UTES Capability Evaluation and Mapping

Abstract

During the last decades, the increasing number of co-generation plants and solar thermal system developed worldwide and the needs for more efficient energy use in building and cooling made the employment of Underground Thermal Energy Storage (UTES) systems increasingly interesting. The possibility to store the waste heat and the excessive heat production generated by solar panel, biomass plant, industrial processes in the underground in the warm season to recover it during cold periods, enables energy cost saving and reducing greenhouse emission. However, the thermal efficiency of storage is strictly dependent on the different geological conditions characterizing the territory. Among others, one of the key priorities for the properly assessment of the heat storage suitability in the underground is the knowledge of the thermal properties of rocks and sediments, as heat capacity and thermal conductivity, necessary to quantify the heat storage capability and the potential losses of the system. This paper aims to show the first results related to the thermal characterization of several lithotypes belonging to Eastern Italian Alps. Moreover, an example of subsoil thermal properties mapping through geographical information systems (GIS) is presented. These maps allow to obtain a low enthalpy geothermal cartography and constitutes an important support, suited to real underground conditions, for UTES plants design and for policy makers taking decisions concerning promoting and control diffusion of the shallow geothermal solutions.