Rooftop solar panels in the South-West Interconnected System (SWIS) in Western Australia are now producing as much energy as the state's largest power turbine, according to research from Curtin University.

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SWIS stretches from Kalbarri north of Perth to Ravensthorpe in the state's south, taking in the Perth metropolitan area.

Curtin University sustainability professor Peter Newman said 20 per cent of homes across the grid have rooftop solar panels installed.

"We are in the extraordinary position of saying that Perth [SWIS] now has rooftop solar as the largest supplier of electricity, it's the biggest power station in WA," he said.

"It's nearly 500 megawatts and it's growing rapidly, by 2020 we could have half of Perth's [SWIS] households with rooftop solar."

SWIS, which includes coal, gas, wind and solar generation, has the capacity to produce 5,300 megawatts of power, but it only used roughly two thirds of that at its peak in 2014/2015.

Not including solar, coal makes up about 50 per cent of WA's energy production mix, while gas represents 42 per cent and wind 6.3 per cent.

Professor Newman said the state's electricity utilities needed to rapidly adapt to the growth in solar.

"They didn't predict it, they have all these contracts for coal and gas that go 20 or 30 years and they have even got an old power station out of mothballs, fixed it up, but never turned it on," he said.

"Despite the boom times we actually reduced our power consumption during this period because people are just not needing it if you've got the PV's [photovoltaic] on the roof."

Energy utility Synergy has been contacted for comment.

Batteries to drive solar boom

Rooftop solar's biggest weakness has been its inability to supply power once the sun sets.

This can be addressed with the installation of large battery systems that allow households to store solar energy for use in peak periods.

Clean Energy Council policy manager Darren Gladman said until recently battery storage systems had been too expensive for the average consumer.

He said household batteries would become increasingly common with big producers like billionaire entrepreneur Elon Musk's company Tesla entering the market.

"In 2016 the onset of batteries and entry of Elon Musk to the market is going to really change the way we think about energy," he said.

"We are not just going to think about producing energy from solar, but producing energy and storing it."

Mr Gladman said Australia would become a global leader in the rollout of battery technology.

"Because we've got so many households with solar on the roof, reasonably high power prices and great sun of course, it means we are a prime market," he said.

"So that makes [us] one of first markets the likes of Elon Musk, but also other companies that sell batteries, are targeting."