Wind Power

Wind power is produced by using wind generators to harness the kinetic energy of wind. It is gaining worldwide popularity as a large scale energy source, although it still only provides less than one percent of global energy consumption. In order to create enough energy to provide for several people, wind power must be produced at large scale wind farms that are connected to electrical grids. These farms are built in flat, open areas where the wind blows at least 14 miles per hour. Iowa currently has more than 600 wind turbines, producing enough electricity to power 140,000 homes. In order to produce the most possible electricity, the taller the wind turbine must be. Most wind machines being used today are the horizontal-axis type. Horizontal-axis wind machines have blades like airplane propellers that help to slow down the speed of the wind and create a "lift" to turn the blades. The largest wind turbine in the world, located in Hawaii, stands 20 stories tall and has blades the length of a football field. One of the largest wind farms in the U.S. is in Altamont Pass, California. It has more than 900 wind turbines that generate enough electricity to power over 300,000 homes per year. These large commercial size turbines may have a capacity of 5 million watts, or 5 megawatts. Good sites for wind plants are the tops of smooth, rounded hills, open plains or shorelines, and mountain gaps that produce wind funneling.

One large problem with wind turbines is what to do when the wind isn't blowing. During this time, there must be other forms of power generation. Along with this, there have been at least 40 fatalities due to construction, operation, and maintenance of wind turbines, including both workers and members of the public, and other injuries and deaths attributed to the wind power life cycle. Most worker deaths involve falls or becoming caught in machinery while performing maintenance inside turbine housings. Blade failures and falling ice have also accounted for a number of deaths and injuries. Deaths to members of the public include a parachutist colliding with a turbine and small aircraft crashing into support structures. Other public fatalities have been blamed on collisions with transport vehicles and motorists distracted by the sight and shadow flicker of wind turbines along highways.

Wind energy is plentiful, renewable, widely distributed, clean, and reduces greenhouse gas emissions when it displaces fossil-fuel-derived electricity. The amount of power transferred to a wind turbine is directly proportional to the density of the air, the area swept out by the rotor, and the cube of the wind speed. Because so much power is generated by higher wind speed, much of the energy comes in short bursts. The consequence is that wind energy does not have as consistent an output as fuel-fired power plants; utilities that use wind power must provide backup generation for times that the wind is weak. A different solution is to store the large amount of power generated in the bursts to use it later. There are many thousands of wind turbines operating, with a total capacity of 73,904 MW of which wind power in Europe accounts for 65% (2006). The United States ranks third in the world in wind power capacity. Wind power was the most rapidly growing means of alternative electricity generation at the turn of the 21st century. World wind generation capacity more than quadrupled between 2000 and 2006. 81% of wind power installations are in the US and Europe.Wind power consumes no fuel for continuing operation, and has no emissions directly related to electricity production. Operation does not produce carbon dioxide, sulfur dioxide, particulate matter, or any other type of air pollution, as do fossil fuel power sources (wilkipedia on Wind Power).