TAS1 experienced sustained negative pricing at approximately −$8/MWh across three consecutive intervals (05:45–05:50), with a spike to −$15.01/MWh at 05:45, driven by oversupply conditions during early morning low-demand periods. Wind generation remained elevated at 369–460 MW whilst hydro and gas-fired generation continued to operate, creating excess supply that the market cleared at negative prices.
The negative pricing reflects a supply-demand imbalance typical of early morning periods characterised by high renewable generation and minimal demand. Multiple binding constraints with marginal values between $6.44–$7.23/MWh restricted the ability to export excess generation or balance supply internally, forcing the market price into negative territory as generators with high marginal costs or inflexible dispatch obligations had to pay for removal of their output. The particular depth at 05:45 (−$15.01/MWh) suggests a sharper supply spike or temporary constraint tightening that compelled greater price adjustment to clear the market.
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.