Lensun panels (post install status)

[Nelo]

Hello everyone and thank you all who participate in this forum, it has been a wealth of knowledge and humor.
I have three 80 watt Lensun flexible panels that I will be installing on our 2023 E19.
Some of you have already done this installation and I’m curious as to the status after 3-4 years post installation?
I would really like to use the direct method of attaching the panels to the roof fiberglass/gelcoat.
I like the idea of using the heat conductive tape between the panel and the roof with EternaBound tape on the perimeter sealing the sides. I also hope the heat conductive tape will provide good enough adhesion and help prevent lifting caused by the low pressure over the panel when the trailer is moving (Bernoulli principle) but since the air under the panel will be static I’m not sure this is even a problem?
I understand that the roof is not going to provide a great heat sink, but it should do something to dissipate/transfer the heat and not effect the interior insulation. We will be doing desert trips and temps can get pretty high!
I also think the corrugated plastic between the roof and panel with venting capabilities has its merits, but it too can have its own issues.
I am also installing a Houghton 9500 AC with an RVsoftstart installed, and building three LifePo4 battery banks using Eve cells for over 9.5kwh of power, and a Renogy 2000 inverter. It should be coool, and intended for at least an overnight off grid with AC. It’s a go big or go home approach!
Thanks for all your help
Nelo

 

[Ron in BC]

I installed a 100W flexible panel using Eternabond. It was there for 4+ years until I removed it this year to install a bifacial 210W panel in its place.

It's now is serving as a portable panel for a friend's camper.

There had been many negative reports about flexible panels causing damage to the gel coat. There was zero damage to my gelcoat and no visible difference between where it was and the surrounding area. We have spent some hot times in Arizona and Baja.

I'm not sure that I'd worry about the Bernoulli effect. It works best when there's a smooth flow of air over a surface. By the time air reaches the panel, after hitting hatches and vents etc., it's anything but a smooth flow of air.

Ron

 

[ColoradoSwany]

Four years and mine still going strong. Here’s my thread on installation:

https://www.escapeforum.org/forums/f8/14-solar-installation-questions-17711.html

 

[HABBERDABBER]

"I also think the corrugated plastic between the roof and panel with venting capabilities has its merits, but it too can have its own issues." by O.P.

What are the issues with the corrugated plastic panel? It seems like it would provide a thermal insulating break. It could complicate attachment of the panels some.

 

[Nelo]

My main concern was the possibility of damaging the fiberglass, or cause the interior insulation to separate, or damage the panels!
Thank you Ron for sharing your experience with the panels, also correctly stating
Bernoulli effect and not principle.

As far as the question about corrugated plastic between the panels and the roof.
I really like the idea of having some kind of heat escape and think every little bit will be good for the roof and the panels. However, I was thinking the possibility of accumulating debris and then collecting water could be a problem when a freeze occurs. The panels will contract and the water freezing will expand, maybe a problem for the panels, maybe not, and I could be over thinking it! But we do visit friends in northern Nevada during the holidays and it does freeze overnight. That’s all, just throwing out possibilities.
Thanks
Nelo

 

[HABBERDABBER]

What could go wrong?

Me thinks you are over thinking it.

If some water droplets were inside a corrugation and froze, so what? Debris? Who would see it, and what negative effect would it produce?
One could tape off the open ends with aluminum or other tapes made specifically for that purpose.

A thermal & insulating break can aid panel efficiency and panel longevity. It would act to insulate the fiberglass body and internal insulation, although both are mostly impervious to the temperatures experienced.

Good luck,

 

[Jim Bennett]

I installed four of them, 80W each, and now 7 years later they are doing great and are still in great condition. They are taped with Eternabond on the edges directly to the fibreglass and I have had nary an issue. My brother did similar using VHB tape and that worked well too. I have gone up in the bright sun and felt the panel and the heat there is not much higher than on the bare glass beside it.

We were in a bad hail storm where there was near golf ball sized hail. While all the plastic pieces on the roof suffered damage and the awning cover was dented up with a couple spiderweb type holes in the fabric, the trailer itself and the Lensun panels took the punishment very well, no sign of damage to either.

On my 5.0TA you can't even see the panels short of being a ways to the rear and you can make out a couple of them due to the sloped roof. I like that.

 

[Ron in BC]

They are taped with Eternabond on the edges directly to the fibreglass and I have had nary an issue. My brother did similar using VHB tape and that worked well too.

When I first heard about Eternabond and looked it up I thought, "Wow, pretty pricy for glorified duct tape." After 4 years exposure to the elements I think that it's great.

When I went to remove the panel I had to insert a knife under the panel and cut it free. Different YouTube videos show have to remove the now unwanted tape. Most of them aren't very accurate. A sharp chisel and acetone are your friend.

As the photo shows, 4 years of being covered by the flexible panel hasn't done anything to the f.g.

Ron

 

[Mark B1]

Mine are installed with 3M VHB tape and have been on for over 4 years. I did focus on good prep work for good adhesion which IMHO is the most important part. I put did one row of tape around the whole perimeter of each panel with no gaps seal the panel to keep moisture out. No other chalking or sealing was sone. I fielded a few strips on the middle of each panel to keep a consistent gap with the fiberglass trailer and the panel as around the edges. We have seen the typical Alberta weather (heat, rain, hail, and multiple deep freeze thaw cycles) as well as a few longer road trips driving through rain and snow. They panels are still secure with no gaps or signs of failure. I think VHB tape should be easier to cut to remove the panels and the residue comes off with a 3M rotary tool (drill mounted eraser).

 

[Nelo]

Solar panel test
I did a quick test to see what the temperatures were on and under the Lensun panel.
I have a scrap piece of my 2023 Escape 19 hull with all the insulation and vinyl attached and used that as part of the test area A.

Test set up
A) taped the 5”x8” hull scrap to the bottom of the panel.
taped a 5”x8” 1/4” piece of cardboard to the bottom of the panel.
C) open air
I used a handheld infrared temperature gauge for readings in F.
I left the test set up in direct sun for three hours and then measured temps.
Ambient temperature was 84 degrees, no clouds and test ended at 1:30 PM in El Segundo, CA.

Test results
Surface temp exposed to sun
A) 150
148
C) 128
Underside temps.
A) measured at the vinyl ( like it would be on inside of the trailer) 109 degrees.
measured bottom of cardboard 127 degrees.
C) 132 degrees.

For the heck of it I also measured the open circuit voltage. At the very beginning of the test it was measuring 22.8VDC and at the end of the test it was 21.5VDC
This is just a quick test and only somewhat accurate but it gives me an idea of what is happening under the Lensun panel. I am going to get some corrugated twin wall plastic and do this test again. I think the twin wall may have some interesting results.

Again this was a first shoot at making a quick test and is no where conclusive but it’s interesting to me, especially since I will have three panels on my trailer. It would also be interesting if some of you with flexible panels can take measurements inside your trailer directly under the panel and then again in an area with no panel over it.
Thanks
Nelo

 

[HABBERDABBER]

Bravo!

That's the way to answer your queries. Explore, test.

The big box home centers often have double walled polycarbonate, clear, about 1/4" total thickness, at reasonable prices. I bought a 4'X8' sheet a little while ago for some mini-greenhouse construction. It's pricey, but they also sold a special tape to seal off the open butt ends. No need for my application, and you may want to leave them open for what little ventilation cooling effect there is.


A fully stand-off, air gap "insulated" position seems best, but not possible in your application. A rigid, framed panel above the surface is good too, but that creates a bit of an aerodynamic wing.
So a flexible panel with a corrugated backing appears, in my mind, to be a reasonable solution.

You could mount your flexible panel on a larger sized corrugated sheet to keep the corrugation openings open for air flow.

 

[Ron in BC]

You could mount your flexible panel on a larger sized corrugated sheet to keep the corrugation openings open for air flow.

How would the corrugated sheet be attached if the ends are to remain open?

Ron

 

[Nelo]

I’m thinking I would use EternaBound accross the leading edge and the trailing edge. Then some 3-4” strips of the twin wall around the perimeter. The twin wall would be affixed with 3m VHB. I would cut the Twinwall for the sides at a 30 degree angle or something like that angled to the rear, that way it won’t become a whistle as you go down the road and maybe other benefits, again may probably not be an issue but I like the idea. Also, I would put strips of the twin wall spaced ? in the center.
The whole idea is to keep heat from conducting to the inside of the trailer, and provide a way for the heat to vent out. I’m getting my ideas from all of you and I sure appreciate you all jumping in on this, I know it’s been discussed at great lengths already. Now if I could just find a place to put the automatic dishwasher.
Thanks
Nelso

 

[HABBERDABBER]

No problem!

. Now if I could just find a place to put the automatic dishwasher.
Thanks
Nelso

Oh, that's easy.

Ditch the bikes and get a rear hitch platform carrier and fasten that dishwasher securely to it.
The bumps and turns may aid in speed and efficiency of cleaning that dish ware whilst running done the road.

You did order & get the outside dishwasher hookups, right?

 

[HABBERDABBER]

This?

How would the corrugated sheet be attached if the ends are to remain open?

Ron

Attach the larger piece of plastic corrugated sheet with VHB all around and add Eternabond tape to two sides, leaving the corrugations open and facing parallel to the trailers long axis.
Then bond the flexible panel to the corrugated sheet with VHB tape and more Eternabond around the perimeter. As long as the corrugated sheet is cut large enough, there's room for another perimeter of the Eternabond around the solar panel.

 

[Nelo]

Thank you all for your input. I will perform another test and post updates

 

[HABBERDABBER]

Clarification

The sheet material I have been referring to as "corrugated" is actually called twin wall polycarbonate material. No wavy corrugations with what I have suggested.

 

[Nelo]

Thanks Habberdabber that’s what I will try