A three-blade, 750-kW wind turbine with a blade length of 20m is located where the wind speed statistics for one year (8760 hours) is shown in Fig. 1-20. Calculate the average speed at this location. 2800 Vw (m/s) Hours/year Hours/year 2400 0-3 820 3-6 2400 1720 6-9 2800 9-12 1720 820 750 12-15 750 15-18 220 220 50 18-21 50 3 6 9 12 15 18 21 Vw (m/s) FIGURE 1-20 Statistic of wind speed, Vy, in m/S for one year (8760 hours). Average wind speed formulas: = where Hk is the hours per year that the wind speed is within a specific range