heating solar panels????wt*......

daromer

Moderator
Staff member
Joined
Oct 8, 2016
Messages
5,468
Yeah unfortunately thats most likely the most common way. I could think of using heated elements under with water but then isolate the elements. Then you can use the heat during summer to heat water. But once again you then should/need to leverage the angle so the snow glides off. . Or thinner layers :)

I did some serious look at heating water under/cooling the elements but at same time then i would have needed more costly devices. So i bought a broom instead :D
 

Tarsun

New member
Joined
Oct 12, 2020
Messages
22
well fine then... lol
rock-salt, toss a few hand fulls up there.

im kidding, dont do that.

Sounds like removal is the most assured way to do it.

My thought was that you can have the "defroster" on low when it starts snowing and prevent build up. I know the shadows would be an issue but i also thought (in my very limited experience with PV's) that there were some small areas that weren't "active".
 

vegburner

New member
Joined
Mar 24, 2020
Messages
10
we just went through 2 more snow/melt cycles and I did not use any removal, but I do think i have an area of improvement. I have an ice dam effect happening at the bottom of each of the long vertical runs of panels. If there was a way to slick that shingle area so the lower panel snow slides once it hits the roof shingles, giving room for the upper panels to slide off, my panels would clear faster. Maybe some gutter heater wire to melt the buildup, but not sure its needed for the gains.
 

prepared1

Member
Joined
Jan 17, 2021
Messages
30
we just went through 2 more snow/melt cycles and I did not use any removal, but I do think i have an area of improvement. I have an ice dam effect happening at the bottom of each of the long vertical runs of panels. If there was a way to slick that shingle area so the lower panel snow slides once it hits the roof shingles, giving room for the upper panels to slide off, my panels would clear faster. Maybe some gutter heater wire to melt the buildup, but not sure its needed for the gains.
This discussion about snow is part and parcel of the argument people make who support the concept of tilt/adjust mechanisms. And, I suppose, an argument in favor of ground mount systems. Easier to grab a broom and brush the snow off if it isn't on your roof. And no roof leaks......

I recall seeing a solar hot water system that had an RV sunshade mounted at the top so they could cover the panels prior to a storm coming in. But then you have to get the snow off the shade before the panels can work. People also use them to prevent stagnation of the panel when they don't need production from it. (hot water)

I vote for the broom.
 

ajw22

Well-known member
Joined
Nov 16, 2018
Messages
531
Many people who live up in the mountains have a water pipe mounted along the crest of the roof. The pipe has small holes every 30 cm or so, and they use that to spray semi-warm well water (10~15C year round) onto the roof to melt/flush the snow. Requires much less energy than a electric heating system.
Unfortunately useless to clear solar panels around here, because the sun simply does not shine anyway.
 

jdeadman

Well-known member
Joined
Mar 28, 2017
Messages
929
Kinda Similar to deicing fluid on planes. Even like a car windshield sprayer just enough to help start the melting.
 

prepared1

Member
Joined
Jan 17, 2021
Messages
30
Many people who live up in the mountains have a water pipe mounted along the crest of the roof. The pipe has small holes every 30 cm or so, and they use that to spray semi-warm well water (10~15C year round) onto the roof to melt/flush the snow. Requires much less energy than a electric heating system.
Unfortunately useless to clear solar panels around here, because the sun simply does not shine anyway.
That is an interesting concept; worth looking into. THX.
 

OffGridInTheCity

Well-known member
Joined
Dec 15, 2018
Messages
1,355
>water pipe mounted along the crest of the roof.
Do you know how they keep the water from freezing in the pipes?
 

prepared1

Member
Joined
Jan 17, 2021
Messages
30
I don't know. If it is a drainback system, and only pressurized when needed, it might stay open. Would have to see how this is implemented.
 

ajw22

Well-known member
Joined
Nov 16, 2018
Messages
531
>water pipe mounted along the crest of the roof.
Do you know how they keep the water from freezing in the pipes?
Won't freeze as long as the warm well water is flowing.
I guess they have valves to drain it when not in use. Some well pumps come with a small heating system to keep it above freezing.
 

floydR

Active member
Joined
Aug 23, 2017
Messages
847
Constantly circulating water/anti freeze ( non toxic alcohol based anit-freeze) with solenoid operated valves might work.
Later floyd
 

floydR

Active member
Joined
Aug 23, 2017
Messages
847
NOT automobile anti-freeze, rather just enough alcohol (Glycerol)/(Ethanol) to lower the freezing point of the water. so it would be less likely to freeze inside the pipes.
Later floyd
 

Korishan

Moderator
Staff member
Joined
Jan 7, 2017
Messages
6,352
>water pipe mounted along the crest of the roof.
Do you know how they keep the water from freezing in the pipes?
I would imagine that while the pump is active, the drain solenoid is closed. Then when the pump is turned off, the solenoid opens and the water drains out of the system. No water in the pipes = no freezing.

And as far as Floyd mentions antifreeze, I think he means to have pipes in contact with the panels and flow the antifreeze that has been warmed up a little above freezing. This would heat the panels up enough to melt the ice.
Altho, I don't think this method would work over all, plus there's the expensive of the antifreeze and piping, and installation. Whereas a sprinkler system would be easy to install, no fluids to deal with (other than running water), and some basic electrical work and a switch.
 

floydR

Active member
Joined
Aug 23, 2017
Messages
847
Kinda Similar to deicing fluid on planes. Even like a car windshield sprayer just enough to help start the melting.
This is what I meant by anti-freeze circulating a closed system with a pump maybe with switch activated sprayers so you could control which panels got the spray. Drain back valves on a timer.You don't want to be spraying an already clear of snow panel. Non toxic because you live there. :)

later floyd
 

ajw22

Well-known member
Joined
Nov 16, 2018
Messages
531
Drain back valves on a timer.You don't want to be spraying an already clear of snow panel.

Could be easily optimized using a temperature sensor in the pipe (prevent freezing), light sensor wedged between the PV panels (detect snow), and another sheltered light sensor to detect sunlight.
 

prepared1

Member
Joined
Jan 17, 2021
Messages
30
I have solar hot water panels, and understand piping, pumping, tempering, etc well, and do all my own work. This is not an easy implementation. I'm not saying it couldn't work, but there are a lot of things that could go wrong.

If panels were mounted on my house, and water dribbled or lightly sprayed down the panels, it would flow to the lowest point and then create an ice dam when it refroze on the edge of the roof where we already have problems.

It would be much easier to do something like this on a ground mount. Another technology that might be easier to implement would be an air lance. Blow the snow off with compressed air.
 

ajw22

Well-known member
Joined
Nov 16, 2018
Messages
531
If panels were mounted on my house, and water dribbled or lightly sprayed down the panels, it would flow to the lowest point and then create an ice dam when it refroze on the edge of the roof where we already have problems.

These are systems in actual use in many towns around my place. Not just on the roofs, but also on driveways, parking lots, and even the roads. They don't dribble... I'd say it's about the flow of the windshield washer jets on cars, from each of the dozens of holes in the pipe.

Of course, there will be a point where the ambient air temperature becomes too low and the water will start to freeze before reaching the drain... have yet to witness that though.
For the roads, they have to be careful when to turn it off the flow of warm well water... could lead to a very slippery iced up surface.
 

Eric44

New member
Joined
Jan 30, 2020
Messages
21
Only water in panels with drainback system, no problems in winter, see Heliofrance or Rotex.
 
Top