Trillions of Tons of Underground Hydrogen Could Power Earth for Over 1,000 Years: Study

Geologic hydrogen could be a low-carbon primary energy resource.

A recent study has suggested that trillions of tons of hydrogen gas could be buried beneath the Earth’s surface. Led by a petroleum geochemist at the U.S. Geological Survey (USGS), the study suggests that Earth could hold around 6.2 trillion tons (5.6 trillion metric tons) of hydrogen in rocks and underground reservoirs. Researchers claimed that just a fraction of this massive amount of hydrogen gas could reduce humans’ dependency on fossil fuels for almost 20 decades. Formed during natural geochemical processes on Earth, geologic hydrogen could fulfill multiple needs. So far, it has been discovered in just a few places, including Albania and Mali.

Reserves could stretch all around globe

However, a recent study claims that these reserves could stretch all around the globe. Although, most of the hydrogen is expected to be too deep or too far offshore to be accessed.

Some of the reserves are probably too small to extract in a way that makes economic sense, the researchers suspect. However, the results indicate there’s more than enough hydrogen to go around, even with those limitations, Geoffrey Ellis, a petroleum geochemist at the U.S. Geological Survey (USGS) and lead author of the new study, told Live Science. Researchers claimed that geologic hydrogen could be a low-carbon primary energy resource; however, the magnitude of Earth’s subsurface endowment has not yet been assessed. Knowledge of the occurrence and behavior of natural hydrogen on Earth has been combined with information from geologic analogs to construct a mass balance model to predict the resource potential.

5.6 × 10⁶ metric tonnes of hydrogen

The study published in Science Advances predicts a wide range of values for the potential in-place hydrogen resource (10³ to 10¹⁰ million metric tons (Mt)) with the most probable value of ~5.6 × 10⁶ Mt. Although most of this hydrogen is likely to be impractical to recover, a small fraction or two percent (e.g., 1 × 10⁵ Mt) would supply the projected hydrogen needed to reach net-zero carbon emissions for ~200 years.

This amount of hydrogen contains more energy (~1.4 × 10¹⁶ MJ) than all proven natural gas reserves on Earth (~8.4 × 10¹⁵ MJ). Study results demonstrate that further research into understanding the potential for geologic hydrogen resources is merited, according to the study.

Researchers developed a model to estimate the size of these reservoirs globally, combining a prior understanding of how hydrogen occurs and behaves with geologic data. This model suggests there may be as much as 5.6 × 10⁶ metric tonnes (that’s the equivalent weight of 3.7 million cars or 1.56 billion flamingos) of hydrogen hiding beneath the surface.

Prof Bill McGuire, an Earth scientist at University College London (UCL), told BBC Science Focus that to suck up hydrogen at a scale required to make a contribution to bringing down emissions and tackling the climate emergency would require an enormous global initiative for which we simply don’t have time.