CLIMATE · CLEAN ENERGY
Natural hydrogen and new ways of producing it inside rock are drawing explorers underground. The opportunity is substantial, but so are the unanswered questions.
A new energy search is moving below the surface. Prospectors are looking for naturally occurring hydrogen, while engineers are testing whether useful volumes of the gas can be created inside rock formations that contain the right ingredients.
The attraction is easy to understand. Hydrogen can power heavy trucks, aircraft and industrial processes such as steelmaking. Using it does not directly release carbon dioxide, making the gas a possible tool for sectors that are difficult to electrify.
Why Today’s Hydrogen Is Still Expensive
Yet most hydrogen is not clean today. Producers generally extract it from natural gas, and the resulting material is used mainly in petroleum refining, fertilizer production and chemical manufacturing. The process can carry a large carbon footprint before the hydrogen ever reaches a customer.
For years, the cleaner contest appeared to have two leading options. One uses renewable electricity in electrolyzers to split water. The other keeps conventional fossil-based production but captures some of its carbon emissions. Both routes have struggled to expand because their costs remain high.
That possibility has intensified interest in finding a third route. Instead of building an entirely new aboveground production chain, developers hope geological reactions can supply hydrogen continuously, sometimes from locations already familiar to drilling companies. The concept resembles mineral exploration more than a conventional renewable project: teams interpret rock chemistry, drill test wells, sample gases and search for structures capable of holding a molecule that readily escapes.
Geologic hydrogen offers a different possibility: let underground chemistry do more of the work. Natural hydrogen has been reported on five continents, from Africa to North America and Australia. If drillers can locate concentrated deposits and recover them economically, the resource could open a cheaper supply route.
Where the Gas May Be Waiting
The US Geological Survey has mapped areas where natural hydrogen appears most likely. One prominent zone follows the Midcontinent Rift from Kansas toward Michigan. Roughly a billion years ago, Earth’s crust stretched there and molten material rose through the opening, leaving extensive iron-rich rock behind.
When water interacts with some iron-bearing minerals, the reaction can generate hydrogen. That basic chemistry is sending companies into the region. Australian firm HyTerra is exploring in Nebraska and Kansas and has reported gas samples containing hydrogen concentrations as high as 96%. Koloma, which has raised more than $400 million, is also prospecting there.
Discovery alone does not guarantee a commercial field. Hydrogen molecules are exceptionally small and light, allowing the gas to escape through tiny fractures that would hold other fuels. Explorers must determine how quickly natural processes replenish hydrogen, where it becomes trapped and whether wells can collect enough of it at a workable price.
Evidence from a mine in northern Ontario gives researchers a reason to keep looking. Measurements from several dozen boreholes found that each released about eight kilograms of hydrogen annually. The site contains more than 14,000 boreholes, suggesting that modest flows could become meaningful when collected across a large area.
Stimulating Hydrogen Underground
Some developers do not plan to wait for a ready-made reservoir. Stimulated geologic hydrogen starts with rock that can produce the gas but lacks a useful accumulation. Operators inject water, add catalysts or alter underground conditions so the desired reaction proceeds faster.
Texas-based Vema Hydrogen is drilling wells and introducing water and catalysts to subsurface formations. It is testing the approach in Quebec and says it aims to begin full-scale production in 2028. Eden GeoPower is pursuing another piece of the puzzle, using electricity to create fracture networks that give water more pathways through the rock. A similar technique could support enhanced geothermal systems.
The field still has to answer questions far beyond drilling. Hydrogen is difficult to transport and store: as a gas it occupies substantial space, while liquefying it demands extremely low temperatures. New wells will also need credible measurements of output, leakage, environmental effects and long-term production.
Underground hydrogen is therefore not a finished climate solution. It is a collection of promising clues, experimental wells and geological theories moving toward commercial tests. If companies can control the chemistry, capture the gas and deliver it affordably, the next chapter of clean hydrogen may begin beneath our feet.
