Hydrogen Pilot STorage for large Ecosystem Replication (HyPSTER), the renewable hydrogen storage demonstrator in a salt cavern located in Etrez (France), is entering its operational phase. On the 3rd of October 2024, the first hydrogen molecules were injected into the EZ53 salt cavern. A decisive step for this project, supported by the European Union's Clean Hydrogen Partnership.

HyPSTER is the first salt cavern hydrogen storage demonstrator. It aims to test and validate the role of hydrogen storage in the hydrogen value chain, with a view to eventually replicating it on a larger scale and supporting the development of the hydrogen industry in Europe.

Since the 3rd of October 2024, several injections of hydrogen have been carried out to confirm that the well is hydrogen-tight in successive stages throughout its depth.

At the end of this leak-test phase, around two additional tons of hydrogen will be injected to enable simulations of hydrogen injection and withdrawal cycles to be carried out in the cavern over a period of more than three months. These tests are decisive in confirming the feasibility of large-scale hydrogen storage in a salt cavern.