Interconnector Watch

The tightest choke point right now is QNI (NSW1-QLD1), which is binding at –270.95 MW against an import limit of –275.51 MW — effectively at its northward transfer ceiling. That constraint is holding Queensland's price at $108.62/MWh just below NSW at $110.86/MWh; if QNI had more headroom, additional NSW supply would likely compress QLD prices further. Equally notable, Directlink (N-Q-MNSP1) is also binding, flowing –40 MW northward into QLD at its limit of –42 MW. Both interconnectors are saturated in the NSW-to-QLD direction, meaning Queensland is drawing every available megawatt across both routes but still can't fully bridge the ~$2/MWh spread to NSW.

VIC-NSW is the most active interconnector in volume terms, carrying 583.28 MW northward from Victoria into NSW against an export limit of 1,058.89 MW — running at roughly 55% of capacity and well clear of binding. This flow is consistent with Victoria's lower price ($97.53/MWh) relative to NSW ($110.86/MWh); the ~$13 spread is sustaining strong northward transfer. Heywood (V-SA) is flowing –315.37 MW from SA into Victoria, utilising 57% of its import limit of –550.78 MW and not binding. SA's price of $87.69/MWh sits $9.84 below Victoria, which explains why SA is exporting surplus — likely renewables-driven — across Heywood. Murraylink (V-S-MNSP1) is flowing a modest –27 MW from SA to Victoria, also well within limits, consistent with the same SA-to-VIC price gradient.

Basslink (T-V-MNSP1) is at zero flow, sitting idle between Tasmania ($96.72/MWh) and Victoria ($97.53/MWh). The near-zero price differential gives no economic incentive for transfer in either direction, and the interconnector sits unconstrained but commercially dormant.

On network security, two lightning-related contingency reclassifications are active in the market notices. The Bannaby–Mt Piper 500 kV N-2 event in NSW — which had directly constrained QNI, Directlink, and VIC-NSW — was cancelled earlier today, reverting those lines to non-credible status. Similarly, the Yallourn–Rowville 220 kV reclassification in VIC was invoked and then cancelled through the morning. Both constraint sets (N-5A6+5A7_N-2 and V-ROYP78_R_N-2) are now revoked, so the binding conditions on QNI and Directlink today reflect genuine transfer limits rather than lightning-induced security constraints. Traders should note that further storm activity in these corridors could rapidly re-invoke those constraint sets and tighten VIC-NSW and QNI headroom.