How to attach a Solar Panel? - RV-Dreams Community Forum

Old Snipe · RV-Dreams Family Member

How to attach a Solar Panel?

blijil · RV-Dreams Family Member

Screws are the only way I know to handle the forces on a solar panel mounted on the roof. Sealing the hole depends on the roof type but most vendors provide a material to put under each mount (to prevent edge cutting) and a roof sealant appropriate for the roof type. At least 8 and sometimes 12 screws per panel depending on weight of panel and mounting bracket size.

I'm with you I don't like it but I can't thing of a better alternative.

Larry

bjoyce · RV-Dreams Family Member

If you have a fiberglass roof you can use the high end 3M double-sided tape. This is not something you get at a normal hardware store, but it is available. Our panels were mounted using it by AMSolar, http://www.amsolar.com. The tape is basically the equivalent of double-sided Eternabond, often used to seal connections on RV roofs, which last forever and is very strong. Believe me, it is strong enough.

Jack Mayer · RV-Dreams Family Member

I've installed many panels - dozens and dozens over 8 years. I've never had one come loose.

Like Bill said - on a fiberglass roof you can use the 3M tape. It WILL NOT come off. Period. But you need to install it correctly.

On a rubber roof I use self-leveling caulk under the mounts, and 2 screws per mount - that is a total of 8 for the panel. Use caulk on the screw threads and cover the screw heads with caulk. You will never have a leak or a problem.

Tmcblane · RV-Dreams Family Member

Hey Paul, great to run across you on a different forum! Great answers here. I did as Jack said and used Dicor and a couple of screws. If you have rubber roof be sure to clean it real good before applying the Dicor. Aluminum or fiberglass would be even a better setup. If your going to frequent the desert I would be sure to make them tiltable. The sun is pretty low in the sky during the winter and tilting them was the only way we made good power. Difference between tilting and not was double the amps from flat!

Old Snipe · RV-Dreams Family Member

Hey Tab!

Good to hear from you, too! Thanks for the info, I'll have to look at the tiltable version, did't realize you can double the input. Wow. That could cut down on buying extra panels.

Hope you can break loose from OH soon and hit the road.

Best Regards to you both!

Paul (and Marti)

Jack Mayer · RV-Dreams Family Member

You won't double your input by tilting - unless other factors are at play. But you should easily expect a 25-30% increase if you do it correctly. It can replace an extra panel in most size installations. If you spend long times in one place, with good sun, it is worth doing. You just have to watch the wind load. I have seen panels ripped off by wind from behind.

Tmcblane · RV-Dreams Family Member

Jack and Paul, he is right. I got my thinking twisted up. When laying flat I was getting 18 amps of charging in the morning, by tilting towards the sun it increased my input to 28 amps. Certainly not double but a pleasant increase of nearly 55%.

Old Snipe · RV-Dreams Family Member

Jack Mayer wrote:

You just have to watch the wind load. I have seen panels ripped off by wind from behind.

So Jack, were these panels screwed on or taped on? I have a FG roof (Winnie) and like the idea of tape vice screws.

And 30-50% increase by tilting is certainly worth looking into.

Best Regards!

Tmcblane · RV-Dreams Family Member

Paul, I certainly would not be concerned with using the tape. Especially if it is like Eternabond. As long as it does not get soft in the heat. Good think is fiberglass will make a good surface for a tape. Actually Dicor sealant would most likely be sufficient. We we had our motorhome it had an aluminum roof and that is where I originally had my solar panels mounted. I had made brackets out of 1 x 3 aluminum channel and used SS hinges to tilt. Anyway before I fastened the channels down I used silicone under them to seal them. We I went to take the panels off I ATTEMPTED to remove the channels and there is no way in hell they were coming off! It started to deform the aluminum roof as I pull on them. Silicone is a great adhesive but is no good on rubber roofs. Heck you can't normally remove the stuff with a razor blade. So I understand not wanting to use screws and I don't think there is a problem with that.

As for tilting the panels, as you know it was quite windy in Quartzsite when we were there so I had to make sure I had the panels fastened with screws when tilted. They can certainly become a heck of a wing in strong wind. Something to be aware of.

Tmcblane · RV-Dreams Family Member

Did any of you guys see the mounting system for solar panels at Quartzsite that were designed to follow the sun? Neat concept but as I recall they were pretty pricey. Like $500 per mount or so, but I think you could mount (2) 120 watt panels to one.

Thom · RV-Dreams Community Member

I saw one in Quartzite hooked up in the bed of a pickup. spent some time talking to the guy. He claimed it was a totally new concept tracking and all but the tracking concept has been in application for years. For what he wanted for his little system one could put together a much larger one with better tracking than he was using. I think he was trying to re-invent the wheel and get some application specific patents on it. Even saying that, it was built fairly well. the biggest problem I saw with it was that it took up the truck bed. When we were thinking of going with a motor home we were going to build a car hauler trailer to tow with a tracking solar system built in as the roof. but alas we went with a fifth wheel instead

blijil · RV-Dreams Family Member

For the cost of a tracking you can add a panel and almost make up for the difference. If you are willing to tilt you already have made up most of the difference if you are in a good position. If you size about 75 watts of panel per 100 amp hours of battery storage you probably have plenty unless you have several consecutive cloudy days. A small generator can handle that problem.

So in terms of weight, cost, and effectiveness I would think that tracking isn't worthwhile to most RVers.

THat's my Opinion. You are entitled to your own.
Larry

Richard Noble · RV-Dreams Community Member

I've just finished installing a solar panel to the roof of our '07 Challenger. I used 4 brass door hinges (rounded edge)- about 4 inches each - and screwed them to the roof, mounted on and covered with Dicor caulking. I attached the other side of each hinge to the frame of the panel with a bolt. This way I can, by detaching one side (two hinges) tilt the panel any one of four ways. I then attach two angle irons to the hinges and then to the upright side of the panel at a correct tilt - about 50 degrees. In addition to the bolts, I also put a spring pin into each hinge through the panel when the panel is flat for safety when traveling.

Richard Noble · RV-Dreams Community Member

I had to add one more comment -- the solar panel is not working. Think it could be the foot of snow on top of it?

DagoRanch · RV-Dreams Family Member

LOL ... Yeah, I don't think snow is translucent enough to allow any sun in

janieD · RV-Dreams Family Member

AH, the limits of modern technology. :)

jhonebhrestom · RV-Dreams Community Member

Recently before few months i built my own Solar Panels for under $100 as well as a Solar Water Heater for just $10. I currently use them to power my 1700 Square Foot home.Is that really exclamatory or not.

-- Edited by jhonebhrestom on Tuesday 27th of April 2010 04:18:29 AM

wintersun · RV-Dreams Community Member

Adding a solar panel at $300-400 is not cheaper than adding a tilt kit that is going to cost $80 per panel and in many cases with RV's there is a very limited amount of real estate on which to mount panels and their often large 40" x 60" size makes it difficult to squeeze in extra panels. It someone has a 5th wheel then adding more panels is an option but seldom is for most Class C motorhomes, travel trailers, or truck campers.

I would not be worried about replacing a panel in my RV's "lifetime" as the panels will handle golf ball sized hail and have an expected life of 25 years. Who holds onto an RV for that long?

I only wish that the RV manufacturers would catch up with the times and start building combiner boxes into the roof and adding heavy gauge wiring from this location to the location of the house batteries. Every solar installation on an RV is a custom addition which makes no sense in 2012.

makntracks · RV-Dreams Family Member

You're right wintersun. My husband and I were just talking about that. I am really surprised it's not an optional upgrade that can be purchased from manufacturer.

Jack Mayer · RV-Dreams Family Member

Many manufacturers offer solar prep. The issue is that they usually do not provide a very good solution, technically.It HAS gotten a "little" better over time, but most solar prep packages still need "rework".

Bill and Linda · RV-Dreams Family Member

Jack Mayer wrote:
Many manufacturers offer solar prep. The issue is that they usually do not provide a very good solution, technically.It HAS gotten a "little" better over time, but most solar prep packages still need "rework".

Jack:

After seeing some recent electrical “prep” packages on some new, high-end units, I can say that they need "rework” is sort of like saying the Grand Canyon is a little ditch.

Good point.

BTW, we're at your old stopmping grounds at Arches and the new solar is working quite well for us. Glad we did it. It's been so nice.

Bill

Lucky Mike · RV-Dreams Family Member

Cindy .....Installing solar panels on a rig will depend on size , power consumption,battery banks and a few other variables..........estimate on a good to excellent system and this will very on inverter size..............1800 to 5000.oo

first find out what you are going to install it in.....then are you going to be fulltime boondocking or just here and there durring travel times......all this will come into play. Remember solar systems are exspensive and take a long time to recoup your investment.

hope this helps...Ive included a random site to help you get the basic idea

http://www.outsidesupply.com/rv-solar-guide.aspx

Edit by moderator: Activated link. Terry

-- Edited by Terry and Jo on Thursday 27th of September 2012 08:38:56 PM

shystywolf · RV-Dreams Family Member

Ok I now have a question... lol... I live close to Houston Tx. does anyone know of a good place to go to have solar panels added to a rig? and what are the price ranges of having it done. I know each place will have diffrent prices and the sizes also play a key in the price. but any info will help. Thanks again.

shystywolf · RV-Dreams Family Member

smile Thanks mike. the info is a big help. I am planning a budget and this info helped a lot.

Terry and Jo · RV-Dreams Family Member

Cindye,

A good place for research will also be on Jack Mayer's website. Jack is one of the participants here on the forums. Here is a link to Jack's website:

Jack Mayer Website

A number of others have spoken pretty will of AM Solar. I'll let you do the looking there and just provide a link to their website.

AM Solar

Terry

Deborha · RV-Dreams Community Member

Morning All,

I will be installing at least two 100 watt flexible solar panels to the roof of my RV. I do like the idea of not having to drill holes in my roof. I'm not sure if my roof is fibreglass or some sort of hard rubber. Does it make a difference if using the tape? Bjoyce, what is the name of the 3M tape? Is Dicor sealant to attach to panels or to seal them around the edges like caulking? The panels are very thin and light, so maybe the tape would work best. Would I need to cover the entire back of the panel with tape or around the edges and middle- then seal it? I don't want water to get under the panels.

Suggestions are welcome! Shall be an interesting DIY project!

Thanks, Have a good day!!!

bjoyce · RV-Dreams Family Member

It is called 3M VHB tape and you will find lots of hits with an internet search. The problem is getting it in small quantities.

bigboomer · RV-Dreams Family Member

Debbie,

Here is a link to where you can purchase the VHB tape. The company I work for uses this and believe me, once stuck, you are not removing it as long as you cleaned the surfaces correctly (isopropol alcohol).

http://www.amazon.com/s/ref=nb_sb_ss_i_0_11?url=search-alias%3Daps&field-keywords=3m+vhb+tape&sprefix=3m+vhb+tape%2Caps%2C324

Good Luck,

Les

Jack Mayer · RV-Dreams Family Member

The VHB tape works very well. And you do not need to go overboard with it.

You may have a special situation that requires use of the flexible panels, like Unisolar panels, but in general if you can use another panel type you will find them cheaper and more efficient. But there are times and places for using flex panels.

Deborha · RV-Dreams Community Member

Thanks Bill and Les for the product info- will give it a shot.
Jack you are right about the flex/thin film/powerfilm panels- there is a few out there, I think that I found one that should work.
My RV is not very big, and the roof does not really have a lot of open space. There is two vents, the AC/Heater and a fan. Plus the edges have a bit of a curve so there is not a lot of space. I found these mono-crystalline panels that are semi flexible- mostly used on boats. The cells apparently have a 22% efficiency rating, from what I've read this is high. They are a little more expensive- $285 for a 100 watt panel and 50 watt is $150. I was happy to find them as they solved my odd roof issues. I did look at the unisolar flexible film panels- and power film, but they were less efficient and the sizes didn't work.

I'm just now sure how many panels I need- will have to figure it out as I go. I can fit 1-100W and 1- 50W panels- so I think I will start with that and see how it goes. The top of my AC/Heating vent cover would nicely fit a 50 W panel- I just don't know it that is safe or not- do the panels heat up underneath? It would not block any of the venting at the side- if I could put one there that would bump me up to 200 W......

I know it all depends on usage- etc. I will have to try it out and see what works. All suggestions are definitely appreciated!