Well, already 25% or so of German electricity are renewable, and there is still potential. No, we can't simply switch off all lignite plants (which are worse than coal) and most renewable has a problematic variability, but we're working on it. If you asked me we shouldn't have exited from nuclear as hastily after fukushima.
The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition