school energy&environment

Our local system

Italy, because of its geological situation, is rich in both high- and low-temperature geothermal fields. The “symbol” and flagship of the geothermal energy in our country is definitely represented by the Larderello-Travale-Radicondoli thermal field, in Tuscany. Here electricity was produced for the first time in the world, but the exploitation of the “soffiones” goes back to the Middle Ages, for the production of sulphur and sulphuric acid, and, from 1780 onwards, for the production of boric acid. If the resource is entirely Italian, the first use of thermal energy for boric acid extraction was enacted by a Frenchman, Mr. De Larderel (who gave the name to the place), since the vapours of the soffiones are rich in boric acid. The first experiments of electricity production took place in 1904 and the first production plant was born in 1913, with a capacity of 250 kW, but it was only since 1930 that electricity production became an important part of the renewable energy sources of our country. With a capacity of 790 MW, exactly 100 years after the first experiments, geothermal energy in Italy reached in 2011 its maximum productivity level, with a production of 5300 GWh, net of consumption of auxiliaries. Research in this field hasn’t yet stopped: currently a 3D seismic prospecting is being realised, associated to the perforation of 11 new deep wells (of between 3.000 and 4.000 m of depth): in the last 5 years, a total of 21 wells has been realised, with an overall length of 64 km! The second “historic” Italian geothermal field is situated not far from Larderello, on M. Amiata, where electricity is produced by an 88 MW plant. Apart from electricity production, the Tuscan plants provide water for domestic and greenhouse heating, for dairy production and fish farming and fuel the production of  CO₂ and boric acid. Recently other interesting fields have been discovered in Lazio (Alfina e Cesano) and in the Campi Flegrei area (Napoli), apart from the Colli Euganei area (Veneto) and around Ferrara. Fields of hot water have been discovered in the Pianura Padana subsoil, at S. Donato Milanese (Lombardia), between 1900 and 2400 m, with temperatures between 70 and 80 °C, and similar fields have been detected in the subsoil of Villaverla and Vicenza (Veneto) and Ferrara (Emilia Romagna). In the subsoil of the Casaglia area (Ferrara), where carbonated aquifers with a temperature of 100° C have been found at 1200-2000 m of depth, one of the most important projects of geothermal district heating in the world is being realised, which entails the heating of tens of thousands of houses.