Wind power uses wind energy to create energy that can be used for work. In the past, wind power was used with sails, windmills, and windpumps, but today it is mainly used to make electricity. This text focuses only on wind power for electricity. Most electricity from wind is now made using wind turbines, which are often grouped into wind farms and connected to the electrical grid.

In 2024, wind power provided about 2,500 TWh of electricity, which was more than 8% of the world’s total electricity. During 2021, about 100 GW of new wind power was added, mostly in China and the United States. This caused global wind power capacity to exceed 800 GW. In 2024, 30 countries produced more than one-tenth of their electricity from wind power. Wind electricity generation has grown nearly three times since 2015. To help reach goals set by the Paris Agreement to reduce climate change, experts say wind power should grow much faster—by more than 1% of electricity production each year.

Wind power is a renewable and sustainable energy source. It has a smaller effect on the environment compared to burning fossil fuels. Because wind power is not always available, it needs storage or other energy sources that can provide power when needed. Onshore wind farms have a larger visual effect on the landscape compared to most other power plants for the same amount of energy produced. Offshore wind farms have less visual impact and can produce more electricity on average, but they are usually more expensive. About 10% of new wind power installations in 2024 were offshore.

Wind power is one of the least expensive ways to produce electricity. In many places, new onshore wind farms cost less to build than new coal or gas power plants.

Areas near the higher northern and southern latitudes have the greatest potential for wind power. In most regions, wind power produces more electricity at night and in winter, when solar power is less available. This makes wind and solar power a good combination for many countries.

Wind energy resources

Wind is the movement of air in Earth's atmosphere. In one second, the amount of air that moves through a certain area, called A, is equal to A multiplied by the wind speed, v. If the air has a density, represented by ρ, the rate at which air moves through that area is calculated as ρ multiplied by A and v. The energy transferred by this moving air each second, called power, is equal to one-half of ρ multiplied by A and v cubed. This means wind power is directly connected to the cube of wind speed. If wind speed doubles, the available power increases eight times. A wind speed increase of about 2.15 times raises wind power by a factor of 10.

From 1979 to 2010, the average kinetic energy in Earth's wind was about 1.50 megajoules per square meter globally, with 1.31 megajoules per square meter in the Northern Hemisphere and 1.70 megajoules per square meter in the Southern Hemisphere. The atmosphere functions like a heat engine, absorbing heat in warm areas and releasing it in cooler areas. This process generates wind energy at a rate of 2.46 watts per square meter, helping to keep air moving despite friction.

Wind power potential can be estimated worldwide, by region, or for specific locations through wind resource assessments. The Global Wind Atlas, created by the Technical University of Denmark and the World Bank, provides a worldwide analysis of wind power potential. Unlike traditional atlases that show average wind speed and power density over many years, tools like Renewables.ninja offer detailed, hour-by-hour simulations of wind speed and turbine power output. More precise, location-specific data can be obtained from specialized companies, and larger wind energy companies often use their own models for analysis.

The total wind energy that can be used economically is much greater than all current human energy use combined. Wind strength varies, and an average wind speed for a location does not alone show how much energy a wind turbine could generate there.

To evaluate possible wind power sites, a probability distribution function is often used to describe wind speed patterns. Different areas have different wind speed patterns. The Weibull model closely matches actual wind speed measurements at many locations. The Weibull factor is often near 2, so the Rayleigh distribution, a simpler model, is sometimes used instead.

Wind farms

A wind farm is a collection of wind turbines located in the same area. A large wind farm may include hundreds of individual wind turbines spread across a large area. The land between the turbines can sometimes be used for farming or other activities. Wind farms can also be built in the ocean. Most large wind turbines have a similar design: a horizontal-axis turbine with three blades, connected to a nacelle on top of a tall tower.

In a wind farm, the turbines are connected through a power collection system that uses medium voltage electricity (often 34.5 kV) and a communication network. In fully developed wind farms, turbines are placed at least 7 times the rotor diameter apart. At a substation, the medium-voltage electricity is increased to a higher voltage using a transformer, allowing it to connect to the main power transmission system.

Modern wind turbines often use variable-speed generators paired with power converters to help connect to the electrical grid and handle power fluctuations. These turbines may use either partially or fully scaled converters, depending on the type of generator used, such as doubly fed machines, squirrel-cage induction generators, or synchronous generators. Some wind farms can restart power systems without external help, a process called black start, which is being developed in places like Iowa.

Transmission system operators provide wind farm developers with a grid code that outlines rules for connecting to the power grid. This includes requirements for power factor, frequency stability, and how turbines behave during electrical system problems.

Offshore wind farms are built in large bodies of water, such as the sea. These locations often have stronger and more consistent winds, which can produce more energy and have less visual impact than land-based farms. However, building and maintaining offshore wind farms is more expensive.

As of November 2021, the Hornsea Wind Farm in the United Kingdom is the largest offshore wind farm in the world, with a capacity of 1,218 MW.

Offshore wind farms near the coast may use alternating current (AC) for power transmission, while those farther from shore may use high-voltage direct current (HVDC).

Wind power resources are not always near areas with many people. As power lines get longer, more energy is lost during transmission. This makes it harder to move large amounts of electricity over long distances.

When the power grid cannot handle the electricity produced by wind farms, the farms must reduce their output or stop entirely, a process called curtailment. This limits renewable energy production but helps avoid overloading the grid or disrupting service.

A major challenge for wind power is building new transmission lines to move electricity from remote areas with strong winds to places where people need more power. Existing lines in remote areas may not be designed for large energy transfers. In some regions, strong winds may not occur when electricity demand is highest. A possible future solution is to connect distant areas using a high-voltage direct current (HVDC) super grid.

Wind power capacity and production

In 2024, wind power provided more than 2,494 terawatt-hours of electricity, which was 8.1% of the world's total electricity. To help meet the goals of the Paris Agreement, which aims to limit climate change, experts say wind power must grow much faster than it is now—by more than 1% of total electricity generation each year. However, the growth of wind power is slowed by financial support given to fossil fuels.

The actual electricity a wind farm can produce is calculated by multiplying its maximum possible output (called nameplate capacity) by the capacity factor. The capacity factor depends on the equipment and location. For wind farms, the capacity factor is usually between 35% and 44%.

Wind speed changes constantly, so a wind farm’s yearly electricity production is always less than the total nameplate capacity multiplied by the number of hours in a year. The ratio of actual yearly production to this maximum possible output is called the capacity factor. Some locations have online data that can be used to calculate the capacity factor.

Wind energy penetration refers to the share of electricity produced by wind compared to all electricity generated. In 2021, wind power provided nearly 7% of the world’s electricity, up from 3.5% in 2015. There is no agreed-upon maximum level of wind energy that a power grid can handle. The limit depends on factors like existing power plants, energy storage, demand management, and grid connections. A connected power grid already includes backup power and transmission lines to handle equipment failures, which can also help balance the variable electricity from wind farms. Studies suggest that up to 20% of a region’s yearly electricity needs could be met with wind power, especially in areas with many wind farms, storage, and strong grid connections.

Wind energy penetration is often measured yearly, but it can also be measured monthly, weekly, or daily. To generate nearly all electricity from wind in a year, a region needs strong connections to other power systems. For example, some wind power in Scotland is sent to the rest of the UK’s grid. On shorter timescales, wind might supply more than 100% of electricity needs, with the extra energy stored, sent to other areas, or temporarily unused. Industries that operate during times of low electricity demand, such as at night, could use this extra energy for tasks like producing metals or hydrogen.

Wind power is not always reliable. During times of low wind, other power sources must replace it. Power grids already handle unexpected outages and daily changes in electricity use, but wind power’s variability happens more often than traditional power sources. This can increase costs for managing power supply and may require more storage, backup power, or grid connections.

Wind energy can vary in output at different times: hourly, daily, or seasonally. While yearly changes are less common, the need to balance electricity supply and demand at any moment makes integrating large amounts of wind power challenging. Wind energy is not always available when needed, which can increase costs for managing power supply and may require more storage, backup power, or grid connections.

Power grids must have extra capacity to handle unexpected changes in electricity supply, such as when wind power drops or fossil fuel plants fail. Large batteries are often used to manage short-term changes in wind power, but car batteries may become more common in the future. Wind power supporters say existing power plants can be restarted quickly to replace wind power during low-wind periods or connected to high-voltage direct current (HVDC) systems.

Combining different types of renewable energy, predicting their output, and pairing them with energy sources that can be turned on or off as needed (like hydropower or natural gas plants) can help create a reliable power system. Real-world examples show that higher levels of renewable energy can be successfully integrated into power grids.

Solar power often works well with wind power. On daily or weekly timescales, sunny weather with little wind and cloudy, windy weather alternate. Seasonally, solar energy is strongest in summer, while wind energy is often stronger in winter. This helps balance the energy supply between the two. Hybrid wind and solar systems are becoming more common.

For any wind turbine, there is an 80% chance its output will change by less than 10% in an hour and a 40% chance it will change by 10% or more in five hours. In summer 2021, wind power in the UK dropped due to unusually low wind speeds over 70 years. In the future, producing green hydrogen during high-wind periods may help store energy for use when wind is less available.

While a single wind turbine’s output can change rapidly with wind speed, connecting many turbines over large areas makes the overall power supply more stable and predictable. Weather forecasts help power networks prepare for expected changes in wind power output.

Experts believe the most reliable low-carbon electricity systems will include a large share of wind power.

Conventional hydroelectric power often works well with wind power. When wind is strong, nearby hydroelectric plants can hold back water. When wind slows, these plants can quickly increase production to balance the supply. This creates a steady power supply with little energy loss.

In areas without suitable water sources, energy storage methods like pumped-storage hydroelectricity, compressed air, or thermal storage can store energy from high-wind periods and release it when needed. The type of storage required depends on how much wind energy is used. Low wind energy use needs daily storage, while high use requires both short- and long-term storage. Storing energy increases its value by allowing it to replace expensive electricity during peak demand times. Although pumped-storage systems are only about 75% efficient and costly to build, their low operating costs and ability to reduce the need for constant base-load power can save fuel and electricity costs.

The energy required to build a wind farm, divided by its total electricity output over its lifetime, is a measure of its efficiency.

Economics

Onshore wind is a low-cost way to make electricity, cheaper than power from coal plants and new gas plants. According to BusinessGreen, wind power became as expensive as traditional energy sources in some parts of Europe during the mid-2000s and in the United States around the same time. As prices for wind power have dropped, it is now believed that wind power reached the same cost level as other energy sources in Europe by 2010 and is expected to do so in the United States by 2016. This is because the cost to build wind power projects is expected to decrease by about 12%. In 2021, the leader of Siemens Gamesa warned that higher demand for wind turbines, along with rising costs for materials like steel, has made it harder for companies to make a profit.

The best places for onshore wind are Northern Eurasia, Canada, parts of the United States, and Patagonia in Argentina. In other areas, solar power or a mix of wind and solar is often cheaper.

Wind power requires a lot of money to build but does not need fuel, so its cost stays more stable compared to energy from fossil fuels like coal or gas. However, the average cost of wind power includes the cost to build turbines and power lines, money borrowed to fund the project, returns for investors, how much electricity the turbines produce each year, and other factors. These costs are spread out over the life of the equipment, which can last more than 20 years. Because these costs depend on many assumptions, different studies may report different numbers.

Even with government help, wind power can lower costs for people by reducing the price of electricity and reducing the need for expensive backup power plants. For example, in Germany, wind power has saved about €5 billion each year for consumers.

The cost of wind power has gone down as turbine technology has improved. Today, wind turbines have longer and lighter blades, better performance, and produce more electricity efficiently. Also, the cost to build and maintain wind projects has decreased over time.

A 2021 study by Lazard found that the average cost of wind power continues to fall, though more slowly now. The study estimated that new wind power costs between $26 and $50 per unit of electricity, compared to $45 to $74 per unit for new gas power. Existing coal power costs about $42 per unit, nuclear power costs $29 per unit, and gas power costs $24 per unit. Offshore wind power costs about $83 per unit. From 2016 to 2021, the cost of wind power dropped by 4% each year, compared to a 10% drop from 2009 to 2021.

Although wind power can now cost the same as traditional energy sources, its value in the electricity market is sometimes lower. This happens because when there is a lot of wind power available, electricity prices can drop because wind power is cheaper to produce. This effect has been seen in several European markets. Wind power plants in areas with many renewable energy sources may struggle to make money because of lower electricity prices.

Turbine prices have dropped in recent years because of more competition, such as government energy auctions, and the removal of subsidies in many countries. In 2021, subsidies were still common for offshore wind, but onshore wind no longer needed them in countries like China, even with low carbon prices, as long as fossil fuel subsidies did not exist.

Businesses are often encouraged to use wind power even if it costs more. For example, companies that care about the environment may pay extra for wind power to help build new wind projects. These companies can then claim they are supporting "green" efforts. Wind projects also help local communities by providing tax payments or income to farmers who allow wind turbines on their land.

The wind energy industry creates jobs during construction and operation. These jobs include building turbines, transporting and installing them, and maintaining them. In 2020, about 1.25 million people were working in wind power.

Small-scale wind power

Small-scale wind power refers to wind systems that can produce up to 50 kilowatts of electricity. Remote communities that usually depend on diesel generators can use wind turbines as an alternative. People may buy these systems to save money by reducing their use of electricity from the main power grid or to lower the amount of pollution they create. For many years, wind turbines have been used in remote areas to generate electricity for homes, often paired with batteries to store energy.

In urban areas, examples of small-scale wind power projects include buildings in New York City that have placed Gorlov-type helical wind turbines on their rooftops since 2009. While the electricity these turbines produce is small compared to the buildings' total needs, they help improve the buildings' environmentally friendly reputation. Some of these projects have received support from the New York State Energy Research and Development Authority.

Grid-connected wind turbines used in homes can store energy in the power grid, replacing electricity purchased from the utility company with locally generated power when available. In some areas, extra electricity produced by small wind systems can be sent back to the grid and sold to the utility company, giving the system owners a credit to help pay for their energy use.

People who use off-grid wind systems must either accept power that is not always available or use batteries, solar panels, or diesel generators to supplement the wind turbine. Small wind turbines, sometimes paired with solar panels and batteries, can power items like parking meters, traffic signs, street lights, or wireless internet devices without needing a connection to the main power grid.

Airborne wind turbines, such as kites, can be used in areas prone to hurricanes because they can be removed before storms arrive.

Impact on environment and landscape

Wind power has a small effect on the environment compared to electricity made from fossil fuels. Wind turbines produce very few greenhouse gases during their whole life, which helps reduce climate change. Using engineered wood in some wind power projects could make the process take in more carbon than it releases. Unlike fossil fuel power, wind power does not use fuel and does not create local air pollution.

Onshore wind farms can change the look of an area. Because wind turbines need a lot of space and have low power density, wind farms usually cover more land than other power plants. The many turbines, roads, and power lines can spread out over large areas, but the land between them can still be used for farming. Some wind farms are not built in places with protected views or historical sites because they might harm tourism, as reported by the Mountaineering Council of Scotland.

Wind farms can harm wildlife by taking up space and breaking up habitats, but these effects are small worldwide. Some birds and bats have been killed by wind turbine blades, but wind turbines cause far fewer bird deaths than fossil fuel power when considering the effects of climate change. These risks can be reduced with careful monitoring of wildlife.

Many wind turbine blades are made of fiberglass and last about 20 years. Blades are hollow, so some are crushed to save space before being thrown away in landfills. However, because blades are strong, they can be used to build long-lasting small bridges for people to walk or bike on. Recycling blades is becoming easier, especially for those made in the 2020s.

Wind turbines make noise. At 300 meters away, the sound is about as loud as a refrigerator. At 1.5 kilometers away, the noise is not heard. Some people who live very close to wind turbines say they feel health effects, but studies by scientists have not found strong evidence to support these claims.

Politics

Wind turbines with fixed bases are a well-established technology, and new ones are usually not given financial support. Floating wind turbines are newer, so some governments provide financial support to help them develop, especially for use in deeper waters.

Financial support for fossil fuels by some governments is slowing the development of renewable energy sources.

Getting permission to build wind farms can take many years. Some governments are working to speed up this process because the wind industry believes it will help reduce climate change and improve energy security. However, some groups, like fishers, may resist this. Governments say that rules to protect wildlife will still be followed.

Studies of public opinions in Europe and other countries show strong support for wind power. A study by Bakker et al. (2012) found that people who opposed wind turbines being built near them had higher stress levels than those who benefited economically from wind turbines.

Although wind power is widely supported, onshore or near offshore wind farms are sometimes opposed because they can affect the landscape, especially in scenic or historically important areas. They may also create noise and affect tourism.

In some cases, local communities own wind farms. For example, in Germany, many people are involved in small and medium-sized wind farms, showing strong local support.

A 2010 Harris Poll found strong support for wind power in Germany, other European countries, and the United States.

In the United States, public support for wind power decreased from 75% in 2020 to 62% in 2021. The Democratic Party supports wind energy more than the Republican Party. President Biden signed an executive order to start building large-scale wind farms.

In China, a study by Shen et al. (2019) found that city-dwellers may resist wind turbines in urban areas due to an unfounded fear of radiation. The study also found that people in urban areas care about costs and the impact on wildlife. Sharing information about wind turbines with the public may help reduce resistance.

Many wind power companies work with local communities to address environmental and other concerns. In some cases, local communities own wind farm projects. Proper government consultation, planning, and approval processes help reduce environmental risks. Some people may still oppose wind farms, but many believe their concerns should be considered alongside the need to address air pollution, climate change, and public opinion.

In the United States, wind power projects often increase local tax revenue, helping fund schools, roads, and hospitals. They also support rural economies by providing steady income to farmers and landowners.

In the United Kingdom, organizations like the National Trust and the Campaign to Protect Rural England have raised concerns about the impact of poorly located wind turbines and wind farms on the rural landscape.

Some wind farms have become tourist attractions. For example, the Whitelee Wind Farm Visitor Centre has an exhibition room, a learning hub, a café with a viewing deck, and a shop. It is operated by the Glasgow Science Centre.

In Denmark, a loss-of-value scheme allows people to claim compensation if their property value decreases due to being near a wind turbine. The loss must be at least 1% of the property’s value.

Although wind power is generally supported, local opposition can delay or stop projects. Concerns include the impact on the landscape, excessive noise, and possible effects on property values. A study of 50,000 home sales near wind turbines found no evidence that prices were affected.

Aesthetic concerns about wind farms are subjective. Some people find them pleasant or symbolic of energy independence and local prosperity. However, protest groups sometimes form to oppose wind power projects for various reasons.

Some opposition to wind farms is dismissed as NIMBYism, but a 2009 study found little evidence that opposition is only due to a "Not in My Backyard" attitude.

Wind cannot be turned off, unlike oil and gas, so it can help improve energy security.

Turbine design

Wind turbines are machines that change the energy from moving air into electricity. After more than 1,000 years of improving windmills and modern engineering, today’s wind turbines come in many types, including horizontal and vertical designs. The smallest turbines are used for tasks like charging batteries for backup power. Slightly larger turbines can help provide some electricity for homes and send extra power back to the electrical grid. Large groups of turbines, called wind farms, are now an important source of clean energy. Many countries use wind farms to reduce their use of fuels like coal and oil.

Designing a wind turbine means deciding its shape and details to capture wind energy. A wind turbine setup includes systems to collect wind energy, turn the turbine toward the wind, change movement into electricity, and systems to start, stop, and control the turbine.

In 1919, a German scientist named Albert Betz proved that an ideal wind energy machine could capture no more than about 59% of the wind’s energy. Modern turbines can reach 70 to 80% of this limit.

The way air moves around wind turbine blades is not simple. Air near the blades behaves differently than air far from the turbine. The process of taking energy from the air causes the air to change direction, which affects objects or other turbines nearby. This is called the "wake effect." Also, the way air moves near the turbine’s rotor is unique compared to other aerodynamic situations. The shape and size of the blades are chosen based on how well they can capture energy and how strong they need to be to handle wind forces.

Besides the blade design, building a complete wind power system also requires planning for parts like the rotor hub, nacelle, tower, generator, controls, and the base that holds everything together.

History

Wind power has been used since humans first used sails to catch the wind. Wind-powered machines, such as windmills and wind pumps, were created in what is now Iran, Afghanistan, and Pakistan by the 9th century. These machines helped grind grain and pump water. Wind power was widely available and did not require rivers or fuel sources. In the Netherlands, wind-powered pumps drained low-lying areas. In dry regions like the American Midwest and the Australian outback, wind pumps provided water for animals and machines.

The first wind turbine designed to produce electricity was built in Scotland in July 1887 by Professor James Blyth of Anderson's College in Glasgow. His wind turbine, which was 10 meters (33 feet) tall and had cloth sails, was placed in his summer home garden in Kincardineshire. It charged batteries created by Camille Alphonse Faure of France, which powered lights in the home, making it the first house in the world to use wind power for electricity. Blyth offered extra electricity to the town of Marykirk to light the main street, but the people refused because they believed electricity was "the work of the devil." Later, Blyth built a wind turbine to supply power to a local hospital, but the technology was not seen as cost-effective at the time.

In Cleveland, Ohio, Charles F. Brush designed and built a larger wind turbine in 1887–1888. His machine had a 17-meter (56-foot) rotor and stood on an 18-meter (59-foot) tower. It produced 12 kilowatts of power and was used to charge batteries or power lights, lamps, and motors in Brush's laboratory. As electricity became more common, wind power was used to light buildings far from main power sources. During the 20th century, smaller wind stations were developed for farms and homes. From 1932, many homes in Australia used wind-powered generators to charge batteries for lights and fans, even with low wind speeds.

The 1973 oil crisis led to research in Denmark and the United States, resulting in larger wind generators that could connect to power grids. By 2008, the United States had 25.4 gigawatts of wind power installed. By 2012, this had grown to 60 gigawatts. Today, wind generators range in size from small units that charge batteries at remote homes to large offshore wind farms that supply power to national networks. The European Union is working to expand wind power use.

In 2023, the global wind power industry added 116.6 gigawatts (GW) of new power to the grid, which was a 50% increase from 2022. This brought the total worldwide wind power capacity to 1,021 GW by the end of the year, a 13% increase from the previous year.