Interconnector Watch

VIC1-NSW1 (the VIC–NSW interconnector) is the sole binding constraint on the NEM at 06:30 AEST, flowing at exactly 639.77 MW northward from Victoria to New South Wales — sitting precisely at its export limit of 639.77 MW. This binding condition directly explains the $76.30/MWh price in NSW versus $0/MWh in VIC1: Victoria is generating surplus power that cannot move north beyond the current limit, suppressing the Victorian spot price to zero while NSW remains insulated at a materially higher level. Earlier this morning, AEMO activated a negative settlement residue constraint (NRM_NSW1_VIC1) on this interconnector from 19:00 AEST, then cancelled it at 19:45 AEST, indicating a brief period where flow economics were producing negative residues on the NSW direction — that constraint is no longer active, but the underlying price divergence persists with the export limit now the operative restriction.

QNI (NSW1-QLD1) carries 136.23 MW northward from NSW into Queensland, well within its 725.47 MW export limit at around 19% utilisation. With NSW at $76.30/MWh and QLD at $78.93/MWh the spread is narrow at $2.63/MWh, consistent with a relatively unconstrained, lightly loaded interconnector arbitraging a small price differential. Heywood (V-SA) is exporting 101.21 MW from Victoria into South Australia against a 426.56 MW export limit — roughly 24% utilised — and with SA1 also sitting at $0/MWh alongside VIC1, there is no meaningful price spread to arbitrage across that link right now. Murraylink (V-S-MNSP1) is similarly flowing 81 MW VIC-to-SA and is at its import limit of 81 MW, meaning it is effectively at capacity on the SA import side, though SA's $0/MWh price means the economic significance of that cap is limited at this interval.

Basslink (T-V-MNSP1) is flowing 58.48 MW from Victoria into Tasmania — that is, Tasmania is importing — at its export limit of -58.49 MW, so Basslink is also effectively at capacity in the TAS-import direction. Tasmania prices at $72.60/MWh against Victoria's $0/MWh, a spread of $72.60/MWh, which is consistent with the interconnector being constrained at capacity and unable to fully bridge that differential. Multiple lightning-related contingency reclassifications on Tasmanian 220 kV circuits — including the Farrell–Reece and Tungatinah–Waddamana lines — were invoked and subsequently cancelled over the past 24 hours. All those constraint sets are now revoked, and no binding TAS-related network constraints are currently active. The N-Q-MNSP1 (Directlink) is carrying a modest 17 MW northbound, well within its 73.87 MW export limit and not binding.

In summary, the dominant market dynamic this interval is the binding VIC1-NSW1 export limit, which locks in a $76.30/MWh NSW–VIC price spread and prevents additional Victorian supply from clearing higher-priced NSW demand. Basslink is also at its capacity limit importing into Tasmania, sustaining a $72.60/MWh TAS–VIC spread. All other