QLD1 experienced sustained negative pricing in two consecutive intervals on 24 July 2026, with the minimum price reaching -$2.15/MWh during the late evening peak. The region was operating with high solar and coal generation (approximately 5,654 MW and 3,424 MW respectively) combined with modest demand during twilight hours.
The negative pricing reflects excess generation relative to demand, with solar output remaining substantial despite the late evening timing (suggesting the event occurred during the solar ramp-down phase). Multiple binding constraints with marginal values ranging from $2.55 to $5.56 appear to have constrained the ability to dispatch or export this surplus generation, forcing negative pricing to incentivise load increase or generation reduction. The binding constraint F_TASCAP_RREG_0220 showed the highest marginal values, indicating transmission or network limitations were actively suppressing the market-clearing price.
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.