Insight into Underground Hydrogen Storage in Aquifers: Current Status, Modeling, Economic Approaches and Future Outlook

Abstract

Aquifers are considered one of the most eco-friendly forms of underground hydrogen storage due to their widespread availability, natural porosity, minimal requirement for structural modification, and reduced environmental disruption compared to other options, such as salt caverns or depleted reservoirs. However, the number of active aquifer-based hydrogen storage projects is limited, as most current storage efforts focus on depleted fields and salt caverns. Unlike salt caverns, which require extensive mining and energy-intensive leaching processes or depleted reservoirs that may pose risks of residual hydrocarbons contaminating stored hydrogen, aquifers typically involve fewer invasive preparatory measures. Additionally, their wide geographical distribution makes them accessible without significant infrastructure development, reducing the carbon footprint associated with site preparation and operation. With careful monitoring to mitigate risks, such as microbial hydrogen consumption, aquifers offer a sustainable and less intrusive alternative for large-scale hydrogen storage. This is crucial for scaling up hydrogen as a primary energy carrier in global decarbonization efforts. While aquifers show high potential, their use for hydrogen storage remains underdeveloped, requiring significant research and development investment. Hydrogen’s interaction with aquifer materials poses risks, necessitating rigorous site assessments and mitigation strategies. Despite existing challenges, economic assessments indicate that aquifer costs are unpredictable due to a lack of reservoir characterization. This review further discusses the geological properties, H₂ loss pathway and mitigation strategies, sealing technologies, potential storage sites, challenges and economic analysis of H₂ storage in aquifers.