Germany’s vast network of salt caverns has the potential to meet its domestic hydrogen storage demand and that of its European neighbours, according to a white paper published by the Federal Ministry of Economics and Climate Protection.

Demand for hydrogen storage is expected to grow rapidly in the coming decades on the back of growing use in industry and power generation, with seasonal fluctuations in renewable output emerging as a key driver. Germany’s storage requirements are expected to hit 2–7TWh by 2030, rising to 76–80TWh by 2045, according to the ministry. Europe-wide storage demand could hit more than 160TWh by 2050, it said.

About 250 salt caverns are used in Germany to store oil and natural gas, mainly in the north of the country. The relative proximity of these caverns to coastal regions, and thus offshore windfarms and green hydrogen production sites, as well as possible import routes, make them especially attractive for storage option for hydrogen.

A big advantage of salt caverns is their large storage volume. “The storage potential of individual caverns is enormous,” the ministry said in a whitepaper. Most caverns are at a depth of 500–2,500m, with a diameter of 50–100m and a height of 100–500m.

The caverns’ formation means they have a high level of tightness and long-term stability, which makes them “an ideal and safe storage medium for hydrogen”, it said. However, the repurposing of existing oil and gas storage caverns is technically demanding, as hydrogen has significantly different chemical and physical properties, the ministry said.

Proof of concept

Private sector efforts to develop hydrogen storage in Germany are gathering pace, despite the need for clearer regulation and risks for investors. Storage specialist EWE aims to start up a site in 2027. It says it has provided proof that hydrogen can be safely stored in salt caverns as part of a research project at its gas storage site in Ruedersdorf, near Berlin. The company is now transferring the knowledge gained from the construction and operation of the test cavern to larger volume caverns. It operates 37 salt caverns and reckons it has access to more than 15% of all German cavern storage facilities that are suitable for hydrogen.

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Author: Stuart Penson