Dave Liquorice wrote:
On Thu, 10 Mar 2011 11:31:59 +0000, The Natural Philosopher wrote:

You will get far more familiar with this as more silly wind power is
added to the grid.

I'm not overly keen on this frequency based automatic load shedding
(as in switching off) either. Sounds like a recipe for grid
instabilty if you ask me. Frequency drops, lots of stuff drops off
line, Whe Hey! too much capacity frequency goes up, stuff comes back
online, frequency drops...


No, that's not a problem really..as there are time delays and hysteresis
built in.

But the whole thing is pretty silly really as the amount of kit that can
be load dumped in this way is probably vanishingly small.




And how much stuff is about that can be switched off for an
indeterminate period without warning?

Exactly.

Not a lot, storage heaters
maybe but they aren't on when there is peak demand and you could only
switch 'em off for a limited period otherwise people would be
cold(er) the next evening.

Some form of dynamic load directly controlled by the grid would work
but I'm skeptical about an open loop system.


Actually it isn't open loop, the feedback control is in the frequency.


I am very mixed about this, On the one hand its a small effect, and wont
save the planet, on the other hand its actually bloody simple and cheap
to build into - say a fridge freezer - the intelligence to do it and
to move the largest part of that load to off peak times.

Probably a far fare better way to modulate demand, would be for people
to work 24x7, preferably from home, and spread the 'human activity' part
of the load throughout the night as well as the day..

Frankly this is just another bit of 'this will help a teeny bit, but
such a teeny bit its barely worth spending money on' like switching off
the telly at night, that's been blown up to 'This will save the planet'
by the eco-fantasists and the 'green' big business interests.