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.