I did the numbers assuming that PV powers the car directly, therefore, you need 1 kwh from the PV grid per 1 kwh spent by the car.
But that’s not the entire story. Your PV produces most power during the peak hours, and your EV is charged at night. Unless I’m misunderstanding something, you’d have one meter for the house and one meter for the car. Each kwh produced by the PV system knocks off $0.28 off your main electricity bill, but each kwh pumped into the EV battery during super off-peak hours (midnight to 5 a.m.) only costs you $0.145. So a PV system big enough to power the EV would not just make you energy-neutral, it would make money for you.
In the example above (Leaf + 2.5 kW DC of panels) you pay $40k up front, you don’t spend any money on gasoline, and the setup reduces your main electric bill on the order of $400/year.
