Toyota Testing New Solar Panels to Increase EV Range

Placing solar panels on electric cars makes plenty of sense. Lithium-ion battery packs are close to having a similar range to gasoline-powered cars, but they're still some distance off. Having high-tech solar panels that feed clean energy back into the vehicle would improve range for no additional cost. It seems like a great idea in theory, but in practice, it's a tricky thing to perfect.

Toyota's Been Perfecting Solar Tech

Back in 2016, Toyota had solar cells on the Prius PHV that was only offered in Japan. But now, the automaker is back with its latest batch of solar cells that are from a partnership with Sharp and Japanese national research organization NEDO. Once again, the solar panel cells will be placed on a Prius.

Working with NEDO and Sharp, Toyota set out to study how solar cells could affect the cruising range and fuel efficiency of a battery-powered car. The technology has been in the works for three years and began as part of the PV-powered Vehicle Strategy Committee. The goal of the committee is to achieve an output of 1 kW in vehicles through a solar battery module.

The new solar panels have been greatly improved from the ones found on the 2016 Prius. They measure in at 0.03 mm thick and, thanks to their more compact size, have been placed throughout the majority of the Prius' body, including the curvier parts of the body. Places like the rear trunk, hood, and vehicle roof have all been outfitted with solar panels. Together, they account for 860 watts of power output. That's a major improvement over the solar panels on the Prius from 2016 that only had a power output of 180 watts.

While the number of solar panels has a lot to do with the increase of total output, their conversion efficiency has increased, as well. The old solar panels had a conversion efficiency of just 22.5 percent. That figure has gone up in the new panels to roughly 34 percent.  

Charging While Driving

Another major enhancement was made when it comes to charging. In the old Prius PHV, the solar panels would only get energy when the vehicle was parked. While helpful, it only accounted for less than 4 extra miles of total range, instead primarily assisting with running auxiliary items, like the navigation system, when the vehicle was standing however. The new solar panels have an innovative system that allows them to charge the vehicle while it's being driven. And now, range is up by roughly 27.6 miles.

Public road trials of a Prius with the new solar panels will commence this month. It's likely that, once again, the technology will be limited to Japan.

Toyota isn't the only company looking into solar cells to help power EVs. Dutch company Lightyear recently came out with a vehicle that has an extensive amount of solar panels for an extra 60 miles of range.