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Answers
The Power of Wind
Wind turbines harness the wind—a clean, free, and widely available renewable energy source—to generate electric power. This page offers a text version of the interactive animation: How a Wind Turbine Works.
How a Wind Turbine Works
A wind turbine turns wind energy into electricity using the aerodynamic force from the rotor blades, which work like an airplane wing or helicopter rotor blade. When wind flows across the blade, the air pressure on one side of the blade decreases. The difference in air pressure across the two sides of the blade creates both lift and drag. The force of the lift is stronger than the drag and this causes the rotor to spin. The rotor connects to the generator, either directly (if it's a direct drive turbine) or through a shaft and a series of gears (a gearbox) that speed up the rotation and allow for a physically smaller generator. This translation of aerodynamic force to rotation of a generator creates electricity.
How a Wind Plant Works
Wind power plants produce electricity by having an array of wind turbines in the same location. The placement of a wind power plant is impacted by factors such as wind conditions, the surrounding terrain, access to electric transmission, and other siting considerations. In a utility-scale wind plant, each turbine generates electricity which runs to a substation where it then transfers to the grid where it powers our communities.
Screen capture of the wind plant view of the How Wind Turbines work animation.
Transmission
Transmission lines carry electricity at high voltages over long distances from wind turbines and other energy generators to areas where that energy is needed.
Still frame of an illustrated transmission tower highlighted in in an animation window.
Transformers
Transformers receive AC (alternating current) electricity at one voltage and increase or decrease the voltage to deliver the electricity as needed. A wind power plant will use a step-up transformer to increase the voltage (thus reducing the required current), which decreases the power losses that happen when transmitting large amounts of current over long distances with transmission lines. When electricity reaches a community, transformers reduce the voltage to make it safe and useable by buildings and homes in that community.
Still frame of a wind power illustration in both land-based and offshore contexts with the transformers highlighted in an animation window.
Substation
A substation links the transmission system to the distribution system that delivers electricity to the community. Within the substation, transformers convert electricity from high voltages to lower voltages which can then be delivered safely to electricity consumers.
Still frame of an illustrated substation highlighted in an animation window.
Wind Turbine Tower
Made from tubular steel, the tower supports the structure of the turbine. Towers usually come in three sections and are assembled on-site. Because wind speed increases with height, taller towers enable turbines to capture more energy and generate more electricity. Winds at elevations of 30 meters (roughly 100 feet) or higher are also less turbulent.
Still frame of an illustrated turbine highlighting the turbine’s tower in an animation window.
Wind Direction
Determines the design of the turbine. Upwind turbines—like the one shown here—face into the wind while downwind turbines face away. Most utility-scale land-based wind turbines are upwind turbines.
Still frame of an illustrated wind turbine with a highlighted arrow showing wind direction in an animation window.
Wind Vane
The wind vane measures wind direction and communicates with the yaw drive to orient the turbine properly with respect to the wind.
Still frame of an illustrated turbine highlighting a wind vane in an animation window.
Anemometer
The anemometer measures wind speed and transmits wind speed data to the controller.
Still frame of an illustrated anemometer highlighted in an animation window.
Blades
Most turbines have three blades which are made mostly of fiberglass. Turbine blades vary in size, but a typical modern land-based wind turbine has blades of over 170 feet (52 meters). The largest turbine is GE's Haliade-X offshore wind turbine, with blades 351 feet long (107 meters) – about the same length as a football field. When wind flows across the blade, the air pressure on one side of the blade decreases. The difference in air pressure across the two sides of the blade creates both lift and drag. The force of the lift is stronger than the drag and this causes the rotor to spin.