Last year, while hunting for methane in the Lorraine Basin in northeast France, Professor Jacques Pironon’s team uncovered an unexpected finding.
They discovered a massive hydrogen deposit around 3,000 meters underground.
“It is what we call serendipity,” explains Professor Pironon, research director of France’s Centre National de la Recherche Scientifique (CNRS) at the University of Lorraine. Not long ago, such a discovery would have been just academic curiosity, but it now causes quite a commotion. One element that receives much attention in the effort to decarbonise the planet is hydrogen. Alberto Vitale Brovarone, a professor at the Department of Biological, Geological, and Environmental Sciences at the University of Bologna in Italy, argues that burning it produces simply water and has no environmental impact. Many believe hydrogen will become a crucial fuel in the coming years. They say that because hydrogen produces no CO2 when used as a fuel or in industrial operations, it may be the key to transitioning the world economy to net zero emissions.
There’s only one problem. Creating hydrogen for various industrial uses is an energy-intensive process, and the resulting hydrogen is only as green as the energy source used to produce it. According to the Carbon Trust, fewer than 1% of worldwide hydrogen generation is zero-emission. Hydrogen is already widely employed in heavy industries. Nonetheless, the great majority of it is produced using fossil fuels (known as ‘grey hydrogen’), contradicting the objective of decarbonisation. ‘Blue hydrogen’ refers to hydrogen generated from natural gas, which emits less than other fossil fuels and is viewed by some as a step towards full decarbonisation. However, the real excitement is about green hydrogen, created using renewable energy. As a result, it is seen as a clean energy source with the potential to play a key role in the worldwide clean energy transition.
However, there is a significant drawback to green hydrogen. The International Renewable Energy Agency (IRENA) issued a paper in 2022 warning against the “indiscriminate use of hydrogen,” claiming that widespread usage of hydrogen “may not be in line with the requirements of a decarbonised world.” The research claims that manufacturing green hydrogen needs massive amounts of clean energy that may be better employed in other uses, making scale production of green hydrogen detrimental to meeting climate targets. However, a new hue has been introduced to the hydrogen rainbow, which has the potential to entirely bypass the problems that current methods of hydrogen synthesis confront. Gold hydrogen (also known as white hydrogen) is a term used to describe hydrogen that exists naturally in some geological places of the planet (subsurface geologic accumulations, to be specific), sometimes in large amounts. It is formed underground when water combines chemically with iron-rich rocks or radioactive materials. And it is the new holy grail of hydrogen research. “Compared to other types of hydrogen, it does not require energy to be produced,” Vitale Brovarone explains. He says a gold hydrogen rush is on the way.
The French were not the first to find naturally occurring hydrogen. There is already a tiny well in Bourakébougou, western Mali, and huge reserves are thought to exist in the United States, Australia, Russia, and numerous European nations. However, the discovery in France is considered the greatest naturally occurring gas deposit ever known. Professor Pironon believes there might be 250 million tonnes of hydrogen, enough to supply world demand for over two years. Many additional hydrogen resources may remain uncovered across the planet, according to the US Geological Survey (USGS), with estimates ranging from hundreds to billions of megatons. It also raises issues about how the element accumulates in reservoirs and how it affects subterranean ecosystems. Some concerns already exist: geological hydrogen might generate methane or hydrogen sulphide when reacting with geological substrates or digested by certain microbes. Vitale Brovarone uses these two instances to show why plunging headfirst into extracting gold hydrogen risks generates new issues rather than fixing current ones and why additional knowledge is required.
“Since we do not fully know what has been regulating the presence of H2 rocks for millions or billions of years, it is better to wait before breaking them by extracting the element,” suggests Vitale Brovarone. Similarly, artificially created hydrogen can be stored in subsurface reserves. The prospect of being able to do so has already piqued the industry’s interest, driving it to act in a timescale that is incompatible with what the scientific community need to understand how the gas acts. Unlike France, Australia, and the United States, which focus on harvesting gold hydrogen, Italy has yet to invest in gathering it, opting to gamble on hydrogen production instead. They’ve become one of the few countries trying to learn more about it.
According to an estimate published in Earth-Science Reviews in 2020, we may harvest 23 million tonnes of hydrogen annually from the ground. And a new generation of businesses is already attempting to accomplish just that. One such firm is Natural Hydrogen Energy (NH2E), established by Viacheslav Zgonnik, the scientist who published the 2020 Earth-Science Reviews study. Zgonnik believes the potential for gold hydrogen extraction is significantly bigger than his paper’s conservative assessment of existing tappable reserves implies.
Not everyone shares Zgonnik’s optimism, however. Reporting on gold hydrogen is riddled with limitations. While there is a lot of excitement about the fuel’s potential, it is just too early to declare gold hydrogen a silver bullet for the environment. It’s virtually untested; Bourakébougou in Mali is the only spot where a working hydrogen well is already being utilised as a fuel source. Furthermore, several investigations must be undertaken to assess how pure this subsurface hydrogen is. Many experts are afraid that extracting the stored hydrogen would result in the emission of greenhouse gases. Others worry that hydrogen exploration will result in the finding and usage of additional fossil fuel deposits.
