Storage is actually under-rated.
The other problems of creating a grid sufficient to meet country wide needs are also underrated.
Indeed, these problems are virtually hand-waived away by most, with the blithe assertion that the sun is shining and the wind is blowing somewhere. These folks never look at maps, and fail to notice that the earth is 3/4 covered with oceans.
Hydro works because of storage. Coal works because of storage. Nuclear works because of storage. You can spool these up when needed, and throttle them back when not needed, storing the fuel for later.
Wind and solar have a big problem, not because of grid technology, but simply because of lack of storage.
Well, you could use wind and solar power to pump water from one spot to another further up the hill as energy storage and release it as hydro energy. Granted, this adds inefficiencies to the model, but it is one way to store energy. Until we figure this out, though, I am pro nuclear...