Panel Array +Support Structure questions

[oldryder1973]

ground mount. Looking at pics many of the designs have support members running under and parallel to each side frame of the panels. Other merely have support elements running at right angles to the panel frames which makes for a far simpler structure. support elements paralleling the panel frames seems redundant.

what am I missing?

 

[MichaelK]

what am I missing?

Wind! The panels act as sails, catching many footpounds of force from every square foot of space. I've seen posters talking about their array frames, and my observation was that they looked far lighter/simpler than my design. When they check back in the next spring, they talk about how all their panels shattered because of wind-stresses.

I designed my frames looking at the frames the highway engineers put up for over-the-road signage. Lots of trusses and three-dimensional re-enforcement. I try to duplicate those things in my design. Here's a pic of my ground mount, which is both daily, and seasonally adjustable. It can hold as many as 6-250W grid-tie panels. It's made primarily out of 1-5/8" unistruts that are welded together.

BTW, I made the frames for my very first 12V system out of sheet-rock edging. The stuff is so flimsy that you can tie it in a knot with your hands. But, I made sturdy frames that have survived for 8 years now by placing trusses at 45 degree angles every 8" or so. I decommisioned my 12V system years ago; I guess it's time to go up on the roof and remove them.

 

[schmism]

You can find photos of the ground mount I built in my build thread.