Can solar panels charge an electric car?

Charging your electric car with solar panels is a great way to save money in the long run. We explain why...

One of the big selling points for electric cars is that they’re environmentally friendly. This is true to a large extent because pure electric vehicles come with no tailpipe emissions that harm the atmosphere.

However, the electricity they require comes from the National Grid, which is still significantly fuelled by coal and gas.

For those who want to improve their carbon footprint and save even more money with their electric or plug-in hybrid cars, it is possible to charge them via solar panels installed on the roof of your home.

How to use solar panels to charge your electric vehicle

If you have solar panels on the roof of your home, or are thinking of installing them, it’s important to note that they cannot actually store electricity. This means that whatever they generate has to be used immediately – either to power devices in your home or sold back to the grid.

To efficiently charge an electric vehicle using solar panels, you will also have to install a home charging unit and a PV inverter unit that converts the solar energy into DC current for the vehicle. There are several of these systems available for purchase already, but no dedicated standalone solar panel car charger is available yet.

The costs aren’t small, though. Depending on which wallbox you buy, prices range from a couple of hundred pounds for the most basic 3kW systems, rising to close to four figures for the most advanced 22kW units.

Solar panels are expensive, too. A 1kW system with four panels taking up eight square metres costs between £1,500 and £3,000. Bigger systems cost more.

A 1kW system is estimated to generate 850kWh of energy output a year: that could fully charge the new Honda e 24 times over, which translates into some 3,250 miles of driving range. If your annual mileage is relatively low, solar panels could be a great long-term solution.

How long does it take to charge an electric car using solar power and what are the savings like?

This obviously depends on the amount of sunlight and the type of panels on your roof, as well as the type of wallbox charger you have. Our sister title Auto Express visited one electric car owner, Warren Philips of Shoreham-on-Sea, who uses solar panels to charge his Renault ZOE. On a sunny day, the panels on his roof can generate upwards of 40kWh of electricity, enough to charge the 40kWh battery in his car.

However, one issue that electric vehicle owners may encounter is the time they charge their cars. Most charging at home happens overnight, when there’s no sun to generate free electricity. This is why it’s worth considering installing a home battery system – like a Tesla Powerwall – to store the solar energy to recharge your car.

Again, this is another added expense, but in the long run the savings will far outweigh the costs. Auto Express reader Warren Philips estimated that he will be £13,000 better off in 20 years' time after installing his solar panels, wallbox charger and Tesla Powerwall.