One thing you should do is actually measure your wind speed with an anemometer, which simply measures the wind speed. When this is connected however to a data logger, you can collect and analyse your average wind speed over a period of time. You would need to measure the wind speed for a period of at least 1 years to get a truly accurate average, as the wind speed not only varies during a year, but you can get "windy" and "calm" years, which can make a significant difference. You can however measure for a much shorter period and correlate your reading with a local weather station.
