On Mar. 7 at the Applied Power Electronics Conference (APEC) in Austin, Texas, the U.S. Environmental Protection Agency (EPA) and the California Energy Commission announced the winners of Efficiency Challenge 2004, an international design competition for power supply efficiency. The winners included Thayer School of Engineering Ph.D. candidates Jennifer D. Pollock (project leader), Xi Nan, and Satish Prabhakaran, and M.S. candidate Magdalena Dale. Associate Professor of Engineering Charles Sullivan served as faculty advisor for the team.
The winning Thayer team, front row from left: Magdalena Dale, Xi Nan, and Jennifer Pollock. Back row, from left: Charles Sullivan, Satish Prabhakaran (photo by Katie Tippit)
The Dartmouth entry, called "Big Green," was a litz wire high-frequency transformer designed to power an office phone and computer. The entry won "Best in Class" in the Open Category which showcases the most efficient power supply designs from industry and academia without cost or packaging constraints. "Power supplies of a similar type generally hover at 60 percent efficiency, and the Dartmouth team showed that 88 percent efficiency is possible," said Chris Calwell, Efficiency Challenge judge. "We congratulate them for their outstanding design."
Open Category entries were received from companies and universities in the United States, Taiwan, and Hong Kong. Said Professor Sullivan, "The overall winner in the 'open category' was Hong Kong Polytechnic University. Although Hong Kong had lower efficiency than we did, they chose to attempt a more difficult class, in which they could get more points for lower efficiency...Dartmouth's entry was outstanding, even when compared only to the other winners. Congratulations to Jenna, Xi, Satish, and Magdalena."
More than 3.1 billion power supplies are currently in use in the United States. Power supplies are devices that convert incoming AC (alternating current) power from wall outlets into low voltage DC (direct current) power needed for numerous consumer and office electronic products. In most power supplies, the magnetic components-transformers and inductors-are responsible for the most energy loss and are the largest, most expensive and most difficult to design. EPA has identified AC-DC power supplies as a major opportunity for reducing global energy consumption and estimates that efficient external power supplies alone could save the United States 5 billion kWh per year, equivalent to preventing the emissions of 700,000 cars.
"The vision for Efficiency Challenge was to achieve dramatic improvements in the energy efficiency of the most widely purchased types of power supplies," said Art Rosenfeld, California Energy Commissioner and presiding member of its research and development committee.
Visit the Efficient Power Supplies website for more information.
By CATHARINE LAMM
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Last Updated: 12/17/08