To avoid looking like more of an idiot, I went back and found the official DC Fast Charge levels and wattages (level 3 DC fast charge is up to 350kW, level 2 is up to around 18kW). Which, thankfully, didn't change my conclusions above, I was of a more sound mind when I did those calculations before.
But here they are again.
Level 2, at 18kW, would be around 157,680 kWh/y per charger at full utilization. (18*24*365)
Level 3 would max out at 3,065,000 kWh/y per charger; but it's much more likely to be intermittently used. (350*24*365)
There are exactly zero cars on the road today that won't be 100% full from 0.1% battery in under 24 hours when plugged in to a Level 2 charger.
Depending on the car's internal charger (1 or 3 phase) most charge from "towed to charger" empty to absolutely full in well under 10 hours.
Doing it like that is like trying to calculate how many fuel trucks would a gas station need if all its pumps were being run 24/7/365 at full blast. It'll never ever happen.
That's more related to the the calculation from my statement a bit back up the comment tree:
> it was about 43,000 GWh/y for CA (15m cars * .24 KWh/m * 12,000 annual miles). For reference CA has a yearly electricity generation capacity of just under 200k GWH/y.
But the numbers I posted that you're directly referring to are still important, as they indicate the need for improved electrical infrastructure for individual buildings who may want to put in chargers. Your grocery stores, apartments, motels, etc.
If just one 18kW charger can double demand on a motel's power, what happens when you add ten? Twenty?
