Design and behaviour estimate of a novel solar and fuel cell complementary driven supercritical-CO2 cycle thermal system

Abstract

Solar-integrated fuel cell systems are widely regarded as an effective means of saving energy and reducing emissions, given their ability to decrease reliance on fossil fuels. However, solar thermal power systems are intermittent, whereas fuel cell waste heat power generation has continuous power output. The paper proposes a novel solar and molten carbonate fuel cell complementary driven supercritical-CO2 cycle system. The performance of multi-energy complementary driven supercritical-CO2 cycle and system operation mode conversion is being investigated. The complementary operation mode ensures the continuous output of the proposed system through the switching of the solar module and the fuel cell module. The result indicates that the fuel cell module operates for 23.5 % of the time in a year, resulting in a reduction of the storage tank volume by 14,723 m3 and a decrease of the fixed heliostat area by 108,237 m2. The efficiency of the supercritical-CO2 cycle individually is 43.1 %, and with the addition of the waste heat utilization subsystem, the cycle efficiency of the proposed system reaches 50.89 %. Furthermore, the levelized cost of electricity for the proposed system is 0.1861$/kWh, and the research results can serve as a reference for the design of complementary energy systems.