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WPI Professor Takes the Mystery Out of False Energy Savers

Contact: WPI Media Relations, 508-831-5616

WORCESTER, Mass. -- He's no magician, but WPI electrical and computer engineering Professor Alexander E. Emanuel knows when someone is using smoke and mirrors to create the illusion that a product saves more electricity than it really does. In the mid-1980s he pulled the plug on a purportedly lifetime light bulb by revealing that it had the potential to cause the use of more electricity, corrode equipment, reduce the useful life of transformers, and create problems that could damage motors and power distribution equipment. More recently, he showed that claims for a new generation of energy-saving devices (ESDs) that were supposed to be capable of cutting energy use by as much as 20 percent were equally illusionary.

Plainspoken and unflinchingly honest, Emanuel understands how unscrupulous individuals misuse instruments to make false energy-saving claims and dupe unsuspecting consumers. His ability to separate ESD fact from fancy was rewarded last spring when he received the 1998 Industrial and Commercial Power Systems Department's Ralph H. Lee Prize Paper Award from the Institute of Electrical and Electronic Engineers (IEEE) for his paper "True and False Energy-Saving Devices."

Emanuel is often asked to evaluate new products for their ability to save energy.

"Electrical energy is a product," he says. "We don't see it, but we can measure it and we pay for it-and it is quite expensive. There are thousands of honest engineers designing, improving and searching for ways to make equipment that is more efficient and consumes less electrical energy. The problem is that where there is a market, there are also those who try to take advantage of uneducated consumers by selling 'snake oil'-that is making an easy buck with products whose energy-saving capabilities are questionable or cannot be substantiated."

While Emanuel's paper lists many effective, legal ways to reduce energy consumption, including renewable energy sources, it also unravels the secrets of the "wizards" who seemed to be able to demonstrate energy savings that did not exist. "Until now," he says, "no one knew how they were able to prove their claims. I decided that I must find out and share my findings with the engineering community." From the beginning Emanuel suspected that the current transformer used to measure the current, was the key item where the secret was hidden. After carefully observing the waveforms and the values of the electrical quantities that govern the circuit, it was clear to him that the false savings were caused by inadequate current transformers. Current transformers are devices that supply the meter that measures power or energy with an electric signal proportional with the current that flows through the power line. "When the false ESD is not connected, the instruments indicate more power than the customer actually uses," he explains. "When the ESD is connected, the actual power does not change but the line current decreases and the current transformer error is greatly reduced; hence the power is read correctly. In this way, an unaware observer thinks that the ESD does help save electrical energy."

Emanuel is reluctant to accept credit for his eye-opening report. "Many engineers were puzzled by this 'gizmo' for years, but no one looked into how it worked," he says. "I believe it was the tedious mathematical work that discouraged many from undertaking such a task; nevertheless many electrical engineers knew that the numbers used to substantiate energy savings are false. I was simply the first to write an explanation and publish it. I am glad that my colleagues found this work useful."

A native of Bucharest, Romania, Emanuel earned a B.S., M.Sc. and D.Sc. at the Technion, Israel Institute of Technology and joined the WPI faculty in 1974. He received the Trustees' Award for Outstanding Teaching in 1982 and the Trustees' Award for Outstanding Creative Scholarship in 1984. He is the current Weston Hadden Professor of Electrical Engineering and was the George I. Alden Professor of Engineering from 1987 to 1990. He is a fellow of the IEEE and a member of Eta Kappa Nu and Tau Beta Pi.

An independent technological university founded in 1865, WPI is renowned for its project-based educational program.