Interconnector Watch: Saturday 29 August 2026

At 06:30 AEST, three of six interconnectors are binding against their limits, and flow patterns are actively arbitraging the regional price spreads across the NEM. QNI (NSW1-QLD1) sits at -1,318.72 MW, pinned to its import limit of -1,318.72 MW — flow is running from QLD1 into NSW1, consistent with QLD1's $63.73/MWh sitting well below NSW1's $83.99/MWh. Heywood (V-SA) is exporting 510.79 MW from VIC1 to SA1, bound at its export limit, as SA1's $86.44/MWh premium over VIC1's $73.73/MWh pulls flow south. Basslink (T-V-MNSP1) is also binding, carrying 437.39 MW from TAS1 to VIC1, well above its 239.5 MW import limit reference point and close to its 459 MW export ceiling — TAS1 at $66.00/MWh is exporting into the higher-priced VIC1 market.

Murraylink (V-S-MNSP1) is flat at zero, non-binding, offering no relief to SA1 despite the price differential Heywood is already exploiting — likely reflecting an outage or de-rating rather than a lack of arbitrage incentive. VIC1-NSW1 is flowing 655.51 MW from VIC1 to NSW1 but sits well inside its -65.24 MW to 1,063.46 MW range, not binding, giving NSW1 headroom to draw more from Victoria if needed. Directlink (N-Q-MNSP1) is flowing a modest 65 MW from QLD1 to NSW1, also non-binding within its -149.5 MW to 10.5 MW band.

The binding constraints on QNI, Heywood and Basslink are actively capping arbitrage and sustaining the observed price spreads: NSW1 ($83.99), SA1 ($86.44) and WA1 ($97.75, non-interconnected) hold the highest prices, while QLD1 ($63.73) and TAS1 ($66.00) remain comparatively cheap but constrained in their ability to export further. With QNI, Heywood and Basslink all at or near limits simultaneously, the NEM's three key transfer paths are collectively saturated this morning, meaning further convergence between regions depends on demand-side movements or generation dispatch changes rather than additional interconnector capacity.

On notices, a live inter-regional transfer limit variation from the 20 August Tailem Bend–South East No.2 275 kV outage continues to affect constraint sets spanning V-SA, NSW1-QLD1, T-V-MNSP1, V-S-MNSP1 and VIC1-NSW1, which may be contributing to Murraylink's zero flow. The Hazelwood bus tie outage constraint (V-NIL_HW_TIE) affecting Basslink, Heywood and VIC-NSW also remains active. Separately, updated North Queensland system strength constraint equations took effect from 27 August but are not currently binding on Directlink or QNI flows.