Some wrongly implicated windfarms when the entire state lost power after one of the worst storms in 50 years knocked out high-voltage power pylons

On Wednesday, something very unusual happened: the entire state of South Australia lost power. Known as a “system black,” it’s something the Australian Energy Market Operator (Aemo) had only prepared for in theory – never having the unfortunate opportunity to put “black start” procedures into place.

What caused the blackout?

The cause was very clear. And it was not due to renewable energy (see next section).

One of the worst storms to hit South Australia in 50 years knocked out 22 high-voltage power pylons. The lines on those pylons carry electricity generated near Port Augusta to the rest of the state.

South Australia blackout: entire state left without power after storms Read more

When they went down, a cascade of automatic safety switches appear to have been flipped, in order to protect the rest of the SA power network – and indeed the rest of the National Electricity Market.

Besides creating power, generators also affect the voltage and the frequency of the electricity network, which need to be carefully maintained to protect everything that’s connected to it.

Aemo carefully models how that is likely to change in the short, medium and long-term, so that the networks can then make sure it’s sitting at the right values.

When the 22 high-voltage power pylons were blown over, a huge chunk of power generation was cut off from the rest of the network.

Dylan McConnell from the Melbourne Energy Institute says the market operator can’t prepare for very rare events like this.

“They’re black swan events,” he says. “If they did plan for this, then there still might be something else that could happen, like an earthquake. A system capable of dealing with this would be very expensive.”

To protect generators and equipment in SA, the whole high-voltage power system was cut, which in turn removed supply from the local distribution networks.

In addition, to stop the voltage and frequency fluctuations affecting Victoria, the lines connecting SA to Victoria (the “interconnectors”) were also shut down.

The result was that at about 4.20pm, the entire state of South Australia lost power.

What did wind power have to do with it?

Nothing. Nick Xenophon, Barnaby Joyce and others have been out blaming wind power for the blackout. But it is simply not true.

Just before the blackout occurred, windfarms were producing about half the state’s electricity demand – they were not shut down as a result of the high winds. And ElectraNet, the owner of the downed high-voltage lines, made clear the blackout was caused by the storm damage to their network.

If the recently closed Port Augusta coal power station was still operating, it would have been cut off by the downed distribution lines too. And that would have likely made the disruption worse, since it would have created an even bigger sudden change to the network.

But that didn’t stop politicians and most media outlets reporting the false information.

The deputy prime minister, Barnaby Joyce, said on Sydney radio station 2GB this morning: “Obviously we know that South Australia has had a strong desire to become basically all renewable energy and the question has to be asked does this make them more vulnerable to an issue such as what happened last night.”

“If you turn power into just a complete social policy and say well we are going to save the planet one state at a time and in so doing you create vulnerability to your state, so that if it comes under stress with a severe lightning storm, as they did, that this makes it more likely that you will have a total blackout,” Joyce said.

South Australian senator Nick Xenophon, who has often expressed anti-wind sentiments, also jumped on the bandwagon. “We have relied too much on wind rather than baseload renewables, rather than baseload power, including gas which is a fossil fuel but it is 50% cleaner than coal and a good transitional fuel,” he said.

The irony is that if anything, more wind energy might have actually made the system more robust against this sort of rare event. The disruption occurred because of a sudden change to the network’s generation. And that happened because so much power was cut off at once. If there was more generation distributed around the state, it might have limited the impact of the loss of the transmission lines.

How did the system cope with the outage?

Remarkably well, it seems.

While smaller blackouts occur reasonably frequently around the country, this appears to be the first time that any state has experienced a complete blackout.

Since the National Electricity Market was first established, it’s had procedures for how to turn a system on from a complete “system black” but it has never done it before.

That plan was put into action quickly and as of 11:42am this morning, about 80,000 South Australians were still without power. Aemo and the network operators were moving to progressively and safely restore power everywhere. Below is a map of which areas were experiencing blackouts at 11am.

McConnell says doing that is no simple matter, and the fact Aemo started to get power generation back into the network within hours was a great feat.

Map: number of people affected by power outages in SA