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.
mainland
Instances of system frequency outside the normal operating band
How common is it that mainland frequency deviates outside the NOFB (normal operating frequency band)?
Mainland Frequency Spikes to 50.2 on Tue 19th August 2025
On Tuesday the 19th of August between 11:45 and 12:20 there was a significant frequency deviation on the mainland.
Frequency Performance Payments 44 days in
An initial review of payment and cost outcomes of the first 44 days of financial operation of the FPP arrangements.
Drop in mainland frequency on 16 June 2025
In reviewing system frequency on the 16th of June, 2025, we observed a drop that reached below the NOFB.
Mainland system frequency in the afternoon of April 10, 2025
At 16:01 on April 10, 2025, a system frequency dip was observed from the Global-Roam frequency logger.
Mainland system frequency on April 10, 2025, associated with VIC transmission outage
High speed frequency measurements provide a deeper understanding of how the system responded to the unplanned 500kV line outage.
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.