This press release is copyrighted by The Institute of Electrical and Electronics Engineers, Inc. (IEEE). Its use is granted only to journalists and news media. Embargo date: 26 March 2002, 5:00 p.m. ET.
The trouble with electricity is that it is very difficult to store: it takes a 400-pound automotive battery to store the energy contained in one pound of gasoline. Unlike coal and oil, which are easily stockpiled, electricity therefore has to be generated where and when it is needed. But that situation is changing as flywheel batteries capable of storing much more energy in much less space get ready for prime time. Unlike old-fashioned flywheels--heavy metal wheels rotating at fairly low speeds--these modern devices are lightweight and rotate at extremely high speeds, in the vicinity of 50 000 rpm.
To withstand such high speeds, they are made of advanced composite materials and are supported by magnetic bearings in which there is no actual metal-to-metal contact. Instead, the rotating masses are held in place by carefully controlled magnetic fields. According to Robert Hebner and Joseph Beno of the University of Texas at Austin and coauthor Alan Walls of Science Applications International Corp. (SAIC), writing in the April 2002 issue of IEEE Spectrum, at this point in their development, flywheel batteries are starting to be deployed in several areas, including power quality improvement, transportation, and military and aerospace applications.
Flywheel batteries can help improve power quality by storing energy near the load (where it is needed), ready to take up the slack anytime the main power feed is temporarily interrupted--by lightning hitting a transformer, for example. Such a battery can carry the load for the time needed to get an emergency generator going. The result: uninterrupted power and relief from the maddening frustration of computer crashes caused by brief power outages.
Flywheel batteries are also a good match to several hybrid vehicle schemes, including high-speed trains and buses. At present, however, they are not practical for passenger cars because such cars would require flywheels smaller than can be constructed economically today. Like ordinary commercial vehicles, military transport is becoming increasingly electrical. Not only are these vehicles adopting electric propulsion (which, among other advantages, allows them to operate in a quiet, "stealth," mode), they are also relying increasingly on electrical and electronic weapons sytems. Some of these systems draw tremendous amounts of electrical power for short periods of time, a job for which flywheel batteries are well suited but which tends to ruin ordinary batteries.
Batteries are also used in orbiting spacecraft to store energy while the craft is in the sunlight for later use when it is in shadow. Flywheel batteries can store energy more efficiently than ordinary batteries, and they have an additional, unique, advantage: their spinning rotors can be used as gyroscopes to help stabilize the craft in its flight.
Contact: Michael J. Riezenman, 212 419 7558, [email protected].For a faxed copy of the complete article ("Flywheel Batteries Come Around Again" by Robert Hebner and Joseph Beno of the University of Texas at Austin and Alan Walls of Science Applications International Corp., IEEE Spectrum, April 2002, pp. 46-51) or to arrange an interview, contact: Nancy T. Hantman, 212 419 7561, [email protected].
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