The wind speed should be mainly from 5 to 20 m/sec because this range permits the wind turbine to operation. Outside this interval, the wind turbine does not operate. It is also necessary to have historical data relevant to the wind speed for 20 years back. These data are available in certain meteorological web site or you can find measures of a site close to the airport and doing approximations to have suitable values corresponding to the site where it is proposed to install the wind farm.
For the height of the hub, the more it is tall the best is the wind speed. Also, it is better to do economical study to compare the investments, operation and maintenance cost with the electric energy generated by the wind farm. The power curve of the particular wind turbine is needed because for each wind speed, it corresponds to an electrical power. This allows measuring the reliability rate and the net value added. These two parameters give indications about the viability of the projects. The data must be hourly for one year at a certain height. But the wind speed must be corrected to the height of the hub taking into account losses (power electronics, rotor friction, shedding effects....etc.)