The GEO Figure: underground, 6,200 billion tons of hydrogen could power us for 200 years

It is under our feet. Somewhere, in the depths of the Earth, 6,200 billion tons of hydrogen are hidden, American scientists believe. In a new study published in Science Advances, they explain that these reserves of hydrogen, contained in underground reservoirs and rocks, could save us from relying on fossil fuels for centuries. The only problem: we have no idea where this hydrogen is.

There are nearly 1.6 trillion barrels of oil left on the planet today. Twenty-six times less than the volume of hydrogen estimated by scientists. But we still need to locate the sources. Most of them are certainly too deep beneath the earth's surface or oceans to be accessible.

Others are so small that extracting hydrogen from them would be a waste of money and time. Despite everything, Geoffrey Ellis, geochemist and lead author of the study, is convinced: there is enough hydrogen for us to move away from fossil fuels for good.

A way to stop carbon emissions for 200 years

In their study, the team of geochemists surrounding Geoffrey Ellis modeled potential sources of hydrogen beneath the Earth's surface. The author of the study maintains to Live Science that 2% of this stock “would provide us with all the hydrogen we need to emit no carbon particles for 200 years.”

To model the pockets of gas and their size, scientists used their knowledge of hydrogen, including the time it takes to produce it underground. “There are at least a dozen natural processes that can generate hydrogen, but most of them only produce very small quantities,” explain the researchers.

With these elements, they managed to estimate the volume that could be locked in reservoirs at depth, subtracting possible, inevitable leaks.

What could all this hydrogen be used for?

Geochemistry specialists only very recently understood that hydrogen could be stored naturally beneath the Earth. The discovery of two reservoirs, in Mali in 2018, and in Albania earlier this year, has reshuffled the cards. As the planet is in danger, fossil resources are drying up and scientists are constantly looking for new ways to produce energy, this discovery could be a game-changer.

Until now, hydrogen has been produced artificially by electrolysis – and sometimes with electricity that is not green at all. Using natural hydrogen would avoid cumbersome processes but would also circumvent the problem of gas storage.

Hydrogen, used to power vehicles, certain industrial processes and to produce electricity, could account for 30% of energy sources in the coming years. Global demand will increase fivefold by 2050, according to the International Energy Agency. Geoffrey Ellis and his teams are racing to determine exactly where to find the sources of supply.