EMF below Power Transmission Lines

[FFjhh]

TL;DR Summary

Been thinking about this off and on for years.

Many years ago I was responsible for maintaining the integrity of a buried fiber optic cable that utilized a railroad right-of-way. Kinda like watching submarine races !

Along much of this routing, transmission towers / power lines would be adjacent to the railroad. Talking with railroad personnel, they would tell me of voltages accumulating on the rails with visible arcing sometimes happening.

With this in mind, I’ve often wondered if it would be possible to harness this power by utilizing some type of monitoring / collection system placed directly beneath these transmission lines.

I suppose that given enough information, an estimate could be made as to the available power that could be accessible to an accumulation system. This is beyond my ability.

So if anyone has already gone through this exercise, I would be most interested in hearing.

So as a mind exercise, I have been thinking of methods to harness or measure this power.

Some assumptions and questions come to mind regarding an apparatus to do this.

- Some layout of conductors beneath the lines would of course be necessary.

- Parallel to the above lines or perpendicular to ?

- would a circularly polarized collection device offer any advantage / disadvantage over a linear one ?

- I assume that any collection device would require the use of the Earth as a second contact point (ground), or not ?

- I assume that transmission lines were the standard 60Hz, here in the US ?

- How might the magnetic fields come into play in a scenario for collection such as this ?

- What might a ferrous conductor wrapped with a copper conductor produce below these lines ? DC current ?

- The below is from a WHO document. I'm having a bid of a time understanding exactly what the 10 kV m^-1 means ?

The highest electric field strength at ground level from overheadlines is typically around 10 kV m^-1 (AGNIR, 2001b; NIEHS, (1995)

https://www.who.int/peh-emf/publications/elf_ehc/en/ (Chapter 2)

Any thoughts or links to articles that may be helpful toward this understanding would be appreciated. Short of maths from calculus and above though !

thanks, jack

 

[Nugatory]

I’ve often wondered if it would be possible to harness this power by utilizing some type of monitoring / collection system placed directly beneath these transmission lines.

You can get power that way, but you aren't harvesting free or otherwise wasted energy - you're stealing it from the power company. It's illegal in many jurisdictions, and if you aren't an expert in power transmission engineering it's also seriously dangerous.

It's easy to think that energy is just going to waste when you see a charge being built up on the railroad rails... so why not harvest it? But that's not what happening. Power is voltage times current, and there's no current flowing when a voltage difference builds up between the rails, so no power loss from the power line - we just have a more than usually complicated electromagnetic field in the vicinity of the power line. But as soon as you start drawing a current from the rails you are taking power from the power line to maintain that voltage, just as if you were taking power from a stepdown transformer on the line.

So can be done, but it's as unethical as any other theft, dangerous, and maybe illegal. Don't do it.

 

[Nugatory]

Closed under our policy for discussing illlegal or dangerous activity