A/C: It doesnt have to run the AC per se, even if it just circulated air via a fan it would be fine. But I can see this being fairly complicated. Battery Charge: This however seems pretty straight forward and simple. Starting with a full battery would extend the amount of EV range, which would increase the efficiency, also it would give some free charge while driving. The only thing that would be needed to charge the battery are the panels and the power management connected to the batteries. That should not be very different from what is in an "off the grid" house, but scaled down. The panels are not that expensive, the flexible peel and stick kind sold on amazon, 250 sf, for about $300. That's much bigger than the area of the Fusion roof. I think its doable and affordable.