Small scale wind turbines use the wind's lift forces to turn aerodynamic blades that turn a rotor which creates electricity.
Individual turbines vary in size and power output from a few hundred watts to 2 or 3 megawatts. As a guide, a typical domestic system would be 2.5 to 6 kilowatts, depending on the location and size of the home.
Please note that the electricity generated at any one time by a wind turbine is highly dependent on the speed and direction of the wind.
If you are in any doubt about the suitability of your proposed site, please consult a suitably qualified professional.
For more on how wind turbines work, suitable siting, connection to the grid, costs, maintenance and other considerations see the Energy Saving Trust information page.