Thanks in advance for your input.

We are about to build a workshop (20x30...nothing major) on our property in south Louisiana, and I was thinking of eventually installing solar panels on it to supplement our power use and potentially provide enough power to run some basics after major storm outages.

The solar panels are years away, but the workshop is going up this winter. But I have some questions about future proofing this workshop and making it compatible with our needs years from now. And I have zero interest in solar arrays mounted in the yard - I only want roof mounted options.

Questions:

Do panels have to be aimed south?

If the gable ends are facing north and south, will panels on the east and west facing parts of the roof not be feasible from a power generation perspective?

How hurricane-resistant or hail resistant are roof mounted solar panels traditionally?

The workshop will have a 130 mph rated metal roof, so hopefully won't need frequent post-storm repairs - but I'm not sure how the roof perforations would work for the mounting hardware. Anything I should try to bake into the design of my workshop?

If you have solar panels, do you have any recommendations for me to help make this process smoother?

Any reputable installers in south Louisiana that are not complete frauds?

This post was edited on 8/14/24 at 9:49 am

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Posted by notsince98

KC, MO

Member since Oct 2012

20116 posts

Posted on 8/14/24 at 10:16 am to frequent flyer

panels dont have to be aimed in any particular direction but their output and efficiency capabilities will change based on direction.

If you have two different "sets" of panels facing different directions, the different sets will each have to have their own inverter or you'll need a more sophisticated inverter with multiple MPPTs. You'll need one MPPT for each "set".

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Posted by mdomingue

Lafayette, LA

Member since Nov 2010

38336 posts

Posted on 8/14/24 at 3:29 pm to frequent flyer

quote:
Do panels have to be aimed south?

South is ideal because of the transit of the sun in the northern hemisphere.

quote:
If the gable ends are facing north and south, will panels on the east and west facing parts of the roof not be feasible from a power generation perspective?

Not Ideal, you would be much better off facing them south if it is feasible. Having panels facing east and west will mean that half your panels will be putting out max while the other half will be much lower or even zero. Facing them south gets you maximum output on all of them most of the day.

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Posted by notsince98

KC, MO

Member since Oct 2012

20116 posts

Posted on 8/14/24 at 3:33 pm to mdomingue

quote:
Facing them south gets you maximum output on all of them most of the day.

But you can only install 1/2 the amount.

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Posted by mdomingue

Lafayette, LA

Member since Nov 2010

38336 posts

Posted on 8/14/24 at 3:51 pm to notsince98

quote:
Facing them south gets you maximum output on all of them most of the day.

But you can only install 1/2 the amount.

Right for the same output, maybe better with half the panels, no need for any consideration of additional equipment for using the panels from both sides of the roof (though I do not know that you would really need much more than the appropriately sized power diodes). The overall cost of installation would be substantially less, I would think.

Here is a pretty good representation of what the solar transit looks like in South Louisiana

Perhaps a possibility for the op is to put them on the east and west slopes but tilted toward the south with some separation so as not to cause the forward array to CST a shadow on the arrays further back?

I think talking with a professional installer would probably get him some ideas about how to address his issue.

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Posted by billjamin

Houston

Member since Jun 2019

15101 posts

Posted on 8/14/24 at 7:15 pm to frequent flyer

quote:
Do panels have to be aimed south?

As previously noted it’s ideal but not necessary. Roof pitch will have a large impact on how well east/west facing modules will produce. You can use PVWatts to see production impact at various tilts and azimuths.

quote:
If the gable ends are facing north and south, will panels on the east and west facing parts of the roof not be feasible from a power generation perspective?

It’ll just impact your yield (kWh/kWp). Basically you’ll just pay more.

quote:
How hurricane-resistant or hail resistant are roof mounted solar panels traditionally?

Pretty good just go with a good tier 1 module and you’ll be fine unless you get a really bad hail storm. I think most are rated to 1” @ 50mph. Look for a UL61730 rating.
There’s racking out there that can go 180+mph. Most is 150. There are also high load modules that are 5400Pa load rated. I only see those used in Miami though.

quote:
The workshop will have a 130 mph rated metal roof, so hopefully won't need frequent post-storm repairs - but I'm not sure how the roof perforations would work for the mounting hardware. Anything I should try to bake into the design of my workshop?

Run the wiring and have your roofer install the Jboxes to make sure they’re sealed up good. Also run wire pulls in insulated walls.

quote:
If you have solar panels, do you have any recommendations for me to help make this process smoother?

Get a good irradiance analysis with a tool like Aurora if you have any shade from trees or obstructions. Decide if you need a module level system or string level will suffice and pick where you’ll want the inverter and preferably but the panel close to that. Most systems are not easy to expand and require repermits and interconnection authorization so do it once and do it right.

This post was edited on 8/14/24 at 7:20 pm

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