By Sudarshan Varadhan and Christine Chen
For 64-year-old transport worker Paul Tyler, who lives 160 km (100 miles) north of Sydney, installing solar panels had long been financially out of reach.
Australia's federal battery subsidy changed that, helping him cut upfront costs by 30% and install 18 solar panels and a 28-kilowatt-hour battery this year for A$9,000 ($6,247.80).
"I would never have afforded it if not for the subsidies," he said, adding that his monthly power bill dropped to around A$50 from A$275.
Tyler is one of the hundreds of thousands of Australians driving a battery rush that is boosting new solar connections and upgrades to larger panels to store more power.
The rooftop solar boom shows how countries stifled by transmission line logjams can continue reducing emissions, analysts say.
Australians spent a collective A$8.69 billion on home batteries in the five months through May, according to a Reuters calculation based on average prices on the Solar Choice website and installations data from consultancy SunWiz.
The splurge followed the government's decision in December to more than triple the value of its Cheaper Home Batteries Program announced last July to A$7.2 billion over four years.
The 7.7 gigawatt-hours in home installations between January and May exceeded uptake in the previous six years combined, SunWiz data showed, benefiting battery makers including Tesla NASDAQ:TSLA, BYD SZSE:002594, Sungrow SZSE:300274 and Fox ESS.
'SIGN OF WHAT THE FUTURE CAN LOOK LIKE'
"Lightweight" regulations reduced installation costs to a third of U.S. levels, helping one in three Australian homes adopt rooftop solar - the highest penetration in the world, according to a report by the CHARGED initiative.
Now, batteries are driving rooftop solar installations even higher, with SunWiz forecasting 2026 additions to surpass a 2021 peak and surge 41% to a record 4 GW - equivalent to more than two-thirds of the country's large renewable additions in 2025.
"It's a sign of what the future can look like. The solution we need most is already above people's heads, on their roofs," said SunWiz Managing Director Warwick Johnston.
Australia's coal-fired output, its main power source, has declined for 10 straight months amid the solar resurgence, according to monthly National Electricity Market data through June from the OpenElectricity platform.
LIGHT BILLS BECOMING A LIFESTYLE CHOICE
Stored power is increasingly meeting evening demand and reducing the case for some new transmission lines, said Commonwealth Bank of Australia energy economist John Oh. Australia's energy market operator expects pooled home batteries to eliminate A$5 billion in grid-scale battery investments.
"Distributed energy driven by batteries is a great alternative to circumvent delays in grid transmission buildout, and this can be replicated across the Asia-Pacific," said Climate Energy Finance Director Tim Buckley.
Higher evening supply from home batteries to the grid is also helping lower wholesale prices, said Brian Spak, general manager of advocacy and policy at Energy Consumers Australia (ECA).
"Even people who don't have batteries receive benefits from their neighbours taking up the program," he said.
Still, nearly half of Australian households cannot access solar or batteries because they rent, live in apartments or earn less than A$50,000 a year, according to ECA.
"Seeing all the houses around you with solar panels, but not having access to solar panels on yours is a bit annoying," said Dale Best, a 25-year-old engineer who rents a house with three others in southern Sydney.
But for homes with solar, storage is giving occupants more control over costs as they choose when to use and export power instead of paying rigid retail tariffs, said Geoff Eldridge, principal adviser at energy consultancy Global Power Energy.
"The battery is not the revolution by itself. The revolution is that electricity is moving into everyday household decisions."
($1 = 1.4405 Australian dollars)