New FWC Solar Panels

[BrianG]

FWC has switched to a new brand of solar panels. I was just at the factory getting my new truck fitted and noticed how different they looked. Apparently they work when partially covered and have excellent output and are lighter in weight.

Anyone know the brand?

 

[Stan@FourWheel]

Overland Solar

 

[Vic Harder]

$370!
https://overlandsolar.com/products/145-watt-semi-flexible-sunpower-gen-3-panel

 

[scappoosebrad]

Wow, these look much lighter than our 160w panel factory installed on our 2016 Fleet... how does this look installed? love to see a photo and weight comparison...our panel is about 3" think off our roof and I believe is affected by the wind and occasionally causes "roof popping" ... anyway, it appears the profile is probably much thinner on roof...plus more sensitive to "partial or shaded light"...

Again, would love to see more details... thanks Vic for the product reference...

 

[XJINTX]

I realize the FWC crew are the experts but I have friends that have had issues with flexible. One even lost his entire panel as he did not secure properly I guess... he swears he did. Also think, here in TX anyway, that some have had heat related issues? I know there is probably a weight savings but one 160W panel is not all that heavy considering the gear I take Guess we will wait and see.

 

[pvstoy]

http://www.wanderthewest.com/forum/topic/15718-what-brand-is-the-160-watt-solar-panel-fwc-provides/page-5#entry195136

Information in the above post. They weight 7 pounds just the panel.

 

[bwag]

That is how mine is mounted, camper installed on 05/04. Took it out to the Coast this weekend, was sunny the first day, second day was morning fog/overcast all afternoon, panel was still charging my batteries and my two way refer kept the haagen dazs frozen!





http://www.wanderthewest.com/forum/topic/15718-what-brand-is-the-160-watt-solar-panel-fwc-provides/page-5#entry195136

Information in the above post. They weight 7 pounds just the panel.

 

[pghjon]

I realize the FWC crew are the experts but I have friends that have had issues with flexible. One even lost his entire panel as he did not secure properly I guess... he swears he did. Also think, here in TX anyway, that some have had heat related issues? I know there is probably a weight savings but one 160W panel is not all that heavy considering the gear I take Guess we will wait and see.

Mainly heat related issues with flexible panels occur when the panel is applied directly to a surface, not allowing it to breathe on the underside.
These panels are not applied directly to the roof.
They are also installed with some supports that make them more rigid than just a panel flapping in the wind.
The main benefit, besides weight, is the significant increase in output when the panel is partially shaded over the older Zamp panels.

 

[rando]

This doesn't make much sense to me. The panels heat up because they are black and in the sun (although only 80% as much as similar black thing would heat up as 20% of the incoming energy is being converted to electricity ). On the other hand, the roof is a huge sheet of aluminium that is nice and cool, because it is white and doesn't absorb much solar radiation. My thinking is to heat sink these hot panels to this large very thermally conductive radiator by mounting them right on the roof. This is the same approach taken for most thermal management problem, you have an object that overheats (say a CPU) you strap it to a large piece of aluminium to conduct the heat away and radiate it to the atmosphere (ie a heat sink). The panels won't radiate much heat out the back side, as the roof is white and reflects it right back, but you can use the high thermal conductivity of the aluminium to your benefit.

Now obviously this doesn't work if your solar panels are mounted to a super hot asphalt shingle roof, which is probably where the advice to leave an air space comes from.

Mainly heat related issues with flexible panels occur when the panel is applied directly to a surface, not allowing it to breathe on the underside.
These panels are not applied directly to the roof.
They are also installed with some supports that make them more rigid than just a panel flapping in the wind.
The main benefit, besides weight, is the significant increase in output when the panel is partially shaded over the older Zamp panels.

 

[PaulT]

+1 rando.
I had to stop thinking about this because it didn't make sense to me either. White aluminum skin should be net cooler than very dark solar cells sitting on it.

I suspect the real reason for problems may involve work hardening due to gazillions of repetive small excursions as the roof vibrates from the road and wind. Think paper clip bent back and forth a bunch. Each solar cell in a flexible solar panel is a thin sort of metal plane. I don't know the material characteristics of that sandwich but the encapsulating materials are relatively soft and compliant as compared to those on a rigid panel.

Just a thought.
Paul

 

[ckent323]

Rando, et al,

I wonder about the failure mechanism of the panels. Perhaps the adhesive used to attach some of the failed panels directly to the roof is not thermally conductive. Or maybe the panel material had poor thermal conductivity. I wonder if that material is the same on the new units now. I wonder what they changed?

perhaps a chemical interaction of panel material and adhesive? It seems to me that there are there are a number of possible failure paths.

It seems to me that bonding the panels to the roof would stiffen the roof up a bit and that makes me question a vibration related failure related to bending. I doubt the deflections are very large. That written if there is data on work hardening of the panel materials that would be interesting to see.

Without data all we can do is speculate, I would very much like to see the panel failure analysis data.

 

[Vic Harder]

Well, it occurs to me that the heat sink idea won't work, as between the solar cells and the roof is a nice layer of insulating plastic that cells are encapsulated in.

 

[rando]

Agreed that the plastic is not a great thermal conductor, but it is much better than air. Some of the flexible panels use an aluminium backing sheet, but that seems to be rare.

My point is that it is not clear to me that air space behind the panels will make any thermal difference and promote/reduce failures.

 

[pghjon]

all I know is an air gap is required/recommended by solar installers and resellers like overland solar. They dissipate heat off the back side. If the panel heats up, efficiency is reduced and it fails faster....google tells me so (and overland solar, the reseller of these panels told me).

online for instance -
http://www.solartechnology.co.uk/support-centre/fitting-your-solar-panel

"Permanent

When permanent fitting is required it is important to leave a minimum 10mm air gap underneath the panel to allow for heat dissipation. Solar Fitting Kits ensure the correct air gap is achieved. Fitting Kits are simple to use and full instructions are provided."

will is pretty well versed on solar as well -