Carbon Forecast: Monday 17 August 2026
SA1 carbon intensity sits at 0.0154 tCO2/MWh this morning, the lowest in the NEM, with renewable penetration at 96.9% as wind (1,164 MW) covers almost all regional demand alongside 154 MW of battery discharge. TAS1 follows at 0.0631 tCO2/MWh and 90.3% renewables, hydro-dominant at 936 MW with wind contributing 222 MW. At the other end, VIC1 carries the highest intensity at 0.7162 tCO2/MWh despite 41.3% renewable share, a function of brown coal (4,265 MW) still meeting the bulk of underlying demand alongside wind at 2,992 MW. NSW1 sits at 0.6532 tCO2/MWh with black coal at 5,626 MW dominant over wind (1,131 MW) and hydro (417 MW), while QLD1 reads 0.6407 tCO2/MWh, black coal at 5,207 MW against 1,318 MW of wind.
The generation mix explains the spread directly: SA1 and TAS1 run on wind/hydro base with negligible thermal generation, holding intensity below 0.07 tCO2/MWh through virtually all of yesterday's trading period. NSW1 and QLD1 show wide intraday swings — NSW1 ranged from 0.4493 to 0.689 tCO2/MWh, QLD1 from 0.40 to 0.716 tCO2/MWh — tracking solar output through the middle of the day pulling intensity down before evening peak demand reverts generation to coal and gas. VIC1's range was narrower (0.73–0.90) given its comparatively low rooftop and utility solar contribution versus wind.
For today's outlook, expect NSW1 and QLD1 intensity to fall through mid-morning as solar ramps, likely bottoming in the 0.40-0.45 tCO2/MWh range around midday to early afternoon before climbing again through the evening peak from 17:00-20:00 AEST as solar drops off and coal/gas cover the ramp. VIC1 should track a shallower midday dip, likely 0.75-0.80 tCO2/MWh, given its wind-heavy but solar-light mix. SA1 and TAS1 remain the standout green windows all day — intensity in both stays below 0.08 tCO2/MWh continuously provided wind holds near current output, with no meaningful trajectory change expected. Carbon-sensitive loads seeking the lowest-intensity window nationally should target SA1 or TAS1 at any hour, or NSW1/QLD1 specifically between roughly 11:00 and 15:00 AEST when solar peaks.