Multi-objective optimization of photovoltaic system integrated with hybrid calcium-looping thermochemical energy storage and compressed CO₂ energy storage

Based on the calcium looping (CaL)-thermochemical energy storage (TCES), this paper reasonably integrates the compressed CO₂ energy storage (CCES) using CO₂ from the original system, and simultaneously adopts photovoltaic (PV) drive to construct a PV-TCES-CCES integrated system - an option competitive for large-scale, low-cost, and temporally-steady power generation in the future. However, relevant research remains scarce, especially when considering load demand satisfaction in real scenarios. Therefore, this paper innovatively proposes this system and conducts a targeted investigation. Firstly, the prediction of annual system performance is carried out with the target of user-end demand satisfaction. Then, the effects of PV capacity, energy storage hours and energy storage subsystem nominal power on the system economy and reliability are investigated. Finally, the system configuration is optimized using non-dominated sorting genetic algorithm (NSGA-II) to obtain the Pareto frontier. Results show that the optimal balanced solution of system configuration is 275 MW of PV capacity, 10 h of energy storage hours, and 41 MW of energy storage subsystem nominal power, with the corresponding levelized cost of electricity (LCOE) and loss of load probability (LOLP) are reduced from originally 0.23 USD·kWh−1 and 19.7% to presently 0.22 USD·kWh−1 and 13.5%, respectively.