Oh duh!
Perfect sense now that you've spelled it out for me ;-)
How high are you thinking you'll put the panels above the roof and what's going above the S-5s (i.e., what are using to get the elevation above the S5)?
I'll probably go S-5 rib mounts and some Iron Ridge rails, (unless all you wiser than I have suggestions, I'm totally open). They won’t be flat,I’ll throw some tilt on them to get as much reflectivity on the back side as I can.
The
S-5 Rib mounts you linked look tough, but the metal gauge of the roof usually isn't all that thick, you might also want something like we use here for "
hurricane strapping" to help keep the roof on.
Wind forces on elevated sources are huge. My panels are flat and I take a fairly big hit from hit from it. But the wind forces with even a few inches elevation would be the equivalent of a herd of elephants on my roof (several tons). But, codes here are for 180 mph winds.
I started from the
basics document, but if you look at example 2 it's for 90 mph winds with panels parallel to the roof which is the best case to minimize wind forces:
When you work through the math they come up with:
So, for 90 mph, that's an uplift pressure of about 23 psf and downward pressure of about 15 psf for zone 2 (
explanation of zones), as you can see they get a whole lot worse near the top and corners.
The LG Neon2 bifacials are 18.44 ft², so 12 of them would be ~222 ft² (if my calculator is right). so 222 x 15 = 3320 lbs downward force and 5110 lbs uplift. Have a steeper roof? More force. Add tilt, more force.
Hope that helps!