The role of hydrogen in a greenhouse gas-neutral energy supply system in Germany

Hydrogen is widely considered to play a pivotal role in successfully transforming the German energy system, but the German government's current “National Hydrogen Strategy” does not specify how hydrogen utilization, production, storage or distribution will be implemented. Addressing key uncertainties for the German energy system's path to greenhouse gas-neutrality, this paper examines hydrogen in different scenarios. This analysis aims to support the concretization of the German hydrogen strategy. Applying a European energy supply model with strong interactions between the conversion sector and the hydrogen system, the analysis focuses on the requirements for geological hydrogen storages and their utilization over the course of a year, the positioning of electrolyzers within Germany, and the contributions of hydrogen transport networks to balancing supply and demand. Regarding seasonal hydrogen storages, the results show that hydrogen storage facilities in the range of 42 TWhH₂ to 104 TWhH₂ are beneficial to shift high electricity generation volumes from onshore wind in spring and fall to winter periods with lower renewable supply and increased electricity and heat demands. In 2050, the scenario results show electrolyzer capacities between 41 GWₑₗ and 75 GWₑₗ in Germany. Electrolyzer sites were found to follow the low-cost renewable energy potential and are concentrated on the North Sea and Baltic Sea coasts with their high wind yields. With respect to a hydrogen transport infrastructure, there were two robust findings: One, a domestic German hydrogen transport network connecting electrolytic hydrogen production sites in northern Germany with hydrogen demand hubs in western and southern Germany is economically efficient. Two, connecting Germany to a European hydrogen transport network with interconnection capacities between 18 GWH₂ and 58 GWH₂ is cost-efficient to meet Germany's substantial hydrogen demand.