Natural hydrogen in Europe: a continental-scale geological prospectivity assessment

Natural hydrogen, generated by geological processes within the Earth's crust, is increasingly recognized as a potential low-carbon energy resource. Unlike green hydrogen, which is currently limited by high production costs, natural hydrogen may offer a continuous and cheaper supply if accessible at scale. Yet systematic assessments of its occurrence remain scarce, particularly at continental scales. Here we present the first Europe-wide natural hydrogen prospectivity map, integrating geological indicators of hydrogen generation (serpentinization, radiolysis and deep sources), reservoir quality and sealing capacity. To quantify geological uncertainty, Monte Carlo simulations were used to generate conservative, median and optimistic prospectivity scenarios. Our results highlight significant high-potential regions (prospectivity >0.8, ∼200 000 km 2 ), particularly in Hungary, Denmark, Poland and Serbia, with model predictions consistent with many known natural hydrogen occurrences. This work identifies priority regions for exploration and offers first-order resource estimates that can inform Europe's hydrogen strategy. By linking geological prospectivity to energy transition goals, we demonstrate that natural hydrogen could complement renewable hydrogen pathways and enhance long-term energy security.