Interconnector Watch: Tuesday 25 August 2026
Basslink is running hard at 345 MW from TAS1 into VIC1, sitting at 75% of its 459 MW export limit — the highest utilisation on the board right now, though it's not binding. This flow is consistent with the modest TAS1-VIC1 price gap (TAS1 at $99.77/MWh versus VIC1 at $109.48/MWh), with Tasmanian generation continuing to find a home in the mainland market. Heywood (V-SA) is also flowing solidly at 320.84 MW from VIC1 into SA1, around 60% of its 534.64 MW export limit, tracking the $6.95/MWh premium in SA1 ($116.43/MWh) over VIC1. Murraylink (V-S-MNSP1) is flat at zero, sitting completely idle between the two states.
QNI (NSW1-QLD1) is exporting 489.63 MW from QLD1 into NSW1 — flow is negative-signed per the from/to convention, meaning power is moving north-to-south — at roughly 45% of its 1078.19 MW import limit into NSW1. This aligns with QLD1 holding the lowest mainland price at $103.51/MWh against NSW1's $110.96/MWh, with cheaper Queensland generation flowing south. Directlink (N-Q-MNSP1) is barely used at -17 MW, well within its modest 91 MW capacity, contributing little to the QNI corridor's overall transfer. VIC1-NSW1 shows a light 49.46 MW flow from VIC1 to NSW1, under 10% of its 544.34 MW export limit, reflecting the narrow $1.48/MWh spread between the two regions.
None of the six interconnectors are currently binding, and utilisation outside Basslink and Heywood remains moderate, suggesting no acute transmission bottlenecks are constraining price convergence this morning. Active constraint sets from the past week remain relevant to watch: the N-KKLS_967 constraint (Lismore-Koolkhan outage) continues to affect Directlink's LHS equations, while the S-TBSE and related constraint sets from the Tailem Bend-South East line outage touch V-SA, QNI, Basslink and Murraylink simultaneously — these remain in force and could tighten limits further if network conditions shift. The TAS1 lightning-related contingency reclassifications from 21 August have since been cancelled, so Basslink's Farrell-Reece corridor is back to standard non-credible contingency treatment, supporting its current high utilisation without additional constraint pressure.