8. A Siemens SWT-2.3-82 wind turbine has a maximal power output of 2.3 MW at the rated wind speed of 17.5 m/s. The wind turbine has a rotor diameter of 82.4 meters. Assume an air density of 1.2 kg/m3. (a). What is the power coefficient of this wind turbine? [5 marks] (b). What is the capacity factor if the wind turbine is installed in a location with an average wind speed of 10.8 m/s? Assume the power coefficient is the same at 10.8 m/s and 17.5 m/s. [5 marks]