Could natural hydrogen from underground help the UK get to net zero?

In recent years, the discovery of underground reserves of hydrogen gas has spurred a worldwide search for what could prove to be a significant new source of zero-carbon fuel, but so far, prospectors have largely skipped the UK.

According to a briefing on natural hydrogen produced by the Royal Society, that is not due to geology. “There are rocks that certainly would fit within having the potential to produce hydrogen, but the investigations haven’t been done,” says Barbara Sherwood Lollar at the University of Toronto in Canada, who led work on the report.

It also isn’t down to lack of interest in hydrogen. The UK’s latest hydrogen strategy says that hydrogen produced via low-carbon methods “has a critical role in helping to achieve our Clean Energy Superpower Mission”, including as a source of power for heavy industry, transportation and long-duration energy storage. Natural hydrogen, however, isn’t mentioned as a potential source.

Novelty is one reason for this, says Philip Ball, a researcher at Keele University, UK, who contributed to the report and is an investor in natural hydrogen companies. “Nobody is paying attention, basically. No one is regulating this new subject. No one understands it.”

That could be starting to shift. Ball says several companies have purchased rights to explore for hydrogen in the UK, for instance around Devon in the southwest, and there is research going on at several universities. The British Geological Survey is also now at work on a more detailed study based about the potential for natural hydrogen in the UK. The country’s rich history of geological study means there is plenty of data to draw from.

And there is reason to think there might be something to find. According to the report, the UK has ample amounts of the rocks known to generate natural hydrogen, such as the iron-rich ultramafic rocks that generate the gas when they react with water. These rocks occur in regions like the Lizard Peninsula in Cornwall and the Shetland Islands in Scotland. Rocks in other areas like the North Pennines may split water molecules with natural radioactivity to produce hydrogen.

“It’s most definitely going to be in the UK,” says Ball. “Whether it’s in economic quantities is the question.”

If there is hydrogen to be found in the UK, no one should expect “some bonanza of an endlessly renewable commodity”, says Sherwood Lollar. She says one broader purpose of the report was to offer a “course correction” for some of the more dubious claims that have been made about natural hydrogen, such as the idea that large amounts of hydrogen are rising from deep in Earth’s mantle or even core.

More conservative estimates of how much hydrogen may be generated in the crust are large enough: the researchers estimate around 1 million tonnes of hydrogen seep out of the crust each year, which over time could produce some large accumulations. “Even if we can capture a small proportion of this, it could still be an important contributor to the hydrogen economy,” says Sherwood Lollar.

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