Workshop on Energy Storage

Transcription

1 Bioenergy Group Chemical and Environmental Engineering Department Workshop on Energy Storage 12 November :30-18:00. Sala Juan Larrañeta. ETSI Contact: Web:

2 Workshop on Energy Storage (Seville, 12 November 2018) Organization: Chemical and Environmental Engineering Department, University of Seville Chair: Alberto Gómez-Barea Secretar: Israel Pardo Web: Venue: Sala Larrañeta (planta ático), Escuela Técnica Superior de Ingenieros, Sevilla. Camino de los Descubrimientos S/N. Sevilla, SPAIN (ETSI)

3 AGENDA Monday 12 th November Welcome Alberto Gómez Barea 9:00-9:15 Coordinator of Doctoral Program in Energy, Chemical and Environmental Engineering at University of Seville Keynote 1 Energy Storage for the Grid Using Decarbonized Hydrogen: a 9:15-10:30 work in progress Eric Larson University of Princeton 10:30-11:00 Break Keynote 2 The Ca-Looping process, an ancient technology for new 11:00-12:15 challenges: CO2 capture and energy storage José Manuel Valverde University of Seville Keynote 3 CSP integration in a future sustainable system based on 12:15-13:30 renewable power Luis Crespo Protermosolar 13:30-14:45 Lunch time Keynote 4 Solar receivers development and integration with energy 14:45-16:00 storage system for CST Jesús Gómez-Hernández University Carlos III Madrid Keynote 5 Solar Thermal Energy Storage in solid particles: different 16:00-17:15 technologies and future trends Jose A. Almendros Ibañez University of Castilla-La Mancha 17:15-17:30 Break Keynote 6 Grid integration of distributed renewable energy sources 17:30-18:45 Juan Manuel Mauricio University of Seville 18:45-19:00 Wrap-up and closure Alberto Gómez Barea Coordinator of Doctoral Program in Energy, Chemical and Environmental Engineering at University of Seville

4 Energy Storage: challenges and opportunities Alberto Gómez Barea Chemical and Environmental Engineering Department, University of Sevilla, Spain ( The intermittency of large-scale solar energy supply to the electric grid poses significant technical challenges because of the variability of the primary source. To operate reliably and provide dispatchable power, it requires either energy storage or fuel-based backup systems. Solar photovoltaic (SPV) technologies are promising, particularly with the recent drop in costs. However, SPV does not have an intrinsic storage potential. Grid-scale batteries can be used for storage, but they are still expensive and seasonal storage in locations with significant climate variability would be hugely expensive. In contrast, concentrated solar power (CSP) is an effective way to convert solar energy into electricity, with energystorage capability at the grid-scale. Moreover, besides electricity, concentrated solar radiation can be used to drive endothermic process expanding the application of solar energy to key energy and industrial processes. Spain has been a leader in developing and deploying CSP. It is important for the country to continue developing the technology in order to ensure sustained leadership and wider deployment worldwide. Current SOTA CSP plants use concentrate solar energy in the form of high-temperature heat to generate steam that drive turbines/generator units. Most of the existing plants store some of the energy for later use in the form of heated molten salts, thus providing power under non-solar conditions. Intense research and development is being conducted to develop more cost-effective, efficient and environmental-friendly energy storage systems. This workshop is aimed at reviewing the development of technologies in the area of energy storage, with the focus on technologies providing inherent energy storage like those using concentrated thermal solar energy. Various technological and scientific aspects will be discussed like chemical storage based on hydrogen and calcium looping, the use of new receivers to provide higher temperature as well as the use of heat transfer fluids based on solid particles. Also, challenges arising from the power distribution side will be considered, like those related with the transformation of conventional power system to a more distributed generation, where energy storage will play a significant to satisfy real time power demand variations. Besides technical and scientific challenges, social, economic and political aspects are necessary to be considered, like the Spanish and European policies towards decarbonized system and the impact of power from renewable to the grid, and these will be dealt with also in this WS. This course is part of educational activities organized by the Doctoral Program in Energy, Chemical and Environmental Engineering of University of Seville, providing PhD students and young researchers with the opportunity to discuss and be updated on key technical and scientific topics by reputed experts and professionals on outstanding subjects in the field of energy, process, chemical and environmental engineering.

5 Energy Storage for the Grid Using Decarbonized Hydrogen: a work in progress Eric D. Larson Energy Systems Analysis Group. Andlinger Center for Energy & the Env. Princeton University, USA. elarson@princeton.edu Essentially complete decarbonization of the power sector will be required to realize the carbon-mitigation goals of the Paris Accord. Encouragingly, variable renewable electricity (VRE) generation (solar and wind) has been growing rapidly in many parts of the world as a result of falling technology costs and government incentives and mandates aimed at reducing carbon emissions. Continued increases in VRE penetration will be needed. However, the inherent intermittency and variability of wind and solar energy resources will require balancing sources to ensure reliable and continuous supply of electricity that matches load. The main currently available balancing options are carbon-emitting natural gas fired combustion turbines and combined cycles. Low-carbon options are needed. Costs for battery storage are declining and this might increasingly provide balancing capacity across short time scales (hours). However, for longerduration variability (e.g., a fortnight of weak winds) fast-ramping, dispatchable, low-carbon back-up generating sources are needed. In this study, which is still a work in progress, we are conducting a preliminary assessment of the idea of producing hydrogen from natural gas while capturing the byproduct CO 2 and storing it permanently underground. The H 2 is fired in gas turbines when electricity generation is needed to balance VRE generation. When VRE balancing is not needed, the production of H 2 continues, but it is stored in underground salt caverns for later use. A key motivation for designing this H 2-Gen system in this way is to maximize the annual operating hours of the most capital-intensive component of the system, the H 2 production plant. This talk will provide an overview of the energy, carbon, and economic performance of H 2-Gen systems and describe preliminary techno-economic results for a case study application balancing deep penetrations of wind power on a hypothetical electricity grid modeled on the grid operated by the Electric Reliability Council of Texas (ERCOT), which serves most of the U.S. state of Texas.

6 Understanding the role of storage in electrical systems. The essential role of STE/CSP plants Luis Crespo President of Protermosolar. President of Estela ( Energy transition of electrical systems is becoming an urgent need with the goal of CO2 emission reduction. Cheap non dispatchable technologies like Wind and PV will certainly contribute in this direction but both have clear limits on their penetration levels. Furthermore, PV plants deliver only while the sun is shining. Thus, the pressing big question is whether fossil backup could be avoided, or it will be always needed, particularly after sunset. There are basically two different approached that lead us to a great dilemma: High level of surplus production from cheap technologies plus large investments in storage technologies or balanced use of dispatchable and non-dispatchable generation technologies with a proper fit of the system needs. This presentation takes side for the second choice using Solar thermal Electric (STE/CSP) plants, complementing the dispatch profile of PV after sunset along with other recommendations - as the most rational way to advance toward a carbon free electrical sector at an affordable -even minimum cost. The demonstration is carried out comparing the results from the report of the ad hoc Expert Committee of the former Spanish Government based on least cost expansion models with the inductive approach undertaken by Protermosolar, which projects past real production data of renewable technologies to the 2030 horizon. The Expert Committee kept the whole nuclear and gas combined cycle fleet and was not able to reach the EU renewable levels while the Protermosolar mix was able to fulfil the demand without nuclear and with a reduce GCC fleet. The emissions level were 60% lower with the Protermsoolar mix and the curtailments were 82% lower as well. The cost of the generation by 2030 will be similar in both approaches but again somewhat lower in the Protermosolar one.

7 The Ca-Looping process, an ancient technology for new challenges: CO2 capture and Energy Storage Jose Manuel Valverde Facultad de Física. Universidad de Sevilla, Spain The Calcium-Looping (CaL) process, based on the cyclic calcination/carbonation of CaO, has come into scene in the last years with a high potential to be used in large-scale technologies aimed at mitigating global warming. In the CaL process for CO2 capture, the CO2 loaded flue gas is used to fluidize a bed of CaO particles at temperatures around ~650ºC. The carbonated particles are then circulated into a calciner reactor wherein the CaO solids are regenerated at temperatures near ~950ºC under high CO2 concentration. Calcination at such harsh conditions causes a marked sintering and loss of reactivity of the regenerated CaO. This main drawback could be however compensated from the very low cost of natural CaO precursors such as limestone or dolomite. Another emerging application of the CaL process is Thermochemical Energy Storage (TCES) in Concentrated Solar Power (CSP) plants. Importantly, calcination/carbonation conditions to maximize the global CaL-CSP plant efficiency could differ radically from those used for CO2 capture. Thus, carbonation could be carried out at high temperatures under high CO2 partial pressure whereas the solids could be calcined at relatively low temperatures in the absence of CO2. This presentation highlights the role of calcination/carbonation conditions and material properties on the performance of CaO derived from natural precursors. While conditions in the CaL process for CO2 capture lead to a severe CaO deactivation with the number of cycles, the same material exhibits a high and stable conversion at optimum CaL CSP conditions. Moreover, the type of CaL conditions influences critically the reaction kinetics, which plays a main role on the optimization of relevant operation parameters such as the residence time in the reactors.

8 Solar receivers development and integration with energy storage system for CST Jesús Gómez Hernández Departamento de Ingeniería Térmica y de Fluidos, Universidad Carlos III de Madrid, Madrid (Spain9 jegomez@ing.uc3m.es Concentrating Solar Technology has become an attractive solution to store high amounts of energy in a renewable way. These systems, which are composed by a solar field of heliostats, a receiver and a thermal energy storage system, are the heat source for electricity generation and thermochemical processes. To further improve the development of this technology, it is necessary to reduce its high-costs, which are mainly focused on the solar field and the receiver. Thus, any improvement of the efficiency of current solar receivers or the modification of the solar field layout may reduce the total costs. This talk reviews current designs of solar receivers and solar field layouts and its integration with thermal energy storage systems, highlighting the challenges addressed by the new designs. Furthermore, the relevance of both maximum and minimum temperatures of the heat transfer fluid on the system efficiency will be also considered.

9 Solar Thermal Energy Storage in solid particles: different technologies and future trends José A. Almendros-Ibáñez Dpto. de Mecánica Aplicada e Ingeniería de Proyectos, Albacete, Spain Renewable Energy Research Institute, Section of Solar and Energy Efficiency, Albacete, Spain jose.almendros@uclm.es This review summarizes different solar thermal energy storage techniques from a particle technology perspective, including sensible, latent and thermochemical techniques for low- and high-temperature applications that use particles as the storage medium in the thermal energy storage system. The focus is on applications, experimental results, modeling and future trends. This review describes two different particle technologies used to store thermal energy: packed and fluidized beds. The advantages and disadvantages of both technologies are reviewed throughout different studies found in the literature for various thermal energy storage systems. Packed beds have the main advantage of thermal stratification, which increases the efficiency of solar collectors in low-temperature sensible energy storage systems and augments the exergy content in the bed. Moreover, they have been proven to be suitable as dual-media thermocline storage systems for CSP plants. In contrast, the high mixing rates of fluidized beds makes them suitable for the rapid distribution of concentrated solar energy in particle receiver CSP systems. In addition, their high heat and mass transfer rates, compared with those of packed beds, make them the preferred particle technology for thermochemical energy storage applications. This review also notes that it is important to find new materials with an appropriate size and density that can be properly used in a fluidized bed. Additionally, more specific research efforts are necessary to improve the understanding of the behavior of these materials during the fluidization process and over a high number of charging/discharging cycles.

10 Grid integration of distributed renewable energy sources Juan Manuel Mauricio Departamento de Ingeniería Eléctrica, Universidad de Sevilla, Camino de los Descubrimientos s/n, Seville, Spain Power systems are evolving from conventional generators based on carbon, nuclear and large hydro primary sources to distributed generators based on solar and wind power. While the conventional sources are dispatchable, solar and wind are not. Therefore, to transform conventional power system to distributed generators the use of storage is crucial to satisfy real time power demand variations. In this presentation storage applications from the electrical system point of view will be reviewed. Then a discussion on the storage characteristic will be presented considering not only energy and power but also the required charge/discharge cycles number and depth. Conventional generators are based on large synchronous generators while distributed generators are based on power electronic converters. From the electrical point of view converters have several advantages over synchronous machines like faster response and flexibility. However, they do not have the synchronous machine robustness (i.e. overloading capacity of synchronous machine can be around 10 while in converters it can be 2 or less). A review of converters/storage problems and a discussion about thermal storage with synchronous machines will be presented.