First stage of Australia’s biggest battery starts operations in shadow of biggest coal plant

The first stage of what will be – at least for a time – the biggest battery in Australia has started commercial operations, in the shadow of the country’s biggest coal generator.

The start of commercial operations of the 460 MW/1770 MWh stage 1 Eraring battery was announced on LinkedIn last week by Greg Jarvis, the head of energy operations at Origin Energy, which also operates the neighbouring 2.88 gigawatt Eraring coal fired power stations.

Origin has been adjusting the dimensions of the Eraring battery as the price of battery storage continues to plunge and as the market opportunity for big batteries expands, particularly for big utilities such as Origin with a large legacy portfolio to protect and manage.

The first stage was initially sized at 460 MW and 1070 MWh when first announced in early 2023, but has been boosted by an extra 700 MWh of storage that effectively transforms it from a two-hour battery to a four hour battery.

Another stage, comprising 240 MW and 1030 MWh was announced in 2024, and last year Origin decided to add an extra 360 MWh – at an additional cost of just $80 million – transforming that part of the project from a four hour battery to a near six-hour battery. That stage 2 battery is due to be commissioned in early 2027.

All up, the Eraring battery complex will total 700 MW and 3,170 MWh when complete, overtaking the Collie batteries in Western Australia (Neoen’s 560 MW and 2,240 MWh and Synergy’s 500 MW and 2,000 MWh installations that are now operating).

The Eraring battery will vie with Quinbrook’s Supernode battery as the biggest in the National Electricity Market – although, for the moment, Eraring stage 1 takes that title.

Jarvis says the Eraring battery will allowing Origin to store electricity produced in the daytime from sources such as solar, and “release energy when it’s needed most”, most likely in the evening or morning peaks.

It is the company’s first big battery, and the first big asset of any type it has built since announcing in 2022 the planning “early closure” of the Eraring coal plant in August, 2025, since delayed to August, 2027 and now likely to be pushed back further.

Hear our interview with Origin CEO Frank Calabria in this episode of our weekly Energy Insiders podcast: Energy Insiders Podcast: Origin CEO Frank Calabria’s big energy vision

Origin is also building the Mortlake battery in Victoria, sized at 300 MW and 650 MWh, and the 240 MW, 480 MWh Summerfield battery in South Australia. It also has contracts with large parts of the Supernode battery complex

“This milestone is the culmination of a huge amount of work from our teams and contractor partners Wärtsilä, Enerven, Jacobs, Lumea and Transgrid to build the asset on time and under budget, integrate it into our portfolio, and develop the systems needed to bid it into the market,” Jarvis said in his LinkedIn post.

“Our Eraring battery is the largest approved battery energy storage system in the Southern Hemisphere – reinforcing the site’s role as critical infrastructure at the centre of Australia’s energy system for decades to come.”

See Renew Economy’s Big Battery Storage Map of Australia for more information.

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