Coal supply issues have resulted in Mt Piper scaling back its operations, owner EnergyAustralia announced on Wednesday, September 4.
EnergyAustralia said in a statement that it would operate the Mt Piper power station "in coal-conservation mode" between September and the end of November.
The aim would be to have the plant running at full capacity "when it is needed most over summer".
EnergyAustralia Executive Energy Liz Westcott said there would be no impact to jobs as the plant, which was currently facing an acute coal shortage.
The plant would use the down-time to do major maintenance works and build its stockpile, she said.
Mt Piper would remain ready to come back online to meet periods of high demand.
"We've investigated every other option, but this is the only one we can responsibly take," Ms Westcott said.
"Our priorities are to protect jobs and have the plant ready to run at full capacity during the peak demand of summer.
"We're exploring long-term remedies to the plant's supply problems, including a rail unloader which would allow Mt Piper to receive coal from other multiple coal mines.
"Right now, we're working with the New South Wales government and Centennial Coal, owner of the sole mine supplying Mt Piper, on alternate sources of coal, to ease constraints on the power station."
The statement said Mt Piper has managed significant issues with coal quality and volumes from the Springvale mine for the past few years.
To conserve coal, Mt Piper has generated around 40 per cent less electricity so far in 2019 compared to the same time last year.
Mt Piper is responsible for supplying 15 per cent of the State's electricity.