Written

For

The

Australian

-

Home

battery

boom:

we

crunch

the

numbers

to

see

if

it’s

worth

it

More Australians applied to install home batteries in three months than in the entire previous year. That's not a trend — that's a stampede.

The trigger is the federal government's Cheaper Home Battery program, which kicked off on July 1 and slashes 30 per cent off the cost of a home battery system. With $2.3bn allocated and industry warnings that the pot could be empty by next year, homeowners are rushing to lock in the discount before it disappears.

So I ran the numbers on my own household to see if it actually stacks up.

We chew through about 1000kWh a month — heat pump for the pool, EV charging, ducted air-con, and three kids with an aversion to light switches — costing around $300 a month. I already have 12kWh of solar exporting 1000kWh back to the grid, but at 4c per kWh the feed-in tariff barely covers the daily service charge. Add the emerging "sun tax" penalising exports at peak times, and the case for capturing that energy in a battery becomes compelling.

A 35kWh battery to go off-grid would cost about $15,000 after the rebate, with a five-year payback and roughly 10 years of profit after that. Go bigger — max out at 50kWh for $25,000 — and you unlock "virtual power plant" income of about $2000 a year plus a $1500 NSW incentive, dropping the payback to just over four years.

I've paid my deposit. But a warning: quotes I received for identical systems ranged from $25,000 to $45,000. Some installers are absolutely price-gouging in this frenzy, so get at least three quotes before you sign anything.

For once, the numbers on renewables genuinely stack up — but only if you move before the funding runs dry and only if you don't overpay for the install.