Energy In The Ether?

By Bob Seay

Nov. 9, 2011

WiTricity car charger

With developing technology, you may be able to charge your electric car without wires or batteries. (WiTricity Corp.)

BOSTON — The widespread power outages that plagued the region after that bizarre late October storm have made people wonder if a day will come when we don’t rely on troublesome wires to bring electricity into our homes and businesses. Is there such a thing as wireless power transmission?
The answer is: Perhaps.
“It exists here in Boston,” said David Schatz, the director of business development and marketing for the company WiTricity, showing off prototypes that can charge an iPhone, run a television set or juice up an electric car — all without wires.
WiTricity is turning the theoretical work of MIT scientist Marin Soljacic into real wireless power products. Soljacic was named a MacArthur Fellow and awarded a MacArthur “Genius Grant” in 2008.
The dream of wireless power goes all the way back to the early days of electricity, when Nikola Tesla tried to build a tower “with a utopian dream of delivering energy freely to all over the world,” Schatz said. (Read about the Wardenclyffe "tower of power.")
The WiTricity model doesn’t work quite the way you might think — that is, it doesn’t send electricity invisibly through the air. “We’ve learned over time that electricity moving through the air is something that maybe you should be wary of. We call it lightning,” Schatz said. Instead, “We use magnetism to transfer energy through the air because magnetic fields are very safe for people and animals.” WiTricity devices contain “resonators” that turn the magnetism into usable electricity.

Eric Giler of WiTricity talks about the promise of wireless electricity. How the science works (pdf).

So far, the WiTricity model doesn’t entirely eliminate wires in your life. Houses would still require some wiring inside to distribute power to different rooms. “We call it room-scale wireless energy transfer. So we can move energy around inside of a room, perhaps around your desk area or around your home entertainment area, so you can get rid of that unsightly and horrible mess of wires,” Schatz said.

To get the electricity inside to begin with, “Your home would probably still be connected to the power plant with wire that came down the street… or your home might be getting energy from solar panels,” Schatz said.

Industry has expressed interest in using the technology to run robotic factory devices and create emergency generators that could be placed safely outside of a house. The military thinks it could possibly reduce the estimated 30 pounds of batteries soldiers carry in the field. One customer is building a WiTricity-powered heart pump.
We may have to put up with those falling wires for a while longer. But given enough time, scientists and engineers might make Tesla’s tower of power a reality… and power outages due to wind and snow a thing of the past.

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