The key project achievements per WP are the following:
• WP1 activities: The modelling developed by INOVYN, ERM and STORENGY have helped determine the contributions salt caverns can make to H2 storage and what kind of services a salt cavern should provide to the market. These achievements have been fed into the demonstrator in the form of the cyclic tests profile.
• WP2 activities: ESK, BROUARD Consulting, ARMINES, in collaboration with STORENGY, have transferred methodologies originating from natural gas to hydrogen. These modelling tools allow the optimization of the plant operation from a technical and commercial point of view for the EZ53 cavern and future salt caverns. This WP also confirmed the geological potential of salt caverns as significant.
• WP3 activities: The WP3 activities were led by STORENGY. The WP3 activities started in January 2021, with the launch of design activities. The purchase order for the electrolyser was placed with ELOGEN in August 2021. The permit to store 3 tons of hydrogen in EZ53 was granted to STORENGY in May 2022. Construction began mid-2022, leading to a well workover in March 2023. The first hydrogen injection into the EZ53 well took place on October 3rd 2024, which was followed by the successful tightness testing completed in early November 2024. An additional quantity of 2.4 tons of hydrogen was then injected in November and December 2024. This was followed by over 100 cyclic tests which were completed in April 2025. Final venting and rebrining of the cavern were concluded on May 28th, 2025. The commissioning and start-up of the hydrogen production site is expected by the end of September 2025.
• WP4 activities: ERM developed a cost analysis to understand the factors affecting the business case for salt cavern storage and costs for the end user. The work done also enables to refine the approach for identification of suitable sites for future H2 storage projects in Europe. The cost of H2 storage has been shown to have the potential to reach c.0.20-1 €/kg of H2 consumed by end users.
• WP5 activities: INERIS, working closely with STORENGY and other partners, have assessed and defined ways of mitigating the risks related to storing H2, in terms of industrial safety. INERIS have been able to draw recommendations for the sector for future deployments.
• WP6 activities: AXELERA and project partners have not only successfully disseminated the findings from the project but also gathered key strategic information. In total, so far, there have been: 17 scientific publications, 46 presentations, 3 podcasts, and 2 workshops. There has been a high interest worldwide for the project: from Europe, the US and China. These efforts were recognized with one award – so far – and many articles in the press and the project was flagged as exemplary by the EU innovation radar.
• WP7 activities: ERM have successfully managed all the partners, keeping track of all the actions to be carried out, organizing and issuing the minutes of the steering committees, and advising all the partners in the process of preparing their financial and technical reports.
• WP8 activities: EQUINOR have successfully launched the micro-biological analyses of brine samples taken at the onset of the project and with samples taken right at the end of the hydrogen venting and cavern rebrining.
