Tasmania stands to be a big loser as the Federal Government pursues its "clean coal fantasy", according to Greens senator Nick McKim.

The Federal Government has not ruled out using the Clean Energy Finance Corporation to fund a new generation of coal-fired power stations.

It comes as a feasibility study on a second undersea power cable between Tasmania and Victoria is due out any day.

Senator McKim said there was no such thing as "clean coal", and the move would affect renewable energy investment in Tasmania.

"The Clean Energy Finance Corporation has a finite pool of funds, so any dollar that goes into so-called clean coal is a dollar that won't go into renewable energy," he said.

"And renewable energy is one of Tasmania's biggest competitive advantages.

"The risk is that Tasmania is going to miss out on really exciting renewable energy projects because Malcolm Turnbull wants to throw money designed for renewable energy and allocated to renewable energy into a fantasy of clean coal."

Senator McKim said moving back to coal would impact on investor confidence in renewable energy.

"That will shake confidence in investment around the country, including here in Tasmania," he said.

Tasmanian Energy Minister Matthew Groom said his government would continue to promote renewable energy in the state.

"I understand why it is the Federal Government want to have a broad conversation about energy," he said.

"There's no doubt at all there are significant challenges the national market is confronting when it comes to the transition to cleaner energy.

"The Tasmanian Government is committed to maximising the advantages we've got as a state in renewable energy — that's our focus."