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Small Cabin Forum / Off-Grid Living / solar panel angle in winter
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MI drew
Member
# Posted: 18 Nov 2014 15:35
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OK, I did the math and my panel angle should be 69deg as shown in the picture. Here's my issue, we get a ton of snow where were at. We got 12+ today on top of the 20 already had on the ground with only 2" sticking to the panel. My question is, can I get away with 90 deg in the panels or will I loose something? The mount I made is totally adjustable so I can do whatever. The crazy part is that even with no sun and the white out you see I was getting 2.5amps after I cleared then off. I came home today and was able to clear them off the 4 days I was up but we only go up about every other weekend. Just want to make sure my batteries stay topped off. Also I have a MPPT charge controller.





MtnDon
Member
# Posted: 18 Nov 2014 15:56
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If you are concerned about what goes on when you are absent just tilt them to 90 when you leave. With no use the system will carry a full charge with no problem. You may even find a slight enough difference with the panels at 90 degrees that it does not matter, when you are there using power. Try it and see. At worst you will have to tilt and re-tilt panels each time you arrive and leave.

groingo
Member
# Posted: 18 Nov 2014 16:39 - Edited by: groingo
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Makes me wonder if at 90 that you might pick up some reflected energy from the snow as well?

creeky
Member
# Posted: 18 Nov 2014 16:55
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re: 90. that's what I've heard. you get some reflection off the snow and that adds to your solar production.

I'll be testing this theory by pitting two identical solar arrays against each other this winter. One at 60 and the other at 90. Should be fun.

MI drew
Member
# Posted: 19 Nov 2014 11:50
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Thanks the input. Didn't even think of the reflective energy off the snow on the ground. 90deg it is. I will be adjusting when I go back up. I guess I'd rather loose a little amount of power at the wrong angle that loose all of it at the right angle. Got another foot coming by Friday... So no sun for a while.

Steve_S
Member
# Posted: 19 Nov 2014 13:11
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shivers, shivers & more shivers.... Clean White Snow is a better reflector than mirrors... Arctic Sunburns ;) Gotten a few of those.

I'd be interested to know how your experiment works out Creeky... If you can do real time power generation monitoring, you could adjust and take a reading, and fiddle a bit between readings to see what the results are...

slgerber
Member
# Posted: 19 Nov 2014 16:15
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I too think that 90 degrees would be the best compromise, but I just wanted to throw out another idea. Since the sun is low on the horizon during the snow season, another possibility would be to build some kind of simple temporary roof over the solar panel that would shed snow but would allow the low angle sun to come in under the roof.

ColdFlame
Member
# Posted: 19 Nov 2014 16:54
Reply 


The company I work for sets up wireless networks in open pit mines. We sell solar trailers to some of these clients to put wireless access points in areas of the mine where there is no fixed infrastructure. They are quite far north (Fort MacMurray, Alberta area) and we instruct them to tilt their solar panels on our trailers to 90 degrees during the winter months. As mentioned by the others, you have the benefit of some sun reflection off the snow, but the primary purpose is to keep the snow from "sticking" and covering the panels of course. It works well for our needs.

MI drew
Member
# Posted: 2 Dec 2014 06:40
Reply 


Well I adjusted the angle to 90 and no more snow. Still hard to get a idea of a difference with what maybe lost in production at that angle. We were up for 4 days and only saw the sun for a couple of minutes. Lol. At one point at 11am and indirect sun I was seeing 14amps. still had to run the genny a couple hours each night. Looks like it is now time to start adding more batteries. Only at 210ah now, thinking 2more sets getting me to 630ah should get me through a winter weekend without the need for the genny.


creeky
Member
# Posted: 2 Dec 2014 09:05
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looks good. i forgot about this post and started another similar. oops.

here's my 60 degree angle from the other post. I see about a 30% increase in power from the summer angle to winter (tested summer 2014). Or about 15% by season. Kinda neat. When I went from summer to fall and fall to winter ... on my movable array ... I saw "current limiting" the next day in full sun. Which indicated a marked improvement in power production.
2ndkw.jpg
2ndkw.jpg


groingo
Member
# Posted: 2 Dec 2014 10:40
Reply 


Is the power uptick because of angle or the cold weather which is typically good for the 15%?

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