It could help overcome one of the biggest barriers in the way of the government's desire for us all to be driving electric cars by 2040. That's the infrastructure problem – how do you create enough charging ports to give drivers the confidence to embark upon longer journeys.
Consumers won’t make the switch to electric unless they can be certain that they won’t be stranded somewhere with no way of charging up the battery. Improving the number of charging ports available is one solution, while others have looked at creating roads with inductive charging built in that can actually provide power to a vehicle as it passes over.
But the Sion, a new electric car from Munich-based start-up Sono Motors, takes a much more straightforward approach. It’s the world’s first electric car with built-in solar panels. “The roof, bonnet, rear and the complete bodywork of the car consist of highly efficient mono crystalline silicon cells, which are covered by polycarbonate,” explain the company on their website.
The car can travel up to 30km through solar charging from the 330 photo-voltaic cells embedded in its bodywork, and can also be used as a generator to power other electrical items at events or in emergencies, or even to charge other electric cars. That last function will be facilitated by a smartphone app that will allow Sion owners to sell their excess electricity to others.
Chris Goodall, industry commentator and author of The Switch, told Professional Engineering he was impressed by the design and hoped it succeeded. "It's a complete change in the way cars are marketed and designed," he said.
He stressed that solar power was unlikely to ever be enough to power cars on its own, even if the technology improves. However, he pointed out that the average car travels less than the 30km a day limit that the Sion could theoretically be charged from the sun. "In a hot country in southern Europe, you could leave it in the sun all day and that could give you enough power for the average journey," he said.
The vehicle is innovative in other ways, too. As well as an artificial air filter like the one found in most cars, Sono Motors have integrated moss into the dashboard and central console. “It serves as a natural air filter, which further improves air quality and has positive effects on the humidity inside the car,” they explain.
The company have also pledged to make the car easy to repair, by providing a workshop manual free of charge, and uploading CAD files for each component online so that users can get their own parts printed or milled locally.
The Sion will cost €16,000 (batteries not included) and should go into production in late August, with the first consumers receiving their vehicles in early 2019. The company first came to public attention via a crowdfunding campaign. They have 1200 pre-orders for the Sion, but need 5000 to go ahead with production. A test vehicle will be on tour throughout Europe from August 18th.
Other car manufacturers have attempted to integrate solar power into electric vehicles in the past. The original Toyota Prius had the option of a solar roof, but it gathered a minimal amount of power, and wasn’t connected to the battery pack so could only be used to power the car’s climate control. Roof-mounted solar panels have also been mooted for the new Prius Prime, a hybrid vehicle.
In 2014, Ford unveiled a concept car called the C-Max Solar Energi which had 1.5 square metres of solar panels on the roof and featured a lens canopy positioned above the photo-voltaic cells to focus the sun's rays.
Elon Musk has also previously suggested solar panels would be available on the newly released Tesla Model 3, but later dropped the idea. “I really thought about this,” he said during a speech last week. “I pushed my team. Is there some way we can do it on the car? Technically, if you have some sort of transformer-like thing that will pop out of the trunk like a hardtop convertible that ratchets solar panels over the car, and provided you are in the sun, that would be enough to generate 20 to 30 miles a day of electricity. It’s a difficult way to do it.”