Re: An Interesting Take on Green Energy

["Chris McGookin" <chris@xxxxxxx>]

Neil,

you're right in saying that coal, gas and oil stations can take a few days
to run up, but all that the operators do is turn the boilers up and down-
they keep them warm and run them up depending on the required load profile.
This is done routinely throughout the day and night to match the amount of
electricity (they don't generate when they're on simmer ;-) ).
Hence the output is really quite dynamic.Modern gas plants in particular
can be online very fast (around 30 mins I think).
Nuclear cannot operate in this way, they run at the same power all day,
every day that they can and take days to get there.

As such the pumped storage 'batteries' are more than likely to be using
more nuclear generated electricity than anything else- especially when you
consider that they generate over 20% of the total grid output 24 x 7...
As does storage heating, etc...

Cheers,

Chris

----- Original Message -----
From: Neil Fuller
To: ukha_d@xxxxxxx
Sent: Monday, April 07, 2003 4:15 PM
Subject: Re: [ukha_d] An Interesting Take on Green Energy


Mark

I see the point you are trying to make but my understanding is that the
electricity used to pump up is part of the excess capacity that exists
during periods of low demand.

It takes 2 - 3 days to get a coal, oil or gas fired power station on-line
from cold (much, much more for nuclear) so they have to keep the generators
spinning overnight. The energy thus produced is in effect wasted  if it's
not used (it's much more complicated than that but to keep this simple,
just accept it!!)

So, in a slightly twisted way, they are green in so much that the heat
chucked up the chimney keeping the generators spinning is not wasted just
as BF&W losses.

In a similar way, during periods of high demand, hydro electric (and
especially Dinorwic in N.Wales) can supply sudden surges, almost at a
moments notice. So, when you get up to make a cuppa during the adverts,
think of the 10ft valves opening up within 10 seconds, deep in a N.Wales
mountain to supply the grid with the surge.

All in all, they use a variety of generating technologies to smooth the
peaks and troughs of demand.

Finally, if you are ever near Llanberris, I highly recommend a tour around
Dinorwic - The generator hall is big enough to fit St Pauls in and it's all
housed deep in the heart of a mountain. If you are remotely interested in
engineering it's fascinating.

Regards

Neil
----- Original Message -----
From: Mark Marooth
To: ukha_d@xxxxxxx
Sent: Monday, April 07, 2003 12:57 PM
Subject: [ukha_d] An Interesting Take on Green Energy




I used to work for Scottish & Southern Energy (Scottish Hydro as was)
and can
perhaps give you an interesting spin on green energy.

A number of the Dams operated by Hydro are in fact called pumped storage
systems.  I was told that Hydro would pump water up into the
dams at night using excess supply from the grid and would then run that
water
through the turbines during the day and charge the prevailing day rate to
supply the lecky back to the grid.

So, where do you think the cheap power comes from at night, again I was
told
principally from nuclear plants and the Scotland/England
Interconnector, meaning brown energy.

There is no doubt that SSE has a good green portfolio and is a
profitable/responsible company (Still a shareholder) but some things are
not
necessarily what they seem.



Mark