Carbon Forecast

Tasmania is running at 0 tCO2/MWh with 100% renewable generation — hydro (366 MW) and wind (58 MW) carrying the entire load, as it has done consistently across every interval in today's dataset. That is the NEM's carbon floor, and it is not moving. South Australia is the next cleanest mainland region at 0.39 tCO2/MWh with 30% renewables, wind contributing 188 MW alongside gas CCGT (257 MW) and OCGT (174 MW) filling the balance. SA's intensity has been trending down through the evening from a daytime high above 0.53 tCO2/MWh when wind penetration collapsed to near zero mid-morning — a stark reminder of how exposed that grid is when the wind drops.

NSW is the dirtiest region on the NEM right now at 0.86 tCO2/MWh, with black coal (6,103 MW) dominating and renewables sitting at just 2.4% — wind contributing only 149 MW and solar effectively zero. Intensity has been climbing since solar dropped off around 15:00 AEST and is now at its worst level of the day. Queensland mirrors that picture at 0.85 tCO2/MWh, black coal (2,922 MW) accounting for the overwhelming majority of output with renewables at under 3%. Victoria sits at 0.75 tCO2/MWh — brown coal (1,559 MW) is the backbone, but 973 MW of wind is delivering 37% renewable penetration and keeping intensity materially below its overnight peak above 1.09 tCO2/MWh.

The trajectory for the rest of today is unfavourable for NSW and QLD. With solar generation now absent and no indication of significant wind uplift, both regions will remain above 0.85 tCO2/MWh through tonight. Victoria's wind is holding intensity in the 0.74–0.79 tCO2/MWh range and is unlikely to deteriorate sharply unless wind output falls. SA's intensity should continue drifting lower as wind picks up through the evening, consistent with the trend from 0.53 tCO2/MWh at midday toward the current 0.39 tCO2/MWh. The next meaningful green window across mainland grids will arrive tomorrow morning when solar ramps — SA and VIC typically see the sharpest intensity drops from around 08:00–10:00 AEST.

For carbon-sensitive load scheduling: avoid NSW and QLD for any flexible loads tonight — both are in their dirtiest window of the day and will remain so. SA is the best mainland option right now and improving; VIC is acceptable. Any operator with cross-border flexibility or behind-the-meter storage should target SA or VIC dispatch through the overnight period. If you are in NSW or QLD and can defer to tomorrow's solar window (08:00–13:00 AEST), the carbon saving will be material — NSW intensity dropped as low as 0.72 tCO2/MWh during peak solar hours in today's data, a 0.14 tCO2/MWh improvement over tonight's levels.