Carbon Neutrality and Underground Hydrogen Storage

This study investigates current technology on large-scale underground hydrogen storage, a clean carbon neutral energy source to prevent the rapid increase of greenhouse gases, and to secure the sustainability of the Earth and mankind. Underground storage technology, which is used for natural gas storage, is widely accepted as the only technology suitable for large-scale hydrogen storage. Many countries have initiated underground hydrogen storage projects by exploiting geological structures such as salt caverns, depleted reservoirs, and aquifers. In Korea, an excavated rock cavern is a unique alternative for hydrogen storage because the other geological structures do not exist. In addition, rock cavern storage can be used for high-pressure gas or cryogenic liquid, and has an advantageous position in the land use, security, and safety aspects. Therefore, it will become an essential infrastructure for the stable and sustainable future hydrogen economy.