Carbon Forecast: Tuesday 12 May 2026

NEM-wide carbon intensity sits at markedly different levels across regions at 06:30 AEST this Wednesday morning. Tasmania is the cleanest grid on the interconnect at 0.00 tCO2/MWh with 100% renewable output — hydro (1,105 MW) and wind (122 MW) covering the entire load. South Australia follows at 0.20 tCO2/MWh with 67% renewables, driven by 742 MW of wind and gas (OCGT 266 MW, CCGT 119 MW) filling the remainder. Queensland sits at 0.41 tCO2/MWh with 52% renewables — wind (1,437 MW) and battery (426 MW) displacing a significant portion of the 1,740 MW of black coal still online. Victoria is at 0.62 tCO2/MWh with 49% renewables; wind (1,069 MW), hydro (220 MW), and battery (280 MW) run alongside 1,640 MW of brown coal. NSW is the highest-intensity region at 0.65 tCO2/MWh, with black coal (5,616 MW) dominating and renewables contributing only 26% — wind (890 MW), hydro (748 MW), battery (281 MW), and solar (111 MW) make up the balance.

The generation mix driving these outcomes reflects a May morning profile: solar contribution is minimal or zero across all mainland regions at this hour, so overnight and early-morning intensity is carried almost entirely by thermal and hydro/wind combinations. The sharp intensity drops seen in the data around 14:30–15:30 AEST yesterday confirm that solar ramp-up is the primary mechanism compressing midday intensity — SA reached as low as 0.12 tCO2/MWh at peak solar output. NSW intensity has remained stubbornly above 0.55 tCO2/MWh through the daylight hours due to the scale of coal baseload relative to available renewable capacity.

For carbon-sensitive loads today, the optimal windows are concentrated between approximately 10:00 and 17:30 AEST across SA and QLD, where renewables — particularly wind and solar combined — push intensity to their daily troughs. SA is the strongest candidate, with midday intensity likely to fall into the 0.12–0.18 tCO2/MWh range again as solar generation ramps. QLD's midday window (roughly 10:00–15:30 AEST) offers 0.41–0.47 tCO2/MWh with renewable penetration above 50%. VIC intensity is expected to ease into the 0.59–0.62 tCO2/MWh range through the morning as wind holds firm, though without strong solar contribution in May the midday dip will be shallower than summer profiles. NSW offers the least flexibility for carbon-sensitive scheduling today; operators with discretionary loads in that region should target the 14:30–16:00 AEST window where intensity has previously tracked near 0.56 tCO2/MWh. As solar drops off post-17:00 AEST, expect intensity to climb in all mainland regions through the evening peak.