For domestic small scale wind turbines to be effective, the recommended average annual wind speed at a height of 10 m above ground is 11 mph (5 metres per second). In Alton, the mean annual wind speed is 9.6 mph (4.3 metres per second). It may be possible to install turbines on the higher ground surrounding the town, provided other factors such as buildings and trees do not interfere.
Costs vary from around £3,000 for a 1 kW system to anything from £15,000 to £40,000 for pole mounted 2.5 kW or 6kW systems. Savings for a 6kW system are of the order of £500 to £750 per year on your electricity bill.
You should check with your local planning authority whether permission is required for installing a wind turbine in your property.
Additional resources:
EST Wind turbines.