Wind 101: the basics of wind energy
Learn how wind is used to generate electricity, how it got so affordable, and how it fits into the modern U.S. power grid. These are the wind energy basics. For top facts about wind energy, visit Wind Energy in the United States.
Wind power is the ability to make electricity using the air flows that occur naturally in the earth’s atmosphere. Wind turbine blades capture kinetic energy from the wind and turn it into mechanical energy, spinning a generator that creates electricity.
Wind is a type of renewable energy, and there are three major types of wind power.
- Utility-scale wind: wind turbines larger than 100 kilowatts with electricity delivered to the power grid and distributed to the end user by electric utilities or power system operators;
- Distributed or "small" wind: use turbines of 100 kilowatts or smaller to directly power a home, farm or small business as it primary use;
- Offshore wind: wind turbines erected in large bodies of water, usually on the continental shelf.
When wind blows past a turbine, the blades capture the kinetic energy and rotate, turning it into mechanical energy. This rotation turns an internal shaft connected to a gearbox, which increases the speed of rotation by a factor of 100. That spins a generator to produce the electricity.
Typically standing at least 80 meters tall, tubular steel towers support a hub with three attached blades and a “nacelle,” which houses the shaft, gearbox, generator, and controls. Wind measurements are collected to automatically rotate the turbine to face the strongest wind and angle or "pitch" its blades to optimize the energy captured.
A typical modern turbine generates usable amounts of power over 90 percent of the time. It will start to generate electricity when wind speeds reach 6 -9 miles per hour (or 3 – 4 meters per second), and cut off at about 45 miles an hour (or 20 meters per second) to prevent equipment damage.
Over the course of a year, modern turbines can reach more than 40 percent of their rated maximum capacity; that is as good as or better than most other forms of electric generation such as natural gas plants, which also don’t run 24/7.
The terms “wind mill” and “wind turbine” are sometimes used interchangeably, but there are important differences. Windmills generate mechanical energy, but they do not generate electricity. People started using windmills centuries ago to grind grain, pump water, and do other work.
Today's wind turbine is a highly evolved machine with more than 8,000 parts. Modern wind turbines harness wind's kinetic energy and convert it into electricity. Learn more about the history of wind energy.
Wind turbines often stand together in a windy area that has been through a robust development process, in an interconnected group called a wind project or wind farm, which functions as a single power plant that puts electricity onto the grid.
The turbines in a wind farm are connected so the electricity can travel from the wind farm to the power grid. Once wind energy is on the main power grid, electric utilities or power operators will deliver the electricity where it is needed. Smaller transmission lines called distribution lines will collect the electricity generated at the wind project site and transport it to larger "network" transmission lines where the electricity can travel across long distances to the locations where it is needed, when finally the smaller "distribution lines" deliver electricity directly to your town and home. Learn more about transmission.
The current estimate of U.S. wind energy potential is 10 times greater than total U.S. electricity consumption. America’s powerful natural resource varies by region and topography. Companies develop wind energy projects by seeking out the areas with the strongest wind resource. They also review other critical factors like access to land, access to the transmission lines, ability to sell the electricity, and public engagement other significant development factors.
- Once a site is identified, a developer will conduct wind resource assessment, siting and permitting, transmission studies over a period of several years. The majority of wind projects are located on private land, where the developer leases the land from the original landowner providing lease payments.
- After early stages of development, a developer will seek out a contract with a purchaser of electricity, raise capital from the finance markets, order wind turbines, and hire a specialized construction company to build the project.
- Finally, once a project is built and delivering electricity to the power grid, a project owner or operator will maintain the project for its 20 to 30 year life.
Wind energy is a clean, renewable form of energy that has many pros:
- Wind power pumps billions of dollars into our economy every year, particularly into rural areas where over 99 percent of wind farms are located; 71 percent of those reside in low-income counties. Over the last decade, the industry has invested an average of over $14 billion annually in new wind projects.
- Wind energy supported over 100,000 well-paying American jobs in 2016, including 25,000 manufacturing jobs. The fastest-growing job in America is “wind turbine technician,” according to the Department of Labor.
- Wind energy is a drought-resistant cash crop that farmers and ranchers rely on to make a living and keep their land in the family. During 2016, U.S. wind projects paid at least $245 million in lease payments to landowners. The local taxes they pay help rural communities afford teachers, ambulances, and roads.
- Wind power produced $7.4 billion a year in public health savings in 2016 by cutting pollutants that create smog and trigger asthma attacks and other lung diseases, according to the Harvard School of Public Health.
- Transitioning to clean energy protects “all people from the harm of air pollution,” according to the American Lung Association. Its Healthy Air Campaign works for “reforms to transmission and distribution policies that will encourage the expansion delivery of clean, renewable, non-combustion energy resources” such as wind energy.