That's inaccurate. Germany has replaced half of its _electricity_ production with renewables (modulo dispatchability), but electricity only accounts for a quarter of the energy usage. We frequently have to import electricity from France now, where it's largely made by nuclear, and electricity in France is a lot cheaper than here. Closing the German nuclear plants was grand scale stupid.
We buy sometimes electricity from France on the EEX because it's cheap. Not because we lac electricity. We actually sell more than we buy and that never changed.
France has to sell cheap because they can't shut down their rotting fleet. They HAVE to produce and they HAVE to sell. Even when the price is low. This is just another reason why the company running this hilarious "business" is bankrupt.
Germany has long ago replaced what nuclear has produced.
The only thing we HAVE to buy is gas because we need it for heating. Something nuclear can't replace since we don't even have 5% electrical heating in this country.