Wireless Power Transmission

[Sato]

A friend of mine was telling me about his research and that with it a larger version of his prototype could be built to power electrical devices including cars and trains via wireless power transmission and efficaciously. The transmission system has 98% quantum efficiency (not sure what that means, but it sounds good).

 

To all who've studied optics or more so applied optics/photonics, is this feasible or an exaggeration of the capabilities of wireless power transmission?

[EdEarl]

Quantum efficiency is the ratio of electrons produced per photon. The 98% figure is possible, in fact it can be higher than 100% when the photon energy is high enough to create two electrons.

 

Air absorbs some photons, which results in ionization of air molecules. Such ionization reduces transmission efficiency and might start a fire.

 

Sunlight falling on a square meter is about 1 horsepower; thus, to run a < 25 HP car would require light about 25 times as intense as sunlight. Such a high intensity light beam seems rather dangerous to me. It may be possible, but mag lev seems more practical.

Edited May 12, 2013 by EdEarl

[DevilSolution]

Its not a photo-voltaic process, its electro-magnetic. Magnetic pads would work in a similar fashion to transformers.

 

http://www.theengineer.co.uk/automotive/the-engineer-qa-wireless-electric-vehicle-charging/1015639.article

[Enthalpy]

"Wireless power transmission" uses to mean by magnetic coupling, which

- Works at short distance only (but possibly at traffic lights, with loops embedded in the lane)

- Has a limited efficiency, often <70%, but might be improved. Though, 98% would surprise me.

 

"Quantum efficiency" is normally used in opto devices and would be useless for magnetic coupling. Opto transmitter have a QE lower than 98%; opto receiver can have 98 QE, but the output electrons are available under a lower voltage than the photon energy, which means an energy efficiency seriously lower.

[Sato]

"Wireless power transmission" uses to mean by magnetic coupling, which

- Works at short distance only (but possibly at traffic lights, with loops embedded in the lane)

- Has a limited efficiency, often <70%, but might be improved. Though, 98% would surprise me.

 

"Quantum efficiency" is normally used in opto devices and would be useless for magnetic coupling. Opto transmitter have a QE lower than 98%; opto receiver can have 98 QE, but the output electrons are available under a lower voltage than the photon energy, which means an energy efficiency seriously lower.

 

I'm not sure if you're referring to this, but the electrical efficiency is 90%, and it works at any distance according to him (and others who were at a demo he did), unless there's an iron barrier between them. Does that seem right, and enough such that long distance wireless vehicle powering is feasible with this?

 

 

Quantum efficiency is the ratio of electrons produced per photon. The 98% figure is possible, in fact it can be higher than 100% when the photon energy is high enough to create two electrons.

 

Air absorbs some photons, which results in ionization of air molecules. Such ionization reduces transmission efficiency and might start a fire.

 

Sunlight falling on a square meter is about 1 horsepower; thus, to run a < 25 HP car would require light about 25 times as intense as sunlight. Such a high intensity light beam seems rather dangerous to me. It may be possible, but mag lev seems more practical.

It is non-ionizing radiation, if that applies to this, and made a joke that it could be used as a directed energy weapon before.

Edited May 18, 2013 by Sato

[Enthalpy]

Your latest quote has gone wrongly, as that message was from EdEarl.

 

90% power efficiency through magnetic coupling must be possible. Present-day figures are more like 70% for optimized inductive coupling, without a common iron core, but with resonance (and 99.9% for a big transformer, but that's not the same game).

 

What I doubt very seriously is that coupling can remain efficient if the distance exceeds widely one coil diameter. Then it would be a different process, if it really works. Microwaves can make narrow beams over some distance, but their production is at best 70% efficient and their rectification about as bad.

 

Unless reading and seeing more about the demo, I consider it a joke.

[EdEarl]

Your latest quote has gone wrongly, as that message was from EdEarl.

Please explain my error?

[Sato]

Your latest quote has gone wrongly, as that message was from EdEarl.

 

90% power efficiency through magnetic coupling must be possible. Present-day figures are more like 70% for optimized inductive coupling, without a common iron core, but with resonance (and 99.9% for a big transformer, but that's not the same game).

 

What I doubt very seriously is that coupling can remain efficient if the distance exceeds widely one coil diameter. Then it would be a different process, if it really works. Microwaves can make narrow beams over some distance, but their production is at best 70% efficient and their rectification about as bad.

 

Unless reading and seeing more about the demo, I consider it a joke.

 

The process is photovoltaic.

 

Also, here is an excerpt from a description he wrote up:

 

Using an interdisciplinary approach, lasers of various wavelengths were collimated and directed towards a bi-axial Microelectromechanical scanner to allow for dynamic spatial modulation in any direction. This methodology permits electromagnetic radiation to be beamed exclusively at the target in real-time, increasing transmission efficiency by orders of magnitude. Proprietary tracking algorithms utilizing GPS triangulation and Ad-Hoc/WWAN network feedback were developed in order to accurately locate the photovoltaic receiver in 3-dimensional space.

 

That's all that I'm able to provide about it; from that, should I take it that he was most likely just exaggerating?

 

Please explain my error?

 

You did not make an error, I did with my quoting. The author was shown as enthalpy, while it should have been EdEarl.

[Enthalpy]

Sending power by light in an accurate direction is a means to transfer power.

• 98% quantum efficiency is normal at the receiver.
• The receivers's power efficiency is less good but can be reasonable if light is monochromatic well tuned to the material's wide bandgap. Imagine 2eV gap and photons, and 1.3V output voltage, this term is 65%.
• If made properly, targeting can be very efficient over a reasonable distance and by good weather.
• Light sources are bad. Laser diodes less so. Forget the 90%.
• You won't transmit by light the real-time power needed by a car, will you?

This transmission is NOT what you suggested by "unless iron barrier". Are you really trying to understand a friend's work? Or do you want us to give ideas for your own work instead, and try to conceal this goal?

[Sato]

Sending power by light in an accurate direction is a means to transfer power.

• 98% quantum efficiency is normal at the receiver.
• The receivers's power efficiency is less good but can be reasonable if light is monochromatic well tuned to the material's wide bandgap. Imagine 2eV gap and photons, and 1.3V output voltage, this term is 65%.
• If made properly, targeting can be very efficient over a reasonable distance and by good weather.
• Light sources are bad. Laser diodes less so. Forget the 90%.
• You won't transmit by light the real-time power needed by a car, will you?

This transmission is NOT what you suggested by "unless iron barrier". Are you really trying to understand a friend's work? Or do you want us to give ideas for your own work instead, and try to conceal this goal?

 

He said that it could go anywhere unless the receiver was blocked by an Iron barrier, or at least I think I recall that. And no, I'm a layman and that is definitely not my intention; I am trying to understand how his project works and if it's stated implications are feasible.

 

There is one part he explicitly told me not to tell anybody about as the patent is pending and organizations may try to scrutinize it, but it seems to relate to one of your bullets so I will censor the details:

 

Censor censor based semi-conductor receiver perfectly matches up with the bandgap energy of the transmitter to achieve a 1:1 resonance

 

I think that makes it such that less energy is lost when the light is at the receiver.

[EdEarl]

There are patents for all kinds of things that do not work, including perpetual motion machines. Moreover, in a few cases, the government has patented something after it was already patented by someone...patent theft. Additionally, some countries do not honor US patents, but anyone can order a copy. Thus, patents can be stolen by a foreigner who lives in such a country.

 

One of the biggest problems is that patent owners only have 13 years plus one 13 year renewal, and corporations would rather not pay for a patent and wait till it expires. At which time, anyone can make and sell things previously protected by patent.

[Sato]

There are patents for all kinds of things that do not work, including perpetual motion machines. Moreover, in a few cases, the government has patented something after it was already patented by someone...patent theft. Additionally, some countries do not honor US patents, but anyone can order a copy. Thus, patents can be stolen by a foreigner who lives in such a country.

 

One of the biggest problems is that patent owners only have 13 years plus one 13 year renewal, and corporations would rather not pay for a patent and wait till it expires. At which time, anyone can make and sell things previously protected by patent.

 

Well, I believe that the device is real as I know people who saw a working demo, and he's backed by a big research university and government agency (sorry for the ambiguity, I just don't think he'd be fond of me posting such details on a public forum), but not exactly sure about that larger aspect with the car and train powering. Can someone re-patent something after the 26 years?

 

Also, just curious, what do you do EdEarl?