Xref: utzoo sci.electronics:20748 sci.energy:5178
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!emory!wa4mei!ke4zv!gary
From: gary@ke4zv.UUCP (Gary Coffman)
Newsgroups: sci.electronics,sci.energy
Subject: Re: Gold saves energy.
Message-ID: <2943@ke4zv.UUCP>
Date: 7 Jun 91 17:40:36 GMT
References: <1991Jun5.163512.1314@zoo.toronto.edu> <1987@ole.UUCP>
Reply-To: gary@ke4zv.UUCP (Gary Coffman)
Followup-To: sci.electronics
Organization: Gannett Technologies Group
Lines: 20

In article <1987@ole.UUCP> ssave@ole.UUCP (Shailendra Save) writes:
>
>   Someone please verify the skin effect stuff.

Skin effect is of negligable effect at power line frequencies, bulk
conductivity still rules. If you raise the frequency to take advantage
of skin effect, you start to run into radiation losses as the length of
the conductors becomes an appreciable fraction of a wavelength. For
typical spans, most of the electrical energy would be lost to radiation
across only one span at less than 2 Mhz.  300/Mhz defines the wavelength
in meters for a given frequency.

Long distance transmission today uses DC at ultra high voltage to minimize
the amount of current the conductor is required to carry for a given 
amount of power. Power loss is proportional to I^2*R, so the lower the
current, the lower the loss for a given conductor. Use of DC rather than
AC eliminates radiation losses over the long spans of long distance power
lines.

Gary