Qlders our biggest generator

Queenslanders were our biggest “generator” and saved millions during electricity price surge

In yesterday’s power system chaos, sparked by the fire at Callide C, Queensland consumers were effectively the biggest generator, while electricity price surges resulted in an increase in the total price of electricity traded of $218m over 6 hours. 

“The biggest impacts are obviously felt at Callide, in the workforce and surrounding communities. We are relieved that no one has been reported injured but we know that the stress and uncertainty is continuing there,” said Queensland Conservation Council Director Dave Copeman.  

“The majority of Queenslanders were impacted yesterday and stepped up to help the system. Queensland consumers provided more effective generation than Queensland's gas power stations, by listening to advice and reducing demand by 900 MW between 6:30 and 7pm, compared to the day before.”

At this time, the Queensland wholesale electricity price was $15,000/MWh. The value of reduction in demand, the money saved by Queensland energy users at wholesale prices, was $6m just between 6:30 and 7pm. 


While Queenslanders using less electricity reduced the cost of the catastrophic failure of Callide C, the price impacts are still significant. If all of the electricity traded between 2pm and 8pm in Queensland yesterday was bought at the wholesale price, it would have cost $230m compared to $12m in the same period the day before. The actual settlement will be determined by commercial-in-confidence forward contracts held by energy retailers and generators. 

“It’s too soon to say that the impact of the price spike during this 6 hour period won’t be passed onto Queensland businesses and households” 

Forward contract prices will certainly be affected by the risk assessment of future catastrophic failures in Queensland coal fired power stations. 

Queensland’s Energy Minister, Mick de Brenni, today recognised that it was Queensland’s diverse energy grid, including consumers, which kept the lights on last night.

Yesterday afternoon exposed the vulnerability of a power system relying on large, ageing coal fired generators. 

Investment in large and community-scale renewable energy, transmission assets and storage facilities can provide reliable, clean, safe energy for the future.

Further information on the events of yesterday is provided below. 

25 May Timeline

While there are still many questions to be answered, it is worth outlining the facts and timing of events that we can be certain of due to National Electricity Market data. 

  • At 1:30pm, just before the fire, rooftop solar was meeting nearly 25% of Queensland’s demand. Large scale solar and wind contributed another 20%. 
  • Immediately after the fire, between 2 and 2:30pm, Powerlink were unable to maintain system security, leading to tripped transmission lines and substations in CQ and a combined loss of more than 2.5 GW, on top of the loss of 700 MW that Callide C was generating. A further eight coal units across Callide B, Gladstone and Stanwell tripped or powered down, as well as 11 large scale solar farms and 2 wind farms.   
  • That led to the huge power outages, as nearly 400,000 customers lost power as Powerlink and AEMO had to shed around 2 GW of load. 
  • The recovery period started from 2:30pm with the surviving Gladstone units, imports from NSW and Braemar and Oakey open cycle gas turbines (OCGT) starting to replace lost generation between 2:30 and 3pm. 
  • At 3pm Stanwell was able to start bringing its three units back up to full capacity as they had not been fully tripped off but powered down to “house load”.
  • Most customers had been restored by 4pm, but the looming evening peak caused AEMO to issue a Lack of Reserve notice. 
  • Roma OCGT and Wivenhoe pumped hydro started generating around 4pm. 
  • Swanbank E gas turbine started generating around 6pm 
  • Gladstone coal fired power station was able to recall two of its units at 6 and 7pm.

There will be detailed investigations in coming weeks into the response of each generator. This will need to explain why:

  • CS Energy was unable to lift generation at Kogan Creek;
  • CleanCo did not generate at Wivenhoe before 4pm or start Swanbank E until 3 hours after the event and
  • other gas fired generators on the Darling Downs did not respond as quickly as technically possible.