Feature: US aims to unlock massive underground hydrogen resources with right chemical reaction

The US' underground hydrogen deposits could be "stimulated" on demand if a US Department of Energy research team can figure out the right catalyst.

The premise is that when iron and water react, they make hydrogen. And while large hydrogen deposits may be scarce, iron is abundant, said Doug Wicks, a program director at the DOE's Advanced Research Projects Agency.

According to Wicks' rough calculation, the US has enough iron within five kilometers underground to make 176 trillion tons of hydrogen gas.

"If I'm less than 1% successful, that's enough hydrogen to power the entire US economy for 1,000 years," he said in an interview.

Today, US refineries, steel mills and fertilizer plants source hydrogen from industrial plants, which almost all use natural gas as a feedstock. But federal subsidies for "clean" hydrogen and carbon capture are slowly encouraging some operators to sequester their CO2 emissions or switch to zero-emission electrolysis.

US policymakers are trying to promote hydrogen as a cleaner fuel for the transportation and power sectors, though industry members say the industrial gas is nowhere near price-competitive with fossil fuels.

Some companies believe clean hydrogen could become economical if it could be drilled out of the ground, like natural gas. The US Geological Survey has identified potential hydrogen accumulations in the Four Corners states of Arizona, Utah, New Mexico and Colorado and the Midcontinent Rift System, a rock formation that extends from Kansas to Ontario to Michigan. Other promising regions include the California coast and the Eastern seaboard, according to the agency.

In February 2024, Koloma raised $246 million in venture capital for geologic hydrogen exploration and extraction in the US.

"We're pretty confident that there is hydrogen," Carly Anderson, a principal at Prelude Ventures, an investor in Koloma, said in a separate interview.

The challenge is "figuring out how to get the hydrogen out of the ground," Anderson added.

Another challenge is that each individual hydrogen deposit is not likely to be very big, according to Wicks. For this reason, he is overseeing several research projects with universities and DOE labs that aim to expand those deposits by injecting some sort of catalyst into the ground.

"My personal opinion is, we're not going to find the Permian Basin of hydrogen," Wicks said. "But we have the advantage that if you find a situation that hydrogen is accumulating, then you just drill under it and stimulate it."

Steps to deployment

The DOE's Advanced Research Projects Agency has been testing various "secret sauces" for nine months and has already seen massive improvements in hydrogen yields, Wicks said. Many of the teams' deployment methods are borrowed from the oil and gas industry.

"It's drilling holes," he said. "It's stimulating rocks, putting things down, hydraulic fracturing. They know how to do that very well."

Wicks added he expects to see the first commercially producing wells by the end of this decade. "We just have to tell them where and when," he said.

But first, the nascent industry must come up with the resource assessment methodology to make geologic hydrogen bankable, Wicks said. Adding to the challenge is that hydrogen is highly reactive, meaning these reserve volumes are constantly changing.

Another barrier to deployment stems from the fact that hydrogen does not naturally accumulate where there is oil or gas in the subsurface. As a result, some states with potential hydrogen reserves, such as Minnesota, lack the regulatory framework for exploratory drilling operations. Other states with fossil fuel resources elsewhere within their borders, like Kansas, are treating geologic hydrogen as natural gas.

"There's not an agreement among the states of how they're going to classify hydrogen," Wicks said.

Wicks compares the trajectory of geologic hydrogen to fracking, which was first explored by the DOE in the 1980s but was not commercially successful until around 2005.

As far as technological progress, "we're now in the 1990s," Wicks said. But this time, the industry knows what it needs to do to commercialize more quickly, he added. "So we've learned from our past."