Rooftop PV system sizes are shrinking in line with battery rebates, but it’s still a bumper year for home solar

Australia installed over 311 MW of rooftop solar in September 2026, with the year-to-date tally the highest on record and running 43 per cent ahead of the same point last year. Average system sizes have fallen to just under 10 kW, down from peaks above 12 kW earlier in the year, tracking the reduction in battery rebate sizes from 50 kWh to the 20-25 kWh range. The 10-15 kW bracket remains the largest installed segment. The market remains buoyant despite the lower battery incentives.

Where this fits

This story is a materials and supply-chain dependence story. Rooftop solar is growing fast, which means demand for panels, inverters, and batteries is growing faster. Nearly all of these components come from China's manufacturing base, much of which runs on coal power. The shift toward smaller batteries paired with smaller solar arrays does not change the underlying dynamic: Australia is building a distributed, weather-dependent generation fleet that requires a long, vulnerable supply chain anchored in Beijing's strategic territory.

What it means

Growth in rooftop solar and battery uptake is real and rapid, but it deepens Australia's reliance on Chinese-controlled supply chains for the physical hardware of energy transition. If that supply chain faces disruption, sanctions, export controls, supply shock, Australia has no domestic manufacturing base to fall back on. A firm, domestically-sourceable alternative like nuclear is banned by law. The transition is being built on the assumption that Chinese supply will remain stable, stable pricing, and stable goodwill. That is a national security bet, not an energy bet.