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Re: dams and electricity



Pumping surplus water uphill using surplus electricity can provide water for
irrigation and water for generating extra electricity during peak demand.

These are both done at places like Grand Coulee Dam. Lake Roosevelt is the
main body of water contained by the dam. When Lake Roosevelt water is
plentiful, and during off-peak power demand, some of the "generators" can
become pumps to pump water from Lake Roosevelt up about 280 feet into Banks
Lake. The water in Banks Lake can be used at later times for irrigation, or
run back through the generators to supply peak-demand electricity. This is
nicely explained on several web pages starting at the Grand Coulee Dam home
page at... http://users.owt.com/chubbard/gcdam/

But the project in Georgie doesn't sound very smart to me. The Lake
Hartwell project, as described by Mark Kossover seems to be missing several
key parts. (1) We pump water to a high place when we have water to spare.
It sounds like the Lake Hartwell region doesn't have water to spare. (2) We
pump using electricity generated during off-peak usage. It doesn't sound
like Lake Hartwell system is equipped with excess reversible generators like
Grand Coulee Dam is equipped. (3) You have to pump water from one lake to a
higher lake, using electricity generated at the lower lake or some different
lake. Running water out of Lake-A, through generators, into Lake-B, then
using that electricity to pump water from Lake-B back into Lake-A is a
losing proposition with no benefit of any kind as far as I can see.

If Lake-B is too full and Lake-A is too low, and if there is a generating
station where Lake-B goes into Lake-C, then the B-to-C generators could
provide electricity to run pumps to transfer some water from Lake-B to
Lake-A during off-peak demand at the B-to-C generating station. If this is
what is proposed in Georgia then it might have some merit. But this
requires surplus water in Lake-B, and a generating station as B goes into C
that has excess generating capacity at some times.




Michael D. Edmiston, Ph.D. Phone/voice-mail: 419-358-3270
Professor of Chemistry & Physics FAX: 419-358-3323
Chairman, Science Department E-Mail edmiston@bluffton.edu
Bluffton College
280 West College Avenue
Bluffton, OH 45817