Quantifying natural hydrogen prospectivity in Italy. A novel pre-exploration workflow for the energy transition

This study presents the first quantitative evaluation of natural hydrogen prospectivity in Italy, developed within the EU-funded NHEAT—Natural Hydrogen for Energy trAnsiTion—project. It integrates geological, geochemical, and geophysical data through a reaction-specific workflow, and introduces a semi-quantitative hydrogen prospectivity index to classify and rank potential exploration target areas, primarily based on source rocks. The results identify Tuscany as the top-priority region, where granitoid-hosted hydrothermal systems are associated with documented H2 emissions. The Voltri Massif shows moderate potential linked to active serpentinization, while the Northern Apennines may potentially preserve fossil H2. In the Ivrea–Verbano Zone, granitoids of Calabria and Sardinia, and in the Western and Central Alps, H2 could be generated from low-temperature secondary oxidation reactions. The Po Basin may sustain organic-related H2 production. This national-scale assessment highlights Italy as a natural laboratory for diverse hydrogen systems and provides a transferable workflow for identifying and developing natural hydrogen resources worldwide.