Origin Energy will go ahead with the second phase of its big battery project on the site of Australia's largest coal-fired power plant.
Announcing the $450 million investment decision on Thursday, Origin said the combined energy storage of the stage one and stage two batteries at Eraring in NSW would be more than two gigawatt hours, which would help to keep the electricity grid stable.
Origin's head of energy supply and operations Greg Jarvis said energy storage would play an important role in the changing grid by helping to firm up supply from wind and solar farms and support more renewable energy coming into the system.
The Eraring site near Lake Macquarie hosts Australia's biggest power station, which continues to supply a quarter of NSW's electricity under a deal with the state government to delay its closure until 2027.
"Eraring is a strategic site with high quality connection infrastructure. Confirmation of the second stage of the Eraring battery development is a key next step as we look to transform the site," Mr Jarvis said.
The second stage of the Eraring battery will be more than four hours duration and capable of absorbing excess solar generation during the day to support evening peak demand, he said.
It will add a 240MW battery to the two-hour duration 460MW battery already being built at the site, which is expected to come online by the end of 2025.
With batteries set to do the heavy lifting in firming up the grid, Origin has now committed to more than 1.5GW of batteries, including one at the Mortlake gas-fired power plant in Victoria.
Origin also inked a long-term deal with Quinbrook Infrastructure Partners in July for offtake from the Supernode battery that is under construction in Queensland at the central node of that state's electricity network.
The Quinbrook-owned Supernode site is the last non-flood-prone land adjacent to the South Pine central node.
In NSW, works on the second stage at Eraring are scheduled to begin early in 2025 to come online in the first three months of 2027 - well before the ageing coal plant is scheduled to be decommissioned.
Finnish technology group Wärtsilä, which also worked with AGL at the completed Torrens big battery project in South Australia, will supply battery equipment for stage two of the Eraring project.
Design and construction services would be provided by Enerven Energy Infrastructure.
