Green hydrogen production in offshore wind farms: Centralised vs. decentralised

Abstract

Offshore green hydrogen (H2) seems an interesting alternative for decarbonisation. However, a comprehensive assessment of their technical feasibility is essential. To this aim, the present paper uses an integral and dynamic mathematical model of a coupled Floating Offshore Wind Turbine (FOWT) and a Polymer Electrolyte Membrane (PEM) Electrolyser. The numerical framework is used to asses the role of H2 in FOWT farms in two main scenarios: i) centralised with all FOWTs connected to a single electrolyser, and ii) decentralised where each FOWT is connected to its own electrolyser. Results show that establishing a minimum operation load threshold and implementing energy storage solutions are crucial. Additionally, the over-sizing of electrolysis plants merits consideration as both the efficiency peak and the energy-to-H2 ratio peak appear to happen at part-load operation regions. Finally, an adequate load management within the electrolysis plant is expected to be critical for highly varying and intermittent energy sources.