Panel Racking

[bcroe]

I have included this picture of my prototype racking. Of course, it is only one section and there will be many more pieces like this. I am looking to build a section that holds 9 horizontally mounted 250W panels. There would be a minimum of 12 concrete weights. Only 2 are shown. 4 ballast weights across and 3 deep supporting an array of 3 panels wide by 3 deep.

The wood 2X3 represents the short side of one of the 77" X 39" panels. Adjacent panels would share clamps in the horizontally run Unistrut. Greg

I don't see any triangle braces. That 4 sided figure could pivot or "rock" at the corners.
Bruce Roe

[gmcmurry]

Did you notice this was a DIY section? (smile)

All of your thoughts are appreciated and will be taken into consideration. There are many ballasted installations in my area, so this is nothing new. Its simply an engineering issue.

It is far safer, on a flat roof, to make no penetrations. When I say flat, I mean zero pitch. You must have roofs like that in San Diego.

As for insulation -- If 1/3 of your roof is covered by solar panels, that is 1/3 the amount of solar heat being absorbed by your roof. In my case, I have no insulation on my roof. My roof is simply hot mop, paper and gravel covered T&G 2X6s. I will definitely get an insulation benefit by installing solar panels. That much less heat through the roof, that much less air conditioning, that much more benefit from having roof mounted solar panels.

Greg

[J.P.M.]

I am working on a ballasted racking idea for my flat roof at 34 degrees in Southern California. It seems I have the perfect location for many many panels. My house gets really warm, as it is pounded by the sun. When this project is completed, I will even appreciate the extra insulation I will get by having a major portion of my roof double insulated by a layer of solar panels.

My current design will use a Unistrut frame mounted on concrete ballasts. Wind is not a problem in my area.

My question is (I am sure this is the first of many) if I am mounting my panels in "landscape" mode, is there any reason I cannot clamp them to my horizontally run Unistrut on the ends? This would be two conventional clamps on the short ends. My panels will be about 6' 5" X 3' 3". I would have the clamps about 28" apart on the 3' 3" (39") side.

Almost every illustration I have seen, shows panels attached on the long side when in "landscape" position.

I need most of my power in the Summer, I am thinking of 15 degree tilt, direct facing South and rows 24 inches apart.

I would appreciate any comment.

[ATTACH=CONFIG]4341[/ATTACH]

I have included this picture of my prototype racking. Of course, it is only one section and there will be many more pieces like this. I am looking to build a section that holds 9 horizontally mounted 250W panels. There would be a minimum of 12 concrete weights. Only 2 are shown. 4 ballast weights across and 3 deep supporting an array of 3 panels wide by 3 deep.

The wood 2X3 represents the short side of one of the 77" X 39" panels. Adjacent panels would share clamps in the horizontally run Unistrut

I am planning on using micro-inverters for my electrical connection.

Greg

Sounds like you're doing this yourself ?

If so, and none of my business but, I'd respectfully suggest you stop now.

Starters:

Will the roof take the loads ?

Wind is always a consideration. A lot or a little. As are seismic considerations.

What happens to a ballasted system on a slope or horizontal surface in a seismic event ?

Solar electric panels are not meant as insulation. Poor idea for a lot of reasons.

Any thoughts as to building permits/plan check/design review ?

Lots more.

[gmcmurry]

I am working on a ballasted racking idea for my flat roof at 34 degrees in Southern California. It seems I have the perfect location for many many panels. My house gets really warm, as it is pounded by the sun. When this project is completed, I will even appreciate the extra insulation I will get by having a major portion of my roof double insulated by a layer of solar panels.

My current design will use a Unistrut frame mounted on concrete ballasts. Wind is not a problem in my area.

My question is (I am sure this is the first of many) if I am mounting my panels in "landscape" mode, is there any reason I cannot clamp them to my horizontally run Unistrut on the ends? This would be two conventional clamps on the short ends. My panels will be about 6' 5" X 3' 3". I would have the clamps about 28" apart on the 3' 3" (39") side.

Almost every illustration I have seen, shows panels attached on the long side when in "landscape" position.

I need most of my power in the Summer, I am thinking of 15 degree tilt, direct facing South and rows 24 inches apart.

I would appreciate any comment.

140611 Racking Prototype 02_s.jpg

I have included this picture of my prototype racking. Of course, it is only one section and there will be many more pieces like this. I am looking to build a section that holds 9 horizontally mounted 250W panels. There would be a minimum of 12 concrete weights. Only 2 are shown. 4 ballast weights across and 3 deep supporting an array of 3 panels wide by 3 deep.

The wood 2X3 represents the short side of one of the 77" X 39" panels. Adjacent panels would share clamps in the horizontally run Unistrut

I am planning on using micro-inverters for my electrical connection.

Greg

[bcroe]

Racking

Is this the correct place to discuss various racking ideas? Greg

Sure, it's all very expensive. Some of us have used aluminum angle, steel, treated wood,
stainless steel connectors, or a combination of them. Bruce Roe

[gmcmurry]

Is this the correct place to discuss various racking ideas?

Greg