Australia’s Path to a Wholly Renewable Electricity Network

Australia is making notable strides toward a transformative vision shared by environmental advocates globally: powering its entire electricity system exclusively with renewable energy sources.

Understanding the National electricity Market and Its Renewable Capacity

The Australian Energy Market Operator (AEMO) oversees the country’s main electricity infrastructure, including the National Electricity Market (NEM), which serves about 90 percent of Australians, excluding remote areas and Western Australia. At peak times,the NEM manages nearly 40 gigawatts of demand-surpassing the highest electricity consumption recorded in New York State. In recent years, AEMO has undertaken extensive studies to chart a course away from aging coal plants and the longstanding nuclear energy ban toward a grid fueled entirely by renewables.

Economic Drivers Behind the Coal Phase-Out

AEMO’s leadership stresses that the shift away from coal is grounded in economic realities rather than idealistic goals.As older coal-fired power stations reach the end of their operational lives, they are being replaced by more affordable energy options, primarily renewables paired with energy storage and improved transmission infrastructure. Some gas-fired plants will remain operational during winter months to cover periods when renewable output dips. This market-led transition underscores how financial incentives are accelerating decarbonization independently of regulatory mandates.

Current Renewable Energy Landscape and Future Targets

Renewable sources currently account for roughly 38 percent of Australia’s electricity generation, while coal still contributes about 44 percent, according to recent International Energy Agency figures. Projections indicate that by 2035, nearly 90 percent of coal generation will be retired, with a full phase-out possible by the late 2030s.

A landmark achievement on the horizon is Australia’s first full day without any electricity generated from coal-a milestone that could arrive sooner due to competitive market forces or unexpected outages in aging plants. This mirrors the United Kingdom’s experience, which celebrated its inaugural coal-free day in 2017 and fully retired its last coal plant by 2024.

Maintaining Grid Reliability in a Coal-Free Future

As fossil fuel plants exit,AEMO has identified essential infrastructure upgrades to ensure a stable electricity supply. The challenge now lies in deploying technologies capable of stabilizing the grid when large conventional generators are offline. These solutions must provide critical system services beyond simple energy delivery, such as frequency regulation and voltage control.

Leveraging Australia’s Vast Geography for Renewable Expansion

Australia’s expansive landmass-comparable in size to the contiguous United States but with only about 27 million residents-offers abundant opportunities for renewable energy deployment on a per capita basis. The country benefits from cohesive national market policies that encourage rapid adoption of clean technologies, unlike nations with fragmented regulations or entrenched utility monopolies.

This favorable policy habitat supports widespread access to affordable solar panels and wind turbines without protectionist restrictions common elsewhere. Such as, during a recent half-hour period, renewable energy penetration on the NEM exceeded 78 percent despite transmission bottlenecks limiting even higher output levels. South Australia frequently generates more renewable power than it consumes, exporting surplus electricity to neighboring states.

The Rise of Residential Solar Power

In addition to large-scale wind and solar farms and utility batteries, rooftop solar installations have become a cornerstone of Australia’s clean energy transition. Nearly five million households now produce their own electricity through photovoltaic panels installed on their roofs. on certain days recently, these residential systems supplied up to 60 percent of total demand within the NEM-a clear indicator of Australians’ commitment to distributed generation.

Tackling Technical Hurdles: Replacing Grid inertia

A key technical challenge in moving toward full renewables involves replicating synchronous inertia-the physical property provided by spinning turbines in traditional generators that helps maintain grid stability by smoothing out fluctuations in voltage and frequency.

“These rotating masses act like shock absorbers,” explains AEMO leadership. “They continuously dampen disturbances that occur across the network.”

The lack of sufficient inertia recently contributed to widespread blackouts in parts of Europe due to voltage instability-highlighting risks if these essential services are not adequately replaced as fossil plants retire.

Beyond Batteries: Innovative Approaches for Grid Stability

While battery storage can offer some ancillary services like frequency response, it cannot fully replicate fault current support needed for protecting equipment during electrical faults such as short circuits. One promising solution involves installing synchronous condensers-large spinning machines without combustion-that provide inertia independently from fuel consumption; however, constructing new units is expensive under current market frameworks that do not separately value these services.

Retrofitting Gas Turbines with Clutch Technology

A practical alternative gaining momentum is retrofitting existing gas turbines with clutches between their combustion engines and generators. This modification allows generator rotors to spin freely without burning fuel while still delivering vital inertia support-and keeps gas plants available as backup during periods when renewables underperform due to low sun or wind (“cold dark still” conditions). Over time, these units could transition from natural gas toward biofuels or green hydrogen as part of deeper decarbonization efforts.

“This decades-old technology is straightforward yet highly effective,” notes industry experts about clutch retrofits-which cost substantially less than building new synchronous condensers from scratch.

Exhibition Projects Prove Large-Scale Viability

A pioneering project at Queensland’s Townsville gas plant involves converting turbines into hybrid rotating stabilizers using clutch technology-the first retrofit of its kind worldwide according to engineers involved in the effort. Although installation took approximately eighteen months due to auxiliary equipment relocation onsite, this approach remains faster and more cost-efficient compared with constructing new synchronous condensers.

The Role of Long-Duration Energy Storage in Providing Inertia

Emerging storage technologies also contribute valuable rotational mass alongside energy capacity support. As an example, Canadian company Hydrostor is developing an underground compressed air energy storage facility near broken Hill-a remote Outback town known for its mining history and appearances in post-apocalyptic films like Mad Max II-with around 18,000 residents today.

• This facility stores compressed air within subterranean caverns created by excavation;
• The released air drives turbines capable of delivering up to 200 megawatts continuously for eight hours;
• The system offers local backup if grid connections fail while feeding clean power into wider networks otherwise;
• The technology employs conventional rotating machinery that adds necessary system inertia;
• A clutch mechanism helps meet regional stability requirements when operating independently from main grids;

A Collaborative Model Boosts Confidence in Transition Success

This project was selected following competitive assessments by Transgrid focused on ensuring system security under islanded operation scenarios-demonstrating how innovative clean technologies can replace critical functions traditionally provided by fossil assets rather than relying solely on residual gas plants for stability reserves going forward.

“There is a strong sense of optimism here,” reflects industry observers on Australia’s proactive approach toward addressing challenges head-on instead of being hindered by them.”