A Systematic Review of Underground Hydrogen Storage in the United States: Technical, Economic, and Future Insights

Currently, more than 70% of the US energy comes from fossil fuels. Energy transition is the pathway to transforming the US economy as well as the global economy away from its current dependence on fossil fuels towards net-zero carbon emissions. This paper evaluates the technical, economic, and future viability of underground hydrogen storage (UHS) in the U.S., covering both operating and potential storage sites. As hydrogen demand is projected to rise from 10 million metric tons (MMT) today to 22-43 MMT by 2050, large-scale storage is essential. The study reviews three existing UHS sites, Spindletop, Clemens Dome, and Moss Bluff, alongside potential sites across 98 salt domes and depleted gas reservoirs. A systematic review approach was adopted, synthesizing data from peer-reviewed literature, government reports, and industry studies on UHS in the U.S. Operating sites were analyzed based on storage capacity, geological suitability, operational pressure, and end-use applications. Potential sites were evaluated using site screening criteria, economic modeling, and feasibility assessments to determine their storage potential and scalability. Hydrogen storage costs, infrastructure requirements, and regulatory considerations were examined. The study also incorporated modeling and simulation data to assess the critical synthesis of research gaps and trends. Findings indicate that Spindletop currently holds the highest hydrogen storage capacity at 906,000 m³ (44.28% of total U.S. storage), followed by Clemens Dome at 580,000 m³ (28.35%) and Moss Bluff at 566,000 m³ (27.37%). Economic evaluations show that salt caverns remain the most cost-effective UHS method due to low cushion gas requirements and high withdrawal rates. Still, depleted gas reservoirs could store significantly larger hydrogen volumes at lower costs. The study identifies key technical challenges, including hydrogen-induced embrittlement, microbial consumption (up to 20% loss in some formations), and pressure cycling effects that can reduce storage efficiency by 10-15%. Infrastructure remains a bottleneck, as the U.S. has only 1,600 miles of dedicated hydrogen pipeline, concentrated primarily in the Gulf Coast region, limiting scalability. This review quantifies the viability of both operating and potential UHS sites, integrating technical, economic, and regulatory perspectives. A review of recent UHS modeling studies in the U.S. identifies prevailing approaches, challenges, and research gaps, serving as a valuable reference for future modeling efforts and the advancement of underground hydrogen storage technologies.