Interconnector Watch: Friday 19 June 2026

Six interconnectors are active across the NEM at 06:30 AEST, with three running at their export limits and directly shaping regional price spreads. VIC1-NSW1 (Heywood's northern cousin, the Victoria–NSW interconnector) is binding at 729.56 MW northbound into NSW, sitting exactly at its export ceiling. Heywood (V-SA) is also binding, pushing 591.09 MW westbound into South Australia at its export limit. Murraylink (V-S-MNSP1) completes the Victorian export trifecta, binding at 54 MW into SA. With Victoria at $57.48/MWh — the cheapest mainland region — these three binding export constraints are the direct mechanical explanation for the price wedge: NSW clears at $79.00/MWh, SA at $71.54/MWh, and QLD at $80.72/MWh. Victoria cannot export any further volume into either NSW or SA, so those regional prices cannot converge downward toward Victoria's level.

On the north–south axis, QNI (NSW1-QLD1) carries 51 MW northbound into Queensland and is not binding — its export limit is 65.96 MW, leaving roughly 15 MW of headroom. That slack explains why the NSW–QLD spread is tight at $1.72/MWh rather than the wider gaps seen on the Victorian interconnectors. Directlink (N-Q-MNSP1) adds a marginal 9 MW northbound into QLD, also well within its 23.96 MW export ceiling and not binding. Basslink (T-V-MNSP1) is flowing 196.69 MW northbound from Tasmania into Victoria against an import limit of 196.69 MW — it is at its import ceiling — which explains Tasmania's $27.20/MWh price, the lowest in the NEM. Tasmania is exporting as hard as Basslink currently allows; without that constraint, Tasmanian generation would face even lower clearing prices.

Several active network constraint notices are bearing on these conditions. The Kerang–Koorangie 220 kV line outage (invoked 9 June, constraint set V-KGKO) explicitly constrains V-S-MNSP1, T-V-MNSP1, V-SA, and VIC1-NSW1 simultaneously — this single unplanned outage is a material contributor to the binding limits on all three Victorian export interconnectors today. The APD A2 500/220 kV transformer outage (10 June, constraint set F-I\_ML\_APD\_LOAD) adds a further restriction on Basslink's T-V-MNSP1, consistent with it running hard against its import ceiling rather than its higher 309.2 MW export limit. The automated security constraint on N-Q-MNSP1 (CA\_BRIS\_593C7214, active since 10 June) continues to cap Directlink, and updated North Queensland system strength constraints (Q-NIL set, implemented 18 June) remain active, though N-Q-MNSP1 shows no binding effect at current flows.

The net picture: Victoria is the low-price hub, constrained from fully arbitraging into NSW and SA by binding limits and ongoing network outages. Tasmania is price-isolated at the bottom by Basslink running at its import ceiling. The $53.52/MWh spread between Tasmania and QLD — the widest pair in the NEM right