Conference Agenda

Natural hydrogen, produced by geological processes within the Earth’s crust, is gaining attention as a potentially low-carbon energy resource. Compared with green hydrogen, whose deployment is still constrained by high production costs, natural hydrogen could provide a continuous and lower-cost supply if recoverable at scale. However, systematic assessments of its occurrence remain limited, especially at continental scales.
Here, we present the first Europe-wide natural hydrogen prospectivity map, integrating key geological indicators related to hydrogen generation, including serpentinization, radiolysis, and deep-sourced contributions, together with reservoir quality and sealing capacity. To account for geological uncertainty, we applied Monte Carlo simulations to generate conservative, median, and optimistic prospectivity scenarios.
Our results identify extensive high-potential areas, defined by prospectivity values greater than 0.8, covering approximately 200,000 km². These areas are particularly prominent in Hungary, Denmark, Poland, and Serbia. Model predictions are broadly consistent with many known natural hydrogen occurrences, supporting the validity of the approach.
This study highlights priority regions for future exploration and provides first-order resource estimates relevant to Europe’s emerging hydrogen strategy. By linking geological prospectivity with energy transition objectives, we show that natural hydrogen could complement renewable hydrogen pathways and contribute to long-term energy security

Wasserstoff gewinnt zunehmend an Bedeutung als potenzieller Baustein der Energiewende. Im Mittelpunkt des aktuellen Forschungsprojekts stehen mögliche Vorkommen geogener Wasserstoffquellen („weißer Wasserstoff“) und die Migration weiterer natürlicher Gase aus der Erdkruste in Baden-Württemberg. Erste Ergebnisse identifizieren Gasaustritte, die überwiegend Methan (CH₄) in entzündbaren Konzentrationen enthalten, CO₂ und in geringen Anteilen Wasserstoff. Kartierungen der Gasaustritte, Gasmessungen in Kombination mit Isotopenanalysen und die Aufnahme natürlicher Brüche in Aufschlüssen sind die Grundlage um das Potential natürlicher Wasserstoffvorkommen zu untersuchen. Bodengasmessstellen an beobachteten Gasaustrittsstellen ermöglichen ein Langzeitmonitoring und eine Beprobung für Laboranalytik. Bruchstrukturen und demnach potenzielle Migrationspfade der Gase werden mittels LiDAR an Karbonatgesteinen analysiert. Die Integration dieser Daten ermöglicht eine verbesserte Einordnung der Prozesse und der räumlich-zeitlichen Dynamik der Gasaustritte. Die Ergebnisse liefern erste Erkenntnisse über potentielle natürliche Wasserstoffsysteme und bilden eine Basis für zukünftige Explorationen.

Water–rock interactions in ultramafic systems are a major source of natural hydrogen, yet their occurrence and trapping mechanisms in ophiolites remain under-constrained. We collected serpentinized and rodingitized ultramafic rocks from the Troodos ophiolitic complex (Cyprus) to investigate H₂ in fluid inclusions and assess its spatial distribution. Samples from multiple localities in the central Troodos massif and south of the Arakapas Transform Fault Zone (Limassol Forest) were examined by thin-section petrography and Raman microspectroscopy.

Fluid inclusions occur in clinopyroxene, chromite, and titanite across diverse lithologies, including harzburgite, dunite, chromitite, (pegmatic) gabbro, anorthosite, diopsidite, and rodingite. Raman spectra confirm abundant H₂-bearing inclusions in diopside and chromite. In diopside, inclusions are up to 15 µm in length; inclusion shapes vary between regular and irregular. The volume fraction of the vapour phase varies between 30 and 80 vol.%, and the vapour contains pure H₂ and H₂-CH₄ mixtures. The liquid phase is a moderate saline brine.

H₂ is consistently associated with CH₄ in small clusters in chromite, whereas trails of negative crystal-shaped methane inclusions also occur. In most samples, the most common serpentine polymorph is lizardite, indicating relatively low-temperature alteration conditions.

The presence of H₂-bearing inclusions in both central Troodos and the Limassol Forest indicates that hydrogen generation and trapping accompanied serpentinization and rodingitization across a broad area. These results provide direct spectroscopic evidence for natural hydrogen in the Troodos ophiolite and a sound basis for further microthermometric investigations.

Natural hydrogen is regarded as a key resource in a future low carbon energy system. Despite major scientific and technological breakthroughs, the efficient acquisition and comprehensive interpretation of significant exploration data remains a challenge to unlocking its global resource potential.

Soil gas measurements represent a cost-efficient, fast, and easily applicable surface-based screening method that allows for a quick first-order characterization of an area’s natural hydrogen potential. Data interpretation, however, is complex and results might be ambiguous in case the geological setting, different environmental impact factors or potential sampling artefacts are not sufficiently considered. In particular, neglecting the influence of microbial activity in the soil zone can lead to misinterpretation of deep hydrogen signals. Mud gas analyses provide precise information that helps to identify hydrogen occurrences while drilling. Drill bit metamorphism and associated processes, however, may produce gas artefacts mimicking naturally hydrogen-bearing zones.

We present two natural hydrogen exploration case studies in which high hydrogen concentrations encountered in mud gas (~70 vol%) while drilling in partly serpentinized ultramafic rocks and during a soil gas survey (>1000 ppmv) could be attributed to drilling-induced hydrogen generation (oxidation and mechano-chemical reactions) and microbial activity in soil, respectively, based on interdisciplinary workflows including gas geochemistry, hydrochemistry, soil studies, and microbiology. Our results highlight current challenges in natural hydrogen system analysis, from which recommendations for an improved multi-analytical exploration workflow can be derived.