SA1 experienced high renewable penetration of 93.3% during the 21:35–22:00 settlement interval on 14 September 2026, driven primarily by strong wind generation (1031.38 MW) and substantial solar output (185.16 MW combined). Regional spot prices fell sharply from $22.32/MWh to lows of $7.96/MWh as renewable supply overwhelmed demand, with prices remaining suppressed in the $8–11/MWh range thereafter.
The steep price decline reflects the displacement of higher-cost thermal generation as wind and solar output saturated the market, creating downward pressure on the regional reference price. Multiple binding constraints with modest marginal values ($2.91–$2.99) indicate that network or plant-level limitations were active but not severe, whilst one constraint registered a higher marginal value ($51.90), suggesting localised congestion or regulation requirements exerted some upward pressure on costs; however, the renewable-driven supply surplus dominated price dynamics, resulting in the observed suppression of prices to low levels.
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.