Territorial mapping for the exploitation of low-enthalpy geothermal resources

As is well known, a sustainable development of every Country must face the energy problem. Generally speaking, not only energy consumption has to be reduced but also traditional energy sources has to be gradually replaced by environment friendly ones. Among the renewable energy sources, a particular interest is due to 'low-enthalpy geothermal resources' that allow an advantageous use of heat pumps for winter heating. A correct exploitation of these resources relies on the existence of a general criterion for the choice of the best locations where GCHPs can be successfully installed from the point of view of the payback period length. In the present paper, a method to compare different sites and choose the suitable ones is proposed by taking into account some quantities of the site under consideration, including the Heating Degree Days and the average temperature of the ground. As an example, this method, which has been setup by considering the available data for all the Italian municipalities, is applied to the provinces of Bologna and Genova.