Sony inches closer to real products with wireless power

Interest in power transmitted wirelessly has become heavy in recent months, primarily beginning with Intel's breathtaking demo of a light bulb powered wirelessly which it showed off publicly last August.

A light bulb is one thing, but power-hungry consumer electronics are something else. But now Sony has raised the stakes by demonstrating a television that can be powered without a conventional plug.

The 22-inch prototype TV uses "conventional 100 volt electricity" and can receive the power signal over only a short distance: Just 50 centimeters away from the power source, about a foot and a half.

The system basically works in an identical fashion to the way Intel's 2008 light-bulb demonstration works. Power is run through a coil of wires connected to an electrical source to generate a magnetic field. When an identically-shaped coil inside the TV comes within range of the field, an electrical current is induced and the electrical transfer begins.

Sony's system is said to be 80 percent efficient (meaning that 20 percent of the power sent to the initial coil is lost during the transfer to the TV), and another 25 percent or so is lost in the circuitry within the TV. The resulting 60 watts of power are enough to keep a small TV running, but larger applications would require bigger coils and would likely lose more electricity to waste.

Sony hasn't offered any guidance on when this technology might actually be commercialized -- I suspect we're years away from even modest real-world applications -- but the move from ugly lab demos to products with legitimate commercial potential seems exceptionally promising.