The TL;DR:
Australia’s east coast power grid recently achieved a notable milestone, operating at 72.1% renewable energy for a 30-minute interval. This development marks a significant step in the nation's transition away from fossil fuels. However, the Australian Energy Market Operator (AEMO) has underscored the pressing need for substantial grid upgrades to sustain and further enhance the integration of renewable energy sources, such as rooftop solar and electric vehicles.
The record-setting performance on the east coast highlights the rapid progress in renewable energy adoption, with AEMO reporting a peak instantaneous renewable potential of 99.7%. This figure, had it been fully utilized, could have met nearly all of the grid’s demand during that period. Nonetheless, the achievement also draws attention to the existing limitations within the grid infrastructure, which require urgent attention to support the increasing dependence on renewable energy.
According to AEMO’s recent *Engineering Roadmap FY2025 Priority Actions*, the National Electricity Market (NEM) is consistently breaking records for renewable energy penetration. As of the financial year 2024, renewable sources—including distributed photovoltaics (DPV) and large-scale solar and wind—provided an average of 40% of electricity in the eastern states. In December 2023, South Australia’s rooftop solar alone met 101.7% of the state’s underlying demand during a 30-minute interval, setting a global benchmark for a grid of this scale.
Despite these achievements, the transition to a renewable-dominated grid presents several technical challenges. AEMO is focusing on integrating rooftop solar panels and electric vehicles into the grid, which is essential for increasing the share of renewable energy in the overall electricity supply. The Engineering Roadmap outlines 37 priority actions for FY2025 aimed at overcoming these technical barriers and accelerating the move towards 100% renewable energy.
AEMO's Chief Executive, Daniel Westerman, has emphasized the importance of grid preparedness, particularly during periods of high renewable energy generation. Westerman stated, "We are working closely with international peers and local industry to address operational and system security constraints, enabling us to harness more renewable energy for Australian homes and businesses."
AEMO has initiated a comprehensive engineering program to ensure grid stability as the contribution of wind and solar power continues to grow. This program includes efforts to reduce renewable energy curtailment and manage the operational transition as coal generators are phased out and replaced by renewable sources. In 2023, large-scale solar farms contributed 7% of electricity on the east coast, wind turbines accounted for 13%, and rooftop solar panels added 12%.
The widespread adoption of solar energy in Australia is evident, with over 3 million homes now equipped with solar panels. However, the influx of solar power during daylight hours, followed by a sharp decline in the evening, poses significant challenges for grid stability. AEMO projects that by 2050, 80% of Australian households will have solar panels, making the management of these stability issues increasingly crucial.
To address these challenges, energy ministers have approved a plan to standardize inverters, which convert solar-generated direct current into the alternating current used by the grid. These new standards are designed to ensure that inverters remain connected even during grid disruptions. Additionally, a consistent national framework for electric vehicles has been agreed upon, enabling them to feed power stored in their batteries back into the grid during periods of peak demand.
Earlier this year, a trial demonstrated that electric vehicles equipped with the necessary technology could detect grid disruptions and provide power back to the network. This capability is seen as a potential game-changer in maintaining grid stability as renewable energy penetration increases.
Western Australia’s South-West Interconnected System (SWIS) is also navigating a similar transition towards higher levels of renewable energy. The SWIS Engineering Roadmap, developed by AEMO, outlines the engineering actions required to operate the SWIS securely and reliably in a renewable-dominated environment. The roadmap identifies critical technical challenges such as maintaining system inertia, voltage control, and system strength, particularly as synchronous generators are gradually decommissioned. While there have been instances where the SWIS had enough renewable energy to meet total demand during periods of minimum operational demand, the grid still relies on fossil-fueled generators due to operational and economic constraints.
The SWIS roadmap highlights the need for coordinated efforts among AEMO, Western Power, governments, and industry stakeholders to ensure that the grid can function effectively with increasing levels of renewable energy. The ultimate goal is to enable 100% renewable generation while ensuring year-round stability and reliability. Key actions include developing new capabilities for voltage control, system strength, and ramping, as well as addressing challenges posed by minimum demand thresholds and operational transition points.
As Australia continues to move towards a more sustainable energy future, these developments underscore the critical importance of upgrading the grid and implementing supportive policies. AEMO’s Engineering Roadmaps for both the NEM and SWIS are essential steps in this journey, aiming to ensure that the grid can accommodate the increasing share of renewables while maintaining reliability and security.