Rooftop solar is a key driver of Australia’s renewable energy adoption, with the potential to provide about 60 gigawatts of clean energy and significant benefits to households if the technology is widely integrated across the country’s housing stock.
Despite the continued expansion of Australia’s rooftop solar energy capacity, it would be more effective economically and emissions-wise for households if their solar systems were combined with battery storage.
The latest figures from the Clean Energy Council’s biannual Rooftop Solar and Storage report covering July to December 2024 showed more than 300,000 rooftop solar systems were installed across Australia in 2024, for the fifth consecutive year.
Australia has installed over four million rooftop solar systems, collectively saving households and small businesses $6 billion in energy bills each year. In 2024 alone, more than 300,000 new systems were added, contributing to this significant reduction in energy costs.
The report showed rooftop solar had a generation share of 12.4 per cent in 2024, up from 11.2 per cent in 2023 and 6.5 per cent in 2020. Total installed capacity for 2024 was three gigawatts generated by 300,375 units.
This new capacity was complemented by the 1.1 gigawatts of commissioned large-scale generation projects over the same period.
Con Hristodoulidis, General Manager for Distributed Energy at the Clean Energy Council, said the results reinforced the importance of establishing a national battery rebate scheme to ease the upfront costs associated with adopting home batteries.
He said: “Rooftop solar saves an average Australian family $1,500 on their annual bill – this almost doubles if you add a battery.
“However, less than 5 per cent of rooftop solar owners have a battery storage system installed, despite its capability to save households up to 80 per cent for a combined solar battery system.
“In a cost-of-living crisis, it’s clear the upfront cost of purchasing a home battery, which averages around $12,000 – $15,000, is a barrier to entry for many people, and this is why we need a national battery rebate scheme.”
The Clean Energy Council’s ‘It’s time to back batteries’ campaign suggests a national rebate of up to $6500 per household could slash energy bills, as well as lowering system-wide costs for all energy users by $190 million by 2030.
Hristodoulidis added: “Home batteries provide flexibility for rooftop solar owners as to when their electricity is generated, used and stored.
“Batteries that are integrated into the grid (also known as orchestration, or virtual power plants) have the added advantage of supplying electricity to the grid when it is needed most, reducing costs for everyone and creating a more resilient energy system.”
The aim of the federal government’s recently introduced Cheaper Home Batteries Program is to balance electricity supply and demand across the grid. The scheme, in combination with potential state and territory initiatives, provides an incentive to install a small-scale solar battery, which needs to be coupled with a new or existing solar system.
Solar PV systems can be integrated into buildings in three ways, with the most common method involving the installation of commercially available modules on exterior surfaces, such as in retrofit projects where PV panels are added to rooftops.
Solar modules can also be integrated into building surfaces by being installed on façades or used as glazing in windows. Additionally, they can be fully integrated as building components, such as solar glass shingles.
Last year, researchers from the University of New South Wales’ School of Photovoltaic and Renewable Energy Engineering published a report assessing the rooftop solar potential of Australian housing stock, commissioned by non-profit Solar Citizens and the Australian PV Institute.
The study was also supported by the Australian Centre for Advanced Photovoltaics and received funding from the Australian Renewable Energy Agency.
The researchers estimated the total potential of rooftop solar across Australia’s housing stock to be approximately 61 gigawatts. As of June 2023, only about 15 gigawatts were installed, primarily on owner-occupied stand-alone and semi-detached houses.
This leaves approximately 46 gigawatts of untapped photovoltaic potential, which, if unlocked, could yield significant economic, social and environmental benefits for diverse Australian households in different types of dwellings.
These benefits include creating 48,000 jobs over five years, saving 5.7 million households without solar an average of over $1,300 annually, and generating total bill savings of $9.3 billion per year over 20 years, all from an initial investment of $9.8 billion per year for five years.
Unlocking the country’s rooftop solar potential would also reduce greenhouse gas emissions by 785,000 tonnes over 20 years.
The researchers noted that while Australia remained a global leader in residential solar deployment, with 35 per cent of all houses having installed solar, residential solar adoption was unevenly distributed across demographics.
They said: “Although the link between household income and solar installation is questionable, access to solar is dependent on dwelling type and tenure.
“More specifically, most residential solar is installed on owner-occupied houses, typically occupied by older residents with higher incomes.
“Installing solar on social and community housing, as well as incentivising installation on rental properties and apartments, could help ease the financial burden on some of Australia’s most vulnerable households, ensure more equitable access to renewable energy, and contribute significantly to the urgent decarbonisation of the electricity system.”
Previous studies estimated Australia’s total rooftop solar capacity by planning zone. The new research employs a similar methodology, incorporating updated data and assumptions.
In particular, it builds on prior research by combining a new, granular dwelling-level solar potential assessment of residential buildings across the City of Sydney with the City of Melbourne’s analysis used in previous reports.
The research also includes a detailed analysis by housing tenure and dwelling type to identify potential opportunities for effective policy intervention across Australian states and territories.
