We live on a windy location. To estimate what we could generate, I installed a wind meter.
The Energy estimate is calculated as follows:
The "cut in" speed of 2 m/s is substracted from the windspeed. Below the cut in speed no energy is generated.
The turbine generates its design power at the "rated speed" of 11 m/s. Above the rated speed, the power stays constant, as the turbine will start to furl.
The energy depends on the 3rd power of the wind speed. So, halfway the speed range (at 6.5 ms) the turbine generates only 12.5% of its "rated" power".
The masurements are made every 5 seconds and averaged. Every hour, the averages are entered in the database of the ISP.