A €2.06 million EU grant gives the Grenoble deep-tech startup non-dilutive runway to industrialise a four-component technology platform, and moves it one step closer to its first commercial drilling campaign.
Fourteen months after closing a €3.4 million seed round backed by Bill Gates’ Breakthrough Energy Ventures and Kiko Ventures, Mantle8 has secured a second source of capital to advance its work, this time from the European Union. The Grenoble-based natural hydrogen exploration company has been awarded €2.06 million from the EU’s Just Transition Fund, channelled through the FEDER/FSE+/JTF 2021–2027 regional programme managed by the Auvergne-Rhône-Alpes region. The grant is non-dilutive, meaning no equity changes hands.
The award forms part of a broader €4.84 million research and development programme running through 2028, and brings Mantle8’s total funding to approximately €5.46 million. All activity under the programme will be anchored in Grenoble and the wider Auvergne-Rhône-Alpes region, building on the area’s established base of geoscience expertise.
Mantle8’s technology platform is built around four proprietary systems. GeoLogix® is the company’s prospect generation algorithm, which scans geological data to identify locations where the conditions for natural hydrogen production, the right source rocks, active generation zones, and viable reservoir structures, are all present.
HOREX® is the company’s multiphysics imaging system, which places passive seismic sensors across a field site to reconstruct a four-dimensional view of the entire hydrogen-generating system underground. APoGeH® handles quantification, using liquid, gas and rock samples to evaluate the volume and composition of hydrogen a given system could yield. Simul8 is the digital twin modelling engine that ties the other three together into simulations of full hydrogen systems.
The EU funding will support all four components. HOREX® development continues at Mantle8’s Hydrogeco prospect in the French Pyrénées, the site where, in October 2025, the company produced what it described as the world’s first three-dimensional images of an active underground natural hydrogen system.
A dedicated APoGeH® geochemistry laboratory will be built at Mantle8’s Grenoble headquarters, replacing the need to rely on external facilities for sample analysis. GeoLogix® will receive upgrades to introduce greater automation and higher-resolution imaging. PhD researchers will be recruited to work alongside university partners and Mantle8’s scientific advisory board.
The grant does not fund exploration drilling directly. Its purpose is to industrialise Mantle8’s technology stack, improving the efficiency and precision of its systems so they can be deployed faster and at greater scale. The practical ambition is to reduce the time and cost between identifying a promising hydrogen reservoir and the point at which a drilling decision can be justified.
Mantle8 has been moving quickly on that transition from technology validation to commercial readiness. In February 2026, it formalised a long-term supply agreement with S³, Smart Seismic Solutions, securing a dedicated fleet of seismic sensors for its HOREX® field campaigns.
The arrangement addresses what the company described as a critical operational bottleneck, enabling it to run multiple exploration campaigns in parallel. Viridien, the geoscience data company that entered a strategic partnership and took an investment stake in Mantle8 in 2025, continues to provide access to its GeoVerse geological database and Sercel seismic sensor technology.
The company has also expanded its leadership team ahead of the scale-up: Sylvain Marcant joined as Chief Commercial Officer earlier this year, and Laurence Tiberghien-Portaz, formerly of Rio Tinto, was appointed as HR Director in February 2026. Mantle8’s stated ambition is to have its first exploration drilling campaign ready by 2028 and to reach commercial hydrogen production by 2030.
Whether natural hydrogen can genuinely be extracted at commercial scale remains unproven anywhere in the world. No company has yet drilled a commercially viable reservoir. What the EU grant validates, for now, is the judgment that Mantle8’s Grenoble-rooted geoscience platform is credible enough to receive public R&D investment, and that Europe’s energy transition institutions are paying attention to what might be discovered beneath the continent’s own surface.
