A quick initial look (via ‘Dispatch Error’) at the Demand and Frequency drop on Wednesday afternoon 5th August 2026
A first look at yesterday's major frequency event (and demand gyration in NSW) using 'next day public' data to look at Dispatch Error
Operational Glitches
‘Scheduling Error’ also declared in relation to glitch(es) on 6th and 11th November 2025
On Friday 29th May 2026, the AEMO alsodeclared Scheduling Errors (together anointed number 76), with respect to the joint glitches on Thu 6th Nov 2025 and Tue 11th Nov 2025.
AEMO declares ‘Scheduling Error’ in relation to glitches on Friday 10th April and Saturday 11th April 2026
Given prior analysis we'd written and published about two recent glitches (Fri 10th April and Sat 11th April 2026) it was not really a surprise, though it’s nice to know, that the AEMO declared both Scheduling Errors.
AEMO incident report released, on Frequency Spike due to Self-Forecast Vendor glitch (19th August 2025)
About the AEMO’s Reviewable Operating Incident Report ‘Self-forecasting errors and frequency excursion on 19 August 2025’.
402 different stories – Semi-Sched units during both frequency spikes (Fri 10th and Sat 11th April 2026)
We start with this unbundled listing of 402 discrete stories about the performance of Semi-Scheduled units (115 solar & 86 wind) units on Friday 10th and Saturday 11th April with the frequency spikes.
One image to summarise the sequence of events in the Frequency Spikes of Fri 10th and Sat 11th April 2026
Presenting this single image which summarises the sequence of events (for a number of Semi-Scheduled units) over three dispatch intervals across the pair of frequency spikes (on Fri 10th and Sat 11th April 2026).
A big clue to one causal factor in both frequency spikes (on Friday 10th April 2026 and Saturday 11th April 2026)
Next layer of the onion, in investigating the eerily similar (and closely related) frequency spikes outside the NOFB on Friday 10th April 2026 and Saturday 11th April 2026.
Across 201 x Semi-Scheduled units, which were the biggest over-performers (Saturday afternoon 11th April) driving the frequency high?
With the advantage of 'next day public' data we look at 'Dispatch Error' (for all 201 Semi-Scheduled units) at 14:20 on Saturday 11th April 2026 to see what drove the frequency spike outside of the NOFB. There was a big imbalance...
A very similar spike in frequency (outside the NOFB) on Saturday 11th April 2026
A first look at a frequency spike (outside the NOFB) focused in the 14:20 (excursion) and 14:25 (recovery) dispatch intervals NEM time on Saturday 11th April 2026 (an almost identical event to what happened the day before).
Another case of Semi-Scheduled VRE over-production (this time at 14:20 on Saturday 11th April 2026)
We've already written about the collective over-performance of Semi-Scheduled VRE on Friday 10th April at 10:30 driving frequency high. There was also an incident at 14:20 on Saturday 11th April 2026 worth investigating ...
Yes, it was a large over-performance from Wind Farms (many of them) that drove frequency above the NOFB on Friday 10th April 2026
With the advantage of 'next day public' data we look at 'Dispatch Error' at 10:30 and 10:35 on Friday 10th April 2026 to see what drove the frequency spike outside of the NOFB.
Four big Non-Conformances at Wind Farms (coincidentally on Friday 10th April 2026 at the time of the frequency spike). Some gremlin in the works?
Occurring just after the frequency spike on Friday 10th April 2026 were these 4 large Non-Conformances noted at 4 x Wind Farms in Victoria.
The curious case of a frequency spike (outside of the NOFB) on Friday 10th April 2026
A first look at a frequency spike (outside the NOFB) focused in the 10:30 (excursion) and 10:35 (recovery) dispatch intervals NEM time on Friday 10th April 2026.
AEMO releases preliminary report into NSW market suspension on the 23rd March 2026
The AEMO has published its preliminary report into the suspension of the NSW spot market on 23 March 2026 — an event triggered by a SCADA-related issue that interrupted normal dispatch and pricing processes.
Mixed sources of semi-scheduled availability on March 23, 2026
We use a chart to see how semi-scheduled unit availabilities changed their origin. With interruptions to SCADA across NSW, many of the inputs that an availability forecast depends on could have been impacted.
A quick introduction to the gyrations on the ‘N>>NIL_060_051’ Constraint Equation during NSW Market Suspension
A short (and somewhat cryptic) post about the ‘N>>NIL_060_051’ constraint equation during NSW Market Suspension on Monday 23rd March 2026.
Managing bids during the market suspension on 23 March 2026
One feature of a market suspension is the possibility for suspension pricing, which happened in this case. Did it influence energy offers?
Initial energy storage involved in issues
Energy storage levels of NSW grid scale batteries are analysed for behaviour on 23 March 2026.
AEMO ends Market Suspension in NSW from 18:30 Monday 23rd March 2026
A short note to follow the earlier note about MN135948 with the MN136023 published at 17:54:22 about Market Resumption
System frequency while NSW demand yo-yos
Following our observations of "Riding the yo-yo, during NSW market suspension" we inspect system frequency during the day.