Sun hours

[bcroe]

My generation isn't much different this year. But the heat pump has helped reduce use in the fall. Now we
have had such warm weather (that means well above freezing in NW IL), energy use for warming the house
(to 74 deg) has been way down. At this rate my 2015/16 KWH reserve is way above previous. More like
12,600 KWH instead of 7000 last year. Perhaps I'll turn up the temp in the shop to use some up. Bruce Roe

[bcroe]

Pv snow gap
Today was the setup for another snow experiment. I have panels 2 high, meaning snow must
slide a long way to be cleared off 2 panels, and the pile of snow gets pretty big while clearing and
at the bottom. On one support of 6 panels I moved the upper panels 4" higher and the lower panels
2" lower for a 6" gap between them. Snow will only need to slide half as far, in half the quantity
before falling through the gap.

On the next support of 6 panels, I just moved the upper for a gap of 4". This winter will be the
test: does the gap work and how big should it be? Did it in the afternoon, had just enough sun
time left to make sure all were still working properly. Bruce Roe

3 days ago we had a snow & sleet storm with a few inches of stuff. Its been too cold since to
remove the ice frozen on, but I went out to see what happened without my intervention. Groups
of 6 panels (2 portrait high) had snow slide down over 2 panels so that the upper panels were
60% covered and the lower panels were 100% covered. The lower panels were COMPLETELY
CLEAR where there was a gap. The upper panels had snow slide down into the gap. The upper
panels were about 40% snow covered above a 4" gap, and 25% covered above the 6" gap.

Results of manual snow clearing were good, but self cleaning were even better. By a year from
now, there will be a 6" gap for all 12 platforms. If I build any more platforms, panels will be landscape
(to reduce the distance for snow to slide off). I am wondering, why no one ahead of me has made
such a suggestion? I expect this won't work on a roof mount, as the gap would fill up instead of
dropping to the ground.

Next time we see the sun and above freezing temps, will see about getting the rest of the snow
off my south facing panels. Despite the gloom, my snow free near vertical east-west facing panels
managed to eek out 17KWH. Bruce Roe

[inetdog]

Thanks, I have no idea how to find that thread, or if I even saw it. Pictures on old posts seem intact. When I try
CAMERA, SELECT FROM PHOTO ALBUMS, get message
Error: You have no uploaded photos or albums to choose from
Bruce Roe

I think that there were some subtle changes in the database that kept some features from coming over. There is an Album feature that does not appear to be working, and downloading new images is intermittent.

Try posting comments and bugs in this thead: https://www.solarpaneltalk.com/forum...lar-panel-talk

[bcroe]

Thanks, I have no idea how to find that thread, or if I even saw it. Pictures on old posts seem intact. When I try
CAMERA, SELECT FROM PHOTO ALBUMS, get message
Error: You have no uploaded photos or albums to choose from
Bruce Roe

[inetdog]

OK, everything is changed. First I had to find my password, did. The LAST button on the pages seems to be missing; need to go to the
bottom to at least see the number. If there is a NEXT THREAD button, I can't find it. Bruce Roe

Some things will have to be done differently in the new format. So far there are still ways to do almost everything that people want.
Notice that at the top of this page there is currently a "Page N of 8" display. That tells you that there are 8 pages, and if you type a page number into the first box you will be taken directly to that page.
In the list of pages at the bottom of the page the last page number of the thread is always the one directly displayed at the end of the list.

Next thread seems to be missing completely, but I never used it so I did not notice. Or do you just mean Next Page?
The arrow buttons after the Page N of M display will move you one page forward or backward. If you are at one end of the page list only one of the two arrows will be active.

If you are not already at the last page, there will be a Next button after the page list at the bottom.

Dave

P.S. If you post your comments and questions about the new software installation in the thread where Solar Pete announced the change they will be more likely to be seen and answered by staff.

[bcroe]

OK, everything is changed. First I had to find my password, did. The LAST button on the pages seems to be missing; need to go to the
bottom to at least see the number. If there is a NEXT THREAD button, I can't find it. Bruce Roe

[bcroe]

Today was the setup for another snow experiment. I have panels 2 high, meaning snow must
slide a long way to be cleared off 2 panels, and the pile of snow gets pretty big while clearing and
at the bottom. On one support of 6 panels I moved the upper panels 4" higher and the lower panels
2" lower for a 6" gap between them. Snow will only need to slide half as far, in half the quantity
before falling through the gap.

On the next support of 6 panels, I just moved the upper for a gap of 4". This winter will be the
test: does the gap work and how big should it be? Bruce Roe

Today was the first gap test, went pretty much as I expected. Snow was willing to drop into
a 6" gap (instead of sliding onto another panel). A little coaxing was needed to get it down
the 4" gap. I will probably go with 7" or 8" gap to make it easy in the future. I will need to
either turn some panels around, or use some short extension cords to cover the gap.

It was very nice not seeing snow on one panel NOT sliding down onto another panel.

Snow storm started 3 pm Fri, ended 2 pm Sat at about 10". That's different, the storm usually
ends by sunrise. Low light out there; the inverters didn't have enough power to start this
morning. However the near vertical panels facing E and W took just a tap and the snow fell off.
They made enough energy (3KWH) in the next hour, I can still say it has made some energy every
day. Need to work on a motorized tilt system. By sunset all panels were cleared. Bruce Roe

[bcroe]

Bruce,I know this sounds strange, but I actually look forward to pushing snow. It means the next day there will be full, bright, cold and maximum production. I know you can relate as a mid-westerner.

I'm of course looking forward to testing my panel snow gap theory. Generally the snow falls during
the night here, so I can be seen getting them cleaned off just before sunrise or whenever the
snow stops. Bruce Roe

[DanS26]

You are so right. I am more worried about wheeling out the 27 hp, AWD snow blower. The temps
have finally dropped below freezing; we still had blooming flowers this morning. I started using
partial resistance heat at night, so the heat pump doesn't have to work so hard (I might have a
big energy surplus this winter). Still having decent PV production about half the days; hope it
doesn't go 27 days in a row without seeing the Dec sun like last year. With the snow, only did
30 KWH today.

Just Tuesday I finished setting up the upper-lower panel gap, so that when I push the snow
(pretty much as DanS26 described), I will only need to push half as much, half as far, to the
nearest gap. Only 2 wires now cross each gap to the upper panels now, each securely tied
to a main support. Needed a couple short MC4 "extension cords" to do the extra distance.
Bruce Roe

Bruce,I know this sounds strange, but I actually look forward to pushing snow. It means the next day there will be full, bright, cold and maximum production. I know you can relate as a mid-westerner.

[bcroe]

Bruce
Based on the weather forecast you may have to use your snow sweeper this weekend.

You are so right. I am more worried about wheeling out the 27 hp, AWD snow blower. The temps
have finally dropped below freezing; we still had blooming flowers this morning. I started using
partial resistance heat at night, so the heat pump doesn't have to work so hard (I might have a
big energy surplus this winter). Still having decent PV production about half the days; hope it
doesn't go 27 days in a row without seeing the Dec sun like last year. With the snow, only did
30 KWH today.

Just Tuesday I finished setting up the upper-lower panel gap, so that when I push the snow
(pretty much as DanS26 described), I will only need to push half as much, half as far, to the
nearest gap. Only 2 wires now cross each gap to the upper panels now, each securely tied
to a main support. Needed a couple short MC4 "extension cords" to do the extra distance.
Bruce Roe

[SunEagle]

Winter is here.

Bruce

Based on the weather forecast you may have to use your snow sweeper this weekend.

[bcroe]

Well I repaired my Fronius 7.5 yesterday.

Replaced the display board that is mounted on the door. Fronius tech support said the problem is definitely at the ribbon connection on the door side of the display panel. There is little cobalt/steel? oblong ring situated right at that connection. Fronius is aware of the problem...even had one of their factory mounted inverters with the same problem.

Bruce I suspect your problem is/was the same. It is intermittent and you may go months/years before it will appear again, but most likely it will appear sooner or later.

If you do replace the display board you have to make sure the brain board version matches the display version. Fix takes about twenty minutes all under warranty.

Good to know, thanks for the update. I think it won't be fixed before spring, but may run this
by my installer. Bruce

[DanS26]

Probably my problem isn't your problem. I looked at the display cable on my 7.5, but nothing was loose
or burned. But wires should not be discolored from heat. Lets see what develops with your repair.
Bruce Roe

Well I repaired my Fronius 7.5 yesterday.

Replaced the display board that is mounted on the door. Fronius tech support said the problem is definitely at the ribbon connection on the door side of the display panel. There is little cobalt/steel? oblong ring situated right at that connection. Fronius is aware of the problem...even had one of their factory mounted inverters with the same problem.

Bruce I suspect your problem is/was the same. It is intermittent and you may go months/years before it will appear again, but most likely it will appear sooner or later.

If you do replace the display board you have to make sure the brain board version matches the display version. Fix takes about twenty minutes all under warranty.

[Mike90250]

Here's an illustration of "sun hours" (Image below) at my location, in mid November. I looked back through my logs to find a good day without much cloud cover, which makes a really messy chart.
Follow the blue line, as it is battery voltage, and as the sun comes up, it climbs just a bit, but about 3 hours after dawn, it really takes off as the sun lines up on the array. Even a 1Kw load (red line) when my pump comes on, barely twitches the volts. Then about 3pm, it starts to crash as the sun drops off (note - this is a NiFe bank, not a lead acid)SunHoursExample.jpg

[J.P.M.]

I just got panels a week ago, so I haven't gone through my first winter yet.

My installer implied that the panels naturally shed the snow, presumably between the smooth glass and the dark profile. Is this generally not the case?

Maybe yes, maybe no. It depends. sometimes snow will slide of, sometimes not. Beware of snow slides.