No sooner had we hit <PUBLISH> on the article ‘‘Market Demand’ in Victoria ramps by 903MW in 10 minutes, on Monday 9th December 2024’ than we see an even larger, and faster, ramp down in ‘Market Demand’ in Victoria, as captured in this snapshot from NEMwatch at 14:45:
No, your eyes are not betraying you (I had to look twice myself) … that’s:
1) A drop from 5,518MW (at 14:40) to be 2,418MW (at 14:45);
2) Or a drop of 3,100MW in 5 minutes
… which surely could not be real – especially given that frequency has been (sort of) stable around 50Hz … notwithstanding the recent emergence of the 49.95 to 50.05Hz deadband that Linton discussed earlier, as we see here:
I’m guessing this is some new gremlin in the AEMO data systems?
It looks like there might be some issues with VNI flows since the Initial MWs were following exactly the same as Target MWs from 13:35 to 14:40.
Perhaps, AEMO has lost visibility of actual VNI flow reading, and NEMDE only could calculate combined demand of NSW and VIC but not individually.
With Initial being the same as Target, NEMDE saw/used the flow into VIC increasing = NSW demand decreasing and VIC demand increasing. The correct Initial value seemed to have come back at 14:45 with the NSW and VIC demand corrected.