In article ,
polygonum writes:
On 30/04/2013 12:44, Andrew Gabriel wrote:
Germany doesn't have a grid - it's part of a much larger sychronisation
zone which covers all EU countries between Portugal and Romainia, and

Oops, 'EU' should have said Europe. (It's nothing to do with the EU.)

is controlled from Switzerland. (Also includes some north african
countries via a Gibraltar link, but I doubt that passes a large amount
of energy in relative terms.)

Originally all the eastern (political) european countries were part of
the USSR synchronisation zone, but they've been gradually moving across.
It was an interesting issue when the Berlin Wall came down - the West
was 50Hz +/-0.1Hz, and very short of power, and the East was 50Hz +/-1Hz
(but often a larger drift), and with a surpless of power, but very poluting
power generation.

Out of genuine ignorance, I ask what aspects of German and our
electricity distribution make it "not a grid" there, but "a grid" here?

The post was talking about 50Hz stability, but Germany doesn't control
that - it's part of a single synchronisation zone covering lots of
countries (including Italy which was also mentioned), which have a
single supply infrastructure. This is the zone over which supply and
demand are matched using directly connected sychronised generation.

We are also connected to this, but not sychronised - we are our own
synchronisation zone and separate grid, and our 50Hz can drift against
the Europe 50Hz.

2GW loss is a much smaller proportion of the European zone than it is
of our zone.

Quite obviously, there are cables between power stations and consumers.

Quite obviously, and you state it, there are standards to which they
adhere for frequency.

So what makes Germany (and the other countries) a synchronisation zone
but not a grid?

It is a grid, but covers all the countries in the Zone, not just Germany.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]