How many solar panels do you need to charge an electric car?

Imagine having a fully-fueled car... without ever having to pay for fuel. It’s not a pipe dream—it’s completely possible with solar panels and an electric vehicle. No trips to the gas station, no fluctuating fuel or electricity prices, just clean energy flowing from your solar panels to your car.

Electric vehicles (EVs) and solar panels are an increasingly popular dynamic duo that puts money back in your pocket and lessens fossil fuel emissions. With both technologies becoming more affordable, you might reasonably ask how many solar panels you need to charge your EV.

The simple answer? It usually takes 5-10 solar panels to charge an EV. But it depends on the make and model of your vehicle, the weather, and your driving habits. Here's a quick breakdown to help determine how many solar panels you need to power your EV reliably.

First, think about how you use your EV and how much electricity it takes to support it. You can look at it in two ways: how much power it needs for a full charge and how much it uses per mile—usually measured in kilowatt-hours per 100 miles (kWh/100mi).

Your EV’s battery size tells you roughly how much electricity it takes to “fill the tank.” Most EV batteries hold between 25 and 100+ kWh, which is pretty large. For comparison, the Tesla Powerwall 3, the most popular home battery on EnergySage, stores 13.5 kWh of electricity.

Battery size & range of popular EVs

That depends how far you tend to drive. Your needs will be different if you live in an urban area and drive infrequently versus having a long commute every day.

According to Kelly Blue Book, the average American travels about 12,200 miles annually. At that level of driving, most EVs will require around 3,000 to 5,000 kWh of electricity per year to operate.

Annual electricity usage of popular EV models

To calculate the number of solar panels required to power your EV, you'll need to know three key data points: 

1. How much electricity your car uses annually 

2. The total wattage of the solar panels you plan to install 

3. The production ratio of your panels, or how well solar panels produce electricity where you live

Once you understand these numbers, you can plug them into the following equation:

Number of panels = system size/production ratio/panel wattage

Let's do the math for the average American driver:

• A typical EV requires about 3,000 to 5,000 kWh of electricity per year..

• According to the most recent EnergySage Intel Report, 440 to 450-watt panels are the most frequently quoted solar panels on EnergySage. We'll use 450 W panels for this example.

• Production ratios in the U.S. are usually between 1.1 and 1.6, depending on the region; solar panels usually produce more electricity in sunnier climates.

Number of panels = 3,000-5,000 kWh / 1.1-1.6 / 450 W

Based on this example, charging an electric vehicle will typically require 5-10 solar panels.

Number of solar panels required to charge popular EVs

Transitioning to an electric vehicle has many benefits in itself, but charging your EV with solar panels takes those financial and environmental benefits a step further.

Charging your EV with solar will save you money

The savings become even more dramatic when you add solar panels to the equation. Solar-powered EV charging cuts your costs by as much as 60% compared to grid electricity. Here's how the annual fueling costs compare for a typical sedan driving 12,200:

• Home charging with solar: $0, if your system is sized to cover your EV charging

• Home charging without solar: $589

• Public charging: $1,234 per year

• Gas vehicle: $1,365 per year

Over 25 years, charging an EV sedan with solar can save drivers more than $14,000 compared to charging at home without solar, and over $34,000 compared to gas. The savings quickly add up.

Plus, solar offers price stability. While residential electricity prices have risen about 2.8% annually and gas about 3.1% annually over the past decade, solar owners lock in steady, predictable energy costs for decades.

Charging your EV with solar shrinks your carbon footprint

Charging your EV with solar energy vs. grid electricity is better for the planet. Much of the U.S. power grid still relies on fossil fuels. Using clean, renewable energy from your home solar panels cuts your carbon footprint, reduces your demand on utilities, and helps improve air quality.

The beauty of pairing solar with an EV is that both technologies get better together. Your solar panels don't just charge your car—they change the economics of driving electric. Charging an EV from the grid already costs less than filling up a gas tank, but when you generate that electricity yourself, you're driving on sunshine. Once you break even on your solar panel system, every mile is free.

You don't need to cover every mile you drive with solar. Even if your panels only offset 70% of your EV's charging needs, you're still dramatically cutting both your costs and carbon footprint compared to any gas-powered alternative. The key is sizing your system correctly from the start. If you're already considering solar, now's the time to factor in EV charging—even if you haven't bought the car yet. It's far easier (and cheaper) to install enough capacity upfront than to expand your system later.