L'energia geotermica sfrutta le forze endogene presenti nel sottosuolo di regioni caratterizzate da una geologia favorevole, per la produzione prevalente di energia elettrica. Il principio si fonda sullo sfruttamento di potenti getti di vapore acqueo ad alta temperatura che vengono liberati attraverso la perforazione di spessi strati rocciosi che li imprigionano. Il fenomeno avviene generalmente in corrispondenza di regioni vulcaniche, perchè qui è maggiore la possibilità di incontrare rocce ad alta temperatura ed a modesta profondità

 

The most important geotermic Italy is placed in Larderello, Tuscany. This geotermic region, is located in the belt of the Tuscan Pre Appennines, respectivenly separated by Cecina River and Flora River. Morfologically, the area is represented by hills and low mountains, with peaks controlled by erosive process. The higher mountains rigdes, also represent tectonic highs from era. In the region, in late Tertiary and Quaternary, a complex post orogenic vulcanic phenomena occurred.

 

Here the magmatism is evidenced by widespread volcanic activity leading to the effusion of generally acid lavas and ignimbites. Later a basic sequence in vulcanic rock had place and covered the older magmatic rocks. The rigid dislocations related to both the post orogenic collapse, and the vulcanotectonics of considerable importance in the structural framework of the region. Also there is a marked thermal anomaly in the central part of the region, especially close to the southern edge of the volcanic massif. The geothermal gradient is generally higher.