Back feed for snow melting?

[curiouscarbon]

 

[Supervstech]

Why in the hell would he pour boiling water on a freshly cleaned of snow or ice window? Just to dramatically show glass will crack?

 

[Hedges]

I have also heard a sunbaked hot window can shatter from cold water use...

No experience with that one...
I did live in Tucson for a year though... just never washed the car.

It works for car windshields (don't ask me how I know.)

 

[curiouscarbon]

Why in the hell would he pour boiling water on a freshly cleaned of snow or ice window? Just to dramatically show glass will crack?

welcome to garage 54 ???️?

to stay on topic, electromagnets could theoretically be switched repeatedly and induce current in the solar panel to create heat for melt snow. please do not do this, because in theory it is very inefficient

 

[Hedges]

Perhaps this process, but at < 5kW RF power

Induction de-bonding of a silicon wafer from the surface of a steel part

Heating with induction of silicon wafer and process to de-bonding it from the flat surface of a cylindrical piece of steel.

ultraflexpower.com

 

[WattAboutThat]

Idea 01
I am very new but I have a few ideas that might work, having said that I do not have any experience, so use caution if try, please advise of any of these ideas work:

Idea 01:

Install a heating pad on the back of each panel, they probably make larger ones for some industry, say for farms etc.

Then connect them to an independent power source that you can control on and off.

If you want independent control get an X10 type remote controlled plug, that is addressable, and get one for each heating pad on each panel, so that you can specify which pad or pads to turn on as needed.

here is a youtube video of someone else experimenting with this concept:

Here is a potential product that is essentially a large heating pad, that could work for this
Idea 01, but it is too pricey. Maybe someone out there knows of a diy hearing pad design that we could create for a lot less cost per unit. It cant be that complicated ro create a pouch with a resistive heater, in a thermal gel to dispurse the heat evenly throughout the pad.

HeatTrak Heated Snow Melting Mats for Home | Heated Floor Mats

HeatTrak Snow Melting Mats melt snow on contact to prevent snow and ice accumulation on walkways and stairs around your home. Mats are portable, engineered to be left out all winter long and melt 2" of snow per hour. The Walkway Mat and Stair Mats can be used independently or connected to create...

heattrak.com

 

[OffGridForGood]

I'm interested to see if dual panels (PV and solar thermal hot water) would provide an easy side-benefit for snow and ice melting: ie running pre-heated water through the thermal pipe portion to apply heat to the PV for ice removal. This would limit cost of the set up since the piping/pump/tank would already be a part of the overall system, and many independent methods of water heating (ie fire wood) could be used to create heated water for the process in winter. Just need to see how the two systems are built into a panel, to ensure efficient heat transfer. Got me wondering.

 

[brum]

Here is a potential product that is essentially a large heating pad, that could work for this
Idea 01, but it is too pricey. Maybe someone out there knows of a diy hearing pad design that we could create for a lot less cost per unit.

Heating pads would imply that you will do work on the back of the panels. If so - I would go with self-regulating heating cables. There are 12VDC, 24VDC, 48VDC, 110AC and 230VAC versions. The power varies between 10W/m and 65W/m. These are cheap in Aliexpress.

 

[justgary]

Different materials have different emissivity. The IR camera measures the emitted IR radiation.

Let me give an example. The numbers are most likely wrong, but let's say that we have aluminum with an emissivity of 60% and the panel part covered with glass has an emissivity of 40% and both are at the same temperature. In that case, the IR camera will show the aluminum part hotter than the glass part.

Measure polished stainless steel cup with boiling water. Last time if I recall correctly the IR thermometer was showing ~40C. But touching it was impossible.

The general solution to varying emissivity is to stick a piece of black electrical tape on the object, then use the IR camera to measure the temperature of the tape.

 

[cs1234]

Thread necromancer here.

Would it be possible to "shake" the snow off the roof from the underside with some bass shakers or large subwoofers in the attic underneath the panels? Too risky for racking and roofing? Not powerful enough? Might work a treat on an A-frame.. maybe not so much on something with a lower tilt.

 

[OffGridForGood]

Maybe we can find out!
you try out the mega-bass method:

I got a "shaker" from a bakery we were updating a few months ago (they use the shaker to keep flour from clumping in a commercial bakery set up) since the new equipment included a new shaker, I got the old one for free and am planning to bolt it to the underside of my main PV array, on a switch, to see if it will vibrate the rack enough to get the snow to slide off. The shaker is actually 3-phase 208, but it seems to shake ok with single phase 240, so we will try it out this winter - and report back, and compare "notes"

 

[cs1234]

Maybe we can find out!
you try out the mega-bass method:

I wish I could help you in the experiment. Unfortunately, I live in Texas. It's not even a guarantee I'm going to get any snow. Ice, that knocks out power to my house for a week.. maybe. Beautiful snow, enough to frolic in or provide more than the barest of dustings.. not likely.

I'll cross my fingers for you though.

 

[OffGridForGood]

Are ya sure?

Unfortunately, I live in Texas. It's not even a guarantee I'm going to get any snow

I heard something about some snow in TX - was that in 2021?
(just joking with ya, hope there are no more of those events any time soon).
I literally tilt up my panels for snow removal - not solar angle gain. LOL. I am expecting the shaker to work, but like you say, freezing rain, that can be a tough one.

 

[Vigo]

I would expect the vibration to dislodge some snow, but i would be surprised if the snow made a 'clean break' and all slid off. I picture the accumulation of snow just getting shorter and shorter until you're at a low thickness, but then the shaker will stop producing any more benefit. That's my brain spitballing it, no science and no experience! Im curious to see what's real..

 

[cs1234]

I would expect the vibration to dislodge some snow, but i would be surprised if the snow made a 'clean break' and all slid off. I picture the accumulation of snow just getting shorter and shorter until you're at a low thickness, but then the shaker will stop producing any more benefit. That's my brain spitballing it, no science and no experience! Im curious to see what's real..

Maybe if you had a series of them, going down the roof. That way the whole thing vibrates all the way down.

 

[OffGridForGood]

Maybe if you had a series of them, going down the roof. That way the whole thing vibrates all the way down.

Not the roof, the tilt-up frame the PV is attached to above the roof.

I would expect the vibration to dislodge some snow, but i would be surprised if the snow made a 'clean break' and all slid off. I picture the accumulation of snow just getting shorter and shorter until you're at a low thickness, but then the shaker will stop producing any more benefit. That's my brain spitballing it, no science and no experience! Im curious to see what's real..

I tilt up the PV frame to 60-65 degrees for the winter.
Once we are in the 'real' winter - ie cold and just stays that way, the snow doesn't stick to the PV it just catches on the lip of the aluminum frames and builds behind that all the way up the panels.
Last year I used a shop push broom on a long extension handle to clear snow, just touching the snow and it slid right off, barely need to touch it and it all slides off cleanly.
The more difficult time of the year is November, when we can get cold nights and mild days, freezing rain during the day and then turn cold overnight to set that mess into solid rough ice stuck to the glass, that is not going to go anywhere with a shaker. Last year we had about 1" of freezing rain one day, turned cold overnight - froze solid and then snowed on top of the frozen layer about 3" of white fluffy stuff, I worried that was going to be there all winter! But a couple days later we got a warm sunny day and it all slid off. I think my bifacial panels at 65-degrees saved me actually, picked up just enough off the backs to warm up the glass and let the ice slide off. No way this would work at a low angle in my area.

 

[curiouscarbon]

interesting point about the back side of bifacial solar panel being darker and, in certain circumstances, reflected sunshine would provide more heating than with an all-white backing material

 

[byteharmony]

Last winter I used gorilla glue to test a few panels with the heated rope. Worked better than not having it.

This year I started with a larger test of 6 panels. Results?
1. Cable management was not fun. These panels were on an asphalt shingle roof so the panels also had rapid shutdown devices. Running 100 feet of heat wire around all those wires added a significant amount of time to install. Of course, we hope that time will pay back when we have power coming from the panels in the winter.
2. Varmints - When we took the test heated rope down we found critters had chewed into it. I've seen a video or two where this happens on roof systems. Anyway, the heat wire is up under all the panels using hayco clips, but the ac 120v cord still dangles like a carrot for the critters.

My roofing buddy says, traps traps traps. It's the only way.