Geologists are signalling the start of a new energy “gold rush” for a previously neglected carbon-free resource — hydrogen generated naturally within Earth. As much as 5tn tonnes of hydrogen exists in underground reservoirs worldwide, according to an unpublished study by the US Geological Survey.
Previewing the results at the American Association for the Advancement of Science annual meeting in Denver, project leader Geoffrey Ellis said: “Most hydrogen is likely inaccessible, but a few per cent recovery would still supply all projected demand — 500mn tonnes a year — for hundreds of years.”
The demand for hydrogen as a fuel and industrial raw material, particularly to make ammonia for fertiliser production, has been mainly met so far by chemically reforming gas that is made up largely of methane, known as “blue hydrogen” when the carbon emissions are captured or “grey hydrogen” when they are not. A smaller amount is made by splitting water through electrolysis using renewable energy sources, known as “green hydrogen”.
But Mengli Zhang of the Colorado School of Mines said tapping natural hydrogen — also known as geologic or gold hydrogen — would be cleaner and cheaper than blue or green hydrogen. “A gold rush for gold hydrogen is coming,” she told the conference.
The prospect is beginning to attract interest from investors. US start-up Koloma raised $91mn last year from funds including Bill Gates’s Breakthrough Energy Ventures.
“Geologic hydrogen represents an extraordinary opportunity to produce clean hydrogen in a way that is not only low carbon, but also low land footprint, low water footprint and low energy consumption,” said Paul Harraka, Koloma’s chief business officer.
US company Natural Hydrogen Energy has drilled an exploratory well in Nebraska. “It will take a couple of years to ramp up to commercial production,” said Viacheslav Zgonnik, chief executive. “We are doing everything we can to get there faster.”
Previous scientific opinion held that little pure hydrogen was likely to exist near Earth’s surface because it would be consumed by subterranean microbes or destroyed in geochemical processes.
But geologists now believe hydrogen is generated in large quantities when certain iron-rich minerals react with water, Alexis Templeton of the University of Colorado, Boulder, told the AAAS conference.
Hydrogen requires different geological conditions from oil and natural gasfields. “We haven’t looked for hydrogen resources in the right places with the right tools,” said Ellis.
Geologists are now finding natural hydrogen reserves around the world. This month researchers reported that more than 200 tonnes of hydrogen a year were flowing from the Bulqizë chromite mine in Albania.
The village of Bourakébougou in Mali is often seen as the birthplace of natural hydrogen extraction. Since 2012, almost pure hydrogen has flowed from a borehole there with no diminution of pressure, giving villagers their first electricity supply.
Ellis said the Bourakébougou gas well may have inspired a hydrogen rush comparable with the birth of the petroleum industry in 1859, when Edwin Drake drove a pipe into the ground at Titusville, Pennsylvania and struck
