NSW1 experienced sustained negative pricing at approximately −$10.50/MWh across two consecutive intervals on 5 September 2026 at 02:25–02:55 UTC. The region's generation mix was dominated by renewable output (wind 1,910 MW and solar 1,261 MW) alongside coal generation (2,090 MW), creating structural oversupply during a low-demand overnight period.
The negative pricing reflects excess renewable generation that could not be economically curtailed or exported during the low-demand window. Multiple binding constraints with marginal values between $3.45 and $4.45/MWh indicate transmission limitations were active, preventing efficient redistribution of the surplus generation to demand centres or energy-constrained regions. The combination of high wind output, residual solar generation, and inflexible coal baseload created downward pressure on the spot price, with constraints limiting the market's ability to resolve the imbalance through inter-regional flows.
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.