System frequency at 11 am in 2026, September update
The strongest alignment for a free power window-start is when Qld, Vic and NSW all start at 11am, between April and October.
Areas of deeper analysis
The boundary effect
NEM demand tragic and occasional WattClarity guest author Allan O'Neil drills into an apparent discrepancy in AEMO's demand calculations following the 1 July 2026 transition of the Basslink interconnector from MNSP market participant to Regulated status.
A down year: a review of Q2 2026 spot prices
This is the 2026 edition of our annual review into Q2 spot prices, where we find that average prices fell sharply in all NEM regions compared to Q2 2025, but more importantly, duration curves are changing shape.
Analytical Challenge – the Heis-energy-burger Uncertainty Principle*
Briefly describing another of the core Analytical Challenges we've seen (and experienced) over the years...
Still air, empty tanks and a hot joint
Guest author, Allan O'Neil, goes into some detail of exploring the various factors contributing to the price volatility in South Australia that bookended the night of Sunday 21th June into Monday 22nd June 2026.
System frequency at 11 am in 2026
By June the dip in frequency just after 11 am is clear.
Intraday price spreads thinned out in most regions over summer 2025–26
This short article looks at intraday 2-hour price spreads across the NEM over this past summer, showing that volatility thinned out in most regions compared with recent summers, with a major SA price event on the 26th of January proving an outlier.
Stress-testing the NEM
This article by Endgame Analytics explains why average or median forecasts are becoming increasingly inadequate, using multi-year weather and supply stress testing to expose the true distribution of outcomes, risks, and reliability challenges in a high-renewables power system.
Frequency performance payments 44 days in, part 2
Categories with a longer bar left of zero are losing more of their spot energy market revenue to regulation and PFR costs.
The trend continues: a review of Q2 2025 spot prices
For nearly a decade, we’ve published annual reviews of Q2 prices to highlight the growing volatility during this period. Here’s our latest edition, examining how Q2 2025 compared.
Today’s presentation to CEC’s Market & Grid Directorate
We thank the Clean Energy Council for the opportunity to share insights into revenue trends, cost trends, and analysis of upcoming changes for units operating in the NEM.
Three headline observations, about the use of proxies for System Frequency in Frequency Control mechanisms
Various authors have shared articles about frequency, frequency control and Regulation FCAS in recent times (including 6 from Linton). Here's three things that jumped out to me in these pieces of analysis.
Regulation prices and enablement – a historical review
The introduction of frequency performance payments in 2025 changes how costs of regulating frequency are quantified and allocated. This article inspects historical trends in regulation FCAS enablement levels and prices.
Comparing Frequency Measures (Frequency, FI, FM)
The faster-moving nature of the FM, with the introduction of FPP, removes predictability in the indicator for frequency performance.
NEMDE nightmares – parallel pathways and clashing constraints
Prompted by a question by a client in a training session for a new ez2view user, guest author Allan O'Neil has written 2,940 words to explain the price outcome in one particular dispatch interval for one particular region (19:05 on Tuesday 11th February 2025 in...
Some remarks on Victorian demand
Allan O'Neil takes a closer look at Victorian electricity demand on Sunday, February 2nd — which stood out as an unprecedented anomaly when looking at the history of weekend demand in the region.
PEC Stage 1 in operation – be careful what you wish for
Guest author Allan O'Neil looks at how operation of Project EnergyConnect Stage 1 may affect market outcomes, with some early indications that impacts won't be as straightforward as you might think.
Final Report from the Select Committee on Energy Planning and Regulation in Australia
On Friday 20th December 2024 we saw the release of the Final Report from the Select Committee on Energy Planning and Regulation in Australia, which has been run by the Australian Senate in recent months
Mainland grid frequency: cat ears and golf
It was captured by a keen eyed reader, that the distribution of mainland grid frequency in recent times now exhibits cat ears.
NEM Mainland frequency patterns – historical overview from 2024
In this overview, we take a longitudinal look back at how frequency has changed over the years.