Wireless transmission of electrical energy

What power level and how far? Why do you need to do this?

Yes! You needed to talk to a guy named Tesla but he's no longer with us. Power companies do this all the time with high voltage transmission lines over the objections of many people living nearby. If you try to receive this unwanted electromagnetic radiation however you are considered a thief.

Very well put. I say there you have it well sussed out. Brains as well as fingers.

Here's a previous thread discussing the subject:

http://cr4.globalspec.com/thread/4102#comment23846

You can use radio waves to transmit energy, but this is not the same as transmitting electrical energy, as such, where you are actually moving electrons from one place to another. In transmitting electrical energy, you are pushing electric charge through a wire. An electron beam, such as you'd find in a CRT or an electron beam welder, is probably the closest thing to 'transmitting' electrical energy without the use of conductors.

You can transfere some energy by extra low frequency 20-50Khz by inductive means. It takes so much to broadcast the power that it would never be of a practicle use.

When Tesla tried it out he took down a power station. He was experimenting with inductive lightening. The generators over loaded and caught fire. He did manage to transmit 10,000 Watts over a distance of twenty six miles. (42 Kilometers.) See patent No.645 576 issued to N. Tesla on 20 March 1900. for further details. US patent office.

See a book called.

The man who invented the twentieth century. By Robert Lomas.

ISBN. 0-7472-7588-2 published 1999. Headsline Book Publishing.

OK, I'll bite. Did he actually transmit 10KW over 26 miles, or transmit 10KW and it made it 26 miles out? In other words - did the receiver 26 miles out receive 10KW?

Yes his load was 10Kw of lighting.

Yes, being a Tesla-coil fan, I've read quite a bit about his Colorado Springs experiments. But the poster specifically asked about transmitting electrical energy without wires. Not RF energy, or transmission of energy by means of electric and/or magnetic fields, but the (implied) transmission/movement of charge. Electricity.

Wish I'd been there to see Tesla's own experiments live. That would've been something!

Maybe we shouldn't be so quick to pshaw this idea (I looked it up, not a verb but it's a word). I have this cordless optical mouse that has two batteries for breakfast.

You can also transmit electrical energy through space - this happens all the time with the solar wind, and other particles. It's not unusual to build up a charge of many 100 volts on a space craft - this static charge has to be equalized before two space craft can dock.

Yep. Spacecraft can build up a hellacious charge. Megavolts, under ideal conditions.

Particle beams can travel through space for some distance, but they tend to fan out much more quickly than, say, a light beam, because of mutual repulsion among the particles. The higher the current, the faster the beam-spread.

Why do you argue that RF energy is not electrical energy? If you can run a load from it it must be transmitting power in order for work to be done. RF carries both magnetic flux and electrical flux. Transformers would not work if this were not the case. RADAR would not function and on and on.

See original post, paying particular attention to the words electrical energy and conductors. RF energy and charge transport are fundamentally different, yes?

That's being pedantic. If work is done as a result of either process they should both be considered to have transfered energy. The way it is worded is slightly ambiguous.

Magnetic energy from RF transmissions can light up flouresent fixtures without wires. Try it, hold a tube near to a transmitting antenna i.e. Radar on a boat. This is how we used to confirm output fro these transmitters.

Of course they can, and I've done it myself. But is the same as the juice from your outlets? Can you see any difference at all between charge transport and radiated RF? Why do you think the OP mentions conductors, specifically? Maybe in association with the fact that conductors transport charge? Hello?

Europium--

Yes, the original post mentioned conductors, but also mentioned "electrical energy", not just electricity or electrical charge. I believe the sense of the question permitted answers such as the ones you are railing at.

Without realizing it, we are using wireless transmission of energy at a fairly low level every day--witness RFID (Radio-Frequency IDentification) tags which are becoming almost ubiquitous in stores and many other locations. They get their power from the host device's carrier wave, and use this power to broadcast their data.

I never knew of Tesla's experiment, and am impressed. I also am worried about unintended side effects or consequences of any attempts to do energy transmission using wireless methods. Technology has the characteristic of creating a problem every time it solves another.

JMM

You can get just as dead touching a high powered transmiter ariel (ant) as a mains conductor. ZAP. that one. RF has two parts the magnetic and the electrical.

I have thought about this for years as my whole electrical life is based on limits.

When you get this figured out let me know . . . and tell me how to size bus capacity. Do I add more . . . what? Space? Air? . . . to increase the load carrying capacity of ? What about insulation? What should I ground? And can I still use the word ground?

My wife has Tesla beat as she transferred 10 MW of energy across a distance of 2 meters (power density much higher) when I told her she looks like she added about 5 kilos in the past month.

George a.k.a 'lonely boy'

Yes it is called Taser Gun just ask anyone that has been shot.

taser guns still have wires...

look into free air laser links. basicly you shoot a laser at a solar cell.

http://www.spie.org/web/oer/december/space_laser.html

http://en.wikipedia.org/wiki/Wireless_energy_transfer#Light

http://ieeexplore.ieee.org/iel5/9039/28689/01286285.pdf

that'll get ya started...

Airships Industries launched a project for a geo-stationary airship for telecoms purposes in about 1994 which would be powered by solar cells and a microwave link transmitting 100kW, ground to ship. The airship's outer skin would be covered by a mix of solar cells and micowave aerials. In the opinion of an eminent microwave engineer this was feasable considering the size of the receiver, his estimate of efficiency was 10%. I recall there was much discussion about aircraft safety and bird mortality.

Tesla must be the record holder of the worst electrical smog ever made.......and some people worry about holding a mobile phone near to their heads!!!! (I know the frequencies are dissimilar, but look at the power differences!!!)

Does anyone know if Tesla ever had a hunchback and mumble things like "The Bells, the Bells" or similar?

I would expect that today, sending out such quantities of electrical energy would shut down satellites, ruin TV & radio programs for miles around (you might have a good idea here at that!!), heat up and old amalgum tooth fillings so that the mercury can leach out better and give cancer to all foetuses around for miles.......it might even cause the cosmic wind to backup too!!!

....and it is completely inefficient too!!!

Aloha,As far as I know,the only person who could have answered that question would have been Nicolai Tesla. And we all know what end he met attempting to do just that!

Yes. - Its called 'radio`. Energy density decreases as the cube of the distance.

Considering that a broadcast radio station might put out kilowatts of power, and the receiver might receive a milliwatt of power (on a good day), it is not very efficient... like 10^-6 of the power might reach the receiver.

Now this could be improved by using parabolic antennas (like a satellite dish) at either end. At 60 Hz, a wavelength would be 5 x 10⁶ meters. A marginal dish might be 4 wavelengths in diameter or 2 x 10⁷ meters in diameter... I don't think it would fit in my back yard. Somehow I don't see it happening.

Well said. How right you are!!!

besides myself being an "experienced optimistic", whenever I hear "...Somehow I don't see it happening..." I tend to follow with agreement, intuitively grasping that doubt is usually more reliable than hope. May God forgive me.

Now, I know this is a terrible generalisation to make, but given the above said, I'll stick with it, this time at least

Yes.

Yes, there is. It is a very common concept. It is called electromagnetic induction. In fact, Nikola Tesla, through the use of tesla coils( high voltage resonate air core transformers,) to transmit electrical power distances said to be greater than several miles to power lights. This was in the late 1800's/early 1900's.

The problem is efficiency, would you pay an electricity bill probably a 1000 x higher than you pay now? (of course it will depend on how far away from the transmitter you are, for a doubling of the distance the bill will be at least 4 x higher....unfair on those living farther away....)

Do you really believe that electric supply companies would put all these wires everywhere if there was a "Wireless" method as good?

Do you want to live in such gigantic electric smog, when people even today feel that just being near a wire with mains running thru it might be dangerous in the longterm?