Scientists have discovered that ancient rocks deep underground in Canada naturally emit hydrogen gas, providing new evidence that Earth itself may have significant untapped sources of clean energy.
Researchers from the University of Toronto and the University of Ottawa studied the Canadian Shield, a vast region that contains some of the oldest rock formations on Earth. For the first time, they directly measured the hydrogen escaping from these billion-year-old rocks, tracked how it accumulates over time, and mapped where the gas is concentrated.
The survey results are Proceedings of the National Academy of Sciencescould help determine whether naturally occurring hydrogen, or “white” hydrogen, can be a practical and economical energy source. The study also introduces new strategies for hydrogen exploration that have the potential to support efforts to reduce greenhouse gas emissions and expand clean energy options.
Hydrogen flow measured in an Ontario mine borehole
The researchers collected data from an active mine near Timmins, Ontario. The researchers found that an average of 0.008 tonnes, or approximately 8 kilograms, of hydrogen is released each year from boreholes drilled into the rock. This is equivalent to the weight of a typical car battery. Research suggests the gas could continue to flow for at least 10 years.
When expanded across the approximately 15,000 boreholes on site, the estimated hydrogen production will exceed 140 tonnes per year. The researchers calculated that this amount could generate about 4.7 million kilowatts of energy per year from just one location. This is enough to meet the annual energy needs of over 400 homes.
“The data from this study suggest there is a significant untapped opportunity to access cost-effective domestic energy sources produced from the rocks beneath our feet,” says study lead author Barbara Sherwood-Lorer, a professor in the Department of Earth Sciences in the Faculty of Arts and Sciences at the University of Toronto. “Furthermore, it provides a ‘Made in Canada’ resource that can potentially support local and regional industrial hubs and reduce dependence on imports of hydrocarbon-based fuels.”
Why natural hydrogen is important
Hydrogen already plays a major role in the global economy, with a value of around $135 billion. It is widely used in agriculture and in the production of fertilizers, which are essential to the world’s food production. Hydrogen is also important in methanol production and steel manufacturing.
Currently, most hydrogen is produced using industrial methods that rely on fossil fuels such as oil, natural gas, and coal. These processes require large amounts of energy and release carbon monoxide and CO2. Even “green hydrogen” produced using renewable energy remains expensive and energy-intensive, as well as requiring transportation and storage infrastructure.
However, natural hydrogen has not received much attention. Until recently, most research focused on its role in subsurface microbial ecosystems and its potential importance in astrobiology and space exploration. Scientists lacked direct long-term measurements from real-world sites, so estimates of its energy potential were largely theoretical.
A new study has changed this by documenting sustained hydrogen release over many years.
Ancient rocks naturally produce hydrogen
“Natural hydrogen is produced over time by chemical reactions between underground rocks and the groundwater in those rocks,” says Sherwood-Roller. “Canada is blessed with the presence of rocks and minerals suitable for producing this natural hydrogen in its vast territory, particularly in the Canadian Shield.”
Researchers say Canada may have a unique opportunity to produce cleaner and potentially cheaper hydrogen without relying on hydrocarbons. They also note that similar hydrogen-producing rocks exist in many other countries, suggesting that this approach could eventually be used around the world.
The greatest concentrations of natural hydrogen are found in geological regions already associated with mining activity in Canada. These include Northern Ontario, Quebec, Nunavut, and the Northwest Territories.
“The common link is rocks,” said study co-author Oliver Waugh, an assistant professor in the Department of Earth and Environmental Sciences at the University of Ottawa. “Natural hydrogen is produced in the same rock where Canada’s nickel, copper and diamond deposits are discovered and where exploration is currently underway for critical minerals such as lithium, helium, chromium and cobalt. Co-locating mine resources with hydrogen production and use reduces the need for long transportation routes to market for hydrogen storage and large-scale hydrogen infrastructure development.”
Potential benefits to mining and northern communities
The study’s authors believe natural hydrogen could help reduce both costs and carbon emissions in Canada’s mining sector. Hydrogen produced close to mining operations could provide a regional energy source without the need for large-scale new transportation systems.
The researchers also suggest that northern regions, which often face high fuel transportation costs, could benefit from nearby hydrogen resources. Using locally produced hydrogen has the potential to reduce energy expenditures while reducing dependence on imported fuels.
“There is a global race to increase hydrogen availability, with the aim of decarbonizing the existing hydrogen economy and reducing costs,” says Sherwood Lollar. “We now have a better understanding of the economic viability of this resource, which can be mapped to already known and yet to be discovered hydrogen deposits around the world.”
