Solar Panels & Ice Dams

KenZ71
KenZ71 Solar Expert Posts: 58 ✭✭
in Solar Beginners Corner #1
Tried to search for this issue but didn't see much.

As the slow slides off my panels its filling up the gutters which I am afraid will lead to ice dams.

Anyone have similar issues? How do you resolve?

Seems like the easy solution is wire heat tapes but those seem to have mixed reviews.

Maybe I'll get lucky and convince Solar City to do something when they add another dozen panels in a month.
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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #2
    Re: Solar Panels & Ice Dams

    Where are you located and how much gap have you left between panels?

    I'm in Missouri and have hade ice fill the gap, It has never caused problems, though perhaps the slight movement has aided in the sealant/gasket squeezing out onto the glass, unless you're in an area where temps stay below 10 degrees, or so(a guess) or you don't haves days of sunshine, the panels will rise above freezing and melt the ice.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
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  • KenZ71
    KenZ71 Solar Expert Posts: 58 ✭✭
    #3
    Re: Solar Panels & Ice Dams

    I'm located in the northeast. Winter temps usually are around 20 to 30.

    Although the issue is my rain gutters are jammed full of snow. So I am worried about ice backing up under the shingles. Not too concerned about the panels, being a lease if Solar City didn't install them correctly it's their issue to fix.
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  • peakbagger
    peakbagger Solar Expert Posts: 341 ✭✭✭
    #4
    Re: Solar Panels & Ice Dams

    Ice dams are usually caused by what is going on under the roof not on top of the roof. The normal issue is that the section of the roof overhang and the gutters are colder than the area above the main building. With snow on the roof, the warmer upper roof melts and runs down to the colder overhang where it freezes and causes a dam. The gutter is usually even colder than the overhang so that's where the ice starts. Many homes in northern NE remove the gutters but generally the problem just moves back to the overhang. If the roof is vented and the soffits have adequate inlet grilles the roof deck should be the same temp top to bottom. If your attic is warmer than the outdoors you need to install more installation and increase flow through the soffits. Most builders vastly under install soffits vents and many don't put in enough ridge vents. There are also issues with houses that only have a ridge vents. Deep snow blocks the ridge vent and stops the flow through the soffits. I have both a ridge vent and gable end vents.

    I don't think solar panels really impact the situation. Electric heat trace does work well but many folks leave it on all the time. All it really needs is to be on for a couple of hours when the sun comes out when snow is on the roof. Once the water start flowing through the melted channels it tends to stay flowing. Of course some folks just install ice and water shield on the roof deck and the water cant get in but that usually works only if the gutters are off.
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  • 706jim
    706jim Solar Expert Posts: 523 ✭✭✭✭
    #5
    Re: Solar Panels & Ice Dams

    Those ice dams seem to be a big problem where a single story home has been modified to add upstairs bedrooms with no cold air space between the ceiling and the roof. The heat from the bedrooms melts the snow which then freezes at the overhang and the gutters.
    It's been my experience that heat trace cable doesn't help.
    The solution is to keep the roof cold.
    Back to the OP; if the roof is cold, the gutters may freeze but shouldn't cause ice buildup under the shingles.
    Island cottage solar system with appriximately 2500 watts of panels, 1kw facing southeast 1.3kw facing southwest 170watt ancient Arco's facing due south. All panels in parallel for a 24 volt system. Trace DR1524 MSW inverter which has performed flawlessly since 1994. Outback Flexmax 80 MPPT charge controller four 467A-h AGM batteries. Insignia 11.5 cubic foot electric fridge 1/4hp GSW piston pump. My 31st year.
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  • KenZ71
    KenZ71 Solar Expert Posts: 58 ✭✭
    #6
    Re: Solar Panels & Ice Dams

    Thanks for the replies. Been here for 10 years, no problems. Most of the neighborhood homes were built by the same builder, none have heat tapes.

    So maybe I'll just forget about it.
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  • Organic Farmer
    Organic Farmer Solar Expert Posts: 128 ✭✭
    #7
    Re: Solar Panels & Ice Dams

    I live in Maine. Ice Dam problems are VERY common among homes here.

    I am originally from California, I owned a home in Norwich, Ct for 10 years, and finally retired to Maine 8 years ago. I am not native to these issues, but I am learning. :)

    The main theory is un-even heat escaping from the attic. Thermal-imaging and re-distribution of insulation seems to have been the traditional response.

    When I built my house, I put on a metal roof. Metal roofs are now becoming very common. As asphalt composite roofing gets old it is all being replaced with metal roofing in this area.
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  • KenZ71
    KenZ71 Solar Expert Posts: 58 ✭✭
    #8
    Re: Solar Panels & Ice Dams

    Organic Farmer, thanks for the comments.

    Maybe I shouldn't use the term ice dam.

    It just looks odd and concerning seeing snow piled up in the gutters.

    If I had an easy way to clean the gutters or put rock salt in em I would. But these are 3 stories up.
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  • Organic Farmer
    Organic Farmer Solar Expert Posts: 128 ✭✭
    #9
    Re: Solar Panels & Ice Dams

    Gutters are not very common here. Some people try them, we had gutters on our home in Ct. But they eventually filled with ice and the weight pulled them down off the house.

    They do make gadgets to go on top of gutters, in the theory to keep leaves out. But snow and ice?

    My experience has been that gutters get filled with ice, and the weight pulls them down.

    Over doorways it is common here to see small gables made to direct falling sheet ice away from the doorways.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,642 admin
    #10
    Re: Solar Panels & Ice Dams

    Our roofer is recommending metal/steel roofs these days... Asphalt shingles start to fail at 20 years or so--Even the better brands. Relatively sunny San Francisco California Region.

    If you are going to put solar array up and want to forget about it for 20-30+ years--Is it worth thinking of a new roof yet?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • peakbagger
    peakbagger Solar Expert Posts: 341 ✭✭✭
    #11
    In place of gutters I use devices called Rainmasters. They are a set of slats that hang off the fascia boards and redirect water to the ground in wide band instead of in one spot. Not as good as gutters but they don't ice up in most conditions.
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