Anemometer and data logger

[Gimley99]

Hi all

I plan to install a 12 volt immersion heater into my hot water cylinder and run it via a car battery which will be charged from a small 12volt turbine mounted on a mast at the end of my garden.
Now the problems. I live on a 1950s housing estate where the house gardens form a largest square surrounded by houses so the wind speed will not be great. My thoughts are if the emersion heater is constantly working it will at least provide a pre-heater function.
Before setting out on the project I want to check the wind speed I can expect. So my question to you lovely people is does anyone know of a low cost anemometer and data logger system I can use to gather the wind speed data I need to be able to design the system?
I already have solar panels and I don't want to mount the turbine on the roof as I have heard they can produce low frequency noise that can be heard in side a building.

Regards Dave