AC use largely corresponds with peak solar, though, so it doesn't seem like a particularly tough problem to solve? In California, there's often a surplus of solar energy on hot days.
I think the solar generation from say 10am-4pm is where you'd find a surplus, if there is one.
At least at my home, there's only ~20% difference between peak and off-peak rates, but, if you have A/C, it still makes sense to pre-cool on hot days, back it off at 4pm and then turn it back up at 9pm if you still need the cooler temps to sleep.
1. https://www.caiso.com/content/summer-loads-resources-assessm...
Whereas for winter heating, you would want to preheat a lot, and you would also need an oversized PV array, because there's just way less energy available from the sun.
I’m in the SF bay area, though, so that’s playing on easy mode.
The peak grid demand has slowly been moving later in the day (and year) because home and commerical and industrial solar is displacing grid demand.
https://www.caiso.com/documents/californiaisopeakloadhistory...
People regularly use this solar success to claim solar is useless.