ttbn,

I didn't mention unremarkable weather.

What I described as unremarkable was small outages due to equipment failure, like the one that affected part of Happy Valley yesterday. These sorts of problems occur in every state, and usually get fixed quickly.

I have no reason not to believe SA Power Networks rather than a second hand report on unspecified media (talkback radio?) and I don't think SA Power Networks has anything to lose from the truth being known, but they have much to lose if they're caught lying.

I don't understand your "outhouse rat" comment. Was it another pathetic attempt at trolling? And do you actually have any evidence that two more gas-fired plants are slated for closure next year?

___________________________________________________________________________________

Bazz,

That makes a lot more sense, but why would the closure of Hazelwood make any difference?

I would expect the amount of power an AC interconnector can handle would be limited by heat, thus able to greatly exceed its continuous rating for a short period. Is that not the case?

No Aidan, it's not the case. There are several ways that a high voltage main can fail, but by far the most certain is to suddenly change the load.

Collapsing support towers on a line servicing a high, extremely reactive load like a steel works is a very good way to do that.

I've just read the press versions of the analysis of the SA power problems.

The official line is that the loss of the lines caused “significant voltage dips and loss of load,” which is precisely what I suggested. That was exacerbated shortly after by a series of wind turbine shutdowns, which I have to think was a management problem. As I said in an earlier post, the turbines should have been already shut down if the wind was so high.

As a result of all that, the network couldn't maintain synchronisation and failed.

It's a great chance to learn.

It is beginning to look like Renewables had a direct role in the SA blackout.

http://www.theaustralian.com.au/opinion/south-australia-blackout-interim-report-makes-renewables-defence-look-foolish/news-story/f3ea0e20ed6e6fce83e405f4ad48e47d
http://www.theaustralian.com.au/national-affairs/south-australia-blackout-jay-weatherill-insists-outage-caused-by-severe-weather-not-renewables/news-story/58f63d1d4502b34fcceb3ee8773d67c1

There is enough in the interim report to make the rush to defence of renewables mounted by special interest groups and conflicted state governments since the lights went look foolish.

Certainly, the power would not have been lost were it not for the big storm. And seven big towers were damaged in the lead up to the blackout. But AEMO said data currently available indicates that the damage to the Davenport to Brinkworth 275 kV line on which 14 towers were damaged “occurred following the SA Black System”.

The big event was a 123 MW reduction in output from North Brown Hill Wind Farm, Bluff Wind Farm, Hallett Wind Farm and Hallett Hill Wind Farm at 16.18.09. Seconds later there was an 86 MW reduction in output from Hornsdale wind farm and a 106 MW reduction in output from Snowtown Two wind farm. No explanation was given for the reduction in wind farm output.

But the loss of wind farm production put too much pressure on the electricity interconnector with Victoria which cut off supply. This in turn led to a shut down at the Torrens Island power station, Ladbroke Grove power station, all remaining wind farms and the Murraylink interconnector.

AEMO says a lot of work is needed to fully explore what happened.

But definitely there are lessons here for putting high levels of intermittent renewable energy into the electricity system. The speed with which renewable energy spruikers rushed to argue otherwise is a measure of their ideological self interest.

ABC news came to the opposite conclusion, so I had a look at the report itself, which is at http://www.aemo.com.au/Media-Centre/-/media/BE174B1732CB4B3ABB74BD507664B270.ashx

It clearly explains the loss of power from the wind farms was the result of multiple transmission system faults (due to damage from the weather).

So it looks like the ABC's right and The Australian is wrong. No surprise there; after all that's the paper that's so against wind power that once had a front page story proclaiming that Victoria's wind turbines had failed to reduce that state's CO2 emissions... but failing to mention that this was because they were exporting more power to NSW!

And surely an ideological self interest in limiting environmental damage is something that everyone should have?

__________________________________________________________________________________

Craig, why does a sudden change in load cause a high voltage main to fail?

No, it's not beginning to look like renewables had a big role at all, Shadow Minister. It's still looking like it was poor network management and a couple of catastrophic failures of support structures for transmission lines.

With all due respect, this is a highly technical subject, which is very difficult for trained people to understand let alone lay people the FUD being spread by political mischief makers like yourself. You should stick to things you understand, like...erm...never mind, there must be something.

The wind turbines should have been shut down pre-emptively, allowing the central generation network time to adapt, assisted by the gas turbines which exist for that purpose. That way, even if the transmission lines had collapsed, the network was in a stronger position to cope, although I suspect it would still have failed.