Australia’s biggest coal generator set to be replaced by the world’s biggest battery

Origin Energy plans to expand the Eraring battery precinct from 700 MW to 1,200 MW and from 4,300 MWh to 8,600 MWh. The additional 500 MW, 4,942 MWh stage, called Eraring North, will begin construction in 2028 and reach full operation in early to mid 2031. Once complete, it will be the largest battery installation in Australia, surpassing the 7,800 MWh system completed in Saudi Arabia last year. The expansion comes as Eraring coal power station, rated at 2.88 GW, faces closure in 2029, with Origin citing the shift from coal toward variable renewable energy as the driver for the battery investment.

Where this fits

This exemplifies the whole-system cost of a renewables-led transition. A single coal plant of 2.88 GW is being replaced by 1.2 GW of batteries rated to discharge for just seven hours at nameplate capacity. That mismatch, batteries cannot replace the annual firming that coal provided, means the NEM still depends on gas, imports from other states, and demand destruction when the sun sets and wind drops. The battery's 8,600 MWh of stored energy cannot be generated without wind and solar upstream, and Origin has not built new generation to charge it. The battery also locks Australia into the China supply chain for lithium-ion cells, where manufacturing is coal-fired and embedded emissions far exceed the per-megawatt-hour headline.

What it means

A 2.88 GW firm generator is being replaced by a 1.2 GW storage buffer that depends on other sources to fill it. The NEM's reliability will rest on gas, interconnects, and demand management, the high-cost, high-carbon backstop of a renewables-only architecture. Australia forgoes a low-emission, firm alternative: new nuclear would retire the same coal plant and leave no generation gap to fill.