Optimal Hydrogen Electrolyzer Sizing to Maximize Solar Energy Utilization and Green Hydrogen Production: A New Approach

To achieve zero carbon emissions, green hydrogen produces through water electrolysis using renewable energy has recognized as one of the most sustainable solutions. Green hydrogen has contributed to decreasing carbon emissions by providing a clean alternative to fossil fuels in a variety of industries applications including power generation and transportation. However, determining the optimal sizing of electrolyzers remains a significant challenge, particularly when aiming to maximize the utilization of available renewable energy resources (RES) and minimizing energy curtailment. This study proposes an optimization approach using a mixed-integer linear programming (MILP) model to determine the optimal number and sizes of electrolyzers in a PV-powered green hydrogen production facility. The proposed method determines the optimal sizing of discrete electrolyzer units based on the on/off switching strategy to maximize solar energy utilization while minimizing power curtailment. Simulation results demonstrate that optimizing the finite number of electrolyzer units improves system performance significantly, leading to increase hydrogen production progressively and solar utilization. A comparative analysis of different cases reveals that increasing the finite number of optimal electrolyzer units improves hydrogen storage production until reaches a saturation point beyond where additional discrete units offer negligible benefits. The results demonstrate that optimal electrolyzers sizing significantly improves power utilization to 99.4%. These findings provide valuable insight for a new method for sizing electrolyzers in PV-powered green hydrogen production facilities.