| Power generation from renewable energy has been rapidly increased in China to settle the problems of power shortage of fossil fuels and global warming.While,the power generation of renewable energy is uncertain and intermittent due to the natural conditions,which leads to the imbalance between power supply and demand and makes the power grid confront challenges of safe operation.As the carrier of energy,energy storage technology can store electric energy during excess power and release electric energy in case of power shortage.Thus,the energy storage system is a key technology to cope with the grid with high penetration of renewable energy.Solid oxide cell stack converts the chemical energy of fuels,e.g.,hydrogen,methane,methanol,ammonia,and syngas to electricity efficiently and can operate in both directions,i.e.,switching between fuel cell mode and electrolysis mode,which can balance the fluctuation of renewable energy and integrate the electricity,transportation and chemical industry.Reversible solid oxide fuel cells-based energy storage system is potential for large-scale energy storage due to its various technical options and applications.The objective of this research is to identify the optimal match of reversible solid oxide fuel cells with application and evaluate the feasibility.Optimal reversible solid oxide fuel cells based energy storage system,represented by the thermodynamic performances,capacity,and operation,is affected by the chemical reaction,heat and mass transfer in stacks as well as the heat and mass integration of the system,and is coupled with the application.Moreover,the fluctuation of market prices and the development of technology make the boundary of energy storage systems complicated.Thus,the optimal energy storage system is insufficient considering a single application scenario.Due to the strong multi-scale correlation between system,application,and boundary,feasible technical options and applications of the reversible solid oxide fuel cell energy storage system is currently unclear.To solve this problem,the decomposition-based method of reversible solid oxide cell conceptual design,application,and boundary are put forward to identify the optimal match of energy storage system and application.At first,the conceptual design of the reversible solid oxide fuel cell energy storage system is carried out to establish a design pool,considering electrochemistry,thermochemistry,heat and mass transfer as well as the multi-heat and mass integration.The design pool includes a variety of technical options and optimal designs of energy storage systems.Then,identification of an optimal energy storage system in an application is carried out via design selection,optimal capacity and operation strategy.Finally,considering the uncertainties in the models proposed,a robust sizing optimization method for reversible solid oxide cell stack based energy storage system under multiple uncertainties is proposed.The decomposition-based method is adopted to evaluate the energy storage system in two applications,onsite energy storage and peak regulation.In onsite energy storage application,reversible solid oxide fuel cells based dual-direction plant for power generation and storage via different chemicals are studied by multi-time system optimization method.Effects of mode switch and chemicals onsite storage on optimal match between energy storage system and application are investigated.Then,the dual-direction plant is further expanded to triple-mode plant for peak regulation,which is able to switch between power generation,power storage,and power neutral.The optimal design of triple-mode plant is the trade-off between power generation efficiency,power storage efficiency and plant capital-cost.The decomposition-based method is adopted to evaluate the influence of biomass supply chain,combined operation of multiple plants on system feasibility.Finally,considering the uncertainties in the conceptual design and application,a robust optimization method for the optimization of energy storage system is proposed.The uncertainties affecting the configuration of the energy storage system are deeply explored,which include the thermodynamic parameters of the solid oxide cell stack,the market prices,and the government subsidy.Uncertainty of input parameters is quantified via uncertainty characterization methods,and then the optimal sizing is obtained under various scenarios considering the uncertainty.A global sensitivity analysis is carried out for the factor prioritization of uncertain parameters,pointing out the influential factors of the coping reversible solid oxide cell stack based energy storage system with renewable power plants.In this paper,a decomposition-based method of conceptual design and application identification of the reversible solid oxide cell stack based energy storage system is proposed.Economic feasibility of dual-direction onsite energy storage plant,triple-mode grid regulating plant is evaluated,with the key influential factor identified,which lays the foundation of the commercialized solid oxide fuel cell. |
