Interconnector Watch

At 17:30 AEST, VIC-NSW (VIC1-NSW1) is binding at its export limit of 828.54 MW, fully saturating northbound capacity from Victoria into NSW. This constraint is directly driving the $30.79/MWh price spread between VIC1 at $30.22/MWh and NSW1 at $61.01/MWh — cheap Victorian generation cannot clear the congestion point, leaving NSW to source from higher-cost local and Queensland supply. QNI is running 176.06 MW northbound (NSW to QLD) against an export limit of 840.75 MW, well below capacity at roughly 21% utilisation and non-binding. The $3.34/MWh NSW-QLD spread is narrow and consistent with unconstrained flow in that direction.

Basslink (T-V-MNSP1) is binding at its import limit of -21.04 MW, flowing from Victoria into Tasmania at just 21 MW. This is a hard constraint on the TAS import side, and it is isolating Tasmania from cheaper mainland generation. The result is TAS1 pricing at $112.76/MWh — $82.54/MWh above VIC1 — a significant dislocation that would otherwise be arbitraged away if Basslink had headroom. No Murraylink losses data is available, but V-S-MNSP1 is flowing 39.73 MW into SA (negative convention, VIC to SA) and is non-binding at 27% of import capacity. Heywood (V-SA) is exporting 54.94 MW into SA at its export limit, technically binding on that side, contributing to SA1 sitting at $38.47/MWh — an $8.25/MWh premium to VIC1 but well below NSW1 and QLD1, reflecting partial supply from Victoria.

No constraint notices are active in the current dataset. The dominant market dynamic this interval is the binding VIC-NSW constraint suppressing Victorian prices while elevating NSW and, indirectly, Queensland. Traders with exposure to VIC1 off-peak baseload are absorbing the discount; NSW1 shorts are facing above-average spot. The Basslink binding constraint warrants monitoring for Tasmanian hydro dispatch strategy — at $112.76/MWh TAS1 is well above water value thresholds for most operators, creating incentive to export but constrained by the interconnector itself.