Energy in Wind
Part of the Climate Change exhibition.
Part of the Climate Change exhibition.
Wind can push a ship across the ocean or it can power your dishwasher. When specialized windmills, known as wind turbines, spin in the breeze, they turn a shaft connected to an electrical generator that produces electricity. Groups of wind turbines—a wind farm—on land or offshore, where winds are about 90 percent stronger and more consistent, can provide as much electricity as a coal-fired electrical plant.
In theory, experts say, the winds off the mid-Atlantic coast of the United States could provide all the power needed by that densely populated region. In reality, wind power is too variable to depend on entirely: without a means of storing energy, wind farms cannot consistently provide any one place with more than about 20 percent of its electricity demands.
Denmark gets over 20 percent of its electricity from wind power. When Danish wind farms generate excess electricity, power lines carry it away to be used elsewhere. Some of that power is stored by pumping water uphill to high reservoirs. When extra electricity is needed, that water is released from reservoirs to flow through hydroelectric generators. Denmark had to negotiate with its neighbors to make this plan work: most of the reservoirs are in the mountains of nearby Norway.
Critics of wind power say that turbines are bad news for birds. But advocates argue that the danger is no worse than that posed by any tall structure, such as a skyscraper or electrical tower. And turbines can be placed away from known bird habitats to minimize deaths.