Hydrogen gasoline produced by geological processes beneath Earth’s floor has been touted as a promising clear power supply. A brand new examine gives the primary strong proof that it could possibly be a sensible and commercially viable possibility for decarbonizing the grid.
Hydrogen is an energy-dense gas that produces solely water when burned. However right this moment, the overwhelming majority of commercial hydrogen is manufactured utilizing fossil fuels in an power intensive course of, negating its inexperienced credentials. Whereas there’s hope renewable power may in the future energy the method and supply a dependable supply of inexperienced hydrogen, that expertise continues to be a good distance from business viability.
Just lately although, there was rising pleasure about the potential of huge pure hydrogen reserves saved deep underground. A number of massive deposits have been found and estimates recommend that trillions of tons of the gasoline could possibly be sitting beneath our ft.
Up to now, these estimates have been virtually fully theoretical, based mostly largely on near-surface measurements, proxy knowledge, and extrapolation reasonably than direct observations. Research have additionally sometimes brushed over the complexities of storing and distributing hydrogen gasoline, which must be stored at excessive stress or extraordinarily chilly temperatures.
A brand new examine, revealed in PNAS, companies up the numbers. The authors observe the discharge of pure hydrogen over an 11-year interval from a mine in Canada and conclude the location produces sufficient hydrogen to generate 4.7 million kilowatt-hours of power yearly. That’s sufficient to energy a couple of hundred houses or an industrial facility and suggests essentially the most promising strategy to pure hydrogen could possibly be to make use of it the place you discover it, they are saying.
“We current another imaginative and prescient for the hydrogen financial system that may handle among the present challenges arising from the main target thus far, that has been largely based mostly on transportation of hydrogen over lengthy distances from supply location to markets,” the authors write. “Calculations from this examine web site present that the quantity of domestically generated power has financial worth for each industries and communities positioned on hydrogen-producing rock.”
The brand new examine centered on the Kidd Creek mine close to Timmins, Ontario the place researchers had collected 11 years of hydrogen discharge knowledge from 35 boreholes between two and three kilometers under the floor.
The authors discovered that, on common, these boreholes have been pumping out between 1 and three liters (0.04 to 0.1 cubic ft) of the gasoline per minute. Throughout all of Kidd Creek’s practically 15,000 boreholes, the researchers estimate the location releases greater than 140 tons of hydrogen per yr.
The hydrogen at Kidd Creek is primarily produced via a course of referred to as serpentinization, wherein water reacts with iron-containing minerals deep within the crust. Greater than 70 p.c of the continental crust has the potential for this type of hydrogen technology, the researchers say, suggesting the mine, and its hydrogen output, could also be removed from distinctive.
For the reason that gasoline is already being vented throughout routine mining, capturing it could require comparatively modest funding, the researchers say. And hydrogen is not the one useful resource on provide. Websites that produce hydrogen additionally are inclined to launch methane and helium at predictable charges.
Based mostly on the quantity of hydrogen at Kidd Creek, the researchers estimate the location might be producing 4,200 tons of methane and 140 to 280 tons of helium. The latter could possibly be notably beneficial, given its crucial function in cryogenic applied sciences. With latest provide crunches, additional exacerbated by the Iran conflict, costs have been within the vary of $100,000 per ton.
Capturing the gasoline isn’t all the time easy, the authors notice. Underground microbes can devour it earlier than extraction. It might additionally require important funding after seize to separate the gases.
However many communities sitting on hydrogen-producing rock could have a beneficial renewable power supply simply beneath their ft. And the financial case for exploiting it’s trying more and more strong.
