Germany will produce all its base load in 15 years by wind.
No idea how you come to the brain dead idea that base load is produced by dispatch able plants. It is not.
Base load is produced by plants that never change their output (because historically, that was the cheapest plant thinkable). In future you use wind for that. The load following plants don't care if they follow the changing demand (with fixed load nuclear/brown coal plants) or changing base load wind plants or both. It is the same 'problem'.
With enough wind plants distributed over the whole country and the use of forecasts/prognosis there is no additional problem involved.
However, perhaps you live in a different universe and your