Commodity Demand — SA1: Saturday 1 August 2026
South Australia's spot price sits at -$4.50/MWh as of 20:30 AEST, with demand at 1467 MW — a level that's kept prices negative for the past two hours despite an evening uptick from the 06:35 AEST trough of 650 MW. The overnight and early-morning period shows the clearest demand-price relationship today: as demand collapsed from 1717 MW at 22:00 (01 Aug trading) through to a low of 517 MW around 04:30, prices fell in lockstep from ~$100/MWh into negative territory, bottoming near -$12.67/MWh. Wind generation of 1564 MW against total demand of 1467 MW explains the negative pricing — supply is comfortably exceeding load, with the region exporting the surplus.
The trajectory through today's daylight hours shows a sharp demand ramp from the early-morning trough, climbing from 650 MW at 06:35 to a peak of 1957 MW at 09:10-09:15 AEST. This ramp drove prices from single digits into the $100-172/MWh range between 07:00 and 12:30, peaking at $172.95/MWh at 10:15 as demand pushed toward 1952 MW. This is a textbook demand-price relationship: every 100 MW of demand growth through the morning ramp corresponded to roughly $10-20/MWh of price lift, reflecting tightening supply margins as thermal and gas units were brought on to cover the gap left by moderating wind output (renewable penetration fell to 37-44% through mid-morning, its lowest point of the day, versus 97%+ overnight).
Forecasts point to a continued demand decline into tonight and tomorrow morning, with AEMO's latest projections showing forecast RRP falling to -$32/MWh by 02:30-03:00 AEST and -$62/MWh by 04:30 on 2 August, consistent with the load-window analysis identifying five low-price windows overnight, the deepest averaging -$57.85/MWh between 04:00-05:00. Wind output and cool 7°C overnight temperatures with minimal heating load support this negative-price outlook. A moderate price recovery is forecast for tomorrow's morning peak (~$101/MWh around 12:00 AEST target), though well below today's ramp intensity.
Demand-side risk factors are visible in AEMO notices: a Forecast LOR1 condition was flagged for SA on 29 July with reserve requirements of 386-400 MW against available capacity of 357-379 MW, and AGL's Torrens Island units (TORRB2, TORRB3) remain under active direction to synchronise and follow dispatch from 11:00 AEST tomorrow through 14:30, specifically for voltage support. This indicates the network is managing tight reserve margins during ramp periods even though bulk energy supply (via wind) is plentiful — a distinction traders should note between energy sufficiency and system security constraints. The Tailem Bend to South East 275kV line outage, rescheduled to conclude by 12:00 on 1 August, has also been shaping interconnector flows and may have contributed to intraday price volatility.