Proposal and Multi-parameter Optimization of Pumped Thermal Energy Storage System Integrated with a Concentrated Photovoltaic/Thermal Solar System

The pumped thermal energy storage system is a promising technology for the distributed energy system. In this study, a pumped thermal energy storage system with supercritical carbon dioxide as the working fluid integrated with a concentrated photovoltaic/thermal solar system was proposed. A thermodynamic analysis model was developed, and a multi-parameter optimization was conducted. A good temperature match between the solar thermal and the pumped thermal energy storage system is achieved due to the introduction of spectral beam splitting technology to improve the solar energy utilization efficiency and the photothermal outlet temperature. The results show that the power-to-power efficiency and the round-trip efficiency of the optimized system are 56.15% and 61.07%, respectively. Moreover, the system exergy performance was analyzed. Results show that the condenser unit has the largest irreversible loss, which accounts for 52.04% of the total.