VIC1 experienced sustained negative pricing across 3 intervals on 9 June 2026, with prices reaching a minimum of -$11.74/MWh at 16:45. The region had substantial wind generation (approximately 6,562 MW combined) paired with significant brown coal generation (3,139 MW), creating oversupply conditions during a low-demand period.
The negative pricing was driven by an excess of inflexible generation relative to demand, with wind output particularly elevated during the late afternoon period. Multiple binding constraints with positive marginal values (ranging from $3.76 to $7.45/MWh) indicate that dispatch was constrained by transmission or operational limits rather than by marginal generation costs, preventing the system from reducing output or exporting excess energy effectively. This mismatch between available supply and constrained transmission capacity forced prices negative to incentivise demand response and reduce generation.
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.