Underground hydrogen storage in salt caverns: Recent advances, modeling approaches, barriers, and future outlook

The need for renewable and environmentally-friendly energy has created a necessity for effective energy storage. Hydrogen, a carbon-neutral energy carrier, is a known flexible and adaptable alternative energy source. Dependable and extensive storage is essential because of the variability of renewable energy and the difficulties associated with its generation. Underground hydrogen storage (UHS) in salt caverns is considered a favorable choice due to its high withdrawal capacity, affordable cost, efficient space utilization, less cushion gas needs, and improved safety. Salt caverns bear inert hollow conditions with stable physical features and provide the most favorable possibilities for storing hydrogen for the future. This review analyzes the key problems associated with H2 storage in salt caverns and provides an essential trajectory for the storage of huge quantities of hydrogen. It also evaluates the feasibility of storing hydrogen using salt caverns of different sizes, depth, impact of convergence and rock geological structures with low permeability, significant creeps, and self-healing capabilities. Other basic aspects include the associated numerical models developed in the context of hydrogen storage in these systems. Thus, the primary controlling variables that contribute to hydrogen loss were critically evaluated from an economic perspective bearing in mind its future prospects.