Monitoring of a Borehole Thermal Energy Storage System Using 2D and 3D Resistivity Surveys in an Highly Urbanized Area

A field scale Borehole Thermal Energy Storage (BTES) test site has been recently built up in Grugliasco (Torino, Italy), in the campus of the Scuola di Agraria e Medicina Veterinaria of the Torino University in an highly urbanized area. This paper is focused to report the results of 2D and 3D electrical resistivity surveys executed on site to evaluate the potentiality of electrical resistivity, to monitor thermal variations within the underground for similar energy storage applications which are boceming more and more diffuse. In this context correct monitoring strategies appear to be of major importance to better understand thermal exchange processes and their environmental effects, particularly into high populated areas. Classic monitoring strategies often rely on local and point-based measurements to detect changes in temperature. In this context, geophysics can bring complementary information which is spatially distributed and acquired directly from the ground surface. Correct acquisition, elaboration and interpretation of resistivity surveys is however very challenging, particularly in highly populated areas where these kind of applications are usually designed.