Drilling holes in trailer roof to install solar: worth it?

[OregonMan]

Hi guys, so for a while now I've been wanting to install solar on my travel trailer. Problem is I'm not very handy, a little on the heavy side and drilling holes through my trailer roof just doesn't sound great.

Do you think it's possible to get the same amount of power generated from solar using the flexible foldout panels? Would it be possible to just use these during the day as we need them, then stow them away, without having to install a bunch of panels on the roof?

I feel like solar tech is improving quickly. Don't want to screw up my trailer and spend a full day working on this if in 2 years Tesla comes out with some amazing portable solar generator. Thanks for any feedback.

[memtb]

I’ve done it on 5 rv’s......a very difficult thing to do, as I’m always afraid that I will not get the hole “EXACTLY” where I want it. I use a plastic electrical junction box to run the panel wires into, and use pvc from the junction box into the rv attic. The junction box is screwed to the roof, with a very generous amount of epdm roof sealant between the rv roof and the junction box! memtb

[jrloucks]

I had a small 60W portable solar panel to start. But I was always worried it was going to 'grow legs' and disappear. Eventually I purchased a 100W rigid solar panel and mounted the panel to the roof of our Class C using some Renogy RNG-MTS-ZB Solar Panel Mounting Z Bracket Mounts.

https://www.amazon.ca/review/R3A3ER2DUE46B5/ref=cm_cr_srp_d_rdp_perm?ie=UTF8&ASIN=B00BR3KFKE

[mr_andyj]

I advise strongly against those flexible panels.
Get aluminum frame glass panels.

The flexible panels have a shorter warranty period for one. Flexing can break things inside, so flex it once and never again.
Putting those directly to the roof means a lot of heat builds up under them, enough to "burn" the roof (get it hot enough to discolor the roof), and heat will damage the panels (degrade them over time). Panels need air under them.

You can certainly use portable panels, but since you have all that roof space just install on the roof. Solar will keep your batteries always correctly charged/topped off so that is a huge plus also.

[mr_andyj]

Called 3M VHB tape. Very High Bond.
Make sure to get a thicker version as it comes in different thicknesses. The thickness is like padding, and thick padding will conform to uneven surfaces better. 2mm should be plenty.
Similar to "double sided sticky tape" but VHB tape is much much much stronger of a bond.

As mentioned above... with rubber roff you will have to drill. Just make sure the screws going through the roof are accessible (not hidden under the panel) so you can re-do the decor lap sealant every year or two.

Otherwise tape on brackets with 3M VHB tape. I bought some aluminum angle iron from hardware store and used that as the mounting bracket, you can buy special brackets too.
For my last project I only had the brackets at the short sides, taped to the roof and I used two self-taping screws at each end to attach the panels (put one screw in on each side before taping so you don't put the brackets too far or too close together.)
The tape hold incredibly. Mine was on metal roof, and fiberglass roof and also a rubber-painted aluminum roof. I have never screwed into a roof (I have never had a rubber membrane roof either tho).

[Vintage465]

IMHO, drilling holes in the roof is a moot point now. We have so many good products from sealing to gathering and penetration design that there is little to worry about from a product or leak perspective. I think the issue is more with your situation is your self proclaimed lack of Handy-ability. I've been on my roof regularly with my weight varying from 215 to 260 pounds and have done no damage. Actually I repaired a broken(cut actually) truss, so my roof is better off with me tramping about on it. It could be possible to minimize the amount of time you're on the roof by using a ladder. Or possibly if you have a buddy that is handy, you could assist him with the work while he spear-heads it.

[Tom_M1]

StirCrazy wrote:
you got to have more pannels on the roof then tht we cant see and thoes folded down ones are just extras..


Steve

I have one 125 watt panel on the roof. Any time sun is hitting a panel it will add to the charge, even the ones on the side.

[StirCrazy]

Tom_M wrote:

StirCrazy wrote:
do you get any charging driving to the next campground that way?

Steve

All sources combine. Alternator, converter, and charge controller for panels. While driving a charge would be coming from the alternator and the solar panels. While parked and plugged into shore power or running the generator the solar panels would add additional charge.

you got to have more pannels on the roof then tht we cant see and thoes folded down ones are just extras..


Steve

[dieseltruckdriv]

I made aluminum angle brackets for my panels. First, put down a strip of Eternabond under the bracket. Next glop some Dicor down, then screw the bracket to the roof, and put a little more Dicor over the screws. It can't leak doing that.
I would also never trust taping a panel to a rubber roof. I also enjoy not having to mess around with anything, and the batteries just get charged.

[Tom_M1]

StirCrazy wrote:
do you get any charging driving to the next campground that way?

Steve

All sources combine. Alternator, converter, and charge controller for panels. While driving a charge would be coming from the alternator and the solar panels. While parked and plugged into shore power or running the generator the solar panels would add additional charge.

[goducks10]

dtappy3353 wrote:
Could you please provide us with your plans and supplies used for the awning solar panels? How did you connect the panels to a battery system?

Thank you very much.

In basic terms.
Panels mount to the roof. Panel wires run to a combiner box on the roof.
From the combiner box run wires to a Solar Controller.
From the Controller run wires to the batteries.

If you have just one panel you can as some do route the wire down the fridge vent or use a vent pipe. Which ever is closer or easier.

My TT came pre wired with a 530W combiner box on the roof so thats the route I went.

The best thing to do is google RV solar panels and start reading or watching Youtube videos. You can spend money like no tomorrow or go the cheaper route. Depends on what you need.

[StirCrazy]

Tom_M wrote:
Here's my solution. The panels can tilted up in place or removed and set out in the sun using extension cables:

do you get any charging driving to the next campground that way?

Steve

[Crabbypatty]

I made angle brackets for my 6 panels. Each panel has 4 brackets for 24 holes and 2 brackets for my circuit box. Drill the hole, fill it with dicor lap sealant, add a generous amount of sealant to the bracket and screw it down. Then add sealant on top of the screw and around the bracket. The sealant self levels for a clean finish. Some rvers drill a large hole for the wires to go into the rv. Same deal, generous amount of sealant around that elec box. I ran my wire down the awning arm then drilled into the bay where the controller and on off switch is.

[dtappy3353]

Could you please provide us with your plans and supplies used for the awning solar panels? How did you connect the panels to a battery system?

Thank you very much.

[goducks10]

I installed four 100W panels on my roof using DIY aluminum clips. 2 hex head lag bolts in each clip. I put butyl tape down 1st, then a thick layer of Dicor over the entire base of the clip. Don't know if I have any leaks but I don't worry about it either. Panels are rock solid.