The paper describes in a holistic manner the structure of the future energy system according to the targets and the framework of the German “Energiewende”. This system is based on volatile and dispersed renewable energy sources. With respect to the existing infrastructure a fundamental transformation process is required. From a technical point of view, power becomes the dominant factor for the system design. Electrical grids have to be more dynamic and they have to be turned into smart grids. In order to manage volatility, not only electricity has to be considered. As most of the renewable energy sources are generating electricity this energy form will stay the energy hub, however, it has to be integrated into a holistic electricity, gas and heat system. As a consequence a coupling of the industrial, mobility and building sectors will occur. Capital costs are replacing fuel cost. Thus finance becomes a pivotal element. Today’s and future challenges for the energy system are discussed and solutions are proposed. The ongoing transformation process in the energy business shows disruptive characteristics. It is merging with digitalization which is another disruptive mega trend. It turns out that the legal framework that is guiding the transformation process of the system has to be adjusted to the new physical principles. Technology is available in principle and emotions of customers are getting an increasingly important factor.