Actually that is fairly common. Too much windspeed will damage windmills, so they have a build in "self-protect device" that changes the pitch on the blades so they can't spin, or even a brake so they don't destroy themselves by spinning too fast (and causing damage) in high winds.
I didn’t have an anemometer on me but my impression was that this was the “normal” onshore wind pattern in this area.
I’d guess about 20/25mph steady winds.
All the vegetation is leaned over to the leeward direction.
TRUE. Those THIN LONG BLADES cannot spin very fast.
Now, here is something that doesn't take up much space, doesn't matter which way the wind is blowing, can deal with shifting winds, doesn't matter how FAST the wind is blowing, DOESN'T MAKE A THUMPING SOUNDS, and is actually FUN to watch SPIN.