Is Wireless Power Closer Than We Think?
Tesla Would Be Proud
A few years back, Marin Soljačić was driven from bed by the insistent beeping of his mobile phone. But it wasn’t beeping for him to answer it, it was beeping for him to plug it in. Since that night, the assistant professor of physics at MIT, has been thinking about ways to start his phone charging as soon as he enters his home - without the need for plugs or wires.Jennifer Chu at Technology Review writes that Soljačić considered using radio waves, but found that most of their energy would be lost in transmission. Targeted methods like lasers require a clear line-of-sight and could be dangerous for anything in their way. According to Chu, he eventually settled on a phenomenon called magnetic resonance coupling, in which two objects tuned to the same frequency exchange energy strongly but interact only weakly with other objects.
“A classic example is a set of wine glasses, each filled to a different level so that it vibrates at a different sound frequency. If a singer hits a pitch that matches the frequency of one glass, the glass might absorb so much acoustic energy that it will shatter; the other glasses remain unaffected.”
Now, Soljačić and his team have successfully demonstrated the use of magnetic resonance coupling to power a 60 watt light bulb from a distance of roughly two meters - and through a thin wall.
The most effective setup, thus far, transfers power over a distance of two meters with about 50 percent efficiency. The team is looking at other materials to decrease coil size and boost efficiency. “While ideally it would be nice to have efficiencies at 100 percent,” says Soljačić. “So realistically, 70 to 80 percent could be possible for a typical application.”
While some wireless power technologies have emerged in the marketplace, Soljačić’s technique differs in that it might one day enable devices to recharge automatically, whenever they come within range of a wireless transmitter.
I think it’s a new technology and it has a lot of promise I for one think it would be awesome if I could just walk into my house and have my ipod and cell charge. Sure it’s not ready for mainstream yet but neither were computer when they first came out, or cell phones.
@Uncle B> I didn’t see any interest to a technique with a loss of energy of one third or one fourth, so thanks for citing medical applications (medical devices)! Obviously, there are cases where you don’t want wires going through … the skin. Could be better suited than Foucault currents in some applications.
@Tyler “put a power plant next to the sun”> huh? Why not use *directly* the tremendous energy coming from the sun? If you really want a satellite, you’d better put it in geostationary orbit, providing energy at night (it’d be lit 24/24 7/7 and it’d be “there” night’n'day). You could even have energy near the poles during the 6 months night, though it’d be difficult to point at the horizon. And there’d be a huge barrier: the atmosphere. Last problem: the size of the thing. Human needs in energy are currently pretty huge, how could you imagine a satellite providing alone the same energy as dozens of (nuclear, gaz, coal) plants? Focused on a city or an entire hemisphere without warming the atmosphere? Mmh I think solar panels or solar heaters’ll be more convenient for now
How is this clean? Suck up some power from the grid or elsewhere *then* throw away 30% of it?
@Shane–If you’re willing to pay 30% extra on your power bill for this (ie, use 30% more power in the process of going wireless), why do you care about “green” technology?
Fantastic, kepp your rechargeable applicance with you every time you go to visit a fiend
Tesla’s fascination with wireless power was actually his downfall. He had invented radio (Marconi’s “invention” used 17 Tesla patents), and secured funding from JP Morgan to develop a global radio network, but when Morgan found out that Tesla’s main desire was wireless transmission of electric power, funding was withdrawn and Tesla spent the rest of his life a pauper.
Why? If you transmit energy wirelessly, there is no way to bill users. And with the inefficiency inherent in a wireless transmission method, much more power would have to be produced than what was actually used.
Electric toothbrush “wireless” chargers are nothing earth-shattering; it’s a simple transformer using magnetic induction. Move the handle away from the base even a bit, and the charging stops.
Remember, Tesla’s transmitters were MASSIVE and pre-dated the era of radio. He literally burned up a generator in Colorado Springs when tuning up a transmitter that would later light a few hundred-watt bulbs 25 miles away.
For efficient wireless transmission to work, you’d need a medium that is highly directional, harmless to humans/animals in its path, and immune to scattering or attenuation from the atmosphere or objects in its path. In other words, you need a medium that hasn’t been invented yet.
I do not think this is very far fetched and I do believe it will start with smaller gadgets. I do not believe that battery companies will take kindly to the idea oddly unless they have patent on these methods.
How did Tesla wirelessly power the worlds fair? Seems this day and age we should be able to make leaps and bounds to where Tesla left off. Could it be that he was just that brilliant?
Why are massive brains busying themselves with wireless power transmission for cell phones before they have solved the stupidity of every cell phone coming with a charger that is incompatible with every other brand and model of cell phone - and also incompatible with every other device (shaver, toothbrush, camera, etc.) that requires a charger to convert household current. Talk about waste! And don’t even get me started about remote control devices.
“P Bartlett said on May 2nd, 2008 at 6:24 pm
One of the seven signs of bogus technology is that the inventor pitches the technology directly to the media rather than peer reviewed journals.
Thats what we have here. The guy is a charlatan.”
What a buffoon you are Mr. Bartlett. As everyone knows, the intellectual tyranny of the “peer review” system has been systematically used to stifle innovation and preserve the economic monopolies and status quo of the elite, to the detriment of human progress and wellbeing. Check out suppressed discoveries in the fields of free energy, anti-gravity, cancer cures, etc.