Solar panels on electric cars always sounded like the most common-sense idea – it’s literally free energy, right? Well, technically yes, but in reality the actual benefits in real-world applications haven’t really been all that groundbreaking.
We don’t have to look too far for an example: Hyundai estimates that the tech only adds about 5 km of range per day on the Ioniq 5, and 3.5 km on the Sonata Hybrid. But despite that, Mercedes-Benz is still convinced that solar panel roof is the answer for EVs, and will begin offering them on their new cars starting from 2024.
The news comes from Mercedes-Benz’s CTO Markus Schäfer, who told the media during a roundtable event after the launch of the Vision EQXX this week.
“Customers probably will have the choice in the future to opt for complete glass roofs uninterrupted, or solar roofs, which are extremely aesthetically attractive, but also the benefit of putting additional energy into the battery,” Schäfer said.
“We work with the German research institute of Fraunhofer … who co-developed with us, solar panels, a very very efficient solar panel roof which we’re putting in our vehicles, and that’s the idea with series vehicles in the future, probably starting 2024 with an increasing number of solar roofs in Mercedes-Benz vehicles.”
Looking at the numbers from the Vision EQXX, it does seem that the German carmaker is actually onto something. Mercedes claims that the solar roof on the concept vehicle is capable of adding up to 25 km of range per day – that’s five times of what Hyundai achieved with the Ioniq 5.
A huge part of that achievement comes from the way Mercedes-Benz handles the electricity from the solar cells. Instead of the drivetrain’s battery, the energy captured from sunlight is fed into a separate lithium iron phosphate (LFP) battery to supply power to the car’s ancillary systems, including the air conditioning, lights, and infotainment system.
By using a separate dedicated electrical architecture, stress is taken off the high-voltage system, thus increasing the range of the car. That being said, though, Mercedes-Benz said that they’re also developing a solar power system that is capable of supplying power directly to the powertrain’s battery too.
Of course, how well all of these translate onto a regular production EV remains to be seen – not every car has a drag coefficient of just 0.17 Cd. Mercedes-Benz seems confident about it, so we’ll just have to wait and see. But one thing we do know is that it’ll at least be quite good-looking, as Schäfer mentions repeatedly…