So, i have an idea thats only really worthwhile for people who work/are out and about when its darker out:
Buy cheap solar panels, wire them to a MPPT charge controller, hook that charge controller up to your car during the best solar energy hours. Size the system according to how big your car battery is.
This sort of system would use most of the solar panels ability to produce solar energy, and you wouldnt need to purchase extremely expensive inverters/grid tie in stuff or even talk to the power company.
Example:
Car with 10kwh battery; depleted on average to 30% leaves 7kwh needed to charge.
In florida, theres about 4.5 hours of useful sun, so i would need 7/4.5 = 1555w of solar panels PTC rate (usually around 87-94% of STC rate): So translated.... I would need most likely 10 185w solar panels & a charge controller capable of accepting around 250v...For example these:
Sun 185 Watt Solar Panel
Midnite, Classic 250, MPPT Charge Controller
So cost:
221*10 panels
721*1 controller
mounting brackets for the panels..not sure probably ??
combiner box + fuses, another ??
4/0 wire as needed ??
interconnecting wires as needed ??
So cost is 2931 + misc; probably adds up to 3.5k or so.
Estimated pay off:
3500$/{(7kw/day)*(13c/kwh)*250days/year} = 15.4 years
So it pays for itself a little bit faster than if i did a grid tie in system which typically pay off themselves in 20-25 years.