[LINK] NBN Smart Off Peak Appliances Needed

[Richard Chirgwin]

Ben -

Fifteen-all.

Some grid applications are medium-bandwidth for each node, and there are 
lots, so it would add up to a bucket across a network. We tend to have a 
very narrow focus when talking "smart grid" - that it's all about the 
consumer side.

The consumer applications, by all the matrices I've seen, are 
low-to-medium bandwidth. Full demand-side management, which is far more 
than just "switch to off-peak", would start to aggregate some serious 
bandwidth by the time you got back to the exchange (say, 20k households 
all sending current consumption data at the same time, receiving an 
air-conditioning instruction, for eg).

IF you want to use the telecommunications network to run this stuff - 
ok, if the NBN is there, you might as well - there's actually a fibre 
advantage. You can cordon-off a very small virtual circuit 
(terminology?) that's only carrying the electricity data. This has two 
advantages: (1) if there's a realtime emergency, you don't have to worry 
about jitter caused by different congestion and router paths depending 
on which retail ISP is carrying the data; and (2) the electricity 
control data never touches the Internet (because only a brain donor puts 
something like that on the Internet anyway).

But the "good stuff" in the electricity network probably happens a step 
away from the consumer. How many pole transformers are there in 
Australia? A million, more or less? (happy to accept correction here). 
Nearly all of them will be passed by fibre. That gives you a damn fine 
basis for fine-grained fault-finding and diagnosis.

If fibre was of zero relevance to electricity suppliers, why do they 
have so much of it? Currently, the fibre I know of in electricity 
networks runs from 300 kV grid systems, down as far as local substations 
(maps I've seen under NDA). That last step, out to local transformers, I 
assume is too expensive and hasn't been done.

(Site note: I would imagine that if the distributors are awake, they're 
quietly talking to NBN Co, because some of them have fibre where even 
Telstra doesn't go.)

So yes: a simple off-peak switch doesn't need the NBN, and only a damn 
fool would use the Internet for it. OTOH, there's good stuff that can be 
done with fibre and electricity, if you don't use bandwidth as the main 
criterion.

Cheers,
RC

On 14/08/12 10:45 AM, Ben Elliston wrote:
> On Tue, Aug 14, 2012 at 08:54:31AM +1000, Richard Chirgwin wrote:
>
>> Since the "it's time for offpeak" message is still a very simple
>> signal to send, why bother with the Internet?
> Precisely.  Stephen Conroy was trying to use the smart management of
> appliances as an example of why we need the NBN.  Really .. a very
> slow serial line would be more than sufficient.
>
> Cheers,
> Ben