A collation of articles pertaining to Tuesday 19th August 2025.
On this day …
1) We saw some other things happen, including those in this broader category focused on the day.
2) But in this category we’ll collate articles specifically about the large frequency spike across the NEM
(a) lasting ~25 minutes
(b) and above the upper bound of the Normal Operating Frequency Band in the middle of the day.
The (concerning) frequency spike across the NEM in the middle of the day (Tuesday 19th August 2025) has triggered many proximate questions - understandable - but also has raised these 3 Broader Questions.
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.
On Tuesday the 19th of August between 11:45 and 12:20 there was a significant frequency deviation on the mainland.