The department collection is spread out, due to size and functions, from the Museum entrance to outside areas. Indeed it includes complete plants, both historic and modern, such as the Regina Margherita thermoelectric power station (1895) and a photovoltaic field linked to the network. The hall located on floor -1 of the Monumental Building has the task of offering an overview of the energy system and of its evolution, due to governments directives and development programmes, but also to ideals and initiatives by the single person. Starting from sources, grids, networks and consumers -the “things” of which the energy system is made up of- the exhibition shows and analyzes some changes connected with the evolution of the energy system: some of them have already come into our homes, others involve Italy, Europe and the entire World. A central role is given to energy forecasts for the future and to the jungle of different opinions that surrounds change to the energy system.