Automotive

Panasonic develops solar car roof for Prius

Toyota Prius with the solar roof option developed by Panasonic
Toyota Prius with the solar roof option developed by Panasonic
View 3 Images
The solar roof is capable of generating 180 W
1/3
The solar roof is capable of generating 180 W
Toyota Prius with the solar roof option developed by Panasonic
2/3
Toyota Prius with the solar roof option developed by Panasonic
The solar cells are laminated in a resin set atop the roof's curved glass
3/3
The solar cells are laminated in a resin set atop the roof's curved glass

Solar car roofs have generally been the reserve of concepts, experiments and niche carmakers. Toyota was the first major automaker to offer the option on its Prius hybrid plug-in model in 2012 and now Panasonic has developed a solar photovoltaic car roof for the latest Prius PHEV, upping the wattage from 50 W to 180 W.

Called the HIT Photovoltaic Module for Automobile, the 180-W-generating roof is the first designed with the ability to recharge the lithium-ion powertrain battery, along with the standard 12-V lead-acid battery. Panasonic's solar roofs have also been designed with a resistance to hot environments, which normally lead to a decline in output as the temperatures rise.

The previous Prius solar roof only generated nominal electricity: enough to power the ventilation fans when in park, and for use as an auxiliary charging source for the 12-V battery. And while 180 W still doesn't provide much oomph, Toyota says it would increase the car's efficiency by up to 10 percent, adding up to 2.2 miles (3.5 km) of range per day, in ideal conditions.

The solar cells are laminated in a resin set atop the roof's curved glass, a match in design with the Prius's regular hard-top. Unfortunately, this reinforced glass sheeting hasn't passed rollover crash tests in the U.S., so the solar roof option is currently only available on the Prius in Japan and Europe. However, the company is continuing to work on a solution to offer it on US models.

Buyers will have to judge if the add-on is worth it. While the small daily extension in range may add up over the lifetime of the vehicle, the price of the solar roof option runs £1,500 (US$1,840) for consumers in the UK. Installing it also requires the removal of the head up display, blind spot monitor and rear cross traffic alert.

Panasonic has become a major player in the battery market, partnering with Tesla on the company's Gigafactory, which will soon begin churning out record numbers of lithium-ion car batteries. Tesla CEO Elon Musk has stated the coming Tesla Model 3 will probably have a solar roof option as well. And now with Panasonic introducing its new solar roof, it's possible that the two companies may collaborate on the solar roof option.

Source: Panasonic

8 comments
Terence Hawkes
Hmm, the ouput of the panel is 180 W. After 10 hours exposure to full sun, the collector has managed 1.8 kwh. That is a tiny weeny amount compared to what is needed to charge the battery, This is a neat idea, but not practical.
JimFox
Another 'small step for man....' waiting for 'a giant leap for mankind'. That 'giant leap' will be raising solar PV efficiency above 80%
Buellrider
I just bought a Prius Prime Advanced and this solar rooftop idea had me until it mentioned giving up the HUD ( Heads Up Display ). That'll never happen. Since we bought it, the gas engine has only come on once. Get that solar rooftop to actually top off the battery in a reasonable time and you'll have a convert but not until then. Plug-in Prius is a winner.
DavidSchaller
"Toyota was the first major automaker to offer the option on its Prius hybrid plug-in model in 2012" isn't really true, unless you don't consider Audi a major automaker. Audi had a solar powered roof as an option on the 2003 RS6.
Paul Anthony
Why so at the roof, why not all surfaces? There has got to be a more economical panel, that price is outrageous!
Douglas Bennett Rogers
A white roof will probably save more money than the PV's, which are necessarily black.
Daishi
A 180W panel in a place like AZ with 6+ sun hours per day would be about 1kWh/day or about 12 cents per electricity per day. At $1,840 it would take 42 years to pay it off and that's assuming you live in a place with a decent amount of sunlight and not somewhere like Seattle with like 3 sun hours a day. I wouldn't put one of these on my car but I'm sure some people will. Covering the whole car would make more energy but produce an even lower return because it would include areas that are out of sunlight most of the day or at really bad angles. This is useful for saying "look I have a solar panel" but these are not going to be practical on cars for at least the next 5 years but I suppose someone has to fund the early versions.
Jason Catterall
What a colossal waste of money.
Thanks for reading our articles. Please consider subscribing to New Atlas Plus.
By doing so you will be supporting independent journalism, plus you will get the benefits of a faster, ad-free experience.