Wireless electricity – WiTricity resonant energy transfer

Wireless power has been available for a century, ever since Nikola Tesla worked on its development. The genius’s Wardenclyffe Tower was to be an experiment in beaming electricity wirelessly across the world, eliminating the need for a wired power grid. Since then, wireless electricity has been developed mainly for usage at short distance and for reasonably trivial applications as charging battery-powered equipment. Eric Giler’s from WiTricity made a great ten-minute demonstration of wireless power at this year’s TEDGlobal shows.

Giler from demonstrated how to wirelessly power a TV from a distance of some 2m, and then proceeds to charge Nokia, Apple and T-Mobile cell phones using very compact versions of the same technology. As Giler points out, batteries and wires are wasteful of materials, they have a very finite life-span and they’re energy-inefficient to produce. You could charge your electric car while it is parked inside your garage, re-charge your devices or power your computer or TV without the restraints. You could move your TV or computer anywhere you want in the room, without so many wires you usually have to move.

Invented by Marin Soljacic from MIT, the technique can power an entire room, assuming the room is filled with devices capable to receive the wireless power. Unlike the products from the competition, charging station and charging devices don’t have to be close to each other in order to transfer energy. Instead, they depend on so-called magnetic resonance. Like acoustical resonance, which allows an opera singer to break a glass across the room by vibrating it with the correct frequency of the voice’s sound waves, magnetic resonance can launch an energetic response in something far away.

A powered charger installed into a wall or behind a closet could power the whole room or even a larger charger in your basement could power the rest of the house, wirelessly. “Biological organisms are invisible to, and unaffected by, a magnetic field,” Soljacic says. We all live in our planets magnetic field and some medical treatment is achieved with the usage of magnets. On the other hand we also know image on our monitors and TVs get distorted when they are exposed to a magnetic field. Creation of a large field which would power the whole house and constant long-term influence of those forces should be tested.

Another greater obstacle in wireless power on a larger scale is that there is not a way from electrical production companies to charge for their services. Hence, as soon as those companies stop charging electricity you can expect to receive free wireless electricity everywhere. And we all know that’s not going to happen in near future.