Snow on my panels is killing me

[sunshine]

There is nothing on the south roof of the bouse because it's the off side for the sun

Just being pedantic by pointing out a curiosity- In Brisbane,27.4S, for the last few weeks the southern facing walls are first to greet the sun!

 

[MurphyGuy]

I live in Michigan, here is the only advice I can give you:

1) If part of the panel is clean, it will warm up a bit and melt the rest of the panel. When we get snow, I usually brush off the heavy stuff and let the sun do the rest for me. Once a small amount of black is showing, the sun's light heats the panel up a bit and melts the rest. The process is obviously dependent on how deep the snow is, but generally speaking, and inch of icy snow will be gone in two or three hours.

2) May I suggest some kind of pipe-heating cable be installed under the panels and in contact with the back-face? I've never actually tried this, but if you were to attach about 15 feet of that anti-freeze gutter or pipe heater cable to the underside of each panel, it would probably only take about 20 minutes for it to melt most of the ice away.

3) I bought a Makita 36v leaf blower and I now blow the loose snow off my panels. We normally use a push broom at the end of a 16 foot extension pole to pull the snow off the panels. But I discovered that sometimes the snow is that super light and fluffy type that just needs a good gust of wind.
The leaf blower takes me about 5 minutes to blow off my 14 x 56 foot array (ground mount). We bought a battery unit so we don't have issues starting a gas unit in the cold temps.

4) If the inside of that barn is heated, you could pipe some of that warm air to the underside of those panels. A small automotive style blower fan connected to some 2" pvc pipe would probably deliver enough warm air to melt the snow and ice away. Some skirting on the outside edge of the panels to keep the warm air constrained a bit might also help.

5) Move the entire array to the ground and put it on a single axis tracking system. Your array is small and could easily be supported by a couple of 6 x 6 pressure treated lumber posts. Tilt it vertical when it snows. This would also increase your power generation from season to season since the array would no longer be slaved to the angle of the roof.

 

[rhino]

A note about expecting the sun to melt snow off.. depending on where you live and the ambient air temperature the black framed panels work much better for fully getting snow and ice off. I have both black framed and silver framed panels on same array and the silver framed ones has ice that forms from the snow melting off the actual panel surface. The black frames ones warm up enough in the sun to prevent the melt water from refreezing on them.

 

[100kwh-hunter]

@MurphyGuy I like your number two, simple jet effective...

Thinking out loud:
But some resistance wire we use to prevent freezing up the water pipes below campers?
Nickel something wire? i hope someone can fill this in.

Its very thin wire 1 or 2 mm and can be hot glued to the panels surface between the cells.
It works for defreezing water pipes why not make a grid on the panel it self?
Just a thought.
My two cents
With best regards Igor

 

[rhino]

Thinking out loud:
But some resistance wire we use to prevent freezing up the water pipes below campers?
Nickel something wire? i hope someone can fill this in.

Its very thin wire 1 or 2 mm and can be hot glued to the panels surface between the cells.

You are thinking of nichrome wire.

 

[45North]

Could you spray them with automotive windshield washer?
Good to -40.

 

[100kwh-hunter]

Could you spray them with automotive windshield washer?
Good to -40.

Add some wipers also...sorry could not resist, forgive me.
Oke...
I think that would be a solution but it will give you a other problem...put it on your front car window or the windows in your house, you will see what i mean.
Best Igor

 

[MurphyGuy]

@MurphyGuy I like your number two, simple jet effective...

Thinking out loud:
But some resistance wire we use to prevent freezing up the water pipes below campers?
Nickel something wire? i hope someone can fill this in.

Its very thin wire 1 or 2 mm and can be hot glued to the panels surface between the cells.
It works for defreezing water pipes why not make a grid on the panel it self?
Just a thought.
My two cents
With best regards Igor

I would say that nichrome would probably work but you better make sure you go gentle with it. If it gets too hot, it will damage the panel. I would also worry about thermal shock at high temps. And hot glue will eventually just fall off. You'll need to use something like Permatex.

I was actually thinking of something more in line with Carbon Fiber tape. Carbon fiber tape is actually a woven cloth. Comes in various widths from 1/2 inch to 2 inches or more. Search for diy carbon fiber heaters on youtube and you'll see people playing with it. I have a pair of socks I made by sewing the tape into the toes to keep my Michigan feet warm when hunting. I just plug in an 18650 pack to it.

You could try the nichrome wire, just make sure it doesn't get hotter than about 80 degrees. You're not trying to cook the panels, just warm them slightly above freezing so the sun can start working.

 

[digit]

@MurphyGuy I like your number two, simple jet effective...

Thinking out loud:
But some resistance wire we use to prevent freezing up the water pipes below campers?
Nickel something wire? i hope someone can fill this in.

Its very thin wire 1 or 2 mm and can be hot glued to the panels surface between the cells.
It works for defreezing water pipes why not make a grid on the panel it self?
Just a thought.
My two cents
With best regards Igor

Amazon.com

no reason these wouldnt work.
already thermostat regulated.
depending on the scc you could have them disconnect when the panels start producing power.

 

[Savern]

You could adapt this to a pressure tank to apply de-icing fluid!

24' Telescoping Wand

Would RV antifreeze work as a de-icer?

 

[100kwh-hunter]

You could adapt this to a pressure tank to apply de-icing fluid!

24' Telescoping Wand

Would RV antifreeze work as a de-icer?

Why a pressure tank? go to a car scrap yard and you will find all the parts needed, incl tank electronic pumps hoses and nozzles even a good lead acid cell if wanted/needed...sorry did not mean to be rude

 

[hammick]

OP here. We were doing fine until about two weeks ago. I've been remotely staring my generator for over 10 days to keep the batteries above 60%. I spent all my time during the 45 days were were up over XMAS installing my LifePO4 bank. Didn't have time to address my panel/snow problem. Yesterday my neighbor spend about 2 hours in -17 degree weather clearing my panels. She got five of them partially cleared. Yesterday I was getting 4 -5 amps of charging and was happy. Well the wind covered them overnight and I'm not going to have her do any more clearing. I'll ask her to switch out my aux diesel tank so I can keep charging with the Genset.

So I have to get this figured out and will head up in March to install some South facing panels.

When we aren't there I can get by with between 7 - 10 charging amps for now. What size panels do I need to get that assuming they are completely vertical?

Or if I am willing to spend hundreds more could I install two of these Panasonic 340w panels in parallel to get approx 9 amps of charging?

Panasonic 340W Solar Panel 96 cell VBHN340SA17 Monocrystalline White - A1 Solar Store

Panasonic 340W VBHN340SA17 Solar Panel 96-cell combines great aesthetics and efficiency with proven reliability | Reviews, pictures - A1 Solar Store

a1solarstore.com

Can I skip using a combiner box for now and just put the sting on a breaker in my Midnight Solar box. The combiner box for my roof panels is not at all ideally located for wiring in the wall mounted string. I'd put in a nice service loop so I can install an additional combiner box this summer when it's warm and I have the time.

Thanks and let's please keep my thread about vertical panels instead of ideas on how to melt the snow. I appreciate all the ideas to melt but I don't think any are practical when I am 1,200 miles away. Hell a snow rake isn't proving to be very practical.

 

[Hedges]

Or if I am willing to spend hundreds more could I install two of these Panasonic 340w panels in parallel to get approx 9 amps of charging?

Panasonic 340W Solar Panel 96 cell VBHN340SA17 Monocrystalline White - A1 Solar Store

Panasonic 340W VBHN340SA17 Solar Panel 96-cell combines great aesthetics and efficiency with proven reliability | Reviews, pictures - A1 Solar Store

a1solarstore.com

No reason to spend $1/watt. For the $730 you'd pay for two of those panels, you could get several times the wattage from SanTan, truck shipping of a pallet to freight terminal included. Or, locate panels within driving distance. You could probably get 2500W of panels from Santan, delivered.

 

[hammick]

No reason to spend $1/watt. For the $730 you'd pay for two of those panels, you could get several times the wattage from SanTan, truck shipping of a pallet to freight terminal included. Or, locate panels within driving distance. You could probably get 2500W of panels from Santan, delivered.

Thanks Hedges. Any guess what charging amps 750 watts of the cheap Santan Panels would give me. I'm guessing around 5 amps. Assume vertical mount and full low southern sun. I'm trying to put a bandaid on this problem until summer.

Thanks.

 

[Hedges]

I forget what your voltage is.
In cool weather, probably get 90% of STC watts so close to 700 watts from 750W (STC) of panels.
What does insolation chart show, maybe 2 hours effective?
So 1400 Wh, which would be 100 Ah into a "12V" battery at 14V, 50 Ah into 24V battery, 25 Ah into 48V battery.
Assuming MPPT charger.

With SanTan panels $50 each for 250W, and shipping a pallet $100 to $200, probably get more than just 3 panels. You can get an extra MPPT charge controller too if needed.

 

[hammick]

I forget what your voltage is.
In cool weather, probably get 90% of STC watts so close to 700 watts from 750W (STC) of panels.
What does insolation chart show, maybe 2 hours effective?
So 1400 Wh, which would be 100 Ah into a "12V" battery at 14V, 50 Ah into 24V battery, 25 Ah into 48V battery.
Assuming MPPT charger.

With SanTan panels $50 each for 250W, and shipping a pallet $100 to $200, probably get more than just 3 panels. You can get an extra MPPT charge controller too if needed.

I'm 48 volts 16s 280ah Lishen bank. Sometimes my eyes glaze over trying to size solar panels. I found the midnight solar string sizing calculator. I was overthinking this. Charging amps is as simple as total watts divided by charging volts I guess. So 750/55 = 13.6 amps Obviously this is best case scenario which I will not see with vertical panels.

I need to measure but maybe I will do three of the 350 watt panels which are $100 each. 19 amps charging. Claim to be installed but never powered. No manufactures warranty (just 1 year Santan warranty) but I'm guessing those warranties are useless anyway.

 

[MisterSandals]

I need to measure but maybe I will do three of the 350 watt panels which are $100 each. 19 amps charging.

What is there to measure? The specs for the panel should be on the back of the panel.
What do you mean "19 amps charging"? Are you referring to the panel amperage? That too is on the panel label.

 

[hammick]

What is there to measure? The specs for the panel should be on the back of the panel.
What do you mean "19 amps charging"? Are you referring to the panel amperage? That too is on the panel label.

19 amps is what I have calculated will going to my batteries with three 350 watt panels in series. Obviously I will see less since my inverter is powering light loads when I'm not there and the panels won't be at the ideal angle.

I can't just add the maximum power current of each panel, right? That would be 27 amps.

My math for charging amps is 1050 watts (three panels) divided by 55.4 volts (my bulk charging voltage) = 19.3 amps

 

[MisterSandals]

19 amps is what the Midnight Solar calculator says

Okay.

(350w x 3) / 55v = 19a

 

[GregE]

Vacation place in Montana that hopefully will be our retirement home. 2,400 sq ft Monitor style barn but only 800 sq. ft. is living quarters. If it becomes our permanent retirement place we will build a small house and the current living quarter will be a guest home.

In hindsight I wish we had ground mounted the panels. Last winter was the only time in five years since we built that the panels were covered in snow for a long stretch of time. But last year was the first year we kept the inverter on when the place was vacant. So they could have been covered before that and I wouldn't have really known. When I started leaving the inverter on when vacant I also configured my Schneider Conext equipment for remote monitoring.

I am installing a 16s 280ah LifePO4 battery in December so I'm thinking I could probably get away with 900 watts of panels facing South to keep the batteries charged when we aren't there and the panels get covered.

Even with a ground mount if I'm not there I would have to have somebody come by and clear the panels.

So installing panels on the South wall is the best and cheapest solution I think. Last time I had my installer add 900 watts of panels it was $1,200 Might be a little cheaper for a wall mount. Actually I could do it myself but I can take the 26% tax credit for his labor and he does a good job.

Some better shots showing why living off grid is worth it:

View attachment 25747

View attachment 25748

Just Beautiful