Wind-solar hybrid hydrogen production system and capacity optimization based on power allocation strategy

Through hydrogen production based on wind-solar power generation, variable renewable energy can be converted into high-quality hydrogen. However, the instability of wind and solar energy also leads to the frequent start-up and shutdown of the electrolyzer, as well as the low rate of resource utilization. Herein, the power allocation and cooperative operation strategy and the capacity optimization method for the wind-solar hybrid hydrogen production system were proposed based on the characteristics of wind-solar power generation in combination with the operational performance of alkaline electrolyzer (AEL) and proton exchange membrane electrolyzer (PEMEL) for hydrogen production. The case analysis shows that wind-solar power generation has reduced the impact of resource volatility on the electrolyzer, the average load rates of AEL and PEMEL are 91.08% and 39.90% higher than that of a single wind power scenario. In addition, the hydrogen production capacity is increased by 6.1% by adopting the power allocation strategy, and the start-up/shutdown times of the PEMEL electrolyzer are reduced. Compared with individual AEL and PEMEL hydrogen production system, the hybrid hydrogen production system after capacity optimization has its hydrogen production capacity increased by 7.4%, with the unit hydrogen production cost reaching 35.3 yuan/kg. The research results could provide a reference for the efficient and cooperative operation of wind-solar hybrid hydrogen production system.