Natural hydrogen – also called white, gold, or geologic hydrogen – is the latest buzzword as the transition away from fossil fuels gains steam.

Found underground, white hydrogen is produced by natural geochemical processes such as serpentinization (when water reacts with iron-rich minerals at high temperatures) and water radiolysis (radiation-driven splitting of water). Interestingly, natural hydrogen was discovered accidentally in 1987 ​​in the village of Bourakébougou in Mali during a water drilling campaign in an existing well. Nearly two decades later, further exploration at the site discovered reservoirs with hydrogen, which is now being used to fuel a small turbine in the village.

Cut to the end of 2023, as many as 40 companies were exploring natural hydrogen, up from just 10 three years before, according to a recent report by Rystad Energy. Exploration is underway across the globe, including in Australia, France, Canada, Spain, Albania, Colombia, South Korea, and the US.

So, what’s causing this new “white gold rush”?

“If natural hydrogen extraction can prove to deliver a significant amount that has been estimated, it can play a key role in helping us achieve the hydrogen volume needed to reach our climate goals,” Minh Khoi Le, head of hydrogen research at Rystad Energy, told Kallanish. 

Moreover, natural hydrogen is estimated to cost much less than existing hydrogen production. Grey hydrogen, which is derived from fossil fuels, costs an average of $2 per kilogram of hydrogen, while green hydrogen, produced using renewable energy, costs thrice as much, according to Rystad. In contrast, developers in Spain and Australia predict natural hydrogen to cost as little as $1/kg. Canada-based Hydroma, which is the only current producer of white hydrogen, is producing around 5 tonnes/year of hydrogen from the Mali well at an estimated cost of $0.5/kg. 

“From Rystad Energy hydrogen database, the announced capacity of blue and green hydrogen is only a third of what we need if we want to stay on track to some of our net zero goals,” Le said. 

In addition, geologic hydrogen has low carbon intensity. “At a hydrogen content of 85% and minimal methane contamination, the carbon intensity is around 0.4 kg carbon dioxide equivalent (CO2e) per kg hydrogen gas,” the report estimates. At 75% hydrogen and 22% methane, the intensity goes up to 1.5 kg CO2e/kg hydrogen.

Geologic hydrogen’s cost-competitiveness and low carbon intensity, combined with the scalability issues of green hydrogen, are now driving the increased interest in the fuel. 

Natural hydrogen projects

Last year, researchers “chanced upon” what could potentially be the largest white hydrogen deposit in the world in Lorraine, southeastern France. In South Australia, natural hydrogen explorer Gold Hydrogen recently began exploration well tests; its move came after the initial drill results from the company’s Ramsay project returned natural hydrogen at up to 86% purity. 

In Aragón, northeast Spain, Helios Aragon is attempting to develop Europe’s first natural hydrogen production project. More recently, US-based construction engineering group Black & Veatch agreed to study natural hydrogen exploration and extraction in South Australia as part of a government-funded project for hydrogen firm H2EX.

While many countries can tap into geologic hydrogen, those with experience in licensing, exploration and extraction of other natural resources enjoy an advantage over others.

“Midstream, demand proximity, potential for economic support from government will also play a role in the potential of countries, even if sizeable natural hydrogen deposits are discovered,” Le added.

Governments are certainly taking notice. In Australia, for instance, the South Australia government added hydrogen to the list of regulated substances in 2021, allowing companies like Gold Hydrogen to apply for exploration permits. In February this year, the US Department of Energy announced $20 million in research grants to 16 projects to advance geologic hydrogen exploration. Last December, French President Emmanuel Macron promised “massive funding” to explore the potential of white hydrogen. 

With hydrogen a key decarbonisation priority for most nations, government support will likely increase in the coming years.

Challenges remain

Despite the momentum in natural hydrogen exploration, challenges remain, mainly because white hydrogen extraction has never been done at scale. The detection, extraction and processing technologies have not yet been tested extensively to have the necessary proven track record.  

“The key is to understand if hydrogen exists in significant accumulations that can be economically accessed, and if so, how to find these resources,” noted Geoffrey Ellis, a geologist with the US Geological Survey (USGS).

In addition, the transportation and distribution challenges of hydrogen also persist, as natural hydrogen may not necessarily be found where it is needed the most. Experts also caution that despite being abundant, most natural hydrogen will not be accessible or easy to recover, and its extraction will also have environmental impacts.

“Like all forms of hydrogen, geologic hydrogen will not necessarily be low-emission –despite claims that extracting it will be cleaner than producing hydrogen from both renewable and fossil fuel energy sources,” the Hydrogen Science Coalition said recently.

Currently, hydrogen can be extracted by drilling into reservoirs – much like oil and gas. Other methods include directly tapping into source rocks or pumping water into the rocks. Emissions from the energy used to power the extraction process, waste products, and leakage of hydrogen and other gases, can all have environmental impacts.

In addition, due to the industry’s nascent nature, there is little to no regulation currently in place to address potential risks and environmental impacts during exploration and production.

Similarly, questions have also been raised about geologic hydrogen’s “renewable” nature. The French research agency CNRS argues that white hydrogen is not a renewable resource as current production rates are “far too slow compared to the world’s energy needs.”

“Future finds of hydrogen in reservoirs suitable for continuous, commercial-scale collection of the gas would present a very welcome opportunity to decarbonise current-day hydrogen production,” the coalition said. “However, considering findings to date, what we know about geologic hydrogen systems, and the fact that favourable settings appear rare, the odds of finding geologic hydrogen that can be extracted at the scale of large natural gas developments looks relatively slim.”

Source: Kallanish, company announcements