Origin Energy boss Frank Calabria says the era of new coal power is over.

But Mr Calabria says companies are holding off on new investment decisions because they do not know what the government will do to the market.

He says the system needs proper price signals.

“People are sitting around boardroom tables making a decision as to what's their next investment. Now, no one actually gets perfect certainty but think about the decision they're facing,” he told the ABC.

“Participants are very much worried about the fact that the rules could change at any time.

“So there is quite a degree of uncertainty.

“It is very difficult to make an investment that sustains over decades.”

He said a proper pricing signal would encourage companies to build batteries, hydro and gas generators.

He also backed form of emissions intensity scheme.

“I just firmly believe it's the signal that will give confidence to the investment changeout that's under way,” he said.

But he does not support the kind of “capacity payments” used in Britain, which have seen coal plants staying open longer and more diesel generators entering the system.

The Origin head was criticised online by Resources Minister Matt Canavan, who said energy companies “are a big reason why we are in this mess”.