I’ve taken the opportunity of a quiet space to extract some data over a 4-hour time range (and at 0.1 second cadence) to compile the following trend:
Unfortunately:
our ‘Device 2’ location was temporarily offline (following some power outages following Brisbane storms at the time)
so we had to revert back to the new ‘Device 1’ location … which (as noted on the image) we have observed appears to suffer from occasional noise (perhaps related to local intermittent power quality issues?).
So in the chart above we can’t really trust the specific details of the depth of the frequency drop, other than to note that the low point will have been around ~17:01 (NEM time) on Thursday 30th October 2025.
That should be enough for us to explore in a bit more detail….
Paul was one of the founders of Global-Roam in February 2000. He is currently the CEO of the company and the principal author of WattClarity. Writing for WattClarity has become a natural extension of his work in understanding the electricity market, enabling him to lead the team in developing better software for clients.
Before co-founding the company, Paul worked as a Mechanical Engineer for the Queensland Electricity Commission in the early 1990s. He also gained international experience in Japan, the United States, Canada, the UK, and Argentina as part of his ES Cornwall Memorial Scholarship.
Yesterday afternoon, we quickly noted the ‘Frequency drop on Friday afternoon 31st October 2025’. Now, we take a closer look to highlight the lowest point (outside of the NOFB).
It appears that there was some large(ish) trip in demand somewhere on the Queensland network, given the spike in frequency at ~07:28 on Tuesday 14th October 2025.
With All Energy happening this week in Melbourne, plus the clock ticking down on preparations at the Nelson Review Panel for their final report, I’ve reached back to the NEMdev conference to write about 2 big concerns with the draft Recommendations 2A and 2B.
1 Commenton "A second look at the frequency drop on Thursday evening 30th October 2025"
Here’s the raw hz data from Melbourne. 49.84hz is the lowest I saw
https://www.dropbox.com/scl/fi/x1t4c6wku2fw6dt21c2m0/hz-data.csv?rlkey=vz5w7ppo8m8umf1md09jrelxw&dl=0 (note it also has noise but