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Thread: Wireless power transfer

  1. #1 Wireless power transfer 
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    Which technology could permit long range (tens to hundreds of kilometers) wireless power transfer with very high efficiency and portable equipment? Do you think near field, ELF or VLF magnetic resonance created by metamaterial antennas or quantum coherence could be suitable for this?


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  3. #2  
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    Quote Originally Posted by Stanley514 View Post
    Which technology could permit long range (tens to hundreds of kilometers) wireless power transfer with very high efficiency and portable equipment? Do you think near field, ELF or VLF magnetic resonance created by metamaterial antennas or quantum coherence could be suitable for this?
    No. I think the whole idea is dangerous and impractical. Obviously near field makes no sense over the distance you are talking about (near field means < 1 wavelength), so it is far field i.e. radiative you have to think of. For this, it has to be microwave or shorter since diffraction of longer wavelengths make it impossible to contain any kind of beam within reasonable limits.

    And microwaves will fry people if anything goes wrong.


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    Quote Originally Posted by exchemist View Post
    Obviously near field makes no sense over the distance you are talking about (near field means < 1 wavelength), so it is far field
    There are attempts to create an electrically small antennas which are capable to radiate ELF and VLF waves very efficiently. ELF and VLF wavelength could reach hundreds of kilometers:
    Conventional antennas that are very small compared to the wavelength reflect most of the signal back to the source. A metamaterial antenna behaves as if it were much larger than its actual size, because its novel structure stores and re-radiates energy.
    Metamaterial antenna - Wikipedia
    Very low frequency communication systems (3 kHz–30 kHz) enable applications not feasible at higher frequencies. However, the highest radiation efficiency antennas require size at the scale of the wavelength (here, >1 km), making portable transmitters extremely challenging. Facilitating transmitters at the 10 cm scale, we demonstrate an ultra-low loss lithium niobate piezoelectric electric dipole driven at acoustic resonance that radiates with greater than 300x higher efficiency compared to the previous state of the art at a comparable electrical size.
    A high Q piezoelectric resonator as a portable VLF transmitter | Nature Communications
    The objective of this presentation is to show that use of novel metamaterials in the form of SuperParamagnetic Nanoparticles (SPN) as ELF/ VLF transmitters in the RB plasma can increase the efficiency of generation of ELF/VLF by more than 10-20 dB
    ELF/VLF Plasma Antenna based on Super-Paramagnetic Nanoparticles (SPN): Radiation Belt Remediation (RBR) Revisited - NASA/ADS (harvard.edu)

    1607.03420.pdf (arxiv.org)

    The analysis of resonant-type antennas based on the fundamental infinite wavelength supported by certain periodic structures is presented. Since the phase shift is zero for a unit-cell that supports an infinite wavelength, the physical size of the antenna can be arbitrary; the antenna's size is independent of the resonance phenomenon.
    Infinite Wavelength Resonant Antennas With Monopolar Radiation Pattern Based on Periodic Structures | IEEE Journals & Magazine | IEEE Xplore

    If someone will ever succeed to create portable and 90% efficient ELF or VHF antenna and receiver, then I could imagine two schemes: ether we could install one transmitter at the middle of a city and have thousands of users many kilometers around or have just two users which transfer power by means of resonance many kilometers from each other (in sparsely populated area). If both long-wavelengths (but portable) antennas (transmitter and receiver) are tuned in resonance to each other, there should be large overlap in their fields and perhaps high efficiency.
    Last edited by Stanley514; March 12th, 2021 at 04:58 PM.
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  5. #4  
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    Quote Originally Posted by Stanley514 View Post
    Quote Originally Posted by exchemist View Post
    Obviously near field makes no sense over the distance you are talking about (near field means < 1 wavelength), so it is far field
    There are attempts to create an electrically small antennas which are capable to radiate ELF and VLF waves very efficiently. ELF and VLF wavelength could reach hundreds of kilometers:
    Conventional antennas that are very small compared to the wavelength reflect most of the signal back to the source. A metamaterial antenna behaves as if it were much larger than its actual size, because its novel structure stores and re-radiates energy.
    Metamaterial antenna - Wikipedia
    Very low frequency communication systems (3 kHz–30 kHz) enable applications not feasible at higher frequencies. However, the highest radiation efficiency antennas require size at the scale of the wavelength (here, >1 km), making portable transmitters extremely challenging. Facilitating transmitters at the 10 cm scale, we demonstrate an ultra-low loss lithium niobate piezoelectric electric dipole driven at acoustic resonance that radiates with greater than 300x higher efficiency compared to the previous state of the art at a comparable electrical size.
    A high Q piezoelectric resonator as a portable VLF transmitter | Nature Communications
    The objective of this presentation is to show that use of novel metamaterials in the form of SuperParamagnetic Nanoparticles (SPN) as ELF/ VLF transmitters in the RB plasma can increase the efficiency of generation of ELF/VLF by more than 10-20 dB
    ELF/VLF Plasma Antenna based on Super-Paramagnetic Nanoparticles (SPN): Radiation Belt Remediation (RBR) Revisited - NASA/ADS (harvard.edu)

    1607.03420.pdf (arxiv.org)

    The analysis of resonant-type antennas based on the fundamental infinite wavelength supported by certain periodic structures is presented. Since the phase shift is zero for a unit-cell that supports an infinite wavelength, the physical size of the antenna can be arbitrary; the antenna's size is independent of the resonance phenomenon.
    Infinite Wavelength Resonant Antennas With Monopolar Radiation Pattern Based on Periodic Structures | IEEE Journals & Magazine | IEEE Xplore

    If someone will ever succeed to create portable and 90% efficient ELF or VHF antenna and receiver, then I could imagine two schemes: ether we could install one transmitter at the middle of a city and have thousands of users many kilometers around or have just two users which transfer power by means of resonance many kilometers from each other (in sparsely populated area). If both long-wavelengths (but portable) antennas (transmitter and receiver) are tuned in resonance to each other, there should be large overlap in their fields and perhaps high efficiency.
    But energy conversion of VLF antennae is appallingly inefficient isn't it?
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    Quote Originally Posted by exchemist View Post
    But energy conversion of VLF antennae is appallingly inefficient isn't it?
    Why is it unavoidable? Is there any fundamental laws which govern it?
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  7. #6  
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    Quote Originally Posted by Stanley514 View Post
    Quote Originally Posted by exchemist View Post
    But energy conversion of VLF antennae is appallingly inefficient isn't it?
    Why is it unavoidable? Is there any fundamental laws which govern it?
    Yes I think there are, not least the inability to build an antenna of the necessary size to be efficient. But I' not a radio engineer, so I'm just going on what I have read. Efficencies seem often to be as low as 10% and never seem to exceed 50% for VLF.

    But why don't you research it and let us know?
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    Could be quantum entanglement ever used to transfer energy?
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  9. #8  
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    Quote Originally Posted by Stanley514 View Post
    Could be quantum entanglement ever used to transfer energy?
    No.
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    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by Stanley514 View Post
    Could be quantum entanglement ever used to transfer energy?
    No.
    Why?
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  11. #10  
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    Quote Originally Posted by Stanley514 View Post
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by Stanley514 View Post
    Could be quantum entanglement ever used to transfer energy?
    No.
    Why?
    No-communication theorem
    There are no paradoxes in relativity, just people's misunderstandings of it.
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    Quote Originally Posted by KJW View Post
    Does it mean that energy transfer is principally impossible without data transfer? Usually energy and information are regarded as quite different entities in physics. Could it be possible that we may transfer energy without data transfer at quantum level? Let say it will look like some kind of "information noise" which carries no useful data. What do you think about this?:
    Quantum energy teleportation - Wikipedia
    And this:
    It was recently predicted that, in a composite quantum system exposed to dephasing noise, quantum coherence in a transversal reference basis can stay protected for an indefinite time.
    Phys. Rev. Lett. 117, 160402 (2016) - Observation of Time-Invariant Coherence in a Nuclear Magnetic Resonance Quantum Simulator (aps.org)

    We have a lot of power lines which stretch for millions of kilometers. Could they be turned to an efficient VLF transmitter or be optimized for near field generation? Also, what about using Schumann resonances - Wikipedia? If we have a one circuit in resonance with Earth electric field and another circuit a hundred of kilometers apart which is also tuned to Earth resonance, doesn't it mean we will have a common resonance between this two and efficient power transfer?

    Could we use for power transfer massless electrons which are capable to jump through barriers of any width?
    the Dirac electrons found in graphene can tunnel through energy barriers regardless of their width and energy height
    The secrets of tunneling through energy barriers (phys.org)

    Could we take two pieces of graphene separated by a large distance and make electrons tunnel trough the air?
    Last edited by Stanley514; March 22nd, 2021 at 05:13 PM.
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    Quote Originally Posted by Stanley514 View Post
    Quote Originally Posted by exchemist View Post
    But energy conversion of VLF antennae is appallingly inefficient isn't it?
    Why is it unavoidable? Is there any fundamental laws which govern it?
    Tesla tried this decades ago and failed. No one has picked up the torch since because electricity is lethal.
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    Quote Originally Posted by Quantated View Post
    No one has picked up the torch since...
    That would be false.
    "[Dywyddyr] makes a grumpy bastard like me seem like a happy go lucky scamp" - PhDemon
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    Quote Originally Posted by Dywyddyr View Post
    Quote Originally Posted by Quantated View Post
    No one has picked up the torch since...
    That would be false.
    Torches that shed no light are of no use
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    Quote Originally Posted by Quantated View Post
    Quote Originally Posted by Dywyddyr View Post
    Quote Originally Posted by Quantated View Post
    No one has picked up the torch since...
    That would be false.
    Torches that shed no light are of no use
    Thats a rather nosensical answer to the reply you were given.
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