Wind Turbine - A wind turbine is a machine that converts kinetic energy from the wind into electricity. The blades of a wind turbine turn between 13 and 20 revolutions per minute, depending on their technology, at a constant or variable velocity, where the velocity of the rotor varies in relation to the velocity of the wind in order to reach a greater efficiency. Wind turbines have an average life of over 25 years. Rapid evolution of wind technology has lead to an increase in the durability of wind turbines.