How much hydrogen is stored in the ground? How can deposits be identified and extracted? And which business cases could emerge? ESYS experts address these questions in the Discussion Paper “Geological Hydrogen – an overlooked energy source?”. ESYS is a joint initiative of acatech, Leopoldina and the Union of Academies.
Uncertain whether economically viable deposits exist
The geological processes that generate hydrogen are relatively well understood. However, reliable data is missing on whether the generated hydrogen accumulates in reservoirs and could be extracted economically.
Karen Pittel (Deputy Chair of the ESYS Board of Directors; ifo Institute) explains: “Discussions with international experts, on which this paper is based on, show that it is difficult to estimate natural hydrogen resources because several challenges arise at the same time: We still know little about how hydrogen migrates, accumulates, and is stored in rock formations. According to our experts, only one reservoir worldwide – in Mali – has been discovered and used for energy production so far.” In addition, it often remains unclear whether hydrogen measured in the ground really originates from geological processes. It can also result from microbial activity or be formed during drilling through friction or corrosion.
Potentially low-cost, but not a large-scale game changer
If extractable hydrogen deposits were found, production costs would likely be much lower than for green hydrogen produced via electrolysis. However, natural hydrogen would probably not replace green hydrogen – most experts see it as an addition. Decentralised applications appear especially promising. These include co-production with helium or geothermal energy, and local energy supply.
Regulatory clarity and targeted research funding needed
Regulatory frameworks for exploring and extracting natural hydrogen vary widely across countries and sometimes hinder exploration. In Germany, hydrogen is currently not classified as a freely mineable resource (“bergfrei”) – therefore, exploration and extraction require the consent of the landowners beneath whose land the deposit is located. Including it in the list of such resources, as proposed in the German Hydrogen Acceleration Act (“Wasserstoff-Beschleunigungsgesetz”), could facilitate exploration and future extraction. In addition, targeted public funding could speed up research and enable a more robust assessment of whether natural hydrogen can play a role as a resource in the future.