An $80 million maintenance overhaul and an increased ability to power down when renewables swamp the market have set up Origin Energy’s giant Eraring coal power station to battle through its final years before the NSW Central Coast site transforms into a battery storage hub.

Originally run around the clock at near-constant levels, the 2880-megawatt generator – the country’s biggest – now chases the market, powering up or down to suit price swings in the National Electricity Market (NEM) that can fluctuate every five minutes.