VIC1 experienced sustained negative pricing over a 3-interval period on 19 September 2026, with prices reaching −$45/MWh at 03:45 and remaining in the −$30 to −$44/MWh range through 04:20. The event occurred during the early morning period with significant renewable generation from wind (approximately 2,502 MW combined) and solar (942 MW) alongside brown coal baseload (1,681 MW).
The negative pricing was driven by a binding constraint (F_T+LREG_0050) with consistently high marginal values of approximately $103.82–$103.84, which suppressed dispatch pricing in VIC1. The combination of elevated renewable output and coal-fired generation unable to rapidly reduce output during low-demand early morning hours created excess supply conditions, with the binding constraint preventing normal economic dispatch and forcing negative pricing to incentivise load participation or generation withdrawal.
Causal analysis generated by gridIQ's synthesis model from live AEMO market data: dispatch prices, generation mix, interconnector flows and market notices in the interval surrounding the event.