How safe are roof mounted solar panels

Roof mounted panels Work as long as there is solar energy to harvest
The controller will determine how much charging will be added, when other power is available
Example
The Blue Sky 2000e MPPT solar controller I had on there for just over four years , would always be on and add something to the system

But the Xantrex C40 PWM controller shuts off when my converter reaches over 13.8v, solar output is ZERO

It does charge when I'm driving

My DW doesn't want me on the roof, so this may be a moot point. But I have filon too. What would I do to secure it, screws and dicor only?
Also, do the roof mounted panels keep your batteries charging and or topped off while driving?

Shadow Catcher wrote:
The roof on our teardrop is Filon and our panel large. I did not want to drill holes and found ABS mounts that I imported from China. I called 3M and talked with one of their engineers about the use of 3M VHB tape and how much surface area on the mounts and surface prep I would need. He made a recommendation which I followed to the letter.
Three years ago we took a trip to California, hit those 40+ MPH head winds at 70MPH with trucks passing in the other direction. Wind loads, way up there and held on with tape.

For a number of years, Escape used VHB tape to mount panels on their fiberglass "egg trailers". My panel has been up there for 4 years with no problems, but they did have one blow off a trailer, and have since switched to epoxy.

I can't even imagine the brackets letting go at any speed, but what keeps those hand tight black knobs from working loose, kinda amazes me.

75 mph ??? My tires come apart at 55, how would I ever get to 75 ??

Filon is a different creature.
In rubber/plywood you have to use screws. Yes, sealant alone is almost enough to hold it to the rubber, but the rubber itself doesn't hold well to plywood, so the whole thing with mounts may fly away with pieces of rubber still attached to the mounts :)

I used screws and sealant just like Fred said. Probably overdid it, with 5 screws where it was ply alone and 4 screws where there was a rafter (2 in rafter and 2 in ply). Locating rafters makes sense, but it's not easy, and sometimes they are not in the right place. Some of my brackets are 4" tall to clear the plumbing vents, and panels are big, 39"x65". Unfinished panel with one leg "floating" (no screws or sealant) stayed through the summer in hurricane Odille, the worst in years, panels ripped off the houses, - mine didn't even budge.

The roof on our teardrop is Filon and our panel large. I did not want to drill holes and found ABS mounts that I imported from China. I called 3M and talked with one of their engineers about the use of 3M VHB tape and how much surface area on the mounts and surface prep I would need. He made a recommendation which I followed to the letter.
Three years ago we took a trip to California, hit those 40+ MPH head winds at 70MPH with trucks passing in the other direction. Wind loads, way up there and held on with tape.

Hi,

I used 3 screws on each of my roof mount brackets, and they have stayed in place for well over 18 years. I also have not read a complaint about a solar panel flying off. The sealant used between the bracket and roof is almost enough to hold it in place, but new I also have 3 small #10 screws into the thin 3/8 plywood under the roof, and have a roof coating going over all the roof membrane, so that also prevents me from removing the panel mounts.

Good luck with your installation, and don't worry about them leaving.

Fred

Sagecoachdriver wrote:
Doesn't look like the 2 screws for each of the 4 mounting brackets are secure enough to handle driving down the road at 75mph in Utah and have wind to boot.

2 screws in each bracket should be enough, unless your brackets are taller than 5 or 6". Still, I wouldn't pull my trailer at 75 mph, no matter with panels or not. With motorhome - maybe so, it has a different dynamics.

Don't listen to what SMK says about one screw per each corner. Like they say, "wise people talk less" ;)... IIRC, his design is pretty solid, there is more to it then just 4 brackets. He's got 2 aluminum bars across under the panel, and then screws going through these bars at the ends.

The box breaks the wind. Just a few swirls and eddies close to the roof.
BTW I have but one screw at each corner and the large panels are mounted to catch wind on the broadside :E

Moved from technology
Considered putting it in the Class A forum, since it is a Speed question