Natural hydrogen reservoirs could be used for underground storage, study suggests

Transitioning the world to zero-carbon energy requires storing vast amounts of hydrogen. A new study led by Shanghai Jiao Tong University has suggested that geological formations with naturally trapped hydrogen offer proven containment for large-scale underground energy storage. For instance, take the Albanian chromite mine. Inside this mine, a bubbling pool releases nearly pure hydrogen gas into the air. Energy experts previously dismissed these natural geological anomalies as hazardous and rare. Today, scientists believe these subterranean formations could offer a reliable solution to the clean energy transition’s biggest storage challenge. “The findings suggest that natural hydrogen reservoirs may be viable candidates for underground hydrogen storage,” the researchers stated. Nature’s underground vaults Scaling hydrogen into a major energy source depends largely on securing viable, high-capacity storage sites. Typical subterranean options cannot meet these demands. Salt caverns present severe geographical constraints, while aquifers and depleted hydrocarbon fields lack demonstrated, long-term containment integrity for hydrogen gas. Hence, these conventional options remain inviable for supporting a large-scale hydrogen economy. The Bulqizë reservoir in Albania formed along a massive fault zone. Located within an uplifted section of oceanic crust known as an ophiolite, the Bulqizë reservoir generates its own continuous supply of clean energy. Deep underground, groundwater comes into direct contact with iron-rich minerals such as olivine, triggering a chemical reaction called serpentinization. This natural process splits water molecules and steadily produces pure hydrogen gas within the surrounding rock formations. It has safely trapped hydrogen for thousands of years. That geological track record prompted researchers Lei Hou, Zhengxin Zhang, and Fengshou Zhang to test a bold idea: if nature already built a leak-proof hydrogen vault, why not reuse it as a commercial storage warehouse? Using advanced fluid-flow and underground chemistry models, the research team analyzed 72 different operational scenarios to test the site’s limits. The results were interesting. Natural chemical reactions and dissolution would consume less than two percent of the stored hydrogen, proving the subterranean vault retains gas with exceptional efficiency. Furthermore, the models revealed the reservoir could hold between 350 million and 480 million cubic meters of gas while supporting a daily throughput of 750,000 cubic meters. Fault risk Perhaps the most surprising discovery involves the fault line itself. Pumping gas in and out of a seismic fault line sounds like a recipe for earthquakes, but cyclic testing over a 10-year period showed the exact opposite effect. Standard gas pressure spreads out across the rock formations, homogenizing subterranean forces and actually decreasing the risk of the fault slipping over time. “Over 10 years, hydrogen storage in the reservoir would decrease the risk of the fault slipping by redistributing gas pressure,” the team noted. Utilizing naturally sealed fault zones could also cut the capital investments typically required for hydrogen containment. Energy companies might save substantial capital by tapping naturally occurring subterranean structures rather than excavating artificial caverns or modifying depleted reservoirs. Currently, the study is model-based only. If explored further, this study could open a promising new pathway to global, large-scale clean energy storage by showing that naturally occurring hydrogen traps can double as high-capacity power banks. Get the latest in engineering, tech, space & science - delivered daily to your inbox.Mrigakshi is a science journalist who enjoys writing about space exploration, biology, and technological innovations. Her work has been featured in well-known publications including Nature India, Supercluster, The Weather Channel and Astronomy magazine. If you have pitches in mind, please do not hesitate to email her.