There's no structural reason why you couldn't build one in your garden. Would be a pretty lawn ornament (I like windmills), what would it be for ?
The usefulness of huge, industrial sized ones on top of hills in specially selected places is arguable.
Putting one in a garden is the stuff of the Good Life (am I showing my age here ?)
Unless you have a big garden (like one you can't see the end of), houses, trees etc are going to reduce the air flow a lot.
Also, although I said in another posting that their noise wasn't that bad except close up, I did mean a few hundred metres, not next to your bedroom. Triple glazing however will keep out most of the noise, and of course save energy.
Although you may get planning permission from some daft artsgrad in the local council, doesn't mean that your neighbours will take well to it.
Also these things aren't safe. At all.
They are energy sources. All energy sources are dangerous.
In this case you have a huge whirling blade that is constantly out in bad weather.
You will need liability insurance for when the damn thing breaks down and some poor soul has to climb up and fix it. You've got a dynamo up a long pole. You want to fix that ?
What if he falls down and sues ?
Oh yes, and you will need to store the oil. Oh did the nice empathetic holistic man from the local greens not tell you about lubrication ?
Hint: Homeopathy doesn't work on anything that isn't capable of enjoying a placebo effect. So you need a lot mroe than a tiny drop.
It is not hard at all to anchor this in the ground, with a lump of concrete. Of course it's also easy to get this wrong (how would an untrained person know ?do you know any trained windmill installers ?)
If that fell over, you really don't want it near you.
Oh yes, and now we come to the hard bits.
Housing electrics aren't hard, with dilligent study and this here internet thingie, 6 months from now you can safely be let loose with this.
Of course that's 6 months full time, but you didn't want a job did you ?
Also it doesn't blow all the time. You going to store the electricity ?
Welcome to the world of lead and acid. straight away 50% of your energy is going to be wasted, but it's free right (aside from the cost of equipment, insurance, and training, oh yes and the big hole full of concrete).
There's very little better for storing electricity than lead/acid batteries. Relatively cheap, the set you'll need is not likely to cost more than a thousand quid.
Sadly they have issues that you organic vegan friend didn't know about. (hint: Chakras don't work on suplphate ions).
First is that if you have a fire, these are things that scare firemen. Depending upon their mood they emit various gaseous acids, liquid acids, or just explode for the sheer hell of it. If they're feeling really mean they won't do any of these things. You can't turn batteries off, so if some fireman tries to put it out with water, it doesn't end well. Hint for greens who've struggled this far, water with acid in iit is a good conductor of electricity. Given it's home (or rather the burned out shell of one) you're lucky, in that it's very unlikely that the current passing through water will produce enough hydrogen concentration to create a really cool explosion.
So it's not all gloom and doom.
Oh yes, and lead acid batteries don't really last all that long when used for this sort of application, but they can be recycled quite efficiently.
I could go on, but that's why you don't see any techies like me on the BBC when green issues get discussed. It's all "representatives of the paleeo green alliance who are trying to build awareness"
Buiding mains electrcity in your garden is like building a helicopter there.
Actually a friend of mine did that. No one would go up in it with him though.