Interconnector Watch

Six interconnectors are operating across the NEM this morning, with two binding at their export limits and a clear north-south price wedge defining today's market structure. VIC1-NSW1 (Heywood's northern counterpart, the VIC-NSW interconnector) is flowing 654.85 MW northward from Victoria into NSW and is binding at its export limit of 654.85 MW — it cannot push any more power north. Murraylink (V-S-MNSP1) is simultaneously binding at its export limit of 164.72 MW, flowing eastward from Victoria into South Australia. These two binding constraints cap Victoria's ability to export surplus generation and are the primary driver of the sharp price divergence visible right now: VIC1 sits at -$3.55/MWh and SA1 at -$3.45/MWh, while NSW1 clears at $71.40/MWh and QLD1 at $78.08/MWh. Despite both northward and eastward interconnectors running at their caps, the low Victorian price indicates local generation exceeds what the constrained export paths can absorb.

QNI (NSW1-QLD1) is carrying 485.56 MW northward from NSW into Queensland, utilising 74% of its 652.2 MW export limit — substantial flow but not yet binding. The price spread between NSW ($71.40/MWh) and QLD ($78.08/MWh) is consistent with this direction and magnitude; QLD demand at 5,662.78 MW is drawing on NSW supply, with headroom remaining on QNI before it binds. The Northern Interconnector (N-Q-MNSP1) carries 33 MW northward toward Queensland, running at 43% of its 76.43 MW export limit and is not binding. Basslink (T-V-MNSP1) is at zero flow with no binding constraint, and Heywood (V-SA) is carrying a modest 36.37 MW westward from Victoria into SA — well within its 516.27 MW import capability and not binding. The V-SA flow at this low level, combined with Murraylink binding at full export, suggests SA's import appetite is currently being met primarily through the HVDC Murraylink path, with Heywood carrying only marginal additional volume.

The constraint notice history warrants attention for Basslink watchers. Through yesterday, AEMO reclassified the Gordon–Chapel St No.1 and No.2 220kV lines in TAS1 as credible contingency events on multiple occasions due to lightning activity, each time invoking the F-T-CSGO constraint set that sits on the Basslink LHS. The most recent cancellation notice (issued 06:19 AEST this morning) reverts those lines to non-credible status, meaning the associated export constraints on Basslink are currently revoked. With Basslink at zero flow regardless, the immediate market impact is nil, but the repeated reclassification cycle across the past 48 hours signals active storm activity in the Tasmanian transmission corridor and traders should monitor for reinstatement. TAS1 clears at $60.18/MWh against VIC1's -$3.55/MWh, a spread that would ordinarily incentivise southward Basslink flow (from TAS to VIC), but the zero flow reading suggests other operational factors — scheduling, hydro dispatch, or AEMO instruction — are holding the link idle this interval.

The dominant market dynamic this