Earth tilt and array alignment

sarossell

Solar Enthusiast
Joined
Apr 12, 2021
Messages
39
Here in Arizona, we all know panels face South and tilt perpendicular to Sun depending on the time of year. Most just either go flat and lose about 15% of the potential power or go with a stationary 35° because they need the most power during the Summer months and can't afford to use tracking or adjustable arrays.

BUT, what about orientation to the real Earth-tilt path of the sun? The planet tilts roughly 23°, so the arch of the sun facing South is actually more like South-East to North-West than actual true East to West, correct? If so, would it make sense then to angle the entire array 23° off-compass so it's facing the full arch of the sun?

And if true, would it really make all that much difference?
23 Degrees.png
 

Diysolar123

Photon Sorcerer
Joined
Feb 28, 2021
Messages
667
if you are really worried about it you could just get solar tracking circuit, or a diy solar pointer...along with linear actuators.
diy solar pointer would be about $10, and linear actuators are maybe $30 each
So thats $40 for one axis and if you want two axis tracking...$70 total??

you can buy really fancy solar tracking kits, or just use the automotive heavy duty linear actuators, durable and cheap hehe
 

Northernchateau

Solar Enthusiast
Joined
Apr 14, 2021
Messages
195
Location
Worth, NY
Funny you ask that question.
Today I set up a test stand with a single 175Watt panel which is adjustable from horizontal to vertical and on my trailer so I can rotate it perfectly inline to 180 deg out. It's connected thru a volt, amp watt meter to a charge controller, batteries and inverter.
The next clear sunny date I plan on taking a lot of reading then put them on a spread sheet and share here with the group.
I also have a 4'x8' sheet of foil faced insulation board as I want to see the effect of reflected sun on that panel.
 

sarossell

Solar Enthusiast
Joined
Apr 12, 2021
Messages
39
But what if the array is 10 feet tall, 32 feet long, and weighs nearly a ton? For tracking, I would have to group the panels by weight and then spread them out to avoid overshadowing. Each panel weighs 62 pounds.
 

sarossell

Solar Enthusiast
Joined
Apr 12, 2021
Messages
39
Funny you ask that question.
Today I set up a test stand with a single 175Watt panel which is adjustable from horizontal to vertical and on my trailer so I can rotate it perfectly inline to 180 deg out. It's connected thru a volt, amp watt meter to a charge controller, batteries and inverter.
The next clear sunny date I plan on taking a lot of reading then put them on a spread sheet and share here with the group.
I also have a 4'x8' sheet of foil faced insulation board as I want to see the effect of reflected sun on that panel.
I admire your experimental spirit. Best of luck! Looking forward to seeing your results.
 

pollenface

Solar Addict
Joined
Nov 14, 2020
Messages
521
Location
Perth, Australia
I've thought of setting up a single axis tracker with only "tilt" using linear actuators and separate panels to power the actuators

The "tracker" panels would have to be positioned at an angle to each other. As the sun rises or lowers in the sky, the "tracker" panels would constantly cause the actuators to move in a way that the power stays equal in both tracker panels to cancel each other out (each wired oppositely to the actuators).

When it has to withstand the occasional 100kph/60mph wind, things get complicated.

here's where i got the idea
 
Last edited:
  • Like
Reactions: reg

Northernchateau

Solar Enthusiast
Joined
Apr 14, 2021
Messages
195
Location
Worth, NY
Depending on where you live there can be a few things to consider with a tracking system.
Wind, Snow and Ice or a combination of all 3....
 

Diysolar123

Photon Sorcerer
Joined
Feb 28, 2021
Messages
667
Depending on where you live there can be a few things to consider with a tracking system.
Wind, Snow and Ice or a combination of all 3....
the failure point of the panels is much lower than the failure point of even low cost linear actuators...
The weak point would be the mounting frame and panels; basically design a frame that always takes the load and the panel just sits on the frame.
tig/mig weld some 1x1 1/8" thick square tubular steel...the panel will shatter before the frame goes with a panel.
Now as you increase the area of the solar panels you will need to increase the strength of the frame.
When it comes to the rare very high windspeeds, you take down things that can be damaged.

here is a video of hurricane force winds on solar panels just using structural pipes hehe

as to the angle, even if you do NOT use an automated system if its easy to adjust, you can just change you angles monthly so you always have the best "seasonal" angle.
A solar tracker will produce more power than a static setup UNLESS if you live in a very cloudy area.
solar trackers get all their advantages in the morning and late afternoon...if it tends to be cloudy then, well, its useless hehe'
 

reg

Winter: New York City Summer: Atlantic Canada
Joined
Mar 24, 2021
Messages
338
Does anyone have a rough idea of how much draw a solar tracker would require for a single residential panel made by a company like LG or Panasonic? By residential panel, I mean one about 1.7m x 1m (66" x 40"), weighing about 18kg (40lb).
 
Last edited:

Diysolar123

Photon Sorcerer
Joined
Feb 28, 2021
Messages
667
Does anyone have a rough idea of how much draw a solar tracker would require for a single residential panel made by a company like LG or Panasonic? By residential panel, I mean one about 1.7m x 1m (66" x 40"), weighing about 18kg (40lb).
the draw of the solar tracker is completely dependent on how you build it...the weight of the panel is not the deciding factor at all, if well balanced it will take little force to move. It the mechanical design that drives the forces (and therefore motor size) needed on the screw/linear actuator.
Also solar trackers never need to move fast, the software will usually start to slew to the morning position once it has decided night has arrived so it can go nice and slow hehe

Think about a balanced gate, you can swing a 200lb gate open with your little finger.
 
  • Like
Reactions: reg
D

Deleted member 23531

Guest
I haven't delved into the geometry @sarossell but I think your suspicions might be wrong. The planet may tilt 23 degrees off of "vertical" (in an elementry school science fair sense of "vertical"), but that is a "yaw" adjustment if your panels are pointing at the sun, so it makes no difference I think.

In other words, if you have the optimum elevation angle (for the current season), your panels are perpendicular to the sun's rays, at noon, let's say. Then the 23 degrees of planet tilt is a rotation of the panels about this normal axis. Just spitballing here, but that's my sense of the geometry you're talking about.
 
Last edited by a moderator:

Hedges

I See Electromagnetic Fields!
Joined
Mar 28, 2020
Messages
9,323
Rather than a motorized tracker, I think an array aimed South East and another aimed South West, wired in parallel to the MPPT, is a better way to go.
Extra panels are cheaper than a tracker for the watts they produce. Multiple orientation strings into an MPPT has about 2% penalty over individual MPPT in terms of production, and you can put about 40% more watts worth of panels on the MPPT this way (assuming 90 degree angle between the arrays.)
 
D

Deleted member 23531

Guest
I haven't independently verified this website's numbers, but they say:

1619490865483.png


So even if you had discovered some planet-geometry fact that everyone else on the planet had overlooked (which I doubt), it would only yield you a few percent. The real gain is to be had by tracking throughout the day, or, as @Hedges mentioned, you can emulate that by just pointing some panels eastward and some westward instead of all of them due south.
 

NPhil

Freezing in the dark non-enthusiast
Joined
Apr 23, 2021
Messages
144
if you are really worried about it you could just get solar tracking circuit, or a diy solar pointer...along with linear actuators.
diy solar pointer would be about $10, and linear actuators are maybe $30 each
So thats $40 for one axis and if you want two axis tracking...$70 total??

you can buy really fancy solar tracking kits, or just use the automotive heavy duty linear actuators, durable and cheap hehe
That does make a lot of sense, but, I have a couple of questions:

1. Can you point me to an actuator which can handle 250 lbs. of array (I just got around to estimating), and has a manual crank (so I can turn it with a wrench or something, should a perfect storm occur)?

2. Wouldn't it make sense to adjust the azimuth manually (at weekly, or even longer, intervals) and only do powered tracking on one axis?
 
Last edited:

Skysthelimit

New Member
Joined
Dec 25, 2019
Messages
58
Location
Cedar City UT
Here in Arizona, we all know panels face South and tilt perpendicular to Sun depending on the time of year. Most just either go flat and lose about 15% of the potential power or go with a stationary 35° because they need the most power during the Summer months and can't afford to use tracking or adjustable arrays.

BUT, what about orientation to the real Earth-tilt path of the sun? The planet tilts roughly 23°, so the arch of the sun facing South is actually more like South-East to North-West than actual true East to West, correct? If so, would it make sense then to angle the entire array 23° off-compass so it's facing the full arch of the sun?

And if true, would it really make all that much difference?
View attachment 46707
Thanks for posting this question. I too am interested in the correct azimuth heading to orient my array to. I read most of the replies to your question, but there was a lot of rabbit trails that didn't help. What did you end of setting your array to? I'm getting ready to start erecting the ground mount for my 32 panel array (4 strings of 8 in landscape orientation) this week and need to nail down the orientation as my 10 3" galvanized poles will be set in concrete so when it's done, it's done. Please let me know what you decided. George
 
Top