Together with ef.Ruhr, EWI investigated the development of frequency stability in Germany on behalf of Siemens AG. With the help of the European electricity market model DIMENSION, the power plant parks of two scenarios were optimized for the year 2040. The first scenario exclusively depicts the German coal phase-out, while the second scenario additionally assumes that the European countries with a high proportion of conventional power generation will make a change towards renewable energies. As indicators for the frequency stability of the resulting systems, ef.Ruhr uses a point model to determine the frequency gradients, grid start-up time constants and dynamic frequency minima.
The analyses carried out show that there is a need for action in order to be able to guarantee the frequency stability of the energy supply system in the year 2040 without restrictions. The decrease of the instantaneous reserve due to decreasing energy from conventional power plants results in the shortfall of the permissible frequency minima as well as in a critical increase of the frequency gradients, which can cause critical system states in each case. An increase in the instantaneous reserve or an acceleration of the primary control power can guarantee frequency stability.