The Turnbull government will seek expert advice on AGL's new electricity generation plan after the energy giant rebuffed the government and confirmed it would close its coal-fired Liddell power plant.

The company believes it can meet the energy shortfall and reduce emissions through a multi-phase development of gas, wind and solar plants, while proceeding with the long-slated closure of Liddell in 2022.

The Liddell power station, in Muswellbrook NSW, will be decommissioned by 2022. Credit:AAP

Prime Minister Malcolm Turnbull, who has made electricity supply and power prices a key electoral issue, had implored AGL to consider extending the life of the ailing power station or find a willing buyer.

He said yesterday AGL's plan was "not at all" a rebuke of the government and it will be assessed by the Australian Energy Market Operator by mid-February.