Deep beneath the peaks of the Alps and Pyrenees, scientists have discovered something unexpected: a natural hydrogen reserve that could quietly reshape the future of clean energy. Researchers at the University of Lausanne and the GFZ Helmholtz Center for Geosciences have found that mountain ranges formed by colliding tectonic plates create the precise conditions for hydrogen gas to accumulate underground—and that the very forces carving these mountains play a crucial role in either building up or breaking down these potential energy stores.
The process, called serpentinization, occurs when mantle rocks are pushed upward toward the Earth's surface over millions of years. As these rocks rise and cool to just the right temperature, they react with groundwater, releasing hydrogen gas that can collect in porous rock layers beneath the surface. Think of it as the Earth itself exhaling a clean fuel.
What makes this new research particularly striking is the finding that erosion wields a paradoxical influence over these hydrogen deposits. Slow, measured erosion helps hoist mantle rocks closer to the surface, creating ideal conditions for hydrogen generation. But erosion that runs too fast or too intense can crush potential reservoirs or disrupt the delicate temperature balance required for the chemical reactions to occur. "Unexpectedly, erosion turns out to be a key and ambivalent factor in natural hydrogen production," said lead author Frank Zwaan, now at the University of Lausanne.
The researchers used advanced numerical modeling to compare several mountain ranges, revealing that the Pyrenees and the Alps show particularly promising conditions for natural hydrogen accumulation. The key lies in the regions' geological history—specifically, how long the area experienced tectonic extension before the mountains began rising. The longer this stretching phase, the more favorable the conditions for hydrogen generation become.
Small-scale natural hydrogen extraction is already happening today in Mali, proving the concept works. The question researchers now face is whether much larger accumulations exist elsewhere, including in European backyards. "We already know that Earth produces large amounts of hydrogen," Zwaan explained. "The key question now is whether large-scale hydrogen accumulations can be found, because very specific conditions must be met, with all key elements in place at the right time."
For an energy system desperate for alternatives to fossil fuels, hydrogen's appeal is clear: it can power vehicles and help decarbonize industries that are difficult to electrify directly. The challenge has always been producing it cleanly and affordably. If natural deposits can be tapped, the calculus changes entirely. The mountains, it seems, may have been hiding something valuable all along.