It is desired to design a wind turbine that will output 2MW of peak electrical power at a location where the average wind speed is 10 m/s and the average ambient conditions are 85 kPa and 5 ?C. What should the rotor blade length be if the aerodynamic efficiency of the blades is 50%, the gearbox has a power transmission efficiency of 85%, and the electrical generator has efficiency of 92% ? Since the purpose of the exercise is to utilize the concept of efficiency, be sure to carefully define the three efficiencies in terms of variables and carefully show how they were used. What is the overall efficiency of the wind turbine?