Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Solar Panels and Snow Load

Solar Panels and Snow Load

Solar Panels and Snow Load

Does anyone know of any literature that addresses snow loads and solar panels? Every time I confront the manufacturer of the panels they said they don't increase the snow load on the roof. It drives me crazy that this is never really addressed. Attached is a sample photo of a system my client wants to put on his roof. I find it hard to believe this type of system will not attract more snow because it would act like a "cheese grater". Not to mention this thing looks like it would put some concentrated loads on the roof.

RE: Solar Panels and Snow Load

Design Snow Loads for Solar Paneled Roofs
ASCE webinar by O'Rourke

RE: Solar Panels and Snow Load

That seminar is 4 months from now, I don't think my client will wait that long.

RE: Solar Panels and Snow Load

I've got this which is not exactly recent.

And there's this from a supplier: Link

These are good but deal with wind and seismic only:



I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

RE: Solar Panels and Snow Load

If you get a 6" snowfall, that's all the weight that there is whether you have solar panels or not. I`d agree with the manufacturer
Will it change the load distribution? Instead of an evenly distributed load, now it's being concentrated on the rails down each side.
Will it create drifts? I think this is where it gets a little tricky. I`d lean towards "yes" in any location where the array is greater than 15' wide.

RE: Solar Panels and Snow Load

There are quite a few reports out there from reputable firms such as RWDI that do confirm that in certain configurations and layouts that the design snow load is not affected. These are specific to racking manufacturers. I do not have any I can put my hands on or share at this point in time. Reputable solar racking manufacturers get reports completed for their systems that confirm design snow and wind pressure information that is useful to structural engineers. Whenever I have worked on a roof top solar project in the past, we require the solar manufacturers (typically the racking suppliers) snow/wind report for their system before we will start work on the project. If they cannot produce a report, we do not do the work. They grumble at getting the reports completed as they are quite expensive, however, it is just another cost of business that they need to account for if they are going to complete their projects properly.

Racking layout must be considered, as does ballast layout for ballasted systems. You are correct that the point loads and their effect on the loading the roof structure must be considered.

There are many, many engineers getting the snow/wind reports, accounting for point loads, etc.... so don't let the solar people tell you differently. I do find that there are solar companies that just keep calling around until they get the engineer that is willing to sign off cheaply, without reviewing any background info, nor requesting reports, likely due to unfamiliarity with the in's and out's of this type of work. I would not recommend being that engineer.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close