A comprehensive review of the mechanisms and efficiency of underground hydrogen storage

Underground Hydrogen Storage can be proven very beneficial for recurring supply of clean energy throughout the world. This paper reviews different challenges like microbial growth, well integrity, and geochemical reactions faced when hydrogen is stored in subsurface. The mechanisms involved in underground hydrogen storage, monitoring techniques and optimization of injection-withdrawal techniques are also analysed by incorporating both field and laboratory research studies. If the economics of any technology is not taken into account, it will not be deemed as a common technique. Keeping that in mind, the road map for the implementation and economic aspects of hydrogen storage are discussed. Lastly, conclusions and recommendations for future research are presented.