Recapping the accelerating decline in ‘Minimum Demand’ levels across the NEM, at the end of 2023

The ‘lowest ever’ points for NEM-wide demand are different for different measures:

1)  Measured by ‘Market Demand’, we saw that the lowest ever point was on 1st October 2023  (10,500MW target for 11:35 dispatch interval).

2) A low point for ‘Operational Demand’ was however set on 29th October 2023 (11,009MW measured in half-hour ending 13:30).

Beginning 2023 the lowest point had been at 6th November 2022:

1)  Measuring 11,607 by ‘Market Demand’

… so dropping 1,107MW through calendar 2023.

2)  Measuring 11,892MW by ‘Operational Demand’

… so a drop of 883MW through calendar 2023.

On 1st October 2023 (as noted in this article on the day) we saw lowest points set for demand in Queensland.

As noted in that article:

1)  the low-point for the ‘Market Demand’ figure published by AEMO was 3,017MW as target for the 10:30 dispatch/trading interval.

2) A low point for ‘Operational Demand’ being on the same day (3,131MW measured in half-hours ending 11:00 and 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 ‘Market Demand’ level fell to 2,870MW in the early afternoon.

Beginning 2023 the lowest point had been on 25th Sept 2022 (no article on that day, and slightly lower than 11th Sept 2022).

Into 2023, they had subsequently dropped:

1)  On 19th and 20th August 2023;

2)  Then 17th September 2023;

3)  Then 1st October 2023.

On 29th October 2023 (as noted in this article on the day) we saw that there was a new record set for ‘minimum demand’ for the NSW region:

1)  A low point for ‘Market Demand’ (3,664W target for HH:MM dispatch interval).

… so a decline of 466MW over the year.

2) A low point for ‘Operational Demand’ (3,719MW measured in half-hour ending HH:MM).

Beginning 2023 the lowest point for ‘Market Demand’ had been at 4,130MW on 29th October 2022.

Into 2023, they had subsequently dropped:

1)  On Easter Sunday 9th April 2023.

2)  Then Sunday 8th October 2023.

3)  Then on Sunday 29th October 2023 (3,664MW).

On 31st December 2023 (as documented in Part 1 and Part 2 and Part 3 and Part 4) we saw that there was a new record set for ‘minimum demand’ for the VIC region:

1)  A low point for ‘Market Demand’ (1,456MW target for 13:00 dispatch interval).

2) A low point for ‘Operational Demand’ (1,564MW measured in half-hour ending 13:00).

Beginning 2023 the lowest point had been at on 18th December 2022 …

… ‘Market Demand’ down at 1,980MW.

Into 2023, they had subsequently dropped:

1)  Then on 16th Sept 2023;

2)  Then on 12th Nov 2023;

3)  Then today (31st Dec 2023).

… so a total reduction of 524MW over the year

On 31st December 2023 (as noted in this article earlier today) we saw that there was a new record set for ‘minimum demand’ for the SA region:

1)  A low point for ‘Market Demand’ (-45MW target for 12:30 dispatch interval).

2) A low point for ‘Operational Demand’ (-26MW measured in half-hour ending 13:30).

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 ‘Market Demand’ level fell to only 5MW in the early evening. 

… BUT … it’s since dropped lower still … so that record no longer holds.

That’s even though there’s been a re-basing upwards of ‘Market Demand’ in South Australia with some Non-Scheduled wind farms now operating as Semi-Scheduled:

… these ‘re-basings’ occurred at several points:
(a)  it was 9th December 2021 when some Non-Scheduled Wind Farms (like Canunda, Lake Bonney 1, and Wattle Point) started operating like Semi-Scheduled units (so one reset on the measurement of ‘Market Demand’).
(b)  others (like Cathedral Rocks, Mt Millar and Starfish Hill) changed their mode of operations from 1st February 2022 (so another reset on the measurement of ‘Market Demand’).

Beginning 2023 the ‘lowest in ordinary times’ point had been at 16th October 2022 (61MW for ‘Market Demand’ and 100MW for ‘Operational Demand’).

Into 2023, they had subsequently dropped:

1)  On 16th Sept 2023;

2)  Then on 23rd Sept 2023;

3)  Then on 1st Oct 2023;

4)  Then today (31st Dec 2023).

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 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

—

Still to be filled in!

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 ‘Market 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 ‘Market Demand’ was 543MW).

It’s difficult to know what’s ‘ordinary’ and what’s ‘extra-ordinary’ about particular demand outcomes in Tasmania, and I’ve not had time to evaluate in detail.

So leaving this empty for now ….