Solar generator on PV roof?

I've been toying around with catalogs trying to build a portable solar charging system for my Volt as an academic exercise, in a what if the zombie apocalypse started tomorrow and I really wanted to get across country hypothetical way.

Using equipment currently available on the market I priced out a pack that would fit in the hatchback, weigh about 120 lbs, have capacity to charge and store about 40 miles worth of juice in 2 days, and cost about $13,000. (sort of a very large array of the little fold out panels for consumer electronics, feeding a DC power supply and an inverter to convert to AC for charging the car [has no direct DC to DC charging])

 

As an academic exercise and conversation piece I think a car cover with solar panels on it would be nice. You also would not subject it to the rigors of a car wash. Putting them on the roof seems like a gimic toyota has already done, so you might as well get the sun roof and not charge the battery.


For practical not fun projects, adding that capacity to the battery and the solar elsewhere seems like a better idea. Solar on the house, office, etc will be around for more years we hope and be more efficient. It also has the benefit of giving the grid peak power while charging your car with off peak power. It would be nice if toyota allowed the modular addition of batteries to the phv for those that want to put more solar in their cars

Now there is room in the hatch back to hold a lightweight wind turbine to charge those batteries.

 

Is this what you had in mind?

Solar Electrical Vehicles

 

aaahhh yes, the ol' wind turbine on the car idea. Ford already has a patent on it I believe:
Hybrid and Electric Vehicles » Green Patent Blog®



Yes ... Our tax research dollars - hard at work.


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A few thoughts on this design:

1) With 4 panels you are only at 48v nominal input to the MPPT, which is its minimum. You should get a 5th panel in series to get the voltage up more into the desired range.

2) The 3 groups of panels in distinct locations on the car are likely going to have different light levels and thus, different optimal voltages. Therefore, you don't want to wire OR them together into the same MPPT regulator since it will regulate their combined voltage to a level that is not optimal for any of them. Better to put each on its own MPPT regulator.

3) What do you do with that 48v battery after it has charged up from 2-3 days in the sun? Is there a DC/DC converter somewhere to use it to charge the traction battery?

 

Here in sunny Florida, the rule of thumb for solar installations is 5.5 hours per day of average peak output, so 60 watts x 5.5 hours = 330 Wh a day, or just about enough for 1 mile.

The roof of your house is a much better place for solar panels than the roof of your car. If I lived in Califonia with their much more expensive electricity, especially during the day when solar is operating, I would get some. Here in Florida though, electricity is cheap, so it would take me 13 years worth of saved electric to pay back the up front cost of a $10,000 system, and that is if I buy all the parts wholesale and install it myself. I'm still toying with the idea, but that's a hard cost to justify.