There are several wind turbines classified according to size, construction and function. Very small turbines used to charge batteries or feeding to the grid with a rotor diameter up to 4m and nominal power rating of up to 3kW fits in with the category of micro wind turbines. 3kW -20kW machines are in the small wind turbines category. This photo is of a 10Kw Hummer which sit’s on a ten meter pole designed and engineered in New Zealand. The blades each measure 3 meters long.