But retail prices of carrots don’t increase dramatically from 4-9pm.
I suppose you hope it's relevant because, "the solar power comes just when they need it the most" ?
They don't seem to do the math quite so happily, though. Maybe it's #1 and #2:
First, Safeway buys in very large lots from certified suppliers, who can commit to (almost) always having carrots.
Second, those suppliers have to deliver at a loading dock, and maybe at a central location, too.
> SEASONAL PRICING The cost of electricity on your rate plan is lower during the cooler months from October to May, and is higher during the warmer months from June to September. For full seasonal pricing details, visit pge.com/tariffs. [0]
And here’s a an infographic [1] showing the differences between two plans for season, time of day, and baseline allowance (tiered usage).
[0] https://www.pge.com/pge_global/common/pdfs/rate-plans/rate-p... [1] https://www.pge.com/pge_global/common/pdfs/rate-plans/how-ra...