Thermodynamic and economic analysis of new compressed air energy storage system integrated with water electrolysis and H2-Fueled solid oxide fuel cell

In this paper, a novel compressed air energy storage system is proposed, integrated with a water electrolysis system and an H2-fueled solid oxide fuel cell-gas turbine-steam turbine combined cycle system. In the charging process, the water electrolysis system and the compressed air energy storage system are used to store the elec-tricity; while in the discharging process, the H2-fueled solid oxide fuel cell-gas turbine-steam turbine combined cycle system and the compressed air energy storage system are set to generate electricity, achieving zero carbon emissions in the whole process. The waste heat from the exhaust air and the hot oil of the compressed air energy storage system is recycled by the feedwater of the H2-fueled solid oxide fuel cell-gas turbine-steam turbine combined cycle system, leading to an improvement in the energy efficiency. Based on the simulation using ASPEN Plus and EBSILON Professional, energy, exergy, economic, and sensitivity analyses were applied to evaluate the performance of the proposed system. The results show that the round-trip efficiency, energy storage density, and exergy efficiency of the compressed air energy storage system can reach 68.24%, 4.98 MJ/m3, and 64.28%, respectively, and the overall efficiency of the whole integrated system improves by 1.33%.