ground mounting options/questions

[garybeck]

(by the way i'm new here and I really appreciate this forum. thanks to those who answer questions... i have quite a bit of experience in solar and I'll definitely put my time in too)

i am putting together a system that requires a ground mount.

A seasonal adjustment of tilt angle will give up to 15% output year round, so you'd think that most of the ground mounts would have this option

but i can't seem to find any that are made to hold these new bigger panels and also have adjustable tilt angle.

Unirac's Solar Mount Tilt doesn't have adjustments.
DPW's adjustable mounts are only for the smaller solar panels.
Prosolar's aren't adjustable.

So then I look at top of pole mounts, which are adjustable. But only because you can loosen the ubolt that is holding the structure to the pole, adjust, and retighten. I think after making seasonal adjustments the nuts and ubolts will wear out, and that ubolt is the main thing holding the panels in position on a round object. (think how much easier it is to hold a square object in position than it is a round object). after a while it's going to be hard to tighten it as much. then when a 50 mph wind comes I'd start to worry about my panels.

DPW also has the multi-pole mounts which seem kind of cool (less stress on each pole/ubolt) but it's the still the same thing with the ubolts.

So I guess people just don't do seasonal adjustments anymore, now that the arrays have gotten a little larger? kind of sad...

So a couple questions...

are there any adjustable ground mounts I'm missing that can handle a dozen or 16 200W panels?

and

if I spec a top of pole mount, are people really loosening and tightening that ubolt all the time and not compromising the strenght of the connection?

thanks
gary a.k.a. the solar bus guy

[Vern2]

I'm using Unirac on flat surface.

Will this work? You have to mount lateral bars to cement post. The tilt legs are placed has offen as total weight of panels required. You tilt maybe up to 10 panels at once. This is a continues bar. It does not matter how big your panels are. The mounting points slide along mounting bars.



My own opinion is pole mounts take up too much room. They cast a very large shadow. Flat ground mounting uses 7 feet between panels, I'm talking 5 foot tall panels at about 33 degrees in winter for me Arizona, USA.

This is my project for my home. http://www.enichesoftware.com/solar/index.htm
I'm using 8 tilt arrays, 5 panels in each array.

Vern

[SolarGreenGirl]

UniRac now makes the U-LA racking for ground mounts and they will design the racking system for you on their website here is the link

http://unirac.com/equestionnaire.php?from_estimator=true

if you have problems they are very responsive on the telephone. The U-LA is for larger systems that are ground mounted.

[lile001]

(by the way i'm new here and I really appreciate this forum. thanks to those who answer questions... i have quite a bit of experience in solar and I'll definitely put my time in too)

i am putting together a system that requires a ground mount.

A seasonal adjustment of tilt angle will give up to 15% output year round, so you'd think that most of the ground mounts would have this option

So I guess people just don't do seasonal adjustments anymore, now that the arrays have gotten a little larger? kind of sad...


thanks
gary a.k.a. the solar bus guy

There are some other variables that have led me to do a fixed mount. Here, especially this winter, we get little sun. We went 30 days without a full day of sun, 45 days without three full sunny days. Typically November is cloudy the month through. So point your array in the winter anywhere you want, you won't get much out of it around here! In the summer, your latitude is not the ideal angle - less of an angle is better. Here, we get long weeks of no clouds in the summer. The rates that I get for the feed-in tarrif are higher in the summer. I calculate using PVWATTS that a 19 degree fixed mount is $8 a year less income than a 38 degree fixed mount. That is the same as ten sunny days on a 4 KW array with my local rates. It's in the noise.

20 degrees or so tilt (4:12 roof) maximizes summer sun at my latitude. If you are in an area with a cloudy winter, you are just as well off with a fixed mount at a reasonable angle. Build yourself a solar-roofed gazebo in the front yard and enjoy it in the summertime, when your production maximizes!

I have tiltable mounts on my solar water heater. There is a hinge at the bottom, and four aluminum legs at the top, with three different holes drilled at summer, mid-year and winter positions. I hacked these onto the standard mounts that came with the collectors with some angle iron and stainless bolts. nothing can wear out that can't be easily replaced. This is an assembly that is maybe eight feet long, and one guy can change it.

My solar array is planned at 30 feet long and 12 feet wide. That's a whole nuther animal! Moving a large solar array is a big chore, building the moveable racks add hundreds or even thousands to the cost of the mounting! I backed off of a moveable solar electric array and I'd advise the same.

[BadgerBoy]

I was frustrated looking for a seasonally adjusted mount also, so I built my own out of Super-Strut. I'll post pictures if anyone is interested yet on this thread. My mounts hold 6 large panels and the mount is from a design in Home Power magazine.