Carbon Forecast: Tuesday 23 June 2026

Tasmania sits at 0.00 tCO₂/MWh with 100% renewable penetration at 06:30 AEST, running entirely on hydro and wind — the cleanest signal on the NEM by a wide margin. South Australia is next at 0.53 tCO₂/MWh with only 8% renewables at present, its mix dominated by gas OCGT (667 MW) and CCGT (575 MW) with wind contributing just 61 MW. NSW sits at 0.70 tCO₂/MWh (18% renewable), with 7,149 MW of black coal as the base and hydro (1,246 MW) providing the largest non-thermal contribution. Queensland is at 0.70 tCO₂/MWh (18% renewable), similarly anchored by 5,308 MW of black coal and 812 MW of gas OCGT. Victoria carries the highest intensity at 0.89 tCO₂/MWh with 4,201 MW of brown coal underpinning the grid alongside 677 MW of gas OCGT; wind at 914 MW provides the primary renewable contribution there but sits at just 22% penetration.

The trajectory through this morning reflects a characteristic winter weekday pattern. In NSW and Queensland, intensity climbed steadily from overnight lows — NSW touched 0.54 tCO₂/MWh around 12:55 AEST with 38% renewables, and Queensland was well below 0.46 tCO₂/MWh between 09:30–12:30 AEST with renewable penetration above 47% — before demand ramp-up pushed both regions above 0.70 tCO₂/MWh through the afternoon and evening peak. Victoria followed a similar arc but from a higher base, reaching 0.97 tCO₂/MWh during the 18:30–19:30 AEST window. South Australia's lowest-intensity period came in the early hours — intensity dipped to 0.31 tCO₂/MWh at 14:30–15:00 AEST with renewables above 44% — driven by overnight wind generation before those resources eased heading into the business day.

For carbon-sensitive loads today, the best windows have already passed for most mainland regions. The overnight-to-early-morning period (roughly 08:00–10:00 AEST) offered the lowest mainland intensities, particularly in Queensland and NSW where renewable fractions were highest. The remainder of the day into the evening peak will maintain elevated intensities across NSW, QLD, and VIC as thermal generation holds firm to meet winter demand. SA's intensity is likely to ease modestly if wind output recovers through the afternoon, but with only 61 MW of wind currently dispatched against over 1,240 MW of gas, any improvement depends on wind conditions. Tasmania remains the single viable zero-intensity option for flexible loads with interconnector access, running at 100% renewable through hydro and wind for virtually the entire 24-hour period to date.