Can a country run entirely on renewable energy?
Businessman Dick Smith has thrown his support behind calls to introduce nuclear-generated power to Australia, rejecting renewable-led electricity generation in the process.
Appearing on Sydney radio station 2GB earlier this week, Mr Smith said Australia "should be making a decision to go nuclear now", pouring cold water on suggestions that wind and solar — and renewables more generally — could instead lead the nation's energy transition.
"Look, I can tell you, this claim by the CSIRO that you can run a whole country on solar and wind is simply a lie," Mr Smith said.
"It is not true. They are telling lies. No country has ever been able to run entirely on renewables — that's impossible."
But experts consulted by RMIT ABC Fact Check suggested Mr Smith's statement doesn't hold up.
Mark Diesendorf, an expert on sustainable energy and energy policy from the University of New South Wales, labelled Mr Smith's assertions as "incorrect".
"Several countries (and Tasmania) already run their electricity systems on 100 per cent renewables," he said in an email, noting that such places relied heavily on hydro power.
Even when focusing on wind and solar-generated power alone, experts rejected Mr Smith's claim that it would be "impossible" for it to power an entire country.
Andrew Blakers, a professor of engineering at the Australian National University's Institute for Climate, Energy and Disaster solutions, told Fact Check:
"Several detailed studies show that [getting to] 100 per cent renewables based mostly on solar and wind is quite straightforward, provided that enough transmission and storage is built."
Professor Blakers pointed to studies conducted by his research group investigating the feasibility of 100 per cent renewables in a number of countries, including Australia.
"[Solar] and wind [would] allow Australia to reach 100 per cent renewable electricity rapidly at low cost," concluded one such study, co-authored by Professor Blakers and published in 2017.
As for the countries putting renewable power to the test, Mark Z. Jacobson, a professor of civil and environmental engineering at Stanford University in the US, and director of its Atmosphere/Energy Program, pointed Fact Check to a detailed list of countries at or near the 100 per cent renewable energy mark.
"There are four countries running on 100 per cent wind-water-solar (WWS) alone for their grid electricity," he said in an email, noting that a further three countries relied on WWS for 99.78 per cent to 99.99 per cent of their electricity generation, while 45 countries were above 50 per cent.
According to a document produced and supplied by Professor Jacobson, the four countries running on 100 per cent WWS in 2021 were Albania, Bhutan, Nepal and Paraguay.
When it came to regions with a comparable or greater population size to that of Australia, Professor Jacobson pointed to the US state of California, which has a population of around 39 million.
As of Tuesday this week, he said, the state, which is aiming for 100 per cent carbon-free electricity by 2045, had "been running on more than 100 per cent WWS for 10 out of the last 11 days for between 0.25 and 6 hours per day".
While it is not entirely clear what Mr Smith was referring to when he suggested the CSIRO had claimed Australia could run entirely on wind and solar, the national science agency's latest annual GenCost report, released in July 2023, found that wind and solar remained the cheapest form of new-build electricity generation.
An updated draft of the report, released last month after factoring in feedback related to integration costs prior to 2030, also found renewables to be the cheapest form of new-build energy.
The Australian Energy Market Operator (AEMO) has forecast that renewables will be able to meet the entire demand of the national electricity market (NEM) by 2025, albeit for short periods of time (for example, 30 minutes).
Introducing AEMO's 2022 Engineering Roadmap to 100 per cent Renewables, CEO Daniel Westermen wrote that "the power system will require additional engineering solutions to provide essential system services to maintain a stable electrical voltage and frequency and ensure a secure state of operation".
"Proven technologies such as synchronous condensers will play a role, alongside newer technologies such as grid-forming inverters. The human dimensions of this transition are as important as the technical requirements."
In addition, a 2021 report from the Grattan Institute noted that "getting to 100 per cent renewable energy [in Australia] over the next two decades would be expensive unless there are major technological advances to backup renewable supply through rare winter wind droughts".
"That's why Australia should commit only to net zero emissions in the NEM by the 2040s, not absolute zero emissions or 100 per cent renewable energy."
As the institute's James Ha explained at the time, net zero emissions doesn't "require that all electricity people use within the jurisdiction come from renewable sources".
"Some might come from coal or gas-fired generation, but the government offsets this amount by making or buying an equivalent amount of renewable electricity."
