From: dean@vexcel.com (dean alaska)
Subject: Electricity Efficiency
Organization: VEXCEL Corporation, Boulder, CO
Distribution: usa
Date: Thu, 23 Jul 1992 22:01:22 GMT


Since the EPRI report has been the subject of a recent thread, I thought
I should clarify some aspects that I have quoted.  The efficiency
percentages quoted are MTP figures, which stands for Maximum Technical
Potential.  MTP values have been computed for a wide variety of
replacement technologies and represent the percentage of total U.S.
electricity demand which would be saved if every piece of technology
of this type was replaced in the U.S.  Obviously they represent best
case estimates since all old equipment will never be replaced.  How
close we come to the MTP for a particular type of equipment depends
on how strongly we pursue retrofitting.  Although a hard push to
reach these efficiencies would cost more in capital investment, it
could reinvigorate the U.S. economy through both the creation of new
jobs and the availablilty of new competitive technologies that could
raise the MTP even further.

Along with the percentage value is a cost value in cents per kwh for each
type of equipment.  This number combines the retrofit cost and the 
electricity saved by the retrofit amortized over the life of the unit
at a 5% discount rate.  Since this savings is essentially
permanent, as opposed to conservation savings which can be short-lived,
it is often referred to as new capacity ("negawatts")
although it isn't actually so.

A graph of MTP figures has % electricity (or maybe GWH) on the
horizontal axis with the cost value on the vertical.  The curve is 
actually a step function with the width of each step representing the
MTP savings for a particular type of technology and the height of 
each step the difference in cost from the
previous type of equipment to the next one.  The ordering of the
equipment types is in increasing order of cost so that the step function is
always rising.

Lower MTP figures usually represent a cutoff at some cost, indicating
cheaply available efficiencies while the higher percentages include
more expensive retrofits.  The cheaper technologies are:

	Industrial Process Heating	~$.007/kwh
	Residential Lighting
	Res Water Heating
	Comm Water Heating
	Comm Lighting
	Comm Cooking
	Comm Cooling
	Comm Refrigeration
	Industrial Motor Drives		~$.025/kwh
	Res Appliances
	Electrolytics
	Res Space Heating		~$.033/kwh

The MTP values vary from < 1% to about 10% for ind motor drives and about
5% for comm lighting.

As to the issue of economic growth without increased electricity supply:

	These well-established methods [DSM] are so effective that when
	Southern California Edison Co had a peak load of 15 billion
	watts, in 1983-1984, it was able to reduce its forecast of
	peak demand by more than 500 million watts in a single year.
	At the same time, California's appliance and building standards
	increased electricity savings even more.  Annual savings
	represented 8.6% of the utility's peak demand at the time and
	cost the utility only about 1% as much as building and running
	a new power station.  If all Americans saved as much electricity
	as fast as those 10 million did, the U.S. economy could grow by
	several percent every year while total electricity use decreased.

	Scientific American 9-90
	note: DSM = Demand Side Management

Obviously we are not talking about wishful thinking, but methods that
are tried and proven successsful in one of the largest urban areas in
the U.S.
-- 

		dingo in boulder	(dean@vexcel.com)
Newsgroups: sci.environment,sci.physics,sci.energy