Free Power!
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Joined: Sep 2005
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From: Chicago. (The less-murder part.)
Free Power!
Booyeah!
Several years ago, somebody posted in a thread that they felt it should be possible to run a car on "free" energy.
I can't remember if the energy in question was supposed to have come from cosmic background radiation or what (can't find the thread any longer) but I suggested that they power it by harnessing all of the "free" RF that's floating around the populated parts of the earth, then did some math and posited a rather tongue-in-cheek solution that involved attaching an antenna to the vehicle consisting of two flat plates, each one several square kilometers in size, and then ensuring that his daily commute consisted entirely of driving down roads which happen to have high-power broadcast transmitters situated along them at a spacing of one every half-mile or so.
Turns out that some folks at Georgia Tech were apparently reading the thread, because they took me seriously. Granted, they're excited about being able to generate a whole milliwatt:
Several years ago, somebody posted in a thread that they felt it should be possible to run a car on "free" energy.
I can't remember if the energy in question was supposed to have come from cosmic background radiation or what (can't find the thread any longer) but I suggested that they power it by harnessing all of the "free" RF that's floating around the populated parts of the earth, then did some math and posited a rather tongue-in-cheek solution that involved attaching an antenna to the vehicle consisting of two flat plates, each one several square kilometers in size, and then ensuring that his daily commute consisted entirely of driving down roads which happen to have high-power broadcast transmitters situated along them at a spacing of one every half-mile or so.
Turns out that some folks at Georgia Tech were apparently reading the thread, because they took me seriously. Granted, they're excited about being able to generate a whole milliwatt:
Researchers at Georgia Tech are tapping emissions from a TV station located half a kilometer from their lab to power a wireless temperature sensor.
Manos Tentzeris, a professor in the Georgia Tech School of Electrical and Computer Engineering leading the research said, “There is a large amount of electromagnetic energy all around us, but nobody has been able to tap into it. We are using an ultra-wideband antenna that lets us exploit a variety of signals in different frequency ranges, giving us greatly increased power-gathering capability.”
The self-powered wireless sensors are created using ink-jet printers and a special ink containing nanoparticles of silver and/or other material. The researchers have been able to combine sensors, antennas and energy-scavenging capabilities on paper or flexible polymers. The resulting sensors can be used for chemical, biological, heat and stress testing for defense and industry. The devices are able to use RF sources ranging from 100 MHz to 15 GHz or higher.
A Georgia Tech Research News article said scavenging experiments using TV bands have already yielded power amounting to hundreds of microwatts. Multi-band systems are expected to generate one milliwatt or more, enough to operate many small electronic devices, including a variety of sensors and microprocessors. Devices requiring 50 mW or more should be able to be powered by adding super-capacitors and using cycled operation.
The Georgia Tech team is also looking at alternative power for the sensors—most likely solar—with the scavenged RF power used at night. Can you imagine a situation where keeping those high power TV transmitters on the air could become a national security issue, not because of the programming but because they are powering an array of sensors used in critical applications?
Source: http://www.tvtechnology.com/article/122502
Manos Tentzeris, a professor in the Georgia Tech School of Electrical and Computer Engineering leading the research said, “There is a large amount of electromagnetic energy all around us, but nobody has been able to tap into it. We are using an ultra-wideband antenna that lets us exploit a variety of signals in different frequency ranges, giving us greatly increased power-gathering capability.”
The self-powered wireless sensors are created using ink-jet printers and a special ink containing nanoparticles of silver and/or other material. The researchers have been able to combine sensors, antennas and energy-scavenging capabilities on paper or flexible polymers. The resulting sensors can be used for chemical, biological, heat and stress testing for defense and industry. The devices are able to use RF sources ranging from 100 MHz to 15 GHz or higher.
A Georgia Tech Research News article said scavenging experiments using TV bands have already yielded power amounting to hundreds of microwatts. Multi-band systems are expected to generate one milliwatt or more, enough to operate many small electronic devices, including a variety of sensors and microprocessors. Devices requiring 50 mW or more should be able to be powered by adding super-capacitors and using cycled operation.
The Georgia Tech team is also looking at alternative power for the sensors—most likely solar—with the scavenged RF power used at night. Can you imagine a situation where keeping those high power TV transmitters on the air could become a national security issue, not because of the programming but because they are powering an array of sensors used in critical applications?
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What are you going to do with a couple of microwatts? This is as bad as GM or whoever that was investing $12 billion in a no-plugin charging mat for items where there is a convenient plug-in 8.7" away from the charging mat.
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Thread Starter
Joined: Sep 2005
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From: Chicago. (The less-murder part.)
Well, you could power a wireless temperature sensor. 
On re-reading, my first post here didn't come off sounding as frivolous as I'd intended. The practical applications for such a technology as this are indeed... finite. Sure, you could easily put enough RF energy into the air to be able to power useful devices, but unfortunately, this would have the side-effect of killing just about every living thing on earth. (And, of course, you'd have to generate said power in the first place.)
It's interesting how, with the right wording coming from a seemingly reputable source, even the most trivial of things can be made to sound like a marvelous breakthrough in technology.
On re-reading, my first post here didn't come off sounding as frivolous as I'd intended. The practical applications for such a technology as this are indeed... finite. Sure, you could easily put enough RF energy into the air to be able to power useful devices, but unfortunately, this would have the side-effect of killing just about every living thing on earth. (And, of course, you'd have to generate said power in the first place.)
It's interesting how, with the right wording coming from a seemingly reputable source, even the most trivial of things can be made to sound like a marvelous breakthrough in technology.
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Find me a cheap and efficient way to steal electricity from the air from the high voltage transmission lines near my house. Surely the aura from the lines could be remotely harnessed in some useful fashion.
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Joined: Jun 2005
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From: Fake Virginia
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Joined: Oct 2007
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From: The coal ridden hills of Pennsylvania
Go stand under those high voltage lines after dark while holding a florescent bulb in your hand and tell me what happens.
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Joined: Oct 2007
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From: The coal ridden hills of Pennsylvania
They key is to harness it in a way that nobody will know about. For instance, I live near a river. I'd love to have a hydro-electric generator that goes to my house only. Even if it only made enough power to run stuff like my refrigerator and my underground dog fence, I'd still benefit.
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They key is to harness it in a way that nobody will know about. For instance, I live near a river. I'd love to have a hydro-electric generator that goes to my house only. Even if it only made enough power to run stuff like my refrigerator and my underground dog fence, I'd still benefit.
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From: Chicago. (The less-murder part.)
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It should do it around lines as well. You can hear and feel the power in the air, pretty weird feeling. Just not sure how or if you could capture the power without making an arc to the line. Which if it lights up a bulb, then I guess you could capture it in some sort of storage the same way to be used.
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Thread Starter
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From: Chicago. (The less-murder part.)
It's all about magnitude.
To light up a florescent bulb or power a tiny little temperature sensor requires very little power.
To do anything that most people would consider "useful" (eg: run a car, charge a cell phone, etc) takes a great deal more power. There just isn't that much energy being "lost" out of power lines.
To light up a florescent bulb or power a tiny little temperature sensor requires very little power.
To do anything that most people would consider "useful" (eg: run a car, charge a cell phone, etc) takes a great deal more power. There just isn't that much energy being "lost" out of power lines.
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