Solar and Wind vary on both a diurnal and seasonal basis. It is one thing for the grid to have enough storage.
I was looking at this paper
https://www.eia.gov/analysis/studies/powerplants/capitalcost...
where solar is quoted at $1300/kwh and adding a battery that can store a little more than an hour of output brings that to around $1800/kwh. I see people quoting that one like it is gospel but that doesn’t seem to be enough storage. If you assume the system needs 12 hours of storage to get through the night you need 10 of those batteries and the cost is getting into the $3500/kwh range.
They quote the AP-1000 and NuScale around $6000. Solar looks cheaper now and maybe it is in the tropics but in the Northeast you are going to get a lot less power in the winter than summer so to keep the lights on all year you might need two of those solar installations (though I think the battery stays the same) and now you are getting around $5000/kwh so that gap with nuclear is getting smaller.
That estimate may be a bit pessimistic, but renewable advocates right now sound like the people who were saying nuclear would be “too cheap to meter.”
Now if you have excess capacity in the summer you could in principle use it for something but that is not trivial. If you use something half he year you basically double the capital cost. Do you hire workers to do nothing in the winter or do you lay them off? “Free” excess solar energy might be “free as in puppy” not “free as in beer.”