Interconnector Watch: Friday 26 June 2026

The dominant story across the NEM at 06:30 AEST is QNI (NSW1-QLD1) binding hard at its import limit of -590 MW, with flow running north-to-south — Queensland exporting 590 MW into NSW at full capacity. This is the only binding interconnector on the network right now and it is directly anchoring the $17.12/MWh price spread between NSW ($120.00/MWh) and QLD ($102.88/MWh). With QNI saturated at its import limit, the constraint is preventing any further arbitrage from closing that gap, and the spread is effectively locked in place until either demand conditions shift or the constraint relaxes.

VIC-NSW (VIC1-NSW1) carries a modest 65.92 MW northbound from Victoria into NSW, running at just 6.7% of its 983.44 MW export limit — well clear of any binding threshold. The $5.73/MWh spread between NSW and VIC ($120.00 vs $114.27/MWh) is consistent with a lightly loaded interconnector where some arbitrage is occurring but is not fully closing the gap, likely reflecting intra-regional losses and local constraint geometry rather than interconnector saturation. Heywood (V-SA) is flowing 77.72 MW westbound from VIC into SA and sits exactly at its import limit of -77.72 MW, making it effectively binding in the SA import direction, though AEMO has not flagged it as a formal binding constraint in the dispatch solution. This is worth watching: the $4.40/MWh spread between VIC and SA ($114.27 vs $109.87/MWh) is narrow but the interconnector has no headroom to absorb additional SA demand without relaxation of the limit. Several active market notices remain relevant to Heywood and Murraylink — the Buronga B Bus 7118 220kV isolator rating change (constraint set N-BU_7118, active since 23 June) continues to affect V-S-MNSP1 transfer limits, and the Roseworthy–Templers 132kV line outage constraint set S-TPRS, alongside the X3 Balranald–Buronga rating change, remain active and are constraining both V-SA and V-S-MNSP1 transfer capacity.

Murraylink (V-S-MNSP1) is carrying just -9 MW westbound into SA, well within its operating envelope, with the active constraint notices suppressing its transfer capability below normal limits. Basslink (T-V-MNSP1) is at zero flow, effectively dormant this interval, leaving Tasmania isolated at $79.18/MWh — the lowest regional price on the NEM by a margin of $30/MWh or more against every mainland region. With Basslink carrying nothing, Tasmanian surplus has no path to the mainland and the price divergence is unconstrained. Directlink (N-Q-MNSP1) is flowing -57 MW southbound from QLD into NSW at 38% of its import limit, complementing QNI's southbound flow. The active market notice flagging Directlink control unavailability (constraint set I-CTRL_ISSUE_TE, invoked 20 June) remains in force, limiting AEMO's ability to vary its output — a risk factor for QLD-NSW transfer management if QNI conditions change during today's peak.

The net picture is a NEM