Tasmania experienced sustained negative pricing across three consecutive intervals on 13 September 2026, with prices hovering around -$9.78/MWh between 01:50 and 02:00. The region generated approximately 1,208 MW from renewable sources (hydro and wind) alongside 248 MW of gas-fired generation and 125 MW of rooftop PV, creating an oversupply condition during a low-demand period.
Negative pricing in TAS1 reflects excess generation relative to local demand, likely driven by substantial hydro output (averaging ~339 MW across the interval) combined with wind generation (~217 MW) during the early morning low-demand trough. The presence of binding constraints with modest marginal values (approximately $4–$4.70/MWh) indicates that interconnector or network limitations prevented efficient export of surplus energy to neighbouring regions, forcing local prices into negative territory to manage oversupply.
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.