[posted at 15:20 NEM time]
Remembering late Tuesday 11th February
It was an ominous warning that the AEMO issued in a Market Notice early Tuesday evening for what would eventuate today:
Receiving the full text of this notice via a Local Alarm set within a display copy of NEM-Watch, we read further:
Notice ID : 44980
Notice Type ID : GENERAL NOTICE
Notice Type Description : Subjects not covered in specific notices
Issue Date : 11/02/2014
External Reference : Forecast temperature for SA region for 12 February 2014 exceeds the Generation Capacity Reference Temperature
AEMO ELECTRICITY MARKET NOTICE
Forecast temperature for SA region for 12 February 2014 exceeds the Generation Capacity Reference Temperature
The Bureau of Meteorology has issued a forecast temperature of 43 degrees for Adelaide for 12 February 2014
AEMO requests that Participants review their offered capacities based on the forecast temperature for all scheduled plant in the SA region, and if appropriate, submit reoffers to reflect the revised capacity.
END OF REPORT
It’s not just the wind farms that are affected by weather patterns such as these (we note, in the snapshot from NEM-Watch on Tuesday afternoon above, that the wind farm output had dropped to be as low as 100MW late on this day).
(a) Higher ambient temperatures would affect the maximum capacities, and efficiencies, of practically all the generation plant in South Australia.
(b) We also noted that a planned transmission outage in Victoria had been cancelled because of the risks associated with supplies to South Australia on Wednesday.
Heading home for the day, we wondered what the morning would bring…
Wednesday 12th February
… early the next day we saw that the wind had picked up again in South Australia, dampening the Scheduled Demand numbers shown in NEM-Watch:
As this snapshot shows, Adelaide’s temperature had passed 35 degrees as early as 09:15 market time and (at this time) AEMO was forecasting SA regional Scheduled Demand to stop just short of 3,100MW (well short of the all-time record).
As the day progressed, we saw a few blips in pricing, such as this seen here at 11:10 NEM Market Time (11:40 in South Australia):
We can see that the other four regions are stuck in the green zone (indicating modest demand compared to the relevant historical range) whilst we see South Australia progressively crawl up the colour scale, in terms of Scheduled Demand.
By 14:20 the temperature in Adelaide had already soared above 40 degrees, coincident with a drop in wind speeds (and hence production from wind). In a repeat of what happened yesterday, the gas-fired plant have cranked up to meet the increase in Scheduled Demand that has resulted from a combination of temperature-induced demand, and lower embedded generation.
As at the time of posting, Scheduled Demand in the South Australian region reached 2,968 at 15:20, past the demand shown here (2,924MW, measured on a Dispatch Target basis) at 15:10 NEM time:
Taking into account the 284MW net imports from Victoria (346-60MW), the region had 3,260MW of available capacity supplying 2,638MW net demand – meaning a healthy 24% IRPM (Instantaneous Reserve Plant Margin) for the South Australian “Economic Island”.
This is despite the fact that (as shown in the annotated snapshot from NEM-Watch above) that the available generation for scheduled plant in South Australia had declined by about 300MW since the morning – at least in part due to the soaring temperatures.
Incidentally, we see that gas prices at the Adelaide hub were higher today than they have been over recent days (close to $6/GJ), except yesterday ($6.58/GJ ex-ante) – as shown in an image from GasWatch :
Quantities, however, are not substantially different from Monday (when there was much lower gas-fired generation) and Tuesday (much the same as today, as can be seen in the charts above in NEM-Watch).