Flexible Solar Panel Installation

[Zirdu]

I am very satisfied with my solar panel mounts. I have driven to California and back and all around Nevada and Utah this summer. The only issue I noted was that one night with a strong cross wind, the roof made some popping sounds. This doesn't happen driving down the road at 75 mph. It seems like only a strong cross wind causes the noise. Others have noted this issue, expecially with the Grandby, with the longer roof. I don't think it is a problem, just a very minor annoyance under certain weather conditions.

I would not change the screw fastening into the tubing or the tubing size. I did notice that Home Depot or Loews does sell a 3/4 inch square tubing, which might also work well. The small tubing supports in the middle of the panel is just to provide a little support and to prevent sagging. I did NOT put screws in the middle of the panel, just used VHB to attach the center square support to the roof, and sikaflex to attach to the panel. If I have to remove, ii should be easy enough to lift up and remove the center support with a knife. So far that center support is still very solid.

As noted, I did add two more panels to my roof. In the picture below, the new panels are the shorter ones. They might look wider, but all four panels are exactly the same width.



In these 2 new panels, I used a slightly different method to stiffen the sides of the panel. Instead of a 1 inch by 1/16 inch flat bar, I used a angle piece of 1/2 inch per side, by 1/20 inch, with one side sticking up.



I had to use small 1/2 inch flat pieces to build out the bottom to make for solid platform for attaching to square tubing.

Finally, here is a detail of the screw in the center front mount.



The weight of the flexible panels alone is about 4 pounds. The total weight of the mounting, including all tubings, bars, screws, VHB tape, etc, is 1 1/2 pounds, so the total weight of the panel with all mounting is 5 1/2 pounds. I have no problem lifting the roof of my Grandby myself (age 71) with the extra 22 pounds. (I do have the exterior lifter things.)

 

[bike4mee]

This is nice but I try to park in the shade and if you have SUP's/ things carried on your roof you get shadows. From what I understand any shadow on a solar panel will stop the flow of electricity. I need a rollup soar panel that I can have on a leash to be placed in the sun. Is there a thread for that type of solar setup?

 

[ckent323]

Bike4mee,

You are correct that shade, even a small amount of shade on a solar panel can significantly reduce its performance.

However, an upside to the solar panels that are mounted with a small air gap between the panel and the camper roof (typically rigid panels) is that they shade the camper roof and significantly cut down on the heat load.

Craig

 

[Karlton]

I like the mounting method. Thanks, Zirdu for posting. What solar controller are you using for the system?

 

[Karlton]

I like the mounting method. Thanks, Zirdu for posting. What solar controller are you using for the system?

Found it in another post on the topic!

"I wired the two in series, making the supposed maximum voltage of 45.6 volts. These are wired into a Victron100/300 MPPT controller. The 100 means it can take up to 100 volts max input, and the 30 means it can output up to 30 amps. "

 

[Vic Harder]

Victron makes great gear.

 

[Zirdu]

As I noted in my initial post, I tried to make the installation somewhat reversible, so that if I had to, I could remove and replace the panels. I didn't expect to have to do this, but as I noted on another post, I damaged the panels by driving into my garage with the back of the roof up. This scraped off the connector on the top of two of the panels. I tried to repair them by soldering them back together, but I was ultimately unable to fix one of them. It had torn off the small connector below the plastic, and I just couldn't get to it to solder it back.

So I just went through the trouble and expense of removing and replacing one of the 120 watt flexible panels. It was fairly easy to do. I just unscrewed the panel, and then carefully cut it off the mounts, leaving the mounts mounted securely on the roof. In doing this, I noted how securely the mounts were mounted to the roof. They are not coming off unless I do a lot of work to cut them off.

I then cut off the wires and removed the old panel. I prepared the new panel by securing 1/2 inch by 1/20 inch angle aluminum on the sides, and 1 inch by 1/16 inch on the front and back with VHB tape. I then secured the new panel onto the mounts with a little Sikaflex 221 and weiighted it down for a few hours for the Sikaflex to set up. I then screwed the panel down to the existing mounts with #8 x 1/2 inch self drilling Lath Screws.

Hopefully this will be the last time I have to do this! So far, everything works pretty much in accord to expectations.

 

[pghjon]

The new panels FWC is using supposedly work better in shade.

https://overlandsolar.com/collections/off-grid-cabin-solar/products/145-watt-semi-flexible-sunpower-gen-3-panel

 

[moveinon]

I have a 160W Zamp suitcase portable I bought used off of CL pretty cheap. It is made in Bend, Oregon and is very solidly built and can easily be set up and tilted at whatever angle best takes advantage of the sun. I clamp in on my aluminum roof rack when in transit or camped in the sun and it functions just like a fixed roof top solar panel. But like others have said I try to camp in the shade a lot of the time and in that case I just unclamp it from the roof rack, plug it into the back of the Fleet, add the extension cord and use it as a portable out in the sun. Kind of the best of both worlds.

 

[pvstoy]

Ok I will double post here also info what FWC is using . Other post "What brand is the 160 watt solar panel fwc provides"

http://www.wanderthewest.com/forum/topic/15718-what-brand-is-the-160-watt-solar-panel-fwc-provides/page-5#entry195051

Posted Today, 12:50 PM

I can answer that question for you. I was at FWC last month and saw the new panel that is being installed. I was impressed and contacted Overland Solar for details.

I talked to Rando and he pointed out that the specifications provided on the web page is wrong. So talking to Brian at Overland Solar I got the corrected specifications.

22 X 57.25 inches
7 Pounds
Pmax 160W
32.2 Voc
27.3 Vmp
Isc (A) 6.8
Imp (A) 5.83

FWC started installs at the beginning of the year when the new owner took over. Mainline Overland also stocks the panels.

How they are mounted is a aluminum frame with a air gap under between the roof and aluminum angle. On the long sides there are 5 metal grommets on each side and screws are used to attach to the aluminum frame. There has been lots of testing to see if there needs to be a thin backing plate to prevent warping or sagging. As it turns out they are ridged enough that nothing is needed. But a caution for my install for mounting the panels North / South between the two roof vents was air flow getting under the panels while driving. If I do see any wind ( not likely) then a simple poly air deflector will solve it.

I ordered 3 panels and since they have a higher voltage I'm choosing to use a MPPT controller and wire them in parallel to get more amps. Also Overland Solar provides 90 degree SAE plugs to FWC.

Talking to Brian at Overland Solar I was impressed with his customer service. They live off the grid and use and test their products. They are busy and travel a lot to shows and events where I needed to leave a message and they will get back when available.

Hope that answers your questions.....

 

[rando]

Are they also installing what appears to be a rebranded Victron MPPT solar controller, sold under the overland solar name?

 

[pghjon]

not sure....that would be cool, especially if it had the bluetooth option.

 

[Karlton]

Here is the MPPT on their website...no details on the manufacturer.

 

[ckent323]

That sure looks like a Victron 100/30 MPPT Controller

 

[MrCrash]

Agree, looks like a rebranded Victron. I have the Victron controller in my Fleet flatbed and love it. Their app is awesome. All the info I need and then some, but easy to use. I have a new Zamp controller in another camper and it is a POS compared to the Victron. Zamp is not even in the same league. The connectors have microscopic screws to attach the leads, very limited data. The Victron can be mounted out of sight which is great too.

 

[pvstoy]

If I can remember correctly, Brian at Overland said that they have a guy (electrical engineer) that has designed their controller guts. So yes the case looks like Victron but not sure what is different.

 

[rando]

Looking at the manual - it looks like it is copied straight from Victron. That would definitely be an in improvement from Zamp, but it seems like it would be even better just to use the original OEM from Victron, so you know it would be supported by Victron.

 

[Zirdu]

Update on my flexible solar panels: My flexible solar panels I installed as indicated in this post have lasted 7 years. They were still performing adequately, until my garage door failed to raise all the way to the top and I broke off one of the junction boxes at the top. I have tried to fix these in the past and it seems pretty much impossible to me.

Luckily, I had a spare SolarCenergy 120 watt panel from years ago. It was easy to remove the damaged panel. In installing the new panel, I omitted the step of attaching aluminum stiffening bars to the bottom of the panel, and I did not even use screws to attach to the 1 inch square mounts. I just cleaned and sanded the mounts, which were all in perfect condition with no failures, and used VHB tape to secure the panel to the 12 1x1 mounts. I now think the stiffening bars, and the screwing down of the panel into the 1x1 mounts, was overkill. That VHB tape is really amazing, and the new minimal mounting method seems to be working fine.

I just tested it out, and on this late September day in Southern Utah, I was getting 244 watts at about 1:00 PM. Recall that my array is a nominal 480 watts. So today I got 51% of rated performance. In middle of summer, at high altitude, I expect I would get a lot more. This is acceptable for me. My philosophy is to install a lot more solar than you think you need, since in real life use, you always get a lot less than rated capacity.

 

[Wildcat]

Zirdu, thank you for the update! I previously tagged this thread that you started years ago because my intent was to install solar and use your method of attaching flexible panels. I want to use the lightweight flexible panels for the same reason you did, to reduce weight on the roof. And I'd rather use VHB and avoid putting holes in the roof. I'm hoping to install solar on my camper this winter when I have some down time.

My biggest concern with your method was the possibility of introducing some flex or flutter in the panels from air passing under and over the panels while driving at freeway speed, which could affect the longevity of the panels. Since you have not experienced any panel failures I would say that my concerns are not valid. Do you think the angled aluminum bar provided any benefit to not allowing air to get under the leading edge of the panel? I believe you are calling that piece of aluminum a stiffening bar, is that correct?

 

[Zirdu]

Thank you wildcat. Yes, I initially added the angle bars and flat stiffening bars to the bottom of the flexible panel to avoid the possibility of flutter of the panels at high speeds. They certainly did do that. But they are a lot of work to install, and I am thinking that they were not necessary. I can't see the panels while driving of course, so can't really tell what is happening up there at speed. But I open the window and don't hear anything, at least. I think the flexible panels are strong enough so the extra stiffening is not necessary. I guess I I will find out! Note I do have mounts in the middle front and back of the panels, and one in the middle, which I think help a lot to keep the panel from flexing at speed.

By the way, I always keep my camper parked in my garage when not in use. i think the main thing that wears out the flexible panels is sun damage over time. And heat, if you have them mounted directly on the roof without an air gap.