AGL Energy takes FID on 500MW Tomago BESS in Australia

Australia-based energy company AGL Energy has announced the final investment decision (FID) on the 500MW/2,000 megawatt hours (MWh) Tomago battery energy storage system (BESS) in Newcastle, New South Wales.

The total construction cost of the four-hour duration, grid-scale battery project will be A$800m ($518m).

The battery will be financed through AGL’s balance sheet, using operating cash flows and current debt facilities, which include green capital expenditure loans.

Construction of the battery will begin in late 2025, with operations to commence by late 2027.

The battery is projected to have a lifespan of 20 years.

AGL managing director and CEO Damien Nicks stated: “The final investment decision on the Tomago battery project marks yet another significant milestone in AGL’s delivery of its strategy and the transition and decarbonisation of its energy portfolio.

“Once operational, the Tomago battery will expand on AGL’s existing suite of grid scale battery assets and contracted capacity from third parties and further enhance our flexible asset portfolio.”

AGL has contracted Fluence to serve as the engineering, procurement and construction provider for the project.

Fluence will undertake the construction of the project as well as delivering ongoing service and maintenance.

The Tomago project will use Fluence’s Gridstack Pro, a utility-scale energy storage solution known for its optimised design and flexibility. This system will enhance grid reliability by offering grid-forming capabilities.

This initiative is the third collaboration between Fluence and AGL on large-scale battery systems.

Fluence previously completed the 50MWh Broken Hill BESS, while the 1,000MWh Liddell BESS is currently under construction.

Fluence Energy APAC senior vice-president and president Jan Teichmann stated: “This project strongly demonstrates our ongoing commitment to support AGL in their ambitious plan to deploy large-scale battery storage systems for a renewable energy future across Australia.

“Australia remains one of the most important storage markets globally, experiencing significant growth as the country accelerates its transition to renewable energy sources.”

In July 2025, AGL Energy acquired full ownership of South Australia’s virtual power plant (the SAVPP) from Tesla.

Established in 2018, the SAVPP is one of the largest virtual power plants in Australia.