As early as 2010, "too much inflexible base load" from coal and nuclear power plants was already clogging up the electricity grid. There was also no negative effect on the electricity price. At the same time, they are less dependent on imported raw materials such as Russian gas.
Solar and wind plant were sometimes unable to generate into the grid, but that was because the nuclear was already providing the requisite demand!
You
could, technically
, reduce power from the nuclear stations if you wanted to. The issue is that it is economically pointless to do so.
The marginal cost of running a nuclear power plant you already have is essentially zero.
Reducing output is economically equivalent to turning on a bunch of fan heaters outside the station.
The curtailed electricity generation has a marginal value of zero, since they could no find anyone to sell it to. I'd suggest a far more sensible solution to this problem is to install grid controlled heating loads for
hot water or industry, which would allow that surplus electricity to at least displace gas. Not order the elimination of several gigawatts of proven very low carbon generating plant.
On electricity prices, Germany has the
second highest electricity price in the EU, after only Ireland. They are double what they are in France.
And, finally, as of 1AM (London Time) 23/06/2024, Germany is pulling 7.5GW of French electricity across the border, French electricity that is currently overwhelmingly nuclear.
German progress is underwritten by French, Czech and Swedish nuclear and in being able to offload piles of surplus electricity to the rest of Europe. As decarbonisation progresses this strategy will become less and less tenable because there will be increasingly no fossil plant to displace.
However, this is rather off the topic of the thread, which is not about the German electricity system!