Structural Design for Ground Mount

[mazgaon]

Hello,

I am working on with Town of South Windsor in Connecticut to get approval for my Ground mount system. I have the Zoning department visit and bless the location and everything seem to be going good until i was asked to submit a CT Engineer Certified Structural design for the EG4 BrighMount Ground Mount Kit.

The EG4 manufacturer had sent me their structural analysis and it seems it was for 105mph wind speed and CT needs 120 mph wind speed analysis but moreover signed by CT Certified Engineer.

I tried looking at Google but could not find any CT Certified Engineer for this job.... Any suggestion?

I tried GreenLancer and they quoted me $650 for signup.

Thanks,
Dinesh

 

[OzSolar]

IMHO, Greenlancer's price doesn't sound too bad. Hopefully this will bump your post and get you some answers.

To be honest I'm surprised the EG4 Brightmount passes a 105 MPH structural analysis. It looks to me like it wouldn't take much effort at all to snap off those bolts. And if they didn't fail, they'd break concrete they are mounted to. There's a lot of lever arm there, particularly on the high side.

That being said I suspect you may have a challenge getting a "traditional" structural engineer to sign off on it. Not saying it's bad product, in fact I think it's a great product for the price point it lands at. It will likely be fine in 99% of applications but engineers don't put thier stamps on things if they aren't 100%.

 

[mazgaon]

IMHO, Greenlancer's price doesn't sound too bad. Hopefully this will bump your post and get you some answers.

To be honest I'm surprised the EG4 Brightmount passes a 105 MPH structural analysis. It looks to me like it wouldn't take much effort at all to snap off those bolts. And if they didn't go they'd break concrete they are mounted to. There's a lot of lever arm there, particularly on the high side.

That being said I suspect you may have a challenge getting a "traditional" structural engineer to sign off on it. Not saying it's bad product, in fact I think it's a great product for the price point it lands at. It will likely be fine in 99% of applications but engineers don't put thier stamps on things if they aren't 100%.


View attachment 229741

Thanks OZSolar... Is there any other DIY friendly ground mount structure that is available in the market that could pass the Structure design.

What is the diameter of the concrete you lay out there.... The other challenge is the manual says it should be almost 20 inch wide... I could not find this big sonotube in HomeDepot or Lowes.

Thanks,
Dinesh

 

[Solar Guppy]

IronRIdge is the industry gold standard and has fully engineered options ( online design tools as well ) . You will almost always be required to get PE approval for plans when getting permits, not just the solar mounting, but whole system. Green Lancer is whom I used to get the plan's PE wet stamped.

 

[cdsolar]

Here is my AHJ approved Brightmount. I did not need stamped drawings, I only needed to adhere to the manufacturers' instructions. I replaced the blocks from the manual with 24 inch diameter sonotubes, 18" above ground as per instructions, and 36" below ground to frost depth. Was ready to show AHJ that the filled sonotubes were heavier than the blocks, but he didn't ask.

Post your Ground Mount Setup

About 4ft deep and 6 bags. Thats a 14ft pole, reused oilfield pipe. Right on. I'm guessing 6 x 60# bags of ready-mix? That reused oilfield pipe is the stuff. Saw some folks here n Alaska make a massive fence around their garden using some of that and what a great way to reuse metal.

diysolarforum.com

 

[OzSolar]

Thanks OZSolar... Is there any other DIY friendly ground mount structure that is available in the market that could pass the Structure design.

What is the diameter of the concrete you lay out there.... The other challenge is the manual says it should be almost 20 inch wide... I could not find this big sonotube in HomeDepot or Lowes.

Thanks,
Dinesh

Of course "DIY Friendly" can mean a lot of things to a lot of people. I'm getting ready to build a ~4kW skid mounted array that I drag around my place with a tractor depending on what I need from it. Most of the time it will be used for pumping water from a spare well on my property to a pond I'm expanding but I'm going to rely completely on it's on weight plus some ballast to keep it from flying away 99% of the time. No permits required in my area though.

You might try to go down the road of a "mobile" installation. There are people here who say they mounted thier solar panels on a bus, a trailer or shed with wheels on it therefore sidestepping the permanent install requirements. There's been some really creative ideas! Hopefully one of them will see this and chime in.

 

[rhino]

Thanks OZSolar... Is there any other DIY friendly ground mount structure that is available in the market that could pass the Structure design.

https://www.sinclair-designs.com/. Their standard design is rated for 125mph and you can get it stamped by engineer.

 

[Gttnsun]

Solar panels are basically a big wind sail, the concrete needs to be able to hold the panels down to the ground in big wind gusts. The eg4 brighmount paperwork is saying it will only hold 1 550w panel in 105 mph wind.
There are many companies that sell ground mount kits that have engineering paperwork included, pier depth and width depends on a few factors, panel size and quantity, angle, wind load snow load, and soil conditions.
I built a Tamarack Ground mount

Ground Mount System | Tamarack Solar Products

The Tamarack Ground Mount System allows you to build a simple, low-cost structure with columns of 3 or 4 modules in landscape orientation.

tamaracksolar.com