Tasmania experienced very high renewable penetration of 97.9% on 16 September 2026 during the early morning period (07:05–07:30), driven by substantial hydro generation (1,164–1,164.6 MW) and moderate wind output (186.7–208.7 MW). Regional reference electricity prices rose steadily from $88.20/MWh to $104.42/MWh over the 25-minute window, despite the dominant renewable generation mix.
The price increase occurred alongside binding constraints with non-zero marginal values (constraint F_TASCAP_RREG_0220 ranging from $7.79 to $7.22/MWh, and F_T+RREG_0050 at $2.79/MWh), indicating that physical or operational limits on the power system—rather than fuel scarcity—were constraining supply and supporting prices. The high renewable penetration itself did not suppress prices to zero, suggesting that constraints on interconnection capacity, regional regulation requirements, or network topology actively prevented further price suppression despite abundant low-marginal-cost generation.
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.