How to size regional electrolysis systems - Simple guidelines for deploying grid-supporting electrolysis in regions with renewable energy generation

Our energy system is facing major challenges in the course of the unavoidable shift from fossil fuels to fluctuating renewable energy sources. Regional hydrogen production by electrolysis, utilizing regional available excess energy, can support the expansion of renewable energy by converting surplus energy into hydrogen and supplying it to the end energy sectors as a secondary energy carrier or process media. We developed a methodology which allows the identification of the regional optimal electrolysis scaling, the achievable Levelized Costs of Hydrogen (LCOH) as well as the annually producible amount of hydrogen for Central European regions, using renewable surplus energy from PV and wind production. The results show that as best case currently LCOH of 4.5 €/kg can be achieved in regions with wind energy and LCOH of 5.6 €/kg in regions with PV energy at 1485 €/kW initial investment costs for the hydrogen production infrastructure. In these cases, regions with wind energy require electrolysis systems with a capacity of 60 % of the wind peak power. Regions with PV energy require a scaling factor of only 45 % of the PV peak power. However, we show that the impact of regional electricity demand and grid expansion has a significant influence on the LCOH and the scaling of the electrolysis. These effects were illustrated in clear heatmaps and serve as a guideline for the dimensioning of grid-supporting electrolysis systems by defining the renewable peak power, the regional electricity demand as well as the existing grid capacity of the region under consideration.