flexible solar panels?

[obrien creek farm]

I want to put flexible solar panels on the roof of my bus, but it looks like there about a dozen different brands available, so I am interested in any opinions/experience as to which brand is the best. thanks in advance for any feedback.

[peteg59]

Welcome to the site, ocf.
My only question is: Why do you want/need "flexible" panels?

[o1marc]

Welcome to the site. Instead of saying what brand is best, lets talk why you wouldn't want them. While they are convenient to mount on a curved panel, they really need air circulation around them to keep them cool, they can overheat and diminish longevity and performance. They can't be adjusted towards the sun, so they will be less efficient than a solid panel.
What were your plans?

[john61ct]

Gioco, Solbian, Solara and Aurinco are all **much** better than the cheap mass market kit.

Please don't bother remarking how much more expensive per watt they are.

Obviously. But you did ask for "the best".

[obrien creek farm]

thanks for the welcome. the reason why is I guess is purely visual. I would rather not see them up there. They are clearly marketed for rooftop rv installation, so I assumed heat was not a factor. And after 15 years using solar, I've come to the conclusion that there is no huge advantage in pointing it directly at the sun. I guess there are photons flying around everywhere out there?

[o1marc]

Originally Posted by obrien creek farm

thanks for the welcome. the reason why is I guess is purely visual. I would rather not see them up there. They are clearly marketed for rooftop rv installation, so I assumed heat was not a factor. And after 15 years using solar, I've come to the conclusion that there is no huge advantage in pointing it directly at the sun. I guess there are photons flying around everywhere out there?

Well I guess you've convinced yourself that's what you want against better advise. Good luck with those panels.

[CMORGANSKOOL]

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1


I'm very pleased with the performance of these panels.

[o1marc]

Originally Posted by CMORGANSKOOL

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1


I'm very pleased with the performance of these panels.

Have a pic of them mounted?

[CMORGANSKOOL]

Originally Posted by o1marc

Have a pic of them mounted?

I don't think i do. I'll take one when I work on it Sunday. It's not pretty but it's very functional.

I just used 4 or 6 (can't recall how many holes) self tapping metal screws then caulked a half inch all the way around. Laid the cables where I wanted them and caulked over them to hold them in place. Picked where i wanted the wires to come through and drilled out from the inside. They come into a 30a charge controller I got on amazon for $20. You can see a little of my handy work in this pic.

[john61ct]

Originally Posted by obrien creek farm

thanks for the welcome. the reason why is I guess is purely visual. I would rather not see them up there. They are clearly marketed for rooftop rv installation, so I assumed heat was not a factor. And after 15 years using solar, I've come to the conclusion that there is no huge advantage in pointing it directly at the sun. I guess there are photons flying around everywhere out there?

No, all panels generate huge heat off the underside hurts efficiency, must be dissipated.

And just tilting, not tracking, can double production.

[rffffffff]

I did a test of tilted panels accidentally where one was tilted east about 15 degrees and one west 15 degrees... the difference was almost double on the panel facing the sun as it rose or set.. but the cumulative effect was similar if you’re not going to move the panels as the sun moves. On a skoolie that moves and parks in different places I wouldn’t think tilting will have a net positive effect unless you’re manually doing it to face south and or tracking east and west during the day. The hardware and effort to do so vs the cost of an additional solar panel or two seems not worth it to me personally.

The bigger thing would be to make sure you have enough solar for what you’re doing, or really more than you need, so that the decrease in efficiency is met by additional volume. My only concern with flexible panels would be that you’re getting enough watts per square foot to accomplish that in the real estate that you have.

Good luck!

[john61ct]

If your roof is already as full as it can get and you want still more input, then a tilting rack can **double** production, especially in winter.

Nothing more than tilting towards the equator, tracking more than once a day would get even more.

What such gains are "worth" how much trouble is of course subjective

[Danjo]

I too am interested in flexible panels. the performance degradation associated with heat is a thing.

I contacted Renogy. The rep that I talked to downplayed the problem. There’s graphs that show the optimal operating temperature is 78 F.

Nanoplane installed something like 20 of them on their bus. They installed in direct contact and said is they were to do it again they would have an air gap.

I’ve been trying to work out the air gap for the curved surface. Originally I was thinking about some kind of thermally non-conductive material thats applied to the roof. And then I thought aluminum sheet bent to the curvature of the roof and attached with standoffs.

My latest idea is to lay up fiberglass to make a panel.

I haven’t priced the aluminum/fiberglass options to see which is less expensive.

[rffffffff]

Check out @busgoblin on Instagram. She has 100w panels that are small but not flexible, mounted in close proximity to the roof but along the curve. It seems to me that that concept, buying smaller panels in more quantity and wrapping them around the roof may be the simplest compromise for aesthetics and ease of install. Once again watts/sq ft might be low but if your bus roof is big enough it may not matter.

[nanoplane]

Here are mine, and yes, I'm considering adding a "gap" by adding curved aluminum bars running under the ends and center of each panel. These are 100W panels and I typically get up to about 1800W if the sun is "right"

During the Summer, I'm running totally off solar (not traveling yet), running AC / heating for about 14 hours each day.

[joeblack5]

nanoplane, very nice looking bus.
Johan

[john61ct]

Given their higher cost, much shorter lifespan, and the extra costs involved mounting properly

my reco is just use rigid framed panels instead

[obrien creek farm]

Lots and lots of food for thought here. Thanks to you all. I, too, did an experiment with my home array regarding angle of the dangle one day when it was generating 14.5v, and it seemed to me that no matter which way I pointed it (it tilts and swivels both) the potential remained the same. However, I have learned from experience not to trust anything I say.

[john61ct]

Voltage is not relevant.

Amps into a depleted bank (plus additional high-current loading) is how you measure production.

[nanoplane]

Originally Posted by joeblack5

nanoplane, very nice looking bus.
Johan

Thanks, just wish I had more time to work on it ..

WRT efficiency. my panels are paralleled across the bus in groups of 2 or 3 This allows for different power from each panel as the sun tracks across the sky. I've thought of making them steerable (allowing the outer edge to tip up, but I'm not convinced that I would gain more than 10% overall given this configuration. My tests showed the difference on a single panel between flat and tilted on axis to the sun was about 20%. If I didn't want to obscure any of the panels by tilting, I would only gain this on the far side panel from the Sun. Maybe if I was closer to the equator ... .

I do need to work on the heat issue though, I think it costs me about 20% overall on hot days.