Dutch offshore wind farms are primarily located near the coast and connected to the grid, but as offshore wind farms continue to expand and occupy more space, developers are turning to deeper waters. However, installing traditional monopile or jacket structures in these deeper waters can be expensive. One potential solution is the Dogger Bank, a shallow sand bank located 275 km from the Dutch coast, which allows for inexpensive wind turbine installation and high capacity factors. For far offshore locations like the Dogger Bank, electricity transport can be costly, making hydrogen transport via the existing gas infrastructure a more efficient solution. This could enable hydrogen production far offshore and its use in the decarbonisation of hard-to-abate sectors.

This study focuses on the development of a stand-alone offshore hydrogen production system, incorporating battolyser technology, on the Dogger Bank. The battolyser, which combines a Ni-Fe battery and an alkaline electrolyser, is able to store energy and produce hydrogen efficiently and flexibly. However, as the battolyser is not yet commercially available, the proposed systems are analysed for the years 2030 and 2050. The study examines three system configurations: an electrolyser-battolyser, battolyser-only, and electrolyser-battery configuration. For the electrolysers, alkaline and PEM electrolysis is considered. For the battery a vanadium redox flow battery (VRFB).

To ensure autonomous operation, the battolyser serves as a backup power source for supplying
the system’s auxiliary energy demand. This demand is used to determine the system’s sizing, and a MATLAB/Simulink model is developed to calculate the hydrogen production based on future estimates of technical parameters. The hourly wind data from offshore platforms near the Dogger Bank is used as input for the model. To project future capital expenditures (CAPEX) for the model components, a learning curve method is employed, which assumes a specific cost reduction rate with every doubling of cumulative installed capacity.

This study demonstrates the feasibility of an offshore wind-hydrogen system with battolyser
technology, both technically and economically. Battolyser CAPEX are used as an input variable to estimate a range of possible levelized cost of hydrogen (LCOH) values for different systems. The study findings indicate that LCOH values of less than 1.55 C/kg could be achieved by 2030, and by 2050, these values could drop to less than 1.18 C/kg.