I seen these also I was surprised that they were selling. I guess if you label anything as "wind turbine blades" they will buy them. I have some plastic gutters laying around think i will cut them down and put them up on fleabay.
If a pvc blade hit someone in a storm would they suffer less?
I really doubt these are blades meant for a wind turbine. There doesn't seem to be any leading edge. They look like something that could work for a vertical rig, but are nothing I'd imagine would be successful on a horizontal rig.