Interconnector Watch

At 16:30 AEST, two interconnectors are binding and actively shaping NEM price outcomes. QNI (NSW1-QLD1) is flowing 434 MW southbound from Queensland into NSW — at its import limit of 434 MW — meaning the link is fully constrained and preventing further arbitrage from closing the $81.69/MWh spread between Queensland ($72.75/MWh) and NSW ($154.44/MWh). Simultaneously, the Directlink (N-Q-MNSP1) is binding at its import limit of 151.6 MW, also flowing northbound into Queensland, reinforcing that Queensland is the low-price exporter into a constrained NSW market. Both constraints are hard floors on how much cheap Queensland generation can reach southern load centres today.

Heywood (V-SA) is carrying 425 MW westbound from Victoria into South Australia — 69% of its 615 MW export limit — keeping SA's price ($161.88/MWh) elevated relative to Victoria ($147.50/MWh) despite the flow. The $14.38/MWh spread suggests Heywood is doing useful arbitrage work but is not fully closing the gap, consistent with it running at a meaningful but non-binding utilisation level. Murraylink adds a modest 37 MW on the same west-to-SA direction, contributing a fraction of additional SA supply.

Basslink is carrying 197 MW northbound from Tasmania into Victoria, sitting at 75% of its 261.6 MW export limit and not binding. The $27.91/MWh differential between Tasmania ($119.59/MWh) and Victoria ($147.50/MWh) indicates continued incentive to push Tasmanian hydro north, and there is headroom to increase flow before the constraint bites. VIC-NSW is carrying just 14 MW northbound — negligible relative to its 1,000 MW export capacity — consistent with Victoria's price sitting below NSW and the lack of any binding constraint on that link. No constraint market notices are active across the NEM at this interval.

The dominant story today is the QNI binding constraint locking in an $81/MWh NSW-Queensland price wedge. Traders with exposure to NSW load or Queensland generation should note that this spread cannot tighten further while QNI remains at its import limit. Watch for any constraint relaxation or demand shift heading into the afternoon peak that could move that binding status.