Wind speeds are calculated at 80 m, the hub height 
                              of modern, 77-m diameter, 1500 kW turbines. Since 
                              relatively few observations are available at 80 
                              m, the Least Square extrapolation technique is utilized 
                              and revised here to obtain estimates of wind speeds 
                              at 80 m given observed wind speeds at 10 m (widely 
                              available) and a network of sounding stations. 
                            Tower data from the Kennedy Space Center (Florida) 
                              were used to validate the results. Globally, ~13% 
                              of all reporting stations experience annual mean 
                              wind speeds ≥ 6.9 m/s at 80 m (i.e., wind 
                              power class 3 or greater) and can therefore be considered 
                              suitable for low-cost wind power generation. This 
                              estimate is believed to be conservative. 
                            Of all continents, North America has the largest 
                              number of stations in class 3 (453).