VTT Technical Research Centre of Finland and the Geological Survey of Finland (GTK) have outlined lined bedrock caverns for storing hydrogen, a potential buffer against swings in renewable hydrogen production for industrial users.
VTT announced findings from the joint study Oct. 19. Researchers put the conceptual construction cost of a 40,000-cubic-meter cavern at about €30 million. They estimate that planning, permitting and construction would take four to five years.
The study’s more detailed model gives a reference cost of €27.3 million for a cavern of that size operating at a maximum pressure of 200 bar. It excludes hydrogen compressors, so the figure does not cover the full installed cost.
Finland lacks suitable salt formations for underground hydrogen storage, directing the study toward caverns excavated in crystalline bedrock. Those caverns would need a lining to contain the gas. In a separate assessment, GTK identified 63 potential sites in Northern Ostrobothnia and classified 11 as particularly promising, while saying each requires more investigation before construction.
Storage could help steelmakers, chemical producers and refiners maintain a steady hydrogen supply when production from renewable electricity fluctuates. The study says pipelines can help manage shorter swings, while balancing supply over several days calls for larger facilities.
The report says investment in Finland’s green hydrogen sector, including storage, requires substantial upfront spending without immediate returns. It calls for public investment support. VTT project leader Pasi Valkokari has also called for firm commitments from buyers to take the hydrogen.
Sweden has a smaller operating example. HYBRIT says its 100-cubic-meter steel-lined rock cavern in Luleå has stored hydrogen intermittently since 2022, and its temporary permit was extended until 2031.
VTT Senior Scientist Jutta Nyblom said researchers are preparing further work with industry partners to develop requirements for a Finnish pilot. The report says a medium-sized cavern could begin operating in the first half of the 2030s.
