Since its foundation, the Wuppertal Institute has been working on visions for a sustainable and low-CO2 society. Based on the goal of reducing greenhouse gas emissions in Germany by 80 percent by 2050, the Wuppertal Institute has developed various long-term scenarios for the German energy system. They serve as a basis for the long-term energy study of the German government and also the climate protection policies of municipalities strategies towards the long-term goal of a low-carbon society. A study commissioned by Siemens AG for the city of Munich shows what this could look like. Long-term energy scenarios, such as those developed by the Wuppertal Institute together with research partners for the German Federal Ministry of the Environment, contributed to the German government's decision after the Fukushima reactor accident to abandon nuclear power generation and initiate the energy turnaround.