Snow removal

[Anthony A Bobo]

I live near Philadelphia and we received a lot of snow this year. Sometimes my panels are covered for up to 5 days with minimal power production. Thinking of a way to get that snow off my roof. Came across these guys http://roofrake.com/Productpages/snowpro2.asp looking at the 30' extension pole the the rubber device they claim made for solar panels. $150 seems like a hefty cost. Anyone here have this model and if so is it effective in removing snow from your panels?

John

Clearing off the snow from solar panels has to be done little carefully. You cannot use snow blowers or plows to clear that snow. So i think the best way is to get the help of any snow removal company. I would suggest you Infinity Gardens as i have personal experience with them. For last few years they have been cleaning the snow from my friends house. Their service is really appreciable. Here is their link. You could just check it out. infinitygardens.ca/residential/.
I hope the information will be useful to you.

[J.P.M.]

RE KRC MTU Equip: I don't know what they have. I'm working with them on a tracking project and saw the site but didn't discuss their findings/gear...yet.

Not really sure about their testing either. I know they change the angles, gaps and positions of the panels.

Thank you.

J.P.M.

[FishGun]

RE KRC MTU Equip: I don't know what they have. I'm working with them on a tracking project and saw the site but didn't discuss their findings/gear...yet.

Not really sure about their testing either. I know they change the angles, gaps and positions of the panels.

[peakbagger]

I have considered installing some vents from my attic and pumping warm air from the house under the lower edge of the panels. I heat with wood and could set up a separate glycol zone with blower so the heat would be effectively "free". What stops me from doing it is cutting a holes in my roof. No matter how well a roof vent is flashed its a place where snow and rain can figure a way in if the weather is nasty enough.

[J.P.M.]

The Keeweenaw Research Center at Michigan Tech Univ has been doing some snow shedding studies for a couple years. I'm working with them on some tracking projects so I should be able to learn a bit more about their findings in the next few months...or maybe when spring breaks thru. It pretty much snows up there every day!

http://mtukrc.org/solar.htm

Question: What types of weather equipment does your facility have. Looks pretty professional.

[bcroe]

On cold day with the wind blowing its hard to justify spending 15 minutes scraping snow off when the net result is less than a $1 of generation (but I do it too).

More like 90 minutes here. The gain is all the sun till the next storm, hundreds of KWH.

The Keeweenaw Research Center at Michigan Tech Univ has been doing some snow shedding studies for a couple years. I'm working with them on some tracking projects so I should be able to learn a bit more about their findings in the next few months...or maybe when spring breaks thru. It pretty much snows up there every day! http://mtukrc.org/solar.htm

I only see snow melting off some panels; must be warmer there. Using only the sun? And they
seem to have a gap between panels, so snow only has to slide down one. Are they doing
anything else?

Vibrate the snow off; never thought of that. Works on ice too? OK put a big voice coil on the
back and try different frequencies. Find resonance and the panel shatters like the glass it is.
But that only bounces the snow up and down. Lets put the driver on the top edge, so the
vibrations travel down it. And take the snow with them? Think I'll try that experiment in 2027.
Bruce Roe

[russ]

The Keeweenaw Research Center at Michigan Tech Univ has been doing some snow shedding studies for a couple years. I'm working with them on some tracking projects so I should be able to learn a bit more about their findings in the next few months...or maybe when spring breaks thru. It pretty much snows up there every day!

http://mtukrc.org/solar.htm

Excellent - looking forward to reading what you learn!

[FishGun]

The Keeweenaw Research Center at Michigan Tech Univ has been doing some snow shedding studies for a couple years. I'm working with them on some tracking projects so I should be able to learn a bit more about their findings in the next few months...or maybe when spring breaks thru. It pretty much snows up there every day!

http://mtukrc.org/solar.htm

[SunEagle]

Its true, a big reserve from summer is covering winter losses. But I'm still not happy to
see good sun and inverters not working hard. There are plenty of times in winter when
things could be running better. AND. I want the amount of manual intervention at an
absolute minimum.

The problem with ice, is I can't get it off till there is a really sunny day. So in the meantime
production is cut every overcast day from maybe 45 KWH to 22 KWH.

I can see locations for panels to better avoid winter shading. South facers could use an
easy power tilt for storms, and to better match the season. Having a couple short rows in
the middle would do better than a single very long row. Panels could be mounted
horizontally with a gap so snow wouldn't have to move nearly as far to be clear. Having
remeasured the whole back acre, I'll be watching how the sun does on tentative relocations
for 6 months. And maybe asking my south neighbor about those 2 trees in the space
between lots. Bruce Roe

Might be time to think about installing that panel vibrator to shake the snow off.

[peakbagger]

On cold day with the wind blowing its hard to justify spending 15 minutes scraping snow off when the net result is less than a $1 of generation (but I do it too). Off gridders on the other hand will do anything to avoid running the generator.

[bcroe]

My snow experience is as previously mentioned:
- get the majority off soon after a storm and the rest will come quick when the sun comes back.
- the bottom frame of the panel tends to be a dam. Snow/water and ultimately ice catch and bond pretty tightly at the bottom lips.
- the joint between the panels is a good snow catch point unfortunately.

Black framed panels (and all black panels) are better than natural and frameless panels at reasonable angles shuck snow like crazy! I would say frameless panels at angles (maybe adj for winter) with a 2-3" gap between the vert joint and ground mounted (so no piling in front) would be snow throwers!

But having said this I really believe that the few hours of sun lost due to snow are pretty much not worth the time/cost for my ground mounted panels in Michigan. Snow means clouds. Dec/Jan/Feb are horribly cloudy days anyway. Say you lose half of the sunny days...what is that? 7 short days in 3 months!?
But yeah...I'm still out there brooming them off anyway!

Its true, a big reserve from summer is covering winter losses. But I'm still not happy to
see good sun and inverters not working hard. There are plenty of times in winter when
things could be running better. AND. I want the amount of manual intervention at an
absolute minimum.

The problem with ice, is I can't get it off till there is a really sunny day. So in the meantime
production is cut every overcast day from maybe 45 KWH to 22 KWH.

I can see locations for panels to better avoid winter shading. South facers could use an
easy power tilt for storms, and to better match the season. Having a couple short rows in
the middle would do better than a single very long row. Panels could be mounted
horizontally with a gap so snow wouldn't have to move nearly as far to be clear. Having
remeasured the whole back acre, I'll be watching how the sun does on tentative relocations
for 6 months. And maybe asking my south neighbor about those 2 trees in the space
between lots. Bruce Roe

[FishGun]

My snow experience is as previously mentioned:
- get the majority off soon after a storm and the rest will come quick when the sun comes back.
- the bottom frame of the panel tends to be a dam. Snow/water and ultimately ice catch and bond pretty tightly at the bottom lips.
- the joint between the panels is a good snow catch point unfortunately.

Black framed panels (and all black panels) are better than natural and frameless panels at reasonable angles shuck snow like crazy! I would say frameless panels at angles (maybe adj for winter) with a 2-3" gap between the vert joint and ground mounted (so no piling in front) would be snow throwers!

But having said this I really believe that the few hours of sun lost due to snow are pretty much not worth the time/cost for my ground mounted panels in Michigan. Snow means clouds. Dec/Jan/Feb are horribly cloudy days anyway. Say you lose half of the sunny days...what is that? 7 short days in 3 months!?

But yeah...I'm still out there brooming them off anyway!

[bcroe]

If you have the opportunity, remove the snow from the panels after the storm passes and then there will be little chance of it freezing as ice on the panel surface. I realize that if you are not around at the time, it may not be possible?

I give my panels a brush off in the morning if there's even a bit of snow collected along
the bottom, as that will eventually turn to ice.

Yea, not always here. And I'm not likely to go out except just as the sun rises. So a big
change in temp overnight could cause the ice. Can do around 25 KWH as iced.

BUT, it got warm enough on the 11th, got off all the ice, did 47 KWH thru overcast. Today
the sun came out, inverters were hard into clipping. A short day, the low sun has a lot of
time shaded. But managed 76 KWH, enough to run my heat pump 35 hours.

Am planning the next generation of panel positioning, need 6 mo of watching first. Bruce Roe

[northerner]

Temperature finally rising here, decided to have another shot at the ice.

Here is what the storm a week ago left me. Snow fell, some sun, snow started sliding off
the panels. Then temp dropped to zero F or lower, snow against the panels froze, and its
been like this ever since. Looking at this, I'm thinking there would be a lot more panel
exposed (esp the lower ones) if there was a gap of some inches between panels. Snow
from the upper one would fall through to the ground, instead of piling up on the lower panel.
Guess turning the panels horizontal might help too.

If you have the opportunity, remove the snow from the panels after the storm passes and then there will be little chance of it freezing as ice on the panel surface. I realize that if you are not around at the time, it may not be possible?

I give my panels a brush off in the morning if there's even a bit of snow collected along the bottom, as that will eventually turn to ice.

I have more of an issue starting my NG converted generator when cold, but that's a whole nother topic.

[bcroe]

I don't see any safe way to get the ice off. Its pretty thin, so keeping loose snow off helps
some sun get through. Not enough to melt ice at 5F, but should make at least 25 KWH today.
Not seriously worried; built my reserve in summer, don't have high expectations for Dec/Jan.
Bruce

Temperature finally rising here, decided to have another shot at the ice.

Here is what the storm a week ago left me. Snow fell, some sun, snow started sliding off
the panels. Then temp dropped to zero F or lower, snow against the panels froze, and its
been like this ever since. Looking at this, I'm thinking there would be a lot more panel
exposed (esp the lower ones) if there was a gap of some inches between panels. Snow
from the upper one would fall through to the ground, instead of piling up on the lower panel.
Guess turning the panels horizontal might help too.

Turning around the brackets on the lower panels should form a 2" gap. Redrilling some
mounting holes could move the upper ones 2 or 3 inches more, give me a decent gap.
Something else to do in summer.

Meantime the prediction was increasing (from -10 F) to + 18 F, partly cloudy. Here that
means the sun will be strong in the AM, then cloud over in the PM. I tried to go out at
the peak to clear some panels. Good sun, output was the highest since the ice, 6 KW. I
managed to get the ice off all the upper panels, cleaned the lower panels on one string.
Then the clouds came through, and no more could be done. Tomorrow should be 25 F, so
the job ought to get finished then.