Interconnector Watch: Wednesday 10 June 2026

Three of six NEM interconnectors are binding at the 06:30 AEST dispatch interval, and the pattern is consistent: power is moving from lower-priced to higher-priced regions across the board, with constraints preventing those spreads from closing further. QNI (NSW1-QLD1) is at its import limit of 590 MW, carrying that full volume northward from NSW into Queensland — yet QLD sits at $111.11/MWh against NSW's $176.80/MWh. The binding import constraint on QNI is preventing additional southward arbitrage flow that would otherwise narrow that $65.69/MWh spread. On the VIC-NSW interconnector, 584.45 MW is flowing south from NSW into Victoria, close to but not at its import limit of 621.37 MW, so VIC-NSW is currently unbound with a small margin remaining. Victoria's price of $187.33/MWh sits $10.53/MWh above NSW, consistent with net imports into Victoria.

The Heywood interconnector (V-SA) is exporting at its binding export limit of 214.54 MW from Victoria into South Australia, which is priced at $192.90/MWh — $5.57/MWh above Victoria. With V-SA bound at its export cap, SA cannot draw further from Victoria, and the residual spread reflects that transmission ceiling rather than any generation scarcity unique to the region. Murraylink (V-S-MNSP1) is carrying zero flow with both import and export limits at zero, effectively out of service and contributing nothing to the VIC-SA corridor — this aligns with the active Kerang-Koorangie 220 kV unplanned outage constraint (V-KGKO, invoked 13:30 AEST 9 June), which has equations bearing on V-S-MNSP1, T-V-MNSP1, V-SA, and VIC1-NSW1 simultaneously and remains active today.

Basslink (T-V-MNSP1) is carrying 246.21 MW from Tasmania into Victoria, well within its export limit of 452.7 MW and unbound. However, the active notice for the APD A2 500/220 kV transformer outage in Victoria (constraint set F-I_ML_APD_LOAD, invoked 15:15 AEST 10 June) bears on Basslink's LHS, and that constraint set remains active this morning, meaning Basslink's effective ceiling may be tighter than the nominal export limit implies — traders should treat the 452.7 MW figure as a theoretical upper bound rather than available headroom. Tasmania's $153.51/MWh is $33.82/MWh below Victoria, consistent with Basslink moving energy northward to capture the spread.

In aggregate, three binding constraints — QNI at its import limit, Heywood at its export limit, and N-Q-MNSP1 near its import limit at 153 MW against a cap of 160.6 MW — are structurally preventing regional price convergence today. The Kerang-Koorangie and APD transformer outage notices remain active across multiple Victorian interconnector equations, compressing transfer capability through the Victorian network simultaneously. With Murraylink offline and Heywood capped, SA's $192.90/MWh is entirely dependent on the single Heywood circuit for interstate support. Any further derating of that corridor, or an unplanned trip