Wind Farms A wind farm is a large group of wind turbines The turbines work together to produce power for communities and businesses The rows of wind turbines are called arrays The first wind farm was built in 1980 in New Hampshire It had 20 wind turbines Today wind farms are much larger The biggest wind farm in the world is the Alta Wind Energy Center in California It features more than 480 turbines Wind turbines sit on tall towers They have two or three blades at the top The wind causes these blades to spin They turn the energy of the wind into electricity This is wind power What Is Wind Power Wind energy is in part a form of a solar energy The sun is always heating Earth’s ground and air Wind exists because of the temperature changes this creates Some areas heat up Others cool down Warm air is less dense than cold air so it rises This movement helps create wind 6
Workers may have to dangle high in the air when repairing large wind turbine blades
The Earth spins on its axis as it orbits the sun This spinning motion causes air to move Wind turbines Big and Tall Modern industrial wind turbines can be hundreds of feet tall These turbines reach high above the ground Up there the wind is stronger The turbines of the future may reach even higher Tall turbines are often tubes of steel This shape and material makes them strong yet light take advantage of all this motion Wind propels the blades of a wind turbine to make electricity Benefits and Challenges Wind energy is one of the fastest-growing energy sources There are many reasons for this Wind power is clean Unlike coal and oil it does not pollute when it is used Wind is also easily available In some places on the globe the wind blows almost all the time In addition wind turbines do not take up much space They can be built on a corner of a farm and still leave lots of land for planting 8
Wind Speed m s m s 10 5 Wind Speed 10 0 9 5 9 0 10 5 8 5 10 0 8 0 9 5 9 0 7 5 8 5 7 0 8 0 6 5 7 5 6 0 7 0 6 5 5 5 6 0 5 0 5 5 4 5 5 0 4 5 4 0 4 0 4 0 4 0 Where the Wind Blows This map shows the average wind speeds across the United States at 262 feet 80 m above the ground Which areas have the strongest winds Which areas have the least wind What are the winds like where you live Wind energy is a promising technology but it faces challenges One challenge is bringing electricity from windy places to cities Some of the windiest areas are far from the urban areas that use lots of electricity In addition setting up wind turbines can be very expensive The wind is free but turbines are not Also some people do not like the sound or look 9
