On the other hand an advantage that solar and wind have is that they are predictable in the medium term. Weather forecasts are fairly reliable predictors of solar & wind output about a week or so out. They also ramp up and down smoothly.

So while grid operators have to be constantly adjusting for solar & wind output variations, they can do so without panic and without customers noticing.

Reactor shutdowns, while rare, are sometimes very unexpected and drop a lot of capacity from the grid very quickly.