Running notes from TEDGlobal 2009, Session 9.
Eric Giler is working on bringing wireless transmission of electric power to a commercial scale.
Early visions of wireless power were first conceived by Nikola Tesla about 100 years ago. He, in fact, didn’t know why anyone would want to transfer power using wires. But we love electricity so much that we’ve dragged hundreds of millions of miles of copper wiring all over the earth. It’s a huge drain on resources to create the infrastructure. In fact, in contemporary parlance, Eric Giler says “wires suck.” (So do batteries, he says.)
Enter wireless electricity: MIT physicists recently invented technology that can light a 60-watt light bulb at several meters. The concept of “resonant energy transfer” — where the same principles used in electrical transformers are used to send electricity over a long distance — was created when a professor was awoken three nights in the row by a cell phone whose battery was dying. He wondered “Why can’t all this electricity in the walls just come out and power my phone?”
“WiTricity” works using the principle of inductance, where an electric charge is stored in the form of a magnetic field in a coil of a conductor. Two such coils, resonating at the same frequency, can exchange charge across space. This is not radiative power transfer — since it uses only magnetic fields. The technology also limits power transfer to other objects. It’s completely safe and, Giler assures us, won’t to the sort of thing we heard about Rebecca Saxe’s talk (where a magnetic burst interferes with the brain’s processing).
Giler sees unlimited applications for WiTricity — powering electric cars (who, he asks, really wants to have to plug in a car?), appliances of all sorts, industrial manufacturing equipment … even an electrically heated dog bowl. (A business person recently approached Giler to ask him if wireless electricity could do such a thing.)
Giler then does a live, on-stage demo of his system. With a a rectangular conducting frame less than a meter wide mounted on a person-sized stand, and a base transmission unit plugged into a normal power strip, he powers on a regular, commercially available TV screen.
People often ask Giler, “But how small can you make this system?” Taking the example of a cell phone battery running out of charge, he takes a G1 phone and holds it near the transmitting coil — and the phone turns on automatically. He then does the same with an iPhone — and, sure enough, the green “battery charging” symbol appears on the screen.
Photo: Eric Giler at TEDGlobal 2009, Session 9: “Revealing energy,” July 23, 2009, in Oxford, UK. Credit: TED / James Duncan Davidson