Why vehicle roof-top solar isn't practical. (Unlimited range??)

[alacritousOmega]

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[jjwolf120]

Needs context. Not practical for what?

Most people don't drive more than 70 miles a day. Many rooftop solar installations get far more than 8 hours a day of sunlight. Also, per google average solar panels are currently from 250w to 400w, so you are also using the lowest quality panel.

 

[alacritousOmega]

Needs context. Not practical for what?

Most people don't drive more than 70 miles a day. Many rooftop solar installations get far more than 8 hours a day of sunlight. Also, per google average solar panels are currently from 250w to 400w, so you are also using the lowest quality panel.

Oops, should have clarified 'roof-top'. I meant vehicle rooftop. Home solar is great.

Was doing some rough back-of-the-envelope calculations to see what it would take to get unlimited range for wilderness exploring.

 

[jjwolf120]

Oops, should have clarified 'roof-top'. I meant vehicle rooftop. Home solar is great.

Was doing some rough back-of-the-envelope calculations to see what it would take to get unlimited range for wilderness exploring.

That is what I was thinking. On the Aptera it makes some sense, since the Aptera is 6+ times more efficient than a Rivian R1. To make since on a car, either the efficiency of the car or the panels needs to increase.

 

[Magicbus]

You could tow a flatbed trailer but that might make wilderness exploration awkward.

 

[jjwolf120]

You could tow a flatbed trailer but that might make wilderness exploration awkward.

If you assume that you are unable to get gas, there is probably some distance that carrying extra solar panels instead of fuel trucks would make sense

 

[VSG]

When I see calculations like this it just demonstrates that the OP doesn't know what he/she is talking about. Even as a rough guess this is flawed from the start.

A 4kW fixed solar array on a rooftop will never give you an average of 32kWh of electricity a day. You will likely average between 12kWh and 20kWh. Your average will depend on where you live in the country, how your panels are oriented, whether they are fixed or moving, etc. Because your best days at the peak of summer with long days and high sun will be cancelled out by the worst days in the dark of winter with short days and low sun.

If you are talking about *vehicle* rooftop (or bedtop) then you should FIX YOUR THREAD TITLE AND GRAPHIC.

Your conclusion is correct for *vehicle* mounted solar - as we have discussed many times, in detail, in other threads - when using actual correct numbers.

But your argument is undermined by presenting clearly wrong assumptions about "peak hours" for rooftop solar since those conditions do not ever occur when solar is mounted on a vehicle and because vehicles need to operate all year round, not just at the height of summer. Your number is not even useful as a best-case scenario because you use an unreasonable assumption of surface area and solar cell production.

 

[Dark-Fx]

Your solar car just needs to look like this.

 

[CharonPDX]

Your solar car just needs to look like this.

Nah, just like this:

I should note - the Aptera is *MUCH* bigger than it looks. It's wider than my old F-250! Here it is in 'Augmented reality' in my garage next to my Arcimoto:

Aptera claims an estimate efficiency of 10 mi/kWh (100 Wh/mi.) Its extreme efficiency, combined with being completely coated with solar panels (including on the horizontal part of the dashboard between the instrument cluster and the windshield!) makes it actually feasible to add a reasonable amount of range purely from on-vehicle solar.

Anything without that much horizontal surface area *PLUS* that extreme efficiency just wouldn't be worth it. Sion figured that out. Lightyear figured that out.

That said, in the real world, an Aptera isn't going to be getting "peak solar" all day every day. And I honestly doubt it will have 10 mi/kWh efficiency on highway driving. They claim ~40 miles of range added per day "averaged all year in Southern California getting 10 mi/kWh." I predict that if you don't live somewhere that is "sunny 300 days a year" you'll average closer to 10 miles added per day. (More in the summer, less in the winter.)

 

[COdogman]

Eventually there will be lightweight deployable solar arrays that could add some charge, but I can’t imagine it would be very fast or convenient or affordable. Probably more of an off grid back up solution for overlanding/ camping.

 

[HaveBlue]

https://www.youtube.com/@solarcannonballrun

 

[j.w.s]

Aptera Motors (https://aptera.us/) respectfully disagrees!

With a much smaller and much more efficient EV, vehicle solar can in fact work quite well... at least in my sunny California.

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