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Re: high-voltage transmission losses



I will pass along some info I collected on this topic a few months ago.
It's not much, but it might lead you to some more. I ran out of time
before I got all my questions answered.

(1) I got the loss factors that Baltimore Gas & Electric uses in
conjunction with setting grid rates. Losses are presented as an average
for each voltage level of the different transmission lines:

Primary Voltage
230 kV 0.878%
115 kV 1.622%
34 kV 2.473%
13 and 4 kV 3.660%
Secondary Voltage 6.665%

<http://supplier.bge.com/main/EnergySettlement/BGELossFactors.asp>

(2) The Federation of Electric Power Companies in Japan collects and
publishes information and statistics from a number of nations. The
second URL given below is part of a fascinating presentation of the
world's generation, distribution and use of electrical power; seen
through the eyes of a nation which, by virtue of its geography, is
particularly sensitive to the need for efficient and plentiful electric
power and to the accompanying environmental concerns.

Their statistics for transmission and distribution loss:

1980 1990 1997
Japan 5.8% 5.7% 5.5%
US 6.6% 5.7% 5.4%
Canada 10.0% 7.7% 8.8%

I also ran across a statement somewhere (don't have the source) that
some of the improvement in loss figures comes from improvements in
transformers; the latest generation of HV transformers are so efficient
they can be considered essentially lossless. ???

<http://www.fepc.or.jp/english/data/data07.html>

<http://www.fepc.or.jp/english/info/energyandenv/09.html>

Best wishes,

Larry
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Larry Cartwright <exit60@ia4u.net>
Physics and Physical Science Teacher
Charlotte HS, Charlotte MI USA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Daniel Schroeder wrote:

Living in a state that supplies CA with electricity, I'm wondering
how much energy gets lost along the 700-mile high-voltage lines
between us and them. From the EIA website I know what the
national average is: about 9% energy loss in all transmission
between generators and users. But I have no idea how much of
this loss is on local distribution lines and how much is on
long-distance transmission lines. Does anyone know? Obviously
it would suffice to know the linear resistance of the lines,
but I don't know that either.

Dan Schroeder
Weber State University
Ogden, UT