If the system is able to offset the cost of charging the vehicle, it'll easily pay for itself because my power company implemented a substantial rate hike once you go over a certain amount of KWH usage per month.
I don't care if the batteries supplement the house and that offsets the car, or...
I have an EV with a ~150kwh battery and a PHEV with a ~20kwh battery and the normal use-case is charging 20-50% every couple days for the EV and every night for the PHEV. I'd love to figure out a way to have a solar system that could sustain both charging and possibly provide supplemental power...