Interconnector Watch: Tuesday 26 May 2026

At 6:30 AEST this morning, two of the NEM's six interconnectors are binding, directly shaping the price landscape across the eastern grid. QNI (NSW1-QLD1) is exporting 583.74 MW from Queensland into New South Wales and is binding at its import limit of -583.74 MW — the link is fully constrained in the northbound direction, with Queensland unable to receive any additional imports from NSW. This is consistent with QLD pricing at $144.50/MWh versus NSW at $161.92/MWh; the 17.42 $/MWh spread reflects the constraint preventing NSW from drawing further on Queensland supply to relieve its higher prices. Heywood (V-SA) is also binding, exporting 436.65 MW from Victoria into South Australia at its export limit. SA sits at $170.44/MWh — the highest price in the NEM today — while Victoria clears at $144.06/MWh, a $26.38/MWh spread that Heywood cannot arbitrage further given it is against its export ceiling. The Tailem Bend 275 kV East Bus outage (constraint set S-TB275_E_BUS, active since 24 May) remains on the LHS for V-SA and is a contributing factor to the constrained SA import capacity.

VIC-NSW is carrying 488.11 MW northward from Victoria into NSW and is not binding, with headroom to its 1,068 MW export limit. This flow is directionally consistent with Victoria pricing $17.86/MWh below NSW, and the unconstrained link is providing partial but incomplete price equalisation between the two regions. Murraylink (V-S-MNSP1) is passing 35.55 MW from Victoria into SA and is binding at its export limit, adding a marginal but fully utilised supplementary path alongside Heywood for the VIC-SA corridor. Basslink (T-V-MNSP1) is carrying zero flow between Tasmania and Victoria; TAS clears at $87.18/MWh, the lowest price in the NEM, and with no net transfer occurring the $56.88/MWh discount relative to Victoria is not being arbitraged. The N-Q-MNSP1 Directlink is flowing 41 MW southward from Queensland into NSW, operating within limits and not binding.

Two constraint notices warrant attention for today's trading. From 10:00 AEST this morning, AEMO will activate the Murraylink dynamic rating forecast model in pre-dispatch and PASA, enabling constraint equations VSML_RAT_LIM_DYN and SVML_RAT_LIM_DYN. This changes how Murraylink's thermal limit is represented in forward schedules and may adjust pre-dispatch flows and prices in the VIC-SA corridor during the morning. Separately, the Koorangie to Wemen 220 kV line outage (constraint set V-KOWE, active since 25 May) continues to place equations on the LHS of V-S-MNSP1, T-V-MNSP1, V-SA, and VIC1-NSW1, meaning the network topology is currently tighter than system normal for Victoria's export capacity in multiple directions. Traders with exposure to VIC, SA, or NSW prices should treat the 10:00 Murraylink constraint activation as a potential pre-dispatch repricing event for the SA corridor this morning.