Overnight trading was shaped by transmission constraints rather than fuel scarcity, with NEM-wide prices broadly firm but not extreme. NSW1 averaged $102/MWh (max $207/MWh) and VIC1 led slightly at $107/MWh (max $194/MWh), while Queensland ran cheapest at $58/MWh average after brief negative pricing of around −$2/MWh across two intervals in the early hours — a minor oversupply event that quickly cleared. Into Thursday morning, Victoria's spot was climbing through $119.97/MWh at 06:25 AEST with demand at 6,183 MW on a winter demand ramp. Watch: QNI was the sole binding NEM constraint at 06:35 AEST, exporting exactly 534.61 MW from NSW into Queensland at its import limit — any tightening there could push QLD prices higher as morning demand builds.
Tasmania is today's standout. The region achieved 100% renewable generation on 21 May 2026, with hydro running across multiple units at approximately 3,627 MW and wind contributing around 59 MW. Despite that, TAS1 prices held in the $99–$105/MWh range — elevated relative to what a fuel-cost-driven price might suggest. The reason is clear: a major binding constraint on the T_BLINK_TV_NGZ (Blinkwater–Tarraleah–Nigretta Zone) transmission corridor registered a shadow price of $7.308 million during the early morning period, indicating severe internal network congestion. A parallel NEM-wide constraint, C_N_QUORNP_009_L_H in the Quorn area (SA), also registered a $7.308 million shadow price — well above the $4–$12/MWh range of other active constraints. These are constraint events worth monitoring closely if you hold interconnector-exposed contracts or firming products in either region.
WA1 recorded the highest average price across all six regions over the past 24 hours at $115/MWh, with an intraday maximum of $185/MWh. No specific constraint or event data is available for the WEM in this period, but the elevated average is worth noting for WA-based energy managers and PPA counterparties reviewing settlement exposure. The WEM continues to trade independently of NEM dynamics.