Single-Axis East-West Sun Tracking Ground Mount Design

[Fearless]

I'm attempting to design a single-axis east-west sun-tracking ground mount. I know it's better to just add more panels. I still want to pull this off. I'll be using a simple reliable slew drive and a $50 controller that monitors the wind strength and levels when high wind is detected. I'm using 32 Bluesun BSM550M10-72HBD (https://www.bluesunpv.com/uploadfile/downloads/BSM550M10-72HBD-USA.pdf) divided into 2 arrays. I'm utilizing 2 1/4" 14 gauge galvanized square tubing for the solar panel mounting frame. The panel frame will be mounted on what looks like the pipe that holds up a see-saw. The post pipes will be 5 - 4 1/2" OD galvanized hexagon pipe. The horizontal turning pipe will be a 2" OD pipe.

I'm brand new to this so any tips are much appreciated.

Thanks,

Greg

 

[Fearless]

Working on new design.

 

[KITROBASKIN]

Hopefully you will provide images as your project evolves!

 

[Fearless]

Hopefully you will provide images as your project evolves!

Yes of course.

 

[Fearless]

Changed

 

[Fearless]

These mounting brackets might be better. With these, the panels will be pressed to the 2 1/4" square tubing. I would use my own bolt to fasten to the 2 1/4" square tubing. https://www.amazon.com/Zhengmy-Aluminum-Mounting-Brackets-Adjustable/dp/B0BGR2H6DC

 

[400bird]

I'm also working on a tracker, just because.

I expected a central bar/pivot point to act as the axis for your slew drive to pivot the array. How are the pillow blocks and sleep drive going to mount to the frame?

What size slew drive are you going with?

I'm just going simple and bolting the panels straight to the frame.

 

[Fearless]

I'm also working on a tracker, just because.

I expected a central bar/pivot point to act as the axis for your slew drive to pivot the array. How are the pillow blocks and sleep drive going to mount to the frame?

What size slew drive are you going with?

I'm just going simple and bolting the panels straight to the frame.

Something like this.


Slew Drive:
Rated Output Torque=6300N.m

Holding Torque=45Kn.m

The pillow block bearings mount to 4 of the poles. The 2" pipe turns in them.

 

[Fearless]

Old design updated.

 

[Fearless]

More planning. After wrong answers from AI bots for distances, I figured them out myself. I'm having a hard time figuring out how far apart the rows of arrays should be. I also picked up 36 of the 2 1/4" square tubing for the frames today.

 

[pvgirl]

This article goes in to the math for inter row spacing: https://www.greentechrenewables.com/article/determining-module-inter-row-spacing along with data from here(link seems to be wrong in the article): http://solardata.uoregon.edu/SunChartProgram.php

 

[Fearless]

This article goes in to the math for inter row spacing: https://www.greentechrenewables.com/article/determining-module-inter-row-spacing along with data from here(link seems to be wrong in the article): http://solardata.uoregon.edu/SunChartProgram.php

Thanks. Yeah, I found that site and if I tried working with formulas my results would be more wrong than the AI bots I was feeding. I was not successful in finding a tool where I could feed it my numbers to get the answer. I did find a 2X height suggestion.

 

[400bird]

There's no perfect spacing, at some point, no matter how far away, the sun side array will shade the next one over.

You need to figure out how late in the evening/early in the morning, the shade is ok.

Some max tilt numbers:
Maybe when the sun is at 20°?
That would make the spacing ~40' between rows to remove all shading.
30°? ~24' between rows
40°? ~16' between rows

Maybe your ok with shading the bottom row for some portion of the morning? You could cut out half the width of your array.

 

[Fearless]

There's no perfect spacing, at some point, no matter how far away, the sun side array will shade the next one over.

Yes, I found that out this morning. I stood where I my first array would go and my shadow was about 50 yards.

 

[PWH]

More planning. After wrong answers from AI bots for distances, I figured them out myself. I'm having a hard time figuring out how far apart the rows of arrays should be. I also picked up 36 of the 2 1/4" square tubing for the frames today.

View attachment 171102

I would highly recommend using SketchUp to layout your arrays and calculate inter-row spacing. You can geo-locate your design and then SketchUp will calculate shadows for any day/time you select. Has really helped me plan out my 3 tracking arrays. Oh and just use the 30 day trial which is free if you don't need a yearly subscription.

 

[Fearless]

Thanks to the city of College Station. Switching to 2 of these.

 

[Fearless]

Do I need one of these? https://www.amazon.com/Pikasola-Combiner-Lightning-Breaker，Combiner-Resistant/dp/B0BYZ9BLR5

 

[400bird]

Do I need one of these? https://www.amazon.com/Pikasola-Combiner-Lightning-Breaker，Combiner-Resistant/dp/B0BYZ9BLR5

Depends on your string layout and charge controller. Two strings and two MPPTs, no need for a combiner.

What's your string layout and charge controller?

 

[pvgirl]

Do I need one of these? https://www.amazon.com/Pikasola-Combiner-Lightning-Breaker，Combiner-Resistant/dp/B0BYZ9BLR5

If you are using those panels with the 18kpv inverter, then you don't need a combiner. 4 strings of 8 panels in series, can be wired directly to the 18kpv MPPT inputs. you want a disconnect where the PV circuits enter a building, like the IMO DC Solar Isolator SI32-PEL64R-8 4 String 32A

 

[Hedges]

I think it is preferable to avoid rows shading each other.
How about starting with all panels horizontal as sun appears on the horizon.
As sun rises, only tilt toward it to the extent you can without causing shade.
Similar after tilting toward afternoon sun - reduce tilt as needed to prevent shading.

Some PV panels are designed so shade on edge doesn't affect other cells. They are internally 72s6p or something like that, e.g. SunPower P17. But conventional panels with all cells wired in a serpentine, or half-cut, edge shading kills (1/3 or half) of production.

I think single-axis tracker would be great for a Southern facing hillside.