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I have mentioned the local panel tracker near me that has a problem with snow. All Earth Renewables makes this tracker which is sold mostly in VT as the state subsidized the cost (the CEO effectively wrote the solar legislation). They do have problem that they just were not designed for any considerable amount of snow accumulation. The first snow of the season was 22" and it appears to have stuck on the panel until it rotated during the night towards the morning starting point. Looks like the snow slid off and stalled the unit. In past years the snow just gets high enough on the ground so that it tries to plow the snow and then stalls. Its a seasonal home, but at least they could turn the tracking off in the winter and let it stay facing south. tracker_snow_slide.jpg
Next Shot is at my house after the same storm. The front roof is fairly shallow so it holds the snow. The Hot Water Panels on the left were originally installed flush to the roof but it meant way too much hot water in the summer and less in the spring and fall. I rotated them up to about 60 degrees and they work much better. The trade off is when snow covers the panels, the snow slides down on the cold roof and piles up blocking the lower part of the panels. Unless I want to get on a ladder raking them off is difficult unless its light powder right after a storm. The PV panels on the right were raked off. If I do not rake them, they will stay covered with snow for weeks. If I can expose the roof at the base of the panels and the first foot or so of the lower panels they will eventually melt off but unless its a real warm sunny stretch its easy to get a lump of snow in the wrong place to knock out the string. You can see the lump overhanging one panel and that is enough to drop output. SHW_snow.jpg
My DC modified DC solar trailer is semi permanently parked in the front yard. It has 20" of snow on it. I have to be careful raking it off as its fine loaded uniformly but its not braced to be half cleared and half covered so it rake about half the depth off first. With the 20" of snow and the surface area the resulting lump at the base of the array was about 4" feet high. You can see the snowblower track in the foreground. I cut it to get to the panel initially and then need to go back after I rake it and clean out the mound. Snow that has slid is lot harder to snowblow than virgin snow. trailer_snow_small .jpg
Anyone else have pictures of panels with snow?. Universally salesfolks understate the impact of snow on production. They seem to always claim that they will melt off nearly instantly.
BTW when snow slides off the roof array it misses the 4 panels of my original array as long as they are set at winter angle of 30 degrees.
Next Shot is at my house after the same storm. The front roof is fairly shallow so it holds the snow. The Hot Water Panels on the left were originally installed flush to the roof but it meant way too much hot water in the summer and less in the spring and fall. I rotated them up to about 60 degrees and they work much better. The trade off is when snow covers the panels, the snow slides down on the cold roof and piles up blocking the lower part of the panels. Unless I want to get on a ladder raking them off is difficult unless its light powder right after a storm. The PV panels on the right were raked off. If I do not rake them, they will stay covered with snow for weeks. If I can expose the roof at the base of the panels and the first foot or so of the lower panels they will eventually melt off but unless its a real warm sunny stretch its easy to get a lump of snow in the wrong place to knock out the string. You can see the lump overhanging one panel and that is enough to drop output. SHW_snow.jpg
My DC modified DC solar trailer is semi permanently parked in the front yard. It has 20" of snow on it. I have to be careful raking it off as its fine loaded uniformly but its not braced to be half cleared and half covered so it rake about half the depth off first. With the 20" of snow and the surface area the resulting lump at the base of the array was about 4" feet high. You can see the snowblower track in the foreground. I cut it to get to the panel initially and then need to go back after I rake it and clean out the mound. Snow that has slid is lot harder to snowblow than virgin snow. trailer_snow_small .jpg
Anyone else have pictures of panels with snow?. Universally salesfolks understate the impact of snow on production. They seem to always claim that they will melt off nearly instantly.
BTW when snow slides off the roof array it misses the 4 panels of my original array as long as they are set at winter angle of 30 degrees.
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