Solar Array Mount Using Kee-Klamps

[Zeigh]

Hello,

Has anyone used Kee-Klamps to erect a ground mount solar array frame? Here is one example of a project:

http://www.simplifiedbuilding.com/projects/how-to-build-a-solar-panel-frame/

I have used this hardware in the past with other goals, so I am impressed with it's ease of application and strength. The projected cost of going this route is about half of a commercially available solar array mounting system. Of course, it would take longer to build and I would have to customize every cut and hole, which is why I understand that this is not a viable option for solar installers. Still, I am interested in any feedback from those that have used this type of design.


Peace,
Dr. Z.

[SunEagle]

Hello,

Has anyone used Kee-Klamps to erect a ground mount solar array frame? Here is one example of a project:

http://www.simplifiedbuilding.com/projects/how-to-build-a-solar-panel-frame/

I have used this hardware in the past with other goals, so I am impressed with it's ease of application and strength. The projected cost of going this route is about half of a commercially available solar array mounting system. Of course, it would take longer to build and I would have to customize every cut and hole, which is why I understand that this is not a viable option for solar installers. Still, I am interested in any feedback from those that have used this type of design.


Peace,
Dr. Z.

I don't know if it is the same hardware but I have seen similar ground mount solar frame at Carson City High School. Here is one picture of part of the array.

Carson City solar array 2013-01-15.jpg

[J.P.M.]

I don't know if it is the same hardware but I have seen similar ground mount solar frame at Carson City High School. Here is one picture of part of the array.

[ATTACH=CONFIG]6098[/ATTACH]

The members are pipe/tubing and the rest are avail. at big box in the chain link fence dept. Probably suitable for ground mounts with respect to strength. I'm not sure how cost effective given all the considerations necessary. Probably as good as most.

[SunEagle]

The members are pipe/tubing and the rest are avail. at big box in the chain link fence dept. Probably suitable for ground mounts with respect to strength. I'm not sure how cost effective given all the considerations necessary. Probably as good as most.

The system in Carson City was pretty impressive since it covered almost 5 acres. Total DC wattage was just over 1MW using 2 500kw inverters.

[J.P.M.]

The system in Carson City was pretty impressive since it covered almost 5 acres. Total DC wattage was just over 1MW using 2 500kw inverters.

That's actually relatively small for a non residential array by current standards. There's a 1.2MW array about a mile NE of my office door in the middle of what used to be an avocado orchard.

[bcroe]

Hello,

Has anyone used Kee-Klamps to erect a ground mount solar array frame? Here is one example of a project:

http://www.simplifiedbuilding.com/projects/how-to-build-a-solar-panel-frame/

I have used this hardware in the past with other goals, so I am impressed with it's ease of application and strength. The projected cost of going this route is about half of a commercially available solar array mounting system. Of course, it would take longer to build and I would have to customize every cut and hole, which is why I understand that this is not a viable option for solar installers. Still, I am interested in any feedback from those that have used this type of design. Peace Dr. Z.

That's cool. What foundation is used to assure it can't be lifted by the wind? Bruce Roe

[Zeigh]

That's cool. What foundation is used to assure it can't be lifted by the wind? Bruce Roe

I have seen various photos of designs that just have the round footers for each support pole. A few commercial solar array frames in my neighborhood are anchored in the same way. The question remains how much of a dance with my County building department there will be to get such a project approved. That is probably another reason that there aren't many custom mounts like this, as manufacturers like IronRidge provide the plans, specs, and more in their purchase package.

Still, I am already designing my own plans in a CAD program (Kee-Klamps even provides the digital components for such drawings). Hopefully an engineer will not be required for a permit.


Peace,
Dr. Z.

[peakbagger]

I have used key clamp type connections over the years on various industrial projects. They are quick and cheap but inevitably in areas where there is vibration, the clamps loosen up. If a project is in a low wind area they may be acceptable, but in high wind area there is constant vibration on the structure. I would be concerned that over the life of the project that unless there was routine checking of the torques on the clamps that eventually they would loosen up. In compressive loading its not an issue but in any joints exposed to tension (like cross bracing), I would be concerned.

[SunEagle]

That's actually relatively small for a non residential array by current standards. There's a 1.2MW array about a mile NE of my office door in the middle of what used to be an avocado orchard.

I have seen the array you are talking about on Google earth.

You might be right about the 1MW size as being small but it was the largest I have had hands on inspection and I thought it was big since the power will only be used by the High School.

[SunEagle]

That's cool. What foundation is used to assure it can't be lifted by the wind? Bruce Roe

Bruce

They used round concrete footers for this array. Here are a couple more pictures of the installation.

CCHS solar array 2013-01-15.jpgCCHS solar array pic2 2013-01-15.jpg

[bcroe]

Bruce They used round concrete footers for this array.
Here are a couple more pictures of the installation.

Thanks; then the question would be what dia and how deep? Here there is a footing
about 40" down, and a 12" column on that. Zoned AG here in the Wild West, no
inspections or permits req'd by the county.

Looks like no chance of tilting that design, but maybe that version could be designed.
Wonder what the vertical channels mounting the panels are, don't look like fence?

Loosening bolts could be made extra long to put on double or even triple nuts
that will never loosen, and then there is also Lock Tite.

Wonder if they have to clear snow off? Bruce Roe

[J.P.M.]

I have seen the array you are talking about on Google earth.

You might be right about the 1MW size as being small but it was the largest I have had hands on inspection and I thought it was big since the power will only be used by the High School.

Actually, the power is sold to the local water district by the array owners (SPP, Mill Valley, CA), and used to supply about 20% +/- a bit of the power for the pumps pulling water out of the reservoir just south of the array. Excess generation feeds to SDG & E. Interestingly perhaps, I rarely see any human activity, and the project seems to be meeting production goals without much cleaning or maint. that I can see/observe. My guess is they built in about 10-12% fouling allowance to the design.

[SunEagle]

Thanks; then the question would be what dia and how deep? Here there is a footing
about 40" down, and a 12" column on that. Zoned AG here in the Wild West, no
inspections or permits req'd by the county.

Looks like no chance of tilting that design, but maybe that version could be designed.
Wonder what the vertical channels mounting the panels are, don't look like fence?

Loosening bolts could be made extra long to put on double or even triple nuts
that will never loosen, and then there is also Lock Tite.

Wonder if they have to clear snow off? Bruce Roe

No the racking is pretty permanently fixed.

The vertical channels looked like they are made out of aluminum H frame of some kind. Here is another picture where the DC wiring goes into one of the 12 combiner boxes (each with 29 panel "strings").

CCHS solar array pic3 2013-01-15.jpg

I do not believe that have any formal procedure to remove the snow but what I saw is that it does eventually slide off.

[Zeigh]

I have used key clamp type connections over the years on various industrial projects. They are quick and cheap but inevitably in areas where there is vibration, the clamps loosen up. If a project is in a low wind area they may be acceptable, but in high wind area there is constant vibration on the structure. I would be concerned that over the life of the project that unless there was routine checking of the torques on the clamps that eventually they would loosen up. In compressive loading its not an issue but in any joints exposed to tension (like cross bracing), I would be concerned.

This is a good point that I asked the manufacturer about early on. They simply mentioned a few hundred feet of railing held together with their product that has been installed since the 1950's at a Niagara Falls lookout platform. Constant water spray, heat/cold expansion, thousands of tourists tugging on the bars, and the structure is still safe. Granted, the railings are not a virtual aircraft wing trying to take flight in high winds like solar panels might be, but a great endorsement nonetheless.

As an added peace of mind, I would erect my solar array frame and tweak all the fittings just right first, then systematically go through applying Loctite to each fitting.


Peace,
Dr. Z.

[J.P.M.]

This is a good point that I asked the manufacturer about early on. They simply mentioned a few hundred feet of railing held together with their product that has been installed since the 1950's at a Niagara Falls lookout platform. Constant water spray, heat/cold expansion, thousands of tourists tugging on the bars, and the structure is still safe. Granted, the railings are not a virtual aircraft wing trying to take flight in high winds like solar panels might be, but a great endorsement nonetheless.

As an added peace of mind, I would erect my solar array frame and tweak all the fittings just right first, then systematically go through applying Loctite to each fitting.


Peace,
Dr. Z.

Usually, most any set of design considerations can be accommodated if known. In this case, design of connections and other components that are assumed fixed can be made secure to the required degree for the imposed conditions by appropriate and adequate engineering.