Carbon Forecast

Tasmania is running at 0.00 tCO2/MWh with 100% renewable penetration — 560 MW of hydro carrying the entire load, no gas or wind contribution required. That is the cleanest grid on the NEM by a wide margin and has held that position consistently across the entire observation window. South Australia is the next cleanest at 0.35 tCO2/MWh with 34% renewables, though that figure reflects a heavily gas-backed overnight position: 359 MW of gas CCGT and 191 MW of gas OCGT are doing the heavy lifting, with wind at 276 MW the only renewable contribution and solar offline. SA's intensity peaked above 0.47 tCO2/MWh during the 10:00–11:00 AEST window yesterday when renewables fell below 5%, so the current reading should not be taken as representative of daytime conditions.

Victoria is the dirtiest region at 0.95 tCO2/MWh with only 21% renewables. The driver is 2,194 MW of brown coal running as baseload, with wind contributing just 28 MW and hydro 43 MW — both negligible. VIC1 intensity was tracking above 1.10 tCO2/MWh through the 02:00–05:00 AEST period and only improved materially when solar began ramping yesterday morning; without significant wind the brown coal floor keeps intensity structurally elevated. Queensland sits at 0.84 tCO2/MWh with under 3% renewables — 2,708 MW of black coal dominant, solar at just 8.5 MW (pre-dawn), and renewables effectively absent overnight. NSW is at 0.80 tCO2/MWh with 9% renewables, 6,580 MW of black coal dominating, hydro at 796 MW providing the main low-carbon contribution, and wind at only 47 MW.

The green windows for today follow solar irradiance curves. In NSW and QLD, intensity improvement will begin around 07:30–08:00 AEST as utility solar ramps; yesterday's data shows NSW dropped from ~0.79 to ~0.71 tCO2/MWh between 07:00–09:30 AEST before wind dropped off and coal reasserted. SA showed its best renewable penetration at 17:00 AEST yesterday (74% renewables, 0.13 tCO2/MWh) driven by afternoon wind, and again late evening — but that was an anomalous wind event; this morning's reading suggests a gas-heavy day ahead until wind strengthens. Victoria's best window yesterday was 10:00 AEST at 0.82 tCO2/MWh with 33% renewables, driven by solar — expect a similar mid-morning dip today if conditions hold.

For carbon-sensitive load scheduling: TAS1 is clean around the clock — schedule flexible industrial loads there without restriction. For mainland regions, target the 09:00–12:00 AEST window in NSW and VIC when solar penetration peaks; avoid 13:00–20:00 AEST in QLD and NSW where coal dominance is greatest and renewables are minimal. SA afternoon wind (typically 15:00–19:00 AEST) offers the best mainland green window if yesterday's pattern repeats, but SA's intraday volatility is high — confirm in real time before