Early-Stage Hydrogen Exploration: From Existing Data to Regional Favorability Mapping in Nouvelle-Aquitaine (France)

As part of the transition to low carbon energy, the exploration of natural hydrogen in different tectonic settings is an important step. Here, we propose a pragmatic exploratory approach using the existing geological database, proposing favorability maps and suggesting H2 production and storage systems. We use the Nouvelle Aquitaine region in southwestern France as a case study. This region exhibits a wide geological diversity, ranging from a mountain range peaking at around 3,000 m, a mantle located within a serpentinization window, a basin with petroleum potential, to the exposure of a Hercynian metamorphic basement. Furthermore, this region possesses an extensive geological, geophysical, and geochemical database, most of which is open-access. We also present examples of point and continuous measurements of soil gas in favorable areas, illustrating the large spatial and temporal variability of H2 emissions. The Nouvelle Aquitaine region therefore appears to be a promising area for H2 exploration, as confirmed by the deposit of the first research permit in France.