Capacity and cost analysis of underground hydrogen storage in salt caverns in the United States

Abstract

Hydrogen storage has been playing a key role in the energy transition as a clean energy. To address the challenges in large-scale and long-term hydrogen storage, salt caverns have become a promising solution compared with other hydrogen storage methods since salt caverns have high deliverability, exceptional containment, minimal contamination risk by microorganisms or methanogenesis of stored hydrogen, inert chemical behavior with respect to hydrogen, and possess favorable mechanical properties, allowing for repeated withdrawal and injection cycles. Therefore, analyzing the techno-economic feasibility of hydrogen storage in salt caverns has become an essential topic. However, there is no accurate and efficient tool to estimate the capacity and cost of hydrogen storage in salt caverns. Existing workflows have limitations due to restricted assumptions such as the constant volume and cushion gas amount for all the salt caverns in the same salt layer with a fixed geometry, which do not allow calculations for the capacity and cost of hydrogen storage in both individual salt caverns and specific salt layers. Moreover, these workflows are performed manually, which limits their efficiency and further application. Hence, to address this challenge, we developed an automatic module for the techno-economic analysis of hydrogen storage in salt caverns, which can be used to estimate the techno-economic feasibility of not only a single salt cavern but also a certain salt layer. This work provides essential guidance for underground hydrogen storage in salt caverns by providing the first assessment of UHS potential in salt caverns across the US by highlighting six rock salt basins—Delaware, Midland, Palo Duro, Anadarko, Michigan, and Appalachian—that have significantly greater potential for total working gas capacity.