Victoria experienced sustained negative pricing on 27 July 2026, with two consecutive intervals settling at approximately −$4.70/MWh, followed by a broader period of negative pricing across seven intervals. Wind generation dominated the supply mix at over 7,500 MW combined output, whilst brown coal contributed approximately 3,543 MW, creating significant structural oversupply in the region.
The negative pricing reflects excess renewable generation that could not be economically absorbed within the region. Wind generation at these levels, combined with inflexible brown coal baseload, created a supply-demand imbalance requiring either export or withdrawal of higher-cost generation. Binding constraints with positive marginal values (ranging from $5.17 to $6.80/MWh) indicate transmission or system strength limitations preventing efficient dispatch of excess supply across interconnectors, forcing the market to pay generators to reduce output rather than export at acceptable prices.
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.