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How do you deal with freezing rain, or crusty snow that can't be brushed off?

Red Squirrel

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Jan 1, 2020
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I find with climate change we get way more weird weather patterns here now including freezing rain or wet snow. This ends up causing a crust on the panels which cannot be brushed off like regular snow. I have a 400w system on my shed which I just turn off completely in winter but it would be cool to run power to the house and run it year round. Last year I sorta had it running year round to keep the battery topped up but no load. Every morning (if I remembered) I would snow shoe to the shed and use a long broom to take snow off. At one point in December though we got freezing rain, so I was not able to broom it right down to the glass for the rest of the year as it just made a crust.

This is basically as good as it got:



That is not regular snow but a more crusty ice/snow, so it's not physically removable without serious brute force, like on a car windshield, but I don't want to use that kind of force on panels.

How do you guys deal with this? I eventually want to live off grid so this is more or less a pilot project. My first thought is to change the incline of the panels so they are vertical, downside with a roof mount is that they will act as a sail and put a lot of stress on the roof when there are wind gusts. Another thought is to run thin wire behind them like a heated floor application and basically melt the ice away as needed, but this would require a much beefier battery. Ideally I should just need to melt the under layer and I should be able to get it off with the broom. In an off grid application and a much larger array I could replace the wire with pex tubing and glycol and run it through a boiler.

For general snow removal been toying with some kind of automated brush on a rail system that sweeps them hourly, maybe this would take care of freezing rain too by wiping them down? Downside is the bristles would get all icy after.

Anyway just curious what others have done to deal with this so that they can be used year round. I know it's also possible to backfeed power into the panels but I don't really want to mess with that. A mistake could be disastrous.
 
IF you know freezing rain is likely you could throw a rug or blanket over them during the storm or every night.

Not so helpful now though, sorry
 
I find that problem too. But so far this winter we've had enough warm spells that the snow and ice just slides off until the next time.
I thought about brushing, but it only works if you remember to do it!
I like your idea about the roof over them - especially in the winter when the sun is low and they're tilted around 45 degrees or so anyways (or whatever your latitude is) so the roof is not shadowing them.
 
I do not know anything about living in those kind of conditions but couldnt you spray them with the windshield washer stuff that has anti freze in it?
or some biodegradable antifreeze mixed with water. Just thinking out loud
 
I find with climate change we get way more weird weather patterns here now including freezing rain or wet snow. This ends up causing a crust on the panels which cannot be brushed off like regular snow. I have a 400w system on my shed which I just turn off completely in winter but it would be cool to run power to the house and run it year round. Last year I sorta had it running year round to keep the battery topped up but no load. Every morning (if I remembered) I would snow shoe to the shed and use a long broom to take snow off. At one point in December though we got freezing rain, so I was not able to broom it right down to the glass for the rest of the year as it just made a crust.

This is basically as good as it got:



That is not regular snow but a more crusty ice/snow, so it's not physically removable without serious brute force, like on a car windshield, but I don't want to use that kind of force on panels.

How do you guys deal with this? I eventually want to live off grid so this is more or less a pilot project. My first thought is to change the incline of the panels so they are vertical, downside with a roof mount is that they will act as a sail and put a lot of stress on the roof when there are wind gusts. Another thought is to run thin wire behind them like a heated floor application and basically melt the ice away as needed, but this would require a much beefier battery. Ideally I should just need to melt the under layer and I should be able to get it off with the broom. In an off grid application and a much larger array I could replace the wire with pex tubing and glycol and run it through a boiler.

For general snow removal been toying with some kind of automated brush on a rail system that sweeps them hourly, maybe this would take care of freezing rain too by wiping them down? Downside is the bristles would get all icy after.

Anyway just curious what others have done to deal with this so that they can be used year round. I know it's also possible to backfeed power into the panels but I don't really want to mess with that. A mistake could be disastrous.

I won't try to sell this as a home game, your batteries have to be fairly closely matched with your panels,
But I bypass the charge controller blocking diodes and allow batteries to heat the panels and the crap will come off fairly easily.
The panels become a 'Load' and warm up, you only have to get above freezing to get a layer of water between panels & ice and the ice comes off fairly easily, sometimes just slides off if the angle is vertical enough.
 
Increasing the slope of the modules helps shed snow.

I usually don't remove snow. It usually melts off on it own. But occasionally I will sweep it off to speed up the melt. Here is how I do it.
Step one is remove the bulk of the snow with a push broom. The next step is to go over it with a straw/corn broom. The goal of this step is to remove all the snow (the white stuff) that reflects light. At that point, the sunlight passing through the remaining clear ice will heat the module enough to melt the ice pretty quickly. Then I brush off the slush.

Mars
 
Yeah I'm starting to lean towards changing the tilt angle and hope it helps, may just need to reinforce the mounts or build a wind guard so they don't get ripped off the roof by the wind. Right now it's at 30 degrees, I should try to do at least 45. It would also make it easier to see them. At the start of the winter there is not enough snow on the ground for me to see them so I'm working blind with the long broom until the snow is higher up. (I can only go back so far due to the fence). I have not seen actual direct sun light since around October so I would not count on it melting on it's own. Once we start to get to the -40's the sun does tend to come out though but it's too cold to melt anything.

Can't really put anything on top before freezing rain, physically it would be very hard to do, and freezing rain often comes without warning. Earlier in December there was even a day where it was like -15 and somehow it was raining. No idea how that's possible. Rain tends to come completely out of nowhere here. Though I've thought of putting plexi glass that way I could use vibration or just brute force to get the ice off without damaging the panels. The plexy could be mounted on big springs or shocks or something. Not sure where I would buy that though.

How much voltage would I send to the panels if I did want to try to backfeed? Ex: if it's a 24v nominal system how much do I send? The battery is actually 12v but I could look at building a boost converter. Though if I'm going to use heat I'm leaning towards putting wire or pads behind the panels as a separate system, that way I could heat one panel at a time, and it would immediately start to produce at least some power once the ice melts and I brush it off.

If I had more room on my property I would definitely want to do a ground mount system, and I would just put them vertical, it would solve a lot of these issues.
 
I won't try to sell this as a home game, your batteries have to be fairly closely matched with your panels,
But I bypass the charge controller blocking diodes and allow batteries to heat the panels and the crap will come off fairly easily.
The panels become a 'Load' and warm up, you only have to get above freezing to get a layer of water between panels & ice and the ice comes off fairly easily, sometimes just slides off if the angle is vertical enough.
Generally, how long does this take?
 
Generally, how long does this take?

Depends on how much snow with ice under it.
Ice lets light through, so as the panels work they will also heat.
Snow blocks light so they don't produce,
Snow frozen on ice blocks light, so I jump the blocking diodes and let the panels become the electrical Load, they warm up.
I give them about 10 while I drink hot coffee someplace warm, then go after them with the ice scraper or a lot of the time a stiff bristle shop broom takes the crap off since it's melted loose from the panels.

On the East/West pivot panels, post/pipe mounts, I wish I had made provision for flipping the panels up side down.
Seeing the freezing rain/slush/snow coming, just flip them up-side-down and back upright in the morning.
Now that I'm retired, I might just look into doing that...

I'm lazy like that, we have radiant floor heat and I installed some extra coils under the patio pavers, a couple valves by the front door.
I refuse to shove snow, and for $5 worth of propane the snow shovel & ice melt salt stays in the garage...
 
Depends on how much snow with ice under it.
Ice lets light through, so as the panels work they will also heat.
Snow blocks light so they don't produce,
Snow frozen on ice blocks light, so I jump the blocking diodes and let the panels become the electrical Load, they warm up.
I give them about 10 while I drink hot coffee someplace warm, then go after them with the ice scraper or a lot of the time a stiff bristle shop broom takes the crap off since it's melted loose from the panels.

On the East/West pivot panels, post/pipe mounts, I wish I had made provision for flipping the panels up side down.
Seeing the freezing rain/slush/snow coming, just flip them up-side-down and back upright in the morning.
Now that I'm retired, I might just look into doing that...

I'm lazy like that, we have radiant floor heat and I installed some extra coils under the patio pavers, a couple valves by the front door.
I refuse to shove snow, and for $5 worth of propane the snow shovel & ice melt salt stays in the garage...
What do you do with the propane, and shovel? Rocksalt sounds like a good thing to throw on top after the snow is brushed off? Congratulations on your Retirement!!!! :) any plans besides upgrading your solar arrangement?
 
What do you do with the propane, and shovel? Rocksalt sounds like a good thing to throw on top after the snow is brushed off? Congratulations on your Retirement!!!! :) any plans besides upgrading your solar arrangement?

Radiant Floor Heat, Hot 'Water' (or anti-freeze) in tubes under the floor.
I just extended mine under the patio, with a couple of manual valves behind the front door.
I see snow, I turn on valves and go back to bed.
I wake up the snow is gone and I turn the valves off.

The snow shovel, ice melt stuff all stays buried in the garage where it belongs, not breaking my back...
$5 worth of extra propane to melt ice/snow off beats 3 hours on a snow shovel every time!

Same with meting off panels with battery bank, a few watts beats sweeping and scraping for hours in -5*F weather.
I jump the charge controller with a circuit breaker in the jumper and let the panels melt off ice/snow with battery power.
Once you get a few charging, they will supply power to melt off the rest...

I loose production until they melt off, but I'm not out there with a broom and ice scraper! I consider that a 'BIG WIN' for ME.
I drink coffee and watch them work FOR ME, instead of me working for THEM.
 
Yeah I'm starting to lean towards changing the tilt angle and hope it helps, may just need to reinforce the mounts or build a wind guard so they don't get ripped off the roof by the wind. Right now it's at 30 degrees, I should try to do at least 45. It would also make it easier to see them. At the start of the winter there is not enough snow on the ground for me to see them so I'm working blind with the long broom until the snow is higher up. (I can only go back so far due to the fence). I have not seen actual direct sun light since around October so I would not count on it melting on it's own. Once we start to get to the -40's the sun does tend to come out though but it's too cold to melt anything.

Can't really put anything on top before freezing rain, physically it would be very hard to do, and freezing rain often comes without warning. Earlier in December there was even a day where it was like -15 and somehow it was raining. No idea how that's possible. Rain tends to come completely out of nowhere here. Though I've thought of putting plexi glass that way I could use vibration or just brute force to get the ice off without damaging the panels. The plexy could be mounted on big springs or shocks or something. Not sure where I would buy that though.

How much voltage would I send to the panels if I did want to try to backfeed? Ex: if it's a 24v nominal system how much do I send? The battery is actually 12v but I could look at building a boost converter. Though if I'm going to use heat I'm leaning towards putting wire or pads behind the panels as a separate system, that way I could heat one panel at a time, and it would immediately start to produce at least some power once the ice melts and I brush it off.

If I had more room on my property I would definitely want to do a ground mount system, and I would just put them vertical, it would solve a lot of these issues.
-40!

I haven't seen that kinda nasty weather since I lived in the black hills and I'm not going back!
 
We don't get it as often anymore mind you due to climate change. Back when I was in high school I remember -50's! Even -40's are rare now but we get them. Anything after -30 all feels the same to me either way. :p

As for production when there is snow, believe it or not they still produce a little bit. Like if I skim off the fresh snow and it's only the crusty layer there's enough light that I produce around 5w or so. Hardly enough to keep up with just the inverter idle draw though. I turn it off and this year I even brought the battery inside.
 
Anybody who hasn't experienced sub zero F temps just can't be explained to... that's before windchill rain on top of that and forget about it ice pellets, snow powder...
 
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