I have a fiberglass and textured roof and took a chance on VHB.
I'm not ready to drill holes in the roof just yet.
Two 3'
aluminum angle irons flank the one 100 watt panel.
The angle iron is bolted to the panel sides.
Roof and aluminum carefully cleaned with denatured alcohol.
Applied 6' of wide VHB tape (3' on each side).
Pressed down, then pressure applied with J Roller.
As insurance, I've attached nylon safety straps to the panel and the ladder.
If the panel lets go, it'll make a helluva racket but shouldn't fly off and whack the person behind me.
It's only been a few months but they're rock solid on there.
I may apply Eternabond tape over the angle iron for extra stick.