Interconnector Watch

VIC1-NSW1 (Heywood's northern cousin, the main Victoria–NSW link) is the most consequential interconnector right now, flowing 832.71 MW northbound from Victoria into NSW and sitting precisely at its export limit of 832.71 MW — it is binding. This cap is directly reflected in the price spread: Victoria clears at -$3.09/MWh while NSW sits at $76.99/MWh, an $80.08/MWh differential that would narrow further if additional capacity were available. The constraint is fully exhausting the northbound transfer capability and preventing Victorian surplus from fully arbitraging into the higher-priced NSW market.

Murraylink (V-S-MNSP1) is the second binding interconnector, flowing -150 MW — meaning 150 MW is moving from SA into Victoria — and sits exactly at its import limit of -150 MW. SA prices at -$3.00/MWh and Victoria at -$3.09/MWh are nearly co-priced in negative territory, so while the constraint is formally binding, the price signal driving the flow is marginal. Heywood (V-SA) is running in the same direction as Murraylink — 53.16 MW moving from SA to Victoria — but at only 9.5% of its import capacity of 561.18 MW, it is well clear of its limit. The combined SA-to-Victoria flow across both interconnectors totals roughly 203 MW with both regions in negative price territory, indicating surplus generation on the SA side is being absorbed eastward.

QNI (NSW1-QLD1) is carrying 74.86 MW northbound from NSW into Queensland, utilising around 12.7% of its 587.83 MW export limit and is not binding. The modest flow is consistent with the tight price spread — NSW at $76.99/MWh against QLD at $79.58/MWh, a gap of only $2.59/MWh. Active constraints on QNI remain in place following the 5 April unplanned outage of the Larcom Creek–Calliope River 8859 275 kV line in Queensland (constraint set Q-LCCP_8859), which also constrains N-Q-MNSP1. Murraylink's northern counterpart, N-Q-MNSP1, is carrying just 17 MW northbound at 25.7% of its 66.18 MW export limit and is not binding. Basslink (T-V-MNSP1) is at zero flow with an export limit of 0 MW, effectively idle in the southbound direction; earlier today a lightning-related reclassification of the Sheffield–George Town 220 kV lines in Tasmania invoked constraint set T-GTSH_N-2 against Basslink, though that reclassification has since been cancelled. Tasmania's $50.20/MWh price versus Victoria's -$3.09/MWh represents a $53.29/MWh spread that Basslink's current zero export limit is not available to arbitrage.

The dominant market dynamic right now is the binding VIC1-NSW1 constraint locking in an $80/MWh price wedge between the two largest regions. Traders holding exposure across that seam face maximum divergence; the constraint prevents further price convergence until either load conditions shift or the export limit is revised upward. The Murraylink binding condition adds a secondary layer on the SA–VIC seam, though its price