Switch off at the socket?

In message , J G Miller
writes
On Wednesday, October 7th, 2009 08:52:16 +0100, Tim Lamb suggested:

Using waste heat for space heating only works if you have generating
plant in the middle of towns and you don't have warm summers:-)

Metz, Lorraine has warm (compared to England) summers and the CHP there,
one of the oldest in France has worked efficiently and successfully.

http://www.uem-metz.FR/site/_activites_chauffage.php

In 2005 UEM added a second network of 15 km and 88 sub-stations,
with 300 clients.

My schoolboy French was stretched until I found the translate button:-)

They don't mention overall efficiency either Winter or Summer but I note
hot water is available for bathing etc.

regards

--
Tim Lamb

On Wed, 07 Oct 2009 17:27:10 +0100, Brian wrote:

"Synchronised and spinning-in-air emergency load pick-up rate from
standby: 0 to 1,320 MW in 12 seconds"

That isn't particulary impressive, the switch from full pumping to
full output is the impressive figure, as you have to completely
reverse the direction of rotation of the turbines. Can I find that
fugure now... but it's well less than a minute.

One of the design briefs for the station was that it was to be capable
of supplying power quicker than gas-turbine plant, and it was designed
accordingly. This will not generally be true of conventional hydro
schemes.

They can still go from zero to online full output in pretty short
order, ie. a couple of minutes.

No sure how fast you can bring up a gas turbine set. All the gas
turbines I've come across have to warmed up for several minutes
before you can wind up the output and that's little ones like you
find in helicopters.

--
Cheers
Dave.

John Wright wrote:
Brian wrote:
On Wed, 07 Oct 2009 14:30:01 +0100, John Wright
wrote:

snip

ISTR that Dinorwig could run from zero to full power in about 2
minutes. Any hydro scheme should be able to do that too.

The reality is rather more impressive:
http://www.fhc.co.uk/dinorwig.htm

"Synchronised and spinning-in-air emergency load pick-up rate from
standby: 0 to 1,320 MW in 12 seconds"

One of the design briefs for the station was that it was to be capable
of supplying power quicker than gas-turbine plant, and it was designed
accordingly. This will not generally be true of conventional hydro
schemes.

Though there is no reason why it need not be.

the key to fast load pickup is to have a genny spinning and synched to
the mains frequency and phase locked, being driven BY the mains, or at
least idling more or less in neutral. Then feed in steam or water or
whatever to make it contribute.

Its an alarming thought, but what keeps the mains steady through all the
short term fluctuations is nothing more nor les than the rotational
inertia of a hundred turbine shafts..

something you wont have with windmills, which are not phase locked
mechanically.

Dave Liquorice wrote:
On Wed, 07 Oct 2009 17:27:10 +0100, Brian wrote:

"Synchronised and spinning-in-air emergency load pick-up rate from
standby: 0 to 1,320 MW in 12 seconds"

That isn't particulary impressive, the switch from full pumping to
full output is the impressive figure, as you have to completely
reverse the direction of rotation of the turbines. Can I find that
fugure now... but it's well less than a minute.

One of the design briefs for the station was that it was to be capable
of supplying power quicker than gas-turbine plant, and it was designed
accordingly. This will not generally be true of conventional hydro
schemes.

They can still go from zero to online full output in pretty short
order, ie. a couple of minutes.

No sure how fast you can bring up a gas turbine set. All the gas
turbines I've come across have to warmed up for several minutes
before you can wind up the output and that's little ones like you
find in helicopters.

thats why they sit on hot standby, wasting fuel spinning so that the
lights don't go out in Denmark when the wind drops.

On Thu, 1 Oct 2009 16:19:49 +0100, "Bill Wright"
wrote:


"Java Jive" wrote in message
.. .
I wonder how long it would take to repay the energy invested in
building it, how long it would take to silt up, and what, if any, the
solution to such a problem might be. These points would need to be
very carefully assessed.

Oh they'll do that all right. They're very clever men. We don't have
cock-ups in this country.

Bill


All coils will be wound with ****z wire.

Derek

On Thu, 17 Sep 2009 16:01:59 +0100, The Natural Philosopher
wrote:


natural radon is the greatest source of radioactive related deaths in
the country, by IIRC a factor of several thousand over the nuclear industry.

Bizarrely enough, or so I believe, coal fired power stations actually
emit more "radiation" than nuclear due to the radioactive content of
the coal

On Thu, 17 Sep 2009 16:01:59 +0100, The Natural Philosopher
wrote:

Happy birthday, I have now put my glasses on and realised this thread
was from a year ago

Albert Ross wrote:
On Thu, 17 Sep 2009 16:01:59 +0100, The Natural Philosopher
wrote:


natural radon is the greatest source of radioactive related deaths in
the country, by IIRC a factor of several thousand over the nuclear industry.

Bizarrely enough, or so I believe, coal fired power stations actually
emit more "radiation" than nuclear due to the radioactive content of
the coal

This is apparently so.

Albert Ross wrote:
On Thu, 17 Sep 2009 16:01:59 +0100, The Natural Philosopher
wrote:

Happy birthday, I have now put my glasses on and realised this thread
was from a year ago

Still thoroughly relevant today, with the data emerging about how
ghastly and useless wind and solar power really are, and the government
in a flat spin over carbon floor pricing.

On Tue, 21 Sep 2010 19:29:54 +0100, Ericp
wrote:

On Tue, 21 Sep 2010 11:39:22 +0100, Albert Ross
wrote:

On Thu, 17 Sep 2009 16:01:59 +0100, The Natural Philosopher
wrote:

Happy birthday, I have now put my glasses on and realised this thread
was from a year ago

TFFT!

I have been trolling up and down the past months looking for it and
was about to complain to the provider about missing threads. )

I should do some archiving, I just found a new thread attached to one
from years back which prompted me to look through the rest of the
group seeing what else I missed, this was a false positive.

Still available on Giganews, they have about seven years of usenet
archived now and about two years of binaries