Lets say its May 5th 2017 11am in Germany and there is about 59GW of demand to keep the country functioning and you are a greenie looking forward to a day when there is no more nuclear or CO2 producing power plants..
Ooops. 0.17GW from solar. 3.37GW from wind.
7.7GW from nuclear.
42GW from CO2 producing power plants (gas, coal, biomass, oil)