Elena ``of Valhalla''
@jwildeboer eh, to be fair both things are true at the same time
if at any single minute (or even second) you have more production on the grid than consumption and you're out of
- batteries (and other storage) that can still be recharged
- factories and other big consumers that can increase their use of energy on demand when there is more of it available (and thus cheaper)
- private customers with smart homes that can run things like their AC now and store that energy as air temperature for later (or water heaters, etc.) then you do need to shut down some renewable plants, otherwise things will end up in blackouts and/or fires.
But also, it's perfectly fine! Especially solar panels that don't have big moving parts can do so basically instantaneously, without suffering any consequence (and wind and hydro require just a few minutes to bring their big chunks of spinning metal to a halt). True, some energy will be wasted, but then a lot of light from the sun is hitting built surfaces that don't have solar panels on them, and that's also wasted, isn't it?
On the other hand, if you have to do so more often than “now and then”, (and you still have times when energy is scarce), then on a longer time scale it's time to build more (and more. and MOAR) of the above things, so that the basically free energy can be put to a good use.