Interconnector Watch: Saturday 16 May 2026

The dominant story across NEM interconnectors this morning is the binding constraint on QNI (NSW1-QLD1), where flow sits at -289 MW — exactly at the import limit of -289 MW, meaning the link is fully saturated in the northward direction, carrying power from NSW into Queensland. With QLD1 pricing at $91.60/MWh against NSW1 at $98.14/MWh, the spread is modest at $6.54/MWh, but the binding constraint confirms QNI is the active bottleneck suppressing further price convergence between the two regions. The Directlink outage (No.3 leg, active since 5 May, constraint set N-MBTE_1) continues to reduce N-Q-MNSP1 capacity, with that interconnector currently flowing -25 MW southward into NSW at well below its -89.9 MW import limit — constrained headroom here is compounding the QNI situation. The Armidale No.3 330/132 kV transformer outage (N-AR_TX, active since 8 May) is also limiting N-Q-MNSP1 capability and remains unresolved.

Murraylink (V-S-MNSP1) is at zero flow following an unplanned outage of the Redcliffs converter station that triggered constraint set I-ML_ZERO at 0145 AEST this morning. Two active market notices cover this event, and both import and export limits are showing zero, confirming the link is completely offline. The absence of Murraylink is directly relevant to the SA1–VIC1 price spread: SA1 is trading at $168.88/MWh against VIC1 at $157.23/MWh, an $11.65/MWh gap. Heywood (V-SA) is compensating, flowing 356 MW from VIC into SA against an export limit of 619.4 MW — utilisation is around 57%, with meaningful headroom remaining, but Heywood alone cannot replicate Murraylink's contribution to arbitrage, leaving SA with a persistent premium today.

VIC1-NSW1 (the main VIC–NSW interconnector) carries -502.5 MW flowing south from NSW into Victoria, and is at its import limit of -502.5 MW. While the binding flag is set to false in the dispatch data, the flow equalling the import limit warrants close monitoring — any increase in Victorian demand or southward price pressure could activate binding status. The $59.09/MWh spread between VIC1 ($157.23/MWh) and NSW1 ($98.14/MWh) is the largest bilateral spread on the NEM today and reflects Victoria's relative tightness; the Murraylink outage is a contributing factor given the active I-MURRAYLINK constraint set, which includes VIC1-NSW1 on its left-hand side. Basslink (T-V-MNSP1) flows 86.86 MW northward from Tasmania into Victoria at 69% of its 125 MW export limit, consistent with the VIC1 price premium; it is not binding and retains approximately 38 MW of additional export headroom. The $44.99/MWh spread between TAS1 ($112.24/MWh) and VIC1 ($157.23/MWh) supports continued Tasmanian export into Victoria for the remainder of today's trading.