Panels as Sheathing?

[Ampster]

I'd have to wonder if PV panels might add similar strength to the building as a tin roof.

The structural integrity discussed earlier can come from nailing plywood with a specific nailing pattern. In that use it is often called sheer panel not sheating. I doubt there is much sheer strength from solar panels based on four Fasteners per panel, two of which are often share with the next panel. Then then any strength is spread out over less Fasteners to hold the racking to the rafters under the roof. That engineering is for uplift only and does not factor sheer strength.

 

[Kornbread]

Other ways of mounting such as directly attaching the bottom of the aluminum frames with lag bolts/screws to the roof trusses. Such as in SignatureSolar's projects https://shop.signaturesolar.us/blogs/news/diy-solar-panel-ground-mounting I would consider these examples very close to what we commonly call a pole barn. Of course, we called them pole barns because they were generally constructed with old discarded utility poles set deep in the ground, which provided the majority of structural integrity. They were simple structures to keep the farm equipment dry or provide shelter for the animals.

Besides ... have you seen the quality of some of the prefab sheds today?