Wind is powerful, if hard to catch. According to the Atlantic Oceanography and Meteorology Laboratory, a single hurricane releases about 1.5 trillion watts of energy: the equivalent of half of humanity's total electrical generating capacity. The first successful attempt to harness bits of this potential, the "horizontal" windmill, appeared along the modern Iranian-Afghan border somewhere around 800 A.D. These devices, meant to grind flour and pump water, were stone towers surrounding a vertical axle, with a set of twelve sails at the top revolving parallel to the ground about 5 meters below.
Their modern descendants, renamed "wind turbines," are electricity generators. A typical example, the German-made Enercon-53, is a white steel tower 73 meters tall -- about half the height of the Washington monument, a quarter of the Eiffel Tower, almost precisely equal to the Qutb Minar in New Delhi -- supporting three 8.5-meter blades. Such a turbine quietly generates about 2.7 million kilowatt-hours a year. (An average U.S. household uses around 10,655 kWh of electricity each year; thus one turbine can generate enough electricity for 225 to 300 households.) In total, though wind energy remains a relatively modest source of electric power it is growing at remarkable speed. Total world wind capacity passed the 100-gigawatt plateau early this year -- up from 75 gigawatts in 2006, and supplies about 1 percent of world electrical consumption.
Germany is the world's top wind-power producer. The 19,000 wind turbines spread across the flat and breezy terrain of the northern Lander, represent a total capacity of over 22.2 megawatts and produce about 7 percent of German electricity. Running short of suitable land sites for wind farms, German firms are adding 30 offshore farms in the North Sea and Baltic Sea. The German government hopes wind energy will provide 25 percent of electricity consumption by 2020, which is not an unreasonable aspiration: Schleswig-Holstein already gets over a third of its electricity from wind turbines, and across the border to the north, Denmark's national 18.5 percent wind-power share is the largest in the world. The United States, despite its reputation for hydrocarbon addiction, accounted for a quarter of last year's 20-gigawatt capacity growth, and will likely pass Germany as top wind-electricity generator in 2009 or 2010. Among lower-income countries, both India and China are adding wind power very fast.
The appropriately named Chris Landsea, at NOAA's Atlantic Meteorology Laboratory, explains the power of a hurricane:
http://www.aoml.noaa.gov/hrd/tcfaq/D7.html
The New York Times looks at a 36-turbine wind-farm in Ainsworth, Nebraska. Built in 2005 by London-based Renewable Energy Systems, it provides 60 megawatts a year, 1 percent of Nebraska's energy and enough to power 19,000 homes. Text with pictures and video:
http://www.nytimes.com/2008/08/04/us/04land.html
The Global Wind Energy Council's 3rd annual report on the global wind industry:
http://www.gwec.net/uploads/media/
Global_Wind_2007_Report_final.pdf
World Wind Energy Association provides the latest statistics on wind energy capacity:
http://www.wwindea.org/home/index.php?option=com_content
&task=blogcategory&id=21&Itemid=43
A map of potential wind-mining sites around North America:
http://www.stanford.edu/group/efmh/winds/
global_winds.html
Room to grow -- The Energy Information Administration graphs U.S. energy consumption. Total renewable energy accounts for 7 percent of U.S. energy consumption, mainly through hydro and biomass. Wind energy makes up about 1 percent of U.S. electricity consumption and 0.4 percent of total energy consumption:
http://www.eia.doe.gov/cneaf/alternate/page/
renew_energy_consump/figure1.html
But their Energy Department research-side colleagues suggest raising wind energy from 1 percent to 20 percent of electricity use by 2030:
http://www.20percentwind.org/20p.aspx?page=Report
Elsewhere:
India ranks fourth in the world in installed wind-power capacity, with the first wind farms dating to 1986. Overseen by the Ministry for New and Renewable Energy Sources, India's wind power industry now has a capacity of over 8 gigawatts, or about a twelfth of the world total. Wind power constitutes two-thirds of India's renewable energy, the market for which is worth about $500 million and growing at 15 percent yearly. The Ministry estimates that India's achievable wind energy potential, based on current technology and cost, is between 14 and 45 gigawatts. Turbine manufacturer Suzlon accounted for 7.7 percent of world wind power in 2006. The Ministry of New and Renewable Energy Sources:
http://mnes.nic.in/
Then & now -- About 5 of India's 8 gigawatts of wind power are generated in Tamil Nadu. Prince Ilango's 1800-year-old Tamil-language epic Silapathikaram, "The Ankle Bracelet," refers repeatedly to winds. ("Do you not feel the southern breeze bringing us the fragrance of akil and sandalwood, laden with the odors of saffron, chives and musk? It is thick with the smoke of sacrifice, it blows through the palace of the great Pandya king.") Today's Chennai-based Center for Wind Energy Technology is at:
http://www.cwet.tn.nic.in/
A look at the German wind-energy industry:
http://www.wind-energie.de/en/topics/
And last -- a map of global electricity use from the University of Delaware, based on composite satellite photos of the world by night. (See in particular pitch-dark North Korea vs. brightly illuminated South Korea):
http://www.ocean.udel.edu/WindPower/ResourceMap/index-world.html
