Molten-Salt-Based Thermal Storage for Thermal Power Plant Peaking

This study investigates the integration of a molten salt thermal energy storage (TES) system into a 330 MW coal-fired power unit to enhance its operational flexibility and exergy-based performance. Using EBSILON Professional (version 13) software, several heat storage and heat release schemes were modeled and analyzed to assess their effects on turbine performance, coal consumption rate, heat rate, and exergy losses under various load conditions. The results reveal that coupling TES with conventional thermal units can effectively decouple heat and power generation, enabling deep peak-shaving operation while maintaining system efficiency. The six heat storage schemes and seven heat release schemes considered in this study were selected based on the physical characteristics of the 330 MW reheat-steam cycle and the practical constraints of integrating a molten salt TES system into an existing coal-fired unit. Specifically, the schemes were designed to represent all feasible pathways for redirecting thermal energy within the boiler–turbine system, including steam extraction from different turbine stages, reheater-side interventions, and electric-heating-assisted charging options. These schemes also reflect the operational boundaries of the unit, such as allowable extraction fractions, steam temperature limits, and turbine safety margins. The findings demonstrate that molten salt TES can serve as a feasible and efficient pathway for retrofitting existing coal-fired power units to improve load-following capability, reduce fuel consumption, and support grid flexibility under renewable-dominated energy scenarios.