Tasmania achieved 100% renewable generation on 21 May 2026, with hydro power dominating the supply mix at approximately 3,627 MW across multiple units and wind contributing around 59 MW. Whilst renewable penetration was complete, regional prices remained elevated at $99–$105/MWh across the five settlement periods, suggesting that grid constraints rather than fuel costs were the primary price drivers.
The sustained price elevation despite 100% renewable generation indicates that binding network constraints—particularly F_T+RREG_0050 and F_MAIN+RREG_0220 with marginal values of $4.80–$5.81/MWh—were active scarcity mechanisms limiting efficient power transfer. These constraints likely reflect transmission limitations on interconnectors exporting Tasmanian renewable supply to mainland markets (VIC/NSW), causing local congestion and preventing wholesale price compression that would normally occur under abundant renewable supply conditions.
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.