Abstract:
In concentrated solar thermochemical cycles, CO2 utilization enables both energy storage and release. However, the high energy consumption associated with CO2 compression has limited the overall performance of solar power generation. In this work, an energy storage system coupling thermochemical and electrochemical cycles is proposed. This system constructs a “heat storage − electricity storage − electricity release − heat release” closed-loop path for the multi-functional utilization of CO2, achieving efficient and low-cost green power production. Energy analysis showed that the thermoelectric cycle coupling enabled the thermochemical subsystem to achieve a round-trip efficiency of 37.78 %, which represented a relative increase of 9.54 % compared to the conventional thermochemical system. Furthermore, the peak round-trip efficiency of the electrochemical subsystem is 74.70 %. The hybrid system achieved a maximum round-trip efficiency of 52.28%. Exergy analysis revealed that the thermochemical subsystem achieved an exergy efficiency of 41.55 %. The hybrid system achieved an exergy efficiency of 53.47%, with a relative increase of 28.69 %. Economic analysis showed that the hybrid system achieved the levelized cost of 94.55 $/MWh, representing a reduction of 40.42 % compared to the conventional thermochemical storage system. Therefore, this hybrid system has great potential for the multi-functional utilization of CO2.
Yang Yu, Zhipeng Zhang, Binjian Nie, Nan He, Qicheng Chen, Zhihui Wang, Liang Yao, Constructing a novel closed-loop and efficient pathway for multi-functional CO2 utilization in concentrated solar power systems, Energy Conversion and Management, Volume 353, 2026, 121187, ISSN 0196-8904, https://doi.org/10.1016/j.enconman.2026.12118
