Carbon Forecast: Sunday 28 June 2026

Carbon intensity across the NEM is sharply divergent this morning. Tasmania sits at 0.00 tCO2/MWh with 100% renewable generation — hydro at 1,066 MW and wind at 195 MW accounting for the entire dispatch. South Australia is effectively decarbonised at 0.019 tCO2/MWh with 96% renewable penetration, driven by 1,471 MW of wind against a minimal 60 MW CCGT gas contribution. At the other end, Victoria carries the highest intensity at 0.737 tCO2/MWh with renewables at 39% — brown coal at 3,966 MW dominates the stack, supplemented by 2,441 MW of wind and trace hydro and gas. NSW sits at 0.639 tCO2/MWh with 27% renewable penetration; black coal at 5,197 MW is the dominant source, with wind (1,072 MW), hydro (660 MW), and battery (231 MW) rounding out the mix. Queensland registers 0.577 tCO2/MWh at 32% renewable share — black coal at 4,537 MW leads, with wind at 1,845 MW and gas OCGT at 598 MW providing the remainder alongside battery and hydro.

Looking at the day's trajectory, SA and Tasmania present consistently low-intensity windows across all hours and are effectively always-on green windows for carbon-sensitive scheduling. SA did see a brief morning rise to around 0.107 tCO2/MWh between 07:00–10:00 AEST as demand lifted and gas provided firming support, before falling back below 0.020 tCO2/MWh — that pattern is likely to repeat this evening as wind output eases with the diurnal cycle. Victoria's intensity trended down through the mid-morning and afternoon as wind ramped into the 2,400 MW range, reaching a low near 0.637 tCO2/MWh around 19:00 AEST, but it is now creeping back toward 0.737 tCO2/MWh as wind backs off and brown coal holds its baseload position. No meaningful solar contribution is present across any region given the winter solstice period, so there is no midday dip to anticipate today.

For carbon-sensitive loads in NSW and Queensland, the most favourable windows observed over the past 24 hours occurred in the early-to-mid morning AEST period — roughly 10:00–16:00 AEST — when wind generation was at its strongest relative to thermal dispatch, pushing NSW intensity briefly into the 0.573–0.580 tCO2/MWh range and QLD toward 0.508–0.515 tCO2/MWh. With solar absent and wind the primary variable, intensity in those two regions will track inversely with wind output through the rest of today. Operators scheduling flexible loads or battery charge cycles for emissions reduction purposes should target SA interconnector-linked opportunities or Queensland's overnight wind-firming window — around 23:30–00:30 AEST — where intensity historically drops toward 0.507–0.510 tCO2/MWh based on today's observed data.