Vallourec obtains the qualification of its hydrogen storage solution and launches commercialization
Vallourec, a world leader in premium seamless tubular solutions, announces the official qualification of Delphy, its vertical gaseous hydrogen storage solution, by DNV.
A world first, Delphy enables the storage of 1 to 100 tons of hydrogen under maximum safety conditions. Thanks to its minimal footprint, this vertical system - extending up to 100 meters underground - meets the challenge of complex and demanding industrial environments. It targets both green hydrogen producers and industrial players such as synthetic fuel producers (e-SAF, e-methanol), green ammonia producers, steelmakers, and refineries.
The Delphy solution is the result of Vallourec's longstanding expertise and know-how and is based on proven technologies - tubes and connections - that have demonstrated excellent tightness and corrosion resistance.
Launched in 2022, the project has involved around thirty researchers and experts, particularly in the areas of high-precision threading, heat treatment, and non-destructive testing. Since the inauguration of its demonstrator in December 2023, Vallourec has followed a rigorous process of development, testing, and validation of its hydrogen storage technology, culminating today in the qualification of Delphy. This qualification by recognized experts guarantees the solution’s safety and reliability and marks a key milestone towards its commercialization.
Vallourec has already signed two Memorandums of Understanding (MoUs): one with H2V, for green hydrogen production and utilization projects, and one with NextChem Tech, for green hydrogen and green ammonia projects. Around fifty projects - in France and internationally - are currently under discussion, representing potential revenue of approximately €2 billion.
This qualification comes at a time when demand for storage infrastructure is expected to grow, to adapt to the intermittent and flexible nature of green hydrogen production. Demand for the Delphy storage solution will be fuelled by European regulations, which require storage solutions to pair with renewable electricity production, and by the French hydrogen strategy, which encourages green hydrogen producers to operate flexibly to contribute to power grid stability.
Philippe Guillemot, Chairman of the Board of Directors and CEO of the Vallourec Group, commented: "The qualification of Delphy illustrates Vallourec’s ability to leverage its industrial and technological expertise for new energy solutions. Thanks to the excellence of our teams, we are able to offer this unique solution that meets the challenges of developing the global hydrogen sector. This key milestone reinforces our position in the hydrogen market and our leadership in supporting global decarbonization efforts."

Santiago Blanco, Executive Vice President & Director for Southern Europe, Energy Systems at DNV commented "DNV is proud to validate Vallourec’s Delphy hydrogen storage solution—a milestone in safe, scalable hydrogen infrastructure. With our Energy Transition Outlook model projecting a need for 188 million tons of hydrogen annually by 2050, flexible storage like Delphy is
critical to bridge renewable supply and industrial demand. As hydrogen unlocks decarbonization for hard-to-electrify sectors, independent technical assurance will be key to accelerating deployment and building market confidence."