Commodity Demand — SA1: Saturday 15 August 2026
South Australia is trading at $67.88/MWh at 06:25 AEST with demand at 1289 MW, sitting in the tail of Saturday evening's decline. Wind is supplying 987 MW against total generation of roughly 1196 MW, keeping the region's carbon intensity at a low 0.0512 tCO2/MWh and renewable penetration at 89.55%. This continues the pattern seen through Saturday, where price and demand tracked closely: the overnight trough near 03:35-04:35 AEST saw demand fall to 649-863 MW with prices compressing to $35-64/MWh, while the evening peak between 21:20-22:00 AEST (14 August) pushed demand above 1400 MW and prices spiked to $162-264/MWh as wind output was insufficient to cover the ramp.
The demand-price relationship in SA remains highly elastic at the margins — small demand increases above ~1600 MW have repeatedly triggered price jumps of $50-100/MWh when wind generation is constrained, as seen in the 07:30-08:55 AEST window on 15 August where demand climbed from 1330 MW to 1784 MW and prices held in the $100-145/MWh band despite wind support. Conversely, when wind output is strong relative to demand (as now, with 987 MW wind against 1289 MW demand), prices sit well below $100/MWh even during shoulder periods.
AEMO's forecast for the next 24 hours points to a sharp overnight price collapse, with forecast RRP falling to single digits and briefly negative ($-3.09/MWh at 04:00-04:30 AEST on 16 August) as demand troughs and wind continues uncontested. Prices are forecast to recover through the morning ramp, reaching $89-101/MWh by 07:30-10:30 AEST as demand rebuilds, before easing again into the afternoon ($68-80/MWh) and holding in the high-$60s to high-$70s through evening. This matches the load-shifting windows identified for tomorrow's low-demand periods (01:00-05:00 AEST), where prices are forecast between -$2 and $10/MWh, offering clear arbitrage value for flexible load and battery charging.
On the demand-side risk register, AEMO's MTPASA notice flags a Low Reserve Condition forecast for July 2028 in SA, unrelated to today's operations but relevant for longer-term contracting. Closer to real time, the Murraylink control issue (now resolved) and ongoing Directlink control unavailability in NSW are worth monitoring given SA's reliance on interconnector flows during demand peaks — any transfer capability constraint during tonight's evening ramp (18:00-21:00 AEST) could amplify price volatility if wind output eases as forecast cloud cover (80% average tomorrow) suggests limited solar contribution to offset any gap.