Brief but sudden drop of ~1,740 MW of wind and solar generation across the NEM this afternoon Monday 5th December 2022

An automated ez2view email alert this afternoon drew my attention to a sudden loss of 630MW of generation in SA at around 2:55PM NEM Time (UTC+10).

After a very quick investigation, I can see that output dropped for a number of wind and solar farms across the NEM. My quick maths shows a drop of 1,470MW of wind generation in the mainland regions between the 14:50 and 14:55 dispatch intervals, primarily within SA and VIC. The output of large solar generators in the mainland regions also dipped by 270MW for the same dispatch interval.

The screenshot below shows schematics of the SA and VIC regions before and after the sudden drop in generation.

Schematics of the SA and VIC regions during the 14:50 dispatch interval – directly before the sudden drop in generation.

Source: ez2view Regional Schematics widget

Schematics of the SA and VIC regions during the 14:55 dispatch interval – showing the sudden drop in output for a number of stations.

Source: ez2view Regional Schematics widget

Output at many of the affected generators returned to typical levels by the 15:15 dispatch interval. Prices also moved at 14:55 with the dispatch price in SA and VIC hitting -$1,000.00 and -$925.40 respectively, before quickly bouncing.

Edit on the 6th December 2022:

With the benefit of next-day bid data, it looks like TUMUT3 rebid it’s volume as negative for this interval and as a result, it’s output rose by 1,491MW. The unit also appears with a positive factor on the left-hand side of the N>>AVMA-17_39_11 constraint which bound during the 14:55 interval.

Source: ez2view Unit Dashboard widget