Impact of the German nuclear phase-out on Europe's electricity generation

The combination of the ambitious German greenhouse gas (GHG) reduction goals in the power sector and the nuclear phase-out raises many questions concerning the operational security of the German electricity generation system. This paper focusses on the technical feasibility of the German nuclear phase-out on the short term (2012-2022) and on a European scale. A detailed electricity generation simulation model is employed to address the issues at hand, including the German transmission grid and its international connections. Power plants are modelled with a high level of technical detail. A range of different renewable energy sources (RES) scenarios is considered. Results are presented for the change in generation mix, on the flows in the electric network and on operational reliability issues. The simulations show that the nuclear generation will be replaced mainly by coal and lignite based generation. Furthermore, the results indicate that export in 2012 on high demand - low and medium RES infeed days will be problematic. Keeping the seven oldest nuclear power plants (NPPs) online, would mitigate this for days with medium RES infeed. If the capacity that is currently licensed is built before 2017, the situation improves. However, the situation on the northern part of the transmission grid stays critical. In 2022, the assumed extension of the generation capacity will not suffice. Keeping the NPPs due to shut down after 2017 on line would mitigate these contingencies.