Techno-economic analysis of optimal control scenarios for green hydrogen production from real onshore wind farm, case study: Portugal-terceira Island

Power-to-Hydrogen and Hydrogen-to-X energy attract significant researchers’ interest, especially for long-term energy storage from renewable energy sources (RES). Hydrogen is particularly attractive for isolated island systems and offshore wind farms due to its ability to store and transport energy efficiently than conventional fuels. However, its operational performance strongly depends on dispatch strategies and electrolyzer operational constraints, especially Start/Stop cycling. This paper studied control scenarios to identify the suitable power dispatch between the grid, electrolyzer, batteries, and losses in order to adapt hydrogen production according to the technical constraints of the electrolyzer Start/Stop cycles. Three scenarios, with different electrolyzer configurations and battery states of charge, are tested to estimate the optimal power distribution and hydrogen production. Data from three electrolyzers on Terceira Island, are used to identify the optimal control scenario for energy dispatch. Three scenarios are reflected: 1) using only the surplus energy, 2) combining the surplus with minimal power to keep the electrolyzer running, giving priority to the grid, and 3) giving priority to electrolyzer while injecting surplus into the grid. A MATLAB/StateFlow model was developed to simulate these scenarios, measuring the trade-offs between technical feasibility and economic profitability. The results show that the surplus-only strategy leads to frequent Start/Stop cycles, making it technically unsuitable. The grid-priority strategy improves operational stability but is economically limited due to low electrolyzer utilization. while, the electrolyzer-priority strategy achieves the best techno-economic performance, providing higher hydrogen production and improved profitability, although its effectiveness depends on grid’s ability to absorb excess energy. This study addresses the following research question: which dispatch strategy and electrolyzer sizing provide the best trade-off between technical feasibility, Start/Stop reduction, and economic performance for hydrogen production in isolated island grids under real operational conditions? The findings provide practical insight into optimal control strategies for renewable energy integration in such systems.