Building a large-scale nuclear power plant in Australia would cost at least A$8.5 billion and take 15 years to complete, producing electricity at roughly twice the cost of renewable sources, according to a report from the CSIRO.
The GenCost report found nuclear energy's costs were similar to gas- and coal-fired generation with carbon capture and storage but still about 50% more expensive than large-scale wind and solar power supported by battery technologies.
Chief economist of the CSIRO's energy business unit Paul Graham said, "We did a lot of work to determine what nuclear power would cost in Australia ... That's still one and a half to two times the cost of renewables."
The report highlighted significant risks associated with nuclear power, citing potential cost and time overruns, especially as Australia has no experience with nuclear plant construction. It suggested that cost premiums of up to 100% could not be ruled out for a 'first of a kind' plant.
Shadow Energy Minister Ted O'Brien did not contest the capital cost estimate but disagreed with the conclusion that nuclear energy would be twice as costly as renewables. He said the Coalition's modelling details would be released in due course.
Slow, expensive and risky
Politically, the debate over nuclear energy in Australia continues, with the federal Coalition viewing it as a potential solution for decarbonisation. Opposition Leader Peter Dutton has suggested building large-scale nuclear reactors on sites of retiring coal-fired plants.
However, Energy Minister Chris Bowen reiterated that renewables remained the cheapest energy source, describing nuclear as "slow, expensive and risky."
The CSIRO noted the challenges of establishing nuclear energy, including legal, safety and security hurdles, and longer construction times compared to other technologies.
“The first issue is the legal hurdle ... The second is they've got extra safety and security steps ... And finally, they have the longest construction time of any technology," said Graham.
In contrast, the report confirmed that onshore wind and solar are the most cost-effective new electricity sources, even when factoring in the costs of supporting technologies like batteries and pumped hydro plants. The average cost of new renewable projects was A$119/MWh in 2023, expected to drop to A$99/MWh by 2030.