I think it's awesome they will get re-used.
Me too.
I saw some large lots of panels that had defects, such as snail trails and cracking vinyl back sheet. Supposedly they were still working so I don't know if they were replaced preemptively or under warranty or what. And then there are the ones I got, where the building was being demolished. I have heard of some large ground Mount sites getting dismantled, but I don't know what the backstory is with those.
Well, that must be an interesting story. Off hand, I can't see why anyone would do that. It's got to be like 99% or better of the cost of ownership is sunk costs in panels and infrastructure. I don't know what the maintenance costs per kW-hr might be, but even with a rate structure change, any money you get is good money. Taking the panels down doesn't change whatever your financing costs are; the bank still wants their money.
Will you be installing a rail system like Iron Ridge or can you fabricate your own underside of rafter strapping system?
I'll just lay them directly on the rafters and probably attach them with this or something similar. That is what I did on the other part of the building
Around here, unheated Buildings that have trusses and metal roofing ("pole barns") almost never have sheathing on them. Per the engineer at the trust company, they need 2x4 purlins every 2 ft but he said they could be on the underside of the top member.
Understood. But (again) Structural Engineers I work with tell me that the metal panels that you and I are thinking about skipping (because I have pondered your path, as well), once it is screwed down . . . is an important part of what I think they call "shear strength." Maybe think how a sheet of plywood keeps a Rectangle Shape -- rather than turning into a parallelogram? It works like for the whole building during Wind Loads. Maybe ask them about that? I am just thinking we may need to add some form of diagonal bracing.
I dont believe so. The engineer at the truss company said I just need purlins every two feet, either top or bottom of the top truss member. I told him I was using solar panels AS the roof.
The purlins electrofelon is talking about perform the anti-racking function usually handled by the roof deck. Although, at every 2 feet, that's a lot of board feet of lumber.
We can usually get amish rough cut for pirlings a lot cheaper than full decking or even #2s at lumber yard.The purlins electrofelon is talking about perform the anti-racking function usually handled by the roof deck. Although, at every 2 feet, that's a lot of board feet of lumber.
Purlin - Wikipedia
en.wikipedia.org
Understood. We have also used (big happy breath) Unistrut (choirs of angels sing) for this type stuff. Creates hard mount point(s) as part of the structure.The purlins electrofelon is talking about perform the anti-racking function usually handled by the roof deck. Although, at every 2 feet, that's a lot of board feet of lumber.
Purlin - Wikipedia
I don't know if they are still available, but you used to could get mid clamps as long (or as wide, depending on how you look at it) as the long dimension of your modules so that you didn't have that gap between modules that lets the water though the array.
Yeah, I think getting it water-tight -- or at least rain-tight should be a do-able thing. Probably some minimum slope design would be good - like maybe a minimum of 15 degrees -- but for optimal Solar in the US more likely 30 degrees or more. For Texas (my base) Snow build-up and leaking is not so much a consideration, but maybe should consider that for further North.
Without any diagonal members, I do not see how the purlins add any signiificant anti-racking element other than the torque resitance provided by a multiple nailing pattern at each crossing.The purlins electrofelon is talking about perform the anti-racking function usually handled by the roof deck. Although, at every 2 feet, that's a lot of board feet of lumber.
Purlin - Wikipedia
Yeah, I figure folks here are more about the Electrical and the re-use, etc. This is why we keep friendly relations with the Structural and Civil folks.
The extremes are simple - RSD is required for PV on buildings and not for ground mounted PV - but the dividing line between where it is and is not required is not that clear to me.
