Market Notices

AEMO ELECTRICITY MARKET NOTICE

AEMO will increase the Heywood test limit from SA to Vic (from the current 550 MW) to 600 MW today to conduct internetwork testing on Heywood.

The following constraint sets will be revoked once the testing criteria met:
I-SV_HEY_550_TEST

The following constraint sets will be invoked:
I-SV_HEY_600_TEST

AEMO will revert the Heywood test limit back to 550 MW once the test has completed while the test result being analysed.

Please also refer to the published formal PEC Stage 1 and HIC capacity release testing information at the following link: https://aemo.com.au/-/media/files/stakeholder_consultation/consultations/nem-consultations/2023/project-energyconnect-stage-1-and-hic-capacity-release/pec-stage-1-and-hic---final-test-program.pdf?la=en.

Terry Liu
AEMO Operations

AEMO ELECTRICITY MARKET NOTICE

Issued by Australian Energy Market Operator Ltd at 2000 hrs on 1 June 2026

CANCELLATION - ACTUAL NEGATIVE SETTLEMENT RESIDUES - VIC to NSW - 1 June 2026.

Refer to market notice: 144181

AEMO has ceased taking action to minimize the further accumulation of negative settlement residues on the VIC to NSW directional interconnector.

The negative residue constraint NRM_VIC1_NSW1 ceased operating at 2000 hrs on 1 June 2026.

This is an AEMO autogenerated Market Notice.

AEMO ELECTRICITY MARKET NOTICE

Issued by Australian Energy Market Operator Ltd at 1820 hrs on 1 June 2026

ACTUAL NEGATIVE SETTLEMENT RESIDUES - VIC to NSW - 1 June 2026.

Electricity Market outcomes have resulted in the accumulation of negative settlement residues that have exceeded the allowable negative residue threshold for the VIC to NSW directional interconnector.

The negative residue constraint set NRM_VIC1_NSW1 commenced operating from 1820 hrs on 1 June 2026.

This constraint set contains an equation with the following interconnectors on the LHS:
VIC1-NSW1

The RHS of the constraint equation may be adjusted to manage residues.


This is an AEMO autogenerated Market Notice.

Refer to Market Notice 134696

AEMO has now completed the production of the Murraylink dynamic rating forecast model and the forecasting performance has been satisfactory during the test. AEMO will be enabling the pre-dispatch and PASA formulation using the Murraylink dynamic rating forecast on the following two constraint equations at 1000 hrs on Wednesday 27th May 2026.

VSML_RAT_LIM_DYN
SVML_RAT_LIM_DYN

For full details on the formulation, the updated constraint equations have now been loaded into AEMO's pre-production systems.

Terry Liu
AEMO Operations

VicGrid has conducted studies and determined that the maximum generation contingency size in Victoria can be increased from 600 MW to 750 MW.

This change affects the generator limitations for prior outage conditions especially in the South-west Victoria area. The new generation limitation for outages is now 750 MW. AEMO has implemented this change in production on 13th May 2026 by updating generation constraints to increase the generation upper limits for outage conditions.

Please refer to the Network Outage Schedule for any upcoming outages in south-west Victoria here.
https://www.aemo.com.au/energy-systems/electricity/national-electricity-market-nem/data-nem/network-data/network-outage-schedule

For further details on this change please refer to VicGrid Limits Advice or contact VicGrid.
vicgrid.com.au/transmission-planning/planning-the-energy-grid

Terry Liu
AEMO Operations

AEMO ELECTRICITY MARKET NOTICE

A network augmentation has been commissioned in the NSW Region.

At 1740 hrs the following equipment was commissioned.

Wagga - Dinawan 6L 330 kV Line
Wagga - Dinawan 6J 330 kV Line
Dinawan 330 kV A and B Buses

Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE

Following a review of the operation of the Very Fast FCAS market, from 5th May 2026 AEMO will increase the cap on dispatch of Very Fast Contingency FCAS in the QLD region from 200 MW to 250 MW, during periods where islanding of the QLD region is considered credible.

No other changes to the dispatch of Very Fast FCAS or FCAS constraint equations will be made on this date.

For more information on the Fast Frequency Response (FFR) initiative, please visit:
https://www.aemo.com.au/initiatives/major-programs/fast-frequency-response

AEMO Operations

AEMO ELECTRICITY MARKET NOTICE.

Update - Lightning vulnerable lines in Tas region

Refer to AEMO Electricity Market Notice 141036

At 1357hrs 11/04/2026 the Farrell -Tribute 220 kV line and Farrell - John Butters 220kV Line tripped.

The cause of the trip was identified as due to lightning.
In accordance with SO_OP_3715, AEMO now considers the Farrell -Tribute 220 kV line and the Farrell - John Butters 220kV line to be vulnerable with a category of probable due to lightning.

Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE

Issued by Australian Energy Market Operator Ltd at 1615 hrs on 13 April 2026

CANCELLATION - ACTUAL NEGATIVE SETTLEMENT RESIDUES - QLD to NSW - 13 April 2026.

Refer to market notice: 141054

AEMO has ceased taking action to minimize the further accumulation of negative settlement residues on the QLD to NSW directional interconnector.

The negative residue constraint NRM_QLD1_NSW1 ceased operating at 1615 hrs on 13 April 2026.

This is an AEMO autogenerated Market Notice.