It is indeed a problem, however just for a few days in the year, most of the winter there's no issue. From your link:
> The German weather service estimates that it happens on the average twice each year, that the power production from wind and solar in Germany is less than 10% the expected average for at least 2 days. Every once in a while these situations can last a week or longer.
> The German weather service estimates that it happens on the average twice each year, that the power production from wind and solar in Germany is less than 10% the expected average for at least 2 days. Every once in a while these situations can last a week or longer.