Maybe I'm just being pessimistic, but the failure mechanism is the erosion of the underlying denuded ground in a large storm to the point that the underlying structure moves.
I don’t think that’s being too pessimistic. I didn’t think about that. The solution would be some sort of concrete footing or something—but I’m sure that is more expensive than just mounting these panels in the air.
It looks like they're probably targeting places where huge rain isn't an issue and it looks like they do some site work to raise it up a bit? Theres another photo here :
