Unit deviations from target on Tuesday 19th August 2025
It appears it was unit availability used to set the target for dispatch that went awry, rather than unit output.
It appears it was unit availability used to set the target for dispatch that went awry, rather than unit output.
Among other aspects, a large dip in solar UIGF aligns with the frequency deviation observed on 19th August 2025.
In reviewing system frequency on the 16th of June, 2025, we observed a drop that reached below the NOFB.
The measurements indicated frequency ducked just below the NOFB briefly, reaching 49.843 Hz.
At 16:01 on April 10, 2025, a system frequency dip was observed from the Global-Roam frequency logger.
The NEM operates at a frequency of 50 hertz (Hz) which means the alternating current should cycle 50 times a second between positive and negative voltage.
In this overview, we take a longitudinal look back at how frequency has changed over the years.
To further understand the frequency drop we delve into the 4-second data (used for regulation FCAS contribution calculations) in this Part 2, looking at generating units (including BDUs).
Grid frequency had dropped to 49.689 Hz. We take an initial look into the timeseries of grid frequency recorded on the day.
Allan O'Neil provides an explainer about how small deviations in supply and demand are managed in the NEM, in order to help us understand the apparent swings in frequency that we noted in QLD...
Paul McArdle recently drew my attention to a short Twitter thread started by David Osmond on the arcane topic of NEM system frequency behaviour: At Paul’s invitation I’ve dived further into this issue...
The National Electricity Market (NEM) is designed to operate at 50 Hz. Frequency deviation occurs when generation and load are mismatched. It is important in a lightly meshed and long network such as the...
Ancillary Services Matter! No longer just realm of electrical engineer or energy trading boffins, ancillary services (and particularly Frequency Control Ancillary Services or FCAS which will concentrate on today) have become front and centre...