Hail Damage Prevention Strategies?

I read this article in The Post today, and got my poor little brain wondering - what do you do to prevent the damage? It's just a thought experiment for me for now (we rarely get hail - currently!). This quote blew my mind!

Baseball-sized chunks of ice caused damage in parts of Colorado on Thursday, after DVD-sized hail crashed down in Texas earlier this week.

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Off I go Googling, searching here and other places, and really haven't seen any discussion about practical approaches to preventing damage to panels - other than "buy hail rated panels"

There's this article from EcoFlow, of all places, recommending a wire mesh over the panels. Oddly don't show any pictures, and it reads like they want you to drape the mesh over the panels (not sure how that would prevent impact damage!). I would assume you'd want a gap so that the mesh could absorb the impact by deforming/stretching like a spring. No?

The wire gauge, like methacrylate, provides a lower-cost approach to protecting your solar investment. The danger here comes in not securing it effectively enough. Wind could knock it loose if the wire mesh isn’t tightly fastened. Any gap in the mesh would leave your panels exposed to hail. You need the cover to be strong enough to withstand the hail but still flexible enough to bend into place and affix to the panel.

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This article from the DOE interestingly says panels only need to handle 1" diameter stones to be "hail certified", and just talks about thicker front glass.

Modules only need to pass a test where they are visually undamaged and lose less than 5% of power from 11 ice-ball strikes at 51 mph of 25 mm diameter (1") hail to be "hail certified."

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Prayer.

Mount them closer to vertical.

Hail defense strategies:

1. Buy hail rated panels, or at least ones with thicker glass. 3.2mm is much better than 2.0 mm panels. I have seen some panels rated for 50 mm hail.

2. Buy smaller panels. The glass is better supported than larger panels. Staying about 400 W class seems about right.

3. Install panels at higher angles. A panel at 45 degrees survives better than one at 20 degrees. Higher angles also self clean better and even out generation year round better. This may not work for roof mounts, though, since the roof angle is given.

4. Buy inexpensive panels and accept that panel replacement might be an outcome of a very bad hail storm. Most of the system cost isn't the panels any more. If you buy a complete second set of panels and put them in storage, you are guaranteed not to need them.

5. Live where hail is rare. Maybe this should be number 1.

One of the odd things I have noticed about hail damaged solar panels is that some panels come out completely unscathed and some panels are pummeled by multiple hits. There are almost never some panels with just one or two hits. Like this:



The only theory I have is that the panels resist most hits until one "big one" breaks a panel, and then the smaller hits can now inflict damage. If a panel never gets that one big hit, then it survives the entire storm.

The above outcome is not rare, seems to happen a lot.



Mike C.

Buy'em cheap and stack'em deep. Buy a bunch of panels and have them ready to go to replace when things break. Only storage then becomes a problem.

kscessnadriver said:

Buy'em cheap and stack'em deep. Buy a bunch of panels and have them ready to go to replace when things break. Only storage then becomes a problem.

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Yes , for the price nowadays, just keep spares.

Tilting vertical would help if your mounting system allows and you have enough notice to go do it.

Any type of cover will just reduce efficiency.

For my trailer mounted panels that are horizontal and can’t be moved, I bought some cheap pool floats (the flat mattress type) that I can throw over the top and tie down. Of course this assumes I have time to do it.

For the rest I just hope for the best. The hail almost always blows north to south, so it hits them on a glancing angle.

I worry more about meteor showers.

seneysolar said:

and you have enough notice to go do it

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There is the main problem ….”when”…..AND ..will this storm produce hail…how big…what will the wind do…will your tilt boost potential wind damage….how fast can you cover and then uncover the array…are you even home to do anything….will you wife run out in the lightning ,wind and rain to cover them if you call her from the office...

Will your envious neighbor sorta smirk and call you at work to inform you what’s happening at yer house…
Yea…that neighbor… you know the one I mean..

J.

While my work-around isn't what one would call bullet-proof, it has proven to be hail-proof... grab some moving blankets (most hardware stores should have them, if not all) and drape that over your arrays. Because mine is mounted on top of my SUV, I also fasten them down with tie-down straps. Once the storm is over, uncover and dry out. So far it's survived me six hail storms.

I'm an insurance adjuster in hail territory... It's extremely rare to have solar panels damaged... my best advise is just make sure you have full coverage for panels... make sure you have the coverage limits upped for other structures if they're not roof mounted on your house.