VIC1 experienced sustained negative pricing at −$1.10–1.15/MWh across two consecutive intervals (02:50–02:55 on 22 July 2026), following a sharp price collapse from $10.65 to $1.42 in the preceding half-hour. The event occurred during off-peak night hours with very high wind generation (2,305–2,309 MW) and significant solar output (829.89 MW), creating substantial oversupply relative to demand.
The negative pricing resulted from excess renewable generation outpacing demand during a low-demand period, with inflexible brown coal generation (4,178 MW) unable to adjust downward sufficiently. Multiple binding constraints with marginal values ranging from $6.80–19.48 indicate congestion relief requirements and regional balancing needs that prevented economic dispatch from freely accommodating the high renewable output, forcing marginal generators into negative pricing territory to manage the supply surplus.
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.