Re: Basic Choices and Constraints on Long-Term Energy Supplies

[Richard Tarara <rbtarara@SPRYNET.COM>]

> [Original Message]
> From: Bernard Cleyet <anngeorg@PACBELL.NET>

> Is the major energy demand from manufacturing?

One big piece is (and will be as long as there is a viable economy), but in
the U.S. heating is about 20% of the demand, cooling 5%, transportation
about 20%, agricultural uses about 15%.  Lighting is only 2-3% overall.
These figures often get confused when the media gets involved because they
often equate ENERGY with ELECTRICAL ENERGY, but as JD has pointed out,
electrical demand is only on the order of 20% overall.  [That figure too is
a moving target depending on whether you discuss end use or gross energy
use--since 50% of the electrical energy is derived from coal (and more from
oil and gas) and you have only about a .32 efficiency factor from thermal
to electrical energy.]

Anecdotes about individual conservation methods or home built solar
collectors are fairly useless in trying to plan for a population of 300
million or more.  Most homes and businesses cannot be economically refitted
to be 'green' and it will take a lot of social engineering to change the
life-styles of those millions to consume less.  Even then, then overall
demand will not really go down (population--growth and immigration
factors).

Rick

****************************
Richard W. Tarara
Professor of Physics
Saint Mary's College
Notre Dame, IN 46556
rtarara@saintmarys.edu

**********************************************************
FREE:  Windows and Mac Instructional Software
www.saintmarys.edu/~rtarara/software.html
***********************************************************>