It found electricity generated by rooftop solar jumped by a third in the past year alone to 8900 gigawatt-hours. That total is on a par with the annual output from the Liddell coal-fired power plant in the Hunter Valley that owner AGL plans to close in 2022.
Solar’s momentum – and potential – are being fanned by the policy impasse over energy, including the failure of the Turnbull government’s National Energy Guarantee.
“[There’s the] people’s desire for autonomy and control – particularly when we’ve had a long discussion about what we will do – but not a lot of action,” Renate Egan, chairwoman of the APVI, said. “The delay tactics we’re seen have actually caused the [solar] industry to grow.”
Ms Adams last month replaced her first set of panels – with about one kilowatt of capacity installed in 2009 – with as big a system as she could fit on her roof, at 5.6 kilowatts.
“I’m a second-generation solar [participant], and a first-generation battery one,” Ms Adams, said referring to the seven kilowatt-hour storage she included in her package.
All up, the system cost about $18,000 and was purchased through the Inner West Community Energy group, helping to give her confidence about the deal.
While household consumption patterns and the efficiency of panels will vary – such as from roof orientation and shading – most households can expect to recoup their expenditure on solar PV in about five years, the report commissioned by the Solar Citizens group found.
Storage, in Ms Adams’ case, will pay for itself in about 10 years, she believes.
While rooftop PV output meets only about 3 per cent of national electricity demand, the proportion can soar to 20 per cent on peak sunny days.
While about one in five Australian households have solar – surging past the 2 million mark last week – there is scope to add much more, the report said.
Total rooftop capacity – including commercial properties – now exceeds 10 gigawatts, including about 61 per cent of that on homes.
A spatial analysis indicates the nation’s housing stock alone can accommodate 43 to 61 gigawatts of solar PV, with up to four gigawatts on apartments, the report found.
Dylan McConnell, an energy researcher at Melbourne University, said “there’s a lot of policy and regulatory barriers to realising that potential”.
He noted that the recently re-elected Victorian Andrews Labor government had earmarked much of its support for 650,000 new solar systems to renters to help them enjoy solar’s benefits.
On the other hand, the challenges of a solar boom are “front of mind” for regulators such as the Australian Energy Market Operator, he said.
For one thing, it is harder for them to anticipate how mass-distributed solar panels may affect grid supply and demand than, say, large-scale solar farms.
“These are not show-stoppers, but they do need some serious thought,” Mr McConnell said.
Peter Hannam is Environment Editor at The Sydney Morning Herald. He covers broad environmental issues ranging from climate change to renewable energy for Fairfax Media.