A differential evolution model for optimising the size and cost of electrolysers coupled with offshore wind farms

Green hydrogen is a potential means to reduce CO 2 emissions by replacing fossil fuels in energy systems and other applications. For combined electrolyser – wind farm green hydrogen plants, choosing the appropriate electrolyser capacity is critical in order to minimise hydrogen production costs. This study develops and applies a novel optimisation method using differential evolution combined with a detailed model in order to minimise the levelised cost of hydrogen production from offshore wind energy. Two concepts are considered based on offshore wind farms combined with onshore or offshore electrolysers. In the offshore electrolyser concept, the most suitable electrolyser capacity was found to be 91.41 % of wind farm capacity. In the onshore electrolyser concept, the optimal value was 94.54 %. The differential evolution algorithm was observed to rapidly converge to a solution within six iterations demonstrating its suitability for application in sizing of hybrid wind-hydrogen plants. • Analytical models are developed for two electrolyser–offshore wind farm concepts. • Dynamic electrolyser efficiency for fluctuating power conditions is considered. • The optimal ratio of offshore electrolyser to wind capacity is 91.41 %. • The optimal ratio of onshore electrolyser to wind capacity is 94.54 %. • Sensitivity analysis of the optimal ratio to input data is presented.