A €2.06 million grant from the EU provides the Grenoble-based deep-tech startup Mantle8 with non-dilutive financing to industrialize its four-component technology platform, advancing towards its first commercial drilling campaign.
Fourteen months after closing a €3.4 million seed round supported by Bill Gates’ Breakthrough Energy Ventures and Kiko Ventures, Mantle8 has acquired additional capital from the EU. The Grenoble-based natural hydrogen exploration company received €2.06 million from the EU’s Just Transition Fund, via the FEDER/FSE+/JTF 2021–2027 programme managed by the Auvergne-Rhône-Alpes region. The non-dilutive grant entails no equity exchange.
This grant is part of a broader €4.84 million R&D programme running through 2028, bringing Mantle8’s total funding to around €5.46 million. Activities under this programme will focus on Grenoble and the Auvergne-Rhône-Alpes region, leveraging the area’s geoscience expertise.
Mantle8’s technology platform comprises four proprietary systems. GeoLogix® is a prospect generation algorithm that analyzes geological data to identify locations suitable for natural hydrogen production, including the presence of source rocks, active generation zones, and viable reservoir structures.
HOREX® is the company’s multiphysics imaging system, deploying passive seismic sensors across field sites to create a four-dimensional view of underground hydrogen-generating systems. APoGeH® evaluates potential hydrogen yield by analyzing liquid, gas, and rock samples. Simul8, a digital twin modeling engine, integrates the other three systems for comprehensive hydrogen system simulations.
EU funding supports all four systems. HOREX® development continues at Mantle8’s Hydrogeco prospect in the French Pyrénées, where in October 2025, the company created the world’s first three-dimensional images of an active underground hydrogen system.
An APoGeH® geochemistry lab will be established at Mantle8’s Grenoble headquarters, eliminating reliance on external facilities for sample analysis. GeoLogix® will be upgraded for more automation and higher-resolution imaging. PhD researchers will collaborate with university partners and Mantle8’s scientific advisory board.
The grant does not directly fund exploration drilling. Its goal is to industrialize Mantle8’s technology stack, enhancing system efficiency and precision for faster, larger-scale deployment. The aim is to minimize time and cost between identifying potential hydrogen reservoirs and justifying drilling decisions.
Mantle8 is swiftly transitioning from technology validation to commercial readiness. In February 2026, it established a long-term supply agreement with S³, Smart Seismic Solutions, securing a dedicated fleet of seismic sensors for HOREX® campaigns.
This addresses a critical operational bottleneck, allowing multiple exploration campaigns to run concurrently. Viridien, a geoscience data firm, partnered strategically with Mantle8 in 2025 and continues to provide access to its GeoVerse geological database and Sercel seismic sensor technology.
The leadership team has expanded as the company scales up: Sylvain Marcant became Chief Commercial Officer, and Laurence Tiberghien-Portaz, formerly with Rio Tinto, was appointed HR Director in February 2026. Mantle8 aims to commence exploration drilling by 2028 and achieve commercial hydrogen production by 2030.
The commercial feasibility of extracting natural hydrogen remains unproven globally. No company has yet successfully drilled a commercially viable reservoir. The EU grant underscores disapproval in Mantle8’s Grenoble-based geoscience platform and highlights European energy transition institutions’ interest in potential underground findings.