Determining the Wind Rating for a DIY Solar Ground Mount

[OrlandoSolarBears]

Hey Guys!

I'm constructing a ground mount for my solar panel that is similar to the one found in the video. While putting the system in pretty straightforward, I still live in Florida, so I want to be reasonably sure that the system can withstand some of the weather that we get here. The system is not a grid tie-in, nor does it need to signed off by PE; but I would still like to know what kind of wind rating my system will have (I would like for the system to be able to withstand at least 150 MPH winds). I have an undergraduate degree in Mechanical Engineering, but it's been awhile since I've worked with any structural equations. Do you guys have any recommendations on how to proceed?

[posplayr]

Hey Guys!

I'm constructing a ground mount for my solar panel that is similar to the one found in the video. While putting the system in pretty straightforward, I still live in Florida, so I want to be reasonably sure that the system can withstand some of the weather that we get here. The system is not a grid tie-in, nor does it need to signed off by PE; but I would still like to know what kind of wind rating my system will have (I would like for the system to be able to withstand at least 150 MPH winds). I have an undergraduate degree in Mechanical Engineering, but it's been awhile since I've worked with any structural equations. Do you guys have any recommendations on how to proceed?

You need a refresher, but this something I recently did as well despite being an EE.

There are standards for winds depending on local. In Florida you are in a hurricane prone zone so wind speeds are higher. If you compute dynamic pressure of the air at the velocity and density you will get lbs/ft^2. 90 mph is about 25 lbs/ft^2 You can figure (150/90)^2*25 is the loading you will be looking at for 150 mph. Q=1/2 rho V^2

Here are some document titles you can goole; I recently downloaded them.

• ASCE 7-10 Wind Provisions and Effects on Wood Design and Construction
• Jim Dunlop Solar Chapter 10 mechanical Integration.

The are ME calculators on the web for computing uniform loads of supported and cantilevered beams. The refresher will do you good.

If you have a friend wit ha PE license you can have them go over your calculations and of course if you need a permit you will likely need a PE stamp.

[J.P.M.]

Hey Guys!

I'm constructing a ground mount for my solar panel that is similar to the one found in the video. While putting the system in pretty straightforward, I still live in Florida, so I want to be reasonably sure that the system can withstand some of the weather that we get here. The system is not a grid tie-in, nor does it need to signed off by PE; but I would still like to know what kind of wind rating my system will have (I would like for the system to be able to withstand at least 150 MPH winds). I have an undergraduate degree in Mechanical Engineering, but it's been awhile since I've worked with any structural equations. Do you guys have any recommendations on how to proceed?

See: "Wind Load Calculations for PV Arrays", Stephen Barkaski, P.E, and Colleen O'Brien, P.E.

The usual std. is ASCE 7-05. The above provides some background. If you've used 7-05 as an engineer, you know the drill. Ground mounting will be somewhat different and involve foundation design and soil considerations.

[posplayr]

BTW, don't copy that guys design. His weak points are the pivots which gets down to sheer stresses on single bolts.