Mount Zion, where I live, must be one of the windiest places around Wrexham. The house is right on top of a hill at over 250 metres above sea level and visitors often comment about how strong the wind is up here (on some days, it makes opening a car door difficult and opening the doors on both sides of the car simultaneously a very bad idea). But it isn't windy all the time - today there's just a light breeze and there are many days, especially in summer, where there is quite a difference between the wind power at the front and the back of the house, where the wind whips across the back gardens towards Hope Mountain, while the front area can be relatively still.
I read this article "Why micro wind turbines don't work" and used the links to work out the wind power at this location (I'm not planning to put a turbine with 1.75metre-long blades up at the end of my garden or on my roof! Even that would be a bit too big for up here IMHO). Remember, compared with most places and certainly most urban situations, it is very windy where I live. The result? At 10 metres above ground level, it seems the average wind speed is 4.7 metres per second (click here to read the notes on the windspeed database, which apparently estimates wind speed based on topography, but without allowing for mountain or valley breezes). That puts the average wind speed at something similar to those at the BBC Ethical Man's home in London i.e. not viable.
My point is, if it isn't windy enough for a domestic wind turbine here, where would be?
I'll wait till I can afford those solar PVs...