Problem installing Solar Panels

I got the panels mounted. I used #12 1" screws. The plywood underneath isn't very strong for drilling screws in. I had to drill slowly until the screw bit, then hand tightened a 1/2 turn. It felt pretty solid when I dry tested it. Once it tightened, even the smallest turn at slow speed stripped in. I would have been happier to screw in tight without babying it, but between those screws and a bunch of dicor, hopefully it will hold.

Thank you for some good alternative suggestions. As for the people who state the obvious trying to mock; that doesn't help.