Multi-objective optimisation of a power generation system integrating solid oxide fuel cell and recuperated supercritical carbon dioxide cycle

Abstract

This article presents an advanced power generation system that integrates a solid oxide fuel cell (SOFC) module with a recuperated supercritical CO2 (s-CO2) cycle. The waste heat generated by the exhaust of the SOFC module is utilised to drive the s-CO2 cycle, resulting in enhanced energy efficiency. The performance of the system was investigated through thermodynamic and economic analyses and optimised using response surface methodology. The optimisation process focused on two objectives: maximising the energy efficiency of the integrated system and minimising the levelised cost of electricity. The study meticulously analysed the effects of important variables such as current density, fuel utilisation factor, and operating temperature of the fuel cell. The optimisation efforts yielded impressive results, achieving an energy efficiency of 64% and a levelised cost of electricity (LCOE) of 0.18£/kWh. The proposed system surpassed traditional natural gas-fuelled power plants in terms of efficiency and specific emissions. Furthermore, the system's performance was evaluated when operated with green hydrogen fuel, which led to a substantial improvement in efficiency, estimated at 73.37%. However, it was found that the LCOE of the system is relatively higher and approximately 15% higher than the methane-based alternative.