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Is it possible to build an instrument which can generate wireless electricity?

I ask this since at present the electricity was passes through wires and i thought about wireless electricity

I am curious to know about this:

Is it possible to build an instrument which can generate wireless electricity ?
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2 Answers 2

up vote 1 down vote accepted

To transport the electricity we need some electrons that can move. This is very common in metals but cannot normally happen in air or vacuum. Of course there are some exceptions: for instance in nature we have lightnings, where a plasma is formed, in man-made machines such as particle accelerators we have some free electrons (or protons or positron) in vacuum.

Other energy vectors can be transported easier through air or vacuum, for instance electromagnetic (EM) fields. So we need to build a device which converts electricity into high power EM waves and another one which can convert them back to electricity. One of the simplest demonstrator you can build is made of a light bulb (electricity --> light) and a small solar panel (light --> electricity). Of course you will have a lot of losses in this process: a first improvement may be putting a mirror behind the light bulb so that you concentrate the light to the panel. Then you may switch to a laser and optimise the panel for that frequency, or you can go to microwaves and use some coils to capture them.

You may also think about something else: for instance you can power a fan with some electricity and capture back the wind energy with another fan. But if you consider this three points:

  1. Efficiency
  2. Achievable range
  3. Cost

you will easy realise that where a wire can be placed, is very hard to beat it.

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Induction can create an electric current over a 'small' gap. See for example http://en.wikipedia.org/wiki/Inductive_charging.

Also electromagnetic waves contain energy and can therefore be used to create electricity at a distance. This is used in some ideas for space based solar stations, where they use microwaves to transfer the energy from space to the earth.

Edit: Some more links

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so as per link we can generate it but upto some extent isn't it? –  BlueBerry - vignesh4303 Aug 21 '12 at 10:31
1  
No, We can generate it up to a larger extent which is already been pointed out by @Laar but its efficiency would be too low for commercial power transmission... –  Waffle's Crazy Peanut Aug 21 '12 at 13:26

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