Hail and solar PV panels.

Discussion in 'Alternative Energy' started by Manny, Apr 5, 2006.

  1. Manny

    Manny Well-Known Member

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    Does anybody have any first hand experience as to the effect of a hail storm on PV panels? Here in Oklahoma we get several hail showers every year with some of the ice balls as big as a hens egg. Is PV only for the more friendly weather areas or are there protective measures you can take? Im brand new to this technology.
     
  2. WisJim

    WisJim Well-Known Member Supporter

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    Back in the late 1980s we had a bad hail storm that punched holes in the asphalt roof on my garage/shop building. It didn't damage my Arco glass-faced PV panels, but did dent the Sovonics thin-film panels that were covered with some kind of thin plastic film. Didn't seem to affect their function, at least not right away. The Sovonics panels are now junk, but I am still using the Arco panels and they are working fine. Some of the current thin-film PVs are very similar to the old Sovonics panels, and might react the same to hail. I have seen newer glass-faced panels that had damaged glass, but it seems to be due to twisting or dropping them during installation rather than hail that was the problem.

    I don't worry about hail and the PV panels anymore, but the wind generator is a different story--I always shut it off it looks like a thunderstorm or other possibility of hail, as those blades spinning into hail could damage the blades quickly. No problem if the generator isn't facing into the wind, though.
     

  3. Jim-mi

    Jim-mi Well-Known Member

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    ..."only for the more friendly weather areas..."

    NO.....please don't look at it that way.

    It would be really fun if somebody put together a "photo album" of some of the darndest places where PV is powering something or other.

    One of the ways a PV pannel is tested is for it to withstand 3/4 " hail in 50mph wind. (I'm quite shure of those figures)

    ....BUT if Ma Nature kicks up her heals........watchout

    can you say Katrina...?....Or Tennessee
     
  4. wy_white_wolf

    wy_white_wolf Just howling at the moon

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    Hail can and does destroy solar panels

    ......Baseball to softball size hail fell around 4:18 pm smashing numerous building windows and government vehicles. The hail also dented numerous satellite dishes and caused extensive roof damage including complete destruction of a 504 panel solar array......

    http://www.crh.noaa.gov/fsd/science/hail970713/index.php

    But it is becoming less and less as better materials are now used. Most manufactures do try and put some kind of a hail rating on there panels. Jim's figures may be right but I seem to remember 1 manufacture claiming to withstand 1.25" hail at 100 mph.

    If you put something up need to check with your homeowners insurance. My insurance company will cover hot water and heating systems but will not cover for power generation. They told me I would have to purchase A rider if I wanted them covered.
     
  5. Jim-mi

    Jim-mi Well-Known Member

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    Yup , If you have got baseball size hail then you've got way more to worry about than a PV pannel.
    So to say no to PV just because "We might.........." That doesn't fly with me.

    I hope no one lets that be an issue against PV ... or wind turbines.

    PS gotta add another thought; Seasonal tilt. If during the time of year when hail is a factor in your area, then the more vertical you can keep the pannels (winter tilt) that will, in a small amount, help the hail "impack".
     
  6. Manny

    Manny Well-Known Member

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    Thanks for the responses. My cost of being on the "grid" right now is fairly low so I figure it would be a long, long time before I could amortize the cost of purchase, maintenance, repair or insurance of any moderate sized installation. I was interested in installing a solar attic fan or solar shed lights, but even with that low of a cost of installation I still feel I could not justify the effort except out of curiosity.
     
  7. WisJim

    WisJim Well-Known Member Supporter

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    A few years ago we had lightning damage to our inverter, and I called our insurance agent (household insurance) to see if it might be covered, as I hadn't ever asked about coverage for any of our system. They paid for the repairs minus our deductible. I was pleasantly surprised, but perhaps should have checked earlier to see if a rider would have improved the coverage. It does vary from company to company, so it pays to find out.
     
  8. fernando

    fernando Well-Known Member

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    I wonder if a layer of hardware cloth mounted a couple inches or so above the face of the panel would interfere that much with light transmission ?
     
  9. greg273

    greg273 Well-Known Member

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    Or how about some thin plexiglass for the 'hail season'? I wonder if that would cut down on light or increase the heat on the panels too much? Yeah, if you got baseball sized hail falling, take shelter IMMEDIATLY, worry about your panels when the tornado has passed. I heard that tornadoes emit radio frequency noise that can be picked up on the lowest band of the radio, I believe the AM band. Supposedly a steady hum can be detected on the radio from any tornadoes within 5 miles. Someone should correct me if I'm wrong, i cant remember if it is the AM or the FM band...
     
  10. Jim-mi

    Jim-mi Well-Known Member

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    It would be interesting to watch the meter to see how big of a drop the hardware cloth would cause.

    I think "Lexan" is even tougher than plexiglass (softer ?)
    But what the heck you could make like *window shutters* to cover your pannels....AND IF...your home and have some warning time to *flip the covers over*.
    You'd make them so that there was a inch or so of air gap to the glass of the module. Thinking that the Lexan could/would do a bunch of flexing with the impact of the hail.
    this should not be to big an issue thermaly...I think.
    Lexan is pricy tho.

    Gee I like my ideas ...I better patent them.............