Hydrogen storage

Hydrogen storage systems are indispensable for the success of the energy transition. Storage in salt caverns provides a highly promising method.

Wasserstoffspeicher Harsefeld

Why store hydrogen?

As a versatile energy carrier, hydrogen can make a significant contribution to the energy transition. It provides a crucial building block for decarbonising the economy and achieving the European climate targets. The market ramp-up of hydrogen is already in full swing. However, the development of a comprehensive hydrogen infrastructure needs to be advanced much more strongly. Germany faces particular challenges: in the north-west of the country there are large industrial clusters that will need large quantities of hydrogen in future. This will require a comprehensive hydrogen infrastructure for producing, transporting and storing hydrogen.

Hydrogen storage in salt caverns

Storengy Deutschland operates six natural gas storage facilities throughout Germany – three of which are cavern storage facilities in the north-west of the country. From a geological point of view, they are ideally located to create new salt caverns there. In addition, existing salt caverns that are currently used for natural gas storage can also be converted for hydrogen use. Storage in salt caverns offers flexibility to balance fluctuations in production and consumption. Storengy Deutschland can draw on decades of experience in storing natural gas and has extensive expertise in delivering highly complex industrial projects, including the planning, approval, construction and operation of underground and surface storage facilities.

Our network

We are involved in various working groups and associations to promote renewable hydrogen and power-to-gas.

Together we’re accelerating the energy transition!


Gasspeicher Harsefeld


Our reference project in Germany

SaltHy (Storage Alignment with Load and Transport of Hydrogen) is a lighthouse project in northern Germany on an industrial scale, in which green hydrogen regionally produced from wind turbines and photovoltaic systems is set to be stored in underground salt caverns at the Harsefeld gas storage facility. One or two new caverns will be added to the storage facility for this purpose. From 2030 onwards, approximately 30 to 100 million standard cubic metres of pure hydrogen will be stored in these caverns. A feasibility study is currently being prepared for this project.

The goal is to make this green hydrogen available to local customers from industry and the mobility sectors. Gasunie’s supra-regional pipeline network ("HyPerLink") and the "Hamburg Green Hydrogen Hub"’s distribution network can use this storage facility to compensate for the effects of fluctuations in production and consumption in their networks. This will promote the development of a green hydrogen economy in northern Germany and the creation of a European “H2 backbone”.

Further projects

Our reference projects in France and the UK


Storengy pools its expertise across national borders. Our teams in France and the UK are also involved in planning and implementing pioneering hydrogen projects.

HyPSTER is a pilot project for storing hydrogen in the salt caverns at Storengy’s storage facility in Étrez (France). In addition to carrying out a feasibility study, a 1 MW electrolyser has been under construction since 2021 which will be used to fill a cavern with hydrogen as well as conduct leakage and injection/extraction tests to study the behaviour of the gas in the cavern. The cyclic injection and withdrawal of hydrogen, which will be used as backup for the region, will be started in 2023. Sales markets in industry, green mobility or renewable gas applications are currently being identified to develop the project beyond the feasibility study.

In collaboration with Géodénergies, a scientific advocacy group for carbon-free energy, and the Institute of Excellence for the Energy Transition (Institut d’Excellence pour la Transition Energétique, ITE), this project is being carried out by a consortium consisting of the Armines research institute, the Ineris centre of excellence for industrial safety and environmental protection, the Office for Geological and Mining Research (Bureau de recherches géologiques et minières, BRGM), Air Liquide, Geostock, Brouard Consulting and Storengy. The project is supported by the Fuel Cells and Hydrogen Joint Undertaking (FCHJU) with a federal grant of €5 million.

A pre-feasibility study for expanding the electrolysis capacity to 10 MW has already been started.

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As the first large-scale commercial project in France, HyGreen Provence is based on a system of local renewable electricity generation. In several expansion phases, photovoltaic installations (550 MW) and wind turbines (450 MW) will be built to supply an electrolyser plant (350 MW or up to 600 MW) that will convert parts of the electricity produced into hydrogen. The hydrogen produced in this way will either be stored in Storengy’s underground storage facility in Manosque, transported by pipeline to industrial consumers in the Marseille region, or used to supply a network of “green” filling stations in the region and industry.  Storengy’s expertise, infrastructure and work in research & development for the production and storage of hydrogen above and below ground are crucial for the success of such a project.

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In the HySecure demonstration project, Storengy and its partners Inovyn and Element Energy are investigating the construction of a salt cavern for storing H2 in Stublach (UK), the largest natural gas storage facility in the UK. In this project (funded by the UK government), potential improvements in key components will be identified in terms of their compatibility with hydrogen storage. In a second phase of the project, a dedicated hydrogen cavern will be developed to store hydrogen for several H2 projects in North-west England (such as the use of stored hydrogen in buses in Liverpool and Manchester). The aim of the project is to demonstrate the feasibility of storing large quantities of hydrogen in newly constructed salt caverns at significantly lower costs than surface storage.

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RINGS (Research on the Injection of New Gases in Storages) is a research and development partnership investigating the behaviour of biomethane and hydrogen when mixed with natural gas in underground pore storage facilities. In collaboration with the University of Pau and the Teréga gas storage operator (France), the investigation is particularly focusing on what proportions of such “new gases” are possible in underground pore storage facilities. With the help of rock samples, microorganisms, storage water and variable gas compositions, they are reproducing the reservoir conditions in order to investigate the behaviour of the reservoir’s porosity at different concentrations of hydrogen and biomethane so that they can determine the highest possible concentration of the gases.

Do you have any questions or would you like to find out more? We look forward to hearing from you!


Daniel Mercer
Head of Business Development