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 for one hail our new glowing overlords

[debatem1 (1087307)]

I have to wonder whether this announcement and the glowing pigs announcement are just coincidental...

Wireless Everything

[ShawnCplus (1083617)]

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.

Re:Wireless Everything

[ByOhTek (1181381)]

well, I experimented with this. While the tumors were benign to me, after the third or fourth time I woke up to find one gnawing on the limb of a small child it apparantly captured/ate/killed, I decided it was time to have it removed. Apparantly three doctors were lost during the procedure.

Re:Wireless Everything - Oblig

[cybereal (621599)]

<governator>It's not a tumah!</governator>

is there a way

[JeanBaptiste (537955)]

to transfer power wirelessly without cooking whatever happens to pass inbetween the sender and receiver?

Re:

[gardyloo (512791)]

Probably. Just make damned sure that the transmitter produces frequencies which couple strongly only to the receiver (very small bandwidth). Things which don't resonate at those frequencies will be essentially transparent to the signals. I suggest 2.45 GHz!

Re:

[jdray (645332)]

From what I understand, it depends on the frequency. For instance, a microwave oven operates at whatever frequency best excites a water molecule, which leads to cooking by making the water in everything hot.

There was a long-running experiment in California back in the seventies or so that transmitted kilowatts of power over a few kilometers. They were doing the test as a lead-in experiment to figure out whether or not satellite-based power generation and transmission was feasible.

I'm not confident that we

Re:is there a way

[Otto (17870)]

From what I understand, it depends on the frequency. For instance, a microwave oven operates at whatever frequency best excites a water molecule, which leads to cooking by making the water in everything hot.

That is incorrect, but you're forgiven because it is a common misconception that's even in a few encyclopedia's and such.

Microwaves work by producing an alternative electric field (using non-ionizing microwave radiation) that acts on molecules which have electric dipoles. Water is one of those, but so are many others, including fats and such. The process is called Dielectric Heating.

Basically, the molecule being heated is a dipole. It has a positive charge at one end, and a negative charge at the other. In an alternating electric field, it rotates as it tries to align itself with the field. This causes motion, which translates to heat. The heat spreads as the molecules hit other molecules and transfer the energy to them. Now, this process works really good on water because water is a very strong dipole, but it does not operate solely on water, and it doesn't have anything to do with water in particular.

See, the frequency doesn't actually have much to do with it. Normal kitchen microwaves operate at 2.4 Ghz or close to that. Industrial microwave devices tend to work at 915 Mhz. Also, if the frequency had something to do with it, then 2.4 Ghz would be the wrong one. The resonant frequency for water is somewhere in the 20 gigahertz range. The only reason 2.4 Ghz is used for microwaves is that it's a free bands of frequency (ISM frequency bands) that can be used worldwide.

So, there you go. Now you know.

Re:

[Sarutobi (1135167)]

As long as we're getting in the scientifically correct... Frequency does matter. If the frequency is too high, the dipole won't be able to follow and you'll see other phenomena pop up. That is, for instance, why water is blue. The frequency of the electrons around the dipole allow them to absorb a bit of red light. If you go even higher, it will stop interacting altogether. If you go too low, the energy transfer will be hindered.

Re:

[Bill, Shooter of Bul (629286)]

sure power can be sent wirelessly a number of different ways, with outcomes other than cooking

• Sound waves carry energy, result: deafness
• Visible Light waves carry energy, result: blindness
• Positron beams waves carry energy, result: random explosions/ unexplained disappearance of electrons

Re:

[spun (1352)]

Couldn't we attach batteries to hamsters and let them carry the electricity where it's needed? Just set up hamster base stations with battery chargers and hamster food, and place small pellets of hamster food in the battery compartments of the device needing power. It's so simple and easy, I'm surprised no one has thought of this before.

Re:

[Stooshie (993666)]

... without cooking whatever happens to pass inbetween ...

Don't worry. If you wear a foil hat you will be protected!

Out of curiousity...

[Krinsath (1048838)]

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...

Re:Out of curiousity...

[mblase (200735)]

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.

If I remember my Second Law of Thermodynamics correctly, this is true in any case.

(Yes, I know what you meant.)

Re:Out of curiousity...

[tjstork (137384)]

All fuels take more energy to produce... in a sense, our present fossil fuel predicament is because we are using stored energy from the sun over millions of years. That we can even think about creating biofuels or really, any sort of fuel, efficiently, says a lot for how far the technology has come. But we'll never be able to just "create" a fuel, and the world's going to have to accept that.

Re:Out of curiousity...

[snowraver1 (1052510)]

200 years ago people would never fly.
150 years ago it was impossible to talk to someone in another town
125 years ago it was impossible to own a car
50 years ago it was impossible to own a computer (except for banks, schools, and gov't)

You never know what the future might hold. Cold Fusion might prove to be possible. Zero point energy might be proved and harnessed. Maybe someone will figure out a way to take the heat out of the atmosphere and make electricity from that.

My point is, and I do have one, that nothing is impossible. There is more that we don't know then we know... Chew on that.

Re:Out of curiousity...

[MBCook (132727)]

I'd think you'd have problems with RF, it'd be easy to waste power that way. The magnetic people mentioned in the article say they've hit 98.5%, which is great.

Re:Out of curiousity...

[Abeydoun (1096003)]

Here's the Wiki [wikipedia.org] I found on general wireless energy transmission.

From the wiki article

"WiPower [1] technology is a very recent example of inductive charging technology. The charging pad allow users to charge multiple electronic devices that are placed on its surface. It is insensitive to the position or orientation of the devices under charge. Unlike most inductive charging systems, the WiPower system uses air-core technology which allows the system to be integrated into very small electronic devices. The efficiency of the system actually exceeds many corded chargers which have a median efficiency of 57%."

I say neither, you say neither

[Ancient_Hacker (751168)]

Wireless power is not going to happen.

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.

Re:

[purpledinoz (573045)]

Maybe this is a good thing. I don't want my neighbour leeching my wireless internet AND my wireless power! Besides, I think a practical application of this would be as a laptop dock with no electrical connection. Place your laptop on the charging pad, and your laptop will start charging without having to plug in!

Re:

[farkus888 (1103903)]

it may not make a replacement for everything, but unless I am mistaken I have already seen electric toothbrushes that use something similar over very short distances. the advantage is they don't have to insulate any leads or connectors from the water it will inevitably be exposed to. a sealed case is always better than a sealed case with a rubber plug over the one opening where you give it power. range is not an issue because you are still dropping it into a charging dock [sitting it right on the transmitte

Re:I say neither, you say neither

[MBCook (132727)]

That's not wireless (RF) like he's talking about, that's inductive. It works on the same principal as a transformer. It only works under VERY short distances. If you lift your toothbrush out of it's charger by a 1/2", it probably won't work anymore.

An RF system would let you use the toothbrush without having it charged in a station. You could hang it from the ceiling with a piece of twine, turn it on, and let it run until something physically wears out.

I agree with the GPP, it's impractical. Inductive coupling (which I think is the same as magnetic being discussed) makes far more sense.

Re:

[Kintanon (65528)]

I swear I saw a proof of concept from a Korean company that was a desk where the surface was made out of some mat material they made. You plugged the desk/mat into the wall then it powered everything you dropped on it. They had a clock, a radio, and a couple of other little things. I would love for all of my peripherals to be charged/powered just by being in contact with my desk. That would be excellent.

Re:

[ghjm (8918)]

You were right - it's just that he doesn't have a low enough uid.

Re:I say neither, you say neither

[Jeff DeMaagd (2015)]

For the reasons you state, I'd put the people demanding wireless power among the people demanding pony-sized unicorns, at least for the forseeable future. I think pony-sized unicorns is more likely given how genetic engineering is going, but then the people that say they want them are going to say they won't pay more than $1500 for those.

Re:I say neither, you say neither

[Lumpy (12016)]

you dont need to shoot it across the room, just charge the device when set on a table. Make ALL your tables charging stations and now you attain the "wireless power" illusion.

I did this way back in the 90's for one of my EE projects. I created a charge mat and charge adapters to make devices charge from the mat. worked great, erased tapes , credit cards, and discs though... All you did was set the device down and it started charging. worked great and could supply 100ma of charge current to 3 devices.

April Fool's Day 2006

[Phroggy (441)]

Wireless Extension Cords [thinkgeek.com]

OMG, Ponies!!! [slashdot.org]

Inventions magazine, 1936

[by Anonymous Coward]

Good news everyone!

Radio-Fuel autos may solve gas problem!" [jalopnik.com]

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!

No more cords!

[Ngarrang (1023425)]

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?

arcing

[192939495969798999 (58312)]

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.

Re:

[desenz (687520)]

That isn't a problem if you're using RF or magnetics.

Magnetic is better

[MBCook (132727)]

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

When will people learn?

[Kuukai (865890)]

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.

Gyroscope

[COMON$ (806135)]

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?

Tough...No Easy Answer

[BoRegardless (721219)]

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".

Wireless power?

[Gavin Rogers (301715)]

Already invented. Next!

http://en.wikipedia.org/wiki/Tesla_Coil [wikipedia.org]

Re:Wireless power?

[thatskinnyguy (1129515)]

Even better than that, Tesla was able to power stuff at great distances. He was doing stuff like this as early as 1891. Really people ought to start giving Tesla his due and stop claiming his concepts for themselves. More on his wireless power experiments here [wikipedia.org].

omni directional power transmission?

[Original Replica (908688)]

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.

I like wires!

[jabjoe (1042100)]

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.

will destroys

[Thuktun (221615)]

will magnetic coupling destroys your HDD

Oh, noes! They be destroying my disks!

omnidirectional wireless power

[sluke (26350)]

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 [sciencemag.org] and here's [mit.edu] a link to the press release by the MIT news office (no subscriptions required).

It's called "WiTricity"

[replicant108 (690832)]

As I mentioned elsewhere, the BBC named it as one of the 'technologies of the year' - The technology with impact 2007 [bbc.co.uk]

Re:omnidirectional wireless power

[Big_Breaker (190457)]

Sorry but you have this one wrong - converting mains AC to 1mhz is very easy. A common switch mode power supply chops the 50/60hz AC from the wall into a 100khz to 1Mhz waveform with a common (but fast) MOSFET. The chopped signal is then run through a stepdown transformer. The transformer and ripple filtering capacitors in the second stage can be MUCH smaller and more efficient due to the higher input frequency. In this way the high frequency generation is effectively free for a wireless power system, since most DC converter will have a high frequency first stage anyway.

The resonant coupling is the hard part. Switch mode frequency chopping is bog standard.

It is simply a bad idea

[damburger (981828)]

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.

This sounds familiar...

[arotenbe (1203922)]

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?

Blu-ray!

The future?

[nurb432 (527695)]

I bet Tesla does not get any credit for doing it decades ago.

Pacemakers

[Stooshie (993666)]

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.

Re:Woah

[somersault (912633)]

For the types of application this is meant for, I think the old option would be a power cable. Unless you want to run your TV and computers from a few truck sized batteries. Seriously, when they brought out laptops did you say "JUST USE A DESKTOP!"? When they invented the telephone would you have said "JUST GO FOR A VISIT!". When people are walking into hospital do you should "JUST DIE ALREADY!"?

Re:

[ohtani (154270)]

Should I use batteries to charge my batteries?

Re:

[vanyel (28049)]

In a sense, we've standardized our "wired power connectors" with the 120V (US) outlets. The devices haven't standardized their power inlets though, so we have a bazillion adapters.

That would be the advantage of the rf method though: even if there were multiple incompatible formats, at least the device could pick up whatever it needed. You'd still have to carry the transmitters around unless they became ubiquitous though. That would be nice, but seems like the long shot, both for health concerns (valid or