I’ve not been posting about this type of frequency disruption in recent months (focused elsewhere) but worth a short note because of a 295MW drop in output from Loy Yang A3 just prior to 14:06 (NEM time) on Tuesday 20th May 2025:
Here’s a quick look at the live frequency trace for the mainland over the past hour:
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).
I’ve not yet had time to fully investigate, but thought it worth recording the sharp drop in frequency that appears to have occurred shortly after 07:30 NEM time on Friday 13th June 2025.
Following the notice from AGL Energy on Friday last week about the extended outage occurring at Loy Yang A unit 2, here’s some initial thoughts via WattClarity (with more to come as time permits)
1 Commenton "Loy Yang A3 offline on Tuesday afternoon 20th May 2025 – small frequency drop"
If the NEM at the time was about 21GW then yes, the bump is about right for the loss of 300MW odd. Interesting the relatively slow recovery. Must be about the deadband setting. I thought the magic batteries were bidding in for small signal raise????
If the NEM at the time was about 21GW then yes, the bump is about right for the loss of 300MW odd. Interesting the relatively slow recovery. Must be about the deadband setting. I thought the magic batteries were bidding in for small signal raise????