Why there’s a required gap separating wind turbines? Ayrshire, Scotland, 28 December 2023 during storm Gerrit a wind turbine lost its wings as result of overspeeding during strong wind. The debris was flying at hundreds of meters.
Last year there was a similar case in South Wales and it came out that wind turbine needs electricity to turn its wings into a neutral position. If power is cut off, the turbine is unable to go neutral and this may result in such overspeeding and ultimately breaking the wings by inertial force or, as it happened in South Wales, collapsing of the tower.
To be fair, it needs electricity but doesn't need grid power. (Though I'd still expect the whole setup to be backdriveable and actively held so that wind would turn it to neutral on power loss.)
@kravietz the article talks about per-blade power supplies, which I think eliminates the possibility that it's about head turning
Even if you can't turn the head, you can always turn each blade individually into the wind (though this might be out of the range of is normal motion).
@robryk
I suspect the definition of “neutral” depends on the wind direction. If you have wings turned at 0° against the land surface it will only apply to two wings at any given time, while the other two will be angled at 90°. These will start getting pushed when the wind bearing changes so you need to turn the whole head and I guess that requires much more power than turning wings 🤔