Australia could be the “energy capital of Asia” but instead it is going backwards, Bill Shorten will say in a speech on Thursday, vigorously defending Labor’s target of 50% of Australia’s electricity coming from renewables by 2030.

As the government floats the prospect of help for cleaner-coal power stations and attacks Labor for committing too strongly to renewables, Shorten will say that to achieve the ALP’s 50% target much more private investment in renewable generation and technology will be needed than the amount required to get to the legislated Renewable Energy Target (RET). The RET is for 23.5% of Australia’s electricity generation in 2020 to come from renewable sources.

He will say that what is required is an emissions-intensity scheme (EIS) for the electricity sector, ongoing support for research and investments in renewable energy technology, and a plan to modernise the National Electricity Market.

The speech comes as an Essential poll this week found nearly two-thirds (65%) approved of Labor’s target of 50%; 18% disapproved. Support for the policy was 55% among Coalition voters.

After much debate last week about the precise nature of Labor’s 50% commitment – whether it was a “goal” or a “target” – Shorten will take a more assertive line. “Forget the word games – 50% renewables by 2030 is Labor’s target, our goal, our objective and our aspiration,” he will say.

“We can be the energy capital of Asia. And if Australia nails the energy question, we will collect a growth dividend that can set us up for the century.

“But despite the prize on offer, despite all our natural advantages, we’re not just stuck in the gates – we are going backwards.

“When the Coalition came to office and declared war on the RET scheme, investment in large-scale renewables fell by 88% in one year.

“After being rated one of the four most attractive destinations in the world for renewable energy investment in 2013, we now don’t even crack the top ten.

“In the last three years, the world has added nearly three million jobs in renewables energy – and Australia has lost 3000,” Shorten will say, speaking at Bloomberg.

Bloomberg has estimated the Labor target would need about $48 billion in new investment. Shorten will say: “That’s not a cost figure. It is money brought into the economy by renewable energy. It is investment in technology, financing, energy generation, advanced manufacturing and installation that will create 28,000 jobs.”

He will say that without confidence in the policy environment, investors would never put up the billions of dollars required for energy projects.

The first and most important step to provide that certainty and to assist the transition to renewable energy is to establish an EIS for the electricity sector, he will say. An EIS rewards energy generators that produce pollution levels lower than a set benchmark.

An EIS would drive investment in new sources of energy – renewables but also gas, Shorten will say.

“An EIS doesn’t rely on taxpayer funding or government officials making investment decisions. It leaves both decisions and funding to the private sector, to the market,” he will say. “It will reduce power bills and reduce pollution.”

Malcolm Turnbull has ruled out an EIS despite the preliminary report of the Finkel inquiry into future security of the national electricity market giving it a positive nod.

Energy Minister Josh Frydenberg on Wednesday met the executive director of the International Energy Agency, Fatih Birol. Frydenberg said carbon capture and storage technology, high-efficiency, low-emission coal-fired power stations, and the improvements in the technology of battery storage were canvassed in their discussion.