Sydney’s Renewable Potential: Unlocking 21GW Through Rooftop Solar

A recent analysis suggests that metropolitan Sydney could become a powerhouse of renewable energy, with the capacity to produce up to 21 gigawatts (GW) of clean electricity through the installation of rooftop solar systems.

The study, conducted by engineering firm Arcadis in collaboration with the Committee for Sydney, Ausgrid, Endeavour Energy, and Arup, explores the concept of transforming Sydney into a Renewable Energy Zone (REZ). This metropolitan REZ could tap into the vast, underutilized surface area of residential, commercial, and industrial rooftops across the city's 12,368 square kilometers.

If fully realized, this initiative could supply approximately 75% of Sydney’s total annual electricity consumption—an impressive figure given that the city accounts for nearly half of the entire state’s power demand.

Alan Brookes, CEO of Arcadis, emphasized the potential of such a coordinated effort. “By harnessing the largely unused rooftop solar capacity and integrating battery storage, we can pave the way for a greener, more robust, and fairer energy system for Sydney’s residents,” he said.

New South Wales: A Leader in REZ Development

Across New South Wales, multiple REZs are already underway as part of a broader transition within the National Electricity Market (NEM). The Central-West Orana zone is set to be the first to enter construction, and the state is planning at least four more.

Breaking from tradition, New South Wales is exploring urban-focused REZs, like the one proposed for Illawarra, which relies on distributed generation including rooftop solar, neighborhood-scale battery systems, and virtual power plants (VPPs)—a model that aligns closely with Sydney’s potential transformation.

In some suburbs, local generation already covers around a third of the energy consumed. Areas such as Riverstone, Marsden Park, Oakville, and Box Hill contribute over 100 megawatts (MW) of decentralized energy, while districts like Hornsby and the Northern Beaches show the highest energy self-sufficiency ratios. Currently, around 3GW of rooftop solar is installed across Sydney, meeting about 10–12% of its electricity needs.

Expanding solar coverage alongside community-based battery storage could significantly enhance this performance, helping manage surplus energy and redistribute it across local networks—a topic covered in depth on Energy-Storage. news.

The report describes this as a pivotal opportunity, particularly with aging coal plants scheduled for retirement. A well-planned Sydney REZ could be key to ushering in new forms of renewable power generation.

Industrial Rooftops: A Largely Untapped Resource

Australia’s rapid uptake of residential solar has helped the country achieve one of the highest solar capacities per capita globally. Expanding this momentum into the commercial and industrial sectors could unlock even greater potential.

The report notes that industrial buildings, with their expansive roof areas and relatively low power consumption, are ideal candidates. In some cases, these facilities could generate up to five times their own energy needs. Despite this, rooftop solar installations are usually limited to covering only on-site demand. This conservative sizing prevents asset owners from leveraging potential revenue by feeding surplus electricity back into the grid—a limitation that could be addressed through the installation of small-scale battery systems.

Often, just 10–20% of an industrial roof’s surface is enough to cover current electricity needs. Yet with the right infrastructure, these buildings could become net energy exporters.

On the other hand, high-rise commercial and residential buildings typically have limited rooftop space relative to their energy usage. These properties might only meet around 5% of their energy needs with solar, while medium-density and manufacturing sites could reach 15–20%. Standalone homes, however, can often meet 100% of their demand with rooftop solar systems.

Growing Momentum Behind Battery Storage in Sydney

Battery energy storage systems (BESS) are becoming an increasingly common addition to solar PV installations, enabling homes and businesses to store excess power and increase their energy independence.

According to the report, Sydney is currently witnessing a significant rise in BESS investments. This is largely driven by New South Wales’ battery rebate scheme, which recently merged into a broader virtual power plant (VPP) initiative.

In less than 12 months, approximately one in every 40 solar-equipped households in Sydney has added a home battery. Federal support is also on the way, with a AU$2.3 billion (US$1.5 billion) commitment through the Cheaper Home Batteries Program expected to further accelerate adoption.

Vehicle-to-grid (V2G) technology is another promising development. Because electric vehicles (EVs) have larger batteries than home systems, they can play a vital role in grid stability and energy storage. The report highlights that both EVs and electric buses could serve as integral components of Sydney’s clean energy future.