Ground source heat pumps in Aosta Valley (NW Italy): Assessment of existing systems and planning tools for future installations

The economic viability of shallow geothermal systems with Borehole Heat Exchangers (BHEs) strongly depends on the thermal load which can be efficiently and sustainably exchanged with the ground. This quantity is usually defined as geothermal potential and, as reported in literature, it mostly depends on the thermal conductivity and the undisturbed temperatures of the ground. The GRETA Project funded by the EU Interreg Program Alpine Space aims to produce maps of the geothermal potential in pilot areas across the Alpine territory to identify the most suitable areas for shallow geothermal installations. This paper presents the case study of the Aosta Valley, where the recently developed G.POT (Geothermal POTential) method was adopted. It describes the data sources used and the assumptions made to derive input parameters (ground thermal properties, usage profile, etc.). In addition, the results of a survey on existing geothermal installations are presented.