Panel Racking

[HX_Guy]

No, I don't have them but will be using them in my future intall.

Look at Renvu.com, they have the 305W panels for a good price and ship out of California I believe so shipping won't be terrible.

[gmcmurry]

Great brochure with lots of great information. THANKS!

Are you an owner of Canadian Solar panels? If so, do you believe they make a good panel for a DIY project?

I have just started looking around for panels. There are so many different manufacturers.

Since they are kind of heavy, I guess I should try to find a local distributor to avoid expensive shipping.

Greg

[HX_Guy]

Yes, it's from the Canadian Solar Module Installation Manual, see here: http://www.civicsolar.com/sites/defa...-ul-154727.pdf

[gmcmurry]

HX_Guy,

Thanks -- This is exactly the type information I was looking for.

I have been looking at Canadian Solar so I will pursue this further and make sure the panels I get meet that requirement.

For both looks and strength, I am trying to keep my panels as low to my roof as possible. This will help in my planning.

Just yesterday I got a flyer with this picture...

BlueSky Energy Solar 01.jpg

This is the first I have seen of side mounting and now getting your information, I have good info to work with.

Is your drawing from Canadian Solar?

Greg

[HX_Guy]

It really depends on the panel and how it's designed and built. Some panels specify that you can only clamp on the long side while others say you can clamp on either the short or long side, such as Canadian Solar panels.

[gmcmurry]

Thanks for your considered reply.

As I mentioned, I am only in the planning stages.

My roof is extremely strong. It is made of 6 X 12 solid wood beams. I work with structural engineers regularly in my work so I don't have much concern for the actual strength of my roof. I have discussed my with some of them and will continue to do so.

You are right about the system moving around if there is an earthquake. I have lived in this part of the country for over 60 years... I know what goes on. There is a level of protection that is necessary but beyond that, the entire building would fall down and then, who cares. Lateral movement during seismic activity is indeed a problem. I was planning on a stainless steel cable system to keep the system in place. Also, there will be rubber pads between the weights and the roofing material. These will minimize any sliding around during minor temblers.

Codes in this area allow for heavy air conditioners to be placed on rubber isolation pads on flat roofs. My plan is similar. However, codes are not my baseline. Many homes here fell down during past quakes that were homes "made to code".

As I do with my work, my system will be severely over engineered.

Where I live, one cannot get away with un-inspected home improvements. I have lived places where nobody cares what you do to your house, but this area is not that way.

I mentioned before that we have many flat roofs in my area. Most commercial installers lean towards ballasted installations in those cases.

I always like to point out that the term "flat roof" will mean different things to different people. We have roofs in this part of the country that are really flat. I mean zero pitch. Basically, if it rains, which it rarely does, the water just falls off wherever it can. That is the case with my roof. The roof is basically designed to "pond" with up to 1/2 inch of water and then it overflows. The final water evaporates. For this reason, I avoid any roof penetration whenever possible. This is why I am beginning with a plan where that will not penetrate my roof at all.

As for my Unistrut frame, my prototype section is only a beginning. I have designed many structures with Unistrut and it is extremely strong. My final frame will be even lower to the surface of the roof than shown. Bruce made a good observation and I responded gratefully.

My original question posted was about clamping solar panels from the "ends" rather than from the "sides". Most all the installations I have seen have used two clamps on each of the long sides. I was wondering if anyone had experience clamping with two clamps on each of the short ends when panels are in portrait mode.

Greg

[Shockah]

gmcmurry, this a FREE forum where PRICELESS advice has already been shared.
However, there is no satisfaction guarantee.

I actually enjoyed the first part of this DIY thread... as I am a DIY advocate.
That pesky word "insulation" had to come in the room and ruin things.
Basically, you are shielding your roof-top from the sun... but not insulating your structure from the heat.
I agree with you though, that the interior should be cooler just from the shielding.
I once shielded a concrete roof-top office with a layer of corrugated steel 12"' above.
The results were noticeable.

Two things caught my eye- Your ballasts look good,,, and your workshop floor clean.

However, if you "needed" the suggestion to gusset the corners, then you might want to humble down a bit and realize you may be a bit over your head on this project.

Check out this flat roof install where all it took was a gust of wind to tear the array into pieces. ... <<< and this was a professional install.

Also, I have to concur that concrete ballasts do move under the slightest seismics.
If you can't penetrate the roof for anchors, then at least mount tethers on opposite fascias to keep the ballasts from sliding off the roof.

Good luck with your project. Please post photos of your progress.

[J.P.M.]

And those who are quick to take offense will often do so even when none is offered.
'Nuff said?

Amen.

[inetdog]

Those that find the need to constantly remind everyone that they are speaking respectfully, never are.

And those who are quick to take offense will often do so even when none is offered.
'Nuff said?

[gmcmurry]

Those that find the need to constantly remind everyone that they are speaking respectfully, never are.

[J.P.M.]

This is a tough room...

I've always tried (with limited success) to remember to not take my self too seriously. However, I always took my engineering very seriously.

An uninformed, cavalier attitude about the things of which you write is, first of all, possibly unsafe. IMO, you're out of your league in the design dept.

For my part, I'll take your remark about a tough room as a positive one. For your part, I'd respectfully and sincerely suggest you take what you need and leave the rest as your needs dictate.

[gmcmurry]

To answer your question: Yes. Simply confirming before I continued. Where's the harm in that ?

Take my thoughts as your needs dictate. Scrap the rest.
As for the rest:

Ballasted systems have been around for a long time for many applications. I've even designed a few for some non solar applications back in the day.

From what you write, it seems we have different ideas of how the engineering design process works and what's considered safe, appropriate and fit for purpose.

For example, I'm not sure the design feature of no penetrations on a flat roof is "far safer" than not considering wind loadings which are always a design consideration requiring some analysis more than" Wind is not a problem in my area", or safer than the possibility of a collapse failure caused by failure to check all design loading conditions against roof strength, or array movement caused by wind, seismic or other external sources that would impact the design.

FWIW, my understanding is that shading an area is not quite the same as insulating an area. For starters, shading prevents energy from reaching a surface. Insulation usually slows the transfer of energy (in this case heat) through the roof/wall/structure. The two are not the same.

Contrary to what you may think or write, unless you put the panels directly on the roof surface you will definitely get no insulation benefit by installing solar panels. That you may think that is so does not increase my confidence in the rest of your design capabilities.

I wish you luck with your venture.

This is a tough room...

[J.P.M.]

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

To answer your question: Yes. Simply confirming before I continued. Where's the harm in that ?

Take my thoughts as your needs dictate. Scrap the rest.
As for the rest:

Ballasted systems have been around for a long time for many applications. I've even designed a few for some non solar applications back in the day.

From what you write, it seems we have different ideas of how the engineering design process works and what's considered safe, appropriate and fit for purpose.

For example, I'm not sure the design feature of no penetrations on a flat roof is "far safer" than not considering wind loadings which are always a design consideration requiring some analysis more than" Wind is not a problem in my area", or safer than the possibility of a collapse failure caused by failure to check all design loading conditions against roof strength, or array movement caused by wind, seismic or other external sources that would impact the design.

FWIW, my understanding is that shading an area is not quite the same as insulating an area. For starters, shading prevents energy from reaching a surface. Insulation usually slows the transfer of energy (in this case heat) through the roof/wall/structure. The two are not the same.

Contrary to what you may think or write, unless you put the panels directly on the roof surface you will definitely get no insulation benefit by installing solar panels. That you may think that is so does not increase my confidence in the rest of your design capabilities.

I wish you luck with your venture.

[gmcmurry]

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

Good point - a few carefully placed diagonals will be added to the structure. THANKS

[russ]

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. But is your roof designed for the load?

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 - There is a big difference between shading a roof and having insulation. It will help yes - actual insulation would help far more.

Comments in bold within the text.