Twenty-Five Years of Rooftop Solar: Who were the Pioneers?

It has been 25 years since the Renewable Energy (Electricity) Act 2000 established the market for renewable energy certificates (RECs), which came into effect on 1 April 2001. For residential rooftop solar, the Act enables the Small-scale Renewable Energy Scheme (SRES), which provides financial incentives through Small-scale Technology Certificates (STCs). These certificates reduce the upfront cost of solar systems for households. The Clean Energy Council (CEC) supports this scheme by accrediting installers and approving solar products; only systems installed by CEC-accredited professionals using CEC-approved equipment are eligible for STCs. Together, the Act and certificates have played a key role in driving rooftop solar adoption across Australia.

The past quarter-century has witnessed a remarkable transformation of Australia's energy landscape. Clean Energy Regulator data, published since April 2001 when there were just a relative handful (118) of pioneering rooftop solar installations, shows that by March 2025, over four million Australian households are now generating their own electricity. In this article, we look at distinct patterns in how different regions have embraced small-scale PV technology. Before we examine the divide between "high installation" and "low installation" areas, we will look at the rooftop technology adoption curves across Australia to identify pioneering regions and define the timeframe that includes “pioneers.”

Figure 1: Rooftop Solar Technology Adoption Curve in Australia

Source: Adoption categories based on the Technology Adoption Lifecycle, popularized by Everett M. Rogers in Diffusion of Innovations (1962).

Figure 1 applies the Technology Adoption Lifecycle to rooftop solar technology uptake across Australia, classifying the timeframe when regions reached key adoption milestones. Classification of the adoption phase is derived from cumulative rooftop PV installation data (up to March 2025), using defined cut-off dates aligned with typical adoption curve thresholds. Drawing on the theory, rooftop solar adoption in Australia took over nine years to reach just 2.5 per cent of dwellings (from April 2001 to October 2010), marking the “Innovators” stage. That’s roughly 240,000 rooftop solar installations out of approximately 9.1 million dwellings across Australia. However, adoption accelerated, taking only six more years to reach the “Early Adopters” phase by October 2016. As of April 2025, rooftop solar is installed on about 40 per cent of Australian dwellings, indicating the transition into the “Early Majority” stage. This reflects how new technology gains momentum once early success is visible and barriers to adoption fall.

While the Technology Adoption Lifecycle provides a useful timeframe for understanding rooftop solar uptake, the initial analysis reveals that a large number of postcodes (nearly 90 per cent, or 2,530 postcodes and 485 Local Government Areas [LGAs]) registered installations by October 2010, technically classifying them as "Innovators." This broad classification masks important regional differences in growth patterns over time. To extract more meaningful insights, we focus on the top 5 per cent of regions (24 LGAs) with the highest number of installations by October 2010. These regions alone accounted for more than a third (35.1 per cent) of all rooftop solar systems installed during the Innovator phase (Table 1). This highlights a strong early concentration of adoption in a small number of pioneering areas. Although by March 2025 their combined share slightly declined, indicating some broadening of adoption, these regions continued to be strong adopters of rooftop solar.

Table 1: Share of rooftop solar householders classified as “Innovators” (installed by October 2010)Source: Clean Energy Regulator data, Australian Energy Council analysis, data as of 24 April 2025

Innovators with Sustained Momentum

Among these top 24 LGAs, Brisbane stands out significantly, representing 4.9 per cent of all installations by 2010 and increasing its share to 5.2 per cent by March 2025. Brisbane has seen the highest uptake of any LGA. Other LGAs, such as Gold Coast and Moreton Bay, also experienced growth in their national share, rising from 2.8 per cent to 3.3 per cent and 2.4 per cent to 3.0 per cent, respectively. This trend suggests that several of the earliest adopters not only led the initial wave but continued to outpace the national average in installation growth.

Most LGAs experienced modest changes in share over time, indicating a degree of consistency in their contribution to national totals. For instance, Blacktown in New South Wales maintained a steady share (1.3 to 1.4 per cent), as did Fraser Coast in Queensland (1.2 to 1.2 per cent) and Wanneroo in Western Australia (1.5 to 1.4 per cent).

Pioneering Regions Reaching Plateau

Conversely, a number of LGAs that were prominent in the early period saw a decline in their relative share by March 2025. For example, Queensland’s Sunshine Coast fell from 2.7 per cent to 1.5 per cent, Redland (NSW) from 1.5 per cent to 0.8 per cent, and Parramatta (NSW) from 1.2 per cent to 0.7 per cent. These decreases suggest that while these areas were early adopters, installation growth in other LGAs has since caught up or surpassed them, diluting their overall share. While the national uptake has become more distributed over time, many of these LGAs maintained a prominent role in the overall solar landscape.

Some LGAs in New South Wales (Ballina, Northern Beaches, Parramatta, Tweed, and Wollongong), Victoria (Brimbank), and Western Australia (Kalamunda) have decreased their share of total installations over time and no longer rank within the top 5 per cent by March 2025, as other regions have adopted more solar. As a result new regions have emerged as leaders. LGAs such as Ipswich and Townsville in Queensland, Port Adelaide Enfield in South Australia, Cardinia, Casey, and Wyndham in Victoria, and Rockingham and Swan in Western Australia have seen strong growth, rising into the top 5 per cent of rooftop solar adopters by the end of March 2025. The table below shows the changing dynamics in solar uptake and trendlines, with emerging growth areas surpassing some of the early leaders.

Table 2: Top 24 LGAs classified as “innovators” with highest number of rooftop installations

Source: Clean Energy Regulator data, Australian Energy Council analysis, data as of 24 April 2025

Late Entrants

At the other end of the adoption spectrum, a number of LGAs had no rooftop solar installations prior to October 2010, placing them outside the "Innovator" category entirely. These include regions such as Bland (NSW), MacDonnell and Victoria Daly (NT), Napranum and Winton (QLD), and several remote LGAs in Western Australia. The uptake has been slow and dispersed. By March 2025, their cumulative contributions remain minimal, with a combined share of less than 0.1 per cent of total installations nationally. This pattern likely reflects several factors that might have delayed solar adoption in these regions, such as:

• Remote/rural locations with sparse populations.
• Potentially challenging grid connectivity issues.
• Economic factors specific to these communities.

Table 4: Late Entrants

Source: Clean Energy Regulator data, Australian Energy Council analysis, data as of 24 April 2025

Conclusion

Understanding these adoption patterns provides useful insights for industry stakeholders planning the next phase of market engagement. Innovator regions identified in this analysis are likely to continue to have high growth potential for solar and solar-related products. However, many of these top early entrants are now nearing saturation points, signalling a shift in opportunity from new installations toward system upgrades, battery storage, and performance optimisation. As the market matures, it will be important to track whether these early solar champions are also leading in the uptake of complementary technologies such as home battery systems and electric vehicles. Their trajectory may offer a preview of how and where integrated, consumer-led energy systems will evolve across Australia.

*This article is an extract from the Australian Energy Council's Solar Report: First Quarter of 2025.