351m refinancing package to develop ‘hydrogen-ready’ cavern storage in Germany

German-headquartered investment firm Patrizia has secured a €351m refinancing package to support the development of its Etzel underground storage facility in northern Germany into a hydrogen-ready energy storage hub. The refinancing extends the existing loan by five years at improved pricing and will be used by Patrizia’s majority-owned subsidiary, Storage Etzel, to advance the site’s transition from conventional fossil fuel storage toward large-scale hydrogen storage. The Etzel facility is one of Europe’s largest underground energy storage sites, comprising 75 caverns in total. Of these, 51 caverns are currently used for natural gas storage, with a combined capacity of 3.9 billion cubic meters, while the remaining 24 caverns are used for oil storage and can hold up to 10 million cubic meters. The site has already demonstrated its hydrogen potential through the H2Cast pilot project, during which hydrogen molecules were successfully injected into the caverns. Strategically located near the port of Wilhelmshaven, the Etzel site sits close to several planned green hydrogen production projects and hydrogen import terminals, positioning it as a key piece of future hydrogen infrastructure. Patrizia also noted that the facility could be expanded to as many as 99 caverns, although it did not confirm whether the current financing would be used for this expansion. Patrizia said the refinancing underscores strong lender confidence in the long-term value of the Etzel facility and reinforces its role as a critical asset in supporting Europe’s energy transition, industrial decarbonization, and the development of a hydrogen-based energy system.