Mantle8 Awarded Exclusive Natural Hydrogen Permit in France, Launches Hydrogeco Project
Mantle8 has been awarded an exclusive five-year exploration permit for natural hydrogen and helium in the French Pyrenees, marking one of the most significant regulatory milestones for the emerging European natural hydrogen sector.
The permit, known as the "Permis de Comminges," covers approximately 739 square kilometres across the Haute-Garonne and Hautes-Pyrénées departments. Granted by the French Ministry of the Economy, Finance and Industrial, Energy and Digital Sovereignty, it authorizes Mantle8 to undertake exploration activities, including geophysical surveys, across the entire permit area before seeking approval for drilling operations.
Alongside the permit award, the company has officially launched the Hydrogeco Project (Hydrogène géologique du Comminges), a large-scale exploration and demonstration initiative designed to advance the project from resource evaluation toward potential commercial development. The consortium brings together scientific institutions, technical partners, transportation operators, industrial users, and local stakeholders under a collaborative framework.
According to Mantle8, the permit application was supported by data generated through the company’s proprietary HOREX® exploration technology, which last year completed what the company describes as the world’s first four-dimensional imaging of an active underground natural hydrogen system at the project area. The company has already begun geophysical surveys across the full permit area to further characterize subsurface hydrogen systems and identify future drilling targets.
The announcement follows a period of significant financial momentum for Mantle8. The company recently completed a €31 million Series A financing round and secured an additional €2.06 million grant from the European Union’s Just Transition Fund, bringing total capital raised to approximately €37 million. The funding is intended to support continued deployment of the company’s exploration technology and future drilling campaigns, subject to regulatory approvals.
Full press release is attached below:
Grenoble, France - 3 June 2026 - The French government has awarded an exclusive five-year exploration permit for natural hydrogen and helium to G&OL SAS, a wholly owned subsidiary of Mantle8. The "Permis de Comminges" covers 739 square kilometers across the departments of Haute-Garonne and Hautes-Pyrénées in the French Pyrenees and was published in the Journal Officiel de la République Française on 11 April 2026.
The permit was granted by the Ministry of the Economy, Finance and Industrial, Energy and Digital Sovereignty following a formal application process that included public consultation and review by regional authorities. It authorises Mantle8 to conduct exploration activities, including geophysical surveys, across the full permit area ahead of seeking final approval to commence drilling.
Alongside the permit award, Mantle8 is launching Hydrogeco (Hydrogène géologique du Comminges), its flagship natural hydrogen exploration and demonstration project in the Pyrenees. Hydrogeco brings together research institutions, technical partners, transportation operators and downstream industrial offtakers within a collaborative framework designed to support the project’s progression from exploration through to potential commercial development.
"This permit and the launch of the Hydrogeco Project represent a significant step forward for natural hydrogen in Europe," said Emmanuel Masini, Founder and CEO of Mantle8. "Energy sovereignty has become a strategic imperative across the continent, and France is now creating the regulatory conditions for a domestically produced, low-carbon hydrogen resource to be developed at scale. The consortium model is central to our approach because a resource of this scale and complexity will only succeed if it is developed in genuine partnership with local communities, scientific institutions and industrial stakeholders. We have the proven technology, the capital and now the regulatory framework to advance this project through the critical next phase of exploration."
Last year, Mantle8 completed the world's first 4D imaging of an active underground natural hydrogen system at the Hydrogeco prospect using its proprietary HOREX® multiphysics exploration technology. The data signalled the presence of an active hydrogen-generating source that replenishes sealed reservoirs and underpinned the permit application. Since receiving the permit, Mantle8 has commenced geophysical surveys across the full 739 square kilometre area to build a comprehensive picture of subsurface hydrogen dynamics. This data will be used to identify the most promising reservoir locations.
Julien Perrutel, Director of the Hydrogeco project, is based in the region and serves as the primary point of contact for regulatory authorities, local population and commercial partners. "Our presence in the field is fundamental to how this project will succeed," he said . “Since the launch of the project, we have engaged in a transparent, science-based dialogue with all local stakeholders, including elected officials, intermunicipal authorities, environmental associations, economic actors and citizens. We will continue this approach throughout the project’s development, with the ambition of creating lasting value for the local area.”
In a sign of growing institutional confidence in natural hydrogen as a credible component of Europe's energy future and Mantle8’s technology led approach, the company recently closed a €31 million Series A funding round as well as securing a €2.06 million grant from the EU Just Transition Fund to industrialise its core exploration technologies, bringing total investment in the company to €37 million. The capital will fund the deployment of Mantle8's exploration technology across its prospect portfolio and support the company's planned drilling campaigns, subject to the necessary regulatory approvals.
Natural hydrogen is produced by ongoing geological processes such as serpentinization, where water reacts with iron-rich rocks deep underground. Unlike manufactured hydrogen, it requires no electrolysis nor fossil fuel inputs, offering a low-carbon source of hydrogen at a fraction of the energy intensity of current production methods. Mantle8's proprietary technology stack is purpose-built for analysing natural hydrogen systems, enabling the company to pinpoint reservoirs that contain free gas at high purity and sufficient pressure to enable unassisted extraction.
About Mantle8
Mantle8 is a natural hydrogen exploration company founded in 2019 and headquartered in Grenoble, France. The company has raised €37 million (US$44 million) from investors including Sandwater, Breakthrough Energy Ventures, Bpifrance Green Ventures, IP Group, Wind Capital and Calderion. Mantle8 develops proprietary subsurface modelling and exploration technologies, including HOREX®, a multiphysics platform that produces 4D images of active underground hydrogen systems. For more information, visit mantle8.com.
About the Hydrogeco Project
The Hydrogeco Project (Hydrogène géologique du Comminges) coordinates the exploration and development of natural hydrogen resources across 739 square kilometres of the Pyrenean foothills, spanning 109 municipalities across seven intermunicipal communities in Haute-Garonne and Hautes-Pyrénées. Hydrogeco maintains ongoing dialogue with local stakeholders, integrating environmental and socio-economic considerations throughout the project lifecycle. For more information, visit mantle8.com/hydrogeco.
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