Wind power

[Segilla]

The traditonal windmill has a 'paddle' behind the blades which ensures that the mill always faces into the wind.

Presumably modern electricity generating wind turbines change direction - but how?

[xud]

I suppose the head of the wind turbine can be swivelled in such a manner to suit the local weather forcasts to maximise output. This will be done remotely as they are un-manned as far as I know.
Interestingly, I was told many years ago that wind generators take more energy to manufacture than what they pruduce in their lifetime. Surely, this can't be true?

[Hippy]

Modern wind turbines (the tall spindly white things on hillsides) move around to face the wind by a clever contraption called a servo. A detector picks up the stress on the blades and converts this to an electrical current fed to a motor to twist the head. Also, the blades can be "feathered" to take advantage of the wind or to idle or stop rotation in high wind thus avoiding damage to the workings.

[baileys]

was waiting for that answer Hippy, knew there was more to it lol

[chainfire]

I've got two turbines near me, and both have a small weather vain (spelling) on the top. I'm not sure, but I think that is connected to the turbine, and makes the head face the wind.

[BillyBB]

The energy and CO2 produced to manufacture and install a modern wind turbine means that they are not massively 'greener' than fossil fuel. There is much debate about this though.