Interconnector Watch: Thursday 25 June 2026

At 06:30 AEST, two of the NEM's six active interconnectors are binding at their import limits, directly shaping regional price spreads. QNI (NSW1-QLD1) is flowing 569.91 MW southward from QLD into NSW, sitting exactly at its import limit of -569.9 MW — fully constrained in this direction. Heywood (V-SA) is similarly pinned at its import limit of -244.33 MW, carrying 244.34 MW westward from VIC into SA. These two binding constraints are the dominant price-forming mechanism across the NEM right now. VIC and NSW are the relatively higher-priced regions at $179.90/MWh and $175.01/MWh respectively, while QLD at $144.55/MWh and SA at $139.99/MWh sit materially lower — a direct consequence of constrained export capacity out of those regions into the higher-priced south-east. TAS is the lowest mainland-connected region at $71.94/MWh, though Basslink (T-V-MNSP1) is currently carrying zero flow, leaving that spread uncaptured.

VIC-NSW is flowing 448.26 MW northward (VIC to NSW) against its export limit of 958.26 MW and import limit of -646.72 MW — currently non-binding with roughly 500 MW of headroom to its export cap. Murraylink (V-S-MNSP1) is moving 65.99 MW westward into SA at 72% of its import limit (-91.23 MW), non-binding but running with limited remaining capacity. The active Buronga B Bus 7118 220kV Isolator constraint (N-BU_7118, invoked 23 June) is curtailing Murraylink's transfer capability and is reflected in that tighter import limit. Directlink (N-Q-MNSP1) is flowing 65 MW southward from QLD into NSW at 57% of its import limit (-115 MW), also non-binding, though an active market notice flags that Directlink's output controls remain unavailable until further notice under constraint set I-CTRL_ISSUE_TE — limiting AEMO's ability to vary its dispatch in real time.

The $40.35/MWh spread between VIC ($179.90) and SA ($139.99) with Heywood binding at import capacity confirms SA's lower-priced supply cannot be exported further east in volume. Similarly, the $30.46/MWh spread between NSW ($175.01) and QLD ($144.55) with QNI binding reflects QLD's inability to export additional volume south despite the price incentive. The VIC-NSW spread of just $4.89/MWh is consistent with that interconnector operating well within its limits. Losses data are not reported in the current dispatch interval. The Roseworthy–Templers 132 kV outage (constraint set S-TPRS, active since 21 June) continues to interact with both V-SA and V-S-MNSP1 on the left-hand side of its constraint equations, contributing to the reduced transfer capability into SA from Victoria across both corridors.

Traders should note that the combination of binding QNI and Heywood, Directlink control unavailability, and the ongoing Buronga isolator rating reduction leaves limited relief valves for the NSW and VIC price premiums through the morning peak. Any uplift in