"Andrew Gabriel" wrote in message
...
In article o.uk,
"Dave Liquorice" writes:
On Mon, 29 Apr 2013 12:55:31 +0100, The Other Mike wrote:

http://www.dailymail.co.uk/news/arti...rother-switch-
fridge-Power-giants-make-millions--pay-sinister-technology.html

I know it's the Mail but WTF do you start with the ******** it spouts.

I haven't read that, but I listened to the spokesman from the
european power generators association (whatever it was called)
being interviewed on this issue at lunchtime today.

"Can shut down supply without warning - or your consent"

That's the main function of smart meters, which I already mentioned
in another thread.

There will be something buried in the User Guide that gives your consent
by the simple act using the appliance. That happens already for lots of
things.

In the graphic it says demand surged during the Royal Wedding. I doubt it
was during but immediatly afterwards when everyone leapt up for a cuppa
and a wee (pumps coming on to supply water and take it away). Not even
sure that 2.4 GW is correct either and if it is it's probably one of, if
not the, largest load pickups ever and can be planned for and is why we
have Dinorwic.

"Sensors in domestic appliances would check this frequency every 0.2
seconds, and if it fell to 47Hz - a level that would risk blackouts - the
devices would kick in and shut fridges, freezers and ovens down."

Only "risk" blackouts at 47 Hz? The limit 50 Hz is +/- 0.5 Hz. I reckon
if it ever got down to 47 Hz there would be power stations tripping out
left right and center.

This is for EU-wide product supply.
UK had historically aimed to maintain +/-0.1Hz for no other reason
than CEGB had controls good enough to do so.
Much of the rest of the EU aims for +/-1Hz, and there may be some
EU synchronisation zones even outside that range.
The appliances will have to cope with the worst case.

"If the frequency of the supply nudged towards 52 Hz, the devices could
make fridges become cooler, increasing demand and balancing out the
system."

And probably all the substation fuses will pop, dropping loads of
load suddenly and unexpectedly, causing the frequency to rocket up
through positive feedback as all loads are shed.

Pardon, do I really see what I'm reading? HTF can a switch make a device
use more energy? Or are they saying it switches on when it doesn't need
to?

There's actually a large timing range for things like fridges (and
even more, freezers) that can cycle on/off without going outside
temperature spec. They do represent an excellent opportunity to store
energy. For example, if you know you're going to have a mass toilet
flushing and kettle boiling at the end of a royal wedding/funeral,
you could switch on freezers beforehand so they drop an extra 1C,

In don't think that's gonna work with "frost-free" ones. Surely they resist
being "turned on early" to go a little bit colder

tim