Far off-shore wind energy-based hydrogen production: Technological assessment and market valuation designs

This article provides a techno-economic study on coupled offshore wind farm and green hydrogen production via sea water electrolysis (OWF-H2). Offshore wind energy, wind farms (OWF) and water electrolysis (WE) technologies are described. MHyWind (the tool used to perform simulations and optimisations of such plants) is presented, as well as the models of the main components in the study. Three case studies focus on offshore wind farms, either standalone or connected to the grid via export cables, coupled with a battery and electrolysis systems either offshore or onshore. Exhaustive searches and optimisations performed allowed for rules of thumb to be derived on the sizing of coupled OWF-H2 plants, that minimize costs of hydrogen production (LCoH2, in €/kgH2): Non-connected OWF-H2, coupled to a battery, offers the lowest LCoH2, without the costs of H2 transportation, when compared to cases where the WE is installed onshore and connected to the OWF. Using a simple power distribution heuristic, increasing the number of installed WE allows the system to take advantage of more OWF energy but doesn't improve plant efficiency, whereas a battery always does. Finally, within the scope of this study, it is observed that power ratios of optimized plant architectures (leading to the lowest LCoH2) are between 0.8-0.9 for PWE/POWF and 0.3-0.35 for PBattery/POWF.