tip speed ratio

Tip Speed Ratio, or tsr for short is the relationship between the real wind (as measured by an anemometer) and the 'appearent wind' as seen by the tip of the a blade. If a tip moves at 5 meters per second when the actual wind is moving 1 meter per second that blade would be said to have a tsr of 5.

The tip speed ratio is an important number. It allows you to determine how fast your rotor will turn for any given wind, and if you know the design parameters for the alternator you can predict the amount of power for various windspeeds resulting in a ''power curve'.