On Thu, 17 Sep 2009 01:35:51 +0100, Kennedy McEwen wrote:

Dinorwic is an impressive site, the speed that it can get synced
and
online at full power is quite amazing. But it can't run for very
long
before the water up top runs out. It's there for the peaks not the
base load.

Checkout http://www.dynamicdemand.co.uk/grid.htm

Hum interesting but I think based on a false premise that the grid
has the *exactly* the same frequency *everywhere*. The frequency will
be close but not exact, the many sets that supply power to the grid
are not connected by a hard physical link but by a relatively elastic
one of the long reactive grid distribution lines.

I wonder what effect having lots of load that came on/off in response
to the (supposed) overall demand and supply ratio would have on grid
stability? With the time lag that it takes to bring ramp up supply
from coal/oil stations you couldn't really have stuff switching in
much less than 1/2hr IMHO and you wouldn't want all these things
doing a switch at the same time (a few minutes) relative to a
supposed dip/rise in grid frequency.

As I said interesting but not as simple to do as it first appears.

--
Cheers
Dave.