Audi Turns To Hanergy For Solar Cell Vehicle Roofs

JAN 27 2018 BY MARK KANE 19

Audi has announced a joint development project with Alta Devices, a subsidiary of Chinese solar-cell specialist, Hanergy, on a solar roof.

Audi e-tron quattro concept

The first step will be to integrate the thin-film solar cells into panoramic glass roofs, and then to present the prototype by the end of this year.

It’s expected that the solar cells will eventually cover nearly the entire roof, providing additional electricity for EVs and hybrids – in respect mostly to seat heaters and air conditioning systems, but also to ultimately provide surplus energy to the HV systems for more range.

The efficiency of Alta Devices’ thin-film, flexible solar cells is reported to be over 25%.

Categories: Audi


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19 Comments on "Audi Turns To Hanergy For Solar Cell Vehicle Roofs"

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These solar cells appear to be thin film GaAs cells.

I really hope more EV manufacturers start adopting solar roofs/hoods as an option. With thin film there is very little weight penalty. I’m tired of hearing the argument that its better to have solar on your home. Not everyone own’s their home or is even in a position to be able to do that.

Having an EV you can park outside for extended periods and not worry about it slowly discharging itself would be really nice. As technology advances solar can slowly make up a larger and larger percent of ‘solar miles’ you’d get with an EV.

JD, Most #ElectricFueledVehicles: #EV #PHEV #ZEV #EREV’s do NOT have an issue, long term parked or standing of Traction Battery range loss.

This is known as Vampire Range Loss.

VRL is a term coined for an exhisting condition of older Tesla Automotive cars although Tesle has, over the last couple of year’s put out OA updates to lessen this standing, minor range loss.


Thomas J. Thias
Publisher: Clean Energy Retort™

The reborn Fisker Karma, in stunning design, at least, by US built and based @KarmaAutomotive, a Global #WanxiangGroup Company’s, flagship model, the #Revero, PHEV Sport Luxury Sedan has always had a solar, range extending roof!

Link goes to Karma promotional web site & Twitter post-


Thomas J. Thias
Publisher: Clean Energy Retort™

Me i think it would be a greater benefit to mild hybrids and phevs.

The solar potential is not that great on a small car but on a 40ft trailer however!!

Two square meters at 250W for 10 hours is still 5kw of electricity and nothing to turn your nose up at.

250W each


If these cells are truly 25% efficient, in theory, each Sq. Meter should deliver 250 Watts in ideal Sun angle, for maybe 30 minutes a day at high noon, rising to that in the 1st half day, and dropping from that in the second half a day, for an average efficiency of 10-12%, overall.

Not sure where you get 10 hours of great sun angle at, on a car roof, but that would be nice to get!

The car is going to be parked outside all day at work anyway. If you can generate 5 miles a day (deducting for angle of sun, etc) then that’s going to get you over 1000 miles per year. Obviously it depends on cost but people spend thousands on useless upgrades all the time so why not a solar car roof. Beats spending it on leather interior. I wonder if they can make little solar shades that you can pull down in the car window. Keep the sun off AND make power. Or those windshield foil reflector things people use in the hot south in summer. Can we get a solar version of that with a simple cigarette lighter style power plug?

Because the 250kWh it would take to go those 1,000 miles costs on average what?? $25 or so a year!!!! With the premiums they want for the solar cells on cars it just isn’t worth it.

I am not saying to not make it an option but I can’t see these going mainstream until their cost comes way down or their benefit increases a lot.

A lot of people will buy solar roofs because it is cool not because it makes financial sense.

How much financial sense does an active carbon fiber spoiler make? That only provides significant downforce above 80 mph? How much better is a $5k premium audio system over a standard system? How much better are $10k forged aluminum wheels over cast aluminum wheels?


Just because some people waste money on unnecessary things doesn’t mean we should advocate doing the same.

And rear spoilers don’t crack and peel after a few years, making your car look terrible. I’ve read that tends to happen with the type of thin-film solar cells they put on a car’s roof.

Where I live it would be 150€/year. Then again where I live it most definetly would not be 1000km/year with sunlight from the roof?

Wonder how Audi will market this ‘advance’?
That it looks ROOLY, ROOLY KEWEL?

25% for thin flexible solar is far higher than anything I’ve read about. Who knows though- 50% might become achievable in 10 yrs?

25% is high for a flexible solar cell, but it depends on what people will pay.
If you look at what can be done in research cells. ..

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I think my solar cells at the sailboat was under 20% efficient. Probably closer to 15, and that is only a few years ago.
Then there are loss in the regualtor and converter too.

This would make sense for Hawaii, or any location that has very expensive electricity and is located relatively close to the equator.
However, for most everyplace else, you will lose money on it.

Yet,Audi, like the other car makers, are looking for ANYTHING that will allow them to look like they are outdoing Tesla, while not copying them.

Keep in mind that even if this is 25% cells (very doubtful), it will only be for less than 1 hour with top solar. After that, it drops quickly. That means that the 250 WH that everybody is hoping for, will, on average, be close to 100 WH. So, for a summer day with no clouds, you will get around 1KW, and that assumes no tree, good positioning, not running around, etc.

It certainly would be of benefit to have a small area of solar cells on the roof, to run a ventilation fan to keep the car’s interior from overheating, and to prevent vampire loss.

But as far as adding miles to the range, that’s just not a reasonable or sensible scenario. You’d have to cover the entire top surface of the car with cells, and you’d still at best get only a few miles per day out of it. Far better to spend your money putting those solar cells where they’ll be generating energy every day.