How solar cells are conquering the car
The dream of a self-charging electric car is still a long way off. And strongly dependent on the weather. But solar cells on the outer skin of electric cars are no longer a gimmick for environmentally motivated high earners. Photovoltaics is making progress. And what was just enough to operate parking fans in luxury sedans more than 20 years ago is now being used in series production.
Since the Solar World Challenge at the latest, engineers in the automotive industry have known that the sun can move a lot as a free source of energy. In the race under the sign of the environment, solar racing cars will roll around 3,000 kilometers on solar energy alone. The cars, which were mainly developed by universities, drive through Australia at average speeds of over 100 km/h. With the spread of electromobility, the technology is increasingly finding its way into series production.
No crazy: solar energy for the car
The Fraunhofer Institute for Solar Energy Systems ISE in Freiburg believes in the potential. This is by no means crazy, because in order to implement a CO2-free energy supply, the expansion of photovoltaics must be massively promoted. "Even beyond rooftops and open spaces," says Andreas Bett, the head of the institute. Solar modules will also be increasingly integrated into vehicles in the future. ISE has conducted research showing that cars with solar panels could generate electricity for more than 2,000 kilometers of driving. Depending on the size of the usable area and sunlight, of course.
The Munich-based start-up Sono Motors takes a similar view. The company develops the Sion small car, which is touted as the first self-charging electric car. At prices starting at 25,500 euros, the car is to be launched in 2022 or 2023. Almost invisibly, the manufacturer integrates almost 250 solar cells into the body. In good weather, the Sion will use it to recharge electricity for a range of up to 35 kilometres per day. If the sun is not shining, it can still be charged at the socket. Its battery holds 35 kWh of energy for a range of 255 kilometres according to the WLTP standard.
The sun becomes a range extender
In the Netherlands, another start-up is working on the same idea. However, in a different segment. The company introduced the Lightyear One in 2020. The flat, streamlined coup̩ has five square meters of solar cells on the outer skin. This should be enough for a range of up to 70 kilometers per day. The car is scheduled to go on sale in 2021 Рat prices starting at just under 180,000 euros, but the four-door car has a total range of 725 kilometres.
Again different and yet with a similar approach, the American company Aptera has been tinkering with an electric vehicle for several years. The start-up wants to put a tricycle on the road. Thanks to its extremely low air resistance and the built-in solar panels on three square meters, it should in many cases drive through the life of the car completely without a power outlet. The 180 cells are good for almost 20,000 kilometers per year, more than many drivers drive in the same period. Depending on the drive and equipment, the small car, designed like an airplane without wings, is expected to cost between 25,000 and 50,000 US dollars. Company boss Chris Anthony plans to start production in 2021.
Solar roofs in series production
Beyond start-ups, Toyota has recently moved closer to solar energy. The Prius plug-in hybrid can optionally be equipped with a solar roof that achieves a nominal output of 180 watts. After all, five additional kilometers of electric driving can be charged per day, Toyota promises. With 200 days of sunshine a year, that would be 1,000 kilometers. The electric range of the Prius HEV is 50 kilometers, so the solar panels would save 20 battery charges. However, with a surcharge of almost 3,000 euros, Toyota charges dearly for the roof.
Hyundai also uses the technology in the Sonata, which is only available on the American market. And the upcoming Ioniq 5 electric car, which is scheduled to be launched in early summer 2021, is also likely to have a solar roof on board. There was already one on the Study 45, which gave a preview of the Ioniq 5. As one hears, the production model is also supposed to increase the range.
No chance for shadow parkers
Toyota is already experimenting with larger areas. The solar panels are also mounted on the hood and boot lid of the Prius. However, this still looks a bit coarse on the prototype. But there are already solutions for this as well. At the Fraunhofer Institute, they have developed a solar roof that can be painted in any color. It becomes almost invisible on the car. With 210 watts of power, it should still be able to generate electricity for up to ten kilometers a day for a mid-range vehicle.
The only thing left is the problem with the weather. Because even if solar cells on the car are getting bigger and more powerful. They still need to get sun. So it's not for shadow parkers.