Labor renewables plan a diversion: Hunt

Environment Minister Greg Hunt has accused Labor of an "extraordinary diversion" in revealing details of an ambitious renewable energy target.

Opposition Leader Bill Shorten confirmed his party was proposing a 50 per cent renewables goal by 2030, to be officially unveiled at the ALP national conference later this week.

But Mr Hunt says the move is a ploy to distract attention from a leaked document showing Labor was considering bringing back a carbon tax.

Labor has categorically ruled out a fixed price on carbon, saying its policy is to develop an emissions trading scheme - or floating pollution price.

"This all feels like a massive diversion from a massive leak with massive electricity prices," Mr Hunt told ABC radio on Wednesday.

The parliament recently agreed to slash the bipartisan renewable energy target of 20 per cent from 41,000 gigawatt hours to 33,000 after months of political stalemate that crippled the sector.

Critics are still concerned that target won't encourage enough investment because it only stretches out over the next five years, and investments in big clean energy projects run for up to 20.

Mr Shorten said Labor's plan would create less pollution, more jobs and downward pressure on electricity prices.

He believes there will be a clear choice between his party and Prime Minister Tony Abbott, who he accused of being stuck in the past with dirty energy.

"We think climate change is real," Mr Shorten told reporters in Launceston on Wednesday.

"We understand that Australians expect action."

But he insisted the coal industry remained an important part of Australia's energy mix.

The solar industry predicts the move could create 20,000 to 30,000 jobs.

Australian Solar Council chief executive John Grimes said it represented the "biggest business opportunity probably in Australia's history".

"This is a game changer for Australia's economy," he told AAP.

Labor environment spokesman Mark Butler said Australia had to do its fair share to keep global warming below an increase of two degrees.

ACTU president Ged Kearney conceded jobs would be lost as the economy moved away from coal and towards newer technology.

Mr Butler did not rule out higher power prices under the plan.

But he told Sky News advice received by the opposition shows expanding the renewable energy sector will put downward pressure on prices.

The Clean Energy Council - the industry's peak body - says a longer-term renewables target would underpin billions of dollars in investment.

The Australian Greens believe the 50 per cent pledge is better than the Abbott government's "ideological opposition to clean energy" but still short of what's necessary to limit global warming.

"We look forward to an election campaign in which global warming is front and centre," Greens senator Larissa Waters said.

The Minerals Council of Australia says Labor's target would be economically costly, punish households and hurt Australia's competitiveness.

"Renewable energy must win increased market share on its own merits, not be guaranteed it by massive subsidies," chief executive Brendan Pearson said in a statement.

If claims were correct that renewable energy would soon be cheaper than other sources, there was no need for policy interventions, he said.