Mantle8 Raises €31 Million in Series A Funding to Prove Commercial Viability of Natural Hydrogen Production

Mantle8, unearthing natural hydrogen, led by Emmanuel Masini, has raised €31M in Series A funding led by Sandwater and includes Breakthrough Energy Ventures, Ecotechnologies 2 fund managed on behalf of the French government by Bpifrance, IP Group, Wind Capital, and Calderion (an Audacia-backed investment platform).

This capital will fund the next two years of advanced natural hydrogen exploration and drilling. Mantle8 will deploy its technology platform to identify and rank promising hydrogen reservoirs across its global pipeline.

Selected sites will then be drilled to confirm hydrogen presence and assess volume, purity, and reservoir quality for potential large-scale production.

Hydrogen is expected to play a key role in a decarbonised industrial system, but its impact depends on cost and sourcing. Mantle8’s technology reduces exploration risk and cost for natural hydrogen, with models projecting production as low as €0.80/kg.

By enabling faster identification of viable reservoirs and partnering for drilling and development, the approach aims to scale quickly and reshape hydrogen supply economics for Europe and beyond.

“This raise reflects growing conviction that natural hydrogen can be pursued at scale,” said Emmanuel Masini. “The challenge has been finding high-purity, commercially viable accumulations, and we’ve built a proprietary technology stack to address that. The next step is to identify and drill the most promising prospects in our pipeline.”

“We back exceptional founders with the technical and operational strength to solve critical challenges,” said Tom Even Mortensen. “Mantle8 has built proprietary exploration technology, validated it in the field, and is now moving toward commercialization. Natural hydrogen sits at the intersection of energy transition and resource discovery, with potential to create a new clean energy source for Europe’s energy sovereignty.”

“Geologic hydrogen is a major emerging energy development with potential to contribute to the global energy mix,” said Carmichael Roberts. “Mantle8 has made strong progress with a geology-driven exploration approach and is working toward identifying the first commercially viable high-purity hydrogen reservoir.”

“Natural hydrogen represents a strategic opportunity for France and Europe,” said Alexandre Wagner. “Mantle8 combines proprietary exploration technology with a clear path to commercialization, supporting sovereign low-carbon energy solutions that could be developed within this decade.”

Mantle8’s Series A builds on strong momentum, including a €3.4M seed round led by Breakthrough Energy Ventures and the world’s first 4D imaging of an active underground natural hydrogen system using HOREX® in the French Pyrenees.

Earlier this year, the company also secured a €2.06M EU Just Transition Fund grant to scale and industrialize its core exploration technologies.

This investment brings Mantle8’s total funding to €37M (US$44M).

“With this backing, we will work with industrial partners to move from exploration to commercial development,” said Bart Markus. “The next two years will focus on proving that the identified hydrogen systems can deliver sustained, commercially viable flow.”