Cars with solar panels

Make the most of the sun's energy to cool your vehicle or recharge its batteries: cars with solar panels

BuyaCar team
Jul 16, 2018

When it’s sat in the sun on a blazing hot day, a car’s roof might seem like an obvious place for a solar panel to gather energy at no cost.

And if you drive an electric car, then that power could be sent straight to the battery to boost your range with free electricity.

The concept is perfect. Unfortunately, that’s more than can be said for the technology. Solar panels covering a car’s roof don’t generate a great deal of electricity, although manufacturers are working on more efficient designs; Audi plans to integrate thin solar cells into panoramic sunroofs.

 

So for now, the handful of cars below, which are available with solar roofs, use the electricity for small battery power boosts or to run a fan and keep the car cool on hot days.

 

Cars with solar panels

Toyota Prius Plug-in (2017-present)

This plug-in hybrid version of the Toyota Prius, works best when its battery is fully charged, enabling it to drive for approximately 30 miles on electric power alone.

So a solar panel covering the roof that can charge the battery while the car is parked sounds like the perfect solution. It also generates electricity while on the move, powering equipment such as air conditioning and sat-nav to reduce load on the battery.

Sadly, fully charging the battery would take ten days, assuming you park your Prius in full sunshine. Living under frequently grey skies, you can expect around 400 miles-worth of charge each year. It doesn’t take much mental arithmetic to realise that this averages out to little more than one mile per day.

Unsurprisingly, the £1,500 cost of this option won’t be particularly appealing to new Prius Plug-in buyers. And that’s before you discover that specifying the solar roof oddly results in the removal of the car’s head-up display, as well as two additional safety features: a blind spot alert and rear cross traffic alert, which will warn you if you’re about to reverse out of a space and into the path of a moving car.

 

Nissan Leaf (2010-2017)

Nissan offered a small solar panel on the previous-generation Nissan Leaf’s roof spoiler, which is fitted behind the roof and over the back window. As it was only a £300 option when new, you’ll find that many used cars are fitted with it.

Unsurprisingly, given its size, the charge it generates is minimal but it can be useful, even though it’s not connected to the car’s main battery pack. Instead it’s used to trickle-charge the Leaf’s 12v battery, which is no different to the battery under the bonnet of a petrol or diesel car.

The 12v battery is essential, as it’s used to power systems such as the interior lights, alarm, radio and clock. It’s also required to charge the Leaf and to turn it on because it activates the main battery pack.

The energy from the solar cell can’t recharge the 12v battery when it’s flat but is enough to maintain its charge, which is gradually lost as it maintains power to parts of the car while it’s switched off.

 

Audi A8 2010-2017

The previous-generation Audi A8 (and the one before that, shown above) came with an optional solar sunroof, with solar cells encased in the glass. It doesn’t let a great deal of light into the car but the energy generated is enough to power a fan when the car is switched off.

When parked in the sun, the fan keeps air moving through the car to prevent temperatures soaring. It doesn’t produce enough electricity to run the air conditioning, though, so the car still warms up in the sunshine.

It was a popular choice in warmer climates but the cost of the optional extra, which came close to £2,000 meant that British buyers found it harder to justify. It’s not something that you’ll easily find on the used market.

The technology was also used on Audi’s A6, and even the Exeo, built by Audi’s sister company, Seat, between 2008 and 2013.

Audi no longer offers the technology on current models but is working on a more sophisticated option, which can be embedded into panoramic sunroofs and eventually generate enough power to charge the batteries of electric cars. It may make an appearance on the company’s forthcoming e-tron electric car.

Read more about:

Latest advice

  1. BuyaCar.co.uk reviews

  2. Cars with 0% finance

  3. Lease vs finance

What our customers say