Interconnector Watch: Monday 20 July 2026

Interconnector flows across the NEM are unconstrained at 10:30 AEST, with no binding limits reported despite significant loading on the Tasmania-Victoria and Victoria-NSW links. Basslink (T-V-MNSP1) is exporting 408 MW from TAS1 to VIC1, sitting at 89% of its 456 MW export limit — the tightest utilisation on the network — as Tasmania's 95.18 $/MWh price sits below VIC1's 105.88 $/MWh, consistent with the northward flow. VIC1-NSW1 is carrying 322 MW into NSW1, aligning with NSW1's higher price (112.78 $/MWh) relative to VIC1, while QNI (NSW1-QLD1) shows a larger 989 MW flow from QLD1 into NSW1, reflecting QLD1's discount at 95.84 $/MWh against NSW1.

In SA, Heywood (V-SA) is exporting 372 MW from VIC1 to SA1 at 68% of its 548 MW export limit, and Murraylink (V-S-MNSP1) adds a further 54 MW in the same direction, together supporting SA1's price of 113.34 $/MWh — currently the highest in the mainland NEM. Directlink (N-Q-MNSP1) is flowing 41 MW from QLD1 to NSW1, a modest contribution against QNI's much larger transfer on the same corridor. None of today's flows are approaching their respective import/export limits closely enough to bind, and mainland regional price spreads (QLD1 to SA1: ~17.50 $/MWh) remain narrow, indicating the interconnector network is comfortably managing today's demand profile (NSW1 9,551 MW, VIC1 6,612 MW, QLD1 6,736 MW, SA1 1,563 MW, TAS1 1,214 MW).

On constraints, the active notice of note is the Heywood-linked S-TBCP1 set, invoked following the short-notice outage of the Tailem Bend 275kV capacitor bank in SA on 18 July — this remains in force and applies to V-SA, though it is not currently binding given today's flow sits well within limits. Basslink-related contingency reclassifications tied to Tasmanian lightning events (Gordon-Chapel St and Farrell-Reece 220kV lines, Sheffield-George Town) have all been cancel