Grand-Rieu
The emergence of a native hydrogen industry in the French Pyrénées-Atlantiques region!
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Grand Rieu exploration license
Bibliographic research and preliminary field studies are being carried out between 2021 and 2022, as part of a research project called H2NA. Co-financed by the Nouvelle-Aquitaine Region and academic and industrial partners such as 45-8 ENERGY, BRGM, CVA Group, ENGIE, UPPA and Storengy, the H2NA project confirmed the area’s potential for natural hydrogen and defined the contours of an exploration license in a high-potential zone.
In March 2025, 45-8 ENERGY and Storengy obtained the “Grand Rieu” exploration license for an area of 266 km² in the Pyrénées-Atlantiques department for a period of 5 years. Granted by the French Ministry of Ecological Transition, this license aims to deepen geological knowledge of the area and confirm its natural hydrogen potential.
The perimeter chosen for this application is deliberately vast, in order to gain a global understanding of the geology of the area, and then to target high-potential zones as data is acquired.
If our hypotheses are validated, we envisage the joint development of natural hydrogen and any associated gases. Such production would encourage the use of hydrogen as a low-carbon energy source, and contribute to the energy transition in the south-west of France.
Size of the exploration area
266 km²
Size of the exploration area
concerned municipalities
36
concerned municipalities
Granted period
5 years
Granted period
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45-8 ENERGY and Storengy: a solid and unique partnership
45-8 ENERGY and Storengy, a subsidiary of the ENGIE Group, are combining their strengths and expertise in this application for natural hydrogen exploration.
45-8 ENERGY, through its subsidiary 45-8 Grand-Rieu, is the project operator. It coordinates all activities carried out on the license and will conduct studies and works.
Storengy is a partner in the project. The company is contributing its technical expertise to the studies and work that will be carried out.
45-8 ENERGY and Storengy are collaborating on a second natural hydrogen exploration project. Named “Marensin,” the project is located in the Landes department.
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The license's goals
Identify the location of hydrogen-generating rocks and understand the migration path of hydrogen to the surface or to geological structures where it may have accumulated.
Precise characterization of the area’s geology and the zones most conducive to hydrogen accumulation.
Quantify the volumes of hydrogen that could be stored in the subsurface, and assess the technical and economic potential, all with the utmost respect for the environment.
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The exploration area
The license area covers 266km² and involves 36 municipalities in the French Pyrénées-Atlantiques Département:
Ainharp, Angous, Aren, Aroue-Ithorots-Olhaïby, Arrast-Larrebieu, Barcus, Berrogain-Laruns, Charre, Charritte-de-Bas, Chéraute, Dognen, Domezain-Berraute, Espès-Undurein, Esquiule, Géronce, Geüs-d’Oloron, Gurs, Jasses, Lay-Lamidou, Ledeuix, L’Hôpital-Saint-Blaize, Lohitzun-Oyhercq, Lucq-de-Béarn, Moncayolle-Larrory-Mendibieu, Moumour, Oloron-Sainte-Marie, Orin, Poey-d’Oloron, Préchacq-Navarrenx, Roquiague, Saint-Goin, Saucède, Sus, Verdets et Viodos-Abense-de-Bas.
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Natural hydrogen
Natural hydrogen
The exploration license application relates exclusively to natural hydrogen.
Native hydrogen is produced naturally by the planet in the subsurface. Its formation therefore requires no critical materials or anthropogenic energy and has no impact on available drinking water resources. “Native hydrogen,” “natural hydrogen,” and “white hydrogen” are all terms used to describe this hydrogen produced naturally by our planet.
The natural formation of hydrogen in the subsurface can have several origins. In the context of the Grand Rieu exploration license, hydrogen is formed through the transformation of rock from the Earth’s mantle reacting with water that seeps through existing faults. This process, called serpentinization, generates a rock called serpentine, as well as natural hydrogen.
Yes! Natural hydrogen, produced naturally underground, is a totally carbon-free resource. Its production requires no critical materials, anthropogenic energy or water, and enables the resource to be valorized at extremely competitive costs, making a direct contribution to the energy and ecological transition.
Native hydrogen has a role to play in the decarbonization of industry and mobility. This type of hydrogen could easily be integrated into the existing low-carbon hydrogen mix as a natural, decarbonized and competitive resource.
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The work program
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Key steps
Subsidiary 45-8 Grand-Rieu
The company 45-8 Grand-Rieu is 94% owned by 45-8 ENERGY.
Two other partners are participating in the project, contributing their expertise in the native hydrogen sector.
Lavoisier H2 Geoconsult
M&U
