The Copernicus project ENSURE is developing the power grid of the future. In eight communities in Schleswig-Holstein, the project wants to build up this future grid on a test basis in the coming years. In order to do so, however, the project must first know what the future looks like whose grid it is developing. To this end, ENSURE has developed four possible storylines by 2019 on what Germany’s energy supply could look like in 2030. On the basis of these storylines, this ENSURE study examines how much centralized and how much decentralized power supply makes sense from a technical and economic perspective – and is socially accepted. The result: no matter which of the four storylines is politically pursued in the coming years – there is always a need for expansion at both the central and decentralised levels of the electricity system. In contrast to previous studies, the ENSURE analysis takes into account various future scenarios as well as parameters relating to market, network and information and communication technology infrastructure. It also includes data on final energy consumption, primary energy use, energy conversion and energy storage.