plate are mounted in a molded insulated housing which integrally includes a storage tank. A fluid medium such as water is heated by solar radiation and circulated through the collector to the storage tank by thermal syphon. Elimination of conventional tubing greatly reduces fabrication costs and increases absorption efficiency.

  13. 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...... the prices from fluctuating to the extent that CAES investments have not been considered feasible. This report studies the effect of technological development and possible future price development of investments in CAES plants of various capacities. It is found that advanced high-efficiency CAES plants...

  14. 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.

  15. Mathematical modeling of moving boundary problems in thermal energy storage

    Science.gov (United States)

    Solomon, A. D.

    1980-01-01

    The capability for predicting the performance of thermal energy storage (RES) subsystems and components using PCM's based on mathematical and physical models is developed. Mathematical models of the dynamic thermal behavior of (TES) subsystems using PCM's based on solutions of the moving boundary thermal conduction problem and on heat and mass transfer engineering correlations are also discussed.

  16. A novel flexible and modular energy storage system for near future Energy Banks

    CERN Document Server

    Fargion, Daniele

    2016-01-01

    We considered a novel energy storage system based on the compression of air through pumped water. Differently from CAES on trial, the proposed indirect compression leaves the opportunity to choose the kind of compression from adiabatic to isothermal. The energy storage process could be both fast or slow leading to different configuration and applications. These novel storage system are modular and could be applied in different scales for different locations and applications, being very flexible in charge and discharge process. The system may offer an ideal energy buffer for wind and solar storage with no (or negligible) environment hazard. The main features of this novel energy storage system will be showed together with overall energy and power data.

  17. 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.

  18. Solar Thermal Energy Storage in a Photochromic Macrocycle.

    Science.gov (United States)

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

    2016-07-25

    The conversion and efficient storage of solar energy is recognized to hold significant potential with regard to future energy solutions. Molecular solar thermal batteries based on photochromic systems exemplify one possible technology able to harness and apply this potential. Herein is described the synthesis of a macrocycle based on a dimer of the dihydroazulene/vinylheptafulvene (DHA/VHF) photo/thermal couple. By taking advantage of conformational strain, this DHA-DHA macrocycle presents an improved ability to absorb and store incident light energy in chemical bonds (VHF-VHF). A stepwise energy release over two sequential ring-closing reactions (VHF→DHA) combines the advantages of an initially fast discharge, hypothetically addressing immediate energy consumption needs, followed by a slow process for consistent, long-term use. This exemplifies another step forward in the molecular engineering and design of functional organic materials towards solar thermal energy storage and release. PMID:27253462

  19. Solar Thermal Energy Storage in a Photochromic Macrocycle.

    Science.gov (United States)

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

    2016-07-25

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

  20. A review on packed bed solar energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Harmeet; Saini, R.P. [Alternate Hydro Energy Centre, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Saini, J.S. [Mechanical and Industrial Engineering Department, Indian Institute of Technology Roorkee, Roorkee 247667 (India)

    2010-04-15

    Because of intermittent nature of solar energy, storage is required for uninterrupted supply in order to match the needs. Packed beds are generally used for storage of thermal energy from solar air heaters. A packed bed is a volume of porus media obtained by packing particles of selected material into a container. A number of studies carried out on packed beds for their performance analysis were reported in the literature. These studies included the design of packed beds, materials used for storage, heat transfer enhancement, flow phenomenon and pressure drop through packed beds. This paper presents an extensive review on the research carried out on packed beds. Based on the literature review, it is concluded that most of the studies carried out are on rocks and pebbles as packing material. A very few studies were conducted on large sized packing materials. Further no study has been reported so far on medium sized storage elements in packed beds. (author)

  1. 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.

  2. Energy storage, compression, and switching. Vol. 2

    International Nuclear Information System (INIS)

    This book is a compilation of papers presented at the Second International Conference on Energy Storage, Compression, and Switching, which was held in order to assemble active researchers with a major interest in plasma physics, electron beams, electric and magnetic energy storage systems, high voltage and high current switches, free-electron lasers, and pellet implosion plasma focus. Topics covered include: Slow systems: 50-60 Hz machinery, homopolar generators, slow capacitors, inductors, and solid state switches; Intermediate systems: fast capacitor banks; superconducting storage and switching; gas, vacuum, and dielectric switching; nonlinear (magnetic) switching; imploding liners capacitors; explosive generators; and fuses; and Fast systems: Marx, Blumlein, oil, water, and pressurized water dielectrics; switches; magnetic insulation; electron beams; and plasmas

  3. 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 e...

  4. Electric Vehicles Mileage Extender Kinetic Energy Storage

    Directory of Open Access Journals (Sweden)

    Jivkov Venelin

    2015-03-01

    Full Text Available 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.

  5. Evaluation of solar thermal storage for base load electricity generation

    OpenAIRE

    Adinberg R.

    2012-01-01

    In order to stabilize solar electric power production during the day and prolong the daily operating cycle for several hours in the nighttime, solar thermal power plants have the options of using either or both solar thermal storage and fossil fuel hybridization. The share of solar energy in the annual electricity production capacity of hybrid solar-fossil power plants without energy storage is only about 20%. As it follows from the computer simulations performed for base load electricity dem...

  6. Evaluation of thermal energy storage for the proposed Twin Cities District Heating system. [using cogeneration heat production and aquifiers for heat storage

    Science.gov (United States)

    Meyer, C. F.

    1980-01-01

    The technical and economic feasibility of incorporating thermal energy storage components into the proposed Twin Cities District heating project was evaluated. The technical status of the project is reviewed and conceptual designs of district heating systems with and without thermal energy storage were compared in terms of estimated capital requirements, fuel consumption, delivered energy cost, and environmental aspects. The thermal energy storage system is based on cogeneration and the storage of heat in aquifers.

  7. 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 reactions. The inter

  8. Superconducting Magnetic Energy Storage and Applications

    Science.gov (United States)

    Rao, V. Vasudeva

    2008-10-01

    This paper gives an Introduction to Superconducting Magnetic Energy Storage (SMES) systems and their applications along with an overview of their present status. Further a brief description to a Micro SMES/UPS system of 0.5 MJ capacity that was developed/tested at IIT, Kharagpur is also included.

  9. 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…

  10. Fuel Cells and Electrochemical Energy Storage.

    Science.gov (United States)

    Sammells, Anthony F.

    1983-01-01

    Discusses the nature of phosphoric acid, molten carbonate, and solid oxide fuel cells and major features and types of batteries used for electrical energy storage. Includes two tables presenting comparison of major battery features and summary of major material problems in the sodium-sulfur and lithium-alloy metal sulfide batteries. (JN)

  11. 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...... a turbine when discharging. In this case, the liquid works effectively as a piston compressing the gas in the vessel, hence the name “Adiabatic Liquid Piston Compressed Air Energy Storage” (ALP-CAES). The compression ratio of the gas in the vessel (ratio between maximum and minimum pressure) is relatively...

  12. The Role of Energy Storages in Energy Independent Croatia

    DEFF Research Database (Denmark)

    Krajačić, Goran; Mathiesen, Brian Vad; Duić, Neven;

    2009-01-01

    electricity, heat and transport demands, and including renewable energy, power plants, and combined heat and power production (CHP) for district heating. Using the 2007 energy system the wind power share is increased by two energy storage options: Pumped Hydro and Heat Pumps in combination with Heat Storages....... The results show that such options can enable an increased penetration of wind power. Using pumped hydro storage (PHS) may increase wind power penetration from 0.5 TWh, for existing PHS installations and up to 6 TWh for very large installations. Using large heat pumps and heat storages in combination...... with specific regulation of power system could additionally increase wind penetration for 0.37 TWh. Hence, with the current technologies installed in the Croatian energy system the installed pumped hydro- plant may facilitate more than 10% wind power in the electricity system. In future research more precise...

  13. A High-Efficiency Grid-Tie Battery Energy Storage System

    OpenAIRE

    Qian, Hao

    2011-01-01

    Lithium-ion based battery energy storage system has become one of the most popular forms of energy storage system for its high charge and discharge efficiency and high energy density. This dissertation proposes a high-efficiency grid-tie lithium-ion battery based energy storage system, which consists of a LiFePO4 battery based energy storage and associated battery management system (BMS), a high-efficiency bidirectional ac-dc converter and the central control unit which controls the operation...

  14. 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.

  15. 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.

  16. 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...

  17. 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

  18. 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)

  19. 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...

  20. Simulation of thermocline thermal energy storage system using C

    Directory of Open Access Journals (Sweden)

    Meseret Tesfay

    2013-06-01

    Full Text Available Solar thermal power generation is a modern technology, which has already shown feasible results in the production of electricity. Thermal energy storage (TES is a crucial element in solar energy applications, which includes the increase of building thermal capacity, solar water heating systems for domestic use, and Concentrated Solar Thermal power plants for electricity generation. Economic, efficient and reliable thermal energy storage systems are a key need of solar thermal power plants, in order to smooth out the insolation changes during intermittent cloudy weather condition or during night period, to allow the operation. To address this goal, based on the parabolic trough power plants, sensible heat storage system with operation temperature between 300°C – 390°C can be used. The goal of this research is to design TES which can produce 1MWe. In this work simulation is performed to analyze the Liquid medium STES using C. In this case different liquid medium TESs is investigated and out of all mixed-media single-tank thermocline TES is selected and designed based on the Schumann equation. In particular, this equation is numerically solved, in order to determine energy storage, at different locations and time inside the storage tank. Finally, due to their feasibility, low cost of manufacturing and maintenance are designed and sized to the minimum possible volume.

  1. 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. PMID:24913891

  2. 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.

  3. Organo-sulfur molecules enable iron-based battery electrodes to meet the challenges of large-scale electrical energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Yang, B; Malkhandi, S; Manohar, AK; Prakash, GKS; Narayanan, SR

    2014-07-03

    Rechargeable iron-air and nickel-iron batteries are attractive as sustainable and inexpensive solutions for large-scale electrical energy storage because of the global abundance and eco-friendliness of iron, and the robustness of iron-based batteries to extended cycling. Despite these advantages, the commercial use of iron-based batteries has been limited by their low charging efficiency. This limitation arises from the iron electrodes evolving hydrogen extensively during charging. The total suppression of hydrogen evolution has been a significant challenge. We have found that organo-sulfur compounds with various structural motifs (linear and cyclic thiols, dithiols, thioethers and aromatic thiols) when added in milli-molar concentration to the aqueous alkaline electrolyte, reduce the hydrogen evolution rate by 90%. These organo-sulfur compounds form strongly adsorbed layers on the iron electrode and block the electrochemical process of hydrogen evolution. The charge-transfer resistance and double-layer capacitance of the iron/electrolyte interface confirm that the extent of suppression of hydrogen evolution depends on the degree of surface coverage and the molecular structure of the organo-sulfur compound. An unanticipated electrochemical effect of the adsorption of organo-sulfur molecules is "de-passivation" that allows the iron electrode to be discharged at high current values. The strongly adsorbed organo-sulfur compounds were also found to resist electro-oxidation even at the positive electrode potentials at which oxygen evolution can occur. Through testing on practical rechargeable battery electrodes we have verified the substantial improvements to the efficiency during charging and the increased capability to discharge at high rates. We expect these performance advances to enable the design of efficient, inexpensive and eco-friendly iron-based batteries for large-scale electrical energy storage.

  4. Energy storage system control strategies for power distribution systems

    OpenAIRE

    Areewan Kajorndech; Dulpichet Rerkpreedapong

    2015-01-01

    Energy storage systems have been widely employed to attain several benefits, such as reliability improvement, stabilization of power systems connected with renewable energy resources, economic benefits and etc. To achieve the above objectives, the appropriate and effective control strategies for energy storage systems are needed to be developed. This research proposes energy storage system control strategies for power distribution systems equipped with a limited size of energy storage system ...

  5. 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

  6. Battery Energy Storage System for PV Output Power Leveling

    OpenAIRE

    Rajkiran Singh; Seyedfoad Taghizadeh; Nadia Mei Lin Tan; Jagadeesh Pasupuleti

    2014-01-01

    Fluctuating photovoltaic (PV) output power reduces the reliability in power system when there is a massive penetration of PV generators. Energy storage systems that are connected to the PV generators using bidirectional isolated dc-dc converter can be utilized for compensating the fluctuating PV power. This paper presents a grid connected energy storage system based on a 2 kW full-bridge bidirectional isolated dc-dc converter and a PWM converter for PV output power leveling. This paper propos...

  7. Alkaline regenerative fuel cell systems for energy storage

    Science.gov (United States)

    Schubert, F. H.; Reid, M. A.; Martin, R. E.

    1981-01-01

    A description is presented of the results of a preliminary design study of a regenerative fuel cell energy storage system for application to future low-earth orbit space missions. The high energy density storage system is based on state-of-the-art alkaline electrolyte cell technology and incorporates dedicated fuel cell and electrolysis cell modules. In addition to providing energy storage, the system can provide hydrogen and oxygen for attitude control of the satellite and for life support. During the daylight portion of the orbit the electrolysis module uses power provided by the solar array to generate H2 and O2 from the product water produced by the fuel cell module. The fuel cell module supplies electrical power during the dark period of the orbit.

  8. 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

    2014-01-01

    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.

  9. Flywheel Energy Storage Technology Being Developed

    Science.gov (United States)

    Wolff, Frederick J.

    2001-01-01

    A flywheel energy storage system was spun to 60,000 rpm while levitated on magnetic bearings. This system is being developed as an energy-efficient replacement for chemical battery systems. Used in groups, the flywheels can have two functions providing attitude control for a spacecraft in orbit as well as providing energy storage. The first application for which the NASA Glenn Research Center is developing the flywheel is the International Space Station, where a two-flywheel system will replace one of the nickel-hydrogen battery strings in the space station's power system. The 60,000-rpm development rotor is about one-eighth the size that will be needed for the space station (0.395 versus 3.07 kWhr).

  10. Progress in energy storage in the USA

    International Nuclear Information System (INIS)

    Deregulation and the emergence of a competitive marketplace for electricity are bringing many changes to the electric power industry in the United States. Traditional utilities are changing their business structure and new unregulated companies are entering the marketplace to compete for customers on the basis of cost and services. Increased strain on the transmission and distribution system may lead to reliability problems. These changes present many opportunities for energy storage technologies. U.S. industry and the Department of Energy are developing state-of-the-art energy storage systems that will minimize the cost to the U.S. economy due to power quality and reliability problems, enhance utility choices in a deregulated electricity marketplace and increase the value of renewable and distributed resources. (author)

  11. 混合储能超级电容与蓄电池能量分配策略研究%Energy Allocation Strategy of Super Capacitor and Storage Battery Based on Hybrid Energy Storage

    Institute of Scientific and Technical Information of China (English)

    曹华锋; 白迪; 赵志刚

    2016-01-01

    According to the hybrid energy storage capacity of micro grid, a dynamic control strategy for the DC⁃DC converter is pro⁃posed. This strategy can prevent the battery from the depth of discharge, reduce the battery charge and discharge frequency, extend the battery life. The effectiveness of the proposed strategy is verified by simulation.%针对超级电容与蓄电池的混合储能,提出了一种电池端DC-DC变换器动态控制策略。该策略可以防止电池出现深度放电,降低蓄电池的充放电频率,延长电池使用寿命,并通过仿真验证了其有效性。

  12. Energy storage reinforces competitive business practices

    International Nuclear Information System (INIS)

    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. 基于间接Hamilton化理论的超导储能控制设计%Superconducting Magnetic Energy Storage Controller Design Based on Indirect Hamilton Theory

    Institute of Scientific and Technical Information of China (English)

    陈毅然; 王杰

    2013-01-01

    采用超导储能装置(Superconducting magnetic energy storage,SMES)的二阶模型,得到含SMES的单机无穷大电力系统模型.进而利用Lagrange化和间接Hamilton化理论,构造了该动态系统的Hamilton函数,并提出相应的SMES的稳定控制策略.最后,利用Matlab进行仿真验证了笔者所提出控制律的正确性和有效性.结果表明,在大干扰的情况下,基于间接Hamilton化理论所设计的超导储能控制器能使系统快速地恢复到稳定运行状态,提高电力系统的暂态稳定性.%Considering the second order model of superconducting magnetic energy storage (SMES),this paper builds up a model of the single-machine infinite-bus system (SMIB) with SMES.Then based on the Lagrange theory and indirect Hamilton theory,the Hamiltonian energy function is constructed and corresponding control strategy is proposed.Finally,the correctness and efficiency of the controller is verified using the MATLAB software package.Simulation results manifest,under the large disturbances,that proposed control strategy can quickly make the system back to the stable operation state and improve the transient stability of the power system.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Energy Storage Systems Are Coming: Are You Ready

    Energy Technology Data Exchange (ETDEWEB)

    Conover, David R.

    2015-12-05

    Energy storage systems (batteries) are not a new concept, but the technology being developed and introduced today with an increasing emphasis on energy storage, is new. The increased focus on energy, environmental and economic issues in the built environment is spurring increased application of renewables as well as reduction in peak energy use - both of which create a need for energy storage. This article provides an overview of current and anticipated energy storage technology, focusing on ensuring the safe application and use of energy storage on both the grid and customer side of the utility meter.

  20. Look-Ahead Energy Management of a Grid-Connected Residential PV System with Energy Storage under Time-Based Rate Programs

    Directory of Open Access Journals (Sweden)

    Kyeon Hur

    2012-04-01

    Full Text Available This paper presents look-ahead energy management system for a grid-connected residential photovoltaic (PV system with battery under critical peak pricing for electricity, enabling effective and proactive participation of consumers in the Smart Grid’s demand response. In the proposed system, the PV is the primary energy source with the battery for storing (or retrieving excessive (or stored energy to pursue the lowest possible electricity bill but it is grid-tied to secure electric power delivery. Premise energy management scheme with an accurate yet practical load forecasting capability based on a Kalman filter is designed to increase the predictability in controlling the power flows among these power system components and the controllable electric appliances in the premise. The case studies with various operating scenarios demonstrate the validity of the proposed system and significant cost savings through operating the energy management scheme.

  1. 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.

  2. 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

  3. Simulation of Mechanical Processes in Gas Storage Caverns for Short-Term Energy Storage

    Science.gov (United States)

    Böttcher, Norbert; Nagel, Thomas; Kolditz, Olaf

    2015-04-01

    In recent years, Germany's energy management has started to be transferred from fossil fuels to renewable and sustainable energy carriers. Renewable energy sources such as solar and wind power are subjected by fluctuations, thus the development and extension of energy storage capacities is a priority in German R&D programs. This work is a part of the ANGUS+ Project, funded by the federal ministry of education and research, which investigates the influence of subsurface energy storage on the underground. The utilization of subsurface salt caverns as a long-term storage reservoir for fossil fuels is a common method, since the construction of caverns in salt rock is inexpensive in comparison to solid rock formations due to solution mining. Another advantage of evaporate as host material is the self-healing behaviour of salt rock, thus the cavity can be assumed to be impermeable. In the framework of short-term energy storage (hours to days), caverns can be used as gas storage reservoirs for natural or artificial fuel gases, such as hydrogen, methane, or compressed air, where the operation pressures inside the caverns will fluctuate more frequently. This work investigates the influence of changing operation pressures at high frequencies on the stability of the host rock of gas storage caverns utilizing numerical models. Therefore, we developed a coupled Thermo-Hydro-Mechanical (THM) model based on the finite element method utilizing the open-source software platform OpenGeoSys. The salt behaviour is described by well-known constitutive material models which are capable of predicting creep, self-healing, and dilatancy processes. Our simulations include the thermodynamic behaviour of gas storage process, temperature development and distribution on the cavern boundary, the deformation of the cavern geometry, and the prediction of the dilatancy zone. Based on the numerical results, optimal operation modes can be found for individual caverns, so the risk of host rock damage

  4. Palladium based nanomaterials for enhanced hydrogen spillover and storage

    Directory of Open Access Journals (Sweden)

    Suresh K. Konda

    2016-03-01

    Full Text Available Hydrogen storage remains one of the most challenging prerequisites to overcome toward the realization of a hydrogen based economy. The use of hydrogen as an energy carrier for fuel cell applications has been limited by the lack of safe and effective hydrogen storage materials. Palladium has high affinity for hydrogen sorption and has been extensively studied, both in the gas phase and under electrochemical conditions. In this review, recent advancements are highlighted and discussed in regard to palladium based nanomaterials for hydrogen storage, as well as the effects of hydrogen spillover on various adsorbents including carbons, metal organic frameworks, covalent organic frameworks, and other nanomaterials.

  5. 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.

  6. Residential Solar-Based Seasonal Thermal Storage Systems in Cold Climates: Building Envelope and Thermal Storage

    OpenAIRE

    Alexandre Hugo; Radu Zmeureanu

    2012-01-01

    The reduction of electricity use for heating and domestic hot water in cold climates can be achieved by: (1) reducing the heating loads through the improvement of the thermal performance of house envelopes, and (2) using solar energy through a residential solar-based thermal storage system. First, this paper presents the life cycle energy and cost analysis of a typical one-storey detached house, located in Montreal, Canada. Simulation of annual energy use is performed using the TRNSYS softwar...

  7. Comparing energy storage options for renewable energy integration

    OpenAIRE

    Østergaard, Poul Alberg

    2011-01-01

    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 de...

  8. CALORSTOCK'94. Thermal energy storage. Better economy, environment, technology

    International Nuclear Information System (INIS)

    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

  9. Overview of Probe-based Storage Technologies

    Science.gov (United States)

    Wang, Lei; Yang, Ci Hui; Wen, Jing; Gong, Si Di; Peng, Yuan Xiu

    2016-07-01

    The current world is in the age of big data where the total amount of global digital data is growing up at an incredible rate. This indeed necessitates a drastic enhancement on the capacity of conventional data storage devices that are, however, suffering from their respective physical drawbacks. Under this circumstance, it is essential to aggressively explore and develop alternative promising mass storage devices, leading to the presence of probe-based storage devices. In this paper, the physical principles and the current status of several different probe storage devices, including thermo-mechanical probe memory, magnetic probe memory, ferroelectric probe memory, and phase-change probe memory, are reviewed in details, as well as their respective merits and weakness. This paper provides an overview of the emerging probe memories potentially for next generation storage device so as to motivate the exploration of more innovative technologies to push forward the development of the probe storage devices.

  10. Overview of Probe-based Storage Technologies.

    Science.gov (United States)

    Wang, Lei; Yang, Ci Hui; Wen, Jing; Gong, Si Di; Peng, Yuan Xiu

    2016-12-01

    The current world is in the age of big data where the total amount of global digital data is growing up at an incredible rate. This indeed necessitates a drastic enhancement on the capacity of conventional data storage devices that are, however, suffering from their respective physical drawbacks. Under this circumstance, it is essential to aggressively explore and develop alternative promising mass storage devices, leading to the presence of probe-based storage devices. In this paper, the physical principles and the current status of several different probe storage devices, including thermo-mechanical probe memory, magnetic probe memory, ferroelectric probe memory, and phase-change probe memory, are reviewed in details, as well as their respective merits and weakness. This paper provides an overview of the emerging probe memories potentially for next generation storage device so as to motivate the exploration of more innovative technologies to push forward the development of the probe storage devices. PMID:27456500

  11. Gravitational Solar Energy Storage Case Study: Mosul Dam

    OpenAIRE

    A. A. Azooz; W. U. Abid; Ibrahim, S. A.

    2013-01-01

    Scientific, technical and economical feasibility of using water as an effective storage medium of solar energy generated by photovoltaic (PV) method is presented. The idea is based on using PV modules to generate electricity, and using this electricity to re-pump water from the outlet of an already existing hydroelectric power station back to the water reservoir. This technique may provide one way of storing and reuse of solar energy.

  12. Biogeochemical aspects of aquifer thermal energy storage.

    OpenAIRE

    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 reactions. The interplay of these reactions may have a negative influence on the operational performance of ATES-systems. The objective of this thesis was to investigate bacterial clogging processes and the biogeochemical...

  13. Experimental evaluation of thermal energy storage

    Science.gov (United States)

    Asbury, J. G.; Hersh, H. N.

    1980-01-01

    The technical performance of commercially available thermal energy storage (TES) residential heating units under severe weather conditions is discussed. The benefits and costs of TES to the user and utility companies were assessed. The TES issues, research and development needs, and barriers to commercialization were identified. The field tests which determined the performance characteristics for the TES are described and the TES systems, which included both ceramic and hydronic systems, are compared.

  14. Electrochemical supercapacitors: Energy storage beyond batteries

    OpenAIRE

    Shukla, AK; Sampath, S.; K. Vijayamohanan

    2000-01-01

    Recently, a new class of reversible electrochemical energy storage systems have been developed that use: (a) the capacitance associated with charging and discharging of the electrical doublelayer at the electrode–electrolyte interface and are hence called electrical double-layer capacitors (EDLCs), and (b) the pseudocapacitance with electrosorption or surface redox reactions which are referred as pseudocapacitors. While EDLCs with capacities of many tens of farads per gram of the electrode ma...

  15. 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…

  16. 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.

  17. Research for superconducting energy storage patterns and its practical countermeasures

    Science.gov (United States)

    Lin, D. H.; Cui, D. J.; Li, B.; Teng, Y.; Zheng, G. L.; Wang, X. Q.

    2013-10-01

    In this paper, we attempt to introduce briefly the significance, the present status, as well as the working principle of the primary patterns of the superconducting energy storage system, first of all. According to the defect on the lower energy storage density of existed superconducting energy storage device, we proposed some new ideas and strategies about how to improve the energy storage density, in which, a brand-new but a tentative proposal regarding the concept of energy compression was emphasized. This investigation has a certain reference value towards the practical application of the superconducting energy storage.

  18. Research for superconducting energy storage patterns and its practical countermeasures

    International Nuclear Information System (INIS)

    Highlights: • Proposed some new ideas and strategies about how to improve the energy storage density for SMES system. • Increasing the effective current density in the superconducting coils or optimizing the configuration of the SMES coil could improve the energy storage density. • A new conceive of energy compression is also proposed. -- Abstract: In this paper, we attempt to introduce briefly the significance, the present status, as well as the working principle of the primary patterns of the superconducting energy storage system, first of all. According to the defect on the lower energy storage density of existed superconducting energy storage device, we proposed some new ideas and strategies about how to improve the energy storage density, in which, a brand-new but a tentative proposal regarding the concept of energy compression was emphasized. This investigation has a certain reference value towards the practical application of the superconducting energy storage

  19. Research for superconducting energy storage patterns and its practical countermeasures

    Energy Technology Data Exchange (ETDEWEB)

    Lin, D.H., E-mail: lindehua_cn@yahoo.com.cn [College of Physics, Chongqing University, JD Duz (USA)-CQU Institute for Superconductivity, Chongqing 400030 (China); Cui, D.J.; Li, B.; Teng, Y.; Zheng, G.L. [College of Physics, Chongqing University, JD Duz (USA)-CQU Institute for Superconductivity, Chongqing 400030 (China); Wang, X.Q. [College of Physics, Chongqing University, JD Duz (USA)-CQU Institute for Superconductivity, Chongqing 400030 (China); State Key Laboratory of Mechanical Transmission, Chongqing University, Chongqing 400030 (China)

    2013-10-15

    Highlights: • Proposed some new ideas and strategies about how to improve the energy storage density for SMES system. • Increasing the effective current density in the superconducting coils or optimizing the configuration of the SMES coil could improve the energy storage density. • A new conceive of energy compression is also proposed. -- Abstract: In this paper, we attempt to introduce briefly the significance, the present status, as well as the working principle of the primary patterns of the superconducting energy storage system, first of all. According to the defect on the lower energy storage density of existed superconducting energy storage device, we proposed some new ideas and strategies about how to improve the energy storage density, in which, a brand-new but a tentative proposal regarding the concept of energy compression was emphasized. This investigation has a certain reference value towards the practical application of the superconducting energy storage.

  20. Ice slurry based thermal storage in multifunctional buildings

    Science.gov (United States)

    Wang, M. J.; Kusumoto, N.

    Ice slurry based thermal storage plays an important role in reshaping patterns of electricity use for space cooling and heating. It offers inherent advantages in energy efficiency, operating savings, load follow-up and flexible installation over conventional thermal storage technologies. This paper provides discussions on the generation mechanism and performance of ice slurry, as well as the operation principle of the ice slurry based thermal storage system. Details of the system design, control strategy and operation performance are given through a case study on a recent installation in Herbis Osaka, the largest simple building complex in Japan. An evaluation of different installations with ice slurry thermal storage reveals that it is a rewarding technology that provides significant operating savings for the building air-conditioning and improves energy utilization efficiency in modern society.

  1. Techno-economic performance evaluation of direct steam generation solar tower plants with thermal energy storage systems based on high-temperature concrete and encapsulated phase change materials

    Science.gov (United States)

    Guédez, R.; Arnaudo, M.; Topel, M.; Zanino, R.; Hassar, Z.; Laumert, B.

    2016-05-01

    Nowadays, direct steam generation concentrated solar tower plants suffer from the absence of a cost-effective thermal energy storage integration. In this study, the prefeasibility of a combined sensible and latent thermal energy storage configuration has been performed from thermodynamic and economic standpoints as a potential storage option. The main advantage of such concept with respect to only sensible or only latent choices is related to the possibility to minimize the thermal losses during system charge and discharge processes by reducing the temperature and pressure drops occurring all along the heat transfer process. Thermodynamic models, heat transfer models, plant integration and control strategies for both a pressurized tank filled with sphere-encapsulated salts and high temperature concrete storage blocks were developed within KTH in-house tool DYESOPT for power plant performance modeling. Once implemented, cross-validated and integrated the new storage model in an existing DYESOPT power plant layout, a sensitivity analysis with regards of storage, solar field and power block sizes was performed to determine the potential impact of integrating the proposed concept. Even for a storage cost figure of 50 USD/kWh, it was found that the integration of the proposed storage configuration can enhance the performance of the power plants by augmenting its availability and reducing its levelized cost of electricity. As expected, it was also found that the benefits are greater for the cases of smaller power block sizes. Specifically, for a power block of 80 MWe a reduction in levelized electricity costs of 8% was estimated together with an increase in capacity factor by 30%, whereas for a power block of 126 MWe the benefits found were a 1.5% cost reduction and 16% availability increase.

  2. Amineborane Based Chemical Hydrogen Storage - Final Report

    International Nuclear Information System (INIS)

    The development of efficient and safe methods for hydrogen storage is a major hurdle that must be overcome to enable the use of hydrogen as an alternative energy carrier. The objectives of this project in the DOE Center of Excellence in Chemical Hydride Storage were both to develop new methods for on-demand, low temperature hydrogen release from chemical hydrides and to design high-conversion off-board methods for chemical hydride regeneration. Because of their reactive protic (N-H) and hydridic (B-H) hydrogens and high hydrogen contents, amineboranes such as ammonia borane, NH3BH3 (AB), 19.6-wt% H2, and ammonia triborane NH3B3H7 (AT), 17.7-wt% H2, were initially identified by the Center as promising, high-capacity chemical hydrogen storage materials with the potential to store and deliver molecular hydrogen through dehydrogenation and hydrolysis reactions. In collaboration with other Center partners, the Penn project focused both on new methods to induce amineborane H2-release and on new strategies for the regeneration the amineborane spent-fuel materials. The Penn approach to improving amineborane H2-release focused on the use of ionic liquids, base additives and metal catalysts to activate AB dehydrogenation and these studies successfully demonstrated that in ionic liquids the AB induction period that had been observed in the solid-state was eliminated and both the rate and extent of AB H2-release were significantly increased. These results have clearly shown that, while improvements are still necessary, many of these systems have the potential to achieve DOE hydrogen-storage goals. The high extent of their H2-release, the tunability of both their H2 materials weight-percents and release rates, and their product control that is attained by either trapping or suppressing unwanted volatile side products, such as borazine, continue to make AB/ionic-liquid based systems attractive candidates for chemical hydrogen storage applications. These studies also demonstrated

  3. Amineborane Based Chemical Hydrogen Storage - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Sneddon, Larry G.

    2011-04-21

    The development of efficient and safe methods for hydrogen storage is a major hurdle that must be overcome to enable the use of hydrogen as an alternative energy carrier. The objectives of this project in the DOE Center of Excellence in Chemical Hydride Storage were both to develop new methods for on-demand, low temperature hydrogen release from chemical hydrides and to design high-conversion off-board methods for chemical hydride regeneration. Because of their reactive protic (N-H) and hydridic (B-H) hydrogens and high hydrogen contents, amineboranes such as ammonia borane, NH3BH3 (AB), 19.6-wt% H2, and ammonia triborane NH3B3H7 (AT), 17.7-wt% H2, were initially identified by the Center as promising, high-capacity chemical hydrogen storage materials with the potential to store and deliver molecular hydrogen through dehydrogenation and hydrolysis reactions. In collaboration with other Center partners, the Penn project focused both on new methods to induce amineborane H2-release and on new strategies for the regeneration the amineborane spent-fuel materials. The Penn approach to improving amineborane H2-release focused on the use of ionic liquids, base additives and metal catalysts to activate AB dehydrogenation and these studies successfully demonstrated that in ionic liquids the AB induction period that had been observed in the solid-state was eliminated and both the rate and extent of AB H2-release were significantly increased. These results have clearly shown that, while improvements are still necessary, many of these systems have the potential to achieve DOE hydrogen-storage goals. The high extent of their H2­-release, the tunability of both their H2 materials weight-percents and release rates, and their product control that is attained by either trapping or suppressing unwanted volatile side products, such as borazine, continue to make AB/ionic­-liquid based systems attractive candidates for chemical hydrogen storage applications. These studies also

  4. Integration of Wind Turbines with Compressed Air Energy Storage

    Science.gov (United States)

    Arsie, I.; Marano, V.; Rizzo, G.; Moran, M.

    2009-08-01

    Some of the major limitations of renewable energy sources are represented by their low power density and intermittent nature, largely depending upon local site and unpredictable weather conditions. These problems concur to increase the unit costs of wind power, so limiting their diffusion. By coupling storage systems with a wind farm, some of the major limitations of wind power, such as a low power density and an unpredictable nature, can be overcome. After an overview on storage systems, the Compressed Air Energy Storage (CAES) is analyzed, and the state of art on such systems is discussed. A Matlab/Simulink model of a hybrid power plant consisting of a wind farm coupled with CAES is then presented. The model has been successfully validated starting from the operating data of the McIntosh CAES Plant in Alabama. Time-series neural network-based wind speed forecasting are employed to determine the optimal daily operation strategy for the storage system. A detailed economic analysis has been carried out: investment and maintenance costs are estimated based on literature data, while operational costs and revenues are calculated according to energy market prices. As shown in the paper, the knowledge of the expected available energy is a key factor to optimize the management strategies of the proposed hybrid power plant, allowing to obtain environmental and economic benefits.

  5. Simulation of Flywheel Energy Storage System Controls

    Science.gov (United States)

    Truong, Long V.; Wolff, Frederick J.; Dravid, Narayan

    2001-01-01

    This paper presents the progress made in the controller design and operation of a flywheel energy storage system. The switching logic for the converter bridge circuit has been redefined to reduce line current harmonics, even at the highest operating speed of the permanent magnet motor-generator. An electromechanical machine model is utilized to simulate charge and discharge operation of the inertial energy in the flywheel. Controlling the magnitude of phase currents regulates the rate of charge and discharge. The resulting improvements are demonstrated by simulation.

  6. Optimal allocation of energy storage in a co-optimized electricity market: Benefits assessment and deriving indicators for economic storage ventures

    International Nuclear Information System (INIS)

    This paper presents a framework for optimally allocating storage technologies in a power system. This decision support tool helps in quantitatively answering the questions on “where to and how much to install” considering the profits from arbitrage opportunities in a co-optimized electricity market. The developed framework is illustrated on a modified IEEE (Institute of Electrical and Electronics Engineers) 24 bus RTS (Reliability Test System), and the framework finds the optimal allocation solution and the revenues storage earns at each of these locations. Bulk energy storage, CAES (compressed air energy storage) is used as the representative storage technology, and the benefits of optimally allocated storage integration onto the grid are compared with transmission expansion solution. The paper also discusses about system-level indicators to identify candidate locations for economical storage ventures, which are derived based on the optimal storage allocation solution; and applies the market price based storage venture indicators on MISO (Mid-continental Independent System Operator) and PJM (Pennsylvania-New Jersey-Maryland Interconnection) electricity markets. - Highlights: • Storage optimal allocation framework based on high-fidelity storage dispatch model. • Storage with transmission addresses energy and ancillary issues under high renewables. • Bulk storage earns higher revenues from co-optimization (∼10× energy only market). • Grid offers distributed opportunities for investing in a strategic mix of storage. • Storage opportunities depend on cross-arbitrage, as seen from MISO (Mid-continental Independent System Operator) and PJM (Pennsylvania-New Jersey-Maryland Interconnection) markets

  7. Palladium based nanomaterials for enhanced hydrogen spillover and storage

    OpenAIRE

    Suresh K. Konda; Aicheng Chen

    2016-01-01

    Hydrogen storage remains one of the most challenging prerequisites to overcome toward the realization of a hydrogen based economy. The use of hydrogen as an energy carrier for fuel cell applications has been limited by the lack of safe and effective hydrogen storage materials. Palladium has high affinity for hydrogen sorption and has been extensively studied, both in the gas phase and under electrochemical conditions. In this review, recent advancements are highlighted and discussed in regard...

  8. Fuzzy droop control loops adjustment for stored energy balance in distributed energy storage system

    OpenAIRE

    Aldana, Nelson Leonardo Diaz; Wu, Dan; Dragicevic, Tomislav; Vasquez, Juan Carlos; Guerrero, Josep M.

    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 distribut...

  9. Power Control Strategy for Microgrid Based on Hybrid Energy Storage System%基于混合储能的微电网功率控制策略

    Institute of Scientific and Technical Information of China (English)

    吴雨; 潘文霞; 冯蒙霜; 包抒一

    2013-01-01

    微电网中间歇式微电源输出功率较大的不确定和波动,给微电网孤网运行时的电能质量和并网运行时的功率可调度控制带来了巨大的挑战.采用单一的储能系统平滑功率波动,不仅无法很好解决上述两种问题,且不利于延长储能元件的寿命.文中利用超级电容的高功率密度、快速充放和蓄电池适于平抑长周期功率波动的特点,提出了基于超级电容和蓄电池组成的混合储能系统及相应的控制策略,微电网孤网运行时采用超级电容平滑波动频率较高的功率,并网运行时结合蓄电池平抑频率较低的功率,通过两者的共同作用提高了微电网孤网运行的电能质量与并网运行的可调度性,同时避免了蓄电池频繁充放电.在PSCAD/EMTDC中建立微电网仿真模型,验证了所提出的混合储能结构及其控制策略的可行性.%The output fluctuation of intermittent micro-power in mircrogrid will bring great challenge to the control of power quality at the island operation mode and the power schedulability at the grid-connected operation mode. Using one type of energy storage system to smooth the power fluctuation is hard to perfectly solve the above problems but is not good to extend the life of energy storage device. This paper proposes a control strategy based on hybrid energy storage system consisted of super-capacitor and battery, which takes advantage of the battery to smooth long-periodic fluctuation power and the high power density, fast charge and discharge of the super-capacitor. The super-capacitor is used to smooth the high fluctuation power when the microgrid on island operation mode. By combining with the battery, the super-capacitor can be used to smooth the low fluctuation power when the microgrid on grid-connected operation mode. Therefore, the power quality on island operation mode and schedulability of the microgrid on grid-connected operation mode can be improved, and too much

  10. 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.

  11. Energy Storage Systems as a Compliment to Wind Power

    Science.gov (United States)

    Sieling, Jared D.; Niederriter, C. F.; Berg, D. A.

    2006-12-01

    As Gustavus Adolphus College prepares to install two wind turbines on campus, we are faced with the question of what to do with the excess electricity that is generated. Since the College pays a substantial demand charge, it would seem fiscally responsible to store the energy and use it for peak shaving, instead of selling it to the power company at their avoided cost. We analyzed six currently available systems: hydrogen energy storage, flywheels, pumped hydroelectric storage, battery storage, compressed air storage, and superconducting magnetic energy storage, for energy and financial suitability. Potential wind turbine production is compared to consumption to determine the energy deficit or excess, which is fed into a model for each of the storage systems. We will discuss the advantages and disadvantages of each of the storage systems and their suitability for energy storage and peak shaving in this situation.

  12. The energy-saving dispatch based on the coordination between pumped storage hydro and wind energy%基于风蓄协调的节能调度方法

    Institute of Scientific and Technical Information of China (English)

    张鹏; 刘继春; 吕林; 杨柳

    2011-01-01

    为解决节能调度中风能接入造成运行成本增加和可靠性降低的问题,提出了一种基于风蓄协调系统的节能调度方法.通过引入多个整型优化变量与协调周期不平衡量约束,反映抽水蓄能机组发电、抽水、空闲等不同运行状态以及风电机组的出力波动特性,并采用混合整数规划方法求解.算例分析表明,该模型能克服风能的间歇性和波动性缺点,提高系统运行可靠性与风能利用率,降低整体运行成本,能提供抽水蓄能机组适应节能调度需求的新型调度方案,具有显著的经济效益与实用价值.%To solve the problems of operation cost increase and reliability decrease after wind power integration in energy-saving dispatch, this paper proposes an energy saving dispatch method based on coordination between pumped storage hydro and wind energy. Through introducing several integer variables which denote different operation states (generation, pumping and idle) of pumped storage hydro unit, and the imbalance constraint during coordination period which illustrates the volatility characteristic of wind power, this paper establishes the energy-saving dispatch model based on the coordination between pumped storage hydro energy and wind energy and solves the model by using mixed integer programming method. The case study shows that this model can overcome the shortcoming of intermittency and volatility of wind power, enhance the reliability of power system and availability rate of wind power, and decrease the operation cost of whole system. The model can also give the new dispatch schedule of pumped storage hydro unit, which meets the requirement of energy saving and thus has significant economic benefits and practical value.

  13. 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...... the coordinated control of wind power and ESS. Due to the different technical characteristics, such as power and energy density, ESS can play different roles either in generation-side, grid-side or demand side. This thesis focuses on the following two scenarios:• Scenario 1: As a part of wind farm, the ESS plays...... 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...

  14. Models for Energy and Charge Transport, and Storage in Biomolecules

    CERN Document Server

    Mingaleev, S F; Gaididei, Yu B; Johansson, M; Rasmussen, K O; Mingaleev, Serge F.; Christiansen, Peter L.; Gaididei, Yuri B.; Johansson, Magnus; Rasmussen, Kim O.

    1999-01-01

    Two models for energy and charge transport and storage in biomolecules are considered. A model based on the discrete nonlinear Schrodinger equation with long-range dispersive interactions (LRI's) between base pairs of DNA is offered for the description of nonlinear dynamics of the DNA molecule. We show that LRI's are responsible for the existence of an interval of bistability where two stable stationary states, a narrow, pinned state and a broad, mobile state, coexist at each value of the total energy. The possibility of controlled switching between pinned and mobile states is demonstrated. The mechanism could be important for controlling energy storage and transport in DNA molecules. Another model is offered for the description of nonlinear excitations in proteins and other anharmonic biomolecules. We show that in the highly anharmonic systems a bound state of Davydov and Boussinesq solitons can exist.

  15. Models for Energy and Charge Transport and Storage in Biomolecules

    OpenAIRE

    Mingaleev, S. F.; Christiansen, P. L.; Gaididei, Yu. B.; M. Johansson; Rasmussen, K.Ø.

    1999-01-01

    Two models for energy and charge transport and storage in biomolecules are considered. A model based on the discrete nonlinear Schrodinger equation with long-range dispersive interactions (LRI's) between base pairs of DNA is offered for the description of nonlinear dynamics of the DNA molecule. We show that LRI's are responsible for the existence of an interval of bistability where two stable stationary states, a narrow, pinned state and a broad, mobile state, coexist at each value of the tot...

  16. 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.”

  17. U.S. Department of Energy Hydrogen Storage Cost Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Law, Karen; Rosenfeld, Jeffrey; Han, Vickie; Chan, Michael; Chiang, Helena; Leonard, Jon

    2013-03-11

    The overall objective of this project is to conduct cost analyses and estimate costs for on- and off-board hydrogen storage technologies under development by the U.S. Department of Energy (DOE) on a consistent, independent basis. This can help guide DOE and stakeholders toward the most-promising research, development and commercialization pathways for hydrogen-fueled vehicles. A specific focus of the project is to estimate hydrogen storage system cost in high-volume production scenarios relative to the DOE target that was in place when this cost analysis was initiated. This report and its results reflect work conducted by TIAX between 2004 and 2012, including recent refinements and updates. The report provides a system-level evaluation of costs and performance for four broad categories of on-board hydrogen storage: (1) reversible on-board metal hydrides (e.g., magnesium hydride, sodium alanate); (2) regenerable off-board chemical hydrogen storage materials(e.g., hydrolysis of sodium borohydride, ammonia borane); (3) high surface area sorbents (e.g., carbon-based materials); and 4) advanced physical storage (e.g., 700-bar compressed, cryo-compressed and liquid hydrogen). Additionally, the off-board efficiency and processing costs of several hydrogen storage systems were evaluated and reported, including: (1) liquid carrier, (2) sodium borohydride, (3) ammonia borane, and (4) magnesium hydride. TIAX applied a bottom-up costing methodology customized to analyze and quantify the processes used in the manufacture of hydrogen storage systems. This methodology, used in conjunction with ® software and other tools, developed costs for all major tank components, balance-of-tank, tank assembly, and system assembly. Based on this methodology, the figure below shows the projected on-board high-volume factory costs of the various analyzed hydrogen storage systems, as designed. Reductions in the key cost drivers may bring hydrogen storage system costs closer to this DOE target

  18. Community energy storage and distribution SCADA improvements

    International Nuclear Information System (INIS)

    The mission of American Electric Power (AEP) is to sustain the real time balance of energy supply and demand. Approximately 2.5 percent of energy generated in the United States (USA) is stored as pumped hydro, compressed air, or in batteries and other devices. This power point presentation discussed the use of SCADA for improving community energy storage (CES) and distribution systems. CES is a distributed fleet of small energy units connected to the transformers in order to serve houses or small commercial loads. CES is operated as a fleet offering multi-megawatt (MW) multi-hour storage. The benefits of CES include backup power, flicker mitigation, and renewable integration. Benefits to the electricity grid include power factor correct, ancillary services, and load leveling at the substation level. SCADA is being used to determine when emergency load reductions are required or when emergency inspections on fans, oil pumps or other devices are needed. An outline of AEP's monitoring system installation plan was also included. tabs., figs.

  19. 不同时间尺度下基于混合储能调度的微网能量优化%Hybrid Energy Storage Scheduling Based Microgrid Energy Optimization Under Different Time Scales

    Institute of Scientific and Technical Information of China (English)

    刘方; 杨秀; 时珊珊; 张美霞; 邓虹; 郭鹏超

    2014-01-01

    According to different features of energy-based energy storage and power-based energy storage in hybrid energy storage system an economic optimization model of microgrid, which corresponds with actual demand, is established. Based on different time scales the day-ahead and real-time scheduling strategies are proposed. Considering poor prediction accuracy of day-ahead scheduling, using chance constrained programming and taking satisfying the demand on reserve under a certain confidence level as reliability constraint and taking the minimum operation cost as the optimization objective and utilizing the difference of TOU price the optimal coordination of the output of micro energy sources and energy storage systems are performed. In allusion to power fluctuation brought about by such uncertain factors as wind turbine, photovoltaic generation and load, in real-time scheduling the first-order low-pass filtering algorithm is applied to smooth the power fluctuation, and the moving average filtering method is utilized to reasonably allocate the post-filtering fluctuating power among hybrid energy storage systems to make the battery energy storage system taking on more low-frequency power fluctuation and the supercapacitor taking on high-frequency power fluctuation. The real-time scheduling is carried out according to day-ahead plan to monitor operating states of all units in real time and to modify the deviation of day-ahead plan caused by the cumulation of power fluctuation in time.%针对混合储能系统中能量型和功率型储能的不同特点,建立了符合实际需求的微网经济优化模型。根据不同时间尺度提出了日前调度策略和实时调度策略。考虑到日前调度预测精度差的弊端,应用机会约束规划,以一定置信水平下满足备用需求作为可靠性约束,将最小运行成本作为优化目标,利用分时电价差异,优化协调各微源和储能系统出力。针对微网内

  20. Energy storage systems program report for FY1996

    Energy Technology Data Exchange (ETDEWEB)

    Butler, P.C.

    1997-05-01

    Sandia National Laboratories, New Mexico, conducts the Energy Storage Systems Program, which is sponsored by the US Department of Energy`s Office of Utility Technologies. The goal of this program is to assist industry in developing cost-effective energy storage systems as a resource option by 2000. Sandia is responsible for the engineering analyses, contracted development, and testing of energy storage systems for stationary applications. This report details the technical achievements realized during fiscal year 1996.

  1. DTU International Energy Report 2013:Energy storage options for future sustainable energy systems

    OpenAIRE

    2013-01-01

    One of the great challenges in the transition to a non-fossil energy system with a high share of fluctuating renewable energy sources such as solar and wind is to align consumption and production in an economically satisfactory manner. Energy storage could provide the necessary balancing power to make this possible. This energy report addresses energy storage from a broad perspective: It analyses smaller stores that can be used locally in for example heat storage in the individual home or veh...

  2. Test profiles for stationary energy-storage applications

    Science.gov (United States)

    Butler, P. C.; Cole, J. F.; Taylor, P. A.

    Evaluation of battery and other energy-storage technologies for stationary uses is progressing rapidly toward application-specific testing. This testing uses computer-based data acquisition and control equipment, active electronic loads and power supplies, and customized software, to enable sophisticated test regimes which simulate actual use conditions. These simulated-use tests provide more accurate performance and life evaluations than simple constant resistance or current testing regimes. Several organizations are cooperating to develop simulated-use tests for utility-scale storage systems, especially battery energy-storage systems (BESSs). Some of the tests use stepped constant-power charge and discharge regimes to simulate conditions created by electric utility applications such as frequency regulation (FR) and spinning reserve (SR). Other test profiles under development simulate conditions for the energy-storage component of remote-area power supplies (RAPSs) which include renewable and/or fossil-fuelled generators. Various RAPS applications have unique sets of service conditions that require specialized test profiles. Almost all RAPS tests and many tests that represent other stationary applications need, however, to simulate significant time periods that storage devices operate at low-to-medium states-of-charge without full recharge. Consideration of these and similar issues in simulated-use test regimes is necessary to predict effectively the responses of the various types of batteries in specific stationary applications. This paper describes existing and evolving stationary applications for energy-storage technologies and test regimes which are designed to simulate them. The paper also discusses efforts to develop international testing standards.

  3. Thermal energy storage concepts and their feasibility

    OpenAIRE

    Honkonen, Mikko

    2016-01-01

    This Master’s thesis is part of Finnish Academy project Solar Community Concept (SCC), which aims to find scientifically based methodologies and solutions for the major challenges and obstacles in the implementation of a solar community concept in the Finnish environment. Main objective of this Master’s thesis to find the most feasible method for seasonal storage of solar heat under Finnish conditions. Does Finnish ground and environmental conditions enable seasonal storing? And if, what ...

  4. Analysis on Optima l Operation Principle of Hydropower Station during Storing Water Period based on Storage Energy An alyzation%基于蓄能分析的水电站蓄水调度规律研究

    Institute of Scientific and Technical Information of China (English)

    刘红岭; 蔡建章; 蔡华祥

    2014-01-01

    In this paper, from the prospect of storage energy analization, the loss of water quality is represented with the loss of in-flow energy and the additon of water level is represented with the addition of storage energy.With the objective of high efficient utili-zation of inflow energy, a new optimal operation mode of storing water period is proposed.Through the comparison between the loss of inlfow energy and the utilized future storage energy, an optimal storing decision method is proposed based on storage energy utili-zation efficience and power demand.%从水库蓄能分析的角度出发,提出以来流能损失表示可发水量的损失,以增加蓄能表示水头的增加,以来流能的高效利用为目标确定水电站蓄水调度运行策略。通过来流能损失与一定水库蓄能利用率下的动用未来水库蓄能的比较分析,提出以蓄能利用效率和电网用电需求确定月内最佳蓄水方案的决策方法。

  5. A review of pumped energy storage schemes

    International Nuclear Information System (INIS)

    The comparative advantages and costs of pumped water storage, steam accumulators, storage of boiler feedwater , and compressed air storage in caverns are described. Boiler feedwater storage in caverns and pumped water storage are most economical. All systems are costly enough to justify developing reactors with load following capabilities. (E.C.B.)

  6. NV energy electricity storage valuation : a study for the DOE Energy Storage Systems program.

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, James F.; Bhatnagar, Dhruv; Samaan, Nader [Pacific Northwest National Laboratory, Richland, WA; Jin, Chunlian [Pacific Northwest National Laboratory, Richland, WA

    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 (%22BA%22) 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 (%22Pay-for-performance%22). 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.

  7. Energy storage benefits and market analysis handbook : a study for the DOE Energy Storage Systems Program.

    Energy Technology Data Exchange (ETDEWEB)

    Eyer, James M. (Distributed Utility Associates, Livermore, CA); Corey, Garth P.; Iannucci, Joseph J., Jr. (Distributed Utility Associates, Livermore, CA)

    2004-12-01

    This Guide describes a high level, technology-neutral framework for assessing potential benefits from and economic market potential for energy storage used for electric utility-related applications. In the United States use of electricity storage to support and optimize transmission and distribution (T&D) services has been limited due to high storage system cost and by limited experience with storage system design and operation. Recent improvement of energy storage and power electronics technologies, coupled with changes in the electricity marketplace, indicate an era of expanding opportunity for electricity storage as a cost-effective electric resource. Some recent developments (in no particular order) that drive the opportunity include: (1) states adoption of the renewables portfolio standard (RPS), which may increased use of renewable generation with intermittent output, (2) financial risk leading to limited investment in new transmission capacity, coupled with increasing congestion on some transmission lines, (3) regional peaking generation capacity constraints, and (4) increasing emphasis on locational marginal pricing (LMP).

  8. Batteries for energy storage. Examples, strategies, solutions

    International Nuclear Information System (INIS)

    This book presents the variety of battery technologies and describes their mobile and stationary applications and uses. The major social project of the energy transition requires a holistic approach that takes into account especially the issues of energy saving and efficiency in addition to the power generation and distribution from renewable resources. In addition, the book provides an outlook on the further development possibilities of battery technology and battery applications. Improved battery technology is an important factor to help electromobility and stationary applications of batteries as distributed energy storage breakthrough. Not least, the importance and the need for the recycling of batteries and the variety of battery technologies are presented that have the greatest importance in terms of resource conservation and resource security.

  9. Low temperature thermal-energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Segaser, C.S.; Christian, J.E.

    1979-03-01

    This report evaluates currently available techniques and estimated costs of low temperature thermal energy storage (TES) devices applicable to Integrated Community Energy Systems (ICES) installations serving communities ranging in size from approximately 3000 (characterized by an electrical load requirement of 2 MWe) to about 100,000 population (characterized by an electrical load requirement of 100 MWe). Thermal energy in the form of either hotness or coldness can be stored in a variety of media as sensible heat by virtue of a change in temperature of the material, or as latent heat of fusion in which the material changes from the liquid phase to the solid phase at essentially a constant temperature. Both types of material are considered for TES in ICES applications.

  10. Energy conversion & storage program. 1995 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, E.J.

    1996-06-01

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

  11. Joint Optimal Design and Operation of Hybrid Energy Storage Systems

    OpenAIRE

    Ghiassi-Farrokhfal, Yashar; Rosenberg, C; Keshav, Srinivasam; Adjaho, Marie-Benedicte

    2015-01-01

    markdownabstractThe wide range of performance characteristics of storage technologies motivates the use of a hybrid energy storage systems (HESS) that combines the best features of multiple technologies. However, HESS design is complex, in that it involves the choice of storage technologies, the sizing of each storage element, and deciding when to charge and discharge each underlying storage element (the operating strategy.We formulate the problem of jointly optimizing the sizing and the oper...

  12. 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 [eds.

    1979-02-01

    The purpose for this manual is to provide information on the design and installation of thermal energy storage in solar heating 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 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 heating domestic water include safety, single- and dual-tank systems, domestic water heating with air- and liquid-based space heating system, and stand-alone domestic hot water systems. Several appendices present common problems with storage systems and their solutions, heat transfer fluid properties, heat exchanger sizing, and sample specifications for heat exchangers, wooden rock bins, steel tanks, concrete tanks, and fiberglass-reinforced plastic tanks.

  13. Self-Assembled Multifunctional Hybrids: Toward Developing High-Performance Graphene-Based Architectures for Energy Storage Devices

    OpenAIRE

    Islam, Md Monirul; Aboutalebi, Seyed Hamed; Cardillo, Dean; Liu, Hua Kun; Konstantinov, Konstantin; Dou, Shi Xue

    2015-01-01

    The prospect of developing multifunctional flexible three-dimensional (3D) architectures based on integrative chemistry for lightweight, foldable, yet robust, electronic components that can turn the many promises of graphene-based devices into reality is an exciting direction that has yet to be explored. Herein, inspired by nature, we demonstrate that through a simple, yet novel solvophobic self-assembly processing approach, nacre-mimicking, layer-by-layer grown, hybrid composite materials (c...

  14. Flywheel Energy Storage for Automotive Applications

    Directory of Open Access Journals (Sweden)

    Magnus Hedlund

    2015-09-01

    Full Text Available A review of flywheel energy storage technology was made, with a special focus on the progress in automotive applications. We found that there are at least 26 university research groups and 27 companies contributing to flywheel technology development. Flywheels are seen to excel in high-power applications, placing them closer in functionality to supercapacitors than to batteries. Examples of flywheels optimized for vehicular applications were found with a specific power of 5.5 kW/kg and a specific energy of 3.5 Wh/kg. Another flywheel system had 3.15 kW/kg and 6.4 Wh/kg, which can be compared to a state-of-the-art supercapacitor vehicular system with 1.7 kW/kg and 2.3 Wh/kg, respectively. Flywheel energy storage is reaching maturity, with 500 flywheel power buffer systems being deployed for London buses (resulting in fuel savings of over 20%, 400 flywheels in operation for grid frequency regulation and many hundreds more installed for uninterruptible power supply (UPS applications. The industry estimates the mass-production cost of a specific consumer-car flywheel system to be 2000 USD. For regular cars, this system has been shown to save 35% fuel in the U.S. Federal Test Procedure (FTP drive cycle.

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

    Science.gov (United States)

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

    2015-05-20

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

  16. 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

    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...

  17. ECONOMIC ANALYSIS OF USER'S GRID-CONNECTED PV SYSTEM BASED ON ENERGY STORAGE SYSTEM%基于储能系统的用户光伏并网发电系统经济性分析

    Institute of Scientific and Technical Information of China (English)

    刘建涛; 曹雷; 马杰; 张建成

    2012-01-01

    Characteristics and structure of user' s grid-connected PV system based on energy storage system was analyzed, and an efficient energy management strategy was proposed, and the impact of ageing process of the energy storage system ( battery) on economic benefits of users was studied. Economic performance of the energy management of both the user' s grid-connected PV system based on energy storage system and the system without energy storage system was analyzed through specific examples. Finally, considering the downward trend of photovoltaic electricity price, the long-term economic advantage of the system based on energy storage system was demonstrated by analyzing the results of the examples.%分析了基于储能系统的户用光伏并网发电系统的结构特点及工作特性,提出一种高效的能量管理策略,研究储能系统(蓄电池)失效进程对用户经济效益的影响,并通过具体算例对比分析无储能系统的光伏并网发电系统和基于储能系统的光伏并网发电系统的运行经济性,最后,考虑光伏并网电价在未来的下降趋势,论证了基于储能系统的户用光伏并网发电系统的长远经济性优势.

  18. Low-Cost Bio-Based Phase Change Materials as an Energy Storage Medium in Building Envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Kaushik [ORNL; Abhari, Mr. Ramin [Renewable Energy Group, Inc.; Shukla, Dr. Nitin [Fraunhofer USA, Center for Sustainable Energy Systems (CSE), Boston; Kosny, Dr. Jan [Fraunhofer USA, Center for Sustainable Energy Systems (CSE), Boston

    2015-01-01

    A promising approach to increasing the energy efficiency of buildings is the implementation of phase change material (PCM) in building envelope systems. Several studies have reported the energy saving potential of PCM in building envelopes. However, wide application of PCMs in building applications has been inhibited, in part, by their high cost. This article describes a novel paraffin product made of naturally occurring fatty acids/glycerides trapped into high density polyethylene (HDPE) pellets and its performance in a building envelope application, with the ultimate goal of commercializing a low-cost PCM platform. The low-cost PCM pellets were mixed with cellulose insulation, installed in external walls and field-tested under natural weatherization conditions for a period of several months. In addition, several PCM samples and PCM-cellulose samples were prepared under controlled conditions for laboratory-scale testing. The laboratory tests were performed to determine the phase change properties of PCM-enhanced cellulose insulation both at microscopic and macroscopic levels. This article presents the data and analysis from the exterior test wall and the laboratory-scale test data. PCM behavior is influenced by the weather and interior conditions, PCM phase change temperature and PCM distribution within the wall cavity, among other factors. Under optimal conditions, the field data showed up to 20% reduction in weekly heat transfer through an external wall due to the PCM compared to cellulose-only insulation.

  19. Strain Engineering to Modify the Electrochemistry of Energy Storage Electrodes

    Science.gov (United States)

    Muralidharan, Nitin; Carter, Rachel; Oakes, Landon; Cohn, Adam P.; Pint, Cary L.

    2016-06-01

    Strain engineering has been a critical aspect of device design in semiconductor manufacturing for the past decade, but remains relatively unexplored for other applications, such as energy storage. Using mechanical strain as an input parameter to modulate electrochemical potentials of metal oxides opens new opportunities intersecting fields of electrochemistry and mechanics. Here we demonstrate that less than 0.1% strain on a Ni-Ti-O based metal-oxide formed on superelastic shape memory NiTi alloys leads to anodic and cathodic peak potential shifts by up to ~30 mV in an electrochemical cell. Moreover, using the superelastic properties of NiTi to enable strain recovery also recovers the electrochemical potential of the metal oxide, providing mechanistic evidence of strain-modified electrochemistry. These results indicate that mechanical energy can be coupled with electrochemical systems to efficiently design and optimize a new class of strain-modulated energy storage materials.

  20. Thermal energy storage - overview and specific insight into nitrate salts for sensible and latent heat storage.

    Science.gov (United States)

    Pfleger, Nicole; Bauer, Thomas; Martin, Claudia; Eck, Markus; Wörner, Antje

    2015-01-01

    Thermal energy storage (TES) is capable to reduce the demand of conventional energy sources for two reasons: First, they prevent the mismatch between the energy supply and the power demand when generating electricity from renewable energy sources. Second, utilization of waste heat in industrial processes by thermal energy storage reduces the final energy consumption. This review focuses mainly on material aspects of alkali nitrate salts. They include thermal properties, thermal decomposition processes as well as a new method to develop optimized salt systems.

  1. Analysis of radiative and phase-change phenomena with application to space-based thermal energy storage

    Science.gov (United States)

    Lund, Kurt O.

    1991-01-01

    The simplified geometry for the analysis is an infinite, axis symmetric annulus with a specified solar flux at the outer radius. The inner radius is either adiabatic (modeling Flight Experiment conditions), or convective (modeling Solar Dynamic conditions). Liquid LiF either contacts the outer wall (modeling ground based testing), or faces a void gap at the outer wall (modeling possible space based conditions). The analysis is presented in three parts: Part 3 considers and adiabatic inner wall and linearized radiation equations; part 2 adds effects of convection at the inner wall; and part 1 includes the effect of the void gap, as well as previous effects, and develops the radiation model further. The main results are the differences in melting behavior which can occur between ground based 1 g experiments and the microgravity flight experiments. Under 1 gravity, melted PCM will always contact the outer wall having the heat flux source, thus providing conductance from this source to the phase change front. In space based tests where a void gap may likely form during solidification, the situation is reversed; radiation is now the only mode of heat transfer and the majority of melting takes place from the inner wall.

  2. Cost analysis of energy storage systems for electric utility applications

    Energy Technology Data Exchange (ETDEWEB)

    Akhil, A. [Sandia National Lab., Albuquerque, NM (United States); Swaminathan, S.; Sen, R.K. [R.K. Sen & Associates, Inc., Bethesda, MD (United States)

    1997-02-01

    Under the sponsorship of the Department of Energy, Office of Utility Technologies, the Energy Storage System Analysis and Development Department at Sandia National Laboratories (SNL) conducted a cost analysis of energy storage systems for electric utility applications. The scope of the study included the analysis of costs for existing and planned battery, SMES, and flywheel energy storage systems. The analysis also identified the potential for cost reduction of key components.

  3. Limits on the Benefits of Energy Storage for Renewable Integration

    OpenAIRE

    Su, Han-I; Gamal, Abbas El

    2011-01-01

    The high variability of renewable energy resources presents significant challenges to the operation of the electric power grid. Conventional generators can be used to mitigate this variability but are costly to operate and produce carbon emissions. Energy storage provides a more environmentally friendly alternative, but is costly to deploy in large amounts. This paper studies the limits on the benefits of energy storage to renewable energy: How effective is storage at mitigating the adverse e...

  4. Emerging electrochemical energy conversion and storage technologies

    Science.gov (United States)

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

    2014-09-01

    Electrochemical cells and systems play a key role in a wide range of industry sectors. These devices are critical enabling technologies for renewable energy; energy management, conservation and storage; pollution control / monitoring; and greenhouse gas reduction. A large number of electrochemical energy technologies have been developed in the past. These systems continue to be optimized in terms of cost, life time and performance, leading to their continued expansion into existing and emerging market sectors. The more established technologies such as deep-cycle batteries and sensors are being joined by emerging technologies such as fuel cells, large format lithium-ion batteries, electrochemical reactors; ion transport membranes and supercapacitors. This growing demand (multi billion dollars) for electrochemical energy systems along with the increasing maturity of a number of technologies is having a significant effect on the global research and development effort which is increasing in both in size and depth. A number of new technologies, which will have substantial impact on the environment and the way we produce and utilize energy, are under development. This paper presents an overview of several emerging electrochemical energy technologies along with a discussion some of the key technical challenges.

  5. Emerging electrochemical energy conversion and storage technologies.

    Science.gov (United States)

    Badwal, Sukhvinder P S; Giddey, Sarbjit S; Munnings, Christopher; Bhatt, Anand I; Hollenkamp, Anthony F

    2014-01-01

    Electrochemical cells and systems play a key role in a wide range of industry sectors. These devices are critical enabling technologies for renewable energy; energy management, conservation, and storage; pollution control/monitoring; and greenhouse gas reduction. A large number of electrochemical energy technologies have been developed in the past. These systems continue to be optimized in terms of cost, life time, and performance, leading to their continued expansion into existing and emerging market sectors. The more established technologies such as deep-cycle batteries and sensors are being joined by emerging technologies such as fuel cells, large format lithium-ion batteries, electrochemical reactors; ion transport membranes and supercapacitors. This growing demand (multi billion dollars) for electrochemical energy systems along with the increasing maturity of a number of technologies is having a significant effect on the global research and development effort which is increasing in both in size and depth. A number of new technologies, which will have substantial impact on the environment and the way we produce and utilize energy, are under development. This paper presents an overview of several emerging electrochemical energy technologies along with a discussion some of the key technical challenges.

  6. Chance-Constrained Programming Based Day-Ahead Optimal Scheduling of Energy Storage%基于机会约束规划的储能日前优化调度

    Institute of Scientific and Technical Information of China (English)

    赵书强; 刘晨亮; 王明雨; 胡永强

    2013-01-01

    To make the output of the hybrid wind/photovoltaic/energy storage system farthest matched with the scheduled output, the method of one-day ahead optimized control of energy storage equipments is adopted. In view of the randomness of PV generation and wind power generation, a chance-constrained programming based optimal control method of energy storage, in which the constraint of power output of energy storage equipments and the constraint of electric quantity are taken into account and the maximum similarity between the total output curve of hybrid wind/photovoltaic/energy storage system and the given scheduled output curve is taken as the objective function, is proposed and solved by stochastic simulation based particle swarm optimization, thus the charging/discharging power of energy storage equipments corresponding to condition that the two curves are most oncoming is obtained. Analysis on results of calculation example shows that the proposed optimized control strategy of energy storage equipments can make the total output of hybrid wind/photovoltaic/energy storage system farthest tracing the scheduled output curve.%为了最大程度地使风光储联合发电系统的出力与计划出力相匹配,采用提前一天对储能装置进行优化控制的方法。因风光出力具有随机性,提出了基于机会约束规划的储能优化控制方法。该方法考虑了储能装置的功率出力和电量约束条件,以风光储总出力曲线与给定的计划出力曲线的相似度最大为目标函数,使用基于随机模拟的粒子群算法求解,得到两条曲线最接近时对应的储能充放电功率。算例分析结果表明,所提出的储能优化控制策略能够使风光储联合发电系统总出力最大程度地跟踪计划出力曲线。

  7. 基于存储结构重配置的分布式存储系统节能算法%Energy-Efficient Algorithms for Distributed Storage System Based on Data Storage Structure Reconfiguration

    Institute of Scientific and Technical Information of China (English)

    廖彬; 于炯; 孙华; 年梅

    2013-01-01

    As an underlying core infrastructure and important component of cloud computing, distributed storage system is the foundation of all kinds of cloud services or applications. However, with the expanding of system scale and energy consumption factors being ignored by its designers, the problem of high energy consumption is exposed. Because of data availability requirements, we cannot simply use the existing energy-saving technologies to solve the distributed storage system's high energy consumption problem. To ensure all data's availability is the premise of designing energy efficient algorithms for distributed storage system. In this paper, we create a system and data availability model After studying the storage structure and mechanism, the relationship between server's status and data's availability, the method to solve the problem of full covering by constructing a data's availability measurement matrix is proposed. The energy saving model for distributed storage system is defined. The RACK is divided into Active-Zone and Sleep-Zone distinct storage area. According to the different data access frequency and regularity, we calculate the different activity factors for different data which decide how many replicas are stored in Active-Zone. The servers in Sleep Zone are turn to sleep for energy saving while the work load of data center is low. Experimental results show that, the energy-efficient algorithms in this paper adapt the access rule and the availability of all the data in system, improve the energy-efficient of distributed storage system, and the algorithm is more efficient when the system's work load and average activity factor is low.%作为云计算底层核心基础设施,分布式数据存储系统是各种云计算服务的基础,是云计算重要的组成部分.然而随着系统规模的不断扩大以及设计时对能耗因素的忽略使其暴露出高能耗问题.由于存在数据可用性要求,使其并不能简单采用已有节能技术

  8. Improving the Energy Efficiency of Pumped-Storage Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Artyukh, S. F., E-mail: artjuch@mail.ru [Kharkov Polytechnic Institute (Ukraine); Galat, V. V. [JSC “UkrHydroEnergo” (Ukraine); Kuz’min, V. V. [JSC “Interregional Electricity Association ELTA” (Ukraine); Chervonenko, I. I. [Kharkov Polytechnic Institute (Ukraine); Shakaryan, Yu. G.; Sokur, P. V. [JSC “R& D Center at Federal Grid Company of Unified Energy System” (Russian Federation)

    2015-01-15

    Possible ways to improve the energy efficiency of hydroelectric generating sets of pumped-storage power plants (PSPPs) are studied. The Kiev PSPP is used as an example to show how its generating sets can be upgraded. It is concluded based on studies conducted that synchronous motor-generators should be replaced with asynchronized motor-generators. The feasibility of changing over the turbine to variable-speed operation is shown.

  9. 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

    analysis of feasible scenarios associated with the net injected power into the grid by customers. A new concept is defined based on the remaining power curve (RPC) associated with the local generation and consumption, and the uncertainties related to PV output and load consumption are modeled in some RPCs...... 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....

  10. Reliability-oriented energy storage sizing in wind power systems

    DEFF Research Database (Denmark)

    Qin, Zian; Liserre, Marco; Blaabjerg, Frede;

    2014-01-01

    Energy storage can be used to suppress the power fluctuations in wind power systems, and thereby reduce the thermal excursion and improve the reliability. Since the cost of the energy storage in large power application is high, it is crucial to have a better understanding of the relationship...... between the size of the energy storage and the reliability benefit it can generate. Therefore, a reliability-oriented energy storage sizing approach is proposed for the wind power systems, where the power, energy, cost and the control strategy of the energy storage are all taken into account....... With the proposed approach, the computational effort is reduced and the impact of the energy storage system on the reliability of the wind power converter can be quantified....

  11. Development of fuel and energy storage technologies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    Development of fuel cell power plants is intended of high-efficiency power generation using such fuels with less air pollution as natural gas, methanol and coal gas. The closest to commercialization is phosphoric acid fuel cells, and the high in efficiency and rich in fuel diversity is molten carbonate fuel cells. The development is intended to cover a wide scope from solid electrolyte fuel cells to solid polymer electrolyte fuel cells. For new battery power storage systems, development is focused on discrete battery energy storage technologies of fixed type and mobile type (such as electric vehicles). The ceramic gas turbine technology development is purposed for improving thermal efficiency and reducing pollutants. Small-scale gas turbines for cogeneration will also be developed. Development of superconduction power application technologies is intended to serve for efficient and stable power supply by dealing with capacity increase and increase in power distribution distance due to increase in power demand. In the operations to improve the spread and general promotion systems for electric vehicles, load leveling is expected by utilizing and storing nighttime electric power. Descriptions are given also on economical city systems which utilize wide-area energy. 30 figs., 7 tabs.

  12. Global root zone storage capacity from satellite-based evaporation

    Science.gov (United States)

    Wang-Erlandsson, Lan; Bastiaanssen, Wim G. M.; Gao, Hongkai; Jägermeyr, Jonas; Senay, Gabriel B.; van Dijk, Albert I. J. M.; Guerschman, Juan P.; Keys, Patrick W.; Gordon, Line J.; Savenije, Hubert H. G.

    2016-04-01

    This study presents an "Earth observation-based" method for estimating root zone storage capacity - a critical, yet uncertain parameter in hydrological and land surface modelling. By assuming that vegetation optimises its root zone storage capacity to bridge critical dry periods, we were able to use state-of-the-art satellite-based evaporation data computed with independent energy balance equations to derive gridded root zone storage capacity at global scale. This approach does not require soil or vegetation information, is model independent, and is in principle scale independent. In contrast to a traditional look-up table approach, our method captures the variability in root zone storage capacity within land cover types, including in rainforests where direct measurements of root depths otherwise are scarce. Implementing the estimated root zone storage capacity in the global hydrological model STEAM (Simple Terrestrial Evaporation to Atmosphere Model) improved evaporation simulation overall, and in particular during the least evaporating months in sub-humid to humid regions with moderate to high seasonality. Our results suggest that several forest types are able to create a large storage to buffer for severe droughts (with a very long return period), in contrast to, for example, savannahs and woody savannahs (medium length return period), as well as grasslands, shrublands, and croplands (very short return period). The presented method to estimate root zone storage capacity eliminates the need for poor resolution soil and rooting depth data that form a limitation for achieving progress in the global land surface modelling community.

  13. Review on the Distributed Energy Storage Technology in the Application of the Micro Network

    OpenAIRE

    Huang Qiyuan; Wang Zhijie; Zhu Jun; Wang Dongwei; Du Bin

    2015-01-01

    This paper summarized the application process of energy storage technology in the micro-grid, elaborated on the development of energy storage technology concisely, and illustrated the roles of battery energy storage, flywheel energy storage, superconducting magnetic energy storage (SMES), super capacitor energy storage and other energy storage and so on in micro-hybrid. Then it compared the performances of some sorts of the storage method. As characteristics and actual demands of micro-grid w...

  14. Optimal energy management of HEVs with hybrid storage system

    International Nuclear Information System (INIS)

    Highlights: • A battery and ultra-capacitor system for parallel hybrid vehicle is considered. • Optimal management using Pontryagin’s minimum principle is developed. • Battery stress limitation is taken into account by means of RMS current. • Rule based management approaching the optimal control is proposed. • Comparison between rule based and optimal management are proposed using Pareto front. - Abstract: Energy storage systems are a key point in the design and development of electric and hybrid vehicles. In order to reduce the battery size and its current stress, a hybrid storage system, where a battery is coupled with an electrical double-layer capacitor (EDLC) is considered in this paper. The energy management of such a configuration is not obvious and the optimal operation concerning the energy consumption and battery RMS current has to be identified. Most of the past work on the optimal energy management of HEVs only considered one additional power source. In this paper, the control of a hybrid vehicle with a hybrid storage system (HSS), where two additional power sources are used, is presented. Applying the Pontryagin’s minimum principle, an optimal energy management strategy is found and compared to a rule-based parameterized control strategy. Simulation results are shown and discussed. Applied on a small compact car, optimal and ruled-based methods show that gains of fuel consumption and/or a battery RMS current higher than 15% may be obtained. The paper also proves that a well tuned rule-based algorithm presents rather good performances when compared to the optimal strategy and remains relevant for different driving cycles. This rule-based algorithm may easily be implemented in a vehicle prototype or in an HIL test bench

  15. Synthesis of Two-Dimensional Materials for Capacitive Energy Storage.

    Science.gov (United States)

    Mendoza-Sánchez, Beatriz; Gogotsi, Yury

    2016-08-01

    The unique properties and great variety of two-dimensional (2D) nanomaterials make them highly attractive for energy storage applications. Here, an insight into the progress made towards the application of 2D nanomaterials for capacitive energy storage is provided. Synthesis methods, and electrochemical performance of various classes of 2D nanomaterials, particularly based on graphene, transition metal oxides, dichalcogenides, and carbides, are presented. The factors that directly influence capacitive performance are discussed throughout the text and include nanosheet composition, morphology and texture, electrode architecture, and device configuration. Recent progress in the fabrication of 2D-nanomaterials-based microsupercapacitors and flexible and free-standing supercapacitors is presented. The main electrode manufacturing techniques with emphasis on scalability and cost-effectiveness are discussed, and include laser scribing, printing, and roll-to-roll manufacture. Various issues that prevent the use of the full energy-storage potential of 2D nanomaterials and how they have been tackled are discussed, and include nanosheet aggregation and the low electrical conductivity of some 2D nanomaterials. Particularly, the design of hybrid and hierarchical 2D and 3D structures based on 2D nanomaterials is presented. Other challenges and opportunities are discussed and include: control of nanosheets size and thickness, chemical and electrochemical instability, and scale-up of electrode films. PMID:27254831

  16. Using energy storage for strategic advantage in competitive electricity markets

    International Nuclear Information System (INIS)

    Energy storage products are emerging for use in power quality, electric transmission and distribution, and renewable energy applications. Despite this emergence into high-value markets, widespread market penetration will only occur when the value of the services that energy storage products can deliver are clearly delineated. The emergence of competitive electricity markets will more clearly define the flexible benefits of energy storage devices. This paper presents a summary of the ESA's position of the status of energy storage technologies, the market barriers, and steps the ESA is undertaking to reduce these barriers. (author)

  17. Primary frequency regulation with Li-ion battery energy storage system: A case study for Denmark

    DEFF Research Database (Denmark)

    Swierczynski, Maciej Jozef; Stroe, Daniel Ioan; Stan, Ana-Irina;

    2013-01-01

    Meeting ambitious goals of transition to distributed and environmentally-friendly renewable energy generation can be difficult to achieve without energy storage systems due to technical and economical challenges. Moreover, energy storage systems have a high potential of not only smoothing...... and improving the predictability of the intermittent renewables but also of providing the ancillary services in the future energy markets. However, this is currently difficult to achieve due to high prices of the energy storage systems and difficulties with accurate prediction of the energy storage systems...... on the results obtained from accelerated lifetime testing. The developed Li­-ion battery lifetime model is later a base for the analyses of the economic profitability of the investment in the Li-ion battery energy storage system (BESS), which delivers the primary frequency regulation service on the Danish...

  18. The AHA Moment: Assessment of the Redox Stability of Ionic Liquids Based on Aromatic Heterocyclic Anions (AHAs) for Nuclear Separations and Electric Energy Storage.

    Science.gov (United States)

    Shkrob, Ilya A; Marin, Timothy W

    2015-11-19

    Because of their extended conjugated bond network, aromatic compounds generally have higher redox stability than less saturated compounds. We conjectured that ionic liquids (ILs) consisting of aromatic heterocyclic anions (AHAs) may exhibit improved radiation and electrochemical stability. Such properties are important in applications of these ILs as diluents in radionuclide separations and electrolytes in the electric energy storage devices. In this study, we systematically examine the redox chemistry of the AHAs. Three classes of these anions have been studied: (i) simple 5-atom ring AHAs, such as the pyrazolide and triazolides, (ii) AHAs containing an adjacent benzene ring, and (iii) AHAs containing electron-withdrawing groups that were introduced to reduce their basicity and interaction with metal ions. It is shown that fragmentation in the reduced and oxidized states of these AHAs does not generally occur, and the two main products, respectively, are the H atom adduct and the imidyl radical. The latter species occurs either as an N σ-radical or as an N π-radical, depending on the length of the N-N bond, and the state that is stabilized in the solid matrix is frequently different from that having the lowest energy in the gas phase. In some instances, the formation of the sandwich π-stack dimer radical anions has been observed. For trifluoromethylated anions, H adduct formation did not occur; instead, there was facile loss of fluoride from their fluorinated groups. The latter can be problematic in nuclear separations, but beneficial in batteries. Overall, our study suggests that AHA-based ILs are viable candidates for use as radiation-exposed diluents and electrolytes.

  19. Hybrid nano-structure for enhanced energy storage devices

    Science.gov (United States)

    Shuvo, Mohammad Arif Ishtiaque

    The goal of this research is to develop electrode materials using various nano-structure hybrids for improved energy storage devices. Enhancing the performance of energy storage device has been gaining tremendous attention since it holds the key solution to advance renewable energy usage thus reduce the consumption of fossil fuels. The application of energy storage devices such as super-capacitor and Li-ion-battery has seen significant growth; however, it is still limited mainly by charge/discharge rate and energy density. One of the solutions is to use nano-structure materials, which offer higher power at high energy density and improved stability during the charge discharge cycling of ions in and out of the storage electrode material. In this research, carbon-based materials (e.g. porous carbon, graphene) in conjunction with metal oxides such as CeO2 nanoparticles/TiO2 nanowires are synthesized utilizing low temperature hydrothermal method for the fabrication of advanced electrode materials. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), X-ray Photoelectron Spectroscopy (XPS), and Fourier Transformation Infrared Spectroscopy (FTIR) were used for materials characterization. Poentio-galvanostat, battery analyzer, and Electrochemical Impedance Spectroscopy (EIS) were used for evaluating the electrochemical performance. The testing results have shown that a maximum 500% higher specific capacitance could be obtained using porous carbon/CeO2 instead of porous carbon for super-capacitor application and microwave exfoliated graphene oxide/TiO2 nanowire hybrid provides up to 80% increment of specific capacity compared to porous carbon anode for Li-ion-battery application.

  20. Energy Conversion and Storage Requirements for Hybrid Electric Aircraft

    Science.gov (United States)

    Misra, Ajay

    2016-01-01

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

  1. Grid Converters for Stationary Battery Energy Storage Systems

    DEFF Research Database (Denmark)

    Trintis, Ionut

    . Another solution is to use distributed energy storage units, and create virtual power plants. Stationary energy storage is a complementary solution, which can postpone the network expansion and can be optimized for dierent kind of grid services. As an energy storage solution with timing for few seconds...... to hours, rated at MW and MWh, battery energy storage systems are suitable and ecient solutions. Grid connection of the storage system can be done at dierent voltage levels, depending on the location and application scenario. For high power and energy ratings, increase in the battery and converter voltage...... ratings can enhance the overall system eciency. This work is divided in two parts, "Control of DC-AC Grid Converters" and "Medium Voltage Grid Converters for Energy Storage". The rst part starts with a brief review of control strategies applied to grid connected DC-AC converters. A control implementation...

  2. Northeastern Center for Chemical Energy Storage (NECCES)

    Energy Technology Data Exchange (ETDEWEB)

    Whittingham, M. Stanley [Stony Brook Univ., NY (United States)

    2015-07-31

    The chemical reactions that occur in batteries are complex, spanning a wide range of time and length scales from atomic jumps to the entire battery structure. The NECCES team of experimentalists and theorists made use of, and developed new methodologies to determine how model compound electrodes function in real time, as batteries are cycled. The team determined that kinetic control of intercalation reactions (reactions in which the crystalline structure is maintained) can be achieved by control of the materials morphology and explains and allows for the high rates of many intercalation reactions where the fundamental properties might indicate poor behavior in a battery application. The small overvoltage required for kinetic control is technically effective and economically feasible. A wide range of state-of-the-art operando techniques was developed to study materials under realistic battery conditions, which are now available to the scientific community. The team also investigated the key reaction steps in conversion electrodes, where the crystal structure is destroyed on reaction with lithium and rebuilt on lithium removal. These so-called conversion reactions have in principle much higher capacities, but were found to form very reactive discharge products that reduce the overall energy efficiency on cycling. It was found that by mixing either the anion, as in FeOF, or the cation, as in Cu1-yFeyF2, the capacity on cycling could be improved. The fundamental understanding of the reactions occurring in electrode materials gained in this study will allow for the development of much improved battery systems for energy storage. This will benefit the public in longer lived electronics, higher electric vehicle ranges at lower costs, and improved grid storage that also enables renewable energy supplies such as wind and solar.

  3. Cloud-Based Data Storage

    Science.gov (United States)

    Waters, John K.

    2011-01-01

    The vulnerability and inefficiency of backing up data on-site is prompting school districts to switch to more secure, less troublesome cloud-based options. District auditors are pushing for a better way to back up their data than the on-site, tape-based system that had been used for years. About three years ago, Hendrick School District in…

  4. Energy storage management system with distributed wireless sensors

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, Joseph C.; Bandhauer, Todd M.

    2015-12-08

    An energy storage system having a multiple different types of energy storage and conversion devices. Each device is equipped with one or more sensors and RFID tags to communicate sensor information wirelessly to a central electronic management system, which is used to control the operation of each device. Each device can have multiple RFID tags and sensor types. Several energy storage and conversion devices can be combined.

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

    OpenAIRE

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

    2014-01-01

    This review summarizes recent studies on carbon nanotube (CNT) fibers for weavable device of optoelectric conversion and energy storage. The intrinsic properties of individual CNTs make the CNT fibers ideal candidates for optoelectric conversion and energy storage. Many potential applications such as solar cell, supercapacitor, and lithium ion battery have been envisaged. The recent advancement in CNT fibers for optoelectric conversion and energy storage and the current challenge including lo...

  6. Efficiency improvement for wind energy pumped storage systems

    DEFF Research Database (Denmark)

    Forcos, A.; Marinescu, C.; Teodorescu, Remus;

    2011-01-01

    Integrating wind energy into the grid may raise stability problems. Solutions for avoiding these situations are studied and energy storage methods are suitable for balancing the energy between the wind turbine and grid. In this paper, an autonomous wind turbine pumped storage system is presented...

  7. Simulation of diurnal thermal energy storage systems: Preliminary results

    Science.gov (United States)

    Katipamula, S.; Somasundaram, S.; Williams, H. R.

    1994-12-01

    This report describes the results of a simulation of thermal energy storage (TES) integrated with a simple-cycle gas turbine cogeneration system. Integrating TES with cogeneration can serve the electrical and thermal loads independently while firing all fuel in the gas turbine. The detailed engineering and economic feasibility of diurnal TES systems integrated with cogeneration systems has been described in two previous PNL reports. The objective of this study was to lay the ground work for optimization of the TES system designs using a simulation tool called TRNSYS (TRaNsient SYstem Simulation). TRNSYS is a transient simulation program with a sequential-modular structure developed at the Solar Energy Laboratory, University of Wisconsin-Madison. The two TES systems selected for the base-case simulations were: (1) a one-tank storage model to represent the oil/rock TES system; and (2) a two-tank storage model to represent the molten nitrate salt TES system. Results of the study clearly indicate that an engineering optimization of the TES system using TRNSYS is possible. The one-tank stratified oil/rock storage model described here is a good starting point for parametric studies of a TES system. Further developments to the TRNSYS library of available models (economizer, evaporator, gas turbine, etc.) are recommended so that the phase-change processes is accurately treated.

  8. Simulation of diurnal thermal energy storage systems: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Katipamula, S.; Somasundaram, S. [Pacific Northwest Lab., Richland, WA (United States); Williams, H.R. [Univ. of Alaska, Fairbanks, AK (United States). Dept. of Mechanical Engineering

    1994-12-01

    This report describes the results of a simulation of thermal energy storage (TES) integrated with a simple-cycle gas turbine cogeneration system. Integrating TES with cogeneration can serve the electrical and thermal loads independently while firing all fuel in the gas turbine. The detailed engineering and economic feasibility of diurnal TES systems integrated with cogeneration systems has been described in two previous PNL reports. The objective of this study was to lay the ground work for optimization of the TES system designs using a simulation tool called TRNSYS (TRaNsient SYstem Simulation). TRNSYS is a transient simulation program with a sequential-modular structure developed at the Solar Energy Laboratory, University of Wisconsin-Madison. The two TES systems selected for the base-case simulations were: (1) a one-tank storage model to represent the oil/rock TES system, and (2) a two-tank storage model to represent the molten nitrate salt TES system. Results of the study clearly indicate that an engineering optimization of the TES system using TRNSYS is possible. The one-tank stratified oil/rock storage model described here is a good starting point for parametric studies of a TES system. Further developments to the TRNSYS library of available models (economizer, evaporator, gas turbine, etc.) are recommended so that the phase-change processes is accurately treated.

  9. Profitability Analysis of Residential Wind Turbines with Battery Energy Storage

    Science.gov (United States)

    She, Ying; Erdem, Ergin; Shi, Jing

    Residential wind turbines are often accompanied by an energy storage system for the off-the-grid users, instead of the on-the-grid users, to reduce the risk of black-out. In this paper, we argue that residential wind turbines with battery energy storage could actually be beneficial to the on-the-grid users as well in terms of monetary gain from differential pricing for buying electricity from the grid and the ability to sell electricity back to the grid. We develop a mixed-integer linear programming model to maximize the profit of a residential wind turbine system while meeting the daily household electricity consumption. A case study is designed to investigate the effects of differential pricing schemes and sell-back schemes on the economic output of a 2-kW wind turbine with lithium battery storage. Overall, based on the current settings in California, a residential wind turbine with battery storage carries more economical benefits than the wind turbine alone.

  10. Composite materials for thermal energy storage: enhancing performance through microstructures.

    Science.gov (United States)

    Ge, Zhiwei; Ye, Feng; Ding, Yulong

    2014-05-01

    Chemical incompatibility and low thermal conductivity issues of molten-salt-based thermal energy storage materials can be addressed by using microstructured composites. Using a eutectic mixture of lithium and sodium carbonates as molten salt, magnesium oxide as supporting material, and graphite as thermal conductivity enhancer, the microstructural development, chemical compatibility, thermal stability, thermal conductivity, and thermal energy storage performance of composite materials are investigated. The ceramic supporting material is essential for preventing salt leakage and hence provides a solution to the chemical incompatibility issue. The use of graphite gives a significant enhancement on the thermal conductivity of the composite. Analyses suggest that the experimentally observed microstructural development of the composite is associated with the wettability of the salt on the ceramic substrate and that on the thermal conduction enhancer. PMID:24591286

  11. Process control of the EUS battery energy storage system

    Energy Technology Data Exchange (ETDEWEB)

    Harke, R.; Pierschke, T.; Schroeder, M. [EUS GmbH, Gelsenkirchen (Germany)

    1999-07-01

    The process control of the EUS battery energy storage system (BESS) is presented which is used to improve the utilization of regenerative energies. This multifunctional energy storage system includes three different functions: (i) Uninterruptible power supply (UPS); (ii) Improvement of power quality; (iii) Peak load shaving. UPS application has a long tradition and is used whenever a reliable power supply is needed. Additionally, nowadays, there is a growing demand for high quality power under consideration of an increase of system perturbation of electric grids. Peak load shaving means in this case the use of regenerative produced power stored in a battery for high peak load periods. For such a multifunctional application large lead-acid batteries with high power and good charge acceptance, as well as good cycle life are needed. The batteries consist of standard OCSM cells with positive tubular plates and negative copper grids but modified according to the special demand of an multifunctional application. This paper is based on two examples where multifunctional energy storage systems have started operation recently in Germany: one system was installed in combination with a 1 MW solar plant in Herne and another one was installed in combination with a 3,5 MW wind farm in Bocholt. At each of both places a 1,2 MWh (1h-rate) lead acid battery has been installed. (orig.)

  12. Joint Optimal Design and Operation of Hybrid Energy Storage Systems

    NARCIS (Netherlands)

    Y. Ghiassi-Farrokhfal (Yashar); C. Rosenberg; S. Keshav (Srinivasam); M.-B. Adjaho (Marie-Benedicte)

    2015-01-01

    markdownabstractThe wide range of performance characteristics of storage technologies motivates the use of a hybrid energy storage systems (HESS) that combines the best features of multiple technologies. However, HESS design is complex, in that it involves the choice of storage technologies, the siz

  13. Study of the potential of energy storage - Investigation report - Synthesis

    International Nuclear Information System (INIS)

    The objective of this study is to assess, for France and its overseas territories, the potential of energy storage by 2030, and to identify the technological sectors which are the most economically relevant. A global surplus has been calculated, as well as the benefit from additional storage capacities. This benefit has been compared with cost predictions by 2030 for different storage technologies. Economically viable powers and types of energy storages are assessed with respect to different scenarios, and impacts in terms of associated jobs are assessed. The document reports and discusses the surplus assessment for the community, describes the various services provided by energy storage, presents the modelling scenarios and hypotheses, discusses the main results of valorisation for the community, presents the various energy storage technologies (gravity, thermodynamic, electrochemical, electrostatic, inertial, latent thermal, thermo-chemical, and power to gas), presents business models and deployment potential for different applications (mass storage of electricity in France, electricity storage in a non-connected area, decentralised electricity storage as a response to grid congestion, valorisation of an electricity storage, thermal storage on a heat network, cold storage, management of diffuse demand of hot water), and discusses implications regarding employment

  14. Multidimensional materials and device architectures for future hybrid energy storage

    Science.gov (United States)

    Lukatskaya, Maria R.; Dunn, Bruce; Gogotsi, Yury

    2016-09-01

    Electrical energy storage plays a vital role in daily life due to our dependence on numerous portable electronic devices. Moreover, with the continued miniaturization of electronics, integration of wireless devices into our homes and clothes and the widely anticipated `Internet of Things', there are intensive efforts to develop miniature yet powerful electrical energy storage devices. This review addresses the cutting edge of electrical energy storage technology, outlining approaches to overcome current limitations and providing future research directions towards the next generation of electrical energy storage devices whose characteristics represent a true hybridization of batteries and electrochemical capacitors.

  15. Residential Solar-Based Seasonal Thermal Storage Systems in Cold Climates: Building Envelope and Thermal Storage

    Directory of Open Access Journals (Sweden)

    Alexandre Hugo

    2012-10-01

    Full Text Available The reduction of electricity use for heating and domestic hot water in cold climates can be achieved by: (1 reducing the heating loads through the improvement of the thermal performance of house envelopes, and (2 using solar energy through a residential solar-based thermal storage system. First, this paper presents the life cycle energy and cost analysis of a typical one-storey detached house, located in Montreal, Canada. Simulation of annual energy use is performed using the TRNSYS software. Second, several design alternatives with improved thermal resistance for walls, ceiling and windows, increased overall air tightness, and increased window-to-wall ratio of South facing windows are evaluated with respect to the life cycle energy use, life cycle emissions and life cycle cost. The solution that minimizes the energy demand is chosen as a reference house for the study of long-term thermal storage. Third, the computer simulation of a solar heating system with solar thermal collectors and long-term thermal storage capacity is presented. Finally, the life cycle cost and life cycle energy use of the solar combisystem are estimated for flat-plate solar collectors and evacuated tube solar collectors, respectively, for the economic and climatic conditions of this study.

  16. Optimization of Experimental Model Parameter Identification for Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Rosario Morello

    2013-09-01

    Full Text Available The smart grid approach is envisioned to take advantage of all available modern technologies in transforming the current power system to provide benefits to all stakeholders in the fields of efficient energy utilisation and of wide integration of renewable sources. Energy storage systems could help to solve some issues that stem from renewable energy usage in terms of stabilizing the intermittent energy production, power quality and power peak mitigation. With the integration of energy storage systems into the smart grids, their accurate modeling becomes a necessity, in order to gain robust real-time control on the network, in terms of stability and energy supply forecasting. In this framework, this paper proposes a procedure to identify the values of the battery model parameters in order to best fit experimental data and integrate it, along with models of energy sources and electrical loads, in a complete framework which represents a real time smart grid management system. The proposed method is based on a hybrid optimisation technique, which makes combined use of a stochastic and a deterministic algorithm, with low computational burden and can therefore be repeated over time in order to account for parameter variations due to the battery’s age and usage.

  17. Energy Storage/Conservation and Carbon Emissions Reduction Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Bigelow, Erik [Center For Transportation And The Environment, Inc., Atlanta, GA (United States)

    2013-01-01

    The U.S. Department of Energy (DOE) awarded the Center for Transportation and the Environment (CTE) federal assistance for the management of a project to develop and test a prototype flywheel-based energy recovery and storage system in partnership with Test Devices, Inc. (TDI). TDI specializes in the testing of jet engine and power generation turbines, which uses a great deal of electrical power for long periods of time. In fact, in 2007, the company consumed 3,498,500 kW-­hr of electricity in their operations, which is equivalent to the electricity of 328 households. For this project, CTE and TDI developed and tested a prototype flywheel-based energy recovery and storage system. This technology is being developed at TDI’s facilities to capture and reuse the energy necessary for the company’s core process. The new technology and equipment is expected to save approximately 80% of the energy used in the TDI process, reducing total annual consumption of power by approximately 60%, saving approximately two million kilowatt-hours annually. Additionally, the energy recycling system will allow TDI and other end users to lower their peak power demand and reduce associated utility demand charges. The use of flywheels in this application is novel and requires significant development work from TDI. Flywheels combine low maintenance costs with very high cycle life with little to no degradation over time, resulting in lifetimes measured in decades. All of these features make flywheels a very attractive option compared to other forms of energy storage, including batteries. Development and deployment of this energy recycling technology will reduce energy consumption during jet engine and stationary turbine development. By reengineering the current inefficient testing process, TDI will reduce risk and time to market of efficiency upgrades of gas turbines across the entire spectrum of applications. Once in place the results from this program will also help other US industries

  18. Energy Storage in Power System Operation: The Power Nodes Modeling Framework

    DEFF Research Database (Denmark)

    Heussen, Kai; Koch, Stephan; Ulbig, Andreas;

    2010-01-01

    designing operation strategies for power systems based on ubiquitous energy storage, for example to buer non-dispatchable generation, as well as for the evaluation of the operational performance in terms of energy eciency, reliability and cost. After introducing the modeling approach and a categorization of......In this paper, a novel concept for the description of energy storage in power systems with dispatchable and non-dispatchable generators and loads is presented. It is based on a system-perspective consideration of energy storage, generation and consumption. This means that grid-relevant aspects such...

  19. Bandwidth based methodology for designing a hybrid energy storage system for a series hybrid electric vehicle with limited all electric mode

    Science.gov (United States)

    Shahverdi, Masood

    The cost and fuel economy of hybrid electrical vehicles (HEVs) are significantly dependent on the power-train energy storage system (ESS). A series HEV with a minimal all-electric mode (AEM) permits minimizing the size and cost of the ESS. This manuscript, pursuing the minimal size tactic, introduces a bandwidth based methodology for designing an efficient ESS. First, for a mid-size reference vehicle, a parametric study is carried out over various minimal-size ESSs, both hybrid (HESS) and non-hybrid (ESS), for finding the highest fuel economy. The results show that a specific type of high power battery with 4.5 kWh capacity can be selected as the winning candidate to study for further minimization. In a second study, following the twin goals of maximizing Fuel Economy (FE) and improving consumer acceptance, a sports car class Series-HEV (SHEV) was considered as a potential application which requires even more ESS minimization. The challenge with this vehicle is to reduce the ESS size compared to 4.5 kWh, because the available space allocation is only one fourth of the allowed battery size in the mid-size study by volume. Therefore, an advanced bandwidth-based controller is developed that allows a hybridized Subaru BRZ model to be realized with a light ESS. The result allows a SHEV to be realized with 1.13 kWh ESS capacity. In a third study, the objective is to find optimum SHEV designs with minimal AEM assumption which cover the design space between the fuel economies in the mid-size car study and the sports car study. Maximizing FE while minimizing ESS cost is more aligned with customer acceptance in the current state of market. The techniques applied to manage the power flow between energy sources of the power-train significantly affect the results of this optimization. A Pareto Frontier, including ESS cost and FE, for a SHEV with limited AEM, is introduced using an advanced bandwidth-based control strategy teamed up with duty ratio control. This controller

  20. Compressed Air Energy Storage System Control and Performance Assessment Using Energy Harvested Index

    Directory of Open Access Journals (Sweden)

    Hanif SedighNejad

    2014-01-01

    Full Text Available In this paper a new concept for control and performance assessment of compressed air energy storage (CAES systems in a hybrid energy system is introduced. The proposed criterion, based on the concept of energy harvest index (HEI, measures the capability of a storage system to capture renewable energy. The overall efficiency of the CAES system and optimum control and design from the technical and economic point of view is presented. A possible application of this idea is an isolated community with significant wind energy resource. A case study reveals the usefulness of the proposed criterion in design, control and implementation of a small CAES system in a hybrid power system (HPM for an isolated community. Energy harvested index and its effectiveness in increasing the wind penetration rate in the total energy production is discussed.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  2. Distributed energy storage: Time-dependent tree flow design

    Science.gov (United States)

    Bejan, A.; Ziaei, S.; Lorente, S.

    2016-05-01

    This article proposes "distributed energy storage" as a basic design problem of distributing energy storage material on an area. The energy flows by fluid flow from a concentrated source to points (users) distributed equidistantly on the area. The flow is time-dependent. Several scenarios are analyzed: sensible-heat storage, latent-heat storage, exergy storage vs energy storage, and the distribution of a finite supply of heat transfer surface between the source fluid and the distributed storage material. The chief conclusion is that the finite amount of storage material should be distributed proportionally with the distribution of the flow rate of heating agent arriving on the area. The total time needed by the source stream to "invade" the area is cumulative (the sum of the storage times required at each storage site) and depends on the energy distribution paths and the sequence in which the users are served by the source stream. Directions for future designs of distributed storage and retrieval are outlined in the concluding section.

  3. Review of electrical energy storage technologies and systems and of their potential for the UK

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This report presents the findings of a review of current energy storage technologies and their potential application in the UK. Five groups of storage technologies are examined: compressed air energy storage; battery energy storage systems including lead-acid, nickel-cadmium, sodium-sulphur, sodium-nickel and lithium ion batteries; electrochemical flow cell systems, including the vanadium redox battery, the zinc bromide battery and the polysulphide battery; kinetic energy storage systems, ie flywheel storage; and fuel cell/electrolyser systems based on hydrogen. Details are given of the technology, its development status, potential applications and the key developers, manufacturers and suppliers. The opportunities available to UK industry and the potential for systems integration and wealth creation are also discussed.

  4. Seneca Compressed Air Energy Storage (CAES) Project

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2012-11-30

    This report provides a review and an analysis of potential environmental justice areas that could be affected by the New York State Electric & Gas (NYSEG) compress air energy storage (CAES) project and identifies existing environmental burden conditions on the area and evaluates additional burden of any significant adverse environmental impact. The review assesses the socioeconomic and demographic conditions of the area surrounding the proposed CAES facility in Schuyler County, New York. Schuyler County is one of 62 counties in New York. Schuyler County’s 2010 population of 18,343 makes it one of the least populated counties in the State (U.S. Census Bureau, 2010). This report was prepared for WorleyParsons by ERM and describes the study area investigated, methods and criteria used to evaluate this area, and the findings and conclusions from the evaluation.

  5. Battery Energy Storage Technology for power systems-An overview

    DEFF Research Database (Denmark)

    Chandrashekhara, Divya K; Østergaard, Jacob

    2009-01-01

    the reliability and performance of these systems is to integrate energy storage devices into the power system network. Further, in the present deregulated markets these storage devices could also be used to increase the profit margins of wind farm owners and even provide arbitrage. This paper discusses...... the present status of battery energy storage technology and methods of assessing their economic viability and impact on power system operation. Further, a discussion on the role of battery storage systems of electric hybrid vehicles in power system storage technologies had been made. Finally, the paper...

  6. Research on optimal power allocation strategy based on SOC state feedback in hybrid energy storage system%基于 SOC 状态反馈的混合储能功率优化策略

    Institute of Scientific and Technical Information of China (English)

    孙纯军; 倪春花; 窦晓波

    2016-01-01

    文中储能系统功率优化分配以一阶惯性滤波系统为基础,介绍了滤波系数的确定方法,首先提出了基于频谱分析的混合储能系统功率分配方法,根据频谱分析结果,确定波动功率在蓄电池与超级电容之间的分配;在频谱分析的基础上,进一步提出了基于SOC状态反馈的混合储能系统功率优化分配方法,并采用模糊控制,根据储能系统荷电状态SOC的值实时调整系统的滤波时间参数,从而实现超级电容-蓄电池储能系统的长期有效运行。最后,在PSCAD/EMTDC中搭建微电网仿真模型,并设计仿真方案,通过仿真验证所提混合储能系统功率优化分配策略的有效性。%Energy storage system has an important significance for reliable and stable operation of micro-grids.Con-sidering the lack of single form of energy storage, ultra-capacitor-battery hybrid energy storage system is used in this paper.Strategies of power distribution of energy storage system are based on first order inertial filter system, and the method to determine the filter coefficients are introduced.Firstly, a method based on spectrum analysis is proposed to distribute the fluctuated power between the battery and ultra-capacitor.Next, a power distribution strategy of hybrid energy storage system based on SOC feedback is proposed.And fuzzy control method is adopted to adjust system pa-rameters in real time according to the state of charge of the storage system, thus achieving the long term operation of hybrid energy storage system.Finally, the models are built in PSCAD /EMTDC to verify the effectiveness of the pow-er distribution strategies through simulation according to the designed projects.

  7. 钠硫电池储能系统的电价机制研究%Research on Electricity Pricing Mechanism of NaS Battery Based Energy Storage System

    Institute of Scientific and Technical Information of China (English)

    孙波; 廖强强; 陆宇东; 周国定; 陈飞杰; 葛红花

    2014-01-01

    A cost-benefit analysis model of NaS battery based energy storage system was established to study the electricity pricing mechanism during load shifting of power grid. The energy storage pricing strategies under three electricity pricing mechanisms, namely the capacity pricing mechanism, the energy pricing mechanism and the two-part electricity pricing mechanism, were discussed. Research results show that the energy pricing mechanism and the two-part electricity pricing mechanism are more suitable for the NaS battery based energy storage system than the energy pricing mechanism. Along with the reduction of specific energy construction cost for NaS battery based energy storage system from 3 000 RMB/kWh to 1 000 RMB/kWh, the discharge price of NaS battery based energy storage system, which is set by the energy pricing mechanism and the two-part electricity pricing mechanism, could be controlled to about 1 RMB/kWh, thus it may possess the elementary capability to compete with the Shanghai industrial and commercial electricity price in peak periods.%采用成本收益模型研究了钠硫电池储能系统在电网削峰填谷作用中的电价机制。从单一容量电价、单一电度电价、两部制电价3种电价机制讨论了固定投资回报期下的储能电价策略。研究结果表明,对于能量型的钠硫电池储能系统,采用单一容量电价机制来制定储能电价不太合适,而采用单一电度电价和两部制电价机制则更为合适。随着钠硫电池储能系统单位能量建设成本从3000元/kW·h降至1000元/kW·h,采用单一电度电价和两部制电价机制制定的放电电价可控制在1元/kW·h左右,初步具备了与上海工商业高峰时段电度电价竞争的优势。

  8. Research on Electricity Pricing Mechanism of NaS Battery Based Energy Storage System%钠硫电池储能系统的电价机制研究

    Institute of Scientific and Technical Information of China (English)

    孙波; 廖强强; 陆宇东; 周国定; 陈飞杰; 葛红花

    2014-01-01

    A cost-benefit analysis model of NaS battery based energy storage system was established to study the electricity pricing mechanism during load shifting of power grid. The energy storage pricing strategies under three electricity pricing mechanisms, namely the capacity pricing mechanism, the energy pricing mechanism and the two-part electricity pricing mechanism, were discussed. Research results show that the energy pricing mechanism and the two-part electricity pricing mechanism are more suitable for the NaS battery based energy storage system than the energy pricing mechanism. Along with the reduction of specific energy construction cost for NaS battery based energy storage system from 3 000 RMB/kWh to 1 000 RMB/kWh, the discharge price of NaS battery based energy storage system, which is set by the energy pricing mechanism and the two-part electricity pricing mechanism, could be controlled to about 1 RMB/kWh, thus it may possess the elementary capability to compete with the Shanghai industrial and commercial electricity price in peak periods.%采用成本收益模型研究了钠硫电池储能系统在电网削峰填谷作用中的电价机制。从单一容量电价、单一电度电价、两部制电价3种电价机制讨论了固定投资回报期下的储能电价策略。研究结果表明,对于能量型的钠硫电池储能系统,采用单一容量电价机制来制定储能电价不太合适,而采用单一电度电价和两部制电价机制则更为合适。随着钠硫电池储能系统单位能量建设成本从3000元/kW·h降至1000元/kW·h,采用单一电度电价和两部制电价机制制定的放电电价可控制在1元/kW·h左右,初步具备了与上海工商业高峰时段电度电价竞争的优势。

  9. Thermochemical solar energy storage via redox oxides: materials and reactor/heat exchanger concepts

    OpenAIRE

    Tescari, Stefania; Agrafiotis, Christos; Breuer, Stefan; de Oliveira, Lamark; Neises-von Puttkamer, Martina; Roeb, Martin; Sattler, Christian

    2014-01-01

    Thermochemical Storage of solar heat exploits the heat effects of reversible chemical reactions for the storage of solar energy. Among the possible reversible gas-solid chemical reactions, the utilization of a pair of redox reactions of multivalent solid oxides can be directly coupled to CSP plants employing air as the heat transfer fluid bypassing the need for a separate heat exchanger. The present work concerns the development of thermochemical storage systems based on such oxide-based r...

  10. Exergy efficient production, storage and distribution of solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Sandnes, Bjoernar

    2003-07-01

    There are two main themes in this thesis. 1) Exergy efficient utilization of solar energy, where the introduction of alternative technologies such as photovoltaic/thermal collectors and phase change energy storage in a low temperature solar system is investigated. 2) The possibility of storing thermal energy in supercooled liquids is investigated. The introductory chapters introduce the concept of exergy, and focus on the use of solar heat as an inherently low quality source for covering low quality demands associated with space heating and hot water. The different stages of solar energy production, storage, and distribution of heat is discussed, with emphasis on exergy relevant issues. With the low temperature solar heating system as background, the introduction of some additional technologies that are investigated. A section of this thesis presents a study of a small scale PV/T collector as a possible component in a low temperature system. In another section the instrumentation that has been built for studies of full-size PV and thermal systems is described, and the possibility of using the PV unit outputs as parameters for controlling the thermal system operation is briefly discussed. It is suggested that the design of the PV/T unit in terms of whether priority should be given to electricity or heat production should be based on how consumption of high quality auxiliary energy is minimized, and not on adding up the combined exergy which is being produced. Solar combisystems require larger heat storage capacities compared to the more common solar hot water systems. Increased volumetric heat storage capacity can be achieved by latent heat storage systems where thermal energy is stored as heat of fusion in phase change materials (PCMs). A section presents a study where spherically encapsulated PCM is incorporated in a solar heat store. Solar combisystems are often complex, and have a relatively large number of interacting components. Another section describes a

  11. NASSN: a NAS-based storage network

    Institute of Scientific and Technical Information of China (English)

    HAN De-zhi

    2007-01-01

    With the digital information and application requirement on the Internet increasing fleetly nowadays,it is urgent to work out a network storage system with a large capacity, a high availability and scalability. To solve the above-mentioned issues, a NAS-based storage network ( for short NASSN) has been designed. Firstly,the NASSN integrates multi-NAS,iNAS (an iSCSI-based NAS) and enterprise SAN with the help of storage virtualization, which can provide a greater capacity and better scalability. Secondly, the NASSN can provide high availability with the help of server and storage subsystem redundancy technologies. Thirdly, the NASSN simultaneously serves for both the file I/O and the block L/O with the help of an iSCSI module, which has the advantages of NAS and SAN. Finally, the NASSN can provide higher I/O speed by a high network-attached channel which implements the direct data transfer between the storage device and client. In the experiments, the NASSN has ultra-high-throughput for both of the file I/O requests and the block I/O requests.

  12. Thermal energy storage. [by means of chemical reactions

    Science.gov (United States)

    Grodzka, P. G.

    1975-01-01

    The principles involved in thermal energy storage by sensible heat, chemical potential energy, and latent heat of fusion are examined for the purpose of evolving selection criteria for material candidates in the low ( 0 C) and high ( 100 C) temperature ranges. The examination identifies some unresolved theoretical considerations and permits a preliminary formulation of an energy storage theory. A number of candidates in the low and high temperature ranges are presented along with a rating of candidates or potential candidates. A few interesting candidates in the 0 to 100 C region are also included. It is concluded that storage by means of reactions whose reversibility can be controlled either by product removal or by catalytic means appear to offer appreciable advantages over storage with reactions whose reversability cannot be controlled. Among such advantages are listed higher heat storage capacities and more favorable options regarding temperatures of collection, storage, and delivery. Among the disadvantages are lower storage efficiencies.

  13. Analysis of lunar regolith thermal energy storage

    Science.gov (United States)

    Colozza, Anthony J.

    1991-01-01

    The concept of using lunar regolith as a thermal energy storage medium was evaluated. The concept was examined by mathematically modeling the absorption and transfer of heat by the lunar regolith. Regolith thermal and physical properties were established through various sources as functions of temperature. Two cases were considered: a semi-infinite, constant temperature, cylindrical heat source embedded in a continuum of lunar regolith and a spherically shaped molten zone of lunar regolith set with an initial temperature profile. The cylindrical analysis was performed in order to examine the amount of energy which can be stored in the regolith during the day. At night, the cylinder acted as a perfect insulator. This cycling was performed until a steady state situation was reached in the surrounding regolith. It was determined that a cycling steady state occurs after approximately 15 day/night cycles. Results were obtained for cylinders of various diameters. The spherical molten zone analysis was performed to establish the amount of thermal energy, within the regolith, necessary to maintain some molten material throughout a nighttime period. This surrounding temperature profile was modeled after the cycling steady state temperature profile established by the cylindrical analysis. It was determined that a molten sphere diameter of 4.76 m is needed to maintain a core temperature near the low end of the melting temperature range throughout one nighttime period.

  14. Identification of energy storage rate components. Theoretical and experimental approach

    Energy Technology Data Exchange (ETDEWEB)

    Oliferuk, W; Maj, M, E-mail: wolif@ippt.gov.p [Fundamental Technological Research, Polish Academy of Sciences, Pawinskiego 5b, 02-106 Warszawa (Poland)

    2010-07-01

    The subject of the present paper is decomposition of energy storage rate into terms related to different mode of deformation. The stored energy is the change in internal energy due to plastic deformation after specimen unloading. Hence, this energy describes the state of the cold-worked material. Whereas, the ratio of the stored energy increment to the appropriate increment of plastic work is the measure of energy conversion process. This ratio is called the energy storage rate. Experimental results show that the energy storage rate is dependent on plastic strain. This dependence is influenced by different microscopic deformation mechanisms. It has been shown that the energy storage rate can be presented as a sum of particular components. Each of them is related to the separate internal microscopic mechanism. Two of the components are identified. One of them is the storage rate of statistically stored dislocation energy related to uniform deformation. Another one is connected with non-uniform deformation at the grain level. It is the storage rate of the long range stresses energy and geometrically necessary dislocation energy. The maximum of energy storage rate, that appeared at initial stage of plastic deformation is discussed in terms of internal micro-stresses.

  15. Seasonal storage of energy in solar heating

    Science.gov (United States)

    Braun, J. E.; Klein, S. A.; Mitchell, J. W.

    1981-01-01

    This paper focuses on several aspects of seasonal storage for space heating using water as the storage medium. The interrelationships between collector area, storage volume, and system performance are investigated using the transient simulation program TRNSYS. The situations for which seasonal storage is most promising are presented. Particular emphasis is placed upon design of seasonal storage systems. A design method is presented which is applicable for storage capacities ranging from a few days to seasonal storage. This design method, coupled with cost information, should be useful in assessing the economic viability of seasonal storage systems. Also investigated are the importance of the load heat exchanger size, tank insulation, collector slope, and year-to-year weather variations in system design.

  16. Superconducting Magnetic Energy Storage:. Conventional and Trapped Field

    Science.gov (United States)

    Rabinowitz, Mario

    Superconducting magnetic energy storage (SMES) is a most efficient system for energy storage because it stores energy directly in electrical form. The SMES concept is described and analyzed with an examination of its economic viability. The impact of high-temperature supeconductivity on SMES is explored, and a trapped energy storage (TES) innovation that may have beneficial technical and economic ramifications is introduced. In addition to presenting a broad overview, this paper may be of help to those making an evaluation of the potential impact of SMES/TES on the development of new energy sources, and to determine for which energy sources it is most appropriate.

  17. Regenesys utility scale energy storage. Overview report of combined energy storage and renewable generation

    International Nuclear Information System (INIS)

    The first part of the paper briefly discusses the advantages and disadvantages of various forms of renewable energy sources with respect to the United Kingdom. It discusses the intermittent nature of wind and solar power and the less intermittent nature of hydro power and energy from biomass. The need to store energy generated, particularly from the intermittent sources, is discussed with special reference to electric batteries and pumped storage. If the energy cannot be stored and delivered when required, then the commercial viability of the source will be adversely affected - the economics and how this fits with NETA are discussed briefly. The second part of the paper is an overview of some relevant literature discussing (a) how the problems of fluctuating supplies may be managed, (b) an analytical assessment of the contribution from wind farms, (c) how fluctuations in wind power can be smoothed using sodium-sulfur batteries, (d) how small generators can get together and reduce trading costs and imbalance exposure under NETA, (e) the benefits of large-scale energy storage to network management and embedded generation, (f) distribution networks, (g) embedded generation and network management issues and (h) costs and benefits of embedded generation. The work was carried out as part of the DTI New and Renewable Energy Programme managed by Future Energy Solutions

  18. Energy storage - underground pumped storage / energy membrane; Energilager - nedgravet pumpelager / energimembran

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder Pedersen, A. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Hededal, O.; Foged, N. (Danmarks Tekniske Univ., DTU Byg. Institut for Byggeri og Anlaeg, Kgs. Lyngby (Denmark)) (and others)

    2010-06-15

    The project deals with a new idea where water from a nearby reservoir - sea, river or lake - via a pump/motor pressurizes a closed underground membrane, meaning that excessive electrical energy is stored as mechanical energy. Afterwards the stored energy is released by the obtained pressure and the amount of water will impel a turbine/generator. Hereby an underground pressurized pump storage can be established. The advantage by such type of pump storage is, that it can be placed, where there is no natural geological formations - high placed lake or alike. The conclusion and results after the completion of Phase 1 and 2 is that the expected losses in the soil layers where the energy is stored as potential energy will be approx. 100J/m{sub 3}. It is expected that the energy loss in the soil layer on a 50x50 m demo installation (performed in Phase 3) would constitute <0.5% of the total energy stored. An elongation of less the <2% of the LDPE membrane was measured in the experiments. This is a lot less than the 7% elongation that the membrane was exposed to during the testing at Danfoss, and further far below elongation of 500% that the supplier indicates. There were no changes on the membrane after the test. (Author)

  19. Numerical Analysis of Doublet Wells for Cold Energy Storage on Heat Damage Treatment in Deep Mines

    Institute of Scientific and Technical Information of China (English)

    HE Man-chao; ZHANG Yi; GUO Dong-ming; QIAN Zeng-zhen

    2006-01-01

    Deep mining is an inevitable tendency in the development of coal industry. There are many heat damage problems with the increase of mining depth. The technology of using doublet wells, together with Heat Exchange Machine Systems (HEMSs), to store cold energy is a key to solve the heat damage problems in deep mines. Based on the geological conditions, thermodynamic and hydraulic parameters of Jiahe Mine, the isotherms in the period of cold energy storage and refrigeration and the volumes of cold water within different temperature ranges of the cold energy storage well were numerically analyzed. The results show that 1) with the same pumped and injected water volumes, the lower the temperature of injected water is, the larger the volume of cold water in the cold energy storage well is. With the larger volume, the effect of cold energy storage is better. 2) the larger the volumes of pumped and reinjected water are, the larger the volume of cold water from the cold energy storage well is. With the larger volume, the effect of refrigeration is better. And 3) without disturbance, the volume and temperature of cold water in the cold energy storage well can keep unchanged or have only a little change for a long time. Therefore the technology of doublet wells for cold energy storage is feasible and the cold energy storage aquifers can meet the requirement of the technology.

  20. First assessment of continental energy storage in CMIP5 simulations

    Science.gov (United States)

    Cuesta-Valero, Francisco José; García-García, Almudena; Beltrami, Hugo; Smerdon, Jason E.

    2016-05-01

    Although much of the energy gained by the climate system over the last century has been stored in the oceans, continental energy storage remains important to estimate the Earth's energy imbalance and also because crucial positive climate feedback processes such as soil carbon and permafrost stability depend on continental energy storage. Here for the first time, 32 general circulation model simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) are examined to assess their ability to characterize the continental energy storage. Results display a consistently lower magnitude of continental energy storage in CMIP5 simulations than the estimates from geothermal data. A large range in heat storage is present across the model ensemble, which is largely explained by the substantial differences in the bottom boundary depths used in each land surface component.