SA nuclear energy impractical: Diesendorf

Most of Australia could be powered completely by renewable energy by 2030, making nuclear redundant, an environmental policy expert has told a nuclear energy royal commission in Adelaide.

"We found that we could run the whole Australian national electricity market, including South Australia, on renewable energy using commercial technologies scaled up," UNSW Institute of Environmental Studies deputy director Dr Mark Diesendorf told AAP on Monday.

But he said the study this is based on did not include Western Australia or the Northern Territory, as they weren't on the national electricity grid.

Dr Diesendorf, who was commissioned by the Conservation Council SA to investigate whether the state could rely completely on renewables by 2030, said solar and wind energies were cheaper and more viable than nuclear.

"It would take 15 years to build the first nuclear power station and by that time we could have 75 per cent solar power in South Australia," he said.

"The technologies that are being proposed for nuclear at the royal commission don't exist commercially yet. They only exist as pilot plans and designs."