Largest battery in Australia to be built at ageing NSW coal-fired power plant ABC Business 12/01/2021 By business reporters Gareth Hutchens and Emilia Terzon An energy provider's plan to build Australia's largest battery is the latest development in a quickly transitioning energy market. Origin Energy has unveiled plans to build a giant 700-megawatt capacity battery at its coal-fired power plant in Eraring, south of Newcastle, in the New South Wales Hunter region. If built, Origin said it would have capacity to supply that power to the grid for four hours. If the plan goes ahead, the battery would be more than four times larger than the 150-megawatt Tesla battery in South Australia.