Hail Stone PV Breakage

I have KC 130 PV modules mounted flat on an RV roof. Thanks to the guidance from the folks here, the system performs beyond all expectations. I'll be going out to Kansas in August. How well do these panels tolerate hail?

Comments

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Hail Stone PV Breakage

    I think they are supposed to be pretty good. Not as well as a 3 layer laminated car windshield, but somewhere in the Mfg's spec, is size of hail it's supposed to take. Marble size at least, and maybe golf ball size. Bowling ball size, you buy a new roof anyway....
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
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  • Mangas
    Mangas Solar Expert Posts: 547 ✭✭✭✭
    Re: Hail Stone PV Breakage

    I don't know what the manufacturers claim but my panels went through a mountain storm last fall.  Fortunately the hail was about pea and marble size with no noticable damage.  

    Apart from panel construction, probably a combination of hail size, wind speed and maybe the angle of the panels all have some relationship too.  In my case the panels were in a reclined position.

    I suppose damage could also show up as shortened panel life.

    Good question.  

    Ranch Off Grid System & Custom Home: 2 x pair stacked Schneider XW 5548+ Plus inverters (4), 2 x Schneider MPPT 80-600 Charge Controllers, 2 Xanbus AGS Generator Start and Air Extraction System Controllers, 64 Trojan L16 REB 6v 375 AH Flooded Cel Batteries w/Water Miser Caps, 44 x 185 Sharp Solar Panels, Cummins Onan RS20 KW Propane Water Cooled Genset, ICF Custom House Construction, all appliances, Central A/C, 2 x High Efficiency Variable Speed three ton Central A/C 220v compressors, 2 x Propane furnaces, 2 x Variable Speed Air Handlers, 2 x HD WiFi HVAC Zoned System Controllers
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Hail Stone PV Breakage

    "I suppose damage could also show up as shortened panel life."

    nope, it will either crack the glass or it won't.
  • System2
    System2 Posts: 6,290 admin
    Re: Hail Stone PV Breakage

    I've often wondered of covering them with a wool type blanket (or two) would offer some protection from hail. Should help lessen the sharp impact. And yes, the angle at which the hail is hitting will be a factor too.
  • System2
    System2 Posts: 6,290 admin
    Re: Hail Stone PV Breakage

    Maybe I should keep some bubble wrap and bungie cords handy!
  • System2
    System2 Posts: 6,290 admin
    Re: Hail Stone PV Breakage

    Common sense would tell me that considering the price of replacing panels, that would be a very good idea.
    Perhaps a cloth sheet over the bubble wrap, because when a hail storm hits, we don't know how bad it will be - - - until it's all over.
    Just call me "Chicken".
  • System2
    System2 Posts: 6,290 admin
    Re: Hail Stone PV Breakage

    The big question is When is it going to hail? I had some yesterday and by the time I could have gotten raincoat and boots on, it had stopped. If the stones were large enough to damage the tempered glass on my panels i think i'd want a hardhat on as well! And convincing the significant other to help throw bubble wrap sheets up and over the panels, in the rain, in the pelting hail...well she might be dragging me out there, instead of the other way around. Cluck cluck. :|

    ralph
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Hail Stone PV Breakage

    protecting the pvs isn't such an easy task. those are interesting ideas on protecting them, but by the time you get out there and cover them it's usually too late. some pvs are not easily reached either. now let's assume for the moment that you can get the wrap or blanket onto the pvs in time. just what makes you think it'll stay there as storms that produce hail are usually loaded with high winds that'll blow your protection and maybe you away? i know i'm not going out there to protect my pvs during such storms as i'm more worried about my own butt at that point. people have enough trouble keeping snows off of their pvs (where it applies) let alone putting blankets or bubble wrap on them. there's also the issue of those that work not being able to go home to do this and it makes no sense to preventatively do this as it prevents pv production for that day.
    we just have to trust the pv manufacturers to give us some strong glass that'll withstand what they say it will. of course it would be difficult to prove that the pv's glass failed due to smaller than speced hail as the evidence will dissapear or errode before many could even reach it. how do we really know which manufacturers are making strong glass to the spec they say and which will honor the warranty without hastles? word of mouth i suppose. more on this would be welcome as i'd like to hear more on both the protection ideas and warranty info as i'm sure others would be too.
  • System2
    System2 Posts: 6,290 admin
    Re: Hail Stone PV Breakage

    :-D Interesting image - - - - people scrambling up ladders, trying to cover their PVs with bubble wrap and blankets at the height of a violent storm.
    "Hey Honey, as soon as this storm is over, remind me to check into those new fangled PVs like Bob across the street has."
  • System2
    System2 Posts: 6,290 admin
    Re: Hail Stone PV Breakage

    My modules are on my RV roof. Even so, by the time I could get up on the roof it would be over, or, so it would be so violent that we'd probably be hunkered down inside riding it out. We've been in some gales perched on the cliffs at Pacifica, CA when the RV was actually rocking on it's stabilizers and that was only 65 mph gusts. At the same place in '98 I believe the El Nino hit and we were parked in a lot next to where houses in Pacifica were going over the cliffs from the storm waves eroding out the cliffs from under them. But, if I were going to store it outside in hail prone areas I think I could button down something to protect them. We're considering moving to the Castle Rock area of CO where I understand there is quite a bit of hail, therefore the question.
  • System2
    System2 Posts: 6,290 admin
    Re: Hail Stone PV Breakage
    HB Phil wrote:
    If I were going to store it outside in hail prone areas I think I could button down something to protect them.

    I think that's an excellent idea, one that has the potential of paying off, if not in monetary ways, then certainly in piece of mind
    Wayne
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Hail Stone PV Breakage

    Lived 30 years in Pacifica--In the same late 1990's storms, had a local "mini" tornado rip the top of a tree next to our home--and had my WWII aircraft (Taylor Craft L2M--basically like a Piper Cub--tail-dragger) blow so hard at Half Moon Bay Airport (exposed outside tie-down) that it collapsed one wing (blowing from the rear) and straightened several links in the tie down chains (I used both ropes and chains--so the plane did not move) bought a set of extra wings and rebuilt one and got it back flying).

    After all of that--I never take for granted what weather/wind/storms/etc. (or earthquakes for that matter) can do to your home and property. That is why I suggest everything be bolted down tight and strong and don't plan on being around to cover/put things away. You never know when something bad is coming your way.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2
    System2 Posts: 6,290 admin
    Re: Hail Stone PV Breakage

    Bill,

    I thought that mention of Pacifica and that bad El Nino year would catch your eye! Glad you were able to get that vintage aircraft back up in the air!

    Phil
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Hail Stone PV Breakage

    On the flip side, got married, had kids, don't have a plane (or a motorcycle) anymore. :cry:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2
    System2 Posts: 6,290 admin
    Re: Hail Stone PV Breakage

    Yep I know what you mean. When I got married I lost my little quirk of disappearing for a couple of years at a time on one-way tickes to Bangokok...
  • crewzer
    crewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: Hail Stone PV Breakage

    The sort-of-standard for the hail impact resistance spec is 1 inch diamter hail at 50-52 mph.

    HTH,
    Jim / crewzer