Audi electric cars will come with solar roofs | Hacker News Reader

Audi electric cars will come with solar roofs

foxnews.com

17 pointsyawz14 comments

Regular cars need this.

Leave a car for months, and you'll get back to a dead battery. Keyless entry won't work. You can't roll down the windows. Settings may be forgotten. There is no way to start the engine.

Leave a car out in the Sun in a place like Arizona, and stuff melts. If you get in the car, the seatbelts cause burns that blister. Having the car run a fan would be nice, and the more you need it the more power there is available to do so.

Probably about as "feel good" as the panel on the spoiler of our Nissan Leaf: looks cool, doesn't do much. Keep in mind that a Leaf does about four miles per 1000Wh. That Audi can't have more than 200W worth of panels.

Also, garages.

Negligible performance improvement at great added cost and increased weight. It's a sales gimmick.

They might be better off installing a lighter roof and reduce overall weight to increase range.

Yep. The Fisker Karma had this feature too.

The cynic in me wonders how much government subsidies for alternative energy vehicles prop up expensive, nearly pointless features like this.

Park it in the sun, leave the air con on.

I've done the math: even if I covered the top of our VW Westfalia camper van with solar panels (400-500W max), the panels couldn't begin to generate enough power to run even the most efficient A/C unit.

Better to just park in the shade with the windows cracked.

The A/C units are rated in tens of thousands of BTU per hour for a car. 10k BTU/hr is 2.9 kilowatts.

Fans might work, but not the A/C.

Though there's telemetry for it, I've never paid attention to how much our Nissan Leaf's A/C pulls. What I do know is that it doesn't kill the range nearly as much as the heater, so let's say it pulls half what the heater does. Heater pulls, give or take, 3000W (that telemetry, I've paid attention to). Figure out how to squeeze 15 100W panels on the roof and you're golden.

im pretty sure the maths doesnt work out in favor of this. it'd be more efficient to simply insulate the roof better, than to try to capture solar power.. but maybe I'm wrong.

It's not better to improve the roof's insulation because 90% of the heat comes in through the windows.

Electric roll-up blinds...

Well, it might be enough power to run the fan.

Exactly - my car has the sensors to do this already, it knows the inside and outside temp, I would like it to crack the windows when it's hotter inside, and run the blower on low. It could even use the rain sensor on the windshield to close them if necessary.

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