NSW power supply on 16 March 2023 so tight that AEMO had to issue emergency response directions

This is part 3 of the series “Can NSW replace Liddell?”

The 16th of March 2023 was the 2nd hottest day in a late summer in NSW.

Fig 1: Temperatures in Sydney in March 2023

At 5:31 pm the Australian Energy Market Operator AEMO had to issue a RERT direction (market notice 106711 16/3/2023 5:31 pm), the last procedural step before load shedding. RERT=Reliability and Emergency Reserve Trader.

Fig 2: Power generation in NSW 15-17 Mar 2023

Fig 3: AEMO direction 106711 to supply power

The following table shows the market notices which appeared in a short period of time in the late afternoon-early evening:

AEMO market notices 16 Mar 2023 for New South Wales


Notice number Time of notice Notice For period Reserve required
Reserve available
106700 4:34 pm Actual Lack Of Reserve Level 1 (LOR1) 16:00-19:00 1,385 901
106706 5:03 pm Forecast Lack Of Reserve      Level 2 (LOR2) 18:00-18:30 700 682
106711 5:31 pm Direction. AEMO has issued a direction to a participant in the NSW region From 17:35
106716 5:54 pm Actual Lack Of Reserve          Level (LOR2) 17:50-18:30 700 372
106724 6:38 pm Cancellation – AEMO Intervention Event – trading intervals From 18:35
106726 6:57 pm pm Cancellation of Actual (LOR2) condition From 18:55
RERT=Reliability and Emergency Reserve Trader

Only 372 MW away from load shedding even after the direction, for around 1 hr. How did we come to this condition?

Coal generation down by 1,500 MW

Vales Point VP5 said good bye at midnight

Fig 4: Vales Point unit 5 generated 450 MW before being turned off

It is actually planned maintenance.

Fig 5: VP5 planned maintenance until 9 May 2023

What an irony. It is the very coal fired power plant which Czech brown coal baron was allowed to buy (FIRB approval)

Sale of Vales Point: How will Czech brown coal baron Pavel Tykac with
business registered in Liechtenstein impact on NSW coal and energy markets?

Fig 6: Coal powered generation afternoon 16 Mar 2023 max 6,700 MW

So generation from coal was down by 1,500 MW during peak hrs. The 12 units in operation were utilised at 94%

Gas power generation hit maximum

Fig 7: Output of 4 gas peakers was 94% of capacity

Wind power generation variable

Fig 8: Generation from windfarms

Afternoon generation was declining similar to what happened on 6 Mar, but on a higher level of around 900 MW later in the evening.
Just as the winds started to slow down there was a sudden drop of output at 6 windfarms over 15 min shortly before 5 pm, followed by a gradual resumption over 1 hr. Gullen Range, Cullerin Range and Crookwell 2 are in the same area suggesting there was a local problem.

Grass fire at Curraweela

with AEMO market notice 106705 advising that the Mt Piper to Bannaby 5A6 and 5A7 500 kV lines were affected

Fig 9: 11 windfarm locations in the Southern Highlands NSW

But there were simultaneous output drops in windfarms elsewhere (Singleton near Broken Hill, Crudine Ridge south of Mudgee and Boco Rock south of Cooma). It is not clear why there was this coincidence.

Hydro power reached 93% of capacity

Fig 10: Both Upper Tumut and Tumut 3 increased their hours of operation

Peak hydro generation reached 2,300 MW, 100-200 MW higher than on 6 March. Total energy provided over 10 hrs was 12,400 MWh, 50% more than on 6 March.

Fig 11: Operation of Snowy pumps

On 16 Mar 2023 pumps had provided 3,103/6,288 = 49.5% of the generation delivered on the same day. Multiply by 80% for friction losses.

Power imports

Fig 12: NSW imports power from both Queensland and Victoria

In the above graph, imports are positive, exports are negative. Imports from Queensland in the afternoon were limited to 2 short periods and hardly more than 200 MW while usually these imports are between 400 MW and 1,000 MW over the whole day.

Fig 13: Queensland power generation maxed out on 16 Mar 2023

Coal generation was limited to 6,300 MW due to the Callide C power plant still under repair

Fig 14: Callide C may come back only end of 2023

With gas providing 2,500 MW close to capacity (CCGT 96%, OCGT 90%) even Diesel up to 250 MW had to be used.

Queensland had its own lack of reserve level 2, announced by AEMO notice 106719 for the period starting at 17:30 (560 MW required, 531 MW available). It lasted until 18:55.
Fig 12 shows that Queensland can only export during sunshine hours as already mentioned in this post:

30 Jan 2023
When the sun sets in Queensland, energy guzzler NSW is on its own

In Victoria, the situation was completely different.

Fig 15: Victoria’s power generation 16-18 Mar 2023

There was almost 2,700 MW of wind power at the critical time of 6 pm. This allowed exports of 580 MW which grew to 1,500 MW at 10 pm, out of which, however, 500 MW went to South Australia where wind power had declined by 250 MW and died down completely overnight.

Price spikes

Fig 16: Price spike of $14,500/MWh in NSW

The price spike(s) lasted for 1 hr between 17:45 and 18:50 hrs.

Summary and conclusion

That aging coal plants require more maintenance is a no-brainer. Therefore, it is worthwhile to monitor NEMWEB’s list of plant availability to avoid surprises. And as these plants are withdrawn from service the power supply system becomes more vulnerable to ever changing weather events which are quite different from State to State. Limited capacities of pumped hydro and gas peakers impact on the availability of power exports under adverse conditions. Energy guzzling NSW is in an almost continuous state of energy generation deficit which will worsen when Liddell is closing. Power imports are taken for granted just like Australia’s fuel imports. Government departments, Councils, media, major companies and developers do not seem to be aware of this situation, don’t care, ignore it or assume technology will solve any problem in time. This complacency will have financial consequences similar to what we saw with the collapse of road tunnels (Lane Cove, Clem 7, Airport Link) when the first phase of peak oil was ignored.

The latest example of energy illiteracy in Western Sydney is this proposal:


Related posts:

Lack of reserve on hot day in NSW as Liddell power plant is scheduled to close

8 Mar 2023
Can NSW replace Liddell? (part 1)