Tasmania (TAS1) experienced sustained negative pricing at -$1.14/MWh across two consecutive intervals (23:20 and 23:25 on 2 August 2026), following a period of volatile pricing. The region was generating over 2200 MW of combined hydro and wind output during this period, with moderate OCGT contribution.
The negative pricing was likely driven by excess renewable generation (approximately 1500+ MW of hydro and 200–300 MW of wind) coinciding with constrained export capacity, as evidenced by binding constraints with significant marginal values, particularly the constraint T_BLINK_TV_NGZ ($8.352/MWh) which suggests a major interconnector limitation. With limited ability to export surplus generation and moderate local demand, the system required generators to bid below zero to facilitate dispatch and maintain balance.
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.