Geological hydrogen storage in saline aquifers is necessary due to their large capacities, enabling long-term and short-term storage and providing a secure and cost-effective option for integrating hydrogen into the energy system. Currently, there are no operational saline aquifer storages for hydrogen in Germany. However, there is an urgent need for investigating the desired capacity and performance of hydrogen underground storage facilities in deep saline aquifers as one of the most promising geological environments.
In this study, the sedimentary Stuttgart formation at the Ketzin site in Brandenburg, Germany, is assessed for geological hydrogen storage using an open-source reservoir simulator. The site has already been used for town gas and natural gas as well as for pilot CO2 storage in the past decades. The experience from these storage operations can be transferred to a potential hydrogen storage system.
The goal of the investigation is to evaluate the influence of geological parameters of the heterogeneous formation such as porosity, permeability, salinity, and capillary pressure on flow rates, quantities as well as on the recovery rate. The range of each parameter agrees with the measured uncertainty of petrophysical data. The results of the pre-feasibility study are then considered in the context of the regional hydrogen economy.
Overall, this multidisciplinary approach combines numerical simulations, geological parameters, and regional economic considerations. Future studies will focus on optimizing the operational parameter to minimize well-head pressure difference between charge and discharge cycles, to maximize production rates, and to achieve net-zero cumulative injection of hydrogen over time.