Energy storage capacity configuration of wind-hydrogen hybrid systems considering electrolyzer dynamic efficiency and thermal balance

As a critical carrier for accommodating renewable energy, the wind-hydrogen hybrid system relies on optimizing capacity configuration to achieve economical operation. However, most existing studies rely on constant-efficiency electrolyzer models, neglecting the thermal balance mechanism, leading to overly conservative capacity configurations and underestimated costs. To address these limitations, this study proposes a novel capacity configuration framework that synergistically integrates electrolyzer dynamic efficiency, thermal balance, and distributionally robust optimization (DRO). Distinct from traditional approaches, a refined electrolyzer model is established that dynamically characterizes the nonlinear Faraday efficiency as a function of current density. Then, a thermal balance system is introduced to recover waste heat and maintain the equipment's optimal temperature, thereby mitigating efficiency degradation. Finally, a Wasserstein distance-based DRO method is employed to handle wind power uncertainty. Simulation results demonstrate that the proposed joint optimization mechanism significantly reduces the planned electrolyzer capacity by approximately 32.3% and total investment costs by 6%. This work provides a new paradigm for economically efficient wind-hydrogen systems by accurately coupling electrochemical and thermodynamic characteristics.