keeping snow off of the solar panels

[asheets]

This is the 1st year I've been playing around with PVs.  I noticed the day after the big storm that porch lights were off and my inverter wasn't running.  A quick check showed my bats at just under 11V, and nothing was coming from the panels at all.  Of course, they were covered with snow.

I'm not going up onto the roof to get snow off the panels anytime soon (too much ice).  Anybody have any suggestions on how to deal with it, or is this just one of the things about solar that have to be lived with?

[ghurd]

Depends on where you live.

NE OH, I fix them at 52 degrees tilt. Longitude plus ~11.

It doesn't get so cold it stays frozen for long, IF there is enough sun to do any charging.  Even on the sunny day or 2 a year it stays below 10'F.

This is a Great Lakes snow belt.

Between the tilt and a bit of sun reflecting onto the rear, the snow and ice slide off.

One guy hits it with a "nerf" football to get a patch the sun can reach, then the snow melts off quickly.

G-

[pyrocasto]

Maybe a little bit of rock salt thrown up there, anything just to get a little sun on a part of the panel. As said after that it heats up quick and the rest will be gone.

[hiker]

what about -- breakin out the garden hose and blasting off the snow......

just stand on a ladder and blast away.....               ?

[DanG]

I watched a neighbor clean his gutters from the ground this fall with a leaf blower.

A standard roof gutter downspout is ten feet so one slipped over the end of a leaf blower will give you at least a twenty-foot reach plus however far the jet of air will carry...  I have wondered if it would be worth plumbing downspouts together and making a permanent snow removal system, even attaching a 120VAC electric blower into it so it could be run remotely. It wouldn't work in all types of snow but would be easier than raking it off.

The best roof snow-rake I've seen is two-inch wheels on an axle that trails a slick sheet of plastic behind it, the roll is about 16 feet long & handle is about 24-foot long. Ice and snow have near zero friction on the plastic so you can move tons of snow using its own weight against it on a sloped roof. Very satisfying to hear the "WHOOOMPH" when it hits the ground too. Something similar to an automatic window roller blind of the same slick plastic would be do-able if one were especially gifted at tinkering, have it knife up from bottom and retract to get powder snow off...

[ghurd]

I'm offended!

Neat idea, but I wonder how it'll work.

Being cheap, I use very little rock salt on the sidewalk.  Usually it makes little holes in the snow the size of the salt... thats all.

Maybe the tilt will help diffuse the salt?

Can't hurt? Wondering about salt on the frames etc.

G-

[Bruce S]

Worked for me

I didn't have to climb on a ladder and I was sure to use the COLD water.

I've seen people blow out their windows from the thermal schock when using hot water.

Pressurized water hose worked like a charm, even clear Ice will allow some charging.

Cheers

Bruce S

 

[richhagen]

I mechanicaly scraped the snow off of mine, but with a flat roof, I can get to them.  I waited till the batteries were down and I had to go up there of course, I was hoping the sun would do the job for me.  Rich

[boB]

This is another reason why pole mounts are good.  During the summer, when

the sun is lower on the horizon anyway, you can tilt them more verticaly so

that the snow falls off, as was already said.

If the modules are frozen, especially, I would hesitate to pour too warm

of water on them because the glass can crack and ruin the module (modules)

my 2 Centz

boB

K7IQ

[nailed]

I use the heat tape for keeping pipes form freezing on the frames.  I'll turn it on for a few hours before the sun comes up.  Once the sun hit's the edges of the panels the ice will slide off.  I normally get ice not snow.  

[Titantornado]

Ya beat me to it boB.  I was thinking one more plus for tracker units.  Snowy day?  No problem.  They will be parked vertically.

[asheets]

I'm in Loveland CO, just west of the Interstate, south of the Dans but not in the mountains.  You can tell where, in my attic, I'm lacking for insulation because that is where the snow ISN'T.

[asheets]

That would involve me getting up on the roof in winter.  And, I'm opposed to salt for environmental reasons.

[asheets]

I've actually been thinking about moving the panels off the roof and onto a pole-mount in the back yard.  But, I promised to keep "ugliness" hidden from the wife while in the midst of my hobbies

[GaryGary]

Hi,

I use a thing called a "roof rake" to pull the snow down off the part of my roof that makes ice dams -- I'd guess the same thing would work for PV panels.

Its basically a 2 ft wide by 5 inch blade on a long handle.  The blade is mounted perpendicular to the handle.  You just position the blade, and pull on the handle.

Around here, most of the hardware stores sell them.

http://www.roofrake.com/Productpages/deluxeroofrake.asp

Gary

[TomW]

Mine are on a pole in easy reach but if they were up on a roof I would locate a wiper motor / arm / blade off a car or truck and mount it so it can just swipe off part of the panel. If there is any sun at all it should allow the rest to slide right off.

Just what I would do if I had that problem. The heat tape idea would work too. Experience shows that if any little bit gets sun it quickly melts the rest off.

Cheers.

TomW

[nailed]

I would love to set up some wiper blades on mine but I always get ice.  My first year I put a sprinkler up there and would run cold water to melt it.  But one day I didn't get all the water out of the hose.  no way I'm getting up there with the ice to make sure the hose drained.  

But I have 12 panels up and 6 more in the box I'm about to install.  That would be a lot of motors.  It would be a good way to get into some magazines.  I will say that I only have heat tape on a few of my panels and I'm not putting them on all of them.

[boB]

Of course there's also the possibility of DRIVING the PVs until they draw

at least their rated, and maybe up to 2wice their rated forard current which might

melt the snow off of them.

You need to drive them at slightly higher than the open circuit voltage (VOC) that

the cell temperature dictates, then all of those diodes (cells) will start

conducting and dissipating heat.

boB

[badmoonryzn]

Totally useless info:

OH for heavens sake, I thought you guys were men. I just squirt a little bit of water, or I softly drag some plastic, how about I gently rub them until the snow oozes off, then there's, I put up some heat tape to gently melt off the snow or softly throw some rock salt. Damn, your kidding right? Your men for heaven sake use your manly ideas like: Napalm or a flamethrower is nice on a cold winter day, just blast the stuff of in a wild frenzy. Who cares if the neighbour's house burns it will help keep the ice off your panels for a while.

Then there is the good old nitrate class, hang a bag or two of blasting pellets on a stick up in the air and touch it off and the shock wave will displace the snow and ice. I always enjoy using detonation cord, man is it fun, way more fun than the law allows. You can get a spool of 100 feet of so and wrap it in a spiral up the pole. When you shoot it and the pole will look like a screw. The shock wave again will displace the ice and snow and most likely remove the neighbour's windows but the heat loss from his house will keep the snow off for a while.

See how useful the neighbour has become. And you turned him in for growin pot, aren't you ashamed? My all time favourite is to take a pint of homemade nitro and put it in to little vials and lob them over the fence to the house next door and the dog starts barking like mad and as soon as the guy comes out of the house I lob another into the back of his car where I have a hidden surprise under the gas tank. The car then jumps up off the ground about twenty feet and lands right on top of the house in a giant burning wreck. The ensuing commotion causes plenty of heat in the air by all of the yelling and running around and panicking until the swat team gets there. As the neighbours get hauled to jail for terrorism.

Oh yea, you called the FBI and turned them in for suspicion of running a terror cell and of coarse you left your bags and boxes from all of the nitrates, glycerines, sulphuric acid, timers, loose cell phones, pictures of Osama and his buddy So Damn Insane. Damn, you think you know your neighbours! Oh well, you had to clean off the cells so you can watch the repeats of Fantasy Island. Dah plane, Dah plane! Good luck, have fun and enjoy the holiday season!

Badmoonryzn

[TomW]

Bad;

Uh, thanks for confirming my suspicions that you are just here to poke fun at folks.

T

[asheets]

Ummm... I have turned my neighbor in for pot, and I had his brother deported too.

I've decided to just go ahead and move the panels to a ground mounted pole.  In talking with the neighbors (some of the non Hab for Humanity houses in the neighborhood have PVs and hot water panels on them), the prevailing thought is to move them to ground level.  My southern neighbor won't mind -- and in fact likes the idea of the panels adding extra height to the privacy fence.  The roof idea wasn't that great anyhow, as the H4H houses here (I got mine 2nd hand) have east and west facing roofs.

[ghurd]

I don't care for most 'factory made' pole mounts. They wag in the wind too much for me. Partly because most I see are quite high, maybe to get them closer to the sun? LOL

Maybe use 2 poles for the mounts, or use a 4X4?

Nobody wants a replay of Tom in NH's previous situation!

G-

[ghurd]

This is just after the recent blizzard, 10"? of snow, but the wind swept area helped.

The icecicles show (a little) in front of the black brackets on the right hand side of both panels.

There was not much sun at all, but they got warm enough to make icecicles!

G-

[asheets]

Since my setup is still quite small (consisting mostly of Harbor Freight 1W battery maintainers that I managed to grab for $4 each), my idea was scab a 2x4x8 to each of my privacy fence's set 4x4 posts, then attach the PVs to the 2x4 facing south and angled at 30 degrees off of vertical.  There's a dead space between my fence and my southern neighbor's fence, so the scabs won't even be noticible.