The turnaround in energy policy is meant to lead away from the old system of centralised power stations, from the conventional energy sources such as coal, oil or nuclear power. Instead, energy is to be generated in a lot of smaller installations from renewable sources such as sun or wind. That leads to a new structure of energy supply. The turnaround requires a new, intelligent system with which the energy exchange between generator and consumer will be controlled in the future. The English term “smart grid“, which translated means nothing other than ’intelligent electricity network’, represents this system of the future.