Compared to yesterday’s (moderately) high demand event across the NEM, this morning in NEM-Watch we saw a much-more-bluish colour in both Victoria and South Australia – see the snapshot here at 11:15 NEM time:
In contrast, we notice the higher temperatures in NSW (and particular the population centre of Newcastle-Sydney-Wollongong) driving demand in NSW higher – already, in the NEM-Watch snapshot from 11:25, we see demand above 12,000MW (so already higher than yesterday’s peak):
Note the AEMO warning (Market Notice) of low reserve capacity in NSW for this afternoon. Clicking on the Market Notice heading within NEM-Watch opens the full text of the notice in Notepad – with the message saved here for your reference:
As noted in this image, an LOR1 notice is the least-severe of the AEMO warnings.
However at 12:45 we see AEMO has issued another Market Notice warning of a forecast LOR2 level for later this afternoon (from 14:00 to 15:00 NEM time, so 15:00-16:00 NSW time). This coincides with the real-time warning calculated by NEM-Watch of a low Instantaneous Reserve Plant Margin (IRPM) in the NSW Economic Island (845MW spare, or a margin of only 7% – whereas typically the system is more comfortable above 10%):
Given the tightness of the supply/demand balance, it was no surprise to see the occasional price pop up close to the market price cap into the afternoon – such as this example from 13:35 market time:
What was more of a surprise was to see the demand flatten off over the prior hour (compared to the morning’s forecast), as noted in the image above. No doubt something to do with the storms progressing through the western areas:
However by 13:50 we see that AEMO had issued an “Actual LOR2” Market Notice (from 13:30 market time) warning that available reserves in NSW had dropped below the 2nd warning level (meaning, in simple terms, that a large unit trip would probably result in some loss of load):
As it turns out, the NSW demand today peaked 5 minutes before this snapshot – with a level of 12,822MW at 13:45 – thereafter commencing a steep decline as the storm front cooled proceedings markedly, as shown here an hour afterwards in the 14:45 snapshot with demand now 1,550MW lower than today’s peak:
Not surprisingly, we see prices have subsided.
This cool change will have satisfied overheated residents in the Newcastle-Sydney-Wollongong area. It might have also cooled off some sweaty brows amongst those responsible for maintaining AEMO’s impressive record of keeping the lights on…