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

[Red Squirrel]

For dust couldn't one use compressed air to blow it off? Brush would work too, except it might scratch panels over time, but think compressed air or even leaf blower with long ABS pipe could work. At least it does not stick like the wet snow or freezing rain does.

Could you place some rigid sheeting on the sides and back at an angle to act as a wind deflector? So rather than the wind getting under the back of the panel, it's directed up and over? Kinda like a wind deflector on the front of a van or lorry?

Could be made out of plywood or some thin metal sheeting?

Thought of that too just need it to not look obnoxious in case someone complains. My city always sides on complainers when it comes to "eye sores". But yeah I could probably use plywood and paint it or something. Will need to look into it this summer when I redesign the mount to allow a tilt. I could get fancy and make the tilt movable, or just make it static. Static is probably going to be easier to make sure it's strong.

 

[Steve_S]

For dust couldn't one use compressed air to blow it off? Brush would work too, except it might scratch panels over time, but think compressed air or even leaf blower with long ABS pipe could work. At least it does not stick like the wet snow or freezing rain does.

Thought of that too just need it to not look obnoxious in case someone complains. My city always sides on complainers when it comes to "eye sores". But yeah I could probably use plywood and paint it or something. Will need to look into it this summer when I redesign the mount to allow a tilt. I could get fancy and make the tilt movable, or just make it static. Static is probably going to be easier to make sure it's strong.

Compressed Air is used on solar field in deserts, no brushes .

BTW, covering the back of the panels is not wise, panels heat up FAST and need air to cool them, also condensation should not be allowed to build up on the backsides, tat can cause other issues.

 

[Red Squirrel]

Can the heat damage the panels or does it just cut into efficiency? I can deal with an efficiency loss for 2 months of the year when I'm generating way more power anyway. But I don't want to damage them either...

 

[ghostwriter66]

Can the heat damage the panels or does it just cut into efficiency? I can deal with an efficiency loss for 2 months of the year when I'm generating way more power anyway. But I don't want to damage them either...

I don't see how the heat could damage them --- here in south Texas they get so hot you can literally cook on them ... the efficiency plummets but I have not seen any "damage" ... but interesting question ...

 

[Sgt Raven]

Reading suggestions I thought there are some modern coating they apply to car windows that make them super slick. Then I remembered most of them have a UV inhibitor in them and thought that's probably something you wouldn't want on a solar panel..

 

[CrapshootIdeas]

Hey so, I've been looking for a solution to this for a couple days now so I can continue my feasibility study and possibly build a very large system of used panels. I live in Iowa, and we get nasty, nasty winters. Snow buildup for weeks or months, and the house I'm moving to is too tall to manually clear snow. I've been messing around with a few snow clearing ideas based on several different repurposed technologies, but the one that just seems to make the most sense is using heated cable that's mounted to the back of the panels. Plug it in when you need to melt ice, keep them on until the water runs off (no refreeze) and done. They also wouldn't drastically restrict heat rejection on the back of the panels during hotter seasons because the surface area is extremely low.

I did a search on this thread and didn't see mention of the word cable, so forgive me if others have brought this up.

Here's an image of what I'm talking about:

 

[Supervstech]

Hey so, I've been looking for a solution to this for a couple days now so I can continue my feasibility study and possibly build a very large system of used panels. I live in Iowa, and we get nasty, nasty winters. Snow buildup for weeks or months, and the house I'm moving to is too tall to manually clear snow. I've been messing around with a few snow clearing ideas based on several different repurposed technologies, but the one that just seems to make the most sense is using heated cable that's mounted to the back of the panels. Plug it in when you need to melt ice, keep them on until the water runs off (no refreeze) and done. They also wouldn't drastically restrict heat rejection on the back of the panels during hotter seasons because the surface area is extremely low.

I did a search on this thread and didn't see mention of the word cable, so forgive me if others have brought this up.

Here's an image of what I'm talking about:
View attachment 16188

I think the issue with this is the focused temp they attain.

The vinyl backing, or even the cell itself could be damaged...

 

[ghostwriter66]

Hey so, I've been looking for a solution to this for a couple days now so I can continue my feasibility study and possibly build a very large system of used panels. I live in Iowa, and we get nasty, nasty winters. Snow buildup for weeks or months, and the house I'm moving to is too tall to manually clear snow. I've been messing around with a few snow clearing ideas based on several different repurposed technologies, but the one that just seems to make the most sense is using heated cable that's mounted to the back of the panels. Plug it in when you need to melt ice, keep them on until the water runs off (no refreeze) and done. They also wouldn't drastically restrict heat rejection on the back of the panels during hotter seasons because the surface area is extremely low.

I did a search on this thread and didn't see mention of the word cable, so forgive me if others have brought this up.

Here's an image of what I'm talking about:
View attachment 16188

Here in South Texas the only time we see white stuff like that is when the Border Patrol stop by and shows us a large drug seizure they have done ...

 

[Red Squirrel]

That's sorta the idea I have in mind, but use telecom wire (I have lot of it, and it's decently thin) and then passing current through it so it warms up. It would be sandwitched with foam to force the heat to go through the panel and not just radiate out the back or get removed by the wind.

Downside of that is the panels might overheat in the hot season with that foam. We can get very hot days in summer now, like I've seen it go into the 30C range sustained for a few days. So I do wonder just how hot the panels would end up getting and if it would be dangerous for them. They CAN catch on fire, it happens. Even Tesla had lot of issues with fires at Walmarts way down south. In their case I think it had to do with panels being horizontally mounted, so they could not shed heat easily.

What I might end up doing though is doing the wire without the insulation at first, just to see how well that works out. If I have time this summer I want to redo the panels a bit too, tilt them at a greater angle, and also make sure they clear the edge of the roof, that way if snow does slide off it will fall on the ground instead of on the roof and accumulate.

Each panel would be on a separate constant wattage power supply and there would be a temp sensor, so I would basically drive the voltage on the wire to the point that the temp sensor starts to read in the positives. I guess basically it would be a current limited constant temperature power supply.

I still need to experiment a lot with the electronics side of that before I feel comfortable with it though.

 

[CrapshootIdeas]

That's sorta the idea I have in mind, but use telecom wire (I have lot of it, and it's decently thin) and then passing current through it so it warms up. It would be sandwitched with foam to force the heat to go through the panel and not just radiate out the back or get removed by the wind.

Downside of that is the panels might overheat in the hot season with that foam. We can get very hot days in summer now, like I've seen it go into the 30C range sustained for a few days. So I do wonder just how hot the panels would end up getting and if it would be dangerous for them. They CAN catch on fire, it happens. Even Tesla had lot of issues with fires at Walmarts way down south. In their case I think it had to do with panels being horizontally mounted, so they could not shed heat easily.

What I might end up doing though is doing the wire without the insulation at first, just to see how well that works out. If I have time this summer I want to redo the panels a bit too, tilt them at a greater angle, and also make sure they clear the edge of the roof, that way if snow does slide off it will fall on the ground instead of on the roof and accumulate.

Each panel would be on a separate constant wattage power supply and there would be a temp sensor, so I would basically drive the voltage on the wire to the point that the temp sensor starts to read in the positives. I guess basically it would be a current limited constant temperature power supply.

I still need to experiment a lot with the electronics side of that before I feel comfortable with it though.

Yeah I would be real careful about putting uninsulated, resistive wire in an airflow restricted space that's attached to your house - especially if your solar panel frames are grounded.

I'm an electrical engineer and could potentially help with your control scheme. My two concerns with having a constant supply (the panels) is that A) you will always be consuming power, even when there is no snow and B) if the panels are covered in snow, they can't provide power to melt the ice. If the assumption is that the panels will never get cold enough to have snow on them, defer to concern A. I've been toying with what I'd consider a robust temp control system, but honestly, working off batteries strongly suggests that a second inverter just for the heaters would be required. The more direct solution is to use grid tied power to operate the heaters with a simple manual switch inside on a timed device, like what you often find on the side of public hot tubs. I think this is my approach for the time being.

 

[CrapshootIdeas]

I think the issue with this is the focused temp they attain.

The vinyl backing, or even the cell itself could be damaged...

Actually, that's a blessing in disguise. I was struggling to figure out how to have the heated cable laying on a bare solar rack on my roof, lay the panel down and then somehow apply the glued cable to the rear. I think it seriously simplified the assembly and service if I'm able to build a sort of baffle system for the panels to lay on top of. Doing so would do three things: A) such a baffle system would still allow for airflow during warm weather, but would not actually be fully open so it would give a sort of enclosure effect during snow build up and provide an easy structural surface to mount/lay the cable before installing the panels B) doesn't require me to apply loads of adhesive to the back of my lovely panels C) provides radiant heat to the whole panel surface via the enclosed box effect provided by that pesky snow, so the panel should clear more evenly. I really like where this idea is headed! I'm going to take a 12v battery and panel and build a little mock up sample for testing at ground level this summer!

 

[FilterGuy]

If you go back to the first page of this thread, @JeepHammer had a very interesting scheme that he says works for him. He bypasses the charge controller and the blocking diodes and lets the battery send reverse current through the panels to heat them up (there are more details in the post). I have not had a need for this but if I did I would seriously consider it.

 

[RCinFLA]

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 thought that's what remote car starting with defroster and heater on was for! A guy from Chicago told me that.

 

[Red Squirrel]

Yeah I would be real careful about putting uninsulated, resistive wire in an airflow restricted space that's attached to your house - especially if your solar panel frames are grounded.

I'm an electrical engineer and could potentially help with your control scheme. My two concerns with having a constant supply (the panels) is that A) you will always be consuming power, even when there is no snow and B) if the panels are covered in snow, they can't provide power to melt the ice. If the assumption is that the panels will never get cold enough to have snow on them, defer to concern A. I've been toying with what I'd consider a robust temp control system, but honestly, working off batteries strongly suggests that a second inverter just for the heaters would be required. The more direct solution is to use grid tied power to operate the heaters with a simple manual switch inside on a timed device, like what you often find on the side of public hot tubs. I think this is my approach for the time being.

Oh it would not be on all the time, that would draw too much power. It would be manually activated only when a crust forms. For normal snow, mechanical removal is better (for now, manually only). Eventually I want to add a web cam so I can see the panels. Also I would only do one panel at a time since I would probably drain the battery so at least that panel would produce so I can do the other panels the next day. The wire would be insulated, it's basically kinda like individual wire inside cat6, but a bit thicker. I probably would run it off either a separate inverter or just a step up converter. As much as I don't want to put active electronics outside of the shed I think for this particular case it makes more sense to send the power as higher voltage direct to the point it's needed, then the converter would step it down to a few volts, or whatever gets the wire hot enough. This would basically be a dead short so I don't anticipate needing to put much voltage through it in order to get it hot. Another approach is to just send battery voltage up as it would probably be high enough on it's own. Need beefier cabling for that though, especially because I'm creating a dead short.

 

[Wits' End]

Average closer to 'warm' Lake
I have had my panels up for about 1.5 years. About July got everything done. I live in NE Minnesota, on the northshore of Lake Superior, two miles inland. As Supervstech said, 'real snow' and 'real cold' have to be lived to believe/understand.

My panels are 1.5 stories up, last year we did pull a foot of snow off, a few times. Not fun. I've never dealt with "heat tape". I'm planning on running our generator to power it, to help get rid of some stripes of snow, hoping the rest will slide. I have two arrays, 6 & 12 panels, about 10 & 20 feet wide, 4 foot gap, ~12 feet tall. Is the best way to attach the 'tape', using panel clips on the panel frames, then under the panel over the U-Struts, so it hangs close, but under the back surface? Otherwise - suggestions, specifically about attaching 'heat wire/tape' to de-ice/snow solar panels. Thanks

 

[FilterGuy]

A couple of years ago one guy on the forum talked about running current backward through the pannels to warm them up. My first reaction was "That is crazy", but the more I thought about it the more I realized it might work as long as the reverse current never exceeded Isc. I have never tried it but he claimed he could clear ice and snow quickly.

 

[Supervstech]

A couple of years ago one guy on the forum talked about running current backward through the pannels to warm them up. My first reaction was "That is crazy", but the more I thought about it the more I realized it might work as long as the reverse current never exceeded Isc. I have never tried it but he claimed he could clear ice and snow quickly.

Snow on my panels is killing me

OP here. Guys I apologize that I have been absent from this thread for so long. Things have changed for us. On June 15th, 2021 we had a massive forest fire that completely burned our 40 acres and the entire area. All the trees are gone ? (Robertson Draw fire outside Red Lodge, MT). Our...

diysolarforum.com

 

[Wits' End]

I've read about back feeding panels. Interesting but not something I want to risk ?. I'm really looking for any information on the best way to set heat tape up, for most efficient mounting and heat transfer.
Thanks!

 

[gotbeans]

A couple of years ago one guy on the forum talked about running current backward through the pannels to warm them up. My first reaction was "That is crazy", but the more I thought about it the more I realized it might work as long as the reverse current never exceeded Isc. I have never tried it but he claimed he could clear ice and snow quickly.

pretty genius idea if it works well.
@JeepHammer is this method still working well?

 

[rcguymike]

Been reading this thread the last couple days here and there and noticed that my panels did exactly what was described here. The bottom 2 110's are series together, but then the middle 2 are in parallel together and then in series with the top 220. Top 3 group in parallel with bottom 2 group. Those seem to have heated the bottom 2 panels, a happy little accident in design, since the bottom panels are most likely to have water and ice shed onto them from the top panels

New item by Micah Kuiper

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