Why do we not have wireless power supplies?

Question

Why don't we have a wireless adaptor plugged into our power outlets that would allow appliances to draw power from it wirelessly in the same way radio stations transmit large amounts of radio signals or in the same way wireless internet works?

Answer 1

Nikola Tesla experimented with this concept but was unable to figure out how to do it in a safe and efficient manner.

I think the only way this will ever be utilized is sending power to a space station in orbit.

Answer 2

Because that would be far too diffuse to ever be useful. Sure you could have antennas in everything, but you would need an incredibly powerful signal to force the electrons to move enough in just one object... and that's even close to the source; the signal would diffuse as 1/r^2, and who knows what kind of problems that would cause. Not to mention that you'd probably use more power generating the signal than what you'd use. Now, this is used, to an extent, for radio ID tags... a radio emitter causes a signal to be sent back to it from an otherwise unpowered device. However, these devices are very small and specifically designed just to emit a signal back; it wouldn't be able to, say, drive a motor.

Wires a better for power because you move all the power you need directly to what you need, without much loss. Further, you only use the amount you need, because you can turn specific devices off. Think of your electricity bills if you had such a theoretical 'wireless power' device running all the time.

Answer 3

I think most logically the reason is the large amount of loss incurred in transmitting by radio. Plus the large amount of radiation that would be present from each and every device that is operating that way, and then there is the interference factor between adjacent devices, and the large amount of power that theives could steal. I think the main reason is the large amounts of power that would have to be generated for such small amounts to be utilized - efficiency is the word. I hope this is what you were looking for...

Answer 4

the main thing is in wireless transmission power efficiency is less. i.e if you send 100% power at sending end u will receive app 5-10%(not exactly) at receiving end.
in cell phones and radio etc power efficiency is not the Criteria signal reciption is the Criteria in that they wont bother about power efficiency. their intension is to transmit the signal only but not power.

So regarding your question wireless power transmission is also possible, but as told earlier power efficiency is less. so in practical there is no wireless power transmission. if u want wireless adaptor the i/p power should be 10-20 times the original adaptor power

Answer 5

Well you can have a wireless power supply but the problem with it is that you need a good frequency to transmit the energy by. It's an effeciency thing.

Or you could go the way Tesla did. Saturate the air with electricity then put vacuum tubes with a bit of a ruby in them.

Answer 6

You're talking about hi-power microwave links or even hi-power lasers. These technologies exist and work but are obviously incredibly dangerous to have shooting around a home or office.

Answer 7

Because you do not want that much power flowing through you also.

Answer 8

you want 120V flying through the air? ;-)