On Mon, 28 Mar 2011 17:40:24 +0100, The Natural Philosopher
wrote:

But realistically, how much fuel do you save if you shut a coal plant
down to idle for a few days while the wind blows... the efficiency is
utter crap when you do that.

Indeed it is. Some years ago, not too long after privatisation, so
keen was one very large coal fired power station to carry on
generating right round the clock and effectively be always on base
load, they routinely bid a very low price into the system - way below
their actual cost. Payment at that time was made to all generators on
the bars on an equal basis being determined by the cost of the last
one required to meet national demand. Things were tweaked (can't
recall how) to allow the nukes to carry on running round the clock to
avoid xenon poisoning problems with step changes of loads on the gas
cooled reactors. So it was only coal, gas and oil that effectively
bid into the system. The underbidding kept efficiency right up, and
their emissions improved a bit. Significant money was being made.
Load factors were high and investors were happy.

Then one balmy night the **** hit the fan, the load dropped a bit more
than normal, as someone got their sums really wrong. I'm not entirely
sure how this situation was handled, but someone, somewhere,
effectively made a few million quid that night (at say GBP20/MWh) on
what had suddenly became a zero cost product across the country.

After that episode this generators always bid somewhere a bit closer
to their actual generating costs.


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