Techno-economic performance of the solar tower power plants integrating with 650 °C high-temperature molten salt thermal energy storage

Concentrating solar power integrated with thermal energy storage is recognized for its stable electricity generation and low carbon. Conventional molten salts, such as solar salt, are commonly used as thermal storage fluids but typically operate below 565 °C, limiting the performance of CSP. Motivated by recent advancements in high-temperature molten salts, this study investigates their potential applications in CSP technology to enhance CSP efficiency and reduce costs. This study presents a supercritical solar thermal power plant featuring high-temperature molten salt heat storage (200–650 °C) and a novel thermal storage circuit design. A comparative analysis of simulated annual operations and techno-economic evaluations over the plant's lifecycle reveals that the system using high-temperature molten salt improves photoelectric conversion efficiency by 4.1 percentage points and boosts annual power generation by 23.59 %, compared to systems using solar salt. Furthermore, the three-tank heat storage system with a dual-loop configuration enhances system schedulability, increasing peak-period power generation by 4.5 %. The levelized cost of electricity (LCOE) for the new system decreases to 0.0550 $/kWh, reflecting a 20.38 % reduction compared to the solar salt system. This study demonstrates the significant potential of high-temperature molten salt to improve CSP system performance by increasing heat storage temperatures and optimizing system design.