Solar Panels + an Electric Car: Do They Pay Off Together?

If you drive an electric car, solar gets a lot more attractive. Charging from your own panels can turn expensive grid electricity — or gasoline — into near-free miles. Here’s the math.

How much extra electricity an EV needs

A typical EV uses about 0.3 kWh per mile. So:

• 10,000 miles/year ≈ 3,000 kWh/year of extra electricity.
• 15,000 miles/year ≈ 4,500 kWh/year.

That’s a big jump — often 25–40% more than a home’s normal usage.

How many extra panels that is

Using the sizing logic from our panel size guide, covering 3,000–4,500 kWh/year takes roughly 2–4 kW of extra solar, or about 5–10 more panels depending on your sun. The Solar Panel Size Calculator can size the whole load if you add your EV usage to your home usage.

Why solar + EV is a strong combo

• You replace gasoline with sunlight. Home solar electricity is far cheaper per mile than gas.
• Better use of your own production. Charging the car during the day soaks up midday solar you might otherwise export cheaply — especially useful with weak net metering.
• One bigger install is cheaper per watt than adding panels later, so size for the EV now if you’ll get one soon.

Practical tips

• Charge during the day when possible to use solar directly.
• Consider a time-of-use rate so any grid charging happens off-peak.
• If you can’t charge during the day, a battery lets you store solar to charge at night.

Bottom line

An EV roughly adds a quarter to a third to your electricity needs — plan for a few extra panels and solar becomes a two-for-one win on both your power bill and your fuel cost. Estimate the combined system with the Solar Savings Calculator.

Educational estimates only. EV efficiency and driving habits vary.