Espoo – October 19, 2026 -- A 40,000 cubic metre underground hydrogen storage facility in Finnish crystalline bedrock would cost approximately EUR 30 million and take four to five years to deliver, including planning and permitting, according to a study by VTT Technical Research Centre of Finland and the Geological Survey of Finland GTK.
The Business Finland-funded HUG project is the first comprehensive assessment of hydrogen storage requirements under Finnish conditions. Nearly twenty companies active in Finland's hydrogen economy took part.
Finland lacks salt caverns, so bedrock storage must be engineered gas-tight
Salt caverns in Central Europe and the United Kingdom can store hydrogen because they are naturally gas-tight. Finland has no suitable salt formations. Caverns must be excavated in crystalline bedrock, and gas-tightness must be created with technical solutions. The researchers describe Finland as a test case for other regions without salt cavern access.
Underground storage is needed to balance hydrogen production and use over days and weeks, not just hours. Hydrogen transmission pipelines can provide short-term flexibility, but multi-day balancing requires large underground facilities.
Project delivers high-level storage concept covering design, risk and investment needs
The concept covers storage structure design, operating models, geological and safety requirements, technical and societal risks, investment needs and ecosystem models. Several technical, commercial and regulatory questions remain open.
GTK geologist Teemu Lindqvist said site selection, site investigations and material studies are essential to keep the surrounding bedrock stable and to maintain safety if hydrogen reacts with other materials.
Medium-scale demand of 10,000 to 40,000 cubic metres expected to grow rapidly
Finland's hydrogen economy is expected to develop in stages, starting with regional hydrogen clusters. Smaller storage solutions will suffice initially. Demand for medium-scale underground facilities of 10,000 to 40,000 cubic metres is expected to rise quickly. Dedicated storage is expected to become a critical enabler of commercially viable value chains by helping stabilise hydrogen prices and availability.
Satu Sipola, Vice President, Hydrogen and Power-to-X at Fortum Power and Heat, said the results give a strong foundation for large-scale storage within future hydrogen systems.
VTT and industry consortium prepare pilot-facility phase, call for public support
VTT and the industry consortium are preparing the next research phase. It aims to develop design requirements that enable a pilot facility and a replicable storage concept for wider deployment, according to Jutta Nyblom, who leads industrial collaboration at VTT.
VTT project leader Pasi Valkokari said public investment support is critical to keep storage projects moving without delay. He added that projects also need close value-chain collaboration, a stable and predictable regulatory environment, and firm offtake commitments.
Industrial partners include AFRY Finland, Danfoss Drives, Fortum Power and Heat, Gasgrid vetyverkot, Helen, Neste, St1, Sweco Finland, Valmet Automation and Vantaan Energia.