Can 12 solar panels be roof mounted at 45-50 degrees on a roof with 1/4 or 1/5 pitch?

[Silver_Is_Money]

Would a typical residential homes truss roof be able to sustain 12 solar panels (~65" x ~39.5", and weighing ~43 lbs each) mounted at a pitch angle of 45 to 50 degrees if the roof itself has roughly a 1/4 or 1/5 pitch (roughly 18.5 or 22.5 degrees)? Or would this cause wind related lift that may structurally damage the roof? In practice is this sort of panel mounting actually done, or is it even possible? I would rather have the panels mounted at 45 to 50 degrees than at roughly 20 degrees, in order to slightly favor winter sun over summer sun (even though there will be a noticeable overall reduction in annual KWH) . The application will be off-grid.

[J.P.M.]

Would a typical residential homes truss roof be able to sustain 12 solar panels (~65" x ~39.5", and weighing ~43 lbs each) mounted at a pitch angle of 45 to 50 degrees if the roof itself has roughly a 1/4 or 1/5 pitch (roughly 18.5 or 22.5 degrees)? Or would this cause wind related lift that may structurally damage the roof? In practice is this sort of panel mounting actually done, or is it even possible? I would rather have the panels mounted at 45 to 50 degrees than at roughly 20 degrees, in order to slightly favor winter sun over summer sun (even though there will be a noticeable overall reduction in annual KWH) . The application will be off-grid.

Good question. Good answers can come from an analysis done by someone knowledgeable in structural analysis and external loadings. Such folks are usually P.E's trained and experienced in such things. Each situation is different and perhaps unique. In practice, configurations of the type you mention occur all the time, and one of many reasons why there are engineers.

[VTSE]

Would a typical residential homes truss roof be able to sustain 12 solar panels (~65" x ~39.5", and weighing ~43 lbs each) mounted at a pitch angle of 45 to 50 degrees if the roof itself has roughly a 1/4 or 1/5 pitch (roughly 18.5 or 22.5 degrees)? Or would this cause wind related lift that may structurally damage the roof? In practice is this sort of panel mounting actually done, or is it even possible? I would rather have the panels mounted at 45 to 50 degrees than at roughly 20 degrees, in order to slightly favor winter sun over summer sun (even though there will be a noticeable overall reduction in annual KWH) . The application will be off-grid.

this formula should help you all year round at the position to know if you get maximum yeild

90 degree- your latitude= optimum fixed year round setting.

[foo1bar]

Would a typical residential homes truss roof be able to sustain 12 solar panels (~65" x ~39.5", and weighing ~43 lbs each) mounted at a pitch angle of 45 to 50 degrees if the roof itself has roughly a 1/4 or 1/5 pitch (roughly 18.5 or 22.5 degrees)? Or would this cause wind related lift that may structurally damage the roof? In practice is this sort of panel mounting actually done, or is it even possible?

Possible? Maybe.

But that's going to be a significant tilt - it'll catch a lot of wind. Going from a 4/12 pitch (18.5 degree) to a 45 degree pitch (12/12) means that you will have the top edge ~36" higher than the roof. (with just 1 portrait row) That's a big amount of surface area for the wind to push on. I would believe there would be a lot of lifting force being exerted even with fairly small winds.

And with lots of lifting force you need a good strong tie to the structure and down to the ground.
I think it is possible to have trusses that would handle the weight and wind load.
BUT most likely if they're trusses they were analyzed and designed to be as cheap as possible while still handling the "normal" load of roofing material. And because they were designed to be cheap they won't have oversized framing members that could support significantly more load.like you want to do.

What if you just increase the number of panels and mount them parallel to the roof?
Might be cheaper than getting a civil engineer to analyze your roof and paying to reinforce the roof and paying for custom racking.

Or go with ground mount system. (ground mount will be easier to clean off the snow in winter if that's a concern for you)