Comment by VBprogrammer

They get turned off to avoid damage in too much wind, not to avoid overproduction. We only have a few GW of installed solar capacity so it's not hugely important to the overall picture.

In the UK it's easy to see that Wind and CCGT plants operate in inverse of one another, when it's windy most of our power comes from the wind and the CCGT are switched off. And conversely when it's calm the CCGTs produce most of the power.