The average wind speed at a proposed HAWT wind farm site is 12.5 m/s. The power coefficient of each wind turbine is predicted to be 0.41, and the combined efficiency of the gearbox and generator is 92 percent. Each wind turbine must produce 2.5 MW of electrical power when the wind blows at 12.5 m/s. 

(a) Calculate the required diameter of each turbine disk. Take the average air density to be ρ = 1.2 kg/m³. 

(b) If 30 such turbines are built on the site and an average home in the area consumes approximately 1.5 kW of electrical power, estimate how many homes can be powered by this wind farm, assuming an additional efficiency of 96 percent to account for the powerline losses.