Most wind turbines in the United States were designed for medium wind environments, according to data collected in the U.S. Energy Information Administration’s (EIA) Annual Electric Generator Report. Wind design classes, as defined by the International Electrotechnical Commission (IEC), range from Class 1 (high wind) to Class 4 (very low wind). Many of the earliest wind projects in the United States were constructed in California using Class 1 turbines. These earlier projects required high wind speeds to generate sufficient wind-powered electricity to offset relatively high installation costs. Technological ... (full story)