Solar Panel Mounting

[WStayton]

  I've been looking at solar panel mounting racks and have come to a couple of conclusions:

1)  Solar "roof racks" are insanely expensive for what they are.

2)  Each different make and model seems to specify thier "own" mounting system for them.

  From the above, I have come up with a few questions:

1)  Can you build your own mounting racks and have something that is acceptable?

2)  How do you waterproof the points where the racks mount to the roof?  My experience with mounting anything on a roof is that it is almost impossible to make them not leak.

3) Is there anything magic about the cute little doodads that they sell you for a kings ransom, that hold the panel onto the rack?  Could I improvise something for a third of the cost and not jeopardize the installation?

  My roof is not steep enough to mount the racks to it level with the roof - for optimum performance in the winter, the upper end of a four foot panel will have to be a little more than six inches farther from the roof than the lower end . . .

  I was vaguely considering building a rack system out of angle iron (not aluminum as the commercial systems are) and box tubing, and just sort of making it up as I went along . . . I'm sure that approach will generate howls of protest, but what, specifically, is wrong with it, since it would be about 1/3 of the cost of commercial aluminum racks.

  Again, I am cheap but I don't want to do something that I will have to do over again in a year - that is false economy.

  Also, whatever I do, it is going to have to pass muster with NYSEG in order to be hooked to the network, so my "creativity" is limited by what they will approve . . . They apparantly have two solar "inspectors" in this part of the state - one of them will work with you, is pretty knowledgable and has been doing it for a while - the other one is a P#$$@K, and wants it exactly the way they taught him in school - last week!  <grin>

  Any hints or suggestions, other than get out your check book and prepare for the worst?

  Thanx for any input!

Regardz,

Wayne Stayton

[mike90045]

Ever see rust stains running down a roof or a wall?  Use aluminum, or galvi steel.

After each roof support is on, weatherproof it, and then put a vent pipe jack over it,  no leaks.

[LowGear]

Hi Wayne,

If you're cheapest person in the world I feel your pain.  Sometimes a guy just has to bite the bullet and do it right.

Here's what I bought.  The 3/8" units were around $7 I think.  I push bad things out of my head.  It's a gift.  The black ones were a buck cheaper but what the Hell!  When first class is only a buck more I'm going first class.

Yeah, you could get by using reclaimed pallets and long sheet rock screws but this should be a twenty year very little maintenance program.  Nice stuff costs more!  What Mike didn't mention is that rust is a contagious disease which will eventually seep into your mind and poison future projects.  (Pretty heavy; huh?)

Casey

[Tom Reed]

The cheapest system is the one used on our system. The S5 mounting blocks clamp to the standing seams on a metal roof and create no perforations of the roof surface. Even so they were about $7 ea for an aluminum block with a groove milled in it, 2 stainless set screws and a mounting clip. Unfortunately the metal roof was $38k.

[WStayton]

mike90045:

   Actually, I was thinking to use galvanized painted with Rust-Oleum (sp?) or something similar, but was/am worried about the cut edges of the feet (remember I have to have the upper set 6" higher then tha lower set).  If I rustoleum the crap out of the cut edges of the feet, is that enough?  Of course, I'm sure that they will need annual touch ups if I do go this way.

  My roof is steel, but it is the kind that has a stiffening rib of about 1/2" every foot or so.  I was thinking to mount to a truss that came where the isn't a rib - Should each "foot"  have a rubber "gasket" under it?  I was thinking to make the legs out of 1.5: square tubing and weld a 2" x 5" piece of plate (1/8"?) on the bottom and top of each leg and then secure the legs to the roof with two lag bolts (each with a rubber washer and a steel washer) and secure a 2" x 4" to the top "foot" the same way to mount the panels to.  If I use treated 2" x 4"'s, in two layers, so I don't have a joint in both layers in the same place, mounted to the top of the "legs", and paint them once a year when I am touching up the feet, will they last long enough to be effective?  And, if I build the legs this way I assume that I would have to put the "vent pipe jack" over the leg before I weld it up, no?

  I could have my brother heli-arc them up out of aluminum if that is required, but that's kind of a court of last resort!  My personal heli-arcing is in the "not so good" category and I don't have the equipment to heli-arc.


LowGear:

  Whats a  "3/8" unit" that is/were "around $7"  Is this some sort of foot like I just reinvented above?  <grin>

  When I looked at commercially available "legs", as described above, they were $20 to $25 each in aluminum - since I need about 36 of them, for three "courses" of solar panels (total of 24 panels. . . 3 X 8 with 6 "legs" under each end of each course) it was what seemed like a pretty big number for what seemed to me to be a pretty small pile of aluminum.  Say $900 with shipping - that's why I started looking around!

  Like I said, I am cheap, but I try not to be foolish - pallets fall in the foolish category, at least for  me!! <smile>


Tom:

  I HAVE a metal roof, but I don't think that the seams stand up high enough to clamp anything onto!  Also, did you clamp both ends directly to the roof, because that wouldn't work for me, since I have to raise the toip end up for best winter performance.


On a last note:  Has anybody read/used/possessed the book "Photovoltaics: Design and Installation Manual"?  I was about to order it but thought that I should run it by the herein experts to see what they though of it before I spent my $35.00.  <grin>

  Is it worth the money and/or is there some other/additional book/manual I should buy to hold my hand?


  Thanx for the input guys - its all appreciated and a solar dummy like me needs all the help he can get!  <smile?

Regardz,

Wayne Stayton

[LowGear]

Hi Wayne,

Whats a  "3/8" unit" that is/were "around $7"  Is this some sort of foot like I just reinvented above?  <grin>

My entire 15 panel array sets on an aluminum uni-rack looking rail which sets atop an aluminum 2" Angle rail which is secured to the roof via 3/8 inch stainless lag screws/bolts.  The little red booties that cover the caulk that actually weatherizes the tin roof are what are about $7.  So just the lag and the bootie is about $15.  Lets see, 5 angle aluminum rails with 5 lags sounds like 15 ^ 2 or $225 in securing hardware alone.

As my mother-in-law tried to teach me - "Its only money  ."

Casey

[deeiche]

rm /

[LowGear]

The green stuff?

The extra expensive simulated patina on the roof that you can't see on a 4/12 pitch or under solar panels?

The Macadamia trees? Deciduous trees often get whacked here in Hawaii.

The garden hose for washing the aluminum drill castings off the roof?

Casey

[deeiche]

rm /

[WStayton]

About the green in the backgroud of LowGear's pix:

  Are you guys sure that isn't money waving around in the background???

  Sorry, LowGear, but I just couldn't keep myself from typing it!!! <grin>

Regardz,

Wayne Stayton

[WStayton]

LowGear:

  If you're still talking to me after the last post . . . <smile>

  I THINK that I need a "rail" under the lower and the upper end of each of three courses of solar panels, so six rails total.

  With eight panels each "course" of the array, the width of just the solar panels will be something like 25'ish feet . . . allow a couple of inches between each panel and the one beside it so there is room for a hold-down fastener and you have something like 27.5 feet.  I figured on six "legs" under each of these rails, so they will be something like 5.5 feet apart - is this enough, or do I need more?

  This isn't hurricane country but we do get some pretty good winds with the lake effect off of Lake Ontario and Lake Erie - though we are far enough inland to miss the worst of it . . . we got something approaching 50" of snow last year, while Syracuse, which is in the middle of the worst of the "snow-belt" got something over 160 inches!!!  I'm NOT moving to Syracuse any time soon!  <grin>  Sooo, I would classify us as moderately windy, FWIW.

   With the fact that they need to set at an angle to the roof to get optimum performance in the winter, they will be something like 2" to 3" from the roof on the lower end and 8" to 9" from the roof on the upper end - making them ideal to "catch" any wind from the north - fortunately, our worst winds seem to come from the west, upon a frontal passage.

  Will twelve "legs" under each course of eight panels insure that I won't have to pick them up out of the neighbors field?

Comments appreciated!

Thanx,

Wayne Stayton

[LowGear]

Please Wayne,

He who lives by the sarcastic pen should receive as he has given.

That green is nothing.  Here are a couple of photos of the money ditch out to The Menehune Lab (MEL).  We needed a ditch to get the money flowing out there.  By the second day my cheeks flinched every time that hammer went off.

As you can see by the last photo I do know the position for solar projects.

Just between two of the cheaper people on the planet it was fun to say "Screw-It!" and do things the right way.  Hell, I even got a permit.

Casey

[LowGear]

Hi Wayne,

I'd really check with the panel manufactures before I worried about 8 inches of rise.  I know you get some fantastic sun in that solar panel loving cold weather but 8 inches doesn't sound like much of an advantage to me.  At the same time one of the theoretical weaknesses of my design is that there isn't enough clearance for good air flow or cooling underneath the panels.

One thing I don't like about my array is that the center panels are out of reach once installed without a boat load of work.

The clips I used shared panels except on the end so mine have about one inch between panels. 

I think it's time for you to go down to your supplier and make friends.  The electrical contractor that I paid a $1000 to run the permit through (it's Hawaii bra) gave me Carte blanche so to speak on his account at the local supplier.  I saved $1500 on the panels not to forget the racking and the little red sacred boots.

Casey

[Carlb]

We have a total of 21kw installed on our property.  We did the installations in three phases 7, 3 and 11kw. With each install we had to apply for a permit.  The construction inspector wanted to see all of the info for the mounting system including the rated wind loading numbers for the racking system.  If you plan on designing your own mounting system be sure that it is acceptable to the building/construction inspector before you begin your install.

Carl

[LowGear]

Amen Carl.

Currently racking is in LaLa land here but No "certified" plan = no permit!

Casey