Mantle8, a France-based natural hydrogen exploration company developing proprietary subsurface exploration technologies, announced a €31 million Series A funding round led by Sandwater. The round included participation from Breakthrough Energy Ventures, Ecotechnologies 2 fund managed by Bpifrance on behalf of the French government, IP Group, Wind Capital, and Calderion.
The funding will support a global exploration and drilling campaign focused on identifying commercially viable reservoirs of high-purity natural hydrogen.
Scaling Exploration And Drilling Operations
Mantle8 plans to deploy its proprietary exploration technology stack across multiple international sites to identify and rank high-potential natural hydrogen reservoirs. Selected locations will undergo drilling operations to evaluate hydrogen purity, reservoir quality, and production potential.
The company aims to accelerate development of low-cost, low-carbon hydrogen resources that could contribute to Europe’s energy independence and broader industrial decarbonization goals.
Proprietary Technology For Natural Hydrogen Discovery
Mantle8’s platform is designed to reduce exploration risk and improve the commercial viability of natural hydrogen extraction. According to company projections, production costs could reach as low as €0.80 per kilogram, significantly below many existing clean hydrogen alternatives.
“This raise reflects the growing conviction among leading clean tech investors that natural hydrogen is a resource worth pursuing at scale,” said Emmanuel Masini, Founder and CEO of Mantle8. “The existence of natural hydrogen is a well-established scientific fact; the challenge has been finding free gas accumulations of high-purity hydrogen that are commercially viable.”
“The next steps are to identify the prospects in our pipeline that meet our commercial hurdles and drill them,” Masini added.
Investor Support For Energy Transition Technologies
Investors highlighted the strategic importance of natural hydrogen within Europe’s clean energy and energy sovereignty initiatives.
Building Commercial-Scale Natural Hydrogen Production
The Series A follows a period of operational growth for Mantle8. In 2025, the company completed the world’s first 4D imaging of an active underground natural hydrogen system using its HOREX® technology at the Hydrogeco project in the French Pyrenees. Earlier this year, Mantle8 also secured a €2.06 million grant from the EU Just Transition Fund to industrialize its exploration technologies.
The latest round brings Mantle8’s total funding to €37 million.
“With this backing, we will work alongside industrial partners globally to move from exploration through to commercial development,” said Bart Markus, Chairman of Mantle8.