Optimal configuration of complementary coupled energy supply stations for remote offshore hydrogen refueling and charging

With the implementation of China's “offshore hydrogen island” project and the development of hydrogen and electric ships, the proposal of “renewable energy + energy storage + combined hydrogen production” has opened up new ideas for remote offshore energy supply. However, extending the cruising range of deep-ocean unmanned ships without requiring them to pull into shore remains a critical logistical and economic challenge. To address this gap and move beyond conventional single-energy platforms, a novel wind turbine-driven complementary coupled energy supply station for remote offshore hydrogen refueling and charging is proposed. This system aims to meet the daily electricity demand of 50 electric ships and the hydrogen refueling demand of 1000 kg, introducing a dual-timescale hybrid storage architecture. The energy station incorporates elements of wind energy, electrolyzers, fuel cells, hydrogen storage, and electricity storage. Based on 24-h hourly wind speed and load profiles from four typical seasonal days, which serve as representative operational boundaries and peak stress scenarios to guide year-round capacity optimization, a nested two-layer optimization framework combining Bayesian Optimization with Particle Swarm Optimization is used to obtain the optimal capacity configuration. The system is evaluated based on three proposed indexes: the system cost of power, the system cost of hydrogen, and the system cost of energy. Comparative analysis shows that the energy supply station with a fuel cell performs significantly better. It achieves a system cost of power of 0.1789 $/kWh and a system cost of hydrogen of 4.9873 $/kg, which are 29.62% and 35.28% lower, respectively, than the configuration without a fuel cell. This validates the advantage of the hybrid energy storage system, where batteries manage short-term intra-day fluctuations, and hydrogen storage successfully addresses multi-day to cross-seasonal energy deficits. Sensitivity analysis reveals that the lithium-ion battery is the most influential component regarding overall system costs. Finally, the conditions for flexible operation under varying load shares are derived. Ultimately, this study demonstrates that the proposed multi-energy station is highly cost-efficient, providing a robust, scalable engineering blueprint for the design of future remote offshore green energy infrastructure.