Large-scale underground storage enabling steady supply of hydrogen for industry
October 9, 2026
Researchers from VTT Technical Research Centre of Finland, LUT University and Politecnico di Torino have studied how large-scale underground hydrogen storage can help industry maintain a continuous hydrogen supply when production depends mainly on variable wind and solar power. The study focuses on Oulu, Finland, and uses techno-economic optimisation to design hydrogen production systems following EU rules for sustainable hydrogen production.
The researchers modelled systems with different industrial hydrogen demand levels, both with and without lined rock cavern (LRC) storage. LRC’s refer to excavated underground storage spaces, designed to safely contain hydrogen or other gases and liquids even in large scale. The results show that LRC storage can cost-efficiently bridge periods when renewable electricity is scarce or expensive by storing hydrogen beforehand.
Key Findings:
-
The optimised storage capacity corresponded to roughly 30 days of hydrogen demand, highlighting the importance of multi-week storage in Finnish conditions.
-
The storage formed less than 6% of total hydrogen cost, while electricity remained the largest cost component.
-
The inclusion of storage enabled a continuous hydrogen supply based entirely on renewable hydrogen. Without storage, fossil hydrogen covered about 40% of annual demand.
-
The presence of storage incentivised a higher optimal wind power capacity, supporting renewable energy investments and deeper decarbonisation.
-
More flexible implementation of EU sustainable hydrogen regulations could reduce production cost with only minor climate impacts under Finnish conditions.
The research was supported by the HUG – Hydrogen UnderGround public research project with funding from Business Finland, and the JustH2Transit project of the Strategic Research Council within the Research Council of Finland.
Note: The preprint is currently being peer reviewed.