Tasmania experienced 100% renewable generation on 10 July 2026 between 20:05 and 20:45 UTC, with hydro and wind supplying all system demand. Regional reference prices collapsed to near-zero levels (minimum $0.08/MWh) during this period, reflecting the absence of marginal fossil-fuel generation.
The price collapse was driven by the combination of abundant renewable supply (approximately 1,700 MW of combined hydro and wind output) meeting lower evening demand, which eliminated the need for high-cost marginal generation. Binding constraint F_TASCAP_RREG_0220 and F_T+RREG_0050 became active with marginal values of $3.66–$5.48/MWh, indicating physical or regulatory dispatch limits were constraining the system; however, these constraint marginal values were insufficient to support prices above near-zero levels given the excess renewable supply available.
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.