Home batteries in a single western Sydney postcode have reached a combined storage capacity of 156 megawatt-hours — twice that of the nearby Wallgrove grid battery.

Here's what to know

With 4,202 home batteries, Riverstone and Marsden Park's postcode 2765 led Australia in storage capacity added since July 2025, RenewEconomy reported.

The result comes from energy analyst Kanav Verma's ranking of 2,473 postcodes using Clean Energy Regulator data. The 78-megawatt-hour Wallgrove battery is about 10 miles away in Eastern Creek.

Melbourne's Tarneit–Truganina postcode 3029 and Werribee–Point Cook postcode 3030 placed third and fourth in Verma's ranking, with 134 and 99 megawatt-hours, respectively. 

Kellyville–Rouse Hill's postcode 2155 ranked second with 137 megawatt-hours.

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More background

The Australian Energy Market Operator found that sampled households pairing rooftop solar with batteries used about 75% less grid electricity during the evening peak, from 4 p.m. to 9 p.m., than households with rooftop solar alone.

Along with milder conditions and a shift toward more daytime electricity use, this change helped reduce the National Electricity Market's evening peak demand from the grid.

The share of time when utility-scale batteries determined wholesale prices through charging and discharging rose from 18% to 48% over a year, reaching the higher figure in the September quarter, AEMO data showed.

At its debut, South Australia's Hornsdale "Big Battery" held 194 megawatt-hours of storage. 

The combined home batteries in the two leading postcodes exceed that capacity, totaling 293 megawatt-hours.

What's being done?

Verma raised the question of whether network planners are accounting for suburban storage in Sydney's west and Melbourne's west. 

To understand the resulting changes in electricity demand, AEMO is examining battery use among sampled households.

For households like those in the analysis, storing rooftop solar for evening use can reduce the amount of electricity they need to buy, potentially lowering bills. Those savings depend on electricity rates and installation costs.

Beyond the potential financial benefits, batteries with suitable equipment and configuration keep essential devices running during grid outages. They also support energy independence, such as living off-grid.

For people seeking a smaller backup option, Pila offers a plug-and-play alternative at a substantially lower price than whole-home backup systems.

"Same amount of storage. One is a grid asset. The other is invisible to the grid, unless someone pools them together," Verma wrote on LinkedIn, describing the postcode's battery capacity.

Where can I learn more?

Household and community batteries are gaining ground well beyond Sydney's suburbs. These stories cover Australia's battery boom and pooled batteries supporting American grids.

• Australia's home battery installations outpaced rooftop solar growth as rebates helped drive record uptake.

• In Vermont, 5,500 leased home batteries became the state's biggest power source.

• In Australia, large home batteries made electricity feel "free," prompting families to use more.

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