regional sa — SA1

SA1 spot is sitting at $38.47/MWh at 17:00 AEST, up sharply from the overnight trough where prices ran negative for an extended stretch — dropping as low as -$59.04/MWh between roughly 23:25 and 00:05 AEST yesterday as solar and wind surplus overwhelmed daytime demand. The morning ramp has pushed prices steadily higher since around 15:00 AEST, consistent with the typical pre-evening-peak trajectory as rooftop solar output fades. Total demand is 1,478.75 MW, tracking upward from the midday low of around 225–270 MW seen during peak solar hours.

The current generation mix is almost entirely wind-led, with 542.77 MW of wind carrying the bulk of local dispatch alongside 83.36 MW of gas CCGT. Gas OCGT is offline at zero output, and utility-scale solar has dropped to zero as expected at this hour. Renewables account for 88.86% of generation, which is consistent with the sustained overnight and morning period where the renewable share held above 88–93% across multiple intervals. Carbon intensity is 0.0546 tCO2/MWh — well below the 0.24 tCO2/MWh recorded at the start of the observed history window on the evening of 10 March, confirming the wind-dominant dispatch profile has materially cleaned up the grid.

Predispatch forecasts point to a material softening from current levels. The most recent forecast run has the next tradeable interval at $8.95/MWh, with subsequent windows tracking in the $8–$18/MWh range through the overnight period. This aligns with yesterday's overnight pattern where prices collapsed once evening demand peaked and then wound back. Flexible load operators and battery operators should note the overnight window around 07:00–14:00 AEST today is forecast to be another extended negative-price period if wind output remains elevated — yesterday saw near-continuous negative pricing across that solar-peak window, with prices touching -$59/MWh at the nadir. No active market notices are in effect for SA1.

Sustainability managers should flag that the 88.86% renewable penetration and 0.0546 tCO2/MWh intensity reading represents one of the cleaner sustained grid states on record for this observation window. Grid stress is scored at 72.6/100, reflecting the interconnector dependency and voltage management complexity that accompanies high renewable penetration in SA — traders with Heywood exposure should monitor for potential constraint events as the evening peak develops through 18:00–20:00 AEST.