Andy wrote:
I would be much more worried about structural integrity of one's
roof. Also, as you pointed out, a conversation with the insurance
company seems an important step for me, too.

***** While the panels do add some weight, it would be distributed
over
a wide area, and I doubt it would bother the structure , especially if
there
were only one layer of shingles. Personally, I'd be more worried
about
how the panels are attached to the roof, since it would certainly
involve
drilling some holes.... a LOT of holes..... which, over time, might
cause
a problem..... If it did, it would probably be a bear to try to fix
and patch...

i have a flat foam roof, but panels are installed on stanchions and not
directly attached to the roof structure on both flat and non-flat roofs. the
stanchions are tied through the roof into the rafters, and then the roof
penetrations are resealed.

there's less weight considerations for the modules than there are just
walking around on the roof. you do have wind loading to worry about, and of
course, hail. you also have to worry about shading from any means, like
chimneys, antennas, trees, etc. ideally it should face south, and you should
be able to see the horizon both to the east and west.