Interconnector Watch: Wednesday 29 July 2026

SA1 prices sit at $353/MWh this morning, the highest in the NEM, and both interconnectors serving the region are running near or at full capacity as VIC and NSW export toward the tighter SA market. Murraylink (V-S-MNSP1) is binding at 179.4 MW, sitting right at its 179.38 MW export limit from VIC into SA — fully utilised. Directlink (N-Q-MNSP1) is also binding, flowing 31.9 MW from QLD into NSW, pinned against its -31.9 MW import limit. Heywood (V-SA) is flowing 69.7 MW from VIC to SA, also at its export limit though not flagged binding in this snapshot, reinforcing the VIC-to-SA transfer pattern.

The VIC-to-SA transfers are consistent with the price spread: VIC sits at $132.86/MWh against SA's $353/MWh, a $220/MWh differential that's incentivising maximum flow on both Heywood and Murraylink simultaneously. AEMO has an active automated constraint set (CA_SYDS_597B5710, invoked 0130 hrs 29 July, still in force) managing power system security in VIC, with both V-S-MNSP1 and V-SA on the left-hand side — this is likely capping the transfer limits rather than a thermal or stability issue elsewhere, and explains why Murraylink's export limit exactly matches current flow.

Basslink (T-V-MNSP1) is flowing 384.3 MW from TAS to VIC, well within its 456 MW export limit and not binding, with TAS at $120.17/MWh and VIC at $132.86/MWh — a modest $12.69/MWh spread supporting continued northward flow. QNI (NSW1-QLD1) shows -870.3 MW, indicating a substantial flow from QLD into NSW, but sits well inside its -1078 MW import limit, non-binding, despite QLD's $121.12/MWh sitting below NSW's $138.96/MWh. VIC-NSW (VIC1-NSW1) is flowing 208 MW into NSW, also non-binding with ample headroom against its 1345.21 MW export limit. Overall, congestion today is concentrated on the SA import paths, with Murraylink and Directlink both constrained near capacity while the larger NSW-QLD-VIC-TAS transfers retain spare capacity and are not driving material price separation between those four regions.