Thermodynamic performance analysis of a coupled system of solar energy and AA-CAES

Abstract Advanced Adiabatic Compressed Air Energy Storage (AA-CAES) is a new large-scale physical energy storage technology that can not only further solve the problem of peak shaving and pressure regulation but also has the advantages of high efficiency, clean zero emissions, integration with renewable energy, and great development space. The article first establishes a thermodynamic model for the compression, heat exchange, expansion, heat storage, and throttle valve of the AA-CAES system, and uses air, nitrogen, and oxygen as storage media to study the impact of non-ideal gas properties on system efficiency, further improving system accuracy. The simulation results show that the system has good performance, with a designed charging and discharging efficiency of 67.7%. In order to further improve efficiency, this paper designs a solar thermal storage and Advanced Adiabatic Compressed Air Energy Storage coupling system (AA-CAES+CSP) and simulates its thermodynamic performance and variable operating conditions. The final system’s electrical-to-electrical conversion efficiency reaches 78.22%.