I suspect Tesla has data that for most cars, 400kWh per year is more charging they would need.
We've had our P85 for 4 years, and except for the last year when we took a 2500+ mile road trip, I'm guessing we used less than 400kWh for the other years - because the road trips were short enough that most of the charge we used was from overnight charging (home or destination chargers) and not from the superchargers.
If most owners use less than 400kWh per year, hopefully they will allow credits to carryover - so that owners could "save up" credits to use for later road trips.
We've had our P85 for 4 years, and except for the last year when we took a 2500+ mile road trip, I'm guessing we used less than 400kWh for the other years - because the road trips were short enough that most of the charge we used was from overnight charging (home or destination chargers) and not from the superchargers.
If most owners use less than 400kWh per year, hopefully they will allow credits to carryover - so that owners could "save up" credits to use for later road trips.