Anything that moves has kinetic energy, and scientists and engineers are using the wind’s kinetic energy to generate electricity. Wind energy, or wind power, is created using a wind turbine, a device that channels the power of the wind to generate electricity.
The wind blows the blades of the turbine, which are attached to a rotor. The rotor then spins a generator to create electricity. There are two types of wind turbines: the horizontal-axis wind turbines (HAWTs) and vertical-axis wind turbines (VAWTs). HAWTs are the most common type of wind turbine. They usually have two or three long, thin blades that look like an airplane propeller. The blades are positioned so that they face directly into the wind. VAWTs have shorter, wider curved blades that resemble the beaters used in an electric mixer.
Small, individual wind turbines can produce 100 kilowatts of power, enough to power a home. Small wind turbines are also used for places like water pumping stations. Slightly larger wind turbines sit on towers that are as tall as 80 meters (260 feet) and have rotor blades that extend approximately 40 meters (130 feet) long. These turbines can generate 1.8 megawatts of power. Even larger wind turbines can be found perched on towers that stand 240 meters (787 feet) tall have rotor blades more than 162 meters (531 feet) long. These large turbines can generate anywhere from 4.8 to 9.5 megawatts of power.
Once the electricity is generated, it can be used, connected to the electrical grid, or stored for future use. The United States Department of Energy is working with the National Laboratories to develop and improve technologies, such as batteries and pumped-storage hydropower so that they can be used to store excess wind energy. Companies like General Electric install batteries along with their wind turbines so that as the electricity is generated from wind energy, it can be stored right away.
According to the U.S. Geological Survey, there are 57,000 wind turbines in the United States, both on land and offshore. Wind turbines can be standalone structures, or they can be clustered together in what is known as a wind farm. While one turbine can generate enough electricity to support the energy needs of a single home, a wind farm can generate far more electricity, enough to power thousands of homes. Wind farms are usually located on top of a mountain or in an otherwise windy place in order to take advantage of natural winds.
The largest offshore wind farm in the world is called the Walney Extension. This wind farm is located in the Irish Sea approximately 19 kilometers (11 miles) west of the northwest coast of England. The Walney Extension covers a massive area of 149 square kilometers (56 square miles), which makes the wind farm bigger than the city of San Francisco, California, or the island of Manhattan in New York. The grid of 87 wind turbines stands 195 meters (640 feet) tall, making these offshore wind turbines some of the largest wind turbines in the world. The Walney Extension has the potential to generate 659 megawatts of power, which is enough to supply 600,000 homes in the United Kingdom with electricity.