NSW safe from summer blackouts: premier

Unlike South Australia, the lights won't go out in NSW even when air conditioners lean heavily on the grid in summer, the NSW premier says.

NSW is still the most resilient state when it comes to resourcing energy, Premier Gladys Berejiklian insisted during a budget estimates hearing on Thursday.

Suggesting SA's move to renewable energies was partly to blame for the massive state-wide blackouts, Ms Berejiklian called on the federal and state governments to unite to tackle energy issues.

But she faced a volley of questions from opposition energy spokesman Adam Searle about the closure of the Lidell coal-fired power station in the Hunter Valley.

It's disappearance will reduce the state's baseload power generation by 1000MW.

The federal government confirmed on Thursday it wasn't in any negotiation to buy the ageing plant, which owner AGL wants to close in 2022, but federal Treasurer Scott Morrison says it should remain open.

Ms Berejiklian said she was open to exploring different replacement energy sources but warned against a rapid move away from reliable, established options.