Energy market impact of renewable energy source

New energy scenarios see renewable energy is no longer as marginal sources, but as actresses able to change the energy market. The past few years have seen the energy market more fluid than that of past decades, the constant growth of the renewable component of the global energy mix has changed the relationship between offer-demand and also because of the changing geopolitical conditions, there has been a constant reduced costs of fossil fuels. This article intends to put highlight, in Italian, as the market fossil fuels is influenced by the penetration of renewable energy. In addition, by relating the benefits (economic and externalities), obtained from the dissemination of renewable, with the costs for promoting the development of renewable energies.