Wobbles at Yallourn unit 4
A brief look at recent operational challenges at Yallourn unit 4.
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Highlighting particular (frequency and/or AggROT) events through 2024 and 2025
In this article, we tie together various events since 1st January 2024 that featured either System Frequency outside the NOFB and large AggROT for Semi-Scheduled assets.
Outage at Vales Point unit 5 extended – return to service now not expected until 15th December 2025
Subsequent to earlier article about VP5, the expected duration of the outage pushed out by more than a month.
AEMO notes ‘New Victorian system normal constraint to manage contingency size on north-west Victoria’
The AEMO notifies that the new 'V_NWVIC_GFT1_750' constraint equation will first be invoked from 10L00 on Tuesday 9th September 2025.
Vales Point unit 5 (partly unplanned) outage – return to service currently expected 9th November 2025
On Tuesday 26th August 2025 the VP5 unit came offline, with rebid reasons suggesting that ‘turbine vibrations’ were a factor. We take a look ~10 days later.
Daily NOFB exceedances since 2021
We count the number of days each month when there was at least one 4-second measurement outside the NOFB.
AEMC releases July 2024 working paper ‘Addressing the risk of algorithmic collusion’
Today we were alerted that the AEMC had belatedly published this 15-page Staff Working Paper titled ‘Addressing the risk of algorithmic collusion’.
AEMO initiates new operational requirements in SA (1 synchronous unit, in certain circumstances) and NSW (system strength)
Worth a short note today (Wednesday 3rd September 2025) to record AEMO’s Market Notice 128912 published at 16:10
Instances of system frequency outside the normal operating band
How common is it that mainland frequency deviates outside the NOFB (normal operating frequency band)?
(Two not one!) more media article (and 5, not 4, analysts) questioning Eraring’s mooted closure in 2027 … and same for other coal units
It was no surprise at all to open the AFR and see 4 different analysts quoted in voicing their concerns about the unrealistic notion that Eraring can close...
Yes, Tamar Valley CCGT did switch off last week (on Wednesday 27th August 2025)
Looking back to Wednesday 27th August 2025, when Tamar Valley CCGT switched off.
Looking more at (commissioning) operations at Waratah BESS through August 2025
In this article we take a look at operations of Waratah BESS through August 2025 - including some large Dispatch Errors on several days: (a) including Fri 29th...
More about that decay of mainland frequency at lunchtime on Friday 29th August 2025 (i.e. Part 2)
Taking a second look at the midday decay of mainland frequency on Friday 29th August 2025.
Mainland frequency drop with Loy Yang A1 trip on Saturday evening 30th August 2025
On Saturday evening 30th August 2025 there was a trip (and then subsequent recovery) of the Loy Yang A1 unit - we take a look at frequency change.
Queensland’s minimum ‘Market Demand’ point drops lower still, on Sunday 31st August 2025
Worth a quick note with a NEMwatch snapshot at 10:35 (NEM time) on Sunday 31st August 2025 to mark the ‘lowest ever*’ point for ‘Market Demand’ nudging lower...
Unplanned outage on Yallourn Unit 2 extended another ~month (with new RTS expectation 22nd October 2025)
As a further update on outage expectation for the damaged YWPS2 (which tripped with 'LP turbine issue' on Tue 26th August) the latest return to service expectation is...
Decay of mainland frequency at lunchtime on Friday 29th August 2025
As another case of frequency disruption on the mainland grid, we spotted this trend occurring just before midday on Friday 29th August 2025.
Today’s Presentation at the CSIRO and DFAT’s System Planning Workshop
A short post to note our presentation for the CSIRO's South-East Asian System Planning Workshop in Brisbane this afternoon, and the analysis we shared.
Unplanned outage on Yallourn Unit 2 pushed out ~2 weeks (with new RTS Thursday 25th September 2025)
An updated look (as at 14:10 on Thu 28th Aug 2025) of expected return to service for YWPS2
Tasmanian demand drop on 16 August 2025 – part 2
We follow on from A 292MW drop in "Market Demand" in Tasmania, on Saturday 16th August 2025 enlisting this "Part 2" to understand the sequence of events using 4-second...