The study represents the result of detailed geological and modeling analyses aimed at reconstructing the geothermal potential of the Italian territory and determining the feasibility, potential, and sustainability of thermal exchange processes with the subsurface in closed-loop geothermal systems. The innovative aspect of the proposed system involves the use of unconventional wells, where the process fluid heats up at depth without direct physical contact with deep geological formations. This system represents an important step forward in geothermal technology because, without the need for a “conventional” geothermal reservoir, it significantly increases geothermal production potential in Italy and represents a highly efficient production system.

The first part of the report provides a general overview, defining the potential and end uses of geothermal resources, the environmental aspects of its use, and the methods and techniques of exploration employed to identify reservoirs potentially exploitable for the production of electric and thermal energy.

Following this discussion, the report presents the results of the research, the outcome of a multi-phase process.

In the first step, geological, hydrogeological, and thermal data from the geothermal resource archive of the former DGS-UNMIG Directorate of the Ministry of Economic Development (MiSE) were collected and processed to create, within a GIS environment, the geothermal zoning of the Italian territory at a municipal scale.

In the second step, the volumetric method was identified as the most effective method for estimating geothermal electricity production potential in Italy. This method was also calibrated based on production data from operating fields in Italy.

The third step involved conducting geological modeling studies for two areas in Italy that differ in rock types and the presence or absence of geothermal fluids. For the first site, a large area in Lombardy characterized by the absence of geothermal fluid, the first fluid dynamic simulation scenarios were performed by inserting unconventional closed-loop wells into terrigenous formations. For the second site, named Castel Giorgio – Torre Alfina (TR), only the geological model of the geothermal reservoir, characterized by the presence of fluids with temperatures of 120°-150°C in carbonate formations, has been developed so far.