Sharp mainland frequency drop, with trip of CPP_4 on Sunday evening 26th October 2025
The Callide C4 unit tripped from 420MW in the 5 minutes to 18:36 (NEM time) on Sunday evening 26th October 2025, delivering a sharp drop in mainland frequency.
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Two *big concerns* that we urge the Nelson Review panel to (re)consider (with respect to Invisible Responses) following review of the Draft Report
With All Energy happening this week in Melbourne, plus the clock ticking down on preparations at the Nelson Review Panel for their final report, I've reached back to...
Selected 4-second data relating to the (SemiSched-induced) frequency weakness on Thursday 16th October 2025 (i.e. Part 4)
In Part 4 of this evolving Case Study, we take a closer look (using 4-second data) at the 12 x offending Semi-Scheduled units that appear to have played...
AEMO announces that it’s ‘progressing transitional system security services’
A quick note to point readers here to the AEMO news update ‘AEMO progressing transitional system security services’ published today (Friday 24th October 2025).
A hot afternoon in NSW on Wednesday 22nd October 2025 (but the price did not pop … at least to 14:15)
A short article looking at the NSW region in early afternoon Wednesday 22nd October 2025.
WeatherWatch notes ‘Cyclonic Conditions for Victoria, Widespread Gales Across NSW & Areas of South Australia’
A short note (on Wednesday morning 22nd October 2025) about the Severe Weather warnings (from WeatherWatch, and then from AEMO).
Taking a first focused look at the 16:50 dispatch interval on Thursday 16th October 2025 (with frequency dropped below NOFB) … Part 3
In Part 3 of this series with respect to Thursday 16th October 2025, we focus on when a large collective under-performance across all Semi-Scheduled Wind Farms and Solar...
Unplanned outage of Dapto – Marulan (8) 330 kV line
At 07:55 (on Monday 20th October 2025), an unplanned outage of Dapto - Marulan (8) 330 kV line led to the unplanned invocation of the 'N-DTMN_8_15M' constraint set.
Spicy prices forecast for NSW on Monday afternoon/evening 20th October 2025
A quick note, on Monday morning 20th October 2025, showing the re-emergence of price forecasts up near the Market Price Cap for a 90-120 minute period this afternoon/evening.
Forecast Minimum System Load for Victoria next Saturday 25th October 2025
A short note to flag MN129813 looking forward to next Saturday 25th October 2025, flagging possible MSL1 in Victoria.
Considerable uncertainty, with respect to what might unfold in NSW next Wednesday 22nd October 2025
Following a series of Market Notices from AEMO with respect to forecast LORx conditions for NSW next Wednesday 22nd October 2025, we take a first look.
Price spike in NSW (and QLD!) at 14:55 on Friday 17th October 2025
A very quick article to record the price spike (for ENERGY) in the NSW region at 14:55 earlier today (Friday 17th October 2025) ... and Contingency Lower in...
How the NEM BESS fleet is operating on peak days, and how to be a savvy operator
In this guest article, Matt Grover from Fluence draws on operational data and real-world trading experience to unpack how Australia’s grid-scale batteries performed across three June 2025 peak...
Peeling the second layer of the onion, with respect to the (SemiSched-induced) frequency weakness on Thursday 16th October 2025
Having already noted the ‘Weakness in frequency stability on Thursday afternoon 16th October 2025’, we take a look at the causes - for the four high-profile dispatch intervals.
Aldoga Solar Farm on Sunday 12th October 2025 – Part 2
In this article we inspect power deviations from dispatched units that would have contributed to the frequency rise, and the deviations that would have contributed to the correction.
Weakness in frequency stability on Thursday afternoon 16th October 2025
The worst periods of frequency stability on Thursday 16th October 2025 were *not* with the simultaneous trip of YWPS3 and YWPS4, but rather later and the day -...
Both YWPS3 and YWPS4 back online overnight
A quick follow-on early Friday morning 17th October 2025 to note that both YWPS3 and YWPS4 made it back online overnight.
Differing return to service expectations for YWPS3 and YWPS4, following simultaneous trips
Following the simultaneous trips (on Thu 16th Oct 2025) of YWPS3 and YWPS4, we take a look at current return to service expectations.
System frequency during simultaneous trips at YWPS3 and YWPS4 on Thursday 16th October 2025
System frequency remained within the NOFB, appears well managed given the supply loss approached 600 MW.
After Yallourn units trip, AEMO again issues directions to Jeeralang Power Station, for System Strength in Victoria
Following the simultaneous trip of units at Yallourn, directions to Jeeralang Power Station were issued for maintaining System Strength in Victoria.