Carbon Forecast: Thursday 3 September 2026

South Australia is running at 0.137 tCO2/MWh with 75.4% renewable penetration this morning, the lowest carbon intensity on the mainland, on the back of 1,220 MW of wind generation against just 166 MW of gas OCGT and 232 MW of gas CCGT. Tasmania sits at 0 tCO2/MWh with 100% renewables, as usual, running almost entirely on 1,042 MW of hydro plus 406 MW of wind. NSW1 is at 0.689 tCO2/MWh (21.5% renewable), Queensland at 0.707 tCO2/MWh (19.3% renewable), and Victoria carries the highest intensity of the mainland regions at 0.804 tCO2/MWh with renewable penetration at 31.1%, reflecting 3,550 MW of brown coal output against 1,274 MW of wind.

The mix driving these numbers is clear: NSW is leaning on 5,278 MW of black coal with wind contributing 285 MW and battery output at 242 MW; Queensland's 5,764 MW of black coal dwarfs its 537 MW of wind and 24 MW of solar; Victoria's brown coal fleet remains the dominant source overnight with wind the main renewable offset. SA's near-total reliance on wind (with negligible solar output at this hour) is what's keeping its intensity near record lows, while Tasmania's hydro-wind combination keeps it emissions-free regardless of time of day.

Looking at the trajectory through today, overnight and early-morning data show a consistent pattern: intensity troughs across NSW, VIC and QLD typically occur between 00:00 and 05:00 AEST when wind generation peaks and demand is lower, with NSW dropping as low as 0.251 tCO2/MWh (71.4% renewable) around 11:30am UTC yesterday's equivalent window. As solar ramps through the morning and afternoon demand builds, intensity in NSW, VIC and QLD climbs steadily, peaking in the early evening (18:00-19:30 AEST) as solar drops off and coal/gas ramp to cover the evening peak — NSW reached 0.764 tCO2/MWh and VIC hit 0.909 tCO2/MWh in that window yesterday.

For carbon-sensitive loads today, the best windows to shift flexible demand are overnight into early morning (00:00-05:00 AEST) across NSW, VIC and QLD when wind contribution is highest and coal ramping is lowest. SA offers a near-continuous green window given its wind-dominated mix, though intensity there rises during the day as demand peaks force gas online (SA touched 0.485 tCO2/MWh around midday yesterday when wind eased). Tasmania remains the standout for any load requiring guaranteed zero-carbon supply, with no meaningful variation expected through the day. Avoid scheduling flexible load in NSW, VIC or QLD between 16:00 and 20:00 AEST, when intensity peaks as solar output fades ahead of the evening demand ramp.