Charging an EV with Solar Panels – NerdWallet

You can charge an electric vehicle (EV) with solar panels if you have a Level 1 or Level 2 charger in your home. It often costs less than filling the tank with gas. However, you have to acquire and install the solar panels on your home’s roof first.

How can I charge my EV from my solar panels?

There are two ways to charge your EV with solar panels.

1. Use a Level 1 charger with a regular electrical outlet. A Level 1 charger is a cable that usually comes with your EV and plugs into an electrical outlet. Charging this way can take 40–50+ hours to go from empty to 80%, so the hours when your roof’s solar panels are producing energy will not be enough to fully charge your car; you’ll need to use electricity from the grid as well^[0]

2. Use a Level 2 charger. You can have a Level 2 EV charger installed to power your car more quickly. These chargers can be programmed to charge your car at times when electricity is cheaper and/or when your solar panels are producing the most (you may also be able to schedule this directly from your car). Plus, they can charge your car from empty to 80% in four to 10 hours. So with a Level 2 charger, you can probably charge your car exclusively with solar.

If you pair your solar panels with a solar battery, you solar power for use at a later time. That will extend the times when you can charge your EV with solar energy.

How much does it cost to charge an EV at home with solar panels?

Charging your EV directly from your solar panels may cost less than charging it with electricity from the power grid. That’s because solar may lower your electric bills, reducing the price you pay per kilowatt-hour (kWh).

How much it costs to charge an EV with solar varies depending on these factors:

• Your charger type. The more efficient your EV charger is, the less energy you lose when charging your car and the more you may save. It usually costs less to charge your car with a more-efficient Level 2 charger than with a less-efficient Level 1 charger, and you’re more likely to be able to charge your EV exclusively with solar power^[0]

• The cost of your solar panels. If you own your system and have already recouped the cost of your solar panels from savings on your electricity bills, charging your EV with your solar panels could cost almost nothing. If you lease your panels or are paying back a solar loan for them, your lease or loan payments will affect how much it costs to charge your EV.

• Your EV battery. If your car’s battery has a higher capacity, which means a longer mileage range, it will probably cost more to fully charge your EV. But the cost per kWh probably won’t be higher.

• Where you live. Your savings will be maximized if you live in an area with plenty of sunshine and favorable solar policies. 

• When you charge your EV. Costs will depend on your local electricity rates and plan structures, as well as whether your solar panels are producing energy at the time you’re charging your EV.

• How much you drive. Driving a lot will increase your annual costs — but your savings (compared to filling up a gas tank or even charging an EV without solar) will be higher.

How to calculate the cost of charging an EV with solar power

Because so many variables are involved, it’s challenging to determine what it will cost to charge your EV with solar. But you can get an estimate using this formula:

• Your electricity cost with solar: This is where the calculation gets tricky. If you know your levelized cost of energy (LCOE), you can use that. LCOE is simply your system’s lifetime costs divided by its energy production. If you don’t know your LCOE, you can use what you’re currently paying for electricity per kWh — which might be close to zero if you’ve paid off your solar^[0]

Example: A 2023 Chevy Bolt consumes 28 kWh per 100 miles. If your cost of energy without solar is $0.17 per kWh (the average U.S. electricity price in August 2024 according to the U.S. Energy Information Administration), you pay $4.76 for every 100 miles of range. If your cost of energy with solar goes down to $0.10 per kWh, you’ll pay $2.80 to add 100 miles of range. This might be significantly cheaper than buying the gasoline required to drive 100 miles.

How many solar panels do I need to charge an EV?

Charging an EV typically requires seven to 12 solar panels, according to EnergySage, a solar and home energy product comparison marketplace^[0]

The exact number of panels you’ll need for your EV depends on your EV battery, the amount of sunshine where you live, whether you’ll do all your charging at home and how much you drive.

How to calculate the number of solar panels you need

Use this formula to determine how many solar panels you need.

According to the Department of Energy, today’s EVs consume about 25-40 kWh per 100 miles^[0]

Are solar panels worth it with an EV?

Solar and EVs often pair well. When deciding whether this combination makes sense for you, consider these pros and cons.

• Savings. You can maximize your fuel savings by charging your EV with solar.

• Emissions reductions. EVs produce fewer emissions than gas cars even when powered by electricity from the grid; you’ll lower your emissions further by powering your EV with solar.

• Potential increased reliability. If you pair your panels with a solar battery, you’ll still be able to charge your car during blackouts.

• Grid balancing. By charging your EV with your solar, you’ll help avoid strain on the power grid as demand for electricity increases.