Thread: Big storm and no power in SA

Go back a few decades, and power was nearly always generated close to where it was used, with no interconnects. Which meant that if anything went wrong, power went out locally, and other areas were unaffected.

With increasing prosperity and lowered costs (for a variety of reasons), interconnection between generating areas became economically feasible. This eventually extended around twenty years ago to interstate connections, enabling the various state grids to take advantage of both different generating assets (e.g. highly controllable hydro, base load coal, peak shaving gas, intermittent solar and wind etc) and different times for peak load.

But as this storm event has demonstrated, having a very large interconnected grid makes the system more easily disrupted, simply because there is a lot more of it over a much larger geographic area. But if you have become too dependent on this interconnection, the whole lot can fall in a heap as happened here.

I don't think you can blame what happened on either the renewables nor on the storm, but on a network that was not sufficiently robust, which it needs to be once you move away from the 'local generation' model.

With S.A. reported as having the highest electricity prices in the country, there is little excuse for this.

John

Originally Posted by DiscoMick

Chinese steel?

All sounds like another reason to go off the grid. I bet there is a spike in sales of stand-alone systems in SA.

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Could well be, these are the newer towers that have been up around a decade at most. Anyway WA is sending over some temporary towers to help us out.

Western Australia sends transmission towers to storm-affected SA - ABC News (Australian Broadcasting Corporation)

Originally Posted by weeds

It would have to be a record with 14 transmission towers toppling.........were there structural issues, maintenance issues or just not good enough for the storm.

23 at last count

The disruption was a programmed safety response.

When wires hit the ground the system destabilised- assets can then be damaged as the grid needs to load shed quickly to avoid damage.

The network did exactly what it is supposed to do.

What brought the towers down was tornado events, causing so much drag on the cables that they pulled a tower over, this then stresses the next and so on...

Once the grid is isolated the areas are then brought back online in a sequence and load added to the grid...

Interestingly the renewables (wind) were the first to come back online...

The Eyre peninsula is currently running on One of the usual 3 HV lines as the other 2 are damaged.

In the meantime Arrium is bringing in 7 trucks worth of power generation to enable it to recommence operations - it requires ~70mwh to run and currently has ~35mwh available utilising some grid AND its own power station.

Even if PTAA Flinders had been running it would have shut down during the event.

Originally Posted by DiscoMick

So is the answer to increase interconnections so there are more available power sources? For example, rather than one interconnect to Victoria could there be more, to Victoria or even NSW?

There are two interconnects with Victoria. Both were disconnected to protect the Victorian grid when the South Australian grid went out of phase.
The same type of protection systems would have protected the working parts of the South Australian grid from the damaged parts of the grid but, with wind generation switched off (to protect assets, the gearboxes don't hold up in high winds), there was not enough capacity in the on line generation systems still working, the whole grid went down.
Had there been a NSW interconnect, that would have been disconnected too.

Originally Posted by DiscoMick

After all, in normal times, I believe Victoria benefits at times by being able to receive cheap wind generated power from SA. Its all one big grid with various power sources.

I, and reality, do not share that belief. Electricity derived from wind is actually quite expensive. Hence high South Australian power prices.

Originally Posted by DiscoMick

So is the problem not how the power is generated, but how it is distributed?

In this case, mainly generated.
Wind and solar PV are intermittant. Great for line regulation but terrible for supplying the power the base load requires (otherwise known as base load power).
Thermal generated power is the heavy lifting power that reliably supplies the power the base load requires.
Thermal can be coal (cheap), gas (expensive), nuclear (unpopular), geological (locality restrictive) or solar (locality restrictive).
A power system can be all reliable but cannot be all intermittent.
In South Australias case, they have focused too much on the intermittent form of low emissions power generation.
I dislike the term "renewables". The term as it is used is misleading. It's really "low emissions".
Real renewables is biomass. What is destroyed can be regrown/renewed.

So the system is designed to shut down to protect itself in an emergency like this. Therefore it makes no difference if the electricity is generated by coal, gas,solar, wind etc - the system would still shut down. Isn't that right? So how can you say SA is over-reliant on wind? The wind system operated normally in this situation. It was distribution which had the problem.


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Originally Posted by DiscoMick

So the system is designed to shut down to protect itself in an emergency like this. Therefore it makes no difference if the electricity is generated by coal, gas,solar, wind etc - the system would still shut down. Isn't that right? So how can you say SA is over-reliant on wind? The wind system operated normally in this situation. It was distribution which had the problem.


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The distribution system is designed to shut down segments at fault.
Because one of the segments at fault was the interconnector, an asset they were relying on heavily at the time for system stability, the whole system went down.
Torrens Island and Pelican Point did not have the capacity to keep the rest of the system up. Had they load shed before the interconnector went down or had another high capacity thermal unit in operation, the system may not have come down.
Were the transmission lines between Leigh Creek and Adelaide disrupted? If not, and the Leigh Creek power station been on line, the power outage may not have happened.

Bear in mind, Queensland have a similar distribution system but a different generation system. A Category 5 cyclone doesn't plunge that state into darkness.

We have 3 HV feeds into the Eyre Peninsula.
If those 3 only 1 remains intact.

It is unlikely we will have full capability for a minimum of a week.

The Operations areas of Arrium are currently minimal - with the BF fully powered to protect it from refractory collapse or going cold (almost worse).

Other areas are about to be augmented with mobile generation.

SA wind farms were actually operating at full capacity according to their output data at the time of the collapse and recovered very quickly once the grid was coming back online.

I still believe Flinders Power (Alinta) should have remained open and looked at other fuel sources (gas etc)