Double the wind speed and a turbine gets eight times the power
The energy carried by moving air rises with the cube of its speed. A breeze twice as fast delivers eight times the power, and increasing speed by a factor of about 2.15 multiplies it tenfold. That steep curve explains why wind farm developers obsess over exactly where they build.
The cube law follows from simple physics: faster wind pushes more air through the blades each second, and each parcel of air also carries more energy. Because of this, a site's average wind speed on its own says little about output. Planners fit statistical curves, typically a Weibull distribution, to hourly or ten-minute records to predict how often strong winds actually blow. Global maps such as the Global Wind Atlas, from the Technical University of Denmark and the World Bank, estimate potential everywhere, and the economically extractable total considerably exceeds all the power humanity currently uses.
Wind itself comes from the atmosphere acting as a heat engine, absorbing warmth where it is hot and shedding it where it is cool. Between 1979 and 2010, wind kinetic energy averaged about 1.50 megajoules per square metre, higher in the Southern Hemisphere than the Northern. High latitudes have the best resource, and in most places winds blow harder at night and in winter, just when solar panels produce least, so the two pair well.
In 2025 wind supplied about 2,700 terawatt-hours, over 8 percent of the world's electricity, and 30 countries got more than a tenth of their power from it in 2024. In many places a new onshore farm now costs less than a new coal or gas plant. Turbines in a farm are spaced about seven rotor diameters apart, linked by a medium-voltage network, and a substation steps the current up for long-distance transmission. The land between them can still be farmed.
Offshore farms catch steadier, stronger winds and bother fewer onlookers, but they cost considerably more to build and maintain; nearer ones connect by alternating current and distant ones by high-voltage direct current. In November 2021 the largest was Hornsea in the United Kingdom, at 1,218 megawatts. Because output varies, grids pair wind with storage or with sources that can be dispatched on demand.
Source: Wind power
