Interconnector Watch: Wednesday 17 June 2026

Six interconnectors are active across the NEM at 06:30 AEST, with two binding hard against their limits and three active constraint notices continuing to shape transfer capability. The most significant binding constraint is Heywood (V-SA), which is flowing 270 MW from SA into Victoria — at its full import limit of -270 MW. With SA spot at -$2.00/MWh and Victoria at -$0.10/MWh, the price differential is negligible in absolute terms, but Heywood is fully saturated in the SA-export direction, meaning no additional relief is available to either region via this link. Murraylink (V-S-MNSP1) is simultaneously showing zero flow with both import and export limits at 0 MW, indicating the link is effectively offline or constrained out — likely a consequence of the active V-KGKO constraint set invoked following the unplanned Kerang–Koorangie 220 kV line outage on 9 June, which lists Murraylink on its left-hand side.

QNI (NSW1-QLD1) is the second binding interconnector, flowing 214.4 MW north from NSW into Queensland at its binding import limit of -214.4 MW. Queensland demand sits at 6,763 MW with a spot price of $78.73/MWh, closely matched by NSW at $79.49/MWh on 8,272 MW of demand — the near-identical prices confirm QNI is transferring at capacity with the spread fully arbitraged out. The active constraint set CA_BRIS_593C7214, invoked on 10 June to maintain power system security in Queensland, continues to cap Directlink (N-Q-MNSP1) at zero flow despite that link having nominal export headroom of 55 MW toward Queensland. Both northern interconnectors are therefore simultaneously constrained, leaving Queensland reliant on its own generation to meet any incremental demand today.

VIC-NSW is running 779.72 MW northward from Victoria into NSW and is sitting exactly at its export limit, making it effectively binding in practice even though it is not flagged as such. Victoria's near-zero price (-$0.10/MWh) versus NSW's $79.49/MWh represents the largest price spread on the mainland right now — a $79.59/MWh gap — and VIC-NSW is clearly arbitraging at full northward capacity. The active APD A2 500/220 kV transformer outage notice (invoked 10 June, constraint set F-I\_ML\_APD\_LOAD) continues to affect Basslink (T-V-MNSP1), which is carrying zero flow against a nominal export capacity of 125 MW toward Victoria. Tasmania is clearing at $25.89/MWh against Victoria's -$0.10/MWh, a spread that would ordinarily pull Tasmanian exports south, but the APD transformer constraint is preventing any flow. The combination of Basslink at zero and VIC-NSW at its export ceiling means Victoria's surplus generation has only one active export path to the mainland right now, and that path is already saturated.