Optimal operating rules of hybrid power systems considering the integrated electricity and hydrogen markets

Electricity markets have traditionally shaped the operating strategies for hybrid power systems integrating hydropower, wind, and photovoltaic sources. Previous research has established rule-based operating models of hybrid power systems under electricity markets. However, the recent emergence of hydrogen as a complementary energy carrier, which is projected to account for up to 12 % of global final energy consumption by 2050, introduces additional market complexity. Operating rules that explicitly consider the interactions between electricity and hydrogen markets remain underexplored. This study proposes a systematic framework for deriving optimal operating rules for hydro–hydrogen–wind–photovoltaic hybrid power systems within a coupled electricity-hydrogen market. An integrated market model is formulated to represent dynamic supply–demand interactions, followed by a long-term deterministic optimization model to maximize system revenue and reliability. The operating rule parameters are calibrated using functional-form fitting, and the optimal parameters are derived through a parametrization–simulation–optimization method. A case study on China's Ertan hydro–hydrogen–wind–photovoltaic system demonstrates that the proposed rules increase the average annual revenue from 382.75 to 513.36 million USD (+34.12 %), while the assurance rate rises from 89.32 % to 95.83 % (+7.29 %). Reservoir release is identified as the dominant variable, guiding adaptive allocation of electricity between grid supply and hydrogen production. This work advances the operational design of hybrid systems by offering a practical, market-responsive rule framework suited for integrated energy systems under evolving multi-energy market conditions.