Originally Posted by Sagecoachdriver
WolfWhistle-Very nice and clean install! Thanks for the photos.
A few of us have started our installs of wiring, controller and cut-offs. Still in the planning stage of panels and mounts. With our Pebbled roof (dimpled) and the thinness of the fiberglass and plywood it was suggested that hollow wall expanding anchors be used. I may use that with a layer of 3M 5200 under the mount and a large dose of Dicor to top it off.
Not sure the tilting mounts will work with larger panels with only the mounts on 2 ends instead of all four. The advantage of the smaller panels is if one gets shaded, the others will still generate power.
S, I've seen an installation of panels on a fiberglass roof using the Well Nuts 05CD spoke of. They look like a very nice way to fasten, when you can't get to the back side.... nice that they can be removed.
There is a company that sells the tiltable mounts and they (well nuts) come with them, but I could't find it... on youtube. I've also see the 3M double sided tape (is that the 5200?)used on aluminum or fiberglass without fasteners of any king that is supposed to be rated for more wind speed that you would ever put it through. I am not sure I like the idea of tape ONLY, but I like 1/2" grade 8 bolts where a zip tie would work.
As far as shade. As you have probably seen, if you were to hold a hand directly in front of only one of the 36 PV sections on a panel, that panel output drops to nil; much like an open in a circuit, but if placed in a low light or even shade the output down a bunch but not completely out.
As I understand it, panels wired in parallel allow each to "stands" on it own, causing you to lose that panel, but if you were to put them in series, such as some of the high voltage setups, one panel shaded effectively kills the whole string. That is a good reason in my book, to go with 36 cell panels in parallel.
There seems to be an advantage of having more smaller panels verses fewer larger panels, but this is also driven by the amount of solar panel friendly space on your roof. Shade from ACs, vents, antennas have to be avoided like the plague.