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.

Brian