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
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.
Record intra-day price spread as the NSW spot price goes near the market floor, after hitting the market cap on Tuesday 25th Nov 2025
So far today we've seen a $21,019.65/MWh intra-day price spread in NSW, underscoring just how far prices can swing in the NEM.
Price spikes up to the MPC in NSW, seemingly out of the blue, during the middle of Tuesday, 25th Nov 2025
A brief but unexpected spike to the market cap in NSW in middle of today has prompted a closer look at the rapid demand jump, counter-price flows and binding constraints that shaped the outcome.
Energex report nearly 100,000 customers still without power this morning in South-East Queensland after last night’s storms
A fast-moving thunderstorm system swept through Brisbane and surrounding regions on Monday afternoon, bringing destructive winds, giant hail and more than 800,000 lightning strikes.
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.
A case study into reserve uncertainty during peak demand events in the NEM
A summary of a recent academic case study looking into the events of January 22, 2024 in the QLD region, revealing how DER dynamics, weather variability and forecast limitations are amplifying operational challenges.
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).