Even the New York Times withholds the address

Eric Germann ekgermann at cctec.com
Tue Nov 19 22:45:31 UTC 2002

To close this out, look for information on the Tennessee Valley Authority's
Racoon Mountain Pumped Storage Facility.  Take top off mountain, make
reservoir on top, drill shaft down to base of mountain, put generators with
discharge to a lower reservoir.  Its called a peaking plant.  Drain the top
reservoir during peak times and produce electricity.  Cool thing is, the
generators can be reversed and become pumps to pump the water back up the
mountain during off peak hours.

Without going into how fossil fuel fired generation desires to run at a
relatively constant level and has minimum loading requirements below which
it cannot stabley operate at, and hey you can't store the power, so they use
it off peak.  Unlike your house or our bandwidth, within the industry, power
costs fluctuate over the course of the day.  So they take advantage of it.
Closest thing to storing electricity thats possible.  Even though pumping
consumes more power than the falling water produces, the drastic cost
differential over the course of the day makes it economically viable.

On the flip side, their reservoirs are not hundreds of gallons, but hundreds
of acres.  One of the interesting design problems they had to overcome was
how to keep the top reservoir from swirling like a bathtub when all the
generators were online.  And when they open the rather large valves
(measured in tens of feet) for the tunnels, the mountain tends to shake. a
little, at least when you're in the mountain.

Fascinating place to tour.  It was about 15 years ago.  Don't know if they
still do tours, but the geek factor was pretty high if you're into that kind
of thing.  IIRC, they're somewhere in the vicinity Oak Ridge.  We took a bus
ride from ORNL to there for a day tour.


> -----Original Message-----
> From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu]On Behalf Of
> Vadim Antonov
> Sent: Tuesday, November 19, 2002 5:15 PM
> To: blitz
> Cc: nanog at merit.edu
> Subject: Re: Even the New York Times withholds the address
> Just to keep it off-topic :)  The kinetic water-based accumulating
> stations actually do exist, though they use elevated reservoirs to store
> the water.  The water is pumped up during off-peak hours, and then
> electricity is generated during peaks.  This is not common, though,
> because most energy sources can be throttled to save fuel, or to
> accumulate in-flowing water naturally.  However, I think we will see more
> of those accumulating stations augmenting green energy sources (wind,
> solar, geothermal, tidal) which have erratic performance on shorter time
> scales, unless things like very large supercapacitors or hydrolizers/fuel
> cells become a lot cheaper.
> In some cases accumulating stations are useful in places remote from any
> regular power sources because they can minimize energy loss in long
> transmission lines (it is proportional to current squared, while
> delivered
> power is linear to the current).
> --vadim
> On Tue, 19 Nov 2002, blitz wrote:
> > One last addition to this idiotic water idea.. since the water
> doesn't get
> > up there to the reservoir on the roof by itself, add your costs of huge
> > pumps, plus the cost of pumping it up there, and a less than 100%
> > efficiency in converting falling water to electricity. Also,
> add heating it
> > in the winter to keep it liquid instead of solid,
> decontamination chemicals
> > (cant have any Leigonella bacillus growing in there in the
> summer) Its all
> > moot, as the weight factor makes this a non-starter.

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