This paper proposes integrating high‑temperature thermal energy storage (HTTES) via an additional thermodynamic cycle to improve load flexibility in a 600 MW subcritical coal unit.
An HTTES‑aided additional cycle is coupled to the conventional steam‑water cycle so stored high‑temperature heat (up to 700 °C) can be converted to extra power during discharge while the base unit remains at rated conditions. The initial steam pressure of the additional cycle governs performance, with reported round‑trip efficiency up to 44.18% at 36 MPa/700 °C and additional net power up to about 6.23% during discharge relative to the base case. The concept targets curtailment reduction by consuming surplus variable renewables for charging and broadening minimum‑load flexibility without deep boiler/turbine redesigns.
HTTES‑aided cycles provide a pathway to repurpose coal plants into flexible assets that absorb surplus renewables and deliver dispatchable power, preparing sites for progressive clean repowering while leveraging existing infrastructure.
Source citation: Applied Thermal Engineering (2020), “A novel approach to improving load flexibility of coal‑fired power plant by integrating high temperature thermal energy storage through additional thermodynamic cycle,” Article 115225; DOI: 10.1016/j.applthermaleng.2020.115225.