The following specification for two types of HAWT turbines are supplied by the manufacturers. (i) (ii) Item Rotor diameter Power coefficient Gearbox efficiency Generator efficiency Capital cost Turbine A 25 m 38 90 98 $99,000 Maintenance cost/year $4,000 Turbine B 30 m 35 88 95 $103,000 $4,000 Tabulate the power performance (in kW) of each turbine for the wind speed of 4-10 m/s in step of 2 m/s interval. Density of air is assumed to be 1.23 kg/m. [6 marks] Assume that the annual wind availability at the site is 2000 hours for an average wind speed of 6 m/s. Evaluate which turbine is more economical to be employed. Assume life expectancy for each to be 20 years and the unit cost of power to be 6 cents per kWh to remain constant.