Hydrogen is expected to make significant contributions as an energy carrier for decarbonizing the energy system and meeting net-zero emission targets. Emissions free hydrogen may be produced via both steam methane reforming of natural gas with geological carbon storage or electrolysis using renewable electricity. Solar and wind energy are intermittent but hydrogen production and storage can help reduce or eliminate intermittency if storage is done economically and at large scale. Underground formations have the potential to store many multiple TWh of energy due to the large volumetric capacity of depleted oil and gas reservoirs as well as saline formations. Although hydrogen storage has been successfully implemented in salt caverns in the UK and the US Gulf Coast for over 30 years, the geographic availability of evaporitic formations with suitable thickness and extent offers limited storage capacities. Subsurface saline aquifers and depleted oil/gas fields offer storage capacity that is several orders of magnitude larger than that of salt caverns; thus, subsurface geologic formations have the potential for hydrogen storage at very large scales

The objective of our research is to understand the properties and conditions of subsurface reservoirs to enable temporal storage of high purity hydrogen. This understanding of optimal reservoir properties guides screening and identifying potential sites for underground hydrogen storage. Our research efforts are interdisciplinary, combining geospatial mapping, geology, geophysics, petrophysics and reservoir engineering, to identify and select sites for underground hydrogen storage. In addition, we carry out reservoir simulation to understand the long-term effects of injection and withdrawal of hydrogen. We are also identifying relevant experimental work to aid in our understanding of how hydrogen reacts with components of the subsurface during storage.

Aspects of our work in the area of seal durability also apply here as hydrogen storage formation seals will encounter a molecule (H2) that they have not encountered in large concentration as well as seals will be subjected to cyclic depletion and withdrawal as hydrogen is withdrawn and injected. Monitoring efforts described under CCUS also crossover into this area for studying injection/withdrawal operations at formation scale.