With increasing interest in developing green hydrogen infrastructure as a way to decarbonize the power, transportation and heating sector the storage of hydrogen becomes a crucial component. Although most present hydrogen storage techniques are of small-scale, the intermittent nature of renewable electricity and expected future green hydrogen production and consumption makes large-scale storage an important factor.
This study evaluates the techno-economic feasibility of storing hydrogen in an already-existing underground salt cavern, one of three large-scale gas storage systems. The work starts with an overview of the large-scale gas storage methods and the challenges associated with storing hydrogen. The current
existing salt cavern storage facility is discussed and is technically assessed for hydrogen storage. The investment and operating costs related to the hydrogen storage method were calculated using models developed, certain components of the model were modeled using Aspen simulation software, which was also used to calculate the cost associated with it. For various scenarios, the cost distribution and the Levelized Cost of Hydrogen Storage (LCHS) were estimated. Based on the outcomes, the LCHS ranged from a best case scenario of 0.34 e/kg to a worst case scenario of 1.94 e/kg. Sensitivity analysis was conducted for the various storage parameters, and based on the dominant component the Net Present Value(NPV) is assessed with an increased LCHS. To conclude the study an estimate for the electrolyser capacity required for the plant to operate continuously was determined.