Flexible Solar on polycarbonate sheet

[Alvis]

I picked up a 120W flexible panel, but did not want to stick it to the roof without some sort of air gap. I decided to VHB the panel to twin wall polycarbonate sheet that I reinforced a bit with aluminum C channel on the sides. So far so good, I went to West Texas to visit my mother and hit Palo Duro Canyon, Caprock Canyon, and Coppers Break on the return trip. It did not blow off, so I'm calling it a success. The whole assembly weighs approx. 8.5 pounds, so I like the low profile and low weight aspects.


C channel aluminum on edges

Panel VHB'd to polycarbonate sheet, with threaded bolt through entire assembly, included L brackets on roof.

Panel fending off flying lawnmower.

All connected to Victron energy 75/15 MPPT controller with Victron energy BMV-700 battery monitor. I have the bluetooth dongle and phone app so it is really easy to pull up the app and check your status. So far seems to be working well.

greetings from Texas,
Alvis

 

[DavidGraves]

Hi Alvis

Off hand, where did you get your panel ?

Do you have dimensions and base weight for it ?

Cost ?

Many thanks

David Graves

 

[todgru]

Hi Alvis. Great idea! Ive been looking into something similar for my Fleet.

How well will the polycarbonate hold up to the sun?

Thanks

Todd

 

[Gussie]

Idiot question, but what is VHB?

 

[Alvis]

Some quick answers to questions:

VHB - trademark for very high strength double sided tape made by 3M. google 3m VHB and you will find many flavors of this product.

120W panel purchased from solarblvd.com - see https://www.solarblvd.com/products/solar-cynergy-flexible-bendable-120-watt-12-volt-solar-panel/ This shows specs. They list weight at 10 lbs, but I believe that to be bundled up shipping weight. I did a quick stand on the scales for the polycarbonate sheet, panel, with aluminum sides that it was less than 9 pounds.

Twin wall polycarbonate sheet specs - http://www.palramamericas.com/Products/Flat-Sheets/SUNLITE-Family/SUNLITE/ It is designed for exterior applications ( green houses, etc.) so should hold up. I was concerned about the temperature specs, but I found some numbers that assuaged my fears. The "channels" run the length of the panel, so air flow through it should help keep the heat down. I bought a sheet of this stuff at HomeDepot. Have enough of a sheet leftover that I might use it to back a smaller panel for portable use.

L brackets - I used a combination of VHB tape and existing roof screw hole (new bigger screw) to provide my anchor points on the roof - then sealed the brackets with Dow Corning 999-a sealant.

 

[DavidGraves]

Many thanks

David Graves

 

[EnviroProf]

Alvis, are you still happy with your setup? Anything you would do differently?

I see that Solar Blvd. is currently out of the 120 Watt flexible panels, but I talked to someone there today who told me they hope to get their next shipment sometime in Sept.

 

[todgru]

EnviroProf,

I installed a nearly identical setup as Alvis - same 120W panel from Solar Blvd, polycarbonate sheet from Home Depot and 3M VHB tape from Amazon. I mounted with a home brew aluminum frame to my yakima rack tracks.

I've had this out in the forest through trees, central Oregon desert, on washboard roads that made my kidneys hurt, freeways at 75 MPH, and outside temperatures as high as 108F. I'm taking the rig out to the Alvord for 10 days next month and I have no worries.

It is working perfectly! No issues. Everything is really solid. The total weight added to my Fleet roof is only 8 to 10 pounds. Very light.

I recommend this setup!

 

[DavidGraves]

Todd

Great to hear the flex panel is working out....that is so much better than adding extra weight up top.

Solar Blvd. seems to be out of stock for the foreseeable future on the flex panels.

Know of any other source ?

Many thanks

David Graves

 

[todgru]

Only other place I've looked for the flexible panels is Amazon. They carry them, but more expensive. Not sure the brands are the same.

 

[todgru]

Here is a pic of my version of the flexible panel mounting:

 

[Alvis]

Alvis, are you still happy with your setup? Anything you would do differently?

I see that Solar Blvd. is currently out of the 120 Watt flexible panels, but I talked to someone there today who told me they hope to get their next shipment sometime in Sept.

EnviroProf, I have been very pleased with this setup (energy harvested, weight, low profile). With the way I secured the ends (threaded rod), I could probably mod it to tilt up on one end, but have not wanted to mess with that yet.

 

[Squatch]

This is great to hear. I was looking for panels about the same time that folks started having problems with the Renology flex panels.

So I ended up buying a conventional Solar Cynergy glass 160 watt panel. It works great but I'd love to get rid of some of that weight.

I had been thinking of starting a new thread just to see if someone had found a new quality flex panel.

 

[carld]

I have my setup for two years now. Two KINGSOLAR 50W (100 W total) Semi Flexible Solar Panel connected in series with a Viltron Energy Blue Solar MPPT smart charger controller and their MPPT Control/Monitor. The total cost was about $400. The mounting frame is made out of 1/8" x 1" aluminum to match the mounting holes of the panels to the roof screws on one side of the roof. I still use the strong arm method of raising the roof. The panels weigh 2.2 lbs each and the frame is around 2 lbs.

So far I noticed some flakes of the clear coat used on the panels which I clean off every once and a while. The Control Monitor shows battery voltage and current, load current, solar panel watts and solar panel voltage plus a other stuff I don't look at. In two years I have never had any electrical problems and the peak output on sunny summer days is around 60W.