MARENSIN exploration license
SOLID COLLABORATION FOR A NATIVE HYDROGEN EXPLORATION PROJECT IN SOUTHWEST FRANCE
01
Marensin 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 “Marensin” exploration license for an area of 691 km² in the Landes 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.
In addition to this exploration license, 45-8 ENERGY and Storengy are also working together on the Grand Rieu exploration license, in which 45-8 ENERGY, via its subsidiary 45-8 Grand Rieu, is the operator. Located in south-west France, in the Pyrénées-Atlantiques département (64), this Native Hydrogen exploration license also aims to deepen geological knowledge of the area and confirm the potential for native hydrogen.
02
A solid partnership between 45-8 ENERGY and Storengy
The license application is being submitted jointly with Storengy, a subsidiary of the ENGIE Group, as part of a partnership that will make it possible to draw on the respective expertise and resources of both parties.
Storengy is the project operator. The company is coordinating all the activities to be carried out on the exploration license and will carry out the studies and works.
45-8 ENERGY is a partner in the project. It is contributing its technical expertise to the studies and work that will be carried out.
Exploration area size
691 km²
Exploration area size
13
Municipalities
5 years
Valid period of the license
03
The license 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.
04
The exploration area
The license area covers 691km² and involves 13 municipalities in the French Landes Département (40) :
- Bias
- Castets
- Léon
- Lesperon
- Lévignacq
- Linxe
- Lit-et-Mixe
- Mézos
- Saint-Julien-en-Born
- Saint-Michel-Escalus
- Taller
- Uza
- Vielle-Saint-Girons.
05
Native Hydrogen
The license application is exclusively for native hydrogen.
Is native hydrogen natural?
Native hydrogen is produced naturally in the subsurface. As such, its formation requires no critical materials, no anthropogenic energy and no impact on available fresh water resources.
How is hydrogen formed?
Native hydrogen is formed by the transformation of a rock from the earth’s mantle, reacting with water as it seeps through faults. This process, known as serpentinization, generates a rock called serpentine, as well as native hydrogen.
Is native hydrogen a carbon-free resource?
Yes, because it is produced naturally in the subsurface, native hydrogen is a totally carbon-free resource. Its production would therefore make it possible to envisage low-cost, low-carbon production to serve the energy transition of the south-west and of France as a whole.
Why produce native hydrogen?
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.
Is it possible to find other gases?
Indeed, other resources could potentially be associated with native hydrogen. Helium, for example, could be associated! In the event that other resources are found, 45-8 ENERGY’s ambition is to exploit all subsurface resources.
06
The work program
07
The license key steps
Theoretical dates. The steps to follow will depend on how long it takes to process the application with the authorities.
