Geoffrey Ellis, a geochemist with the Geological Survey visited Fayetteville, North Carolina in February to examine the Carolina bays, a series of elliptical shaped, naturally occurring depressions in the surface of the Earth.

“There’s actually a band of them that go all the way from the Georgia-Florida border all the way up to New Jersey…  and no one really knows how these things formed,” Ellis told Cipher. “One fairly recent theory is that they could be formed by, actually, hydrogen seeping out of the ground.”

Ellis, who testified at a congressional hearing on this topic last week, told lawmakers the USGS only started investigating geologic hydrogen in 2021. His field work embodies the surprisingly recent and rapidly growing interest in searching for hydrogen under our feet.

Underground whirlwind

U.S. Energy Department Secretary Jennifer Granholm calls clean hydrogen the “‘Swiss Army Knife’ of zero-carbon solutions because it can do just about everything.” But producing hydrogen with current technologies takes a lot of energy and is carbon intensive. Geologic hydrogen could sidestep both obstacles, which could ultimately reduce costs.

Last month was particularly busy on this front: In early February, the Energy Department announced it was investing $20 million into 16 projects related to naturally occurring hydrogen. The next day, geologic hydrogen startup Koloma disclosed it raised $245.7 million, the largest private investment in the space to date. Breakthrough Energy Ventures (BEV is a program of Breakthrough Energy, which also supports Cipher) is among its supporters. At the end of February, the Colorado School of Mines and the USGS announced a research collaboration with oil giants and startups including BP, Chevron, Eden Geopower, Petrobras, Fortescue, Koloma, Hydroma USA and HyTerra. Two days later, Senate lawmakers hosted a hearing about geologic hydrogen.

A view of the Carolina Bays from the sky. Photo credit: Landsat imagery courtesy of NASA Goddard Space Flight Center and U.S. Geological Survey.

At the hearing, Ellis told lawmakers about a water well in Mali that exploded in 1987. Prospectors abandoned it. Then, 25 years later, an oil and gas company returned and discovered the gas seeping from the site was 97% hydrogen. Now, the naturally occurring hydrogen found there has provided electricity to a local village for a decade. This “accidental discovery” instigated a “reexamination” of geologic hydrogen, said Ellis.

Pete Johnson, the CEO of Koloma, also spoke at the Senate hearing and previously co-founded a company that developed technology to produce clean hydrogen. He was working as an investor when he learned about geologic hydrogen three years ago, he told lawmakers.

“I was very skeptical. Everybody is looking for a silver bullet in the clean energy business. This one seemed too good to be true,” Johnson said.

While geologic hydrogen is an ultra-hot topic in cleantech right now, it has long been overlooked for, among other reasons, the fundamental fact that it is hard to detect.

“It has no color. It has no smell. It has no taste. It is non-toxic. And it is 15 times lighter than the air. So, it is very difficult to find it in nature if you are not looking for it,” said Viacheslav Zgonnik, CEO of Denver-based Natural Hydrogen Energy, which erected the first drill to tap geologic hydrogen resources in the U.S. in 2019 in Nebraska.

Now, there’s a full-scale treasure hunt for naturally occurring hydrogen. And there’s a feeling among those involved that it’s the solution the world has been waiting for.

“​​Sometimes the most obvious breakthroughs are staring us in the face. And we keep trying to look around them,” says Douglas Wicks, program director for the Energy Department’s investment into research related to accelerating the natural production of geologic hydrogen.

Geoff Ellis, on the right, doing field work in Nebraska looking for sources of naturally occurring hydrogen. Photo credit: Geoff Ellis, United States Geological Society.

‘A paradigm shift’

Ellis and his colleague Sarah Gelman estimate there could be anywhere from billions to quadrillions of metric tons of hydrogen trapped in rocks underground, with the most probable estimate around 5 trillion metric tons, Ellis says. For context, the U.S. produces 10 million metric tons of hydrogen a year, according to the Energy Department.

Although not all will be economically recoverable, if even 2% of the estimated hydrogen could be recovered, that’s 100 billion metric tons of the gas, enough for humanity to draw out 500 million metric tons per year for 200 years, Ellis says. That’s approximately the amount of hydrogen the International Energy Agency has estimated the world needs to reach its net-zero carbon emissions goals in 2050, Ellis says. (Ellis and Gelman’s estimate is included in a research paper currently under review at a journal, Ellis says.)

The potential of virtually limitless quantities of clean hydrogen “represents a paradigm shift” in how hydrogen would play a role in global energy systems, Evelyn Wang, the director of the Advanced Research Projects Agency-Energy (ARPA-E), said at the Senate hearing.

That’s because it takes more energy to produce hydrogen with electrolysis (splitting water with electricity) or with steam-methane reforming (heating natural gas with high-temperature steam) than there is in the resulting hydrogen. But finding and excavating naturally occurring sources of hydrogen should take less energy than the hydrogen itself contains, Wicks says, a crucial distinction in the role hydrogen can play in the future of energy.

“A primary energy source is one in which you get more energy out than you put in to produce it,” Wicks says.

Natural Hydrogen Energy drill is the first built to tap geologic hydrogen in the United states. Photo credit: Viacheslav Zgonnik and Natural Hydrogen Energy LLC.

Excavating natural hydrogen will result in some carbon emissions, like those associated with making drilling equipment. Such emissions will vary significantly from location to location. But in a first-of-its-kind lifecycle assessment, Stanford professor Adam Brandt found in an August 2023 paper that the emissions associated with geologic hydrogen can be low enough to qualify geologic hydrogen as a “source of clean energy,” he writes. (Brandt’s paper was funded by Smart Gas Sciences, a company founded by Tom Darrah, a co-founder of Koloma.)

All of this makes the promise of geologic hydrogen tantalizing.

“This could be the most important development in energy in our lifetimes, and probably in our children’s lifetime. It’s impossible to overestimate how important this is,” says Eric Toone, managing partner at Breakthrough Energy Ventures and chief technology officer at Breakthrough Energy.

Time and research

Still, realizing the potential of geologic hydrogen will require time to build the industry from scratch, research it sufficiently and ensure its environmental footprint is sufficiently limited.

“In the short term, I will tell you right now, the first reservoir somebody finds will not be the best. It’ll take a while to find the Permian of hydrogen,” Johnson told Senators, referring to Texas’ Permian Basin, known for its prolific oil resources.

It will also take time to build up the infrastructure to support the sector. There are 2.6 million miles of pipelines to move oil and gas around the U.S., and merely 1,600 miles of hydrogen pipelines.

While tracking down existing geologic hydrogen resources is a first challenge, the $20 million in APRA-E funding is going toward researching how to accelerate and stimulate the natural geochemical process by which it is made. Not all reserves of naturally occurring hydrogen are going to be accessible and at concentrations economically viable to extract, so helping these natural processes along would increase the quantity of hydrogen we can get out of the ground.

Hydrogen exists in the pores of rocks underground mostly where iron and water react. While the fundamental reaction is understood, there’s still a lot unknown about how these reactions happen on a molecular level underground, says Ben Gilbert, a senior scientist at the Lawrence Berkeley National Lab and a recipient of one of the Energy Department’s research grants.

One way to accelerate most reactions is to add heat. But adding too much heat makes drilling a challenge, Gilbert says, so he’s hoping to understand the hydrogen production process more exactly (by using super computers) so he can figure out how to accelerate the process chemically.

Maria Gabriela Davila Ordonez, a research scientist and chemical engineer at Lawrence Livermore National Laboratory, has also received Energy Department funds to research how to stimulate hydrogen production where it is not currently happening by injecting specific organic acids underground. “One of our main impacts for this project will be analyzing or quantifying the change in the physical properties in the rock,” Davila Ordonez says.

Another hurdle will be getting the hydrogen up to the surface at what Wicks calls “a reasonable purity.”

Startup Eden GeoPower is trying to solve this problem by fracturing rocks with a high voltage burst of electricity, an alternative to hydraulic fracturing, says CEO Paris Smalls. The shocking fractures rocks more precisely, allowing prospectors to maximize the surface area they can access to stimulate the reaction. Plus, the electric shocking makes the rocks hotter, which also helps accelerate the hydrogen-producing reaction.

The tool Eden GeoPower uses to shoot electricity into a geologic hydrogen well. Photo credit: Eden GeoPower.

Unlike hydraulic fracturing, the electric rock shocking technology does not use pressurized water to break the rocks, potentially saving up to 5 million gallons of water per well and reducing possible seismic activity, Smalls says.

The company was one of the recipients of the 16 Energy Department grants and is bringing its technical know-how to a bilateral cooperative agreement with the Sultanate of Oman to advance geologic hydrogen knowledge. Oman has particularly rich resources of underground hydrogen.

While the hunt for geologic hydrogen is still in its very early days, the business case is already clear, says Toone.

“We know how to make zero carbon hydrogen,” he says. “It’s just too expensive. That’s what’s important about geologic hydrogen, is it offers the possibility of having zero carbon hydrogen at a fraction of the cost that we can have it today.”

Editor’s note: Koloma’s investors include Breakthrough Energy Ventures, which is a program of Breakthrough Energy, which also supports Cipher. Eric Toone is managing partner at Breakthrough Energy Ventures and chief technology officer at Breakthrough Energy.