Energy balance of the Italian hydrothermal spa system

After heating and cooling, thermal balneology was in 2010 the second most important sector of direct uses in Italy, with 149 thermal localities using hot water for balneotherapy, with no combination with other direct uses. This is why, in 2009 and 2010, UGI conducted regional studies on their water and energy balance to investigate the possible optimization of the heat consumption by coupling thermal bathing with other upstream and downstream direct uses. Moreover, since two thirds of the spas utilize water in part artificially heated, the studies also evaluated the energy consumption of the heating process and compared the result with the geothermal fraction of the energy used. After an overview of the geological and hydrogeological settings of low-temperature geothermal resources, the paper describes the situation of thermal balneology in Italy at Dec. 2010, estimating the volume of hot water consumed, and the amount of heat used by the overall spa system at the regional and national level. The methodology devised to analyze the various components of the water and energy balance and its conceptual flow diagrams are described in the paper. The paper also reviews the different types of direct uses which, depending on the temperature of the water available upstream (T > 38°C) and downstream (T < 28°C) of the thermal establishments, might be associated with the thermal balneotherapy. Finally, the paper pinpoints the benefits that might arise from the development of multiple uses combined with the thermal balneology, in terms of: i) oil saved; ii) displaced CO2 emissions; iii) higher number of spa users; iv) increased tourist activity in the spa areas; and v) creation of new production activities and jobs in the same areas