Ever wonder how many solar panels you would need to charge an electric car? The answer is “8 to 10 panels (or around 2.5kW).” Your next thought might be “how much would it cost?” You can get a 2.5kW system delivered to your house for around $4,400 (see mrsolar.com snip below). Your home system is eligible for a 30% tax credit which should roughly cover the installation cost. The panels will last 25 years or more and the inverter will probably need to be replaced at least once. All in, let’s call it an even $6,000 for 25 years of fuel for your car.
Just for fun, divide $6,000 by 300 months (25 years) then say this out loud “Solar power is too expensive. I won’t pay $20 per month to fuel my car for 25 years directly from sunshine.” Hopefully your kids just looked at you like you are crazy. Do I have your attention? Please read on.
Now the details: most electric cars will travel 3 miles per kWh. In the desert southwest, a south facing 2.5kW solar system will produce roughly 4,000 kWh per year (PVWatts will show you this here). That is enough energy to drive 12,000 miles.
There are a few other details. Your utility needs to allow net metering at the full retail rate – and hopefully they do. As explained in detail here, when the car consumes the same amount of energy that the solar system generates, it becomes a win-win for everyone. This is important and I’ll write about this in more detail in a coming post.
And yes, we have 5.5kW on our rooftop – with 2 electric cars. Our cars are powered from sunlight.
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