howwindturbineswork

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1、How Wind Turbines WorkWind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earths surface, and rotation of the earth. Wind flow patterns are modified by the earths terrain, bodies of water, and vegetation. Humans use this wind

2、 flow, or motion energy, for many purposes: sailing, flying a kite, and even generating electricity.The terms wind energy or wind power describe the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical pow

3、er. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity.So how do wind turbines make electricity? Simply stated, a wind turbine works the opposite of a fan. Instead of using electricity to ma

4、ke wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. Take a look inside a wind turbine to see the various parts. View the wind turbine animation to see how a wind turbine works.This aerial

5、 view of a wind power plant shows how a group of wind turbines can make electricity for the utility grid. The electricity is sent through transmission and distribution lines to homes, businesses, schools, and so on.Learn more about wind energy technology: Types of Wind Turbines Sizes of Wind Turbine

6、s Inside the Wind TurbineMany wind farms have sprung up in the Midwest in recent years, generating power for utilities. Farmers benefit by receiving land lease payments from wind energy project developers.Types of Wind TurbinesModern wind turbines fall into two basic groups: the horizontal-axis vari

7、ety, as shown in the photo, and the vertical-axis design, like the eggbeater-style Darrieus model, named after its French inventor.Horizontal-axis wind turbines typically either have two or three blades. These three-bladed wind turbines are operated upwind, with the blades facing into the wind.GE Wi

8、nd Energys 3.6 megawatt wind turbine is one of the largest prototypes ever erected. Larger wind turbines are more efficient and cost effective.Sizes of Wind TurbinesUtility-scale turbines range in size from 100 kilowatts to as large as several megawatts. Larger turbines are grouped together into win

9、d farms, which provide bulk power to the electrical grid.Single small turbines, below 100 kilowatts, are used for homes, telecommunications dishes, or water pumping. Small turbines are sometimes used in connection with diesel generators, batteries, and photovoltaic systems. These systems are called

10、hybrid wind systems and are typically used in remote, off-grid locations, where a connection to the utility grid is not available.Inside the Wind TurbineAnemometer: Measures the wind speed and transmits wind speed data to the controller. Blades: Most turbines have either two or three blades. Wind bl

11、owing over the blades causes the blades to lift and rotate. Brake: A disc brake, which can be applied mechanically, electrically, or hydraulically to stop the rotor in emergencies. Controller: The controller starts up the machine at wind speeds of about 8 to 16 miles per hour (mph) and shuts off the

12、 machine at about 55 mph. Turbines do not operate at wind speeds above about 55 mph because they might be damaged by the high winds. Gear box: Gears connect the low-speed shaft to the high-speed shaft and increase the rotational speeds from about 30 to 60 rotations per minute (rpm) to about 1000 to

13、1800 rpm, the rotational speed required by most generators to produce electricity. The gear box is a costly (and heavy) part of the wind turbine and engineers are exploring direct-drive generators that operate at lower rotational speeds and dont need gear boxes. Generator: Usually an off-the-shelf i

14、nduction generator that produces 60-cycle AC electricity. High-speed shaft: Drives the generator. Low-speed shaft: The rotor turns the low-speed shaft at about 30 to 60 rotations per minute. Nacelle: The nacelle sits atop the tower and contains the gear box, low- and high-speed shafts, generator, co

15、ntroller, and brake. Some nacelles are large enough for a helicopter to land on. Pitch: Blades are turned, or pitched, out of the wind to control the rotor speed and keep the rotor from turning in winds that are too high or too low to produce electricity. Rotor: The blades and the hub together are c

16、alled the rotor. Tower: Towers are made from tubular steel (shown here), concrete, or steel lattice. Because wind speed increases with height, taller towers enable turbines to capture more energy and generate more electricity. Wind direction: This is an upwind turbine, so-called because it operates

17、facing into the wind. Other turbines are designed to run downwind, facing away from the wind. Wind vane: Measures wind direction and communicates with the yaw drive to orient the turbine properly with respect to the wind. Yaw drive: Upwind turbines face into the wind; the yaw drive is used to keep t

18、he rotor facing into the wind as the wind direction changes. Downwind turbines dont require a yaw drive, the wind blows the rotor downwind. Yaw motor: Powers the yaw drive.Printable Version Skip footer navigation to end of page. Wind and Hydropower Technologies Program Home | EERE Home | U.S. Department of EnergyWebmaster | Web Site Policies | Security & Privacy | USA.gov Content Last Updated: 11/30/2006