Rooftop solar reaches new highs across NEM

Rooftop solar output across the National Electricity Market hit a new all-time peak of 17,488 MW at midday on Sunday, 495 MW higher than the previous record set two weeks prior. Combined distributed and utility-scale solar met 72.29% of NEM consumption at that moment. Four new records were set across three states in five days: Victoria reached 4,191 MW, South Australia 2,070 MW, and New South Wales 6,346 MW. Between January and September 2026, renewables averaged 44% of NEM-wide generation. About 4 million homes and businesses have installed an estimated 22 GW of rooftop PV capacity.

Where this fits

Rooftop solar's rapid growth underscores the renewables-only path's core reliability problem: output that swings wildly with weather and time of day. A grid meeting 72% of daytime demand from solar is not a stable grid. That peak instantaneous output masks the volatility that requires either massive battery storage, gas peaking capacity, or both. None of those costs appear in the headline. The underlying issue is that firm, dispatchable power, which can run when the sun sets and clouds roll in, remains essential but increasingly expensive to hold in reserve while renewables capture the daytime market.

What it means

A grid with this solar penetration needs reliable firming capacity standing ready for every sunset and every cloudy day. Australia is meeting that demand with gas, which burns faster and emits more carbon per megawatt-hour than it would in a firm baseload role. Nuclear, banned by law, would deliver that same firming at lower lifecycle emissions and zero fuel-supply vulnerability to geopolitical coercion. The records tell only half the story: they count the sunny hours, not the cost of resilience on the windless nights.