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What is the Future of Wireless Power?

Posted by CmdrTaco on from the this-is-gonna-burn-my-crotch-isn't-it dept.

mfbatzap writes "According to Firdooze, we have seen various devices that can free ourselves from wires at CES 2008. The manufactures, Wildcharge, Powercast and Fulton Innovation, came out with two different methods of transmitting power from source to the devices. Wildcharge and Fulton banked on magnetic coupling while Powercast decided to go with RF (Radio Frequency). So which technology will eventually prevail to be the future of wireless power? Or will the technological setbacks from transferring power wirelessly make it unrealistic to accomplish a wire-free world?"

5 of 178 comments (clear)

  1. is there a way by JeanBaptiste · · Score: 3, Interesting

    to transfer power wirelessly without cooking whatever happens to pass inbetween the sender and receiver?

    1. Re:is there a way by Otto · · Score: 5, Interesting

      From what I understand, it depends on the frequency. For instance, a microwave oven operates at whatever frequency best excites a water molecule, which leads to cooking by making the water in everything hot. That is incorrect, but you're forgiven because it is a common misconception that's even in a few encyclopedia's and such.

      Microwaves work by producing an alternative electric field (using non-ionizing microwave radiation) that acts on molecules which have electric dipoles. Water is one of those, but so are many others, including fats and such. The process is called Dielectric Heating.

      Basically, the molecule being heated is a dipole. It has a positive charge at one end, and a negative charge at the other. In an alternating electric field, it rotates as it tries to align itself with the field. This causes motion, which translates to heat. The heat spreads as the molecules hit other molecules and transfer the energy to them. Now, this process works really good on water because water is a very strong dipole, but it does not operate solely on water, and it doesn't have anything to do with water in particular.

      See, the frequency doesn't actually have much to do with it. Normal kitchen microwaves operate at 2.4 Ghz or close to that. Industrial microwave devices tend to work at 915 Mhz. Also, if the frequency had something to do with it, then 2.4 Ghz would be the wrong one. The resonant frequency for water is somewhere in the 20 gigahertz range. The only reason 2.4 Ghz is used for microwaves is that it's a free bands of frequency (ISM frequency bands) that can be used worldwide.

      So, there you go. Now you know.
      --
      - Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
  2. Out of curiousity... by Krinsath · · Score: 5, Interesting

    Does anyone know how much power is "wasted" (if any) due to using wireless methods versus wired connections?

    Off my limited knowledge, it would seem to be akin to one of the problems with biofuels...they currently take more energy to produce than they store. So will using this technology to charge a device result in taking two or three times more energy to transmit the same amount of power to the device, or is there no discernible difference between wireless and wired?

    Just wondering is all...

    1. Re:Out of curiousity... by Abeydoun · · Score: 4, Interesting
      Here's the Wiki I found on general wireless energy transmission.

      From the wiki article

      "WiPower [1] technology is a very recent example of inductive charging technology. The charging pad allow users to charge multiple electronic devices that are placed on its surface. It is insensitive to the position or orientation of the devices under charge. Unlike most inductive charging systems, the WiPower system uses air-core technology which allows the system to be integrated into very small electronic devices. The efficiency of the system actually exceeds many corded chargers which have a median efficiency of 57%."

      --
      The only consistency in life is the lack thereof
    2. Re:Out of curiousity... by snowraver1 · · Score: 3, Interesting

      200 years ago people would never fly.
      150 years ago it was impossible to talk to someone in another town
      125 years ago it was impossible to own a car
      50 years ago it was impossible to own a computer (except for banks, schools, and gov't)

      You never know what the future might hold. Cold Fusion might prove to be possible. Zero point energy might be proved and harnessed. Maybe someone will figure out a way to take the heat out of the atmosphere and make electricity from that.

      My point is, and I do have one, that nothing is impossible. There is more that we don't know then we know... Chew on that.

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