Optimizing the Generation Portfolio and Energy Management Strategy of a Coal-Dominant Utility through Solar-Green Hydrogen Integration: A System-Level Assessment

Growing demand variability, intermittent renewable energy and strict deviation settlement mechanisms (DSM) put coal-dominant public sector utilities in emerging economies under increasing operational and financial strain. This study assesses the techno-economic potential of combining solar photovoltaics (PV) with green hydrogen as a long-duration flexibility resource and looks into the drawbacks of traditional thermal-based balancing in a large integrated utility system. The study quantifies fuel penalties, DSM exposure and emission impacts resulting from thermal cycling using a realistic utility-scale case representative of eastern India. Next, using assumed but field-realistic operational parameters, a system-level solar-hydrogen configuration is modeled. The findings show that while hydrogen-based storage offers multi-hour to seasonal flexibility not possible with batteries alone, it can significantly reduce DSM penalties, mitigate coal cycling losses and lower system-wide emissions. The results show that green hydrogen is an essential operational asset for coal-heavy grids moving toward high renewable penetration, not just a decarbonization vector.