Sun hours

[Mike90250]

One of the few remaining phone booths !

[SunEagle]

Very impressive Bruce. I wish you well with that new panel tilting system.

[bcroe]

Its up, a 24 panel tilting array. The original PV array here was a classic SW desert system, which was FAR
from optimized for northern IL operation. After 4 years of observations and measurements, the new design
is an attempt to correct a number of problems.

The newest array is accurately positioned, and located to avoid previous shadows all day long. Physical
accuracy of the array itself is high. It mounts 24 panels of 250 watt rating, or 6KW.

Observations over days and seasons have been made, including with test panels. This input has been
used to attempt to maximum summer hour production over the entire day. This will be somewhat less
effective for other seasons, but variable tilt will allow some compensation. Existing arrays will be working
with this one.

The array is 12 panels wide and only 2 panels high, landscape orientation. This will greatly aid in allowing
easy tilt adjustment. An 8" gap between the upper and lower panels provides a space for snow to drop
through, combined with low height, to ease the labor of snow removal. Tilt bearings placed in the gap are
close to the center of gravity, minimizing tilt effort. 40" ground clearance minimizes or eliminates the need
to relocate snow piles from the panels. In case of a snow storm the array could easily be set to vertical, to
minimize snow pickup.

This array is designed to track the ground 10% slope along its length. No extra earth leveling, moving, or
"steps". The chain running across a picture was to keep my equipment from sliding down the hill while
working. The foundation contains 240' of rebar, with 6 pairs of front and rear supports joined 4' below
ground level to eliminate frost heave. Machine roller bearings can be greased.

I don't expect to change the tilt angle very often, though a couple of electric actuators are available. To
keep things steady the rest of the time, extra braces are bolted on at the bottom.

The wiring isn't on yet, hope I have enough to reach the 12 position combiner box nearly 200 feet away.
A 6 gauge ground wire runs with the panel wiring.

My considerable net metering reserve was useful this year. My well sprung an internal leak, causing
enough loss of pressure to run the motor continuously. I didn't realize it for weeks, my reserve is gone,
its all been renewed now. Net metering starts again on 1 April.

Bruce Roe24Rebar.JPG 24FouPosts.JPG
24FEast.JPG
24EndFr.JPG
24Rear.JPG
24ReSiSec.JPG
WellRepr.JPG

[Mike90250]

Thought I'd piggyback onto this. While doing irrigation research, came across this page of daily solar log for farming

http://www.cimis.water.ca.gov/SpatialData.aspx

Your state may have a like program.

[azdave]

I extrapolate that without a gap, I would have a lot of snow to move.

I hate to extrapolate snow. That's why I moved to Phoenix.

[bcroe]

Here a 6 inch gap has been added between the upper and lower
panels. Snow will only need to slide half as far to clear a panel, and there will be only half as much
snow being pushed into each pile on the ground. That means I won't be doing so much running the
snow blower to keep the pile lower than the bottom of any panels. And pushing snow off will be a
lot lighter work; possibly avoided completely on some occasions. This would work even better if
the panels were turned landscape. But that would be much more difficult, and will be postponed
to another phase. Bruce Roe

As the white stuff did its last Mon and Tues, the snow slots again proved their worth. This morning
panels with a 6 inch gap were already 97 % clear. The one test section with a 4 inch gap was only
about 60% clear. I extrapolate that without a gap, I would have a lot of snow to move. Bruce Roe

[SunEagle]

Sorry to hijack a thread, but how the heck do I post a new topic?

Apparently the Administrator or Senior Moderator must approve your ability to post a new topic. Since I am a minor Mod I can't do that for you but I ask for your patience and you will be able to make new posts soon.

[cnote]

Sorry to hijack a thread, but how the heck do I post a new topic?

[bcroe]

Progress on outdoor projects is kind of halting in Jan/Feb, but in some better weather I did get more
aluminum bolted in place on the 24 panel tilting array. Its horizontal, pointed straight up so I can
reach everything. But capable of tilting 90 degrees to straight up, should be great for a snow storm.

Still need to add a convenient tilting control and some back side bracing in the 3rd dimension, before
mounting panels. Bruce Roe

PVtilt1.JPG


PVtilt3.JPG

[bcroe]

I read your entire thread today, and would like to applaud your outside-the-box thinking. Your system may not represent the best value per dollar spent, but it is invaluable at showing the potential that can be realized if one doesn't constrain themselves to do things the way everyone else does just because "that's the way it's done." Optimum points are only eventually found because somebody pushes things to the llimit in a different direction and posts their results, as you are doing.

I'm working on an off-grid design in Missouri and also looking for a flatter curve but to maximize per dollar spent daily production. So what your doing is of some interest to me, although I unfortunately do not have the option of banking summer production for winter use, so I'm working on a much smaller scale.

Now take this with a grain of salt because I'm a newbie here and there is lots I don't know yet, but I wonder if your east-west IV curve (with no straight south facing panels) would be a flatter on top if your panels were facing slightly SE/SW instead of straight E/W. Idk, it might lessen output early/late on summer days when the sun actually rises/sets NE/NW of you, but it seems to me the increase on winter days when it better faces the rising/setting sun and in mid-morning/mid-afternoon in the summer would result in net gains without much noon-time clipping.

Thanks for the comments/questions, and good luck with your off grid design. Off grid of course requires a far greater
commitment of all resources, time and very high $ per KWH. Still an on going science project here, the right answers
in northern IL will not be exactly the same as in Missouri.

Off grid might flat out optimize winter production, summer is easy by comparison. Not as much so with net metering,
but the same idea could apply. Looking at my Solar Pathfinder at 42 deg Lat, it appears a straight E-W alignment is
a pretty good split of the sunrise/set angle between the longest and shortest days. Slightly favoring South is probably
better for off grid, you might run that experiment. The basic idea here has been to collect as much energy as possible
when the sun is not ideal, then change things enough to just stay in clipping any time the sun is good.

Yesterday was a sunny day, cranked out 93KWH from 15KW of inverters. Some would call that 6.2 sun hours, not
bad for early Feb here, impossible with a unidirectional array. Outdoor work will be mostly on hold here till the foot of
snow dropped last week goes away. Meanwhile looking at mini split heat pumps. Bruce Roe

[SupraLance]

I read your entire thread today, and would like to applaud your outside-the-box thinking. Your system may not represent the best value per dollar spent, but it is invaluable at showing the potential that can be realized if one doesn't constrain themselves to do things the way everyone else does just because "that's the way it's done." Optimum points are only eventually found because somebody pushes things to the llimit in a different direction and posts their results, as you are doing.

I'm working on an off-grid design in Missouri and also looking for a flatter curve but to maximize per dollar spent daily production. So what your doing is of some interest to me, although I unfortunately do not have the option of banking summer production for winter use, so I'm working on a much smaller scale.

Now take this with a grain of salt because I'm a newbie here and there is lots I don't know yet, but I wonder if your east-west IV curve (with no straight south facing panels) would be a flatter on top if your panels were facing slightly SE/SW instead of straight E/W. Idk, it might lessen output early/late on summer days when the sun actually rises/sets NE/NW of you, but it seems to me the increase on winter days when it better faces the rising/setting sun and in mid-morning/mid-afternoon in the summer would result in net gains without much noon-time clipping.

[bcroe]

Slow progress with seasonal events and the sub zero temps. But the tilting array pivots are built and
awaiting final alignment. The middle 4 bearings can be adjusted in one direction by sliding along the
mount surface, and in a perpendicular direction by slightly changing the attachment of the back tilt
braces. I expect nothing will move as far as 1/4 inch. After that, the tilting section for 24 panels can
be built up. Bruce Roe

We finally got hit with a real winter storm, a foot of snow forecast, half that fell at this location. The array
snow slots are just a lifesaver in clearing that stuff.

Up until now winter has been mild enough for some slow progress on the tilting array. The 6 bearings were
aligned well enough I could see a light through them all. Maybe 3/4 of the section pictured on the ground
above, is now mounted in the air, just above my head when tilted flat. So close, but until there is a big
improvement in the weather, completion will have to wait. Bruce Roe

[bcroe]

Slow progress with seasonal events and the sub zero temps. But the tilting array pivots are built and
awaiting final alignment. The middle 4 bearings can be adjusted in one direction by sliding along the
mount surface, and in a perpendicular direction by slightly changing the attachment of the back tilt
braces. I expect nothing will move as far as 1/4 inch. After that, the tilting section for 24 panels can
be built up. Bruce Roe

VPpiv1.JPGPVpiv2.JPGPVSep17tst.JPG

[bcroe]

Since I now have more than a couple of acres to play with it will be a
ground mount. I will probably be asking a lot more questions concerning what you did on your install.

Good, I still have plenty of questions here. Conditions are a lot different in FL. Bruce Roe

[SunEagle]

Oft decried, but a decent beginner learning tool, the Horrible Fright kit is now updated to 100W, on
sale for $1.50 a watt including a charge controller with readout and a couple lights for the 12V
battery you must add. Bruce Roe

After a break for required seasonal duties, am contemplating a design of the last primary component: the
pivot point connecting the fixed base to the pivoting 24 panel mount. Snow has been very late this year,
but now threatened. Bruce Roe

I have seen where HF have tried to step up their game by increasing the system to 100w. While the price per watt is much more reasonable I wonder what the life of those panels will be?

Back on topic.

Those are really nice support structures you have installed. Once the dust settles and I sell my old house I can focus on installing a pv system on the new homestead.

Since I now have more than a couple of acres to play with it will be a ground mount. I will probably be asking a lot more questions concerning what you did on your install.