Since their formation billions of years ago, the oldest parts of the Earth’s continental rocks have generated natural hydrogen in massive amounts. Some of this hydrogen may have accumulated within accessible traps and reservoirs under the Earth’s surface. This store has the potential to contribute to the global hydrogen economy for hundreds of years.
This has been demonstrated by the production of near-pure hydrogen from a single gas field in Mali, attracting the attention of governments in the United States, Canada, Australia, the United Kingdom and Europe.
There is also interest from major venture capital investors and international resource companies. By the end of 2023, 40 companies were exploring natural hydrogen globally. That has likely doubled since 2024.
Read more: Why green hydrogen — but not grey — could help solve climate change
Hydrogen as a resource
Hydrogen resources have long been a multi-billion-dollar market, even before recent interest in hydrogen as a contributor to the green energy transition. The environments and conditions that result in natural hydrogen accumulation occur globally. But one of the barriers to investment in many jurisdictions is regulatory, as hydrogen had not previously been considered as a resource.
Natural hydrogen can be used to decarbonize hard-to-abate but globally critical industries. Industries that use hydrogen include fuel refining (about 44 per cent), ammonia and fertilizer production for food sustainability (about 34 per cent), and steel manufacturing (about five per cent).
According to a recent British government policy briefing document, addressing this requires governments to include hydrogen as a listed natural resource. Future uses for hydrogen may include long-distance transportation and contributions to the decarbonization of the mining industry.
High carbon footprint
Most of the hydrogen used today is produced from fossil fuels. Because of this, hydrogen production contributes about 2.5 per cent of global carbon dioxide emissions. Efforts to produce low-carbon (green) hydrogen from renewable electricity and carbon capture and storage technologies remain expensive.
Natural hydrogen has a carbon footprint comparable to or below that of green hydrogen. The two will likely be complementary, but estimates are uncertain as natural hydrogen is as yet an unproven resource.
Developing strategies could determine whether hydrogen from any source is an economically viable resource. For natural hydrogen, exploration strategies have to be developed to find and extract natural deposits of hydrogen at an economically feasible cost. This also needs incentives that include natural hydrogen in exploration or production licenses.
Read more: New plan shows Australia's hydrogen dream is still alive. But are we betting on the right projects?
Hydrogen and helium
The U.S. Geological Survey recently estimated there’s enough accessible natural hydrogen to supply global hydrogen demand for about 200 years.
Hydrogen forms in the Earth’s crust through two natural geological processes: chemical reactions between natural groundwaters and iron-rich minerals and water radiolysis. Water molecules are broken by natural background radioactivity in rocks releasing hydrogen — and helium, a valuable element included in Canada’s Critical Minerals Strategy — as a byproduct.
The search for helium began in Canada in the 1920s, but it is only recently that systematic commercial exploration for helium has restarted. By the 1980s, systematic studies of natural hydrogen began in Canada, Finland and parts of Africa as part of research on subsurface microbial life.
Renewed interest
An unusual coincidence sparked the current global interest in hydrogen. An accidental discovery of the small natural hydrogen gas field in Mali coincided with the publication of extensive historical data from the former Soviet Union, drawing attention to hydrogen’s immense potential as a clean power resource. Australia, France and the U.S. were among the first countries to re-investigate historical natural hydrogen.
Natural hydrogen and helium systems have similarities to petroleum systems, requiring a source rock, a migration pathway and accumulation in a reservoir. The infrastructure for natural hydrogen wells would be comparable to hydrocarbon wells, albeit with changes in well completion and drilling methods.
The footprint of a natural hydrogen production project would take up much less space to deliver the same amount of energy compared to a green hydrogen production facility, which requires solar or wind farms and electrolyzers.
Similarly, natural hydrogen projects do not need to draw on surface water resources, which are scarce in many parts of the world.
Future policies
Some jurisdictions lack policies regulating hydrogen exploration. In others, regulation falls under existing mining or hydrocarbon policies. The lack of clear regulations in areas with high potential for natural hydrogen exploration — such as the U.S., Canada, India and parts of Africa and Europe — is a major obstacle for exploration.
An absence of regulation slows down exploration and land acquisition, and prevents the decision-making required for developing infrastructure. And critically, it means that no community consultations are undertaken to ensure the social acceptance essential for the success of such projects.
A project in South Australia demonstrates what legislation can accomplish. Once regulation of natural hydrogen exploration and capture was implemented, the government received dozens of applications from companies interested in natural hydrogen exploration.
The appetite for exploration is clearly there, but policy and regulatory solutions are required. New exploration projects will provide critical new data to understand natural hydrogen’s potential to provide green energy.
Omid Haeri Ardakani has received funding from Natural Resources Canada (NRCan).
Barbara Sherwood Lollar receives funding from the Natural Sciences and Engineering Research Council of Canada and the Nuclear Waste Management Organization.
Chris Ballentine is founder of and owns shares in Snowfox Discovery Ltd, a hydrogen exploration company. He receives research funding from the Natural Environment Research Council (U.K.) and the National Science Foundation (U.S.), in a joint grant, as well as the Canadian Nuclear Waste Management Organization and the Canadian Institute For Advanced Research.
This article was originally published on The Conversation. Read the original article.
