Wind Power Technologies

Summary

By the twenty-first century, wind power was one of the world's fastest-growing sources of new electrical energy. Advances in wind turbine technology adapted from the aerospace industry reduced the cost of wind power from thirty-eight cents per kilowatt hour (during the early 1980s) to as little as one to two cents per kilowatt hour in the 2020s. This rate is competitive with the costs of power generation from fossil fuels, but costs vary according to site.

Definition and Basic Principles

Wind power uses kinetic energy in the form of moving air to turn rotors (and attached blades) that, in turn, power a generator to produce electricity for local use or to be fed into a grid. Wind farms comprise groups of wind turbines. By the early twenty-first century, wind power was becoming competitive in cost with electricity generated by fossil fuels. After 2004, generating electricity from wind became less expensive than fossil fuels in many areas, as its use exploded by 20 to 25 percent annually. As the infrastructure and use of wind power have grown, the unit price has fallen.

Background and History

The use of wind turbines to generate energy is not a new technology. The Spanish author Miguel de Cervantes had his character Don Quixote “tilting at windmills” in the early seventeenth century. The Dutch used their famous windmills to generate modest amounts of energy (as well as to run pumps to empty flooded lowland areas) for hundreds of years; some immigrants to the western United States (US) erected windmills on their farmsteads to generate power before electricity reached them.

What has changed is the size of turbines, their number, efficiency, and organized use to compete with fossil fuels as an energy source in a world experiencing climate change. The use of wind as an energy source in an organized manner associated with electrical grids began with the oil crisis of the 1970s, in which the entire world saw prices of fossil fuels, the primary power source, increase rapidly as a result of disruptions in supply. By the 1980s, wind arose as a serious alternative to fossil fuels in power planning, as concentrations of greenhouse gases in the atmosphere increased and were recognized as a source of climate change.

Denmark, dependent on imported oil during the 1970s, made an enduring commitment to achieve energy independence when supplies were embargoed, and its economy was, as a result, devastated. Wind power became an important part of this strategy, and Denmark became a world leader in wind turbine technology. Work on Danish turbines is a major reason the technology has come to generate electricity that competes in price with oil, coal, and nuclear power. In the meantime, Denmark built infrastructure that provided nearly 15,000 jobs by the early 2020s. In matters of advanced technology, Denmark dominates the worldwide wind-power industry. By 2024, 46.8 percent of Denmark's power came from wind energy, and the country set a goal to stop using fossil fuels for electricity within ten years. The country committed to being completely reliant on renewable energy sources by 2050. In 2021, Denmark announced the construction of the world's first "energy island," intended as a hub for two hundred giant wind turbines.

In 2008, Europe's largest onshore wind farm to date, able to generate enough power for 200,000 homes, was approved by the Scottish government. Announcing the approval of the new wind farm before the World Renewable Energy Congress in Glasgow, First Minister Alex Salmond said the 152-turbine Clyde Wind Farm near Abington in South Lanarkshire would make Scotland the green energy capital of Europe. By 2013, according to European Wind Energy Association figures, Clyde Wind Farm had been eclipsed in size by the Romanian wind farm Fantanele and Cogealac, with its 240 turbines and 600-megawatt capacity. In 2024, Europe's largest wind farm was the Swedish Markbygden Wind Farm, which provided 2 gigawatts of wind power capacity.

In 2002, Spain's tiny industrial state of Navarre generated 25 percent of its electricity through wind power. By 2019, 70 percent of its electricity was from wind and sun. The World Population Review listed these countries as the top five by the end of 2021 in terms of total wind-generation capacity: China, with an estimated 328,970 megawatts; the US, 132,738 megawatts; Germany, 63,760 megawatts; India, 40,070 megawatts; and Spain, 27,497 megawatts.

The US Environmental Protection Agency estimates that electricity generation accounted for about 20 percent of US greenhouse gases as of 2021. In 2021, wind turbines in the US generated about 122,478 megawatt hours of electricity, according to the US Energy Information Administration. Wind has become a major energy source in some areas. Following nine years of review and copious controversy, on April 28, 2010, the US federal government approved the US's first offshore wind farm, Cape Wind in Nantucket Sound, a 130-turbine array off Nantucket, Massachusetts. However, local opposition to the project forced its termination. The country's first offshore wind farm instead became Block Island Wind Farm, a five-turbine installation in Long Island Sound off the Rhode Island coast, which was deployed in May 2017. In 2024, the largest wind farm in the US was the Alta Wind Energy Center in California.

Some US state laws require utilities to work toward generating 15 to 25 percent of their electricity from sources that do not produce carbon dioxide. Wind capacity in the Pacific Northwest, where it is often used with hydroelectric, soared from only 25 megawatts in Oregon in 1999 to 3,085 megawatts in Washington and 3,415 megawatts in Oregon by 2019, according to the US Department of Energy (DOE). The Plains states have also widely adopted wind power. In late 2020, the DOE reported Oklahoma had over 9,300 megawatts of wind power capacity, trailing only Texas and Iowa.

According to Randall Swisher, former executive director of the American Wind Energy Association, the electrical grid in the Northwest is especially inviting to wind-power developers because of its hydroelectric distribution network, relatively reliable wind, progressive utility companies, and state laws that establish preferences for renewable energy. Hydroelectric dams also have been built in river gorges and other valleys that are natural conduits for wind. The transmission lines connecting the dams with urban areas have been created with considerable surplus capacity, a built-in network for wind power. Farmers in this and other areas have earned $3,000 to $8,000 per year per turbine on their property.

How It Works

Wind power uses kinetic energy, forcing moving air to turn a rotor attached to a set of blades that powers a generator to produce electric power for local use or to be fed into a grid. Wind farms comprise groups of wind turbines. The power capacity of wind turbines may be restricted only by the size of a blade that can be hauled to a site, mounted, and maintained with some degree of structural integrity. A turbine at 250 feet takes advantage of winds that are 20 percent stronger at that elevation than at 150 feet.

Wind power, in its infancy, also has been plagued by a shortage of transmission capacity that will allow its transport from turbine sites to users, many of whom live in urban areas. Texas has been a leader in the US in building transmission capacity. In 2007, the Public Utility Commission of Texas approved transmission lines across the state to carry up to 25,000 megawatts of wind energy by 2012, a 500 percent increase from 2008. Shell and TXU Energy were planning a 3,000-megawatt wind farm in the Texas Panhandle. By late 2020, Texas had installed wind power of 32,686 megawatts and was producing about 20 percent of the state's electricity, according to the US Department of Energy. Land values in some counties with wind farms have nearly doubled. By 2024, 28.6 percent of Texas' energy came from wind power.

A major problem for wind energy is that the hottest days, when power demand is highest, are usually the least windy. Wind power cannot be used without energy-storage technology or other renewables to replace fossil fuels all the time.

Applications and Products

Wind power has developed as a large-scale industry and supplementary source of electricity to which the science and engineering of rotors and supporting assembly (including airline technology) has been applied. To date, the promise of wind energy pertains mainly to large-scale farms that can contribute energy to the electric grid and limit emissions of greenhouse gases from energy produced by fossil fuels.

Wind energy, on a smaller scale, useful to individual homeowners or small businesses, also has come into use. The US invented household-scale wind turbines in about 1920 and has been a world leader in that technology. Many of the world's household wind turbines were installed in the US. Growth in the number of household wind turbines averaged 14 to 25 percent a year between 2000 and 2009 worldwide, according to Randall Swisher. In the 2020s, household wind turbines were included in the over 70,000 turbines in the US. At least one-half acre of land is required for a residential wind turbine, and regulators must permit a tower of at least 35 feet (the higher the tower, the more efficient the turbine). Technological problems (such as vibration that may damage brick chimneys) have limited small-scale applications to date. Still, when these problems are solved, small turbines could come into use (possibly supplemented by other sources, such as solar power) to allow small users to achieve independence from fossil fuels.

Careers and Course Work

Careers in wind power range from technicians to electrical engineers, electrical design engineers, environmental architects, and turbine installers. Repair technicians and wind farm managers will also be in demand as wind power becomes more widespread. Large companies, such as General Electric, employ some developmental engineers. Education varies from a few months for installers to college degrees (undergraduate and graduate) for engineers. There are wind-energy educational programs, public and private, at two- and four-year colleges in many states around the country.

Wind-power education usually includes advanced mathematics, physics, computer science, electrical engineering, and mechanical engineering courses.

The educational landscape for wind power is comparatively new and evolving rapidly. In 2008, Professor Ernest Smith began to teach the first-ever wind law course at the University of Texas School of Law. Texas Tech University Wind Science and Engineering Research Center helped form the National Wind Institute in 2012. California Wind Tech in Rancho Cucamonga launched intensive entry-level training for wind technicians and other professionals in courses that could lead to jobs in circuit troubleshooting, wind turbine construction, and schematic reading in as little as one month. Iowa State University has established a graduate-level wind-energy science, engineering, and policy course focusing on wind-power generation.

Social Context and Future Prospects

Wind turbines have not been universally welcomed. Some members of the population and neighbors complain they comprise “visual pollution.” The power capacity of wind turbines may be restricted only by the size of a blade that can be hauled to a site, mounted, and maintained with some degree of structural integrity. A turbine at 250 feet takes advantage of winds that are 20 percent stronger than those at 150 feet, said Dr. Mark Z. Jacobson, an associate professor at Stanford University's Department of Civil and Environmental Engineering.

The bigger the turbine, the greater the chance it may kill birds; according to the US Fish and Wildlife Services, wind turbines kill over one million birds yearly in the US. However, other research has shown that it is a small fraction of the millions killed each year by nuclear and fossil fuel power plants.

Without major advances in storing large quantities of electricity or significant changes in how regional power grids are organized, wind may run up against its practical limits sooner than expected. In many places, wind blows best when demand is low on winter nights. Robert E. Gramlich, policy director with the American Wind Energy Association, said that wind energy could be integrated into an electrical grid on a large enough area to balance ebbing wind in one part by continuing breezes in another.

Noise and vibrations from large wind turbines, which some people compare with a jet taking off, have reportedly caused headaches and insomnia in some nearby people. Nina Pierpont, a Malone, New York pediatrician, named this "wind turbine syndrome." Others have claimed that wind turbines can cause anxiety, vertigo, depression, stroke, epilepsy, or other neurological impacts. However, studies have not proven links between turbines and harmful health effects. In 2008, the European Union exonerated wind turbines of guilt in any medical condition except occasional sleep loss. Avoiding adverse outcomes on nearby residents is usually simple: establishing proper setbacks, distances of 1,000 to 2,500 feet, with some people insisting on a mile or more setbacks.

Bibliography

Birch, Tamara. “The 7 Largest Wind Farms in the World.” The Ecoexperts, 23 May 2024, www.theecoexperts.co.uk/blog/largest-wind-farms. Accessed 2 June 2024.

Brown, Lester R. Plan B 4.0: Mobilizing to Save Civilization. W. W. Norton, 2009.

“Denmark - Country Commercial Guide.” International Trade Administration, 20 Jan. 2024, www.trade.gov/country-commercial-guides/denmark-renewable-energy-products. Accessed 2 June 2024.

"Denmark to Build 'First Energy Island' in North Sea." BBC News, 4 Feb. 2021, www.bbc.com/news/world-europe-55931873. Accessed 11 Jan. 2022.

Burton, Tony, et al. Wind Energy Handbook. John Wiley & Sons, 2001.

Flannery, Tim. The Weather Makers: How Man Is Changing the Climate and What It Means for Life on Earth. Atlantic Monthly Press, 2005.

Gipe, Paul. Wind Power: Renewable Energy for Home, Farm, and Business. Chelsea Green, 2004.

Loss, Scott R., et al. "Estimates of Bird Collision Mortality at Wind Facilities in the Contiguous United States." Biological Conservation, vol. 168, Dec. 2013, pp. 201–9, doi:10.1016/j.biocon.2013.10.007. Accessed 29 Mar. 2018.

McGuire, Bill. Surviving Armageddon: Strategies for a Threatened Planet. Oxford University Press, 2005.

Musgrove, Peter. Wind Power. Cambridge University Press, 2010.

Office of Energy Efficiency & Renewable Energy. WINDExchange, Wind Energy Technologies Office, US Dept. of Energy, windexchange.energy.gov. Accessed 2 June 2024.

“Wind Power by Country 2024.” World Population Review, worldpopulationreview.com/country-rankings/wind-power-by-country. Accessed 2 June 2024.