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Wireless Electricity Transmission

  1. Jun 13, 2017 #1
    Folks, I am still thinking of the possible approach to solving a problem of having to run poles and power lines to transmit electricity from one point to the other. Can there be a way it could be done in that we can convert electric current into electro-magnetic waves that can be transmitted through space and then converted back to electriccurrent at the receiving side?. My idea is that wiring is only done inside the houses which get power from the outdoor receiver with the ability to convert EM signals into electric current.
     
  2. jcsd
  3. Jun 13, 2017 #2

    anorlunda

    Staff: Mentor

    :welcome:

    Lots of people have tried to invent that, but nothing practical has appeared yet.

    Microwaves beamed from space to Earth has been suggested. But there is little difference between microwave power and a death ray. Think of the Bond movie Diamonds Are Forever.
     
  4. Jun 13, 2017 #3

    Drakkith

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    Staff: Mentor

    Absolutely. It's just extremely inefficient since much of the EM radiation is lost as it spreads out after transmission. There's also the problem that it's very difficult to send a signal wirelessly if the frequency is extremely low. At 60 Hz, sending and receiving a signal efficiently requires an absolutely enormous antenna on both sides. These antenna would need to be miles long, far bigger than the houses they'd be supplying. Increasing the frequency would help, but then you run into other issues.

    Also, the amount of power consumed by the average household is very large. Putting enough EM radiation into the air to supply this power would be extremely hazardous and would cook every bird in the area of a transmitter. And probably every person too.
     
  5. Jun 18, 2017 #4
    You sometimes see claims for 'alternative energy' devices that inductively 'leech' stray power from nearby power-lines. If such lines are 'just passing', a serious forum's replies will warn that the 'utility' may consider this 'unauthorised abstraction' aka 'theft' and lawyer-up...

    IIRC, if you 'Faraday Cage' your property and earth {'ground'} that, the utility won't complain about their few Watts lost...

    FWIW, it's easy enough, given a good antenna, to tune an 'LC' circuit to a powerful local transmitter, rectify the tiny, tiny output and use that to drive a micro-power amplifier for a receiver tuned to a *different* transmitter. Classic 'Science Fair' stuff. Tesla proposed a mega-version, but ran into the problem of billing customers plus spamming a wide band of RF spectrum...

    Um, you *can* transmit serious power wirelessly; an 'Induction Hob' does it well. IIRC, a tracking antenna can drive a mini-drone with micro-waves out to several hundred metres. And, IIRC, some EMP and pulsed-fusion devices use a 'discharge' riding a plasma path formed by a precursor laser zap etc. Shades of ST's 'plasma ducts', but 'vacuum' really can carry a power density that would vaporise superconducting cabling. Think 'Tame Lightning'...
     
  6. Jun 18, 2017 #5

    Drakkith

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    Staff: Mentor

    I wouldn't test this idea. A household pulls more than a few watts and over time this adds up to a substantial amount of power.

    Perhaps, but none of these are suitable for electrical power delivery to residential or commercial facilities, which is what the OP was asking about.
     
  7. Jun 19, 2017 #6
    Oh yes! I get it. The cooking up of things in the surrounding has also always been my set back about this Idea on top of the waves colliding with communication waves to cause other issues in that regard may not be sexy at all!!!
     
  8. Jun 23, 2017 #7
    Nik_2213 said: IIRC, if you 'Faraday Cage' your property and earth {'ground'} that, the utility won't complain about their few Watts lost...
    "I wouldn't test this idea. A household pulls more than a few watts and over time this adds up to a substantial amount of power."

    Sorry, I meant the legal side-- They'll not complain provided you're *just* earthing the cage, and do not make any use of the small power draw in any way. After all, unwanted induction from their passing power lines could be construed as 'legal nuisance', like a sludge-pit's persistent stink...

    IIRC, back when 'Solar Power Satellites' were a fashionable notion, their planned frequency, beam-width and base-stations' 'Rectenna' sizing were a trade-off between cost-effectiveness and zapping birds, balloonists etc, with a wary eye on the dangers of having SPS tracking systems hijacked...
     
  9. Jun 23, 2017 #8

    Drakkith

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    Staff: Mentor


    If you highlight text inside of someone's post, you can quote that highlighted portion instead of typing it out manually.

    Oh, I thought you were saying to directly use the cage to suck power from the lines. Now that I re-read your post I see that the first part was essentially saying not to do this. My mistake.
     
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