Performance analysis of Carnot battery pumped thermal electricity storage aided with concentrated solar thermal input

The integration of pumped thermal electricity storage (PTES) with concentrated solar power (CSP) systems offers significant potential to enhance renewable energy consumption, optimize solar energy utilization, and elevate the overall efficiency and performance of PTES systems. Existing research on system integration primarily focuses on CSP plants utilizing molten salt for heat collection and PTES systems employing liquid-based heat storage. Limited studies have been conducted on integrating PTES systems incorporating solid packed beds with CSP plants utilizing alternative heat collection materials. For PTES systems featuring solid packed beds and CSP plants employing solid particle heat collection, this study proposes an innovative CSP-aided PTES system (CSP-PTES) that harnesses solar thermal input from a concentrated heliostat field. A thermodynamic model was developed, and mathematical models of system performance criteria were obtained. The effects of critical design and component parameters on system performance were investigated. Employing the Non-dominated Sorting Genetic Algorithm II (NSGA-II), optimization and the trade-off analysis of round-trip efficiency, energy density and power density were performed. The results demonstrate that there is a corresponding decrease in both energy density and power density with round-trip efficiency. The introduction of solar thermal greatly improves the output energy and power density of the system, with solar efficiency reaching up to 48 %, while the round trip efficiency of the system is slightly reduced due to solar efficiency. The variation in energy and power densities is much larger than the round-trip efficiency, resulting in the optimal points with high energy and power densities, and low round-trip efficiency when the LINMAP decision is applied. However, the round-trip efficiency still managed to be about 58 %.