A national inventory of play types

M. R. Galione, A. Manzella, S. Botteghi, F. Ferrigno, L. Yang and E. Trumpy have published in the journal Geothermal Energy a study that assesses, for the first time, geothermal systems across the whole of Italy in a systematic way. As they note, Italy has a long history of geothermal use, yet a comprehensive, up-to-date national assessment had been missing. The aim was to build a uniform, transparent and repeatable reference that allows geothermal systems in Italy to be compared with one another and with other geological settings in Europe.

The play concept and six types

The assessment combines geological, tectonic, geothermal and utilisation data within a GIS environment. The authors identify 27 plays and group them into six main categories. Convection-dominated systems cover volcanic, plutonic and extensional domains, while conduction-dominated ones cover foreland basins, the orogenic belt and basement rock provinces. This yields the first geothermal play type map for Italy.

Heat potential and storage

From among the identified types, 17 key play reservoirs were analysed using borehole temperature data, lithostratigraphy, reservoir geometry and petrophysical parameters taken from the literature. Heat potential was estimated with volumetric methods as Heat in Place and, where possible, also as heat storage potential for aquifer thermal energy storage (ATES) at medium and high temperatures. Uncertainty was handled through Monte Carlo simulations.

Conclusions

The findings confirm the very high potential of convection-dominated plutonic systems in Tuscany, where all currently operating geothermal power plants are located. At the same time, conduction-dominated sedimentary basins, particularly in the Po Plain, hold substantial potential for direct heat use and thermal energy storage, backed by large reservoir volumes and favourable petrophysical properties. The authors point out that Italy's geothermal potential reaches well beyond the traditional magmatic areas. The work received support from the EU's GSEU project under the Horizon Europe programme.