Wireless electricity? It's here
cnn.com
cnn.com
LOL. power transmitted by a Wifi router ~= mW. Power required for, even a low energy light bulb ~= 10W. The current draw in modern homes is so big that EM transmission, especially at sensitive wavelengths like microwaves, is highly likely to cook things (and people).
They may well have found a real way to make it work. But saying "it's the same as wifi" shouldn't convince anyone.
The other aspect that wireless power folks face is that any conductor now has a much more serious voltage potential on it. This can cause weird things to happen when dissimilar metals are suddenly energized. Electro transport can cause otherwise strong welds/connections to vanish.
I sympathize with the need to find a way to explain how this could be safe, but they're stretching the truth. I hope it doesn't come back to bite them when somebody puts up a youtube video of cooking eggs on copper foil or something.
Count me as a wireless electricity skeptic, in general. But this claim is astounding to me.
I believe that if you placed a properly resonant circuit into an MRI device, for example, you could charge a decent sized battery (but probably not a vehicle propulsion battery) at a reasonable rate.
But it would be horribly inefficient and your car (and everything else in your garage) shouldn't be made of ferrous metal.
Cell phone batteries on little charger pads, sure. Maybe even via ambient EM, though I'm not convinced you could get regulatory approval above a certain emissions level (which, critically, has an inverse-square relationship to available current delivery capacity at the device).
But the article also talks about lighting and televisions, and cars. WiTricity has investors to fluff, clearly, but is this not absolute crazy talk?
> But the article also talks about lighting and televisions, and cars. WiTricity has investors to fluff, clearly, but is this not absolute crazy talk?
They've apparently already powered lighting, and the TED talk supposedly had them powering a TV [0]
[0] http://www.ted.com/talks/eric_giler_demos_wireless_electrici...
But it's still a super high powered magnet. There are more places than not where that's just a bad idea. Garages are high on that list. Also carports, kitchens, living spaces in general...offices, sleeping spaces..bathrooms. All bad.
LED lighting gets you pretty far down the current draw curve, but I don't see a small, easily moved coil generating enough resonant current to be useful in many common consumer electronics. That coil has to be plugged in to the mains, remember -- invalidating the promise of wireless power, even at three feet.
And ambient charging has all of those problems, squared.
I have a hard time getting excited about these guys' work, but will readily admit they are excellent about generating publicity. There is a lot of _very_ closely related work in resonant energy transfer and use of time reversal or lensing currently being looked at around academia. Hopefully one day it will pan out, but it is never going to be as efficient as running a wire. For some applications wireless power is a great enabling technology, but powering a light or a tv in your home? That's a hard sell for the "convenience" of moving your tv versus the extra costs in energy inefficiency.
I would put in a few more safety methods.
http://www.draysonracingfe.com/technology.html?Wireless-Char...
It gets charged via induction. Fifth Gear recently had a segment about this where you could briefly see the black flat device they park it over.
edit: pic: http://www.draysonracingfe.com/technology.html?Wireless-Char...
Of all the silly things one could do with "wireless" electricity, charging cars is probably one of the better applications.
I believe this is in use since quite some time for charging equipment like forklifts, busses on fixed lines, etc.
They would provide power only to the area of space where the receiver is which first and foremost makes it inherently safer than a system which doesn't focus the power. I'm not going to claim I know much on the topic, but intuitively it would seem that the ambient power produced by the pcell transmitters would scale logarithmically with the power being transmitted.
But I trust that Witricity's produce is safe for most people since these things are highly regulated for safety. Perhaps more important to adoption is that the nature of Witricity's technology makes it impossible to selectively transmit power. Therefore, it would be impractical to charge a fee for using a power source. Pcell can do this, because it has to to be useful as a cellular technology.
I don't see a world where electric cars are charge wirelessly by beacons on roadsides, not at current electricity prices and the loss that would be involved, but I can imagine low power devices such phones and laptops becoming much more elegant through wireless power.
http://www.witricity.com/pdfs/highly-resonant-power-transfer...
http://www.instructables.com/id/Build-an-antique-style-cryst...
You can use a Crystal radio to power an LED, or a lot of things, the stronger the RF source, the more power you can extract. The problem is they aren't efficient if you are using them as a power source. When you are pulling "free" energy out of the airwaves they are cool, all that wasted AM band, but if you are broadcasting just to power your cell phone they are about .1% efficient. That's not a very eco-friendly.
A wireless dog leash would be nice too.
But I'm not holding my breath. I'm also a little worried about efficiency.
Anyway without a solid power source WiTricity would seem to be kinda non applicable for larger areas, but it's still good enough for small home chargers and stuff.
From what I remember about Tesla claiming that he would either use the ionosphere as a way to either amplify or bounce the signal. It's hard to separate fact from fiction with that man.