A novel efficient and economic integrated energy system based on solid oxide fuel cell with energy storage and carbon dioxide capture

Solid oxide fuel cell-gas turbine/waste heat recovery system based on supercritical carbon dioxide cycle has attracted widespread attention due to the high efficiency and reliability. However, its single function of electricity production cannot meet the complicated demands associated with buildings especially facing peak-valley regulation, carbon emissions and water supply. In this regard, a multi-functional energy system is proposed with the integration of the liquefied natural gas and compressed air energy storage subsystems. Parametric analyses and dual-objective optimization are conducted to evaluate its thermo-economic performance. Results reveal that liquefied natural gas subsystem, with nearly 100% carbon capture, reduces total cost by 1.69 $/h, and improves efficiency by 7.93%; the compressed air energy storage subsystem can further increase efficiency by 10.26% when providing compressed air; the proposed system is able to achieve high round trip efficiency of 83.04%, and such efficiency is as high as 73.06% even considering the trade-off between efficiency and costs. Such an energy network achieves excellent thermo-economic performance and enables great flexibility, making it promising in practical applications.