Mantle8, a natural hydrogen exploration company, has been granted two investigation permits by Spain’s Dirección General de Política Energética y Minas. The permits, Aralar I and Aralar II, cover approximately 960 km2 across Navarra and the Basque Country. The permits authorize noninvasive studies for natural hydrogen and helium, providing Mantle8 with the option to progress to a full exploration license.
The permit area lies on the southern flank of the Pyrenees, with a similar geology to what Mantle8 is evaluating through its Comminges permit on the French side of the mountain range. France awarded an exclusive 5-year exploration permit for natural hydrogen and helium to G&OL SAS, a wholly owned subsidiary of Mantle8, in April. That permit covers 739 km2 across the departments (administrative regions) of Haute-Garonne and Hautes-Pyrénées in the French Pyrenees.
Drawing on its deep knowledge of Pyrenean geology, Mantle8 said it plans to conduct noninvasive exploration across the permit area. The data will be processed using Mantle8’s proprietary natural hydrogen technology stack to evaluate the area’s potential for natural hydrogen accumulations.
“Navarra and the Basque Country offer a rare combination of favorable geology supported by established infrastructure in a region with strong industrial off-take potential,” said Emmanuel Masini, founder and CEO of Mantle8. “Our geological understanding of this region and its hydrogen potential is already very strong, and we’re excited to get into the field to expand our knowledge base.”
Natural hydrogen is produced by ongoing geological processes such as serpentinization, where water reacts with iron-rich rocks deep underground. Unlike manufactured hydrogen, it requires no electrolysis or fossil fuel inputs, offering a low-carbon source of hydrogen at a fraction of the energy intensity of current production methods.
The permits reflect a broader shift across Europe as governments look to secure sovereign energy sources for sectors where electrification is not viable. With demand for low-carbon hydrogen in heavy industry, transport, and power generation continuing to outpace supply, natural hydrogen is seen as a domestic alternative that does not depend on imported feedstocks or large-scale renewable electricity infrastructure.
“Natural hydrogen has the potential to become a strategic, sovereign, and clean resource for Europe,” Masini said. “However, regulatory gaps are slowing the pace of development. The Spanish regulators have done well to adapt existing hydrocarbon regulations to include hydrogen, but there’s still work to do. We welcome clearer regulatory frameworks across Europe and will prioritize those where we see the best opportunity to unlock this incredible resource.”
The Spanish permits come at a period of growth for Mantle8. The company closed a €31 million Series A financing round—the largest raised by a natural hydrogen exploration company in 2026—received €2.17 million in grant support from the French government for the development of its technology stack, and secured a 5-year exploration permit in the French Pyrenees. The company said it is actively expanding its global exploration program with additional permits expected to be awarded in the coming months.
