La diffusione dei sistemi solari in Italia e la nascita di una cultura della sostenibilità energetica. Una proposta di lettura - The energy crisis is among the main challenges that people will have to solve in the next years. Unsustainability of the current production consumption energy model is evident. The spreading of solar system (for example Photovoltaic system) is among the basic social phenomena for the birth of a new energetic culture. After Germany and Spain, nowadays also in Italy there is a boom of transfer of solar technology for domestic use. This paper, after a brief history of energy system and a discussion on a few normative and technical issues, proposes a sociological interpretation of this social phenomenon. In particular it studies the social reasons for the actions of the people who choose solar technology.