BajaNomad - Need suggestions of materials for framework for solar panels

In Cabo, or anywhere hurricane prone, if you have a lot of $$ invested in panels, purchase commercial mounts rated for strong winds. Don't risk loosing your panels by making your own mount that will most likely fail in a hurricane.

Thank you for your unnecessary vote of confidence of my abilities. I'd rather not buy a commercially designed mounting system.

pacsur - 5-22-2016 at 05:47 AM

If your flat roof has parapet walls some homeowners will also install some type of flat hurricane protection over the panels using the walls as attachment points, sealing up the roof during hurricanes.
You can buy all the metal you need at Feyco in Los Cabos.
Start with the strongest anchoring system you can find, be sure to seal properly to stop new leaks, or have polyurethane spayed over roof after complete.
Overengineer everything if your not buying a tested mounting system for your panels.
The POR-15 is also great stuff.
Remember during a hurricane that the old saying about the weakest link really comes into play.
Buenos suerte...

Bob and Susan - 5-22-2016 at 06:11 AM

I just used treated 2x4's
I shot them with cement nails using a nail gun I borrowed...really secure
then tied the the 2x4's together with straps

then screwed the panels to the wood with angle metal

make sure you seal the roof really well BEFORE you mount the panels
or the nail holes WILL leak

if they lay flat no need for fancy mounts...but...my roof has a 2 foot "wind shield" around the entire thing

mine have been thru several hurricanes...they are still there
someday i'll probably have to replace the wood...not yet

BigWooo - 5-22-2016 at 06:24 AM

Thank you for your unnecessary vote of confidence of my abilities. I'd rather not buy a commercially designed mounting system.

Geez, sorry I ruffled your delicate feathers.

Bob and Susan - 5-22-2016 at 06:30 AM

hey bigwoo i'd take YOUR advice anytime...

mtgoat666 - 5-22-2016 at 06:37 AM

Thank you for your unnecessary vote of confidence of my abilities. I'd rather not buy a commercially designed mounting system.

Why not buy a designed mounting system? The industry is mature, the options are many; the mount systems are cheap, quick and easy. You want to build from scratch using tinker toys, you are a fool.
It's like saying "I want an LED light bulb for my bathroom, but I want to build it from scratch, where can I buy the components in Baja?"

Pescador - 5-22-2016 at 06:56 AM

A lot of people are going to Aluminum which will not corrode living on the ocean and they are strong.

durrelllrobert - 5-22-2016 at 08:46 AM

If you have enough space on your property why not ground mount the panels using readely available materials such as cement, concrete blocks and dimensional lumber or metal studs and save the worry of future roof leakage? Not related to that suggestion but here is a good read on solar systems, especially the wiring/ grounding of panels:

http://www.greentechmedia.com/articles/read/Eight-Ways-to-Make-Solar-Installations-Faster-Safer-and-Cheaper

imlost - 5-22-2016 at 08:57 AM

Quote: Originally posted by mtgoat666

Thank you for your unnecessary vote of confidence of my abilities. I'd rather not buy a commercially designed mounting system.

Apparently, some of you aren't familiar with Superstrut and Uni-strut in a solar application. These products are used extensively in the US in commercial solar projects. If you google "superstrut solar" you'll see countless examples of solar framework built with this, and I'm not just talking about small projects, but also large solar farms. It's arguably the most used material for commercial solar framework projects in the US. Saying that it's "tinker toys" and that I'm a fool for considering using these products is pretty extreme.

I'm not trying to pick a fight here. I'm simply asking what others have used. I don't want to spend big $ on a commercial mounting system. If you know of one that is affordable, then I'm interested in hearing about it. I have yet to find a commercial mounting system that is not priced way more than I want to spend. If you know of one - please bring it to the table.

imlost - 5-22-2016 at 09:03 AM

Are you going to ballast mount or penetrate the roof?

Great question. My roof is Tri-D construction, so I'm thinking it would be best to not make penetrations. If I did connect it directly, I'd question the ability of the Tri-D construction to hold down the panels in strong winds. For this reason, I'm leaning toward a ballast type mount - Either pre-made solid concrete blocks or hand-poured curbs.

My roof has parapet walls that are about 2' in height. They are also constructed of Tri-D.

imlost - 5-22-2016 at 09:06 AM

Quote: Originally posted by durrelllrobert

If you have enough space on your property why not ground mount the panels using readely available materials such as cement, concrete blocks and dimensional lumber or metal studs and save the worry of future roof leakage? Not related to that suggestion but here is a good read on solar systems, especially the wiring/ grounding of panels:

http://www.greentechmedia.com/articles/read/Eight-Ways-to-Make-Solar-Installations-Faster-Safer-and-Cheaper

Thanks for your suggestion. I have the room to mount these on the ground, but I'd rather have them on the roof, out of sight. I'm not planning to use the roof for living space.

imlost - 5-22-2016 at 09:09 AM

Quote: Originally posted by Pescador

A lot of people are going to Aluminum which will not corrode living on the ocean and they are strong.

I've read that corrosion can be a big concern, and so I haven't ruled out aluminum for this reason. I know that most good installations use rubber or plastic washers for assembly, just to prevent corrosion from dissimilar metals.

pacsur - 5-22-2016 at 09:17 AM

My first story is block construction, my second story and all the roofs are all tri-d panel, most likely unless you pre-planned to anchor to roof you probably won't have good base to anchor to.

imlost - 5-22-2016 at 09:20 AM

Quote: Originally posted by pacsur

If your flat roof has parapet walls some homeowners will also install some type of flat hurricane protection over the panels using the walls as attachment points, sealing up the roof during hurricanes.
You can buy all the metal you need at Feyco in Los Cabos.
Start with the strongest anchoring system you can find, be sure to seal properly to stop new leaks, or have polyurethane spayed over roof after complete.
Overengineer everything if your not buying a tested mounting system for your panels.
The POR-15 is also great stuff.
Remember during a hurricane that the old saying about the weakest link really comes into play.
Buenos suerte...

Great advice - Thanks. I'll check out Feyco, and POR-15.

I'm hesitant to make any penetrations in my existing roof, since it's not concrete. I'm leaning toward anchoring this in to concrete curbs or blocks that will just "sit" there. These could be sealed in position with the rest of the roof.

mtgoat666 - 5-22-2016 at 09:25 AM

You said you did not want a commercial system, then you said you are looking at uni strut's designed systems. You are making little sense. Isn't uni strut a commercial system?

There are several mfgs of solar rack systems. Just go buy the one recommended for your roof type. Call or email the mfg or distributor to ask which type is best for your particular roof.

Quote: Originally posted by mtgoat666

Thank you for your unnecessary vote of confidence of my abilities. I'd rather not buy a commercially designed mounting system.

imlost - 5-22-2016 at 09:33 AM

Are you going to ballast mount or penetrate the roof?

Guys on the mainland are going with those RV concrete mounting blocks... it's good concrete that won't degrade on you.

Hand pour would be easy, too.... you could make those bullet proof.

I am certain you have done roof load calcs.

You gonna set the array at latitude or when do you expect the need for most productivity?

Sorry, not impugning your knowledge, I am just curious!

Saludos,
Frank

Frank,
I haven't done calcs. I didn't build the house and the builder is not available for me to talk to, so I have to make some assumptions. I'm planning to spread the weight of the concrete around, so it's not in one place. I'm pretty confident the roof can handle the weight I'm planning to add. The roof was designed for the solar panels to be up there.

Regarding the angle of the panels - I'm not planning for the array to be adjustable. It was difficult for me to find a solar calculator that includes the BCS area, but we're at a similar latitude to Mazatlán, and the calculator suggested 67 degrees of angle (from vertical) for the summer months (which is when we'll have max usage). I'm curious to know what angle(s) other people have used for their systems.

Fernweh - 5-22-2016 at 09:43 AM

I built my own solar panel rack system, mounted to a flat roof with approx. 22" high parapet walls.
The roof structure, 12" metal joist, 3/4" plywood, torched on hd roofing.
I had bolted two rows of Uni-struts, for each solar array, through the roof structure, sealed the penetrations with a good polyurethane sealer.

Built the welded support structures from 1-1/2" x 1-1/2" x 1/8" angle, not higher than the parapet walls (almost perfect solar angle for La Paz), and bolted them to the Uni-struts with 3/8" spring nut system.

Using Uni-struts again, but this time welded to the support structure, layout to match the mounting holes in the solar panels. The Enphase inverter and cables are also mounted to these Uni-struts as well.

I then bolted the separate solar panels to the Uni-strut line, from underneath for theft protection (not that easy to do).

To increase the theft protection, I did install a steel 1" x 1" 1/8" angle over the edges of the solar panels, welded to the sub-structure.
Apparently that angle installation was to tight on one of the panels, it cracked the glass of it.......not so good, but is still working with 70% output.

Oh, by the way, Odile went over my place in 2014 - no damage to my homemade lousy structure

imlost - 5-22-2016 at 09:43 AM

Superstrut and Uni-strut are not proprietary hold-down systems for solar equipment. It's primarily used in commercial construction for hanging equipment from, such as electrical, HVAC, etc. My very first post in this thread identified this as my preferred mounting system. It's inexpensive and widely available in the US - I'm just not sure I can get it in BCS.

Quote: Originally posted by mtgoat666

You said you did not want a commercial system, then you said you are looking at uni strut's designed systems. You are making little sense. Isn't uni strut a commercial system?

There are several mfgs of solar rack systems. Just go buy the one recommended for your roof type. Call or email the mfg or distributor to ask which type is best for your particular roof.

imlost - 5-22-2016 at 10:01 AM

I built my own solar panel rack system, mounted to a flat roof with approx. 22" high parapet walls.
The roof structure, 12" metal joist, 3/4" plywood, torched on hd roofing.
I had bolted two rows of Uni-struts, for each solar array, through the roof structure, sealed the penetrations with a good polyurethane sealer.

Thanks for the pictures. That's a tight, professional looking install! It's giving me great ideas for how to assemble my framework.

imlost - 5-22-2016 at 10:40 AM

We're off-grid. Not sure if my generator will handle a wire feed welder, so I may not have a choice other than bolts.
I think it's rated at 7500w.

Fernweh - 5-22-2016 at 11:45 AM

We're off-grid. Not sure if my generator will handle a wire feed welder, so I may not have a choice other than bolts.
I think it's rated at 7500w.

Good tools make happy workers.....

Nice Miller Multimatic 200 (wire, stick and tic welder), 120 & 240V, works well with 3500W generator.

larryC - 5-22-2016 at 11:49 AM

7500 watt generator will handle a pretty big wire welder. I use a 175 amp mig welder and a 200 amp tig welder (one at a time) on my 6500 watt Kubota generator with no problems.

Fernweh - 5-22-2016 at 12:11 PM

67 from perpendicular sounds about right.

For year round production on a fixed array we use latitude (from flat so that would be 23 degrees)... the closer to the equator the less latitude (for lack of a better term) needs to be accurate.
Anything less than about 12 you don't get the benefit of rain cleaning them or just using a hose.

Soiling and heat kills production.

If you expect more demand during winter add 15 degrees to latitude and if summer time is your peak demand go down to about 12 degrees.

All about keeping that sun perpendicular to the array for as long as possible.

I love these discussions.

Probably not all that much weight, either... area of the modules divided by the weight of everything.... I am certain it is fine.

[Edited on 5-22-2016 by soulpatch]

Good points!

Another thoughts for grid-tied systems like mine:

When producing more power than you are using, you will feed into the CFE grid, and create KWh credits.
The different level CFE charging tiers, are have lower limits in the winter time, and it will cost more money to have a higher usage - so you want to produce the most solar energy during this period:
1.) to keep the CFE bill low
2.) to create more KWh credits, to use up in the summer time, when the AC's are running.
In the summer, the sun is almost directly overhead (La Paz), the day has more productive solar hrs, and this will compensate for any "summer misalignment", of your solar array.
Since the new digital meter has been installed, my CFE power usage is 2,300KWh, and I have send 4,500KWh back into the grid......
My solar array produced 17.52KWh on 5-21-2016. My bi-monthly CFE bill amounts to 46 Pesos.

durrelllrobert - 5-22-2016 at 03:15 PM

I then bolted the separate solar panels to the Uni-strut line, from underneath for theft protection (not that easy to do).

Very impresive and profesional. Since you hve plenty of kWh why not add a PVC pipe recirculating solar hot water heating system too?

Fernweh - 5-22-2016 at 06:06 PM

Thanks Bob,
for your kind words.

How about a solar only hot water heater? No LP gas connection, no electrical connection, but 50 Gal of hot water?

Two 96" x 48" hot water solar panels, copper interior with aluminum heat sinks, under tempered glass. 10W 12V solar panel for the tiny 12V re-circling pump at the water (heater) storage tank. Special bottom inlet/outlet fitting, with PEX pipe to and from the solar panel on the flat roof, next to the electrical solar array.

Water Works in my Bodega (no solar connection yet)

50 Gal LP Water heater, with solar panels connected - no Gas or Electrical

durrelllrobert - 5-23-2016 at 07:55 AM

Thanks Bob,
for your kind words.

How about a solar only hot water heater? No LP gas connection, no electrical connection, but 50 Gal of hot water?

Two 96" x 48" hot water solar panels, copper interior with aluminum heat sinks, under tempered glass. 10W 12V solar panel for the tiny 12V re-circling pump at the water (heater) storage tank. Special bottom inlet/outlet fitting, with PEX pipe to and from the solar panel on the flat roof, next to the electrical solar array.

Where do buy the PEX tubing and fittings?

Water Works in my Bodega (no solar connection yet)

50 Gal LP Water heater, with solar panels connected - no Gas or Electrical

imlost - 5-24-2016 at 08:13 AM

Fernweh,
That's very cool. Are the panels commercially made? Are they for heating pools? Did you import them, or are they available in Baja? Is this a gravity feed system to your casa? - I noticed your water heater is mounted up high on the wall.

monoloco - 5-24-2016 at 10:41 AM

Are you going to ballast mount or penetrate the roof?

I used 2" aluminum angle to make panel mounts, and attached them to the roof using stainless lag screws into lead anchors, and bedded them in with 3M 5200, my next door neighbor used a ballast mounting system produced specifically for solar panels. My panels made it through hurricane Odile and he lost 18 out of 20 panels. The problem wasn't with the ballasted system, it was all intact, what failed were the provided clips that attach the panels to the mounting system, the wind load on the panels straightened them out. If you bed the anchors for the mounts with 5200 or another type of polyurethane marine sealant you will have no problems with leakage.

[Edited on 5-24-2016 by monoloco]

Fernweh - 5-24-2016 at 11:35 AM

Fernweh,
That's very cool. Are the panels commercially made? Are they for heating pools? Did you import them, or are they available in Baja? Is this a gravity feed system to your casa? - I noticed your water heater is mounted up high on the wall.

Yes, those panel were commercial made, for hot water - not for pool use. I had them for a long time, maybe twenty years or so. They were used then already. I brought the to La Paz, gave my friend two, and kept the other two. Had them re-worked a bit, the copper interior still perfect.
The water heater is mounted high, to utilize the space underneath, and to reduce the head height for my little 12V Chinese made solar pump.
It is not a gravity fed system, everything is under pressure from a separate pump system, but I do have a separate 1100 L tank on the roof for emergencies......

monoloco - 5-24-2016 at 02:25 PM

Wow, those must have been crappy clips because, usually, you spec a ballasted mount for expected wind speeds.

I wonder if they low-balled it.

We are waiting word on a system we bid south of Sayulita that we are building for 200mph winds.
It is a ground mount but we will also build some walls around it to reduce lift.

Thank god for capable engineers!

The funny thing is that my neighbor's an electrical contractor from California, and the kind of guy that researches the hell out of things before hand, and he installed the mounts himself. It all looked bombproof but a bunch of 50 cent parts were it's downfall.

Cancamo - 5-25-2016 at 12:21 PM

Aluminum angle available at shop up on " Calle Hancha ", (the next big street west of "Alta Tension"), in Zacatal, ((easy to find). Buy in 5 meter pieces, cut to size, use small angle pieces for mounts. Use taquete inserts for mounts, seal accordingly. Easy to cut, drill, won't rust....bolt down flat in hurricane season, raise to the south in winter.
About three sixteenths of an inch thick.

Has endured hurricane Juan, Odile,....and other storms, mounted on flat roof with parapet sides.

Easy, and permanent.

imlost - 5-29-2016 at 12:12 PM

There's a construction supply place on Hwy 1 in Zacatal. I think it's called "Panel Rey". Is this the place you're talking about?

Another person who has a house in my area, sent me some pictures of the frame he built out of aluminum angle - It looks very similar to what you described. I like the idea of being able to raise & lower the frame, especially during hurricane season. I'm leaning toward this type of construction. It seems really simple and effective, and I like the idea that it would be aluminum (angle) against aluminum (panels).

Quote: Originally posted by Cancamo

Aluminum angle available at shop up on " Calle Hancha ", (the next big street west of "Alta Tension"), in Zacatal, ((easy to find). Buy in 5 meter pieces, cut to size, use small angle pieces for mounts. Use taquete inserts for mounts, seal accordingly. Easy to cut, drill, won't rust....bolt down flat in hurricane season, raise to the south in winter.
About three sixteenths of an inch thick.

Has endured hurricane Juan, Odile,....and other storms, mounted on flat roof with parapet sides.

Easy, and permanent.

imlost - 5-29-2016 at 12:21 PM

I like the idea of concrete anchors, but with Tri-D construction, I'm concerned that there may not be enough bite in the concrete to make it work. maybe stainless steel Toggelers would be the better way to go. Thay way, I could penetrate through the concrete layer and have the hold-down on the styrofoam-side of the wire mesh. Alternately, I can use concrete blocks or poured concrete curbs for ballast with typical concrete anchors.

I agree - Polyurethane sealants are pretty bomber.

Quote: Originally posted by monoloco

Are you going to ballast mount or penetrate the roof?

surfhat - 5-29-2016 at 12:59 PM

I built a tri-d panel structure twenty five years ago on the east cape and had my PV panels mounted in a tracker frame that gives the most efficient energy absorption and allows plenty of air space for the panels to work at their highest efficiency. They have survived several hurricanes and the thought of mounting them on the roof never entered the equation. Tracking that sun throughout day is key. The hydraulic oil in the tracking frame automatically follows the suns angle so there is no energy loss whatsoever. Penetrating a sealed roof for whatever reason should be avoided. I hauled the tracker frame on the top of a small suv and at 5am crushed right on through. Things may have changed since then but the efficiency of the tracker remains. Thanks to all here.

surfhat - 5-29-2016 at 01:10 PM

I meant to say that the border crossing at that early hour of 'cruising through' was a breeze back then. My vehicle was stuffed inside and up on the roof rack with the tracker frame, gel cell batteries inside, a trace inverter, and a whole host of other items that made it down there easily through the border crossing.

The value of an automatic tracker cannot be disputed. There is no need to put any holes in your roof when such a better option is available.

imlost - 5-29-2016 at 01:58 PM

The tracking mount sounds interesting, but I haven't found any of this type of system that is cost effective. Yes, you can get about 25% or more efficiency out of your panels with tracking, but panels are relatively inexpensive now, so believe the loss of efficiency is made up for by increasing the quantity and/or output of panels - which is considerably less expensive.

Mounting the panels anywhere else but the roof is not an option for my circumstance.

Importing this system in to Mexico was fairly painful. including freight and duty it added more than a third to the original cost of of the system (than the purchase price in the US).

imlost - 5-29-2016 at 07:13 PM

Oh. I'm all about low complexity. I'm like a completely different person in Baja. It's more about less.

willardguy - 5-29-2016 at 07:34 PM