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From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: sci.electronics
Subject: Re: Living near high tension lines
Message-ID: <2223@kitty.UUCP>
Date: Wed, 11-Nov-87 21:24:12 EST
Article-I.D.: kitty.2223
Posted: Wed Nov 11 21:24:12 1987
Date-Received: Sat, 14-Nov-87 04:54:39 EST
References: <9312@tekecs.TEK.COM> <1718@bloom-beacon.MIT.EDU> <1913@frog.UUCP> <390@auvax.UUCP>
Organization: Recognition Research Corp., Clarence, NY
Lines: 52
Summary: Stalking the E-field...

In article <390@auvax.UUCP>, rwa@auvax.UUCP (Ross Alexander) writes:
> Mr Lippmann provides us with an erudite and convincing (to me, anyway)
> rationale which leads one to view claims of free power via m-field
> coupling with suspicion.  Fine.  Could someone, anyone, tell me why the
> E-field couldn't be used instead?  Obviously the impedances would be
> pretty amazingly high; but that's what #40 magnet wire's all about ;-)

	I was afraid that someone would ask that question...

	Consider the following:  To tap the, uh, E-field we run a parallel
"pickup" wire for 1,000 feet in close proximity to the power lines, with this
wire having a diameter of 1 inch and being supported on poles with insulators.
We will assume a separation of 40 feet between the wire and one power line
conductor, and 40 feet between the wire and the ground.
	Using a common formula for power line engineering, this results in
a capacitance of 0.0014 microfarads between the pickup wire and the power
line conductor; considering the reactance to be purely capacitive (not
really true, but close enough for now), we have an impedance between the
pickup wire and the power line conductor of around 1,890,000 ohms.  Assuming
a power line voltage of 365 kV, and since the capacitance between the pickup
wire and the power line is roughly equal to capacitance between the pickup
wire and ground, we have a voltage divider and therefore have around 183 kV
on the pickup wire.
	Using the above 183 kV and 1,890,000 ohm impedance, we would have
a maximum current flow of roughly 0.097 ampere.  If we could somehow directly
utilize the 183 kV, we would have 18 kva of "free energy".  Not bad; that is
more than enough energy to power a small house.  However, in order to get
at this "free energy", we will need a transformer with a 183 kV primary -
neither cheap nor simple - nor a particularly safe do-it-yourself project.
	Actually, the 1,000 feet of pickup wire 40 feet in the air on
poles with huge insulators may make the power company suspicious, although
there is probably not much they can do about it. :-)

> By the way, I have _absolutely_ no idea as to the practicality of this
> suggestion, either.

	See above. :-)

	Actually, there is a useful point that is illustrated by the above
example.  Unenergized wires that are also ungrounded and run in close
proximity to high voltage power lines can pose a serious danger of electrical
shock as they would acquire a high potential due to capacitive effect.
This is why utility company craftspersons working on unenergized lines in
close proximity to energized lines always ground both ends of the line, or
treat the unenergized line as if it were energized.  More than one utility
company employee has been electrocuted through touching an unconnected, but
ungrounded wire running parallel to energized circuits.

<>  Larry Lippman @ Recognition Research Corp., Clarence, New York
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