Summary
Highlights
Dr. Jurgen Gr, a sedimentology expert and 'Indiana Jones of geology', introduces natural hydrogen as a much-overlooked energy source in the subsurface. He shares his extensive experience of 31 years in oil and gas exploration with Shell before joining the University of Erlangen-Nürnberg to set up a geoenergy master's program, focusing on natural hydrogen exploration.
Dr. Gr discusses why natural hydrogen has only recently gained attention, despite early discoveries in 1907 (Estonia) and 1910 (Germany). Reasons include the lack of focused exploration, the dominance of hydrocarbon demand, industry's focus on different geological environments, inadequate monitoring by the mining sector, and historical limitations in detection tools and the accessibility of Russian scientific literature.
A Ukrainian geochemist, Sconi, estimated 23 million tons of natural hydrogen emanate annually from published data, while the US Geological Survey suggests hundreds of millions of tons. Dr. Gr emphasizes that the true number remains uncertain, but surface emanations are significant and new discoveries are frequently reported globally.
Serendipity has played a crucial role in discoveries, such as the Mali well, which has been producing natural hydrogen for over 12 years. Dr. Gr advocates for 'play-based exploration,' a systematic, geology-driven approach that involves developing play concepts and searching for specific geological settings using available surface and subsurface data, particularly in areas like southern Germany.
The size of natural hydrogen reservoirs is largely unknown, akin to the early days of the hydrocarbon industry. Dr. Gr notes similarities with petroleum systems, highlighting that natural hydrogen can originate from various sources like serpentinization, radiolysis, or even earthquakes. It primarily migrates to the surface along fault systems and structural elements, providing regenerative pathways.
Most early natural hydrogen startups conduct 'Brownfield exploration,' utilizing existing wells where hydrogen is known to be present, often dissolved in water. These shallow wells are low-cost. Geophysical methods, such as 2D/3D seismic, gravity, and magnetic data, are crucial for understanding the subsurface in 'Greenfield exploration' areas where prior data is scarce.
Natural hydrogen wells are considered relatively low-risk due to their shallow depth and saline aquifers. Emissions estimates for natural hydrogen are significantly lower than green hydrogen. From a socio-economic perspective, natural hydrogen could offer decentralized, local energy production, leading to energy security and sustainable development for communities, particularly through a 'prosumer model'.
Current regulations for natural hydrogen are often non-existent or inadequate, being shoehorned into mining or oil and gas laws. Dr. Gr laments the lack of recognition and incentives for natural hydrogen in national energy strategies, such as Germany's. Effective communication will be vital to inform the public about the benefits and avoid 'non-technical risks'.
Natural hydrogen is expected to be a contributor to the future energy system, offering a low-emission solution and enhancing energy security, especially when used locally to mitigate long-distance transport challenges. The approach should focus on smaller-scale, local, and community-driven solutions rather than large, centralized projects.
Key unanswered questions include the main source of natural hydrogen, the existence of primordial hydrogen, and the nature of conventional reservoirs. Dr. Gr believes Mali is not exceptional and that many similar occurrences will be found. The future outlook involves replicating small-scale pilot developments globally, focusing on areas with market demand.
Effective collaboration requires easy and fast access to digital subsurface data, with initiatives like the European Geoscience Data Infrastructure (EGDI) being crucial. The soil air sampling method, which involves measuring gas concentrations at shallow depths, has revealed high natural hydrogen concentrations in Germany, explained by migration paths.
Academia and industry must collaborate, forming research consortiums and seeking funding. Inspiring the next generation of geoscientists is paramount, as demonstrated by initiatives within the Geological Society of Germany to engage young people. Dr. Gr actively teaches natural hydrogen in his geoenergy class, fostering interest and growth in the field.