a solar EV
A Tesla Model X with a Colorado solar vanity plate. [Photo by Christof Demont-Heinrich]

How many solar panels does it take to charge an electric car?

Solar panels on a home in Colorado.
Home solar + an electric car will save you a lot in fuel costs!

blog logoYou actually don’t need that many solar panels on your home, garage etc. to produce enough electricity to fuel your electric car 100 percent with solar.

For many people in relatively sunny places in the United States, six to eight 300-watt solar panels can produce enough electricity to drive your electric car 1,000+ miles per month, which is somewhere around the monthly average for driving in the United States.

Most electric cars get about three to four miles per kWh mileage. To make the math easy, let’s assume your electric car gets four miles per kWh. If you drive 1,000 miles per month, you need a solar system that produces, on average, 250 kWh of electricity per month, 1,000 divided by 4 = 250 (kWh).

A current (2018) six to eight panel rooftop solar system = roughly 1.8 kW to 2.4 kW total.

Let’s take a 2 kW system, which would be kind of in the middle of those two solar system outputs. In Denver, Colo., where I live, a 2 kW system produces about 3,100 kWh of electricity per year, or about 258 kWh per month on average. That is essentially exactly the amount of electricity you need to drive an electric car such as a Nissan LEAF, Chevy Bolt or Tesla Model 3 1,000 miles per month, assuming an average mileage of four miles per kWh.

You would need a slightly larger rooftop solar system in Seattle, and a slightly smaller system in Phoenix, to produce enough electricity to Drive Your Electric Car on Sunshine and generate thousands of Sun Miles®  every year!

According to news.energyusage.com, a 2 kW rooftop solar system ranges in cost from a low of about $3,000 to a high of $5,400 in New York State (those are post Federal Tax Credit numbers, meaning they reflect a 30 percent tax credit).

Considering the average American spends $2,000 in gasoline costs per year, $3,000 to $5,000 for a home “gas station” isn’t much.

You’ll start saving on fuel costs after about two to three years in most places in the United States AND you won’t pay at all for your fuel for the next 18 to 20 years (which is about how long you can expect your rooftop solar system to last). That’s $40,000 in gasoline savings across 20 years — and that is assuming the cost of gas in 2018 does not go up for the next 20 years!