Before you do that....!
I have 3 solar panels on the roof held down by Scotch VHB
double-sided tape (#4950). I was not at all comfortable with this scheme until I started looking into the specs of this stuff and have since become a believer. See the link above and you might be too.
BTW- This stuff is very difficult to find in anything less than a roll (occasionally on eBay), but when I just bought my 3rd panel from AM Solar, I had them roll off $10 worth just to have around. That's not their business, but they might do it again.