A New England machinist obtained the first American windmill patent in 1854. Until 1920, wind power was a major form of energy in the western United States, essential to development. Prior to 1920, thousands of windmills were put up across the Great Plains and helped settle the West. Windmills were used to bring water to farms and railroads. The wind energy potential of the United States was measured in potential kilowatt hours in 1991, factoring in environmental and land effects. North Dakota had the highest potential and Maine was 19th. Wind energy is the fastest growing source of power in the world today. When large scale wind farms were introduced in the 1970s, the cost of producing power with windmills was very high. This perception continues, but the cost has shrunk from 38 cents per kilowatt hour to 4 to 6 cents per kilowatt hour, making wind power competitive. The wind turbines have improved greatly since 1981, as the first wind turbines produced 25 kilowatts, while new versions can power up to one megawatt. The towers in 1981 were 100 feet or less, but today they can be up to 200 feet, decreasing surface interference and lowering cost. Wind farms are now economically viable because of these technological improvements. However, the cost of developing wind farms is very high initially. In fact, 80 % of the cost of producing wind power is in building the facilities. Large banks do not like to pay for such large investments up front, slowing the development of wind power. But three wind farms have been built in Texas in the last two years, and another is in development in Oklahoma. A web site on Danish wind power states that a turbine produces eighty times its initial cost over a twenty year life span, meaning that its cost is recovered in only two to three months. In Europe more than 17,000 megawatts of wind power were on line as of January 2002, covering the average domestic electricity consumption of ten million households.
