Solar energy has long generated electricity both on building roofs and in huge "solar farms" for utility companies, but only a few cars have had solar panels on their bodies.

Solar roofs aren't a new concept, but Audi and Alta Devices' solution would be the most transparent photovoltaic solar roof implementation yet—literally.

The German luxury brand and Chinese solar-cell specialist have developed a translucent solar cell that can capture energy even from glass roofs.

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The solar cell is completely transparent, which means passengers' views wouldn't be obstructed looking through a panoramic sunroof.

Audi plans to fit the transparent cells in a panoramic glass roof that would power accessories in the car.

Air conditioning, heated seats, and other areas could all benefit from the captured solar energy.

Audi e-tron Sportback concept, 2017 Shanghai auto show

Audi e-tron Sportback concept, 2017 Shanghai auto show

This in turn would also increase the range of electric cars by relieving the onboard battery pack of the need to power aspects of the vehicle that don't actually move it around.

While the innovation is far from ready for full-scale implementation, Audi believes this technology could one day directly charge the battery as well.

“That would be a milestone along the way to achieving sustainable, emission-free mobility,” Audi Board of Management Member for Procurement Dr. Bernd Martens said.

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Audi isn't the first to tinker with the idea of solar panels embedded into cars.

Ford showed a C-Max concept with solar panels equipped with the roof, though they weren't transparent like Audi's.

The 2010 Toyota Prius also offered an optional solar panel at the back of the roof, which provided enough power to cool the cabin when the engine was shut off.

Audi e-tron Sportback concept, 2017 Shanghai auto show

Audi e-tron Sportback concept, 2017 Shanghai auto show

One one notable aspect of the 2012 Fisker Karma range-extended electric luxury sedan (now relaunched as the 2017 Karma Revero) was its solar roof.

For Audi, the technology is part of a continued move away from diesel following parent automaker Volkswagen Group's diesel scandal.

While most of Volkswagen's scrutiny was focused on the VW brand itself in North America, Audi has come under fire in Europe for its diesel engines as well.

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The luxury marque has also been accused of colluding with BMW and Mercedes-Benz to rig diesel emissions on the continent for years.

Audi plans a slew of electric cars in the future, which will feature the "e-tron" badge.

As for the solar-panel glass roofs, Audi didn't predict the timing of production but said it plans to build a prototype with Alta Devices by the end of this year.

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