Natural hydrogen could be found beneath the Alps and Pyrenees, according to new research that suggests the very processes that build mountain ranges may also generate and trap the gas deep underground. The findings, published in the Journal of Geophysical Research: Solid Earth, open up the possibility that Europe’s most famous mountain chains could become sources of a low-carbon fuel already being sought by more than forty companies worldwide.
The untapped potential of natural hydrogen
Hydrogen is expected to play a central role in the transition away from fossil fuels, particularly in hard-to-decarbonise sectors such as chemical production, shipping and steelmaking. But the synthetic hydrogen produced today—whether by splitting water with electricity or reforming natural gas—is both energy-intensive and expensive. Natural hydrogen, sometimes called “white,” “gold,” or “geologic” hydrogen, forms underground through geological reactions and could be extracted directly from reservoirs, offering a potentially cheaper and lower-carbon alternative. Production costs have been estimated as low as $0.14 per kilogram of H2, and commercially produced hydrogen in Mali already sells for around $0.50/kg. Modelling suggests vast quantities exist globally, enough to meet human demand for thousands of years. Because it produces only water vapour when burned, natural hydrogen also carries a near-zero carbon footprint, provided co-produced hydrocarbons such as methane are not released or flared during extraction.
How mountain-building creates hydrogen
The research, led by scientists using plate tectonic simulations, examined three mountain ranges: the Pyrenees, the Alps, and the Baetic Mountains in southern Spain. The simulations showed that the Alps and Pyrenees are strong candidates for natural hydrogen exploration, while the Baetics are not. The key lies in the speed and style of mountain building.
When tectonic plates collide, deep mantle rocks are thrust toward the surface. In the Alps and Pyrenees, the models indicated that this uplift occurred at just the right speed for the rocks to react with water that circulated along faults and fractures. The chemical reaction—known as serpentinization—occurs when water interacts with iron-rich minerals such as olivine and pyroxene, releasing molecular hydrogen. The colder temperatures found in mountain ranges, combined with the abundant water flow along fault lines, create particularly favourable conditions. Simulations suggest that mountain formation can generate up to twenty times more hydrogen than continent rifting environments.
Once released, the hydrogen gas migrated upward until it encountered porous reservoir rocks—layers of sandstone or fractured limestone that could trap the gas in the same way conventional oil and gas reservoirs work. The Alps and Pyrenees, the researchers concluded, possess both the source rocks that produce hydrogen and the cap rocks that keep it contained.
The Baetic Mountains, by contrast, experienced faster rates of uplift and erosion. This meant there was insufficient time for large volumes of hydrogen to be generated, and the erosion likely removed any potential reservoir rocks that might have accumulated the gas. The findings underline that not every mountain range is a hydrogen prospect; the timing of tectonic processes is critical.
Other geological mechanisms can also produce natural hydrogen, including radiolysis—where natural radiation from radioactive elements splits water molecules—and deep mantle degassing. But serpentinization, driven by the exposure of mantle rocks during mountain building, is considered the primary process at work in the Alps and Pyrenees.
From discovery to real-world applications
The potential applications of natural hydrogen are wide. If exploited, it could supply the chemical industry, power ships, and fuel steelmaking without the carbon emissions associated with today’s hydrogen production. Because the extraction would use existing oil and gas infrastructure—drills, pipelines, processing plants—the transition from fossil fuels to natural hydrogen could be faster and cheaper than building entirely new systems from scratch. Moreover, the environmental disruption from drilling for hydrogen is expected to be far lower than for fossil fuels, as no fracking or deep-sea drilling is required.
Yet challenges remain. Natural hydrogen is rarely found in pure form; it is often mixed with nitrogen, methane, or helium. When methane is co-produced, its release or flaring during extraction can negate the climate benefits, so purification adds cost and complexity. Hydrogen’s small molecular size also makes it prone to leaking from wellheads, pipelines, and storage tanks—leaks that have indirect warming effects on the atmosphere. Accurate detection and mapping of reserves are still in early stages, and existing geophysical tools must be adapted to differentiate hydrogen from other subsurface gases. Finding large, permeable reservoirs with economically viable concentrations remains a hurdle, and the time from discovery to production can stretch fifteen to seventeen years.
Despite these obstacles, global interest is surging. By the end of 2023, more than forty companies were exploring for natural hydrogen in Australia, the United States, Spain, France, Albania, Colombia, South Korea, and Canada. Notable discoveries include the Lorraine basin in France, estimated to hold around ninety-two million tons of hydrogen; the village of Bourakebougou in Mali, which has been generating electricity from a single natural hydrogen well since 2012—the world’s first and only economically successful operation; ancient rocks in the Canadian Shield that continue to produce hydrogen; and high concentrations found in South Australia. Key players in the field include Koloma, Gold Hydrogen, HyTerra, Hydroma, 45-8 ENERGY, Snowfox Discovery, Mantle8, and Rio Tinto.
The United Kingdom is also engaging with the emerging resource. The government has committed £1 billion through the Net Zero Innovation Portfolio to support hydrogen research, and UK Research and Innovation is funding work across the entire hydrogen value chain. The Royal Society has identified Scotland and Cornwall as potential natural hydrogen hotspots, and a report by the British Geological Survey mapped geological terranes in the UK with “potential” or “limited potential” for natural hydrogen, although no confirmed accumulations have yet been discovered. The UK has set ambitious targets for hydrogen production and is developing business models for transport and storage infrastructure.
The same plate tectonic simulation methods used to assess the Alps and Pyrenees can now be applied to other mountain ranges around the world, helping to identify further potential sources of natural hydrogen.
