Mercedes-Benz introduced its latest concept, the VISION EQXX, to much fanfare recently. And for good reason.

The electric vehicle is a figurehead for sustainability and efficiency for the automaker, and in that spirit reads like a litany of a new religion: 3D-printed components, vegan leather, recycled materials, and powertrain architecture that results in a range which is, in the present tense, fantastical — 620 miles between charges.

But hyper-efficient battery design is only part of the story. The EQXX also boasts rooftop solar, long a dream of the driver dreaming of independence from the pump…and, more recently, from the charging station. Merc’s press release states that the super-thin panels indirectly contribute about 15 miles to the overall range by reducing drain on the powertrain’s battery. That’s a token supplement, but a start.

We’ve seen the addition of solar on other recent electrics, too, most notably in the Tesla Cybertruck, which features a roof that can be adapted for the purpose. There was also the Lightyear One with its decidedly ambitious solarized-roof plans. And, although a super-efficient commercially available solar panel is not currently produced, they may be on the way through perovskite-based technology.