Worst solar production day so far.

[Mb190e]

Due to the 10 inches snow we received throughout the day and another 4 inches tonight. We managed to squeak out on the measly .5 kWh from our 8.1 kW system. We did use over 60 kWh's today with the addition of our heat pump, definitely used up some of the saved kWh's from this summer.

[Mike90250]

Just wait, the days are getting shorter. (warmer, but shorter)

[myfriendSUN]

Due to the 10 inches snow we received throughout the day and another 4 inches tonight. We managed to squeak out on the measly .5 kWh from our 8.1 kW system. We did use over 60 kWh's today with the addition of our heat pump, definitely used up some of the saved kWh's from this summer.

I had 0.45kWh, less than 1" snow, yesterday.

[Mb190e]

I don't know how long it's going to take the snow to slide off or melt off the panels. zero production yesterday and zero today. Panels are 27° tilt.

[bcroe]

I don't know how long it's going to take the snow to slide off or melt
off the panels. zero production yesterday and zero today. Panels are 27° tilt.

If you were in NW IL, it might take till April. That is one reason mine are within reach,
on the ground. Standing them straight up for the time there is snow on the ground helps,
and they will also be getting energy from reflections off the snow.

When it snows overnight, I have them cleared by the time the sun is up. On the less
frequent times it snows during the day, production drops to a few percent. I suppose
that comes from reflected sun on the under side. good luck, Bruce Roe

[subdriver97]

I don't know how long it's going to take the snow to slide off or melt off the panels. zero production yesterday and zero today. Panels are 27° tilt.

How counter-productive to power generation would it be to design a panel with a defroster? I wonder if you could salt your panels (that would leave a nice nasty residue...)?

[russ]

How counter-productive to power generation would it be to design a panel with a defroster? I wonder if you could salt your panels (that would leave a nice nasty residue...)?

No problem but you are talking about electric resistance heating - it would use very much power

[subdriver97]

No problem but you are talking about electric resistance heating - it would use very much power

solar panel windshield wipers?

[russ]

solar panel windshield wipers?

defrosters are not wind shield wipers - two different things - adding complexity is gonna cause more head ache than it is worth.

[subdriver97]

defrosters are not wind shield wipers

who said they were the same thing? also, it was a joke... ease up a little...

[subdriver97]

No problem but you are talking about electric resistance heating - it would use very much power

Does than mean you definitively know that the heater would use more power than a panel would have generated minus the snow? What numbers could we assume for the heater power usage and panel power generation?

[russ]

Does than mean you definitively know that the heater would use more power than a panel would have generated minus the snow? What numbers could we assume for the heater power usage and panel power generation?

It is a loser and has been brought up many times and beat to death many times - if you want then you figure it out.

[subdriver97]

It is a loser and has been brought up many times and beat to death many times - if you want then you figure it out.

If that is the case, you can just state so. There's no reason to re-hash the exercise if it has been performed in the past. Thanks for your wisdom. It is tremendously enlightening.

[bcroe]

I don't know how long it's going to take the snow to slide off or melt off the panels. zero production yesterday and zero today. Panels are 27° tilt.

Here enough snow accumulates, if it all slid down (toward the sun) the pile would be so high
to easily block the sun. I counter by pushing as much as practical up over the top and behind,
or off the sides. Still with panels at 20" ground clearance, snow in front needed to be moved
farther away. Here are some pics of what happened here; not massive snow falls, but none
of it melted till spring.

Measurements here indicate a string could be disconnected and fed to the string to defrost it.
It would take so much power that only a fraction of my total could be done at a time. The
wiring complexity and power control would be a major project. However, it should take less
than an hour, so in a few days you might come out ahead on energy.

My conclusions are that panels should be elevated to near vertical for the snow season.
Perhaps mounting them about twice as high above the grounds as these would deal better
with accumulation, but hinder manual clearing. Ideal might be to tilt them slightly past
vertical for a storm, then back after. That would require a motor, but maybe not so hard
to do after the tilt mechanism is worked out. Voids the panel warrantee I'm told. Here
the wind would be blowing the snow toward the back of the panels, or alongside, not head on.

Bruce Roe

[Bikerscum]

Ideal might be to tilt them slightly past vertical for a storm, then
back after. That would require a motor, but maybe not so hard to do after the tilt mechanism
is worked out. Voids the panel warrantee I'm told. Here the wind would be blowing the snow
toward the back of the panels, or alongside, not head on.

Bruce Roe

Makes me wonder if that could be done with just double acting air cylinders. Cheap, simple, powerful.... and with clevis mounts at the ends can be a structural part of the mount.

A shop compressor with a two way valve for control.

Get on it. lol