Mr Kean, who quit state politics on Tuesday, will lead the independent statutory body which advises the Commonwealth on climate change policy.
Often outspoken on climate issues within the NSW Liberal Party, Mr Kean's appointment was announced by the federal Labor government on Monday.
"My role is to bring my expertise and experience to provide independent advice to the government of the day - whoever that should be - based on facts, based on science, based on economics and engineering," he said.
"We have an opportunity to become a stronger and even more prosperous nation, we have an opportunity to deliver families some of the cheapest electricity bills anywhere in the world.
"But we've got to get it right, this is too important to leave to chance."
Prime Minister Anthony Albanese said he's previously worked well with Matt Kean (centre). (Lukas Coch/AAP PHOTOS)
Prime Minister Anthony Albanese said Mr Kean was "uniquely qualified" to lead the body.
"I worked very closely with Mr Kean when we introduced our coal and gas and our energy price relief plan in partnership with the NSW state government and other state governments as well," he told reporters in Canberra.
"Mr Kean understands the opportunity that the transition to clean energy represents for our nation."
Mr Kean, who is also a former NSW energy and environment minister, had previously said he was retiring from politics to join the private sector.
But this opportunity will instead allow him to continue his public service, he said.
Nationals frontbencher Barnaby Joyce accused Mr Kean of treachery for taking on the role.
"Disloyalty is a curse," he said.
"(He's) shown to all the people who supported him, raised money for him, gave him a career, just thrown it back in their faces and said, 'here I vomit on you'."
Matt Kean says nuclear power would take far too long and be far too expensive. (EPA PHOTO)
As the energy debate flares over the opposition's proposal to build seven nuclear plants, Mr Kean referred to his own experience examining nuclear during his time in NSW politics.
"In order to bring nuclear into the system, it would take far too long and be far too expensive for New South Wales," he said.
"I didn't want to bankrupt the state, and I didn't want to put those huge costs onto families.Â
"That's why we introduced the electricity infrastructure roadmap, which planned the transition to renewables backed up by firming storage."
Mr Kean will take over from Grant King, who resigned after more than three years in the role.
10°C