Wind power
In 2024, wind supplied about 2,500 terawatt-hours of electricity. This output represented over 8% of the world's total electricity generation. Global installed capacity exceeded 800 gigawatts following the addition of roughly 100 GW during 2021. China and the United States drove most of these new installations. Thirty countries generated more than one-tenth of their electricity from wind that same year. Wind generation has nearly tripled since 2015. Analysts say expansion must accelerate to meet Paris Agreement goals. They recommend growth of over 1% per year in electricity generation.
Wind is air movement within Earth's atmosphere. In one second, a volume of air passes through an area. If air density remains constant, the flow rate equals this volume multiplied by speed. Power transfer scales with the third power of wind speed. Doubling wind speed increases available power eightfold. The global average kinetic energy reached approximately 1.50 megajoules per square meter between 1979 and 2010. Northern Hemisphere values averaged 1.31 MJ/m² while Southern Hemisphere figures hit 1.70 MJ/m². The atmosphere acts as a thermal engine sustaining circulation against friction at 2.46 W/m². Tools like Renewables.ninja provide time-varying simulations at hourly resolution. The Weibull model closely mirrors actual distribution of ten-minute wind speeds at many locations.
German physicist Albert Betz proved in 1919 that no machine could capture more than 59% of wind kinetic energy. Modern turbines reach 70 to 80% of this theoretical limit known as the Betz limit. Most large turbines feature three blades attached to a nacelle atop a tall tubular tower. A horizontal axis design dominates current installations. Individual turbines within farms connect via medium voltage systems often rated at 34.5 kV. Engineers set distances of seven times rotor diameter between each turbine. Variable speed generators combine with partial or full-scale converters for grid interconnection. Black start capabilities are being developed for regions like Iowa where wind generates most electricity.
Onshore wind costs have fallen significantly since 1983. BusinessGreen reported grid parity reached parts of Europe by the mid-2000s and the US around the same time. A 2021 Lazard study estimated new wind-generated electricity cost between $26 and $50 per megawatt-hour. New gas power ranged from $45 to $74/MWh during that period. Offshore wind averaged around $83/MWh. Northern Eurasia, Canada, Patagonia in Argentina, and some US areas offer best onshore conditions. Turbine prices dropped due to competitive energy auctions. Subsidies remain common for offshore projects but less necessary for onshore wind in China. The sector employed an estimated 1.25 million people in 2020. Community ownership models strengthen rural economies through steady income for farmers.
Wind turbines generate some of the lowest life-cycle greenhouse-gas emissions among all energy sources. Thousands of birds and bats die annually from blade collisions though fossil fuel stations cause far more deaths when climate effects are included. Onshore farms require large land areas creating potential habitat fragmentation. Land between turbines remains usable for agriculture. Many blades consist of fiberglass with a twenty-year lifetime. Some manufacturers now design blades for complete recyclability. Noise levels reach approximately 45 decibels at ten meters distance. This is slightly louder than a refrigerator. Peer-reviewed research generally does not support claims of negative health effects from proximity. A report by the Mountaineering Council of Scotland concluded wind farms harmed tourism in scenic Scottish areas.
Transmission networks must cope with hourly daily or seasonal variability in power output. Instantaneous electrical generation and consumption must balance to maintain grid stability. Utility-scale batteries often balance shorter timescale variations while car batteries may gain ground from mid-2020s. When transmission capacity fails to meet generation, farms produce below full potential in curtailment processes. Peak wind speeds sometimes do not coincide with peak demand periods. Interconnecting widely dispersed geographic areas via HVDC super grids offers future options. Pumped-storage hydroelectricity complements wind well by holding back water during strong winds. These systems release stored energy when needed despite being only about 75% efficient. High penetration levels could require increased load shedding or system interconnection.
Wind-powered machines used to grind grain and pump water developed in Iran Afghanistan and Pakistan by the 9th century. The first turbine for electric power production appeared in Scotland in July 1887. Professor James Blyth installed a high cloth-sailed unit at Marykirk in Kincardineshire. It charged accumulators to light his cottage making it the world's first house powered by wind. Locals turned down surplus power offering calling electricity the work of the devil. Charles F. Brush built a larger machine in Cleveland Ohio during winter 1887, 1888. His rotor spanned fifty feet mounted on an eighteen-meter tower rated at 12 kW. The 1973 oil crisis triggered investigations leading to utility-scale generators. By 2008 US capacity reached 25.4 gigawatts while 2012 figures hit 60 GW. Global additions totaled 116.6 GW in 2023 bringing total capacity to 1,021 GW.
Common questions
How much electricity did wind power supply globally in 2024?
Wind supplied about 2,500 terawatt-hours of electricity in 2024. This output represented over 8% of the world's total electricity generation.
What is the maximum theoretical efficiency limit for wind turbines according to Albert Betz?
German physicist Albert Betz proved in 1919 that no machine could capture more than 59% of wind kinetic energy. Modern turbines reach 70 to 80% of this theoretical limit known as the Betz limit.
When was the first turbine for electric power production installed in Scotland?
The first turbine for electric power production appeared in Scotland in July 1887. Professor James Blyth installed a high cloth-sailed unit at Marykirk in Kincardineshire.
Which countries drove most new wind installations following the addition of roughly 100 GW during 2021?
China and the United States drove most of these new installations. Global installed capacity exceeded 800 gigawatts following the addition of roughly 100 GW during 2021.
How much did it cost to generate new wind-generated electricity in 2021 according to Lazard?
A 2021 Lazard study estimated new wind-generated electricity cost between $26 and $50 per megawatt-hour. Offshore wind averaged around $83/MWh while new gas power ranged from $45 to $74/MWh during that period.