Oh, I that he meant the bottom.
I was thinking the bottom of the panel would Neva similar material I'm strength and durability to the top. There wouldn't be a need for transparency as well, so you'd have more options (and cheaper)
The surface below the panels wouldn't be exposed to the elements. It would also be exposed to less wear.
Obviously there can still be some tweaks and design changes, but it seems like this is very practical. It would be cool to saw some actual studies and data on the panels though. Stress testing and stuff like that