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Storing wind-generated energy as gravitational potential energy? - Page 22

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Posted by David Hansen on December 7, 2008, 6:07 pm
On Sun, 07 Dec 2008 12:40:28 -0500 someone who may be Neon John

Don't assume that anyone who disagrees with you, "just don't
understand the magnitude of the energy problem."

No form of electricity generation produces electricity continuously
at full output. It is necessary to understand their individual
foibles to understand the issues.

"Different types of generators operate at a range of capacity
factors - during 2004, gas power stations had a capacity factor of
around 60 per cent, nuclear 71 per cent, hydro 37 per cent, pumped
hydro 10 per cent, and coal 62 per cent. Meanwhile, the overall
average capacity factor (or load factor) for the UK electricity
network is around 55 per cent.

"Clearly this does not mean that the UK electricity network only
operates for 55 per cent of the time, and that the remaining 45 per
cent of the time no electricity is generated! What this figure means
is that all the generators connected to the network produce in a
year a little over one-half of their theoretical maximum output.

"Why does this occur? The main reasons are that electricity
generators must be switched off for planned maintenance, that
mechanical failure forces generators to be switched off at times,
but also that generators will only be run if there if there is a
demand for the electricity they are producing.

"As a result, it is not possible for any generator to achieve a 100
per cent capacity factor - to do so would mean a perfect operational
record, without a single hour of down-time due to maintenance or
mechanical failure, and an electricity demand level that never
varied. This has never been achieved on the UK (or any other)
electricity network."

and it was written by someone who knows a little about electrical

Pumped storage systems were and are expensive to build. They were
built because when nuclear stations conk out, because of their size,
they leave a large hole in the electricity supply. Because they are
very slow to react, other nuclear stations cannot cover this hole.
Because of the magnitude of the hole, coal fired plants cannot cover
it in the short term. What is needed is something which will start
almost instantly and cover the hole for long enough for coal fired
plants to be wound up. That is a hydro plant. By making it a pumped
storage plant the excess electricity produced by nuclear plants can
be absorbed overnight and it can have a far higher power output than
a "simple" hydro plant would have for an equivalent volume of water.

A good example of such a plant is Dinorwig, which can produce as
much  electricity as a nuclear power station within seconds, using
just four of its six units <http://www.fhc.co.uk/dinorwig.htm> . In
order to perform this trick the turbines must be spinning in air,
synchronised with the external system. When doing this they either
take a little electricity from the external system, or they take a
little of the output of another turbine. From a standing start it
may take as long as a minute to produce full output, though I guess
45 seconds is more typical.

  David Hansen, Edinburgh
 I will *always* explain revoked encryption keys, unless RIP prevents me

Posted by Neon John on December 7, 2008, 7:55 pm
On Sun, 07 Dec 2008 18:07:36 +0000, David Hansen

Before we go on, might I ask if you have any utility experience at all?  As a
retired nuclear engineer, I like to know about the folks I debate with.

What I see is gross incompetence.  Especially in the nuclear area.  Perhaps
some of your engineers ought to come over here and talk to some of our
engineers.  As an example of what CAN be done:


the juicy part:

"he 104 nuclear plants operating in 31 states also achieved a record-setting
average capacity factor—a measure of on-line availability of power. The 2007
average of 91.8 percent surpassed the 2004 record of 90.1 percent, according
to preliminary figures. Capacity factor is the ratio of electricity actually
produced compared to the theoretical maximum electricity a power plant can
produce operating at full power year-round."

Executive Summary:

US:      92%
YOU:     71%

Sounds like some operators need to go to nuclear Special Ed training.  Neon
John's College of Nucklar Knowledge is open for business....

Here's a little tip from inside the industry over here.  Capacity factors are
going UP because both because refueling outages are being extended past the
traditional 18 months and because the plants and procedures are getting even
more reliable.

Since most of the rest of your article is quoted from something and someone
whom I've never heard of and does not represent your knowledge, I'll end this
round of debate at this point.

BTW, we have quite a number of pumped storage plants, among the largest being
Raccoon Mountain near Chattanooga, TN.  I happened to have a large involvement
with that plant, from working heavy equipment moving dirt and hauling the
turbine wheels on TVA's private railroad during construction to operations
training before I decided to become an engineer.  I've "been there, done that
and have the belt buckle"


John De Armond
See my website for my current email address
http://www.johndearmond.com  <-- best little blog on the net!
Tellico Plains, Occupied TN
Serenity: That feeling of knowing that your secretary will never tell either of
your wives.

Posted by David Hansen on December 7, 2008, 8:18 pm
 On Sun, 07 Dec 2008 14:55:31 -0500 someone who may be Neon John

You may ask. However, debating people rather than the subject under
discussion is a well known tactic to deflect discussion away from
the subject under discussion to something else.

Yawn. Over-competence and use of figures which don't refer to the
same thing have been known to generate more heat than light. I have
neither the time or the inclination to follow in that direction.

Readers may note that after the bit on capacity factors, which you
responded to, the rest of my posting was about pumped storage
schemes and was written by myself. This is the bit you were unable
or unwilling to discuss.

  David Hansen, Edinburgh
 I will *always* explain revoked encryption keys, unless RIP prevents me

Posted by BigWallop on December 7, 2008, 8:32 pm



Let's all get together, like politicians, and have mass debate.  That's what
they call them you know, mass debaters.

<me chuckles into sleeve>

Posted by Bob Eager on December 7, 2008, 9:22 pm
 On Sun, 7 Dec 2008 20:18:06 UTC, David Hansen

As you are unwilling to discuss what he said. What a surprise.

Nice try.

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