CANBERRA, June 15 (Xinhua) -- The Australian industry will be put at risk unless the federal government's new energy policy guarantees round-the-clock power at internationally competitive prices, according to the country's biggest aluminium producer.

Tomago chief executive Matt Howell said renewable forms of energy were unable to deliver reliable and affordable power to energy-intensive users.

"We cannot, in our approach to this transition, lose sight of the fact that there are 24/7 baseload energy customers," Howell told The Australian newspaper on Friday.

"And we have to make sure our grid can still provide energy to those customers at competitive prices, irrespective of the weather."

His company, based in the Hunter region of New South Wales, produces 593,000 tonnes of aluminium a year, but a sharp fall in available energy last week caused three potlines at its plant to shut down.

Maintenance work meant coal-fired generation was unavailable and this had coincided with low solar generation and higher-than-usual domestic demand.

Howell said Australia's overall baseload capacity had been cut, with coal generation replaced by unreliable energy sources that could not be economically bolstered with gas or battery storage.

Battery storage was not viable for big energy users, noting that South Australia's vaunted solar Tesla battery "would power us for about eight minutes."

"So, our question is: in the absence of wind and solar and commercial reliable storage for energy-intensive industries, where does the energy come from for industries such as ours that need it every minute of the day? Where does it come from when the intermittent generators are simply not providing?"

The so-called national energy guarantee (NEG) is Prime Minister Malcolm Turnbull's signature energy policy, but there are concerns even within his own conservative coalition government that the plan will spell the end for coal-fired power.

Matt Canavan, the government's resources minister and a supporter of coal-fired power plants, said coal remained the cheapest, most affordable option for baseload power.

"What we need is an approach that treats all energy sources equally, and then what the market will then deliver is the cheapest power to meet those reliability needs," Senator Canavan said on Thursday.

In a related development, the Energy Minister Josh Frydenberg has told energy retailers they will see "more intervention" from the federal government if they don't sort out their prices and reliability.

Frydenberg issued the blunt warning to the sector on Friday morning after the release of a new report from the Australian Energy Market Commission showed public trust in retailers had hit record lows.

"My message to the retailers is unless they get prices down and they pick up their act, you will see more intervention because that is what the public will demand of their political leaders," the minister told the Australian Broadcasting Corporation (ABC).

Frydenberg also lashed the publicly listed company, AGL Energy, for the "very poor" decisions it had made in recent times.

AGL, which owns the Liddell coal-fired power station in NSW, was reported on Friday to be moving to import gas into Australia in 2020 - having signed a major export deal more than two years ago which has pushed domestic gas prices higher.

"What AGL did was a very, very poor decision," Frydenberg told Sky News. "They have a lot of explaining to do to their customers because their customers are paying more for their gas than they should have been had AGL decided not to export that amount of gas."