Wireless Electricity

wireless electricity power clean energy efficiency

Wireless electricity is in our near future, so get ready to quit tripping over all your electronic charger wires.  An article on CNN today highlights a new company working on wirelessly powered gadgets and took us on a short glimpse into our future. The CNN article discusses the venture that came out of research performed at MIT (they're the engineering arch-nemesis to my Alma mater, Georgia Tech) called WiTricity.

wireless electricity clean energy Tesla Wardenclyffe Tower

Tesla Wardenclyffe Tower

Wireless power is nothing new.  In fact, Nikola Tesla had several patents regarding wireless electricity transfer as early as 1900.  And looking into the future, Japan has announced serious plans to put solar panels in space and beam the power wirelessly down to earth.  Japan isn't talking about just a few Watts.  They're talking 1 Giga-watt!  That's the equivalent of a coal power plant's output.  Let me assure you that you don't want to walk in the way of that beam unless you want to end up wirelessly transmitted to heaven (or hell if you are behind Magniwork).

The basics behind wireless electricity transfer are really pretty straightforward and Popular Science had a great article on the topic (that also covered the company that came out of MIT) in January of 2008, so the CNN article isn't exactly breaking news.

To simplify, wireless electricity transmission is caused by electric current at a specific frequency  running through  one coil, which causes a magnetic field oscillating at that same frequency to be emitted from the coil.  When that magnetic field comes in contact with an identical coil at another location, the 2nd coil resonates at the same frequency as the magnetic wave and a current is induced in the second coil.  To see a better explanation with pictures, see this how wireless electricity works.  ( side note: I would like to understand better how the resonance induces a bigger current than just a regular magnetic field.  I understand the basics of resonance, but I'm just not sure how the resonance causes a larger current induction in the receiving wire.  Please feel free to explain in the comments)

As we know, wireless electricity is not a new idea, and in fact, I already use it in my house with my electronic toothbrush.  The charger is plugged in, but the toothbrush just rests on the charging stand, getting charged wirelessly.  However, the distance separating the stand from the toothbrush is probably a millimeter, with just some plastic in between.

Another type of wireless electricity transfer exists where a tiny amount of energy is transferred over a long distance.

WiTricity is breaking ground because it is sending a decent amount of power over a large distance.  They are achieving this by what they are calling "magnetically coupled resonance".   Which relies on the magnetic resonance to induce a larger current in the devices the power is being beamed to, or at least that's how I understand it.

So, what does this mean for energy conservation?  Well, in regards to actually saving energy I really dont think wireless charging will be more efficient.  The CNN article says the charging devices are about 70 to 90 percent as efficient as using a wire.  But apparently they do shut off when the device is done charging, so that would lead me to believe there is no vampire load.

The biggest environmental benefit that is mentioned in the article is that wireless charging would eliminate the need for batteries in many appliances that are used in the home.  The CEO, Eric Giler, stated in the article that:

... wireless electricity has many environmental benefits. Companies make about 40 billion disposable batteries each year, he said, and wireless electricity could do away with that.

I'm a little skeptical at how many devices will really be able to be directly powered (that means without batteries) by wireless electricity transmission.  Laptops and cell-phones will still need batteries if you ever need to take them out of the house. For instance, in my office right now, there is only one device that would benefit from wireless charging by getting rid of batteries, and that is my wireless mouse.  But I use rechargeable batteries in it!  I think "getting rid of 40 billion batteries" may be a bit of an exaggeration.   Sure, it may remove a few batteries, but it is less efficient than wired power.  I'd love to see more data on the environmental benefits of wireless electricity transmission!

There are other questions to this technology, like what it does to our health?  I'm sure we'll be hearing a lot more on this one as the technology matures. (Especially if Japan is really going to attempt their death ray space power transmitter.

Nevertheless, wireless power transmission is pretty darned cool.  I will say that it would be great to drive my electric car (not yet purchased) into my garage and have the battery charged without me having to get my hands dirty!

***Update 1/21/10: Popular Science recently had an article on RCA Airnergy.  Basically, it's a battery that is charged by wireless networks.  Pretty cool stuff.

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excellent wireless want full detail about this one electricity great
Thanks for the article and the picture. You know, there are many things at play with this technology, I have read Tesla's journal on it, patent, build a small model and read about it a bit more than some. What Tesla came to offer to the world is this and he built a tower for a it but it got shutdown. Tesla was not trying to get rid of batteries (I am not sure if they even existed), nor did he just tried to get rid of wires. He was trying to give energy for free and super free for the world. Other than the fact that it sounds too great to be true, you have to really look at it from a pure visionary scientist with out any and I kid you not any desire for just fame and money. His motifs and work are pure pure scientific and engineering to a point that his financial backers just shutdown his last project, why? well, what happens if you can't make money out of coal, copper and oil any more? You gonna make antenna and make the same level of cash? I believe the avg human need of materialism and being subjugated to few who have it, basically buried Tesla 's technology. Now I mentioned that Tesla's wireless tech was going to give free and super free energy. I chose the first free because the resonating tower (known as wardenclyff tower) when built worked by the potentials in the ion sphere on earth and resonances around the earth) So pretty much earth, it's atmospheric potential or whatever is responsible for swinging generating wireless power tranmitted I think through earth itself (at high frequency voltage electricity is cool and gentle and moves through insulators instead and somehow forms higher than speed of light standing waves which are called longitudinal or scalar waves within a theorized ultimate medium called aether). Aether transmits energy across every point of the planet instantly and losslessly (99.999%) Another effect Tesla discovered is that not only it was lossless and instant wireless it also came to light that energy was magnified and I, for lack of vocabulary, said this is super free energy. This one is hard for me also to get through but it basically could work like this: if you have a similar coil receiving the waves at certain frequencies it is possible that the coil will resonate with a higher amount of energy. This could be analogous to a child on a swing where timed jerks of the child will cause to swing to reach higher levels of oscillations and hieghts. The total movement of the swing then could be larger than of the child; however, note that this is not a professional opinion it is me trying to see how it works. The phenomena discussed here such as lossless transmission and overunity is heavily studied by Professor Konstantin Meyl from Germany and Eric Dollar. I just ordered Mr. Meyl's book on scalar waves I suggest you do the same. Finally the kit manual I followed to test the ideas (it has all the basic overunity, lossless, etc for testing) is adopted from Meyl by IEEE Steve Jackson and is put here for you to try :)
I think Wireless energy is a neat idea, but I have one huge fear. What will this widespread use of wireless energy do to our bodies? They have already linked cell phone usage with cancer, and that is a fairly small exposure in relation to what Angus mentioned. I don't know, it just sounds like a double edge sword to me. Fascinating, but scary too...
Even though we are bombarded by EMF via sunlight, EM radiation from specific high frequencies can hurt us (microwaves, etc) if not as LOS (line-of-sight) pointed at us. A resonant frequency that increases it's amplitude may be bad if penetrating the human body. There is no easy solution to free energy.
And according to WiPower, inductive charging systems work with about 80% to 90% efficiency -- roughly the same as plugging directly into a wall socket. That blows away the industry average for wired chargers, around 40%. regards.
That's pretty crazy. I didn't think wireless electricity was even a possibility. Leave it to someone like Tesla though :) That guy sure did love his electricity.
Great Blog, I cant wait like you to drive my electric car into the garage and have it charged up without having to touch a thing.
Imagine transmitters every 100m along a major highway re-charging your electric vehicle as it drives. Suddenly the 40Mi limit on a Volt becomes "40 miles off the highway". It would be a huge investment... but an end to internal combustion.
Interesting idea. I wonder how people would pay for the energy then? Would the car just have an onboard sensor that records when it pulled energy from the highway recharging system?
what is the maximum distance that a wireless electicity can serve?


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