Refined Evaluation of Underground Hydrogen Storage Capacity of Triassic Sandstones in the North German Basin

Storage of hydrogen will be a key aspect of a prospective future hydrogen economy, with the subsurface being the primary opportunity for large-volume storage. Therefore, it is essential to infer the storage capacity of feasible geological formations. This study combines geological resource assessment with numerical reservoir simulations to refine the underground hydrogen storage capacity of saline aquifers in the North German basin. We identified 341 structural traps in this region, with 289 fulfilling basic requirements for potential storage sites. 176 of these are located in the Bunter Sandstone and 113 in the Exter Formation (Rhätkeuper). We assess their combined potential storage capacity statistically with a Monte-Carlo approach following previous gas-in-place estimates. Dynamic reservoir simulations support this approach by defining ranges on input parameters, like the storage efficiency factor. We find that the identified traps, which lie between 1 km and 3 km depth, have a storage efficiency factor of 0.01 to 0.10, have a total proven (P90) storage capacity of 95.7 TWh and a possible (P10) capacity of 853.2 TWh. This is, at least, sufficient to capture forecasted hydrogen demand for industrial application in Germany. Future work aims to consider local characteristics for individual storage sites.