Battery installers are bracing for a busy period as households and businesses jump on Labor's election promise to discount energy storage.
Thirty per cent off the up-front price of batteries was a signature pledge of the returning Albanese administration, targeting cheaper power bills and the transition to clean energy.
Industry figures expect the battery subsidy program will be a priority given the fast-approaching start date of July 1.
Solar and battery installer 1KOMMA5° is confident the scheme will go ahead as promised and is applying the discount already in the expectation incentive costs can be claimed back once the program goes live.
"We foresee, effectively, a mad rush for installation from July 1 and this gives a chance for consumers to get the benefit and beat the rush," the Sydney-based company's brand director, Andre Scott, told AAP.
The catch is batteries purchased through the scheme can only be switched on after the upcoming start date.
Mr Scott said there was still a good argument to go early, with customers potentially facing installation backlogs once the floodgates officially opened.
Smart Energy Council chief John Grimes expects strong demand from the millions of households with rooftop solar already installed.
Their solar energy was being fed into the grid for "basically nothing" while residents were out during the day, he said.
"They always feel a bit miffed because they made an investment and that's just going to the energy company that's just making a profit by selling that to the nextdoor neighbour."
Bills savings could be meaningful.
Government modelling suggests a household with existing rooftop solar could save up to $1,100 off their power bill a year, or $2,300 if installing both solar and a battery at once.
For many, the sticking point for home batteries to date has been the up-front price and the long related wait for systems to pay for themselves through lower bills.
Low-cost loans and other models were in play, but Labor ultimately landed on an expansion of the small-scale renewable energy scheme that already subsidises rooftop solar.
For customers, it functions as a discount at the point of sale, with savings of $4000 on a typical 11.5kWh battery promised.
Scott Dwyer, the research director from University of Technology Sydney's Institute for Sustainable Futures, said there was a lot to like about the scheme.
Pre-approved supplier lists should stop customers ending up with dud products and discounts dwindling over time were sensible given the technology would inevitably get cheaper.
Dr Dwyer said the size of the incentive was well-calibrated and would make batteries "really attractive for a lot of people".
But one worry for him was workforce constraints, with electrical skills already in high demand.
"As the program ramps up, we'll start to get indications around if there's any bottlenecks," he said.
The scheme has faced criticisms of unfairness, with the federal opposition arguing only higher-income families would be in a position to cover the still-high price-tag on a discounted battery.
Dr Dwyer shared concerns that the better-off would benefit disproportionately, adding the government should think of ways to ensure renters and other groups were not locked out of the advantages of solar and batteries.
However, even those without batteries were expected to benefit from the scheme, he said, as more storage absorbing free solar from household panels for later use should take pressure off the grid during peak evening hours.
Mr Grimes pointed to modelling by the industry body that suggested a battery as small as 5-6kWh would cover about 90 per cent of all households for the all-important time-shifting of power from the middle of the day to the evening peak.
Households could snag a smaller battery for $2500 or less after the incentive.
"That's like a credit-card purchase," he said.
Stacking the federal incentive with state-based supports could improve affordability even further.
Labor has budgeted $2.3 billion towards the uncapped scheme, but Macquarie University economist Rohan Best said there was a risk it would go over, especially if people rushed to piggy-back off state government rebates.
"With around 3.5 million households with solar but not a battery, and others who will get both at the same time, the one million new batteries might be exceeded over a five-year period if stacked subsidies are very generous," he said.
Dr Best favoured a better-targeted, less-generous federal scheme - at least initially - to lower the chances of a budget blowout.
Means-testing would also make the scheme fairer and ensure poorer households took up the offer.
A better-targeted scheme could get batteries into more low-income households for direct savings, he explained, rather than the harder-to-quantify benefits of less demand on the grid at peak times.
