Interconnector Watch — Wednesday 29 April 2026

Six interconnectors are active across the NEM at 06:35 AEST, with three running at binding limits and a material constraint notice on QNI shaping the northern price spread. QNI (NSW1-QLD1) is fully bound at its import limit of -523 MW — flow is moving south from Queensland into NSW at that cap, with the constraint set I-QN_550 invoked following further restriction of the interconnector due to the Armidale–Sapphire 8E 330 kV line outage. That outage runs until 02 May, meaning QNI remains artificially curtailed through the week. Despite southward flow, NSW sits at $76.99/MWh against Queensland's $70.96/MWh — a $6.03/MWh spread that reflects NSW demand of 7,651 MW and the constrained import path preventing full price equalisation.

VIC-NSW is the dominant flow corridor right now, carrying 1,027 MW northward from Victoria into NSW and sitting exactly on its export limit of 1,027 MW — fully bound. This flow is the primary mechanism supporting NSW supply, driven by a stark price differential: Victoria is clearing at $8.15/MWh against NSW's $76.99/MWh, a $68.84/MWh spread. That gap persists precisely because VIC-NSW is at capacity and cannot pass additional cheap Victorian generation northward. Victorian demand sits at 5,025 MW, and surplus generation in that region is clearly competing against the interconnector ceiling.

On the SA corridors, Heywood (V-SA) is carrying 202 MW westward from Victoria into SA and is not binding — export headroom remains to 276 MW. Murraylink (V-S-MNSP1) is bound at -131 MW, also flowing into SA, at its import limit. Together these two links are suppressing SA prices: SA clears at $8.45/MWh, near-identical to Victoria's $8.15/MWh, confirming adequate transmission capacity is keeping those two regions in close price alignment. Basslink (T-V-MNSP1) is flowing -269 MW from Tasmania into Victoria, utilising 80% of its import limit of -336 MW and not currently binding — Tasmania at $95.55/MWh is the most expensive NEM region, and Basslink is providing export revenue relief but lacks capacity to fully close that premium. Directlink (N-Q-MNSP1) carries a minor -25 MW southward, well within its -105 MW import limit and non-binding.

The dominant market dynamic today is the VIC-NSW binding constraint amplifying the Victoria–NSW price wedge to nearly $69/MWh, while the ongoing QNI restriction under I-QN_550 caps northward NSW relief and maintains a residual NSW–Queensland spread. Traders with exposure across the VIC/NSW boundary face maximum congestion rent conditions on that corridor. The QNI constraint is a scheduled network outage risk through 17:00 on 2 May — any demand spike in NSW before that clears will have no additional import relief available from either the north or the Victorian corridor.