Intel Claims an Advance In Wireless Power 327
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.
What a waste of energy (Score:4, Insightful)
Re:What a waste of energy (Score:5, Funny)
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 (Score:4, Funny)
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.
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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 (Score:5, Interesting)
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 [ecost.com]
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 (Score:4, Informative)
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 (Score:5, Insightful)
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 (Score:5, Informative)
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.
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" 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 wo
Re:What a waste of energy (Score:4, Informative)
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:
http://en.wikipedia.org/wiki/Nikola_Tesla [wikipedia.org]
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 (Score:5, Interesting)
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.
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Re:What a waste of energy (Score:5, Interesting)
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 (Score:5, Informative)
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 [studio360.org]
Re:What a waste of energy (Score:5, Insightful)
Or maybe it was just considered a bad idea, and I think it's now as well.
Re:What a waste of energy (Score:5, Insightful)
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.
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His name was not Julius [wikipedia.org].
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Sure it was, he and Orange Julian used to hang out all the time with corporal Saunders.
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It's kind of hard to insert an ad into your electricity. The GP speaketh correctly... he *was* shot down on his idea because it's not possible to meter/bill for usage.
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That mouse is just how RFID, or the touchless payment cards work. However, the technology presented here is talking about a totally different mechanism.
FTA: "Induction is already used to recharge electric toothbrushes, but that approach is limited by the need for the toothbrush to be placed in the base station."
(And electric toothbrushes are already here for decade?)
If you try anything like transmitting 120W (60W / 50% efficiency) in that old way, mostly will end up with a mini-induction cooker [wikipedia.org]
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Umm no. The mouse uses no batteries and also uses radio frequency to transmit the mouse tracking. It uses magnetic induction for power.
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And rfid doesn't get its power thru coils and magnetic fields? How does it work?
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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"
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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.
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Sure you can - meet Mr. Dremel Tool [wikipedia.org]. 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.
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Charging pads? I mean, how lazy are people to simply plug in their iPod?
You know, maybe instead of some "charging pad" we just need a universal adapter, something rectangular, maybe, that could be used to charge things. Maybe call it Universal Systems Battery connector or something....
Seriously, wire connector == ~100% efficiency for power transfer. This world does need a few hundred more coal power plants spewing mercury, uranium and other crap all over us so we don't have to plug in our 20th generation iP
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see anonymous comment above with this link: http://www.afrotechmods.com/cheap/arnoldpad/arnoldpad.htm [afrotechmods.com]
of course, skip the ahhnold humor.
At about 1/4 of an inch away from a pad (which can charge batteries OR enable a device which sits on the pad to be used without any batteries whatsoever - this is what the mouse I linked is), the efficiency is a lot better. Intel's extending the range.
It is a completely 100% universal adapter, and even works with things that are not rechargable and will give them some electr
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okay so. Let's try this again, I will not insult you this time however as I apologize for being a bit over the top.
This intel system, nor the system in the mouse I referenced, are not necessarily degaussing fields. It would depend on the wavelengths and charges used. Just because it transmits power doesn't imply degaussing.
The systems already in place will indeed charge any existing battery of any device that is capable of holding a charge. see http://www.afrotechmods.com/cheap/arnoldpad/arnoldpad.htm [afrotechmods.com] if y
Re:What a waste of energy (Score:4, Insightful)
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 (Score:5, Funny)
Re: (Score:2, Flamebait)
Parent should be funny, not interesting - it's an April Fool's product.
Re:What a waste of energy (Score:5, Funny)
Re: (Score:2, Informative)
Re:What a waste of energy (Score:4, Insightful)
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 (Score:5, Interesting)
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: (Score:3, Insightful)
Re: (Score:2, Funny)
You're new here^h^h^h^h to statistics, aren't you?
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No, he later said, "If magnetic fields caused cancer, linemen would die of lukemia[sic] right and left."
Now, there are studies that do not favor his point of view... a quick google gives me the result that linemen are actually 2.5 times more likely to get leukemia.
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Re:What a waste of energy (Score:5, Insightful)
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.
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I realise it's just anecdotal. Also, there isn't much cancer in my family.
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That 60Hz is also a good B-flat in case you need to tune a musical instrument.
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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.
Re: (Score:3, Informative)
How Acoustic Guitars Work [howstuffworks.com] shows that 120 Hz is in-between B and A#, and 60 Hz is exactly one octave lower than 120 Hz.
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A few years back the power company bought some right away to string some high tension lines through this farmers property. He had a shed that he used as a work stop and was lit by fluorescent lights. After the power company put up the lines at night the tubes would glow from the magnetic field. I guess it depended on the load on the lines but sometimes they would by dim and some times bright enough to work by at night. Damn eerie as hell is what is was.
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Not to the same extent but it has a high voltage power transformer for the backlight.
Re:What a waste of energy (Score:5, Interesting)
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.
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I think your estimate of how costly it is to remove the extra heat generated is too high.
I entirely agree about wired always-on devices, though. I have a ton of AC-to-DC converters and power supplies that are terribly inefficient and a host of devices (including chargers) that are always running in standby mode.
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In many parts of the country, you only need to remove the heat for 3 or 4 months out of the year... waste heat isn't wasted in the winter.
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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.
Pick your battles (Score:2)
Worrying about the energy waste from wall warts and PC's is like being concerned about the drip in your ceiling while there is a dam break upstream. Home heating and transportation energy use is twice the magnitude of consumption (1kW vs. 4-500kW or more) and a very small reduction there is a much better idea.
The convenience of wireless charging outweighs the (trivial) energy losses is most applications.
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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%.
WTF kind of math is that. Say I got a gadget fed on line power with 100% efficiency at 100W. Now we use this, I need (100W/75% =) 133W of the original current. Now all of that is converted to heat, the question is just if we get something useful out of it first. You think my 200W (load), 85% efficiency PSU makes the machine give off 200W*15% = 30W heat? Think again, the machine gives off 200W heat total. So if you claim AC efficiency is 20%, well we consume 100W/20% = 500W on line power or 133W/20% = 665W o
Re:What a waste of energy (Score:5, Interesting)
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.
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I've always wondered... (Score:4, Interesting)
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.
Re: (Score:2)
IANAEE, but you may wish to wear your watch outside, where it is not surrounded by electrical wires.
Re:I've always wondered... here's why (Score:5, Interesting)
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. ;-)
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There an easier solution. Why don't they use electromagnetic radiation to power calculators? just a little glass plate, let's call it electromagnetic cell, no, "light cell", that's easier, we'll just paint them black to absorbe visible light.
They would even work outside, in the sun.. oh, wait!
alternative (Score:5, Insightful)
Re: (Score:3, Insightful)
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: (Score:3, Funny)
Now, that's just crazy talk.
Re:alternative (Score:4, Interesting)
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.
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And what voltage do you recommend for your single power socket? 12V? 6V? 5V? 3.3V? maybe 1.5 or 0.8V? Perhaps just a simple 24 and let everybody downconvert?
Most mfrs want to minimize the need for conversion in their devices. This would get you from AC to DC, but would not quite buy you a universal solution.
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But see, that would put an end to the extremely profitable portable device accessories market where chargers that cost $0.30 to make are sold for $30.00. Can't have that, now can we!?
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Radical tech solutions for....providing low-voltage DC to a gadget? Is there *really* some need for "outside the box" thinking for that?
I knew it (Score:5, Funny)
Great Idea - Not there yet. (Score:2)
While I'm not well-versed in the possible dangers of all this additional radiation, clearly we can't argue that it's anywhere near mainstream yet.
In an age where we are increasingly becoming aware of just how fragile our fossil fuel-based energy supply is, even small-scale uses of this technology would need to see a significant increase in efficiency. Losing a quarter of your energy in the final step (nevermind whatever the endpoint device wastes as heat or whatnot), is simply unacceptable.
I say give it ano
Re:Great Idea - Not there yet. (Score:4, Insightful)
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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.
This is new? (Score:4, Insightful)
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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!
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IMO, not at all. The setup looks exactly like something Tesla built almost 100 years ago. Even Tesla's classic design style of the coils is used. In what little of Tesla's documentation I've seen, it would appear he beat the 75% barrier at greater distances long ago. This is one old idea that won't die and it shouldn't!
A more practical laptop solution would place the primary coil directly below the laptop, such as under a (physical) desktop. These power units would cost no more than a normal adapter -- a co
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When I was a kid I had a book written ~ 1910 called 'The Boy Electrician' that had a something very similar included as a project.
It also had an x-ray machine with complete instructions. The good old days!
http://www.lindsaybks.com/bks/boyelec/index.html [lindsaybks.com]
Good luck shrinking the coils (Score:2)
My understanding of the physics of linked resonant coils is that the coupling efficiency at a given range (once you're farther away than a few times the coil diameter) is proportional to the coil diameter cubed. So if you halve the ring size, you drop the range by a factor of 8.
Wire the walls then (Score:2)
Then let's just scale the loops with the building where it is meant to be used. Wire the walls.
Ok, Slashdot team goal. (Score:5, Funny)
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.
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There hasn't yet been a single joke involving either a member of an ethnicity or a profession and their ability to change a wireless lightbulb. I consider that progress.
Come to think of it, how many Croatian scientists does it take to change a wireless lightbulb?
and the day after the tech goes live (Score:5, Insightful)
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.
Tesla did this a long time ago. (Score:5, Interesting)
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.
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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.
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And I know a smoker who's 88 yrs old. No emphysema or other problems.
Still, I understand your point. Speaking as a amateur radio operator, I only fear high wattage, focused output, and ionizing radiation. If the PEP is fairly high, it gets veeeery dangerous.
I once saw a EME rig that did 200 kW PEP. Scary stuff, considering that's lethal to damn near everything (except Deinococcus radiodurans).
Re:Tesla did this a long time ago - so did I (Score:2)
This was before "star wars" and it was dark, so the sight of a couple of people waving 4-foot fluorescent tubes about was quite novel.
Im sure i speak on behalf of all of us (Score:2)
Tesla would be spinning in his grave... (Score:5, Funny)
assuming his body had a ferrite core and was wrapped in copper wire, or something...
Star Trek Wireless Power (Score:2)
A bolt of plasma shooting across engineering between the M-5 multitronic unit and the engines.
Sure it's a little hazardous to red shirts, but that's the price of progress.
Parallel or Perpendicular? (Score:2)
How about a real comparison of efficiency? (Score:2, Interesting)
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
Re:How about a real comparison of efficiency? (Score:4, Interesting)
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.
Those dang laws of physics keep interfering (Score:2)
There's these things called the basic laws of physics which make this idea a dead end.
Magnetic fields go between two poles and not much further afield. That makes the far field go down as the cube of the distance. Basically insurmountable gotcha.
Broadcast power (Score:3, Interesting)
2: Put a giant solar collector in orbit
3: Profit
Blue Sky (Score:3, Interesting)
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 (Score:4, Interesting)
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.)
OMG thinkofthecarbonfootprint (Score:2)
I'm proposing a new tag "thinkofthecarbonfootprint". For those of you who are about such things. I think it stands to reason that recharging via this method would increase existing power consumption (and therefore co2) by 25%.
Yeah, it'd be fun ans great, but who is willing to sacrifice the planet for the plug-in inconvenience?
(FTR: I am not an anthropogenic global warming believer)
I'm going to wait on this technology until ... (Score:4, Funny)
... they figure out to encrypt it so people can't steal my wireless power.
Re:We're still playing catchup with Tesla! (Score:4, Interesting)
Re: (Score:3, Informative)
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.)
Re: (Score:2)
And how exactly is it impossible to transmit megawatts of power wirelessly over transcontinental distances? We can already do it via microwaves, so of course there are probably other ways to do it that we just haven't figured out yet.
But Tesla wasn't using microwaves, which only work line-of-sight, and which hadn't been invented yet. Tesla wanted to somehow use the ionosphere and/or ground currents to make the energy follow the curvature of the earth. This is a totally different concept, and it cannot work.
BTW, we can theoretically transmit megawatts of microwaves over long distances. Nobody has demonstrated such a system, which would only make sense for spece-based solar power.
Re: (Score:2)