Mainland Frequency dragged downwards around sunset, on Sunday 30th November 2025
This late afternoon weakness in system frequency (on Sunday 30th November 2025) seems noteworthy.
Eventful days in 2025
A catalogue of articles pertaining to eventful days in 2025
AEMO releases ‘2025 Transition Plan for System Security’
On Monday 1st December 2025 (after it was flagged in some media articles) the AEMO released its 154-page '2025 Transition Plan for System Security'.
One example of why some batteries were charging during price spikes over the past couple of days in NSW
This article looks at the N::N_CNLT_2 transient stability constraint on Tuesday to give an example of why some NSW batteries ended up charging through Tuesday’s price spike.
A look at mainland grid frequency yesterday, November 26th, 2025
A quick look at the data from our frequency logger yesterday, showing the changes in frequency during the period of market volatility.
Unpacking some of the drivers of volatility in NSW today, on Wednesday 26th Nov 2025
Today in NSW we saw large price spreads, material network curtailment, wild swings in demand, and several other factors unfold. This article summarises some of the high-level drivers of today's events.
Daytime price volatility in NSW on November 26th, 2025
A quick snapshot of regional prices, where the spot price in NSW hit the MPC at 11:00am NEM time.
Further thoughts (and questions) about Waratah BESS, two weeks after the snowball started to roll…
Identifying 5 distinct time periods (from 26th Sept 2025 to 21st Nov 2025) with Waratah BESS, we take ez2view and some external references to try to piece together sequence of events in 3 of...
*Several* price spikes in NSW on Friday morning 21st November 2025 (including large jump in ‘Market Demand’)
A quick article with this NEMwatch snapshot at 08:35 (NEM time) on Friday 21st November 2025 to record some volatility in NSW.
Large drop in ‘Market Demand’ in South Australia on Thursday 20th November 2025
A quick note on Thursday evening 20th November 2025 to record this large size (214MW) drop in ‘Market Demand’ in the 17:50 dispatch interval NEM time this evening.
Early afternoon volatility in NSW on Thursday 20th November 2025
We’re busy focused on other things at present, so just a NEMwatch snapshot at 13:25 (NEM time) on Thursday 20th November 2025 to mark some volatility in the NSW region.
AEMO issues Market Notice ‘Update to Negative Settlement Residue constraint equations’
On Wednesday 19th November 2025, the AEMO issued MN130792 at 15:36 about "Update to Negative Settlement Residue constraint equations"
How high did frequency get, on Tuesday 11th November 2025, when that gremlin re-appeared?
Extracted our high(er) speed readings highlights that the mainland frequency exceeded the NOFB for a period of the morning on Tuesday 11th November 2025.
The bottom falls out of SA ‘Market Demand’ unexpectedly, on Tuesday 18th November 2025
A brief record of some challenges encountered in forecasting midday Market Demand for South Australia on Tuesday 18th November 2025.
Drops in mainland frequency on Saturday afternoon 15th November 2025
I’m not sure if related to the severe weather warnings for both QLD and NSW today, but here’s a quick record of some afternoon weakness in frequency control on Saturday 15th November 2025.
(A first?) Severe Weather alert for the Queensland (and now NSW) Region … Saturday 15th November 2025
Relatively early in the afternoon (Saturday 15th November 2025) I received simultaneous alerts from the BOM and from AEMO about 'severe weather' in relation to Queensland this afternoon.
Expected RTS for Yallourn 2 slips a month – now offline until 24th January 2026
On Friday 14th November 2025, the expected return to service for YWPS2 was pushed back another ~6 weeks (now offline till Monday 24th January 2026).
AEMO frequency monitoring report provides some details of frequency event (due to self-forecast glitch) on 19th August 2025
Adding to the list of articles we've collated about the frequency disturbance on Tuesday 19th August 2025, we're copying in what AEMO published in its 2025 Q3 monitoring report about the glitch.
Trying to understand the errors in ‘Initial Supply’ (on Tue 11th and Thu 6th November) as the source of the gremlins
In this article we take another step in trying to understand the source of the gremlins (on Thu 6th Nov 2025 and Tue 11th Nov 2025) that seemed to infect the dispatch process -...
AEMO (and the BOM) warning about possible ‘Severe Space Weather’ (at G4, possible G5) in next ~24 hours
One WattClarity reader has pointed us to AEMO and BOM warnings about space weather - noting that 'G4 geomagnetic storm conditions are currently being observed. G4 with a chance for G5 is expected on...
AEMO directs again in South Australia for Minimum System Load – Wednesday 12th November 2025 (second day in a row)
For the second day in a row, AEMO has issued direction (to Torrens Island BESS) due to concerns about Minimum System Load in South Australia - with today's on Wednesday 12th November 2025.