Seems stunning that you could charge an electric car for 8 months without realizing you're not on a TOU plan.
We've got an EV and rooftop solar, and while I knew it was going to be an arbitrage scheme to begin with (with Net Metering, you don't use your solar to charge your car, you absolutely don't want to charge your car while the sun is shining), it was surprising to me to what extent usage had nothing to do with production. They're 2 entirely different things you treat entirely separately.
I thought I understood NEM2.0 pretty well (here in CA). Instead of the old NEM1.0, where 1kWh of generation = 1kWh of usage credit, it's bucketed by time of day. I actually thought NEM2.0 would be better for us than NEM1.0 -- we have generous peak hours (1pm-7pm) so we generate a TON of electricity off the roof at up to 38c/kWh during the day, and consume most of our power at much lower rates overnight. So 1kWh generated might be worth 2kWh into the car!
What I didn't factor in was that NEM2.0 credits are bucketed by month, and the consequences of that.
Yes, it means we generate very little in the winter, while our usage is just as high as in the summer, but that would wash out over the course of a year.. except for tiering! It hadn't crossed my mind how much tier 2+ usage we'd have in the winter. Which means it actually can pay off to charge the car at work in the winter, while it's pointless in the summer.
We're on a grandfathered TOU plan that I wanted to keep for those generous generation credits, but I'm thinking of moving to an EV plan because the much cheaper charging rates might offset the more-generous peak hour timing and credits. (peak would be 4-9pm though, which means we generate less during peak, and we also use more at peak, since typically we get home around 7pm, all of our evening usage would still be at peak).