The Eraring BESS (battery energy storage system) is set to become one of the largest in the Southern Hemisphere, with Origin Energy approving the third stage of the project, including the addition of further storage capacity.
The third stage of the Eraring battery will add 700MWh to the 460MW/1070MWh first stage already under construction, increasing its dispatch duration to approximately four hours.
With the 240MW/1030MWh second stage of the project also under construction, the combined energy storage of the Eraring battery will be 700MW/2800MWh, making it one of the largest battery energy storage systems in the world.
Origin Energy said this latest investment in the battery at the Eraring Power Station site represents a further acceleration in the utility’s strategy to grow storage in its portfolio to help keep the grid stable as it supports increasing growth in variable renewable energy.
Origin has committed to 1GW of large-scale battery capacity across its projects at Eraring and Mortlake Power Station in Victoria, along with tolling agreements for the offtake from Queensland’s 500MW Supernode battery, which will begin to come online in the first half of the 2026 calendar year.
Origin’s Head of Energy Supply and Operations, Greg Jarvis, said, construction of the third stage of the Eraring battery further increases Origin Energy’s energy storage footprint and represents another significant step in its ambition to lead the energy transition through cleaner energy and customer solutions.
“The scale of this project is impressive. The site, at more than 17ha, is equivalent in area to 24 soccer fields and once complete, it will host more than 2000 individual battery enclosures and some 180km of cabling.”
Mr Jarvis said at 2800MWh, when cycled once a day, the Eraring battery will dispatch enough energy to power more than 150,000 New South Wales households annually, helping to firm variable supply from wind and solar.
“Transforming the Eraring site to play an important role in contributing to the reliability and security of electricity supply as we progress through the energy transition is a priority for Origin. Upon completion, Australia’s largest power station will be host to the nation’s largest approved battery storage system, cementing Eraring as a critical piece infrastructure at the heart of Australia’s energy system for decades to come,” Mr Jarvis said.
“The global scale of the battery storage system under construction and the incredible work our highly skilled teams and contractors are undertaking is something the region can be incredibly proud of.”
Stage three is anticipated to come online alongside stage one at the end of calendar 2025. Stage two is anticipated to come online in the first quarter of the 2027 calendar year.
Origin Energy said alongside the large-scale battery under construction at Mortlake Power Station in south-west Victoria, this third stage takes its committed investment in owned storage in the portfolio to approximately $1.7 billion.
The grid-forming battery at Mortlake, adjacent to the largest gas-fired power station in Victoria, is expected to come online in late 2026.
Origin Energy said Eraring delivers up to a quarter of electricity supply in New South Wales. The 40-year-old plant is scheduled to close in August 2027, as part of an agreement with the New South Wales Government to support security of supply through the transition and while there remains uncertainty regarding the timing of transmission, renewables and firming infrastructure coming online.
