Interconnector Watch

SA1 at $138/MWh is the standout price in the NEM this interval, and the two Victoria-to-SA interconnectors explain why. Heywood (V-SA) is exporting 599.66 MW into SA — precisely at its export limit of 599.66 MW and binding. Murraylink (V-S-MNSP1) is simultaneously binding at its 65 MW export cap, also flowing Victoria to SA. Together the two links are pushing every available MW west, yet SA still clears $22/MWh above Victoria ($115.68/MWh), confirming that interconnector capacity — not willingness to trade — is the binding constraint on the SA price spread. With both links fully loaded, there is no headroom to arbitrage that differential away during this interval.

Across the Queensland-NSW border, QNI (NSW1-QLD1) carries 76.87 MW southbound from QLD into NSW, sitting at roughly 50% of its effective export limit in this direction. The link is not binding, and the $1/MWh price gap between QLD ($120.52/MWh) and NSW ($119.49/MWh) reflects that — marginal price convergence is largely achieved across this corridor right now. The DC Murraylink equivalent for the Queensland border, N-Q-MNSP1, sits at zero flow with capacity available in both directions, contributing nothing to arbitrage this interval. Note that a negative settlement residue constraint (NRM_QLD1_NSW1) was active on QNI earlier yesterday but was cancelled at 16:15 AEST; it is not operating this interval, so no residue management action is currently restricting that corridor.

On the VIC-NSW corridor, VIC1-NSW1 carries 91 MW northbound from Victoria into NSW — roughly 57% of its available import capacity from that direction. The link is not binding, and the modest $4/MWh NSW-VIC spread is consistent with a partially utilised interconnector providing reasonable price convergence between the two largest regions. Basslink (T-V-MNSP1) exports 92.06 MW from Tasmania into Victoria, at around 37% of its 245.7 MW export limit. The link is not binding and Tasmania's $88.16/MWh — the lowest price in the NEM — reflects that Tas generation is moving north at a discount to Victoria but the corridor is not fully loaded. The series of Tasmanian lightning-related N-2 contingency reclassifications that constrained Basslink's export capability across 10–13 April have now been fully resolved, with constraint sets T-JB_MC_TI_250 and F-T-JB_MC_TI_N-2 revoked at 06:25 AEST today. Basslink is operating without those overlays.

In summary, the only active binding constraints today are on the SA corridors — both Heywood and Murraylink are at their export limits — and these directly sustain SA's $22–23/MWh premium over Victoria. All other interconnectors have available headroom and are producing reasonable regional price convergence. The Tasmanian network is clear of the contingency constraints that complicated Basslink scheduling across the past three days, restoring normal operating conditions on that link.