OPTIMIZATION OF ELECTROLYZER OPERATION IN HYBRID PV-GRID ENERGY SYSTEMS FOR GREEN HYDROGEN PRODUCTION

Green hydrogen is increasingly recognized as one of the key technologies for reducing carbon emissions in sectors where direct electrification remains difficult, such as heavy transport and energy-intensive industries. When hydrogen is produced using photovoltaic (PV) electricity, plant operation becomes strongly dependent on the availability of solar energy. In multi-electrolyzer facilities, operators must continuously decide how many units should run, how the available power should be distributed, and when electricity should be imported from the grid. These operational decisions have a direct impact on hydrogen production, energy efficiency, operating costs, and long-term equipment reliability. This research investigates the operation of the EPC Androgen Marche hydrogen plant in Falconara through a comparative simulation study of three dispatch strategies: Equal Distribution (S1), Start- Stop Dispatch (S2), and Rotation Dispatch (S3). The study is based on a deterministic hourly simulation model developed using PVGIS meteorological data, PEM electrolyzer performance characteristics, and the Italian ARERA electricity tariff structure. The plant configuration includes a 7.8 MWp photovoltaic system, four 1 MW PEM electrolyzers, hydrogen storage, and a medium- voltage grid connection. The performance of each strategy was assessed over an entire year (8,760 operating hours) using five evaluation criteria: annual hydrogen production, specific energy consumption, renewable energy utilization, electricity cost per kilogram of hydrogen, and the distribution of operating hours among the electrolyzer units. These indicators were selected to evaluate both operational efficiency and the long-term impact on equipment utilization. The analysis shows that the Equal Distribution strategy is not suitable for the Falconara plant because low solar availability frequently forces all electrolyzers to shut down simultaneously, reducing hydrogen production while increasing energy consumption. Although the Start-Stop and Rotation strategies achieve almost identical production performance, the Rotation strategy distributes operating hours much more evenly across all four units. This significantly improves asset utilization and reduces long-term replacement costs without requiring any additional investment or hardware modifications.Overall, the findings indicate that Rotation Dispatch provides the most practical and economically sustainable operating strategy for the Falconara plant. Beyond this specific case study, the proposed simulation framework offers a simple and adaptable approach that can support operational decision-making for similar industrial green hydrogen facilities. Keywords: Green hydrogen, PEM electrolyzer, Dispatch strategy, PV-grid hybrid system, Falconara plant, Renewable energy, Hydrogen production.