What is Wind Energy?
Once called windmills, the technology used to harness the power of wind has advanced significantly over the past ten years, with the United States increasing its wind power capacity 30% year over year. Wind turbines, as they are now called, collect and convert the kinetic energy that wind produces into electricity to help power the grid.
Wind energy is actually a byproduct of the sun. The sun’s uneven heating of the atmosphere, the earth’s irregular surfaces (mountains and valleys), and the planet's revolution around the sun all combine to create wind. Since wind is in plentiful supply, it’s a resource for as long as the sun’s rays heat the planet.
In addition, wind energy adds jobs to communities around the country. Currently, there are utility-scale wind plants in 41 states that have created more than 100,000 jobs for Americans.
Learn more about wind, from how a wind turbine works, to research in the field of wind energy.
This aerial view of a wind turbine 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.
How does wind work?
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.
Types of Wind Turbines
Horizontal-axis wind turbines are what many people picture when thinking of wind turbines.
Most commonly, they have three blades and operate "upwind," with the turbine pivoting at the top of the tower so the blades face into the wind.
These turbines are omnidirectional, meaning they don’t need to be adjusted to point into the wind to operate.
Additionally, wind turbines can be built on land or offshore in large bodies of water like oceans and lakes. Modern wind turbines can be categorized by where they are installed and how they are connected to the grid:
Land-based wind turbines range in size from 100 kilowatts to as large as several megawatts.
Larger wind turbines are more cost effective and are grouped together into wind plants, which provide bulk power to the electrical grid.
Primus WindPower | 44231When wind turbines of any size are installed on the "customer" side of the electric meter, or are installed at or near the place where the energy they produce will be used, they're called "distributed” wind.
Many turbines used in distributed applications are small wind turbines. Single small wind turbines—below 100 kilowatts—are typically used for residential, agricultural, and small commercial and industrial applications.
Small turbines can be used in hybrid energy systems with other distributed energy resources, such as microgrids powered by diesel generators, batteries, and photovoltaics.
Offshore wind turbines tend to be massive, and taller than the Statue of Liberty.
They do not have the same transportation challenges of land-based wind installations, as the large components can be transported on ships instead of on roads.
These turbines are able to capture powerful ocean winds and generate vast amounts of energy.
Learn more about land-based wind, distributed wind, and offshore wind.
Benefits of Wind
Wind energy offers many advantages, which explains why it's one of the fastest-growing energy sources in the world. To further expand wind energy’s capabilities and community benefits, researchers are working to address technical and socio-economic challenges.
History of Wind Energy
Through history, the use of wind power has waxed and waned, from the use of windmills in centuries past to high tech wind turbines on wind farms today, and nowhere in history is that more evident than in the last century and a half. Read on to discover many of the advances that wind power has made over this period of time. See the timeline.
DOE Accomplishments in Wind Energy
The U.S. Department of Energy has been integral to the advancement of wind energy in the United States. Below are a series of case studies that highlight DOE’s historic contributions to wind energy.
- Smart Transmission Tools Modernize America’s Power Grid
- Exploring Wind Energy’s Impacts on Wildlife
- Airfoils, Where the Turbine Meets the Wind
- How Wind Energy Became Integral to the Modern Grid
- Bends, Twists, and Flat Edges Change the Game for Wind Energy
- Modeling the Future of Wind Energy
- Public–Private Collaboration Paves the Way for Commercial Wind Power Growth
- From 1970s Pioneers to Today’s Wind Industry, Aerospace Researchers Championed Wind Energy
- International Agreements on Wind Energy Standards
- Blade and Drivetrain Testing Advance Wind Turbine Efficiency and Reliability