Optimizing Operational Strategies for Coal-Fired Power Plants Integrated with PV and Energy Storage: a Case Study of BESS and TSPP

Indonesia's electricity sector is still dominated by Coal-Fired Power Plants (CFPP) which produce high carbon emissions. To support a 28 renewable share by 2038 and harness Indonesia's solar potential, a Mixed Integer Linear Programming (MILP) daily Unit Commitment (UC) model was developed. Three scenarios were simulated: conventional generation only, integrating PV with Battery Energy Storage System (BESS), and integrating PV with Thermal Storage Power Plant (TSPP). The conventional baseline incurs a total daily cost of 320,931.71 USD, while adding PV and BESS raises cost to 384,237.52 USD, due to high capital outlays and round-trip losses, and adding PV with TSPP lowers cost to 380,218.61 USD, demonstrating its economic advantage despite lower efficiency. BESS handles 262.57 MWh of output PV and produce 236.99 MWh, whereas TSPP with the same output PV, produce 96.41 MWh. However, TSPP can be an alternative solution for energy storage because it offers lower investment cost per capacity and longer service life, yielding a more competitive Levelized Cost Of Energy (LCOE) over the long term.