Will Energy Storage Play a Big Role in the Electric Grid?
Tuesday, November 22, 2011 - 11:30
in Physics & Chemistry
More than 200 tops spin in vessels half-buried in the dirt outside Stephentown, N.Y., a town near the Massachusetts state line. Inside the vessel a vacuum permits each top to rotate as many as 16,000 times per minute, despite the fact that each weighs more than one metric ton, thanks to its steel and carbon-fiber composition. Such fast spinning in a vacuum (to reduce friction) allows each top to store some 25 kilowatt-hours of electricity. When the grid's frequency gets out of whack--that is, if the 60-times-per-second current should reverse its flow--all the magnetically-levitated tops speed up, slow down or flip direction to ensure the grid stays in tune. [More]