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

100kwh-hunter

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I was on a other forum with solar panels and someone(like all of us sooner or later) had snow on his pv.
So no energy, they suggested to add one and keep it clean: one panel at ground level and redirect the harvest to the other panels to desnow/deice them?!?!?!?
My suggestion was to put some thin resistance wire on the pv just enough to let the snow and ice melt, but oke...redirect the energy to heat up the other panels to clear them from snow/ice???
Can someone explain to me please?

Thanks in advance, Igor
 

hbpowerwall

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Often wondered why there wasn't a commercial product that did this.
 

not2bme

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They say if you hook up a panel directly to a battery (without a charge controller) that at night the panel will start to consume power if you don't have a blocking diode. The cells are capable of generating a little heat as a result of the consumption. I'm not sure if the bypass diodes on most panels nowadays will allow that or maybe it will still work?
 

Cheap 4-life

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100kwh-hunter, I’d suppose the one panel would produce power. That power would flow thru the snow covered panels. That power flow would slightly heat the snow covered panels.
 

hbpowerwall

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I've never seen snow but what about just dead shorting the panels? Surly some watts would be produced & wouldn't take much to melt first mm of snow and allow for snow to slide off?
 

daromer

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There are commercial products here but do note that during winter the panels produce the best at high angle. If the panels are just slightly open they will heat them self and the snow will fell off.
You can heat them by pushing in energy into them and you can have heating element.

With that said where i live i have had 2-3 days at most during the winter where i wished i had that type of function but dont forget that heating 1dm of snow takes ALOT of energy so if you dont have proper angle on them so the snow can glide off the energy needed is greater than you ever produce that day!!

If i got dead nice days and this only happens during spring i run up on the roof and just touching them with the brush and the snow glides off. This takes me max 5 min. And take into account all my panels i would not save up the investment heating them compare to the gain. This is for where i live.

Also note that when you got alot of snow you might not have much valuable sun.
 

vegburner

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That is super interesting that they can heat themselves. Does this hurt them in any way, and how much juice we talking to heat 13kw worth of panels?

We get 300 days of sun here a year, but we also get hammered with good snow storms. I look at the 3 day look ahead after a snow storm and if its going to be overcast for a few days i leave the snow up there. If its going to be sunny the following day, i use a 20' roof rake shovel with 3 extra extensions to get to the bottom half of my panels. In comparison to my neighbor's panels, i will get 3 to 4 more days of sun as compared to hers. The top panels slough off quicker with the bottom half baking in the sun.

I'd be more interested in a cleaning system as we can go a month without a rain event and the panels seem to get covered with grime and if i had to put a non-scientific guess on what it loses in my system might be 5% kwh less produced for the day. My roof is steep and cleaning them is a pain, I have to be tied off.
 

completelycharged

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+1 to the use a brush if your desprate for power.
If it's snowing your electricity will be a big premium....
Trying to heat panels with an inch of snow on them in -3C will never work economically
Work out the latent heat requirement just to melt the snow... then factor in radiant losses battling sub zero..

This is what it can be like as this was my roof....

Cant figure out how to add the existing image from previous post (using BB code fails ?)
View attachment 17063
 

vegburner

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Love your graphical representation, if that doesn't show it could be worth it.

We call it the Solar Shovel here. If the sun can do the work for you, let it. BUT if i can make my own power earlier and more of it with a little bit of work, i will. I can make 70kwh+/day for 3 or 4 days while my neighbors panels just sit covered. I am sure they look over at me and shakes head....while i look over at their panels and shake my own head...
 

daromer

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As i said you often dont have alot of sun in the winter. As an example i get 5% of the total solar in average during winter comparing to summer. (yes i live north)
A very very good day i can get 15% compare to summer but we dont get that many of those but if i know we will have a couple of hours good weather i go out and touch the panels with a brush so they start to self heat up and then the snow just falls off basically.
For me its not even worth considering heating the panels. The only thing if so is sprinkling hot water on them but that could be dangerous too if it freezes to ice instead.
 

vegburner

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That's tough. We got 3 inches of snow last night and its 11am and my panels are almost clear from the sun. We have such different weather, my best days are in the winter Feb/Mar with the longer days and less cloud cover. The long summer days are blocked in the afternoon by monsoonal flows of rain and cloudcover. I found a guy on YT with my exact same sized system but installed in Boston as opposed to Colorado and his yearly output was half of mine with the exact same system size/panels/inverters/etc.

I consider myself lucky to a certain point.
 

hbpowerwall

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Ok so weird idea - small vibration motor under mounts of panels or on mounts? Look idea has some issues but its still an idea
 

Korishan

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Ok so weird idea - small vibration motor under mounts of panels or on mounts? Look idea has some issues but its still an idea
This would work if the panels were on small springs. Being that they are firmly attached to a metal frame that is then attached firmly to a roof (usually), a vibrating motor would need to work really hard (in other words, a lot of vibration) and would make a lot of noise when they run. Imagine a heard of horses galloping across your roof :p
If the panels were on springs of some sort, so they floated slightly, then the motor idea would work.
 

Hyraelle

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Oh, well, my idea for the future ( I have not yet started the process of learning how to assemble them, yet. ) Would be to leave them almost upright. My plan in my head is a frame that i can change the angle, 70 degree almost upright in the winter, and about 30 degree horizontal for the summer.
This way, both the snow would not stick, and the sun will be angled closer to the main seasons.
 

Korishan

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Yeah, that's great for ground mounted systems. there are a lot who do this, especially more equatorial regions where the sun goes from being south of the panels to north of them (here in central Florida then sun will actually cast a shadow facing south for couple weeks)
 

daromer

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The angle is the key here. Vibration will not work. The snow will ice on the panels depending on when the snow comes in and thats the worst problem.

Having them in an angle as i said from the beginning will make the snow just run off quite fast when there is just slightest sun on them. The panels are dark and heats up very quickly.
 

Tarsun

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i dont have much experience with panels so take my idea with a grain of salt.

i do know that you can buy heat paint (the stuff used on the windshield of your car). Maybe you can make a few thin traces with the paint between the cells or grid of cells and then just power that.... ?
maybe have a spare car battery on hand to use it when you need to melt the snow.
 

daromer

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They cant supply enough heat to get rid of 10cm of snow. They are used to keep fog away from a windscreen and nothing else :)

As said before we take a HUGE amount of energy to melt the snow if you want to get rid of it. Best is just to brush of the snow and let the sun heat it up. The sun can supply more heat than you make and then heat with ;)
 

Korishan

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Not to mention the paint would cause a shadow on all the cells in a row. any shadow will have noticeable effects on power production
 

Hyraelle

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In my experience, it could work, after some time there would be a layer of water just enough to let the caked in snow/ice to slide, but even for cars it's lazy and we still need to do the other windows. So we start the car, take the brush/scraper tool and go at it :)

Daro gets it. There isen't much ways around removing the snow and letting the sun do its job :)
 
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