Techno-Economic Mapping for the Improvement of Shallow Geothermal Management in Southern Switzerland

Abstract

Cantone Ticino, a mountainous region located in the southern part of Switzerland, is greatly affected by the continuous growth of subsurface exploitation through the use of both closed-loop and open-loop geothermal systems. In this study, techno-economic maps for shallow geothermal potential of Cantone Ticino are produced, considering closed-loop systems. The work starts with the identification of the main parameters affecting the techno-economic potential such as GST and thermal conductivity. Maps for different indicators of techno-economic feasibility are created and compared against real data/measurements. An empirical method is tailored to derive a map of the techno-economic geothermal potential, expressed as meters required to provide 1 kW of installed power. The produced map shows an overall discrepancy from real installed length data of approximately ±23%. Moreover, compared with current regulation, the produced maps show an unoptimized management of the shallow geothermal resource, since high potential zones are commonly located where the installation of BHE is not permitted and often closed-loop systems are installed where the estimated potential is lower, mainly in alluvial fans. In light of these considerations, the authorization process in Cantone Ticino for BHE should be revised taking into account the real techno-economic potential.