New idea for rear window photovoltaics

Mo beddah! Or use both?

@kiteboarder Inside louvers might still be a PITA to clean dust and dirt of off. Depending on widow tint, it might reduce the solar efficiency substantially. Yes it wouldn't impact aerodynamics, but possible reduction in the light reaching the cells and possibly a higher temperature in the interior of the car might make having the interior solar panel not worth it.

Yeah, but it's pointless to have a back window if you're going to cover it up with solar cells anyway. Jury is out on aero.

@togetherinparis No jury needed, since there's zero aero loss with louvers inside.

Louvers INSIDE, as mentioned above.

the angle would have to be according to the same optimum solar angle regardless of different ambient non solar heat , which differs at times, so this maybe used to minimize average energy usage of servo motors in higher heat situations, but not a stand alone system.

such system would probably only be helpful for parking, not on road where servo motors would have to be moving too often, probably something more energy than earned, or not adding energy in total despite needing lubricant. such would also allow for slower smaller, more efficient servo motor operation

its much more likley that not transparent rear with cameras are more efficient than all this as i mentioned in this thread, especially if using lower graphics but no electronics optic fiber system

forgot to mention the blocked visibility of rear area with camera is better than transparent material assuming transparent material is less efficient in crash protection per mass efficiency.

https://www.aptera.us/forum/aptera-design-discussion/color-neutral-semitransparent-organic-photovoltaic-for-power-window-application

^keep account of transparent solar panels in windows,windshield

https://www.aptera.us/forum/main/comment/608627813cb5850016a63158

^windshield wiper related benefit of camera rather than rear window

Great idea! Even tire pressure might be used to twitch the car into better solar cell performance, eh?

At what latitude? The optimum pitch for solar is roughly equal to the latitude. I think I'd have to park on a pretty good hill get them to 41 degrees. Think there going to be enough suspension travel to do that? Even for Miami FL it's 25 degrees. Now if I lived a lot closer to the equator....

A flat configuration (such as with the proposed louvers) could actually have more access to more sunlight overall than the current sloped rear surface. For anytime that the sun is coming from directly above to anywhere forward, the rear-facing slope is a detriment (since it is facing more away from the sun than flat) whereas the flat surface would at least pick up some more of that light from the front. However, if the sun is coming from behind, then the current rear slope would be better than flat / louvers. Also, at specific angles with sun from the front, higher/forward louvers could actually shade forward edges of lower/rear/adjacent louvers and panels a bit. So, it "all depends" and may all essentially wash out in the end as the car moves around 360 degrees in 3D space. Flat / facing directly up louvers could potentially cover some more cases from more angles than the current rear-sloped configuration, though, depending upon how the louvers would be positioned and spaced.

Placing solar panels on louvers may create other issues regarding integration and wiring with the louver materials and (as others mentioned) aerodynamics. And they are more effort to clean around/between/under.

I ordered the roof/nose package without the rear solar panels since I personally prefer the openness of being able to directly see the world out the back. Although the lateral field of view is not good, the forward and aft view is good and I personally would like to maintain that (beyond just indirect camera viewing). If solar panel louvers ever became a viable option, I would add them if I could also keep most of that rear visibility at the same time.

Thank you for sharing the interesting idea, @togetherinparis . I assume it is unlikely to be done at this late point in their development cycle, at least for the initial production runs / model, though it is still an interesting concept for them to perhaps consider for the future.

Allowing the louvers to move some would allow manual tracking of the sun, perhaps, but it's probably not really worth it to allow them to move across the driver's rearward vision. Yes, mid-day sun is best and should never be wasted, hence the horizontal placement on the louvers. If all the solar panels on the rear hatch could be horizontal, the daily solar-generated range would likely increase by a couple miles/day. It would also increase efficiency of production as all the cars would be treated the same. The solar on the back window vehicles would me made like all the rest and the solar panels could just be carried as one piece and put on the outside (or inside) of the back window. The solar panels could even be made up at least partially as louvers themselves. The beautiful triangular patterning could be kept uniquely in a styled louver set up, huh? It's going to look great either way though.

I am a genius. Star Wars was my idea actually. I'm also the source for Elon's higher voltage, one-circuit/bus, and signal function wiring design that Tesla hasn't been able to figure out how to do just yet. They could also put the louvers inside the window and keep the stock aerodynamics. Oh, and I modeled for the Doc character in BTTF, the two Wells Fargo letters are in my handwriting because I wrote them, and my name's on Elliot's ET frog lab doodles, top left, original version only. Of course, that's probably more information than you wanted. I guess I'm just flattered.

You're going to do this, obviously, and I'm glad to help, no royalties demanded either. I'm also invested by $2000.00!

You can hire me America! I've found the cause and cure for 50 killer diseases, too. Aptera should modify their contract to get their solar cell supplier to build the louvers (inside or out) and install the solar panels there instead of blocking the rear window completely as now contemplated. This is just far too great and easy an improvement to ignore for three years.

Solar panels should be optimized for the parking lot rather than travel, so the flatter the better. It's fairly sure that flat parking lots would be the prime solar charging locations, no? Louvers for car back windows are simple to make and a style and flare combined with intelligent wiring, the practical side, is the part for the real meaningful collaboration. Ditching the rear-view mirror camera for a real stock rear-view mirror will lower costs enough to pay for fabricating the louvers, designing them, and wiring them up probably the same way they're wired up on the car. Photos of the "improved" Aptera would also make the blogs.