That's incorrect. While Germany failed to make its reduction goals, it still reduced emissions while simultaneously increasing production.
Do you have a source for that claim? Keep in mind that there are also renewable energy sources that do not rely on weather events (water and biomass).
In combination with energy storing and a reduction of the total energy needed it is afaik considered possible to go fully renewable [1].
[1] https://en.wikipedia.org/wiki/100%25_renewable_energy
EDIT: I misread your comment. I thought you were arguing that "unclean" power plants are nessecary. However my point about not needing nuclear still stands.
Varying power sources need to be combined with adjustable power sources. So do constant sources, unless you want to force consumption to correspond to availability. Shutting off nuclear plants and going fully renewable would require bringing more adjustable sources online, though. Hence the quest for better storage technologies.