Protecting Solar Panels

atravis4 · 09-22-2018, 03:56 PM

You folks that put solar panels on your roofs, How do you attach them and how do you protect them while underway? I would think some type of rubber/silicon mounts to decrease the amount of vibration transferred from the bus. The other thing I want to know is do you cover protect the panels when driving?
Thanks
Alan

Hotpuppy · 09-26-2018, 09:01 PM

I would recommend mounting some sort of rails. Use a polyurethane sealant such as 3m 5200 which is slow to cure but relatively permanent. Unistrut comes in a half heigh configuration and would be reasonably sturdy and easy to mount. This would let you mount the rails to your frame bows and the panels to it.

Shouldn't be a need to cover. Worst they are going to see is a 60 to 100 mph wind most of the time. They all should be fine with that.

atravis4 · 09-27-2018, 07:48 AM

Thanks for replying

JDOnTheGo · 09-27-2018, 08:37 AM

I've installed three sets of panels on two RV's and my current coach. First had Z brackets screwed into the roof. Second had large foot angle brackets glued to roof (3M 5200). Coach has angle brackets riveted to steel chassis structure. None of them ever moved.

I can see no need to rubber isolate panels from the roof.

No cover needed. A bus/coach going down the road has got to be forming a huge bubble of air with a very thick boundary layer (IMO). I've never seen a CFD analysis so no facts though. Stick your hand out the roof escape hatch while moving and you'll see what I mean. I suspect far higher wind loads are seen during a thunderstorm than on the highway (typically).

o1marc · 09-27-2018, 10:17 AM

How do panels fare in hail storms?

Dagnythedoodle · 09-27-2018, 10:28 AM

Quote:

Originally Posted by o1marc

How do panels fare in hail storms?

Yeah, I'd like to know this as well. Would making a plexiglass cover or something be a dumb solution to this? We just get huge hail storms in my part of Idaho, especially in the summer while I'm in the backcountry working a lot so I wouldn't always know when it's happening.

I'm almost to the point where I'm doing my install and I just spent a shitton of money so I'm trying to be proactive =]

Dead pirate · 09-27-2018, 10:41 AM

I have 4x4's with z clips. 3 years now. Something shattered one of my panels about a year and a half ago. It has not affected anything. I coated it with a spray silicone, but it became opaque. I used a metal brush on a drill to get it back off. It's still broken and works just fine.

Hotpuppy · 09-27-2018, 11:20 AM

Quote:

Originally Posted by o1marc

How do panels fare in hail storms?

This is like asking how hot your significant other is. That's really subjective and depends on many things.

Solar panels are designed to be installed outside, on a roof or otherwise in an exposed location. As such they are intended to be impact resistant.

Hail comes in many shapes, sizes, and forms. It can be "soft" or "hard" and "pea" to "Baseball" sized or larger. If you get soft pea size hail you probably aren't going to know it happened. If you get hard baseball sized hail (very rare) you are going to have shattered automotive glass, dented body work, and homes with holes punched in the roof.

Hail is directional and very localized. A typical hail storm is about 6 miles long and 1.5 to 2 miles wide. The worst damage is at the center. Colorado Springs had a very bad hail storm this year that had large, hard hailstones that did major damage.

Soft hail tends to be like a slushie and is opaque in appearance. Hard hail is clear and like solid ice. Both types of hail tend to make a mark about twice the size of the hail stone.

I would not expect to find damage to your solar panels from hail unless you were unlucky enough to be in a significant hail storm. In that case I would suggest you have other issues and a couple of solar panels is the least of your worries.

Personally, I think you should be more worried about "Top-Flite" Hail from parking near a golf course. It's been known to damage roofs pretty good.

Hotpuppy · 09-27-2018, 11:22 AM

Here is an article about the Colorado hail storm. Out of 3,000 panels at the NREL they had 1 damaged panel.

https://www.energy.gov/eere/articles...e-severe-storm

Iceni John · 09-28-2018, 12:27 AM

I have eight Sharp 255W panels, each in its own support frame made from 1.75" 6063 angle, and secured by four 5/16" SS bolts and washers onto the top edges of the panel's frame: it would take less than five minutes to replace a panel if one were to get damaged. The eight support frames are hinged to a central walkway on one side, and have telescoping/sliding/hinged/pivoting SS struts to the roof on their other side; the walkway is bolted through the roof ribs with 36 3/8" SS bolts, and the struts' support rails are bolted through the ribs with 36 5/16" SS bolts, making a total of 72 SS bolts and NyLok nuts holding everything down. It's not going anywhere! Everything is made from 6061-T6, 6063-T52 or 18-8 SS, with 3003-H22 treadplate for the walkway itself, so nothing to paint anywhere. And the best thing, apart from free power whenever the sun's shining, is that most of my roof is now completely shaded from the sun, lowering interior temperatures noticeably.

John

Hotpuppy · 09-28-2018, 12:55 PM

Speaking of bolts.... I've had really good luck with hardware from BoltDepot.com. It's fairly priced and high quality hardware... unlike OrangBox or BlueBox.

jimburke77502 · 09-28-2018, 07:24 PM

The manufacturer of your panels should be able to tell you about hail. I can't recall the brand I put on my step van, but they were rated up to 1/4 inch hail. They've been hit by hail, but not 1/4 inch, and have held up well. On my next panel set up I plan on doing a double tier rail system and putting 1/8 inch hardware cloth (Just really small chicken wire)about 2-3 inches above the panels to act as a trampoline for anything like hail.

Iceni John · 09-28-2018, 11:15 PM

Quote:

Originally Posted by jimburke77502

On my next panel set up I plan on doing a double tier rail system and putting 1/8 inch hardware cloth (Just really small chicken wire)about 2-3 inches above the panels to act as a trampoline for anything like hail.

You'll lose power production if you shade your panels, even partially or slightly. Panels must be clean to optimize harvest, and even bird poop or a few leaves affect output. I think that chicken wire may have a noticeable effect.

John

Marceps · 10-01-2018, 05:05 PM

Quote:

Originally Posted by Hotpuppy

Here is an article about the Colorado hail storm. Out of 3,000 panels at the NREL they had 1 damaged panel.

https://www.energy.gov/eere/articles...e-severe-storm

This is good info. Thank you for sharing.

kidharris · 10-08-2018, 01:16 PM

Quote:

Originally Posted by Iceni John

I have eight Sharp 255W panels, each in its own support frame made from 1.75" 6063 angle, and secured by four 5/16" SS bolts and washers onto the top edges of the panel's frame: it would take less than five minutes to replace a panel if one were to get damaged. The eight support frames are hinged to a central walkway on one side, and have telescoping/sliding/hinged/pivoting SS struts to the roof on their other side; the walkway is bolted through the roof ribs with 36 3/8" SS bolts, and the struts' support rails are bolted through the ribs with 36 5/16" SS bolts, making a total of 72 SS bolts and NyLok nuts holding everything down. It's not going anywhere! Everything is made from 6061-T6, 6063-T52 or 18-8 SS, with 3003-H22 treadplate for the walkway itself, so nothing to paint anywhere. And the best thing, apart from free power whenever the sun's shining, is that most of my roof is now completely shaded from the sun, lowering interior temperatures noticeably.

John

Do you have access to the bolt heads from inside the bus? How are you sealing them from leaking rainwater?

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