Mr Corbell  held an ACT Legislative Assembly seat for nearly 20 years, making him  the territory's longest-serving politician, and held some of the toughest portfolios, including attorney-general's, police and emergency services, health and environment and climate changes.

Mr Corbell is also a Labor-left factional stablemate of Victorian Environment Minister Lily D'Ambrosio, who will announce the appointment on Friday.

But the former ACT politician is steeped in clean energy policy and politics after years in charge of planning and executing a succession of of ambitious schemes for wind and solar power to fuel the national capital.

As ACT environment minister, Mr Corbell was the driving force in the territory's push towards clean power, pursuing programs to deliver 100 per cent renewable energy for Canberra by 2020 generated by of 11 large-scale wind and solar projects in the ACT, NSW, Victoria and South Australia.

Among his last acts as minister was the purchase of a fleet of hydrogen cars for the government and putting some of its public servants on electric bikes.

He was also the man given the political tricky job of selling Canberra's biggest ever public transport project, the $1 billion Capital Metro light rail build, in the face of a determined campaign against the plan by the Canberra Liberals opposition.

Mr Corbell declined to talk to Fairfax for this article but drawing the curtain on his political career in August after failing to secure preselection for October's territory election, he set his sights on a new career in renewables saying he would "certainly grasp it and seize" any opportunity in the sector.

"For me, the pursuit of renewable energy, of climate change and sustainability, is not an end of itself," Mr Corbell said.

"It's an end towards a more just and equitable society ... that we can enjoy, and future generations can enjoy."

The advocate's position is new and is understood to be part of the Andrews' government's broader renewable energy strategy which is also yet to be fully announced.

Victoria's ambition is to have 25 per cent of the state's energy from renewable sources by 2020 and 40 per cent by 2025.

Ms D'Ambrosio's office said in a statement that the Andrews government was looking forward to making an announcement soon.