HyCAVmobil (Hydrogen Cavern for Mobility) - Investigation of salt caverns as a potential storage site for hydrogen

For a reliable supply of clean hydrogen, a holistic infrastructure must be built, as is also the case with fossil gases. In addition to the expansion or conversion of the grid, this also includes the storage of the gas. How we can reliably store hydrogen in the long term is becoming increasingly important for sector coupling.

The HyCAVmobil project of EWE Gasspeicher GmbH and the German Aerospace Center (DLR) Institute for Networked Energy Systems is therefore looking at the sustainable and safe storage of 100 per cent pure hydrogen in salt caverns - a pioneering project.

Currently, salt caverns are used as safe long-term storage for energy sources such as natural gas or crude oil. In the context of the energy transition, this type of storage is now also being considered for hydrogen. In order to store hydrogen in the long term and then use it in the field of fuel cell mobility, the HyCAVmobil (Hydrogen Cavern for Mobility) project will research the conditions under which pure hydrogen can also be stored in salt caverns. The main focus is on how storage and retrieval affect the quality of the hydrogen.

Following initial laboratory-scale investigations, EWE and its Lower Saxony project partner have been building an underground cavern storage facility in Rüdersdorf, Brandenburg, since February 2021. In a first step, a drilling rig is erected and the salt dome is flushed out with water at a depth of 1,000 meters. This will create a cavity of 500 cubic meters, in which up to six tons of hydrogen will be stored in the future. By way of illustration, this quantity is enough to fill up around 1,000 hydrogen cars. If the project is successful, the findings of this project can easily be transferred to caverns with 1,000 times the volume, according to those responsible. That would be an important step toward large-scale hydrogen use.

The project is funded as part of the National Hydrogen and Fuel Cell Technology Innovation Programme and receives a funding grant of around 6 million euros from the Federal Ministry of Transport and Digital Infrastructure (BMVI).