Marensin
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, 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
691 km²
Size of the exploration area
concerned municipalities
13
concerned municipalities
Granted period
5 years
Granted period
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.
45-8 ENERGY and Storengy are also collaborating on the Grand Rieu exploration license, for which 45-8 ENERGY is the operator. Located in southwestern France, in the Pyrénées-Atlantiques department (64), this natural hydrogen exploration license also has the objective of deepening geological knowledge of the area and confirming its native hydrogen potential.
03
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.
04
Marensin exploration area
The license area covers 691km² and involves 13 municipalities in the French Landes:
Bias, Castets, Léon, Lesperon, Lévignacq, Linxe, Lit-et-Mixe, Mézos, Saint-Julien-en-Born, Saint-Michel-Escalus, Taller, Uza, Vielle-Saint-Girons.
05
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.
06
The work program
