Abstract:
Calcium looping (CaL) thermochemical energy storage (TCES) exhibits promising potential for application in concentrated solar power (CSP) plants. However, the CSP-CaL integrating system encounters challenges related to elevated heat loss and diminished power generation efficiency. Herein, for the sake of a more rational heat management and enhanced energy utilization, we propose a cascaded energy storage and utilization strategy. Accordingly, a cascaded TCES system model consisting of Calcium looping and Magnesium looping (MgL)-MgCO3/MgO thermochemical cycle subsystem is developed. The energy analysis and exergy analysis results show that the solar power efficiency and exergy efficiency of the considered system are 41.7% of 44.7%, which are 2.6% and 2.8% higher than the single CaL energy storage CSP system, respectively, demonstrating the superiority of the proposed strategy and system for CSP application. Furthermore, the operation strategy of the system under off-design conditions is proposed by considering the real solar irradiation, and the yearly overall solar power efficiency is 39.2%. The economic analysis of the proposed system indicates that the levelized cost of electricity ranges from 179–156 $/MWh for different plant sizes and is superior in large-scale CSP plants. The cascaded energy storage and utilization strategy of thermochemical cycles with different working temperatures provides better dispatchability to meet the different thermal energy demands.
Lu, Y., Xuan, Y., Teng, L., Liu, J., & Wang, B. (2024). A cascaded thermochemical energy storage system enabling performance enhancement of concentrated solar power plants. Energy, 288, 129749. https://doi.org/10.1016/j.energy.2023.129749
