Tasmania experienced 100% renewable energy penetration during the evening of 11 July 2026, with wind and hydro generation combining to meet all demand. Regional reference prices fell into negative territory, reaching -$4.92/MWh in the first settlement period before stabilising near zero to -$1.21/MWh across the subsequent five-minute intervals.
The negative pricing reflects an oversupply of renewable generation relative to local demand, with wind output exceeding 475 MW and hydro generation exceeding 270 MW whilst dispatchable gas capacity remained offline. Multiple binding constraints with non-trivial marginal values (F_I+RREG_0220 at $3.44/MWh and F_T+RREG_0050 at $3.07/MWh) indicate that dispatch limitations rather than demand-side factors were constraining the system, likely preventing full export of excess renewable output and forcing price suppression through local 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.