Again, I am NOT talking about who is paying for anything! I am not talking about money at all -- in any shape or form.

If I am coupled closely to the transmission lines, my drawing power from it affects the transmission. It might be small and hard to measure, but it does affect it. But as I decouple the two more and more, at what point is the source no longer affected by the receiver? At some point things have transitioned from being a transformer-like interaction to being a purely one-way transmitter-receiver interaction.

When I use a crystal receiver to listen to an AM station, all of the energy that is in the signal I am listening to comes from the transmitter. But, if I am a hundred miles away, is it even theoretically possible for the fact that I am extracting energy from the radiated signal to be detected? Does it have any effect, at all, on the transmitter? Or, like the sun, is it a case of zero feedback coupling and that once that energy is radiated beyond some distance, that it is simply gone as far as the transmitter is concerned and whether or not some device in the next county or the next solar system manages to transform and utilize that energy in some way is nonsensible at the transmitter?

At the point were it's not longer a transformer effect (reactive power) you have nothing (even less than nano-watt levels of the magnetic device of the OP thread) with a 60 Hz utility line because it doesn't radiate a self-propagating EM wave at any normally detectable or remotely usable energy level with power lines and receiver lines a tiny, tiny fraction of the 60 Hz wavelength needed to get a phase shift (in the EM field) across the conductors due to a changing EM field.

At the far distant transmitter end the effect is undetectable at the transmitter side with loading changes on a distant far field receiver. Something similar been used for spy bugs that don't radiate. The spy bug modulated a "passive cavity resonator" that detected and stored the carrier envelope received energy and modulated the received carrier per the audio modulation in the room. That varying load is detected on a secondary remote receiver listening to the spy bug.

So other radio receivers near each other can detect changes in other nearby radio receivers using energy from a distant transmitter, if you have good equipment.

 

Oh, I completely agree that the notion of getting useful power from far field is (almost certain -- never say never) a fool's errand and the domain of snake oil salesmen.

The use of passive cavity resonators for bugs is one of those examples of (in my opinion) an incredibly clever application of fundamental principles and engineering. While not truly undetectable, it sure comes close in a practical sense.

 

Oh, I completely agree that the notion of getting useful power from far field is (almost certain -- never say never) a fool's errand and the domain of snake oil salesmen.

The use of passive cavity resonators for bugs is one of those examples of (in my opinion) an incredibly clever application of fundamental principles and engineering. While not truly undetectable, it sure comes close in a practical sense.

I can personally say, the old Soviet Era Russians are great engineers and scientists with limited resource. It's was a daily battle with the evil empire.

Obviously, there have been improvements in technology that make detection even harder.

 

When you "steal" energy from the far field you are no longer "stealing" from the producer, you are now "stealing" from the receiver.

I only say this because I live "behind" a tall building that blocked TV transmissions back in the day, and it was very frustrating.

 

Finally watched the video.

They demonstrated < 1pW of power derived from the rotation of earth. Not quite earth shattering.

Tidal generators can actually extract useful amounts of power from the same.

 

Finally watched the video.

They demonstrated < 1pW of power derived from the rotation of earth. Not quite earth shattering.

Tidal generators can actually extract useful amounts of power from the same.

+1 exactly.

IMO this shows the disconnect this type of new energy research has with reality, part of the peer-review process should also be with engineers in the field of research to bring the scientists back to earth. But saying 'bad' things, would risk the grant money gravy train, so that never happens.

The science is cool but the practicality is near zero.

 

 

TLDR, but there's thermoelectric if you can find a temperature differential to exploit (ground vs air vs water). RF energy from radio/TV/etc broadcasts, mechanical sources like sound or vibrations.