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What is the Future of Wireless Power?
mfbatzap writes "According to Firdooze, we have seen various devices that can free ourselves from wires at CES 2008. The manufactures, Wildcharge, Powercast and Fulton Innovation, came out with two different methods of transmitting power from source to the devices. Wildcharge and Fulton banked on magnetic coupling while Powercast decided to go with RF (Radio Frequency). So which technology will eventually prevail to be the future of wireless power? Or will the technological setbacks from transferring power wirelessly make it unrealistic to accomplish a wire-free world?"
I have to wonder whether this announcement and the glowing pigs announcement are just coincidental...
JUST USE BATTERIES!
ilovegeorgebush
Well my laptop has wireless internet and a wireless mouse, why not wireless power? I'd gladly accept a benign tumor or two if I could get more than 3 hours out of my battery.
Excuse me while I gather the virgin sacrifice and assemble the pentagram required to solve your problem
to transfer power wirelessly without cooking whatever happens to pass inbetween the sender and receiver?
Does anyone know how much power is "wasted" (if any) due to using wireless methods versus wired connections?
Off my limited knowledge, it would seem to be akin to one of the problems with biofuels...they currently take more energy to produce than they store. So will using this technology to charge a device result in taking two or three times more energy to transmit the same amount of power to the device, or is there no discernible difference between wireless and wired?
Just wondering is all...
Shooting photons across a room to deliver significant power just ain't gonna be practical. If you use an omnidirectional antenna, the losses will be huge. If you instead have like a parabolic dish that tracks the receiver, the losses will be lower, but what happens to kitty or your eyeballs if they get in the way? Cooking your eyeballs to a nice firm egg-white consistency is not going to fly.
Magnetic fields are dipole fields, that means the little wavy lines leaving the North pole want to curl back as quicly as possible to the South pole. Which means they have very little extent in space. The strength drops off as the CUBE of the distance, so any significant distance is a no-go.
Wireless Extension Cords
OMG, Ponies!!!
$x='S24;r)>63/* h@<5+oZ)32"5cz';$me='phroggy'x$];
$x=~y+ -xz+\0-Tx+;print$_^chop$me for split'',$x;
Radio-Fuel autos may solve gas problem!"
All you do, you see, is you put this big coil above your car, and several gigawatts RF transmitters embedded in the roadway! Waste heat from the transmitters (and the melted tires, and the roasting humans) can even be used to ensure that ice never accumulates on the road!
Wireless power certainly should have a future if a single standard was achieved. It would be nice to be able to sit my child's toys near the charging station and have them charge themselves. No more fuss with changing batteries every month. No risk of losing the AC adapter.
And it can certainly be made efficient and safe by using a focus beam to the device being charged. We are surrounded by RF signals everywhere we go. What is one more RF signal?
Bearded Dragon
How do you prevent arcing with wireless power? Seems to me that wireless power pretty much means arcing through the air of some kind for any high-power applications... sounds dangerous in the proximity of the broadcast and receiving antennae.
stuff |
I'm not in the field. I'm not officially qualified to decide. But this is /.
Wireless (RF) worries me. You either have to confine it to a little beam (then why not just set the device down somewhere?) or pump a ton of power into it (most wasted). There are a few limited applications where it might make sense (the Wii, since we already know you'll be standing in front of the TV). I'm also worried about health concerns (really high frequencies can solve this, to a good degree) and interference (this is what I see as the biggest problem).
The idea of just setting a device down and having it charge seems good enough for me. It would work easily for keyboards and mice, cell phones, laptops, monitors, and many other thing. It's more efficient, and as the article mentions they can provide different amounts of power (like 5v to a cell phone and 12v to a hard drive). The guy who wrote the article worries about things like it erasing your credit cards or zapping you if you take a piece of metal near. This is easily solved by adding a tiny RF signal (like RFID) to detect devices. If you only supply power in the vicinity of that signal, then when someone sets a spoon down you won't fry them.
People have been working on this stuff for years. I hope they finally start getting it out there. It would be great to do something like be able to rearrange my desk (2 monitors, mouse, keyboard, laptop, other stuff) without having to bother plugging in or unplugging all those power cables. Add in a wireless version of HDMI or DVI or DisplayPort and all of a sudden things get really easy. But the best part would be being able to just put my phone on the counter (or desk or whatever) at night and have it change without me having to do anything. Very useful. Bigger batteries wouldn't be as important if you could easily charge devices anywhere and everywhere without having to carry and adapter and fumble for a free outlet.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
Wireless power was simply never meant to be. Nikola Tesla tried it, and look what happened to him. He's DEAD!
I wouldn't touch wireless power with a ten foot, umm... wire.
Sendou Wave Kick!!
Can someone explain if this is a matter of transferring electrons between two devices, eg the source and recipient of the energy? Wouldn't we be better off either A: improving batteries, or B playing with an source that creates an event that would cause a pendulum of sorts to charge a device?
CS: It is all sink or swim...oh and did I mention there are sharks in that water?
There is s vast difference between a universal wireless charging "surface" or "plate" where your electronics go at night versus recharging at a distance of 10 feet.
Then there is also a difference between the "idle" power loss versus "zero" while turned OFF & of the transmitters efficiency in getting power to a remoted device. I could imagine only 25% or less of the transmitter's input getting to the remote device.
Time matters. Batteries are going to get better quicker if A123Systems & others are right, meaning charging with a standard cord may be the cheapest & best method giving a 5-10 minute recharge, as opposed to overnight.
Ain't going to be easy. Lots of VC money is going to be burned up. The good news is the U.S. government is not picking and funding a single winner, as they tend to do when they back a "bill".
Already invented. Next!
http://en.wikipedia.org/wiki/Tesla_Coil
So where does the power go, that doesn't make it into the device? In this day and age of energy efficiency and conservation, this seems a step backwards. Maybe that energy is slowly heating the room or maybe it's slowly increasing my risk for cancer, but either way if the vast majority of the power isn't going into the device it's being wasted. Tis tech might have some specific applications where the wirelessness is of true overall benefit, but everyday hand held devices aren't it. As global energy demands continue to grow using something like this to charge your cellphone will become a hallmark of bourgeois ass-hattery.
We are all just people.
I want to see what is connected to what in a nice clear visual way, i.e wires. I want soild connections, i.e. wires. I want secure connections I could see no one else is using, i.e wires.
...which is probably the most harmful to human health, and which allows corporations the most ability to cut corners, maximize profits, and make off like bandits while people quietly contract leukemia.
Charging cable have a median efficiency rate of 57% as stated above. The magnetic solution has already been known to reach 98.5 efficiency. I would trust the RF power more than the magnetic solution, simply because magnet + credit card = 0.
With all the cancerous death rays bouncing around now, I have to ask - is there a possibility of major health concerns, and have they been fully examined? I just have some reservations about shooting electricity around my house.
I'm relatively pessimistic about both of the technologies mentioned due to the inherent limitations that they pose (large leakage of radiated power or short range). I'm looking forward to seeing products based on the wireless power idea that came out of the Joannopoulos group at MIT in 2006.
The idea was that you can setup an RF wireless power transmitter in such a way that it does not actually transmit any power unless it resonantly couples to a precisely shaped receiver. This way there is little to no leakage and they claimed that the power transfer was quite efficient. I'm sure this was posted to slashdot, but I can't seem to find it. Here's a link to the paper if you are somewhere with access to Science: Science 6 July 2007: Vol. 317. no. 5834, pp. 83 - 86 and here's a link to the press release by the MIT news office (no subscriptions required).
There is one of two ways you can get power wireless with RF radiation:
1. Send it out in all directions. Incredibly wasteful and, because of the inverse square law, has to be so powerful it will interfere with other stuff.
2. Send it out in a narrow beam. I really wouldn't want to be standing in between a laptop and an outlet if this were the method...
Either way, I prefer living in a home that isn't a microwave oven.
If we can put a man on the moon, why can't we shoot people for Apollo-related non-sequiturs?
Tomato wedge sperm darts that are Republican.
I bet Tesla does not get any credit for doing it decades ago.
---- Booth was a patriot ----
After all, it does work! I mean, I can't wait to have to set the WEP Key on my wireless power router! "Honey, why did the power go out?" "Wait, I'm going to reset the router!"
The focus shouldn't be on "wireless" power per say, but in general just absorbtion of energy which doesn't require a tether, AKA solar & etc. to an extent. RF may be possible but I'd be damn weary if there weren't some massive long term safety tests first.
One thing not mentioned (particuarly with the magnetic induction system) is how pacemakers are affected.
At least with MRI scanners there are notices everywhere about people with pacemakers. If these things become widespread people with pacemakers are going to have to avoid a lot of places.
America, Home of the Brave.
HOMER: That's right, Lisa. In THIS house, we OBEY the Laws of Thermodynamics!
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The problem with wireless power transmission is that it's hard to control where your electromagnetic fields go. They tend diverge as an inverse square law, scatter and bounce all over and be absorbed by things that are not your antenna. This is wasteful, because your wireless power ends up heating up trees, grass, and rivers rather than powering your city, and dangerous, because if a human absorbs even a tiny fraction of a gigawatt power transmission from a generation plant, he'll be cooked.
In recent years, engineers have come up with several schemes to prevent the scattering and leakage of electromagnetic energy. The most clever involves the use of a long strand of copper, which acts as a "guide" to shape and direct the EM fields and keep the power tightly focused and moving in the right direction.
Power over Glass/Plastic Fiber.
Thats the Future of Power Transmission.
All the rest are Losers Games.
If it don't GO... chrome it. ~ Frank Banks
As I mentioned elsewhere, the BBC named it as one of the 'technologies of the year' - The technology with impact 2007
Isn't this technology very wasteful, a huge proportion of the power must just escape into the air. I would not be too surprised if it ends up getting banned.
What's wrong with wired power, exactly?
Well first of all, the biggest untapped energy source on the planet still is an increase in efficiency. Why does my laptop need take 60 Watts of power in order to heat up my lap?
Why do we have displays in mobile devices that waste 5/6 of the light they generate?
Why do we still have processors that take _Watts_ of power althought alternatives with milliwatts are available?
I believe that a 1 Watt laptop-like device is definitely possible. It won't have a colour screen nor Windows Vista, but it would do everything you want it to do. Just look at old Psions which ran for months.
As I pointed out previously, there were at least three companies demonstrating wireless charging systems. This new article lists two more, Powercast and Fulton Innovation.
Short-range systems using long-wave near-field RF are probably the way to go. Power ratings can be quite high. The GM EV-1 charger used an inductive paddle operating at 400KHz, and could transfer kilowatts across about half an inch at 90%+ efficiency. The MIT system operates in the 4-10 MHz band.
One of the big advantages to this idea is not having to have a bazillian different wall warts for every separate device. Usually unlabeled so that 6 months later, you have no idea what goes with what if you haven't rigorously kept things together and/or labeled them yourself, not to mention having to lug around a few kilos of the things when you travel.
Except now they're going to beta/vhs us so some things need this charger and some need the other charger. If you get it wrong 6 months later, you've got a device you absolutely needed charged and you put it on the wrong pad, leaving you stranded high and dry.
The reactive field stays put quite nicely. If one could set it up without generating that pesky wandering radiating field...then we'd be all set. Who cares if it's a cube law device, if your not losing anything to radiation you can make the field as strong as you like. Sure, your uncle with the CABG might not like having the tie wires ripped out of his sternum but what do you care, you're in the will.
1. Spotlight
2. Photovoltaic Panel Wired to Laptop Battery
3. ????
4. Profit!
Comment removed based on user account deletion
Someone will hire a company to implement this. This company will have a very stubborn, self-righteous president, but it will manage to get a working solar satellite into space, along with a terrestrial reception station. However, efficiency will not be as high as expected. Eventually a decision will be made to cut public spending on this technology, and the president will say, I quote: A few days later, everyone will be weeping over the catastrophe caused by a mysteriously misaligned microwave beam. The president of the company will be nowhere to be seen, but his name will start appearing unusually frequently in pump-and-dump stock scams.
"Let's face it, it's a good story. Accuracy would kill it."
An average laptop consumes about 50 watts. Using the back of a 15" screen as receiver (0.07 m^2), the intensity is about 50 / 0.07 = 714 watt/m^2. As a reference, "a site in Eastern Oregon receives 600 watts per square meter of solar radiation in July". http://zebu.uoregon.edu/disted/ph162/l4.html > See, it's just like walking by an unshaded window in a summer's day.
It's not a tumah!
I read the script, and I think it would help my character's motivation if he was on fire. -Bender
You wireless naysayers are all a bunch of T.A. Edison lackey fan boys! Bet you would like to see main power transmission switched over to DC too! Bah!
:-P
I don't even understand why there's a question. Magnetic coupling is a joke, sure it's efficient, but really, is it ALL that different from a form-fitting cradle with physical contacts? You still have to put the device within inches of the charger... are people REALLY that lazy that they won't go the extra inch? I have an electric toothbrush that just sits in a cradle every night, I don't even SEE any physical contacts, and it's a good holder, so why bother? Or how about Apple's magnetic plugs, that's another great solution that is ALMOST as usable as magnetic coupling.
RF, on the other hand, is a revolution. It has the potential of charging and powering from long distances. Imagine, 150 years from now, aircraft which are electronically powered BY THE CONTROL TOWER. Sure, it's a pie-in-the-sky right now, but a theoretical possibility. An even more viable application would simply be cell-phones that just continually get a charge from cell towers, and don't have batteries, or have very small ones. Magnetic coupling can't dream of doing that.
When I was in my teens, at some point, I got the idea that something could be powered by radio transmission, but I was promptly told that that wasn't physically possible. So you can imagine that, at least for me, this is one of the most exciting scientific pieces of news I've heard in months.
Multiplayer Gaming (defined): Sitting around, discussing single-player games with my friends, at the bar.
Sometimes I can't help but think that if Tesla had continued more of his experimental research into very high energy RF transmissions that he might have learned about its hazards similarly, and personally, much in the same manner that Marie Curie learned the hard way about the hazards of working with radioactive substances without thorough understanding and laboratory safety.
Remembering back to physics, induction is different from resonance energy transfer, right?
So are these technologies distinct from the magnetic resonance transfer used by the MIT lab last year? Resonance transfer seems like the safest and highest efficiency method for wireless transfer over short distances, to me. (In that it doesn't lose much energy to those bothersome things between source and destination...such as human beings)
If you can't find a real troll, just mod down whoever you don't agree with!
The thing I'd really like to see wireless power for? Transportation, by building this system right into the roads and billing your car for the amount of electricity used. Cars would be lighter, reducing the amount of electricity that would be required to move the vehicle. This would also eliminate the need for batteries meaning unlimited range. I'd be interested to see what would happen to automotive design if the power plant of a car was no longer necessary.
The only problem with this is the engine/batteries are all that keep some cars on the road on very windy days, and trucks pulling weight would have to some mass to maintain traction.
Why wasn't this story tagged with "whatcouldpossiblygowrong"?
Doesn't this seem dangerous.
We still don't know whats wrong with the bees do we?
This can charge all my wireless devices AND cook a hot pocket right on my desk?
I'll take 3.
Instead of comming up with that new magic device. Just suck all of the RF out of the air in an efficient manner and you can keep all your stuff charged all the time. If someone could invent a device to grab every frequency it sees efficiently, it would be perfect. If you need to charge your PDA, just walk near the kitchen and catch the runaways from the micro. If you need a boost, just sit at Starbucks and steal all the cell phone and WiFi energy. It is almost like a free natural resource!!
I can see a HUGE market for those.
Or ponikeys, for the guys.
Isn't it enough to know that I ruined a pony making a present for you?
You are not a brain: http://books.google.com/books?id=2oV61CeDx-YC
I don't think so. That's a page off the OLPC wiki, it says that laptops average about 20 watts idle. This is closer to my experience.
On an IBM T-40, the power measuring tool that comes with the computer (software) shows the laptop will use between 16 and 18 watts on lowest power consumption and up to about 25 with everything maxed and some peripherals plugged in (wi-fi, usb-powered hard drive).
On a friend's macbook pro: I think the system normally runs around 20 watts, and will use 11-12 W minimum and 40 to 50 max. This is a modern model: the latest, highest end one released, not including these new ones that will be coming out in a few days.
Here's another link. They estimate laptops average 10 watts, and I suppose your laptop would draw less ehile you were pedaling their generator (the laptop being idle).
I just want to tell everyone that 50 W is a bad number to assume for laptops, and 20 W is much better, and google is your friend.
Do not attribute to malice that which can be easily explained by incompetence.
It is obvious this won't work
Whenever the bridge of the Enterprise gets hit, sparks fly. This indicates wires....
I don't think I can live in a future that isn't supported by Star Trek Facts.
Unless of course, in the next 500 years, we have wireless power, realize it causes mutations, then revert back to ancient technologies. That I'll buy.
Both of the methods are far from perfect.
Magnetic is more efficient, but only if transmitter coil and receiving coils are extremely close one to another. It is in an essence flat "air core" transformer.
RF is more flexible, works on distance but it is terribly inefficient: it is difficult to efficiently produce powerful electromagnetic waves, RF is difficult to turn into controlled DC voltage needed to power electronics in efficient manner, and it is impossible to focus all RF energy into the beam.
Apart from that batteries / electronics need regulated current / voltage to charge / work so both methods need a way to rectify AC into DC and control it levels.
It is in essence a trade off: efficiency for "cordlessability".
I hope someone ignores the assholes who modded me down and gave me shitty karma... Would someone else please read this article, and not count the author's biases against jews against his integrity? http://www.vialls.com/wecontrolamerica/peakoil.html (the page renders funny for me, except when i set Opera to user mode) it talks about how the west drills oil wrong and russia figured out the truth. It came off as the best conspiracist theory ever at first but as I read on and thought about it, it seemed plausable. if anybody does read this article email me your thoughts because no one i talk to likes reading long articles... -jakepmatthews@gmail.com
I suspect the standby losses will be more than the 500-750mW allowed by efficiency standards. These standards were set to challenge the manufacturers of conventional wire-connected power supplies. To meet them, the engineers must reduce losses wherever possible. Copper conductors can deliver power to the load device with efficiency better than 95% (less than 0.25V drop for a 5V adapter, etc.). Wireless couplers would be hard pressed to come anywhere close to that. It seems like a step backwards in the battle against wasted electrical power.
"So which technology will eventually prevail to be the future of wireless power?"
Why assume that one will win out over the other. There are likely to be circumstances where neither are going to be suitable (but a third method is), or where one is ruled out for some local reason. Or just possibly, someone will combine both systems into one device that (say) fits under a desk surface and that takes off with both.
Magnetic induction is going to need current-turn-square-metres, so be more suitable to devices with a substantial footprint (keyboards connected to a processing device, for example) ; radio antennae on the other hand can be fairly linear, suiting your "pen format" memo recorder. Different courses, different horses.
Then again, perhaps the cheapest and most flexible form of wireless power would be a 3rd-world orphan with a hand-cranked generator. Just pour some slops from the kitchen into one end from time to time. Just make sure to get it neutered at the vets, unless you're planning on setting up a breeding programme.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
Waldo Farthingwaite-Jones? We do not want a "DeKalb receptor" failure situation.
Well I've wrestled with reality for thirty five years doctor, and I'm happy to say I finally won out over it.