New wireless power system demonstrated

By Andrew Laughlin, Technology Reporter

A new system that is able to transfer power without the need for wires has been demonstrated at a high tech conference in Oxford, reports BBC News.

During the TED Global Conference, US firm Witricity showed off its wireless power system that can be used to charge a variety of devices.
While demonstrating its use with a television and mobile phone, the firm's chief executive Eric Giler said that the system could eliminate the need for costly power cables and batteries.

"There is something like 40 billion disposable batteries built every year for power that, generally speaking, is used within a few inches or feet of where there is very inexpensive power," he explained.
Giler said that trillions of dollars have already been invested "to get power from where it is created to where it is used" just because "we love this stuff so much".

He explained that Witricity has been able to install the technology into a GI mobile phone and also demonstrated the system in action.
Alongside this, he also showed how it can be commercially applied to a television set, which would eliminate the mess of wires surrounding most modern TVs.

"Imagine you get one of these [flat-screen TV] things and you want to hang it on the wall," he explained. "Think about it, you don't want those ugly cords hanging down."

The technology is based on research by Massachusetts Institute of Technology's Marin Soljacic, which found that a certain resonance can improve the efficiency of energy transfers.
Witricity's system utilises the resonance of low frequency electromagnetic waves, with a coil connected to the mains supply and another attached to the device.
When the power is switched on, the mains coil creates a magnetic field that is resonant with the other coil so that energy can flow between them and build up a charge to power the device.

"You'd never have to worry about plugging these things in again," said Giler.
He also stressed that the system is safe because the energy transfer is being handled by magnetic fields rather than by creating potentially harmful electric fields.