Hydrogen is the most abundant element in the universe, and it already plays an important role in many industrial sectors. Used in the manufacture of fertilizers and in certain food processes aimed at extending the shelf life of products, it has a certain advantage: when burned, it does not produce greenhouse gases, which makes it a potentially “clean” and particularly attractive source of energy.
This optimistic observation must, however, be qualified. The majority of hydrogen produced today still comes from fossil fuels, in particular natural gas, a mode of production far from being climate neutral, generating around a billion tonnes of carbon dioxide for only 107 million tonnes of hydrogen. Alternatives exist, such as “green” hydrogen from renewable energies, but their cost remains high, summarizes an article in Smithsonian Magazine.
In this context, a new avenue is attracting growing interest: natural hydrogen, also called “white hydrogen”. This gas is produced spontaneously in the earth’s crust by natural chemical reactions. A recent study conducted in Canada suggests that this resource may be much more accessible and abundant than previously thought.
The researchers drew on more than a decade of data collected from Ontario’s Kidd Creek Mine, one of the deepest and oldest mines in North America. Their results indicate that this site releases enough hydrogen each year to power more than 400 homes. This discovery opens the way to local and potentially profitable energy exploitation.
More broadly, scientists estimate that more than 70% of the continental crust could produce hydrogen. The mines, already present and operational, could thus become privileged access points to this resource. According to the authors of the study, this is a still largely untapped opportunity for producing domestic energy at lower cost.
The first empirical data
Two main mechanisms explain the formation of this natural hydrogen. The first occurs when water reacts with rocks rich in iron or magnesium, releasing hydrogen. The second is linked to the disintegration of radioactive elements, which splits water molecules: processes at work for millions of years in the depths of the earth.
To obtain concrete data, the researchers analyzed groundwater from 35 boreholes located between 2 and 3 kilometers below the surface. They measured the amount of hydrogen dissolved in this water and found a significant average production. By extrapolating these results to all of the approximately 15,000 boreholes on the site, they estimate that the mine could release more than 150 million tonnes of hydrogen per year.
This estimate is based on rare and valuable empirical data. Until now, most assessments of natural hydrogen have been based on theoretical models. Having measurements over such a long period constitutes a major step forward in better understanding the real potential of this resource.
The geological context plays a key role in the presence or absence of this hydrogen. The Kidd Creek mine is located in the Canadian Shield, a very ancient rock formation rich in metals, conditions which favor the production of hydrogen. This proximity between mining resources and energy production could limit the need for transport, storage and heavy infrastructure.
Today, the exploitation of natural hydrogen remains marginal. Only one site, in Mali, actively produces this gas – discovered by chance in the 1980s – and supplies a local village with energy. But with the growing interest of manufacturers and start-ups in this resource, white hydrogen could soon become a major new player in the energy transition.
