Uniper to trial large salt cavern hydrogen storage in northern Germany

German state-run energy company Uniper is trialling the use of a former salt mine in northern Germany for large-scale hydrogen storage, public broadcaster NDR reported. The company plans to test the 3,000 cubic metre cavern's leak-tightness over the coming two years, and the space’s suitability for its integration into the country’s developing hydrogen grid. “This project can play a key role in launching Germany’s hydrogen economy,” said Olaf Lies, economy minister of Lower Saxony, where the cavern is located. Frank Holschumacher, head of Uniper’s gas storage department, said the cavern will be filled with green hydrogen at the end of September.

Based on the results of this initial trial run, the company will decide whether to expand the storage’s volume to allow for the storage of up to 250 gigawatt hours (GWh). This could cost another 350 to 500 million euros and would take up to five years . Uniper plans to build additional hydrogen storage with a combined capacity of up to 600 GWh by 2030 in several locations in the country.

A report by the Institute of Energy Economics at the University of Cologne (EWI) published earlier this year found that salt caverns could be an effective location for storing hydrogen in Germany due to their geological, physical and chemical properties. The report highlights that Germany could be a central location for hydrogen storage in Europe. On top of having many salt caverns, the country also has comparatively large amount of natural gas storage capacity which could be converted to hydrogen storage. By 2045, Germany’s demand for hydrogen storage capacity could be up to 104 terawatt hours, and converting natural gas storage capacity could make up around 30 to 33 terawatt hours of that.