The techno-economic potential of large-scale hydrogen storage in Germany for a climate-neutral energy system

Abstract

The seasonal storage of natural gas is a recognized and reliable technology in the energy industry. Salt caverns are particularly suitable for storing alternative gaseous fuels such as hydrogen. Germany has a great technical potential for expanding its cavern storage capacity, which exceeds the expected demand for hydrogen many times. Regarding the projected long-term decline in natural gas use, the question arises as to whether existing caverns can meet future storage requirements. To this end, a techno-economic model is presented to meet electricity and hydrogen demand in a cost-optimal solution. This analysis focused on the utilization of hydrogen storage in terms of energy throughput and maximum storage capacity. To link the outcome of economic dispatch to the literature, the fundamental assumptions are based on comprehensive capacity expansion models. This study advances the state of the art by evaluating key input parameters of the future energy system. By conducting 192 model runs, the analysis revealed the range of uncertainty in terms of storage use. This indicates a strong dependence of the systemic and economic value of hydrogen storage on boundary conditions such as a consideration of dark doldrums, a flexible hydrogen demand profile, hydrogen import restrictions and a larger electrolyzer capacity. The uncertainty ranged from 0 to 67 TWhH2 for the storage capacity, with an average of 36.6 TWhH2 across all scenarios, and from 0 to 190 TWhH2 for the annual energy throughput. These results are significant for gas storage operators who derive transformation strategies and policymakers evaluating financial funding requirements.