mounting my solar panels

[Darklock]

I have ordered some solar panels to put on my TT. I bought the 200 watt kit from Renogy. I doubt that I will be able to determine where the structural members are, so there is the very real possibility that if I just use screws they will only be into the plywood decking. In any other applications, I would trust this, but not for going down the highway at 60mph. Therefore, I am thinking of using expanding well nuts. Good plan? Or does the collective here feel that the screws should be enough?
Also, what is best sealant to insure no leaks? No clue what the roof surface is. TT is a Gulfstream Conquest.
Bil

[lane_hog]

Mine have maybe 2" underneath and none of the three RV's they've been installed on have caught fire yet...

[TechWriter]

I used two aluminum rails and four L-brackets to mount each of my panels.

[SJ-Chris]

1L243 wrote:
Not to hijack my own thread but was scanning through some RV solar panel mounting projects and notice how much difference there was in the distance between the panels and the roof of the RV. In my case I used Renogy two piece mounting brackets and was limited on the height of the panel.

My roof is curved, the ends of the panels are 3" from the roof the center of the panel is 2 1/2" from the roof.

I read that to allow fro proper panel cooling 3" minimum but 4" to 6" would be ideal.

I was wondering what the consensus would be on panel height?

I'm far from an expert, but... I think most Z-brackets only provide about 1 inch of spacing between the panel and the roof. I'm guessing it is fine. If you've got 2" or 2.5" that seems like more than enough.

-Chris

[1L243]

Not to hijack my own thread but was scanning through some RV solar panel mounting projects and notice how much difference there was in the distance between the panels and the roof of the RV. In my case I used Renogy two piece mounting brackets and was limited on the height of the panel.

My roof is curved, the ends of the panels are 3" from the roof the center of the panel is 2 1/2" from the roof.

I read that to allow fro proper panel cooling 3" minimum but 4" to 6" would be ideal.

I was wondering what the consensus would be on panel height?

[Darklock]

AS mentioned earlier, my need is small. Water pump, a few led lights, cell phone charging and whatever the fridge needs while running on LP. I have installed a DC-DC charger to charge battery while driving, and have a generator to use if really needed. I think I am good with 200W.

[lane_hog]

Keep in mind everyone has their own power footprint...

Someone who only needs minimal recharging to cover their fridge and some phone charging might be just fine with 100-200W of cheap panels from Harbor Freight and a pair of lead acid batteries.

If you're trying to power a residential fridge and keep two laptops and a big screen TV running 12 hours a day, that 900W roof of Freep's might be justified along with a bank of $1000 batteries.

Before spending the big bucks, figure out your amp hours and plan accordingly.

[Freep]

I know you already got the panels but you will likely need more. I have 600 watts of panels(4x150) on my truck camper and I'm thinking about adding another 300.


When picking solar panels for your rig figure out how much space you can use, then pick panels of the largest dimension you can fit in the space with the highest density of wattage per square foot. Those panels will last 20 years, don't go cheap.

[Darklock]

I am using well nuts to hold down the panels. The reason I am waiting on pollen is for the eternabond tape that will hold down the cables. I realize that a little pollen probably will not matter for these, but why not wait. I am not in any hurry, and I wrenched my back two weeks ago and am waiting for it to get better.

As for the wiring.... I plan on running the wires down the the roof near the shower vent. From there under the kitchen sink, behind the fridge and come out to the controller that is mounted at the end of the cabinet. Wires from battery to controller run along bottom of trailer and come through floor behind fridge, then up to controller. This allows me to not have any of the cables visible.

[lane_hog]

Do you have a solar prep for the wiring? If not, what's your plan?

[Almot]

I would not trust any adhesive to hold solar panel to rubber-ish coated plywood. This membrane is thin and in some places doesn't adhere to the plywood if you look close. It has very little strength on its own, its only purpose is to protect the plywood from water ingress. If solar panel starts moving it will rip a piece of membrane off the roof.

You already have dozens of screws in that plywood, another dozen won't make it worse. Use #10 stainless sheet metal screws, with Dicor sealant under the brackets as described. There are different kinds of Dicor, you want this one: https://www.amazon.com/gp/product/B004A2YKWI/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1. Put a generous coat of Dicor under the bracket so that it would ooze from under the bracket edges when you put the screws in. Lubricate screw with Dicor, drive it in, cover the screw head with Dicor. You don't have to cover the entire plate.

[Darklock]

I have not mounted them yet. Wash the roof and by the time it dries, it is covered with pollen again. I will wait till after the pollen is done falling. I hate the pollen around here. Everything is yellow.

[lane_hog]

Hope it went well. I was lucky on our roof that I could see and measure the structural members from the inside after removing the vent shrouds. No question that I'm in a rafter vs. just the roof.

[Shadow_Catcher]

Ed_Gee wrote:
3M double sided VHS tape, No. 4950, is probably holding many thousands of solar panels on RV roofs for years - and not a single report of one ever not working. The best leak seal of all is no seal needed.

Ours has been up for 12 years, however you have to have enough surface area and do proper surface prep. Wind loads in excess of 120MPH

[1L243]

Something to think about when deciding how many bolts/screws to secure your panels to the roof. I was watching a couple of youtube videos on boondocking and one guy was camped in the California desert and a 80+ mph wind/dust storm kicked up for many minutes. It blew his antenna and vent cover off the roof. He did not have solar panels on his roof but if he did I thing they would have been gone.

Another video a couple heads off into the National Forest and comes across a washboard portion of the dirt road. It was enough to rattle your filling out.

If you not planning on going off paved roads it may not be that big of a deal. Although several years ago I was heading across New Mexico and a freak windstorm came up. We got off the freeway and found a nice protected RV Park. We got blown around pretty good. Later we learned that they closed the freeway and several big rigs were blown over.

Kinda make me glad that I put the extra screws in my panels...