sentences:  Wind turbines with two blades are manufactured by Windflow Technology, Mingyang Wind Power, GC China Turbine Corp and Nordic Windpower,.The NASA wind turbines (1975-1996) each had 2-blade rotors, producing the same energy at lower cost than three-blade rotor designs.Nearly all wind turbines place the rotor in front of the nacelle when the wind is blowing (upwind design).