Australia is on the cusp of a major shift in solar battery adoption — one where more batteries may be installed each year than new PV systems. This tipping point would mark the moment when the battery attachment rate exceeds 100%.
But how is that possible?
What is Battery Attachment Rate?
Traditionally, the battery attachment rate referred to the percentage of new PV systems that included a battery at the time of installation.
For example, an attachment rate of 25% means one in four PV installs included a battery.
But the market has evolved.
Today, a large and growing share of batteries are being retrofitted to existing solar systems — meaning the concept of attachment rate needs to adapt.
Retrofits Are Now the Norm
Australia has installed 4 million PV systems since 2008, but less than 3% of them have batteries.
That’s changing fast.
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In 2024, over 50% of battery installations were retrofits — added to existing PV systems without upgrade.
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Another 16% were coupled with systems where the PV was expanded.
Retrofit installations are likely to dominate for the next few years, especially as solar retailers revisit their existing customer bases. Some are already seeing this shift in their business models.
From Field Research: A Shift in Language
While researching the 2025 SunWiz Battery Market Report and preparing our Top Battery Retailer Award, we interviewed dozens of retailers.
One quote stood out:
“I’m starting to refer to my PV attachment rate.”
This wasn’t just a clever turn of phrase. It reflects a real shift: for some companies, batteries now outnumber PV installs in their job pipeline. Not due to standalone systems, but because:
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1/3 of their work is battery retrofits
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1/3 is batteries with new or expanded PV
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1/3 is PV-only installs
This is the new normal — and it’s spreading.
2024 Snapshot: 22.6% Battery Attachment Rate
In 2024, Australia installed 226 energy storage systems (ESS) for every 1,000 PV systems — an attachment rate of 22.6%, up from 17% in 2023.
That’s a strong jump — but we’re still a long way from national attachment rates over 100%. With ~300,000 PV installs annually and only ~70,000 battery installs in 2024, battery numbers haven’t caught up yet.
What Could Push Us Over 100%?
The new federal battery subsidy will play a major role in accelerating uptake. However, for battery installations to reach PV parity:
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Installer capacity must scale significantly
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Retailer business models must shift toward retrofit targeting
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Consumers need clear economic signals to invest
We’re not quite there yet — but many individual retailers will soon pass the 100% mark, if they haven’t already.
Get the Full Picture
The 2025 SunWiz Annual Battery Market Report explores this trend — and many more — in depth. It includes:
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Battery vs PV installation volumes and forecasts
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State-by-state analysis of retrofit vs new
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Market share breakdowns
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Insights from top-performing retailers
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And a detailed outlook on where the market is heading
📘 Position your business for what’s coming next.
👉 Purchase the report here