At the turn of the 20th century, Paris faced a monumental challenge in constructing its iconic metro system. The city’s unstable, waterlogged soil near its riverbanks made underground tunnelling risky. Ingenious engineers overcame this obstacle by building the Cité and Saint-Michel metro stations above ground and then carefully sinking them into the earth. To cross the river, they employed groundbreaking techniques, such as freezing the ground and encasing structures in tubes before lowering them into the riverbed. These bold engineering feats set the stage for many of Paris's most visionary infrastructural achievements.
Today, a similar spirit of innovation is driving a quiet revolution in the energy sector, specifically in the harnessing of Natural Hydrogen. While hydrogen has long been touted as a key solution for a cleaner energy future, traditional production methods, such as steam methane reforming and electrolysis, remain energy-intensive and still rely on fossil fuels or unsustainable electricity. Natural Hydrogen, however, presents a more sustainable alternative. Found naturally in certain deep geological formations, this form of hydrogen could dramatically shift how we produce and use this clean fuel.
Recent advancements in understanding and extracting Natural Hydrogen have captivated the scientific community. Unlike traditional hydrogen production, which involves extracting Hydrogen from water or natural gas, Natural Hydrogen is already stored deep beneath the Earth's surface, in aquifers and volcanic rock formations. This presents an opportunity to access Hydrogen at scale, without the significant energy input or environmental impact of conventional methods. Geological surveys in regions like Western Africa, the Middle East, and North America have revealed substantial reserves of this naturally occurring Hydrogen, suggesting that it may be more widespread than previously thought. This discovery has the potential to transform the global energy landscape.
Jacques Pironon and his colleague Philippe de Donato, both CNRS researchers, in charge of the REGALOR research program of the GeoRessources laboratory at the University of Lorraine (supported by the Grand-Est region and the FEDER) are at the forefront of this research. Pironon and his team are developing advanced drilling techniques and sophisticated geological mapping methods to locate and extract Natural Hydrogen with minimal energy waste. Their work aims to unlock the full potential of this resource, enabling large-scale production that could provide a cleaner, more efficient alternative to fossil fuel-based Hydrogen production. The implications are profound: a scalable, low-impact source of Hydrogen that could help power industries, vehicles, and homes, contributing significantly to the decarbonisation of the global economy.
The potential of Natural Hydrogen to reshape energy production is immense. If large reserves can be extracted and commercialised, it could drastically accelerate the transition to a sustainable energy system. Just as the engineers of the Paris Metro overcame technical challenges to reshape the city’s future, today’s innovators are unlocking Earth’s hidden resources to help create a cleaner, greener energy landscape. Natural Hydrogen is poised to become a cornerstone of the global energy transition, a game-changer that will help power a sustainable future.
Jacques Pironon leads groundbreaking research into Natural Hydrogen. In this interview, he shares his expertise on the exploration, production, and future of this sustainable energy resource, offering insights into its potential and the innovative techniques to unlock its full promise.
Exploration and Production: Given your expertise in georesources, what are the most promising geological formations or regions for the exploration and production of natural hydrogen, and how does this differ from traditional hydrogen production methods?
Jacques Pironon:"First of all, it must be said that natural hydrogen is the only form of primary energy derived from hydrogen. Other types of hydrogen (grey, black, blue, turquoise, yellow, pink, green, etc.) are secondary energies, hydrogen being an energy vector. We then transform a primary energy (fossil, nuclear, renewable) into hydrogen to transport and store it. Natural hydrogen is present in many geological contexts, such as mid-ocean ridges, ophiolitic/serpentinite bodies, formations rich in coal and hydrocarbons, formations rich in radioactive ore, etc. Hydrogen is the most abundant element in the universe."
Economic Viability: From a cost perspective, how does the extraction of natural hydrogen compare to other hydrogen production methods such as electrolysis and steam methane reforming? What advancements would be needed to make it economically competitive?
Jacques Pironon:"There is no market for natural hydrogen today. This market is to be built, and it is obviously conditioned by the discovery of deposits. Nevertheless, we find estimates in the newspapers between 1 and 3 €/kg. Today, the production of 'green' hydrogen costs on average 5 to 10 euros per kilo, depending on the size and nature of the production units, compared to only 1.50 to 2 euros for 'grey' hydrogen produced from natural gas. Natural hydrogen will require its own production infrastructures (drilling, separation, drying, storage, pressurisation units) similar to the infrastructures of the natural gas sector."
Environmental Impact: One of the key appeals of hydrogen is its potential for decarbonisation. How does the environmental footprint of natural hydrogen extraction compare to other methods of hydrogen production in terms of emissions, energy consumption, and land use?
Jacques Pironon:"The environmental impact of a production unit in Lorraine should be reduced to a minimum. Indeed, our project is revolutionary because it aims to produce hydrogen in dissolved form in an aquifer. This has never been done. The idea is to 'build' a plant underground where the gases will be separated from the water, and where they can perhaps be purified. Thus, the water remains underground and does not pass through the surface; the separation units could also be deep down, thus considerably reducing the footprint. Extraction limited to dissolved gases would generate almost no seismic movement. Gas extraction is based on the pressure differential between the high pressure of the gases at depth and the atmospheric pressure at the surface and should not require energy."
Technological Challenges: What are the key technical challenges that need to be overcome in order to efficiently locate and extract natural hydrogen at a commercial scale? Are there any recent breakthroughs in this field that you find particularly promising?
Jacques Pironon:"The technological challenges lie in our ability to extract large quantities of gas from the aquifer by wells in order to reduce the number of wells and reduce production costs. We have made great progress in separation technologies, but we still need to transpose them to deep underground environments."
Future Outlook: How do you see the role of natural hydrogen evolving within the broader hydrogen economy in the next 5–10 years? Could it play a significant role in meeting global hydrogen demand, or will it remain a niche resource?
Jacques Pironon:"It is difficult to answer this question because we are really seeing the start of the sector. We are convinced that the exploitation of dissolved gases is a new avenue of progress and that it offers great prospects: producing gases that are not concentrated in the form of pockets of gas like methane but that are present in a dissolved state, bringing production sites closer to consumers because the aquifers are very extensive, and exploring targets that are broader than those of conventional gas exploration. This concept is perhaps a great opportunity for Europe, whose conventional gas reserves are running out."
Jacques Pironon’s research highlights the transformative potential of Natural Hydrogen as a sustainable energy source, drawing a compelling parallel to the challenges faced by engineers over a century ago in Paris. Just as Metro engineers had to devise solutions to navigate the waterlogged earth while sinking tunnels beneath the city, Pironon’s methodologies employ similar techniques to extract Hydrogen from deep geological formations by placing electrolyser underground. This comparison highlights how lessons learned from past engineering innovations are informing today’s search for Natural Hydrogen, illustrating a modern spirit of underground innovation aimed at unlocking the potential of this subterranean resource.
Looking ahead, the role of Natural Hydrogen in the broader hydrogen economy is set to grow, though challenges remain. Over the next five to ten years, as extraction technologies improve and the necessary infrastructure is put in place, Natural Hydrogen could emerge as a competitive alternative to traditional methods of production. With its scalability and environmental advantages, it holds significant potential for decarbonising industries, transport, and energy generation.
Pironon’s research suggests that Natural Hydrogen’s ability to be produced locally, in proximity to consumers, will be key, especially in regions like Europe, where conventional gas reserves are depleting. As these innovations are scaled up, Natural Hydrogen could become a cornerstone of the global clean energy transition, helping to meet the growing demand for Hydrogen while reducing the environmental impact of energy production. The next decade could see a shift from niche exploration to large-scale production, unlocking a new era of sustainable energy solutions.
