Following its Series A funding round, Mantle8 is launching the Hydrogeco project in order to develop natural hydrogen in the Pyrenees.
Grenoble, France – 3 June 2026 – The French government has granted an exclusive five-year exploration licence for native hydrogen and helium to G&OL SAS, a subsidiary wholly owned by Mantle8. The «Comminges Licence» covers an area of 739 km² split between the departments of Haute-Garonne and Hautes-Pyrénées, in the French Pyrenees. It was published in Official Journal of the French Republic 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 procedure including, notably, a public consultation and a review by the regional authorities. It authorises Mantle8 to carry out exploration activities, including geophysical surveys, across the entire permit area, ahead of any potential application for authorisation to begin drilling operations.
Alongside the granting of the licence, Mantle8 is launching Hydrogeco (Comminges Geological Hydrogen), its flagship exploration and demonstration project dedicated to natural hydrogen in the Pyrenees. Hydrogeco brings together research organisations, technical partners, transport stakeholders and industrial hydrogen users within a collaborative framework designed to support the project from the exploration phase through to potential commercial development.
«This permit and the launch of the Hydrogeco project constitute an important milestone for natural hydrogen in Europe,» stated Emmanuel Masini, founder and CEO of Mantle8. Energy sovereignty has become a major strategic issue across the continent, and France is now creating the regulatory conditions enabling the large-scale development of a locally produced, low-carbon hydrogen resource. The consortium model is at the heart of our approach, because a resource of this scale and complexity can only be successfully developed through a genuine partnership with regional authorities, scientific institutions and industrial stakeholders. We have proven technology, the necessary capital and now the regulatory framework to advance the project into this crucial new exploration phase.«
Last year, Mantle8 made the world's first 4D imaging of an active natural hydrogen subterranean system on the Hydrogeco site, thanks to its proprietary multi-physical exploration technology HOREX®. The data obtained indicated the presence of an active source generating hydrogen and feeding confined reservoirs, and helped to support the permit application.
Since obtaining the licence, Mantle8 has launched geophysical campaigns across the entire 739 km² in order to obtain a comprehensive understanding of hydrogen dynamics in the subsurface. This data will be used to identify the most promising reservoir zones.
Julien Perrutel, Hydrogeco project director, is based in the region and is one of the main contacts for regulatory authorities, local populations and business partners.
«Our presence on the ground is fundamental to the success of the project,» he stated. «Since the project was launched, we have engaged in transparent, science-based dialogue with all local stakeholders, notably elected officials, intermunicipal bodies, environmental associations, economic actors and citizens. We will continue this approach throughout the project's development, with the ambition of creating sustainable value for the local area.»
Against a backdrop of growing institutional trust in natural hydrogen as a credible component of Europe's energy future and in Mantle8's technological approach, the company recently closed a €31 million Series A funding round, as well as obtained a €2.06 million grant from the Just Transition Fund, aimed at industrialising its main exploration technologies. The total amount of investment in the company thus reaches €37 million.
This funding will make it possible to deploy Mantle8's exploration technologies across its entire portfolio of prospects and to support the company's planned future drilling campaigns, subject to obtaining the necessary regulatory approvals.
L’natural hydrogen is produced by continuous geological processes such as serpentinisation, during which water reacts with iron-rich rocks deep underground. Unlike industrially produced hydrogen, its formation requires neither electrolysis nor the use of fossil fuels, thus offering a low-carbon source of hydrogen with a significantly lower energy intensity than current production methods.
The proprietary technologies developed by Mantle8 are specifically designed to analyse natural hydrogen systems. They enable the company to identify reservoirs containing free gas with a high degree of purity and sufficient pressure to allow unassisted extraction.
About Mantle8
Mantle8 is an exploration company specialising in natural hydrogen, founded in 2019 and based in France. The company has raised €37 million ($44 million) from investors including notably 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 making it possible to produce 4D images of active underground hydrogen systems.
For further information: mantle8.com
About the Hydrogeco project
The project Hydrogeco (Comminges Geological Hydrogen) coordinates the exploration and development of natural hydrogen resources in a territory of 739 km² located in the Pyrenean foothills, spanning 109 municipalities spread across seven intercommunal authorities of Haute-Garonne and Hautes-Pyrénées.
Hydrogeco maintains an ongoing dialogue with local stakeholders and integrates environmental and socio-economic considerations throughout the project lifecycle.
