Friend had a small windmill with 6 foot blades and one of those broke off and stuck into the ground quite deep 100 yards away.
High winds and the brakes or whatever keeps them from too many RPM did not work.
This was in his yard on 80 acres not a month after the entire system was put together and the people would not stand behind it.
Every time he turned it on to make home electricity it ended up making his electric bill higher.
He had battery packs to store energy also.
Prague Ok.
He thinks the electric company was penalizing him for using it as it was hooked to the grid.
The electric company charges you retail price, but only pays you wholesale for any electricity you put back into the grid.
I looked into this quite a bit when we had the 228 acre farm. Most days you could barely set down an empty 5 gallon bucket there without chasin' it. :/