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 H 2 emissions. The Voltri Massif shows moderate potential linked to active serpentinization, while the Northern Apennines may potentially preserve fossil H 2 . In the Ivrea–Verbano Zone, granitoids of Calabria and Sardinia, and in the Western and Central Alps, H 2 could be generated from low-temperature secondary oxidation reactions. The Po Basin may sustain organic-related H 2 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.