Golden hydrogen—or fool’s gold?

It’s lovely to think there are vast sources of continuously produced clean hydrogen from chemical reactions of water on hot rocks within the Earth, ready to be tapped as a clean energy source and solve the world’s energy problems.

It’s a great story—easy to sell—but it’s likely too good to be true.

Over a century ago, Ernst Erdman discovered a stream of hydrogen gas flowing into a salt mine in Strassfurt, Germany. Since then, earth scientists have identified a number of natural sources of hydrogen gas, including hydrogen produced from microbes, radiation, and reactions of water with certain minerals.

In 1966, Thomas Thayer from the USGS proposed that the chemical changes of common minerals rich in relatively reduced iron atoms such as olivine (Fe²⁺) could undergo chemical changes in the presence of water and produce oxidized minerals such as serpentine (Fe³⁺), breaking water into its base components: oxygen and hydrogen gas. This “serpentinization” reaction is thought to be responsible for the hydrogen gas found in many wells around the world.

Through the 1980s, geologists and commercial drilling operations identified common but scattered sources of hydrogen and other naturally occurring gases including helium, carbon dioxide, nitrogen, and hydrogen sulfide, in addition to what is commonly called natural gas (mostly methane). In Kansas, two wells drilled in 1981 and 1982 by the CFA Oil Company were found to produce over 20 percent hydrogen gas for over five years.

In rare instances, people have been able to tap into these natural hydrogen sources and use them as fuel. A natural hydrogen well has been supplying carbon dioxide-free fuel to power a small generator for a community in Mali since 2012. The well was discovered accidently in 1987 while drilling for water. Workers discovered the flammable gas when one of the well diggers lit a cigarette and accidentally ignited the gas, causing significant burns. The well was sealed and temporarily abandoned. Almost 20 years later, in 2011, Aliou Diallo, a Malian businessman and chair of the oil and gas company, Petroma, unsealed the well after acquiring rights to the surrounding gas field and demonstrated the gas was 98 percent hydrogen.

Diallo recognized the potential of geohydrogen and changed the name of Petroma to Hydroma to focus on exploiting the potential of geohydrogen. With the recent resurgence of interest in hydrogen as a clean fuel, a plethora of other start-ups with significant investments from highly respected investors including the Bill Gates-founded firm Breakthrough Energy Ventures are drilling around the world for naturally produced hydrogen, nicknamed “gold hydrogen.”

Comparisons are often made to the shale gas revolution that followed the decline in US oil and gas production in the 1980s. Innovations in horizontal drilling and hydraulic fracking made possible an extraordinary resurgence of hydrocarbon production in the United States starting in the mid-2000s. What these comparisons overlook, however, is that the massive shale hydrocarbon resource was already known to exist. It was innovation in drilling technologies that allowed the resource to be economically exploited and enabled the United States to become the world’s leading producer of oil and gas.

Natural hydrogen is different. Although hydrogen is the most abundant element in the universe, on Earth there are no proven accumulations of large quantities of molecular hydrogen; it is very hard to trap. Although the possible chemistries for making it in the earth are well known, the size, depth, and gas composition of any large, hydrogen-containing fields are unknown. Without this basic information, the costs of extracting, purifying, and transporting any hydrogen products to customers cannot be estimated. In places such as Mali, where the consumers are living on top of the resource, there may be significant local benefits, but the large-scale production and long-distance transport of natural hydrogen will be much more challenging, if large sources are ever found.

Recent claims by scientists at the University of Lorraine that a field in northeast France contained up to 250 million tons of almost pure hydrogen have yet to be independently verified. The United States Geological Survey is presently building a global resource model to help estimate the potential for geohydrogen; it may help determine for the general public the potential impact of natural hydrogen resources.

But wait—last I checked, global energy companies spend billions drilling in the most inhospitable places on the planet to bring society low-cost molecules to burn, providing the power necessary for increasing global prosperity and making billions more for themselves. The Exxons, Shells, and BPs of the world employ the best geologists, geophysicists, and drillers on Earth. Having drilled most everywhere on the planet, it is hard to imagine that they would have overlooked large quantities of hydrogen waiting to be recovered economically.

Some have suggested they did find hydrogen while drilling, but moved on when there was no oil or gas. What? Hydrogen has been known to be a valuable chemical and combustion fuel for over 100 years. These guys want to make money and know how to get molecules economically out of the ground—is it likely they would have overlooked or dismissed a vast new resource?

Geologic hydrogen is powering the energy needs of one small community in Mali, and if more is found to be economically recoverable we can all celebrate. No doubt the many new ventures drilling for gold hydrogen will find some and continue to create buzz amongst investors and on social media, regardless of the real impact.

Meanwhile, hydrogen will continue to be an essential industrial chemical, used to produce ammonia and make low-cost fertilizers that maintain the world’s food supply. We can all hope that geohydrogen is a large, economically competitive resource that until now was simply missed, but hope is not a strategy to manage the real challenges we face in transitioning from our dependence on finite fossil resources.

Innovation is continuing in efforts to produce hydrogen at large-scale without carbon dioxide, using a number of different technologies differentiated by their colors: green and pink hydrogen made by electrolysis using renewable energy or nuclear power, blue hydrogen produced by reforming and capturing the carbon dioxide emitted during production and storing it underground, or turquoise hydrogen produced by decomposing natural gas into solid carbon and hydrogen. Though some of these efforts appear promising, without a meaningful tax or other cost associated with carbon dioxide emissions, it is not possible to compete economically with conventional steam methane reforming, which releases more than five tons of carbon dioxide per ton of hydrogen produced.

Fossil resources are finite, and they will eventually be too expensive to burn, even if their climate impacts don’t force the world to act sooner rather than later. The slow transition to a more economically and environmentally sustainable energy future will be deliberate and probably seem rather boring to most of the public with little buzz on social media. To navigate the inevitable transition most efficiently and equitably will require wise, technically competent leaders and private-sector innovation with a long-term view of human existence and a commitment to continuing prosperity without reliance on hydrocarbon combustion.

While we can all hope to strike it rich and find gold hydrogen, that’s not a solid foundation for climate action.