Australian households and small businesses have more than 3 million solar power systems on their rooftops after a record number were installed last year, even through the disruption of lockdowns.

With the Morrison government having joined most other wealthy nations in signing up to net-zero emissions by 2050, the Clean Energy Council said rooftop solar would be critical to achieving this target.

There were 279,000 solar systems installed in 2019 and about 369,000 in 2020, with growth continuing despite the pandemic, as large numbers of Australians worked from home and spent money on home improvements.

Australia leads the world in per-capita uptake of solar power, 22 per cent higher than Germany or Japan in 2020, according to the International Energy Agency.

“It’s obvious Australians want rooftop solar, they’re comfortable with the technology and it’s affordable,” said Kane Thornton, chief executive of the Clean Energy Council.

“It’s a critical way for people to reduce their power prices but also make a contribution to cutting their emissions.”

Mr Thornton said the average solar system now costs about $3000 or $4000.

The scale of rooftop solar means that on October 17, it accounted for almost 40 per cent of the demand in the National Electricity Market.