Intel Claims an Advance In Wireless Power

Many readers are sending in coverage of a demo at Intel's developer forum of a wirelessly powered 60-watt bulb. The NYTimes gives background on Intel's improvement to the 'wireless resonant energy link' technology pioneered at MIT, where researchers achieved 50% efficiency of power transmitted several meters via magnetic fields. Intel reached 75% efficiency. Now they just have to make those coils a lot smaller.

Comments

What a waste of energy

[Timo_UK]

25% of wasted power and goal achieved? Plus a nice pulsating magnetic field in the house? No thank you.

Re:What a waste of energy

[MightyYar]

Plus a nice pulsating magnetic field in the house?

They'll sell more if they say it's "throbbing".

Re:What a waste of energy

[poetmatt]

This is not a new technology but it is helpful to have refined, although the first use when the technology matures will be short range devices (1-2ft) not long range devices (10-20ft).

A4tech made a series of wireless battery free mice that use the same technology (I've been using those for about 4 years)....they were cheap pricewise too. A4tech appears to have lost their sql server/domain (at a4tech.com), so I'm linking one from a shopping site:
http://www.ecost.com/detail.aspx?edp=39484911

These types of things are actually really nice, it makes the mouse extremely lightweight as well.

However, I seem to recall people saying the wireless transmission aspects will enable to create a "charging pad" whereupon you can place any device and simply charge it without having to connect it, and thus would be the basic use - put an ipod, a phone, whatever on said pad and charge ahoy.

Re:What a waste of energy

[beacher]

I've used these wireless extension cords and they don't have the throbbing noise. Just don't walk between them.....

Re:What a waste of energy

[MightyYar]

In addition to my snarky comment, I have a serious one.

I can think of a number of uses that are worth the wasted power. One would be wirelessly charging at airports, coffee shops, etc. Another would be prosthetics... Imagine if you had a motorized leg or arm and could set up a charging coil near your desk so that you're nearly always "topped off". You could even have the coil power down when not in use so that these "pulsating magnetic fields" don't worry the fickle masses.

Re:What a waste of energy

[sm62704]

You already have pulsating magnetic fields in your house. In the US, AC current is 60 hz, so you have a constant 60 hz magnetic field. That hum you hear is the oscillating magnetic field moving steel back and forth.

Your TV has a tremendous magnetic field, as do subwoofers.

The magnetic field won't hurt you. My dad was an electrical lineman for forty years, often working on the 30,000 volt towers. He couldn't wear a mechanical wristwatch because it would become magnetized. He just turned 77 and he's healthier than a lot of guys my age.

If magnetic fields caused cancer, linemen would die of lukemia right and left.

Re:What a waste of energy

[thebigmacd]

Don't forget too, that the earth is a giant magnet with a very powerful field. Granted it is fixed (not alternating) but still...

Re:What a waste of energy

[NoPantsJim]

Try and add it to your cart and it'll show the proper power output.

Re:What a waste of energy

[DoofusOfDeath]

He just turned 77 and he's healthier than a lot of guys my age.

You're new here^h^h^h^h to statistics, aren't you?

Re:What a waste of energy

[Doc Ruby]

We've already got enough wasteful energy tech "byproducts" heating the air without converting 25% of our mobile power into hot air in our homes and offices. That needs to be airconditioned away, which itself operates at something like 20% energy efficiency, so that extra 25% will cost an additional 125% in cooling power. The 75% used for charging will consume an extra 150%, so the whole affair will consume 3x the power it delivers to devices, for 33% efficiency, not 75%.

And if the chargers are on all the time, they're going to be wasting that extra energy all the time, the way wired adapter chargers do now. All those "always on" chargers use a significant percentage of the world's electric for no benefit whatsoever.

We should be working on tech that reduces these electric wastes, not multiplies them. We don't have enough energy to waste now, let alone to waste many times more.

Re:What a waste of energy

[ShieldW0lf]

Tesla wanted to do this on a large scale over a hundred years ago, and was prevented by his investors because there was no way to meter usage. He filed a patent for his concept in 1900. This technology is crippled and extremely late.

Re:What a waste of energy

[chaim79]

I think that's one of those "april fools" items... note the availability of it.

Re:What a waste of energy

[Lumpy]

Exactly. My design back in 1992 had zero waste when an item was not near the mat. (I invented the "charge mat" for my final thesis for my EE degree.)

I simply looked for a change in inductance to detect if a device is local for charging, if so I switched from detect to charge and pulsed back to detect every minute. Also I did not have a 25% loss, but I was only supplying 10watts. (I was charging devices not powering them.) From what I remember losses went up ad the power range went up. Plus I used simple inductance not som fancy phased power system.

Side effect, keys on the mat will get warm, floppies and zip disks erased.

Re:What a waste of energy

[querist]

That 60Hz is also a good B-flat in case you need to tune a musical instrument.

Re:What a waste of energy

[SQL Error]

Tesla wanted to do this on a large scale over a hundred years ago, and was prevented by the laws of physics.

Re:What a waste of energy

[aliquis]

Or maybe it was just considered a bad idea, and I think it's now as well.

Re:What a waste of energy

[vsage3]

This is not a new technology but it is helpful to have refined, although the first use when the technology matures will be short range devices (1-2ft) not long range devices (10-20ft).

Actually it IS a new technology. Anyone who is spouting off bombast about how Tesla came up with this a hundred years ago, or that we've been using this in transformers for years is WRONG. Transformers are not resonant devices and rather rely on the closeness of the windings/core to guide the majority of the field lines to the other winding. As for Tesla's work, he used strictly far field EM radiation, which differs fundamentally from this effect, which uses near-field interactions that tend to "stick" for lack of a better term to the power source unless transferred to another device capable of resonating with it. This is what makes this 2006 discovery so great because it is extremely efficient and doesn't rely on line of sight or broadcasting a huge amount of power so that a device a reasonable distance away can receive the power it needs to operate. According to the 2006 article ( http://www.sciencemag.org/cgi/content/full/317/5834/83 ) the electric fields involved are small too: around 200V/m which is about double Earth's field at ground.

And finally, The human body has little to no magnetic response which is why MRI's don't kill you with their multi-Tesla magnetic fields (the Earth's magnetic field is 0.5 Gauss = 1/20000 T, for reference)

Re:What a waste of energy

[AJWM]

Linemen also spend more time in the sun, are more likely to be exposed to PCB residues from transformers, and are exposed to chemicals like arsenic and creosote used as preservatives in wooden poles.

Re:What a waste of energy

[ShadowBlasko]

This is not a new technology but it is helpful to have refined, although the first use when the technology matures will be short range devices (1-2ft) not long range devices (10-20ft).

Keep in mind that there are already quite a few of these in use today. My Sonicare toothbrush has no external contacts or wires, and charges quite well in its base. Recently I discovered that it will also charge if you just stand it *next* to the base. Pretty cool tech if you ask me, I just hate the fact that I cant replace the Li batteries (which are exactly AAA size) when they fail.

Re:What a waste of energy

[orasio]

In 1920 the patent expired.
Maybe it wasn't done before, because it couldn't be done practically.

About being "extremely late", that is funny. Going to the moon in 1969 instead of 1900 was also extremely late, Julius Verne had already thought of that.

Re:What a waste of energy

[ShieldW0lf]

Tesla wasn't a hacker like Edison. He was a visionary, who saw deeply into the inner workings of the universe at an intuitive level. He captured what he saw in the language of math, and created the foundations for the modern electric age almost singlehandedly. The HAARP project in Alaska is based on his work in this field.

If he said it was possible within the laws of physics, personally, I believe him. He was probably the most important man in history.

Re:What a waste of energy

[mrops]

Tech Support: This is tech support, how may I help you.

Customer: I powered my Wireless USB Harddrive with this nifty Wireless power thing from Intel, My Harddrive is not showing any data, in fact my computer says the drive is not even formatted.

Re:What a waste of energy

[encoderer]

IIRC (And I may not), he set up a big demo for the press. They all trekked up to his compound. He flipped the switch and it APPEARED to work. And a bird apparently flew into the path of the transmission and the bird just fell like a brick, as if it died instantly.

Many people speculated that it was a hoax or, if not, it was at least very dangerous.

The story goes further that when he died, the Gov't confiscated his papers. US Scientists looked everything over and concluded it to be impossible.

Then, during the cold war, US Spy imagery showed a huge complex being built in a remote location in the USSR. The military had trouble figuring out what it was. Eventually a Gov't scientist familiar w/ the Tesla work had the 'aha moment' and he pulled-out the tesla papers and sure enough, it seemed as though the Soviets were building an energy weapon of some sort.

Again, IIRC, they never were able to make it work, which is why it's not famous and in school books. But it is interesting that they TRIED and I'd love to read about that project.

(Heard all this about a year ago on a radio program by either NPR or PRI)

Re:What a waste of energy

[encoderer]

Here: The actual story I was referencing is the last one on this page. I remember it being a "driveway moment" for me -- I got home, and sat in the driveway until the story was over.

(I had trouble w/ streaming -- but I clicked the "pop out" button and there's a download link from there. It's just an MP3)

http://www.studio360.org/episodes/2008/01/25

Re:What a waste of energy

[binaryseraph]

Plus a nice pulsating magnetic field in the house?

They'll sell more if they say it's "throbbing".

Only if they are selling to women.

Apparently you have never come here to San Francisco.

Re:What a waste of energy

[mutende]

That 60Hz is also a good B-flat in case you need to tune a musical instrument.

Really? I thought it was a high F#. Or at least that is what it sounded like when my retarded half brother stuck a fork in the light socket.

How Acoustic Guitars Work shows that 120 Hz is in-between B and A#, and 60 Hz is exactly one octave lower than 120 Hz.

Re:What a waste of energy

[Anonymous Coward]

Fanatics? No.. realistic. Tesla has been regarded as "The Father of Physics", "The man who invented the twentieth century" and "the patron saint of modern electricity." He's far from being a 'crackpot who got lucky'.

Inventions include:

Electromechanical devices and principles developed by Nikola Tesla:

        * Various devices that use rotating magnetic fields (1882)
        * The Induction motor, rotary transformers, and "high" frequency alternators
        * The Tesla coil,[31] his magnifying transmitter, and other means for increasing the intensity of electrical oscillations (including condenser discharge transformations and the Tesla oscillators[32][33])
        * Alternating current long-distance electrical transmission system[34] (1888) and other methods and devices for power transmission
        * Systems for wireless communication (prior art for the invention of radio) and radio frequency oscillators[35]
        * Robotics and the "AND" logic gate[36]
        * Electrotherapy Tesla currents[37][38][39]
        * Wireless transfer of electricity and the Tesla effect[40][41]
        * Tesla impedance phenonomena[42]
        * Tesla electro-static field
        * Tesla principle
        * Bifilar coil
        * Telegeodynamics
        * Tesla insulation
        * Tesla impulses[43]
        * Tesla frequencies[31]
        * Tesla discharge[31]
        * Forms of commutators and methods of regulating third brushes
        * Tesla turbines (eg., bladeless turbines) for water, steam and gas and the Tesla pumps
        * Tesla igniter
        * Tesla compressor
        * X-rays Tubes using the Bremsstrahlung process
        * Devices for ionized gases and "Hot Saint Elmo's Fire".[44]
        * Devices for high field emission
        * Devices for charged particle beams
        * Phantom streaming devices[45]
        * Arc light systems
        * Methods for providing extremely low level of resistance to the passage of electrical current (predecessor to superconductivity)
        * Voltage multiplication circuitry
        * Devices for high voltage discharges
        * Devices for lightning protection
        * VTOL aircraft
        * Dynamic theory of gravity
        * Concepts for electric vehicles
        * Polyphase systems

http://en.wikipedia.org/wiki/Nikola_Tesla

No matter if the 'Tesla fanatics' know much about physics or not, Tesla still was and remains a very rare genius.

Thank you for trolling!

Re:What a waste of energy

[Hyppy]

Have you heard of that thing called "world", of which your country is only a small part... ;-)

In many parts of the world, you only need to remove the heat for 3 or 4 months out of the year... waste heat isn't wasted in the winter.

Re:What a waste of energy

[zuzulo]

Actually, these days physicists commonly think that Tesla was actually trying to use the (relatively static) magnetic field of the earth as a carrier for pulsed power. This turns out to be not quite as far fetched as it seemed at the time, and may actually be feasible.

Much like the difference between AC and DC current in copper (AC is significantly more effective because it essentially vibrates electrons back and forth rather then sending them all the way along the conductive medium from source to target), theoretically one could 'ring' the magnetic field of the earth with a large enough installation and appropriate frequency controls, and local power stations could use that 'ring' or oscillation to do work.

Much like how the AC power grid works today, except you are using the earths magnetic field to transfer energy between remote locations rather than our power grid, which is essentially a huge network of copper wires.

So it is not at all clear that what stopped Tesla was actually the laws of physics, it could have been any number of things and the basic idea may actually be sound.

These days if anyone is playing around with trying to manipulate the earths magnetic field, even for altruistic goals, i hope they think about the potential seen and unforeseen side effects. Which despite his genius Tesla clearly did not generally do. No one really knows as yet (to my knowledge, anyway) what the long term effects are of exposure to large and/or rapidly fluctuating magnetic fields. Heck, we still dont know what the real biological effects are of various electrical fields.

Upshot: not at all clear that Tesla's scheme to implement wireless power on an extremely large scale was stopped by the laws of physics - the possibility of something similar to his designs being able to accomplish some part of his goals still appears to be a real potential.

Re:What a waste of energy

[ColdWetDog]

I just hate the fact that I cant replace the Li batteries (which are exactly AAA size) when they fail.

Sure you can - meet Mr. Dremel Tool. Use one of those nice, thin cutting disks and cut the bottom out (or the side on some of the newer ones). Replace the battery. Seal using weatherstripping cement or similar.

For extra credit, attach a mini web server to it and have it start a conversation with your toaster.

Re:What a waste of energy

[aztektum]

His name was not Julius.

Re:What a waste of energy

[Poltras]

I never signed anything.

Re:What a waste of energy

[Anonymous Coward]

PinkyGigglebrain posting as AC because I'm at work and don't remember my password at the moment.

As a Hacker I am trying not to feel insulted. Edison wasn't a "Hacker" in any sense of the word. He didn't do something just to see what would happen or if he could do it. Edison was a business man who would only work on something if he could make money from it.

In regard to the gp, it wasn't physics that stopped Tesla's energy transmission research, it was people like J.P. Morgan pulling the financing because they where making money from selling electricity sent through wires and didn't want Tesla to rock their boat with "free energy you can pull from the air".

Tesla was not just a visionary, and a pure Hacker, he was a Creator. His ideas where so far beyond what his contemporaries could imagine that most of his work was ignored, try looking up "Tesla Turbine" on utube, 70% efficiency but so "out there" in its simplicity that the engineers I know think its a joke until they see it working.

People like Edison could only build on what others had already done, the light bulb existed for years before he made it commercially viable, dito for the phonograph and movie projector.

I fully concur with the parents post about Tesla being one of the most important men in history. At the very least he was the greatest Hacker/Creator/Visionary of the 19th, 20th and 21st (so far, we NEED someone like him right now).

Re:What a waste of energy

[hedwards]

Sure it was, he and Orange Julian used to hang out all the time with corporal Saunders.

Re:What a waste of energy

[geekoid]

" nner workings of the universe at an intuitive level"
What a stupid statement.

"and created the foundations for the modern electric age almost singlehandedly"

True. OTOH, there where others very close.

"The HAARP project in Alaska is based on his work in this field."

well since he invented device to use electricity in a very basic way, a lot of things are based on his work.

"If he said it was possible within the laws of physics, personally, I believe him"

Except no one can take is clear information and make it work.

"He was probably the most important man in history."
meh.

Genius? yes. He was also obsessed, and obsessed people, especially smart one, tend to buy into things with no real evidence.

He didn't know everything about the universe, and he didn't even know everything about electricity.
He did figure a llot of cool shit out.

Re:What a waste of energy

[MadnessASAP]

That's something totally different then a system that charges a battery wirelessly. That device induces a current in an inductor which THEN charges a battery. The device still needs to be modified to include an inductor. Also such a device will still produce an alternating magnetic field which could potentially damage a hardrive.

PS. It's also worth pointing out that any other inductors in the vicinity will also have a current induced in them which could potentially damage other devices, or at the very least cause undesired effects.

Re:What a waste of energy

[ShieldW0lf]

"Inner workings of the universe at an intuitive level" What a stupid statement.

Except that it wasn't. You have an understanding of the universe based on a bunch of abstract systems that were spoon fed to you. This guy figured it out by looking at the world with wide eyes, understanding it, then putting that understanding into practice.

To quote PBS on the subject, contrasting Tesla with Edison:

That's where the similarity ended. Tesla relied on moments of inspiration, perceiving the invention in his brain in precise detail before moving to the construction stage. Edison was a trial and error man who described invention as five percent inspiration and 95 percent perspiration.

The man understood things by creating a model of the universe in his head and achieving a Gestalt moment, where he saw the coherence of everything and the consequences that implied. This is very different from how most people think, and is a big part of the reason why he has a cult following among those who see those qualities to some degree or another within themselves.

Re:What a waste of energy

[Anonymous Coward]

You are conceptually misunderstanding the significance of this research. They are using resonant induction. This is a form of induction which has directivity determined by the load's location. Your design had excellent efficiency because the load was extremely close. Using resonant induction, you can have extremely high efficiencies with a significant distance between the source and the load. It does not radiate in unwanted directions--it would probably not erase a floppy because it would not couple to the floppy, it would only couple to the load.

Re:What a waste of energy

[Myrddin Wyllt]

He makes perfect sense. Transmission losses are lower for DC at equivalent Voltage/Current because of inductive losses with AC. Historically this has been offset by the greater transformer losses incurred by DC, but modern equipment means that, for long-distance power lines, HVDC is already more efficient than traditional AC distribution.

I've always wondered...

[sm62704]

With all the EMF in the average home, with AC wires in every wall and appliances always running, and as little power as a calculator or wristwatch uses, why they need batteries? It seems like a coil and a rectifier circut should be enough.

I'd probably know why if I were an electrical engineer.

alternative

[spectrokid]

how about all manufacturors agree on a single plug for their power supplies. Then the companies who make power sockets for offices can make one built into a wall socket. Put that into every meeting room. Suddenly you just need a 1 meter long, very thin cable instead of a lugging a whole kilo of copper around....

Re:alternative

[kent_eh]

PleasePleasePlease, someone with mod points mod up the parent.

I've been ranting on standardizing accessory connectors for years.
At least some cell phone companies are slowly moving in that direction, using USB for charging.
Now if only others would jump on-board. Cameras and MP3 players for instance. They already have the USB connection, how hard would it be to have it charge the damn battery?

Re:alternative

[SpacePunk]

Now, that's just crazy talk.

Re:alternative

[RulerOf]

how about all manufacturors agree on a single plug for their power supplies

This doesn't even happen within a single manufacturer. Every time LG makes a new phone, for example, the charging port changes.

And guess what? They do this to make more money. When you lose (or break) your (very shittily designed) charger, you can't just go to Radioshack and buy a $7 universal one. You have to go back to the manufacturer and pay $30 to get a new one.

Even chargers based on a worldwide standard are locked out on a manufacturer basis as well. Try plugging a Blackberry USB charger into a Motorola USB charged Verizon phone. It'll read "Unauthorized Charger." Not "Incompatible," but "Unauthorized." That means that the manufacturer (and probably Verizon, because they just know you'll show up at a store to buy their overpriced replacement shit) has decided that you'll only charge your phone with equipment that they deem fit to perform the task, despite the device's adherence to a worldwide open standard.

In short, you've got a fantastic idea, but greed-driven economics dictates otherwise.

I knew it

[Unclenefeesa]

There had to be some truth in emails I received about cooking an egg between 2 cell phone !!

This is new?

[amdpox]

Unless I've misunderstood the linked article, this is just the same technique that has been used in transformers for decades - a fluctuating magnetic field created by an AC current through a solenoid inducing power in another solenoid. Sure, 75% efficiency is pretty good for a few metres, but those coils are bloody huge. Anyone care to enlighten me as to whether or not this is actually new?

Re:This is new?

[Dunbal]

a fluctuating magnetic field created by an AC current through a solenoid inducing power in another solenoid .... Anyone care to enlighten me as to whether or not this is actually new?

      This one kills pigeons!

Ok, Slashdot team goal.

[Chairboy]

Alright everyone, today's team building exercise will be to complete this discussion without mentioning Nicolai Tesla! Everyone, let's get together on this and try to avoid mentioning him in this thread and keep it entirely Tesla free! ...oh goddamnit.

and the day after the tech goes live

[petes_PoV]

Pressure groups start campaigning about the health effects of bodily exposure to magnetic fields.

unlike the scares surrounding the micro-power electric fields from mobile phones and the virtually non-existent fields from CRTs, the amount of power being emitted by these (enough to power a laptop or lightbulb) might actually be something to get concerned about.

Re:We're still playing catchup with Tesla!

[Tenrosei]

Nah Tesla made something better he realized wireless power was stupid but wireless power that is a weapon is smart. http://www.newscientist.com/article/mg17623644.800-tesla-and-tunguska.html

Tesla did this a long time ago.

[kobotronic]

Nikola Tesla demonstrated wirelessly powered fluorescent lights more than 100 years ago.

Nevertheless, it would be interesting to see practical applications and commercial implementations for this old idea, and hopefully help us reduce cable clutter a bit. I just hope that accidentally resonant circuitry in the vicinity of transmitters won't suddenly fry itself and cause random fires.

Re:Tesla did this a long time ago.

[Anonymous Coward]

As to the supposed dangers of strong magnetic fields: Tesla spent his entire adult life around some of the strongest magnetic fields ever generated by man, and he died quietly in his sleep at the age of 87.

Re:Great Idea - Not there yet.

[amdpox]

Magnetic field != radiation. Even a fluctuating magnetic field isn't going to effect humans - I think the issue is more the EM interference a strong fluctuating field can bring about.

Tesla would be spinning in his grave...

[jolyonr]

assuming his body had a ferrite core and was wrapped in copper wire, or something...

Re:I've always wondered... here's why

[Anonymous Coward]

The house wiring doesn't create much field, electric or magnetic. You would have to be right next to the wire to use it.

Magnetic - The current going out the hot wire is exactly matched by that returning on the neutral. The fields due to the two currents cancel.

Electric - The hot wire has 120 volts on it and that would create an electric field but the neutral and ground wires are right next to it. That means the field, while not completely shielded, does not go very far.

OTOH: some appliances create pretty hefty fields. CRT TVs and monitors, motors and subwoofers come to mind. As long as you're willing to sit your calculator on an old CRT TV, you should be able to power it easily. ;-)

Re:Great Idea - Not there yet.

[Waffle Iron]

Magnetic field != radiation. Even a fluctuating magnetic field isn't going to effect humans

As Maxwell showed with his equations, fluctuating magnetic field == radiation, by definition. (And is always associated with a corresponding fluctuating electrical field.)

Your second statement is not always true either. For example, the fluctuating electromagnetic field inside a microwave oven would certainly affect humans.

Re:We're still playing catchup with Tesla!

[Waffle Iron]

How long ago did Tesla conceive of this, and we're still trying to keep up with the guy?

One little problem: Tesla thought that he would transmit megawatts of power wirelessly over transcontinental distances. The idea, as he conceived it, was and is completely unworkable. (Which helps to explain why he died penniless.)

How about a real comparison of efficiency?

[Anonymous Coward]

One thing that seems to be missing from the articles and discussion about this technology is a comparison to the current tech (in this case, extension cords/power strips). What is the loss that exists right now?

I'm no electrician, but as an attempt at a ballpark I looked up a voltage drop calculator at http://www.powerstream.com/Wire_Size.htm, plugged in 18AWG, 6 ft cord, 120V 1 phase power (an average extension cord from what I can determine) and got a 0.33% voltage drop. I don't know if voltage drop is a good indicator of total energy loss, but my rudimentary electrical knowledge suggests it might be.

Regardless, if that figure is even remotely accurate, it means we're comparing a 25% loss to a 0.33% loss, so the technology has a quite high efficiency cost compared to the current technology.

It might be more fair to compare the new system to a "wall wart" charger system, unfortunately I don't know what the typical gauge of wire is for that application, so here's a spread of guesses, with the power also adjusted to 6V DC and 1A (a more-or-less typical "charging" load)
30AWG 14.07% voltage drop
26AWG 5.6% voltage drop
22AWG 3.2% voltage drop

Obviously, the thinner the wire the more drop, but even if we're comparing 25% loss to 2.5% loss, that's an order of magnitude better than the assumption of comparing it to an extension cord.

Anyway, please elaborate on this if you're knowledgeable about it, I'm curious now.

Re:How about a real comparison of efficiency?

[aproposofwhat]

I'd guess that since it's AC, the efficiency is roughly in line with the square of the voltage drop (RMS power, from the dim and distant 1970's when I learnt physics).

So your 14.07% voltage drop works out at around 74% efficient - not far off the 75% claimed by Intel.

Broadcast power

[Digital End]

1: Scale that up to orbital range
2: Put a giant solar collector in orbit
3: Profit

Blue Sky

[DarthVain]

Somewhat pun intended, but to blue sky here a bit, wouldn't it be interesting if this type of technology was not limited by a few meters, but rather could be translated a much higher distance?

I am thinking of orbital solar collectors sending power earth side, to solve our power woes, with no impact.

Or even a step farther, set up solar power generating stations on the moon to the same effect. Now I guess this technology uses magnetic fields to transport the power, so perhaps earths natural field may muck that up, also delivering accurately to a very small area on earth might also be rather hard to do.

Anyway interesting food for thought, if only for science fiction.

Re:Blue Sky

[smellsofbikes]

Well, it isn't *limited* to a few meters, per se. The issue is, basically, that power radiated omnidirectionally drops off as the square of the distance -- and anything that's orbital has a LOT of distance.

One way of dealing with this is using directional beamed power. The proposed space elevator wants to power crawlers that go up the tether, and that's essentially the same problem. They're considering solving it by using lasers that beam power up to the crawlers from the ground. The reason for this is we know how to make directed energy transfer devices -- lasers -- that, while they still drop off as the square of the distance, what started off as a near-point-source at the laser might be a square meter or less at several hundreds of kilometers, rather than several hundred kilometers squared (as is the case with an omnidirectional emitter like a transformer.)

So it's no surprise that these things work, and yes, they could work from orbit, at what we'd consider extremely low efficiency. That's kind of notational, though, because if the power is just going to waste, from our point of view -- all the photons that don't hit earth -- catching any of them and sending any percent of that to the earth already means you're getting more energy than you had to start with. So in a way, efficiency doesn't matter: it's a question of return on investment.

But if we could come up with *safe*, directionally beamed power, then orbital power stations would start to look pretty attractive.

Of course, one possible contender for safe orbital power would be to use the filaments of solar elevators as conductors. (Although the voltages you'd have to use to conduct with reasonable efficiency over a transmission line 36,000 km long mean you'd have to use multiple elevators, with one being your high-voltage line and the other, many miles away, being your current return path, and you run into problems with trying to insulate the HV line from the earth itself.)

I'm going to wait on this technology until ...

[Skapare]

... they figure out to encrypt it so people can't steal my wireless power.