Recapping where the records sit, in ‘record minimum demand’ following Sunday 17th October 2021 (Part 4)

prior to Sunday 17th October

Extreme Low Point

Sunday 17th October 2021

On Sunday 3rd October 2021 (as noted in this second article on the day) there was a new record low point set for NEM-wide minimum demand.  As noted in that article:

1)  A low point for Scheduled Demand (13,273MW target for 10:55 dispatch interval) … which is down on the 13,509MW prior low point from 13:05 on 22nd August 2021.

2) A low point for Operational Demand (13,972MW measured in half-hour ending 11:00).

As a result of what happened on Sunday 17th October 2021 (as noted in today’s ‘Part 3’ article), we see that there was a new record set for ‘minimum demand’ on a NEM-wide basis:

1)  A low point for Scheduled Demand (12,536MW target for 12:55 dispatch interval) … which eclipses the prior record.

2) A low point for Operational Demand (12,936MW measured in half-hour ending 13:00) … which eclipses the prior record.

On Sunday 3rd October 2021 (as noted in this first article on the day) there was a new .

As note in that article:

1)  the low-point for the ‘Total Demand’ figure published by AEMO was 3,672MW as target for the 11:10 dispatch/trading interval.

2) A low point for Operational Demand (3,784MW measured in half-hour ending 11:30).

The Queensland demand dropped extra-ordinarily low on 25th May 2021 in the aftermath of the Callide C4 Catastrophe.

The AEMO Incident Report on the event, published 8th October 2021, reveals that load shedding occurred

1)  not just due to under-frequency load shedding (UFLS);

2)  but also due to low voltage and other factors.

As a result of this, the ‘Scheduled Demand’ level fell to 2,870MW in the early afternoon.

The levels for QLD demand seen on Sunday 17th October were close, but did not break the standing record:

1)  A low point for Scheduled Demand (3,751MW target for 11:10 dispatch interval).

2) A low point for Operational Demand (3,869MW measured in half-hour ending 11:00).

On Monday 4th October 2021 (a public holiday, and the day after the two records noted above) NSW set a new low-point record for minimum demand.  As noted in that article:

1)  the Scheduled Demand has dropped under the previous ‘low point in a long time’ with target ‘Total Demand’ reaching a low of 4,617MW for the 11:15 (NEM Time) dispatch interval.

2)  When looking at the (AEMO’s more favoured) ‘Operational Demand’ measure, the new low point was 4,861MW in the half-hour ending 12:00 on the Monday.

As a result of what happened on Sunday 17th October 2021 (as noted in today’s ‘Part 2’ article), we see that there was a new record set for ‘minimum demand’ for the NSW region:

1)  A low point for Scheduled Demand (4,286MW target for 12:20 dispatch interval) … which eclipses the prior record.

2) A low point for Operational Demand (4,425MW measured in half-hour ending 13:00) … which eclipses the prior record.

It was an auspicious Christmas Day 2020 (as noted in this article) when Victoria set a low-point for minimum demand.  As noted in that article:

1)  The Scheduled Demand measured by target ‘Total Demand’ reached a low of 2,259MW for the 12:50 (NEM Time) dispatch interval.

2)  When looking at the (AEMO’s more favoured) ‘Operational Demand’ measure, the new low point was 2,529MW in the half-hour ending 13:00 (NEM Time) on the Xmas Friday.

The levels for VIC demand seen on Sunday 17th October were well away from the record, due to cloud cover for the day.

Note the cloud cover mentioned in Mike’s comment here and by Sarah Lawley here.

On 26th September 2021 (as noted in this article) we recorded a low point for Scheduled Demand in SA down at 184MW for the 13:20 dispatch interval (NEM Time).

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In conjunction with this, the (AEMO’s more favoured) ‘Operational Demand’ measure was down at 236MW in for the half-hour ending 14:00 (NEM Time).

The South Australian demand dropped extra-ordinarily low on 26th September 2016 in the process of the SA System Black.

Immediately at the point of the system black event, the ‘Scheduled Demand’ level fell to only 5MW in the early evening.

The levels for SA demand seen on Sunday 17th October were close, but did not break the standing record:

1)  A low point for Scheduled Demand (198MW target for 12:30 dispatch interval).

2) A low point for Operational Demand (238MW measured in half-hour ending 13:30 … very close!).

I can’t recall publishing a single article about ‘minimum demand’ in Tasmania … as it’s a ‘mainland region affliction’ that it seems TAS has been somewhat immune against – due in part to the relatively low penetration of rooftop PV systems in the Apple Isle.

However in the interests of completeness, I’ve did try to have a quick look at numbers in NEMreview v7  and see that there are a number of different dips to what appears to be ‘unnatural low points’:

1)  Including the two lowest points noted in the next column…

2) … But not limited to those.  I don’t have time today to try to comprehensively exclude all ‘unnatural low points’, so will just leave these records blank for now

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BLANK, and to fill in later.

I did find this article published back on Monday 23rd February 2015 about a significant trip of Tasmanian demand.

As a result of this trip (and after checking in NEMreview v7) I can see that:

1)  The Scheduled Demand measured by target ‘Total Demand’ reached a low of 413MW for the 01:05 (NEM Time) dispatch interval on 23rd February 2015.

2)  Noting that records for (AEMO’s more favoured) ‘Operational Demand’ measure don’t go back before 11th December 2014, the lowest points I can see were both 552MW … and occurred:

(a)  In the half hour ending 01:30 (NEM Time) on 23rd February 2015; but also

(b)  In the half hour ending 16:00 (NEM Time) on 21st December 2014 (which appears to be another occasion of ‘unnatural low point’ … at which point ‘Scheduled Demand’ was 543MW).

The levels for demand seen in Tasmania on Sunday 17th October 2021 are well above ‘minimum ever’ measures.