Re: Worrying about the long term (was Global Warming (NUCLEAR))

[Rick Tarara <rbtarara@SPRYNET.COM>]

----- Original Message -----
From: "Robert B Zannelli" <Spinoza321@AOL.COM>
To: <PHYS-L@lists.nau.edu>
>  Rick >>
> Rick I can't question your numbers because I don't have at my fingertips
the
> actual percentages involved. However I must admit surprise that a doubling
of
> fleet averages translates to a modest 5 percent saving in energy use.
However
> I think it's indisputable that you are correct when you say that given
> current rates of population growth, conservation will not be enough.
>
> Bob Zannelli


While it doesn't seem right this is exactly one of the reasons that the
energy debates get so skewed....we don't have very good instincts about the
actual numbers concerning energy supplies and demands.  I always give a
prequiz in my energy class asking what percentage of the energy used in the
U.S. is electrical in form (students say 50-90%, answer about 30%), how much
of the total energy is supplied by nuclear energy (students 25-50%, answer
about 5%), etc.

With transportation, one must first know that transportation consumes 27% of
the energy used in the U.S. and cars/pickups/suvs account for about 40% of
that total.  That's 11% of the total consumption.  Therefore, increasing the
ACTUAL mileage up to about 40 mpg (currently about 20) saves less than 6%.

Only after really slogging through all these numbers can one really get a
feel for the enormity of the task of providing sufficient energy for the
future. Another example--to provide 20% of our projected energy needs in
2100 with Wind requires several million 500kW-1MW generators and this
doesn't account for storage schemes that could reduce the overall efficiency
and thus double or triple this number.

Rick

(Trying to finish updates on the World Energy Simulator for posting next
week.)

**************************************************
Richard W. Tarara
Associate Professor of Physics
Department of Chemistry & Physics
Saint Mary's College
Notre Dame, IN 46556
219-284-4664
rtarara@saintmarys.edu

FREE Physics Instructional Software
www.saintmarys.edu/~rtarara

Win9.x, WinNT/2000,  Win3.x, Dos, Mac, and PowerMac
New: Updated versions of the Energy Simulators
Windows and Mac  CD-ROMs  now available.
****************************************************