Australia's biggest power grid would need to triple in size within eight years and trillions of dollars would need to be spent, according to a report outlining the colossal task of achieving carbon neutrality by 2050.
But a group of top research institutions, including the universities of Melbourne, Queensland and Princeton from the United States, have found the amount of gas-fired generation capacity will need to double in order to keep the lights on.
Through a partnership known as the Net Zero Project, the universities and consultancy Nous Group will today release the results of a wide-ranging study that aims to paint a picture of a decarbonised Australian economy.
As a starting point, the report found the capacity of Australia's biggest power system — the national electricity market spanning the Eastern States — would have to triple in size by 2030 to keep up with the country's net zero goals.
The authors found that on top of the need for capacity to replace retiring coal-fired generation, it would be necessary to match a massive increase in demand as more of the economy was powered by renewable energy rather than fossil fuels.
Scale 'hard to conceptualise'
To this end, the authors said there would have to be a "rapid rollout" of renewable energy, transmission lines, storage facilities such as batteries, electric vehicles and heat pumps at homes and businesses.
Michael Brear, a director at the Melbourne Energy Institute at the University of Melbourne and one of the report's authors, said the scale of the job ahead defied easy comprehension.
Ultimately, Professor Brear said trillions of dollars would have to be spent in Australia to upgrade and expand the grid and replace lucrative fossil fuel export industries such as coal and gas with clean substitutes such as green hydrogen.
Last year, Australia's exports of coal and liquefied natural gas were worth more than $200 billion.
"We are really just trying to paint a picture of what net zero actually means on the ground for all Australians," Professor Brear said.
"We're not taking a position on which route to getting there is better or worse or more or less plausible.
"But all of them are immense in scale, very complicated and will have significant costs."
According to Professor Brear, gas-fired electricity would play a limited but critical role in keeping the power system stable and the transition to renewable energy at a lower cost.
He said while green sources such as wind and solar power backed by batteries and pumped hydro storage would provide the bulk of Australia's energy needs by the end of the decade, there would be instances when this was not enough.
Gas capacity up, output down
In such circumstances, he said gas-fired power plants would provide crucial "firming" services to ensure supply could meet demand at peak times.
"Our results show that we need more gas turbines but we operate them much less frequently than we do today," he said.
"There are periods across the year when there's not enough wind and not enough sun and not enough storage to do the task.
"So, the gas-fired generation kicks in at those periods.
"The total amount of energy generated from natural gas generation falls considerably, but the assets that provide that power are called on at times to provide very considerable power.
"The greenhouse gas emissions associated with that natural gas generation falls considerably."
Tim Buckley, a leading renewable energy advocate and director at Clean Energy Finance, said the report's findings were credible.
Mr Buckley agreed gas would continue to be used as a fuel to generate electricity at times of peak demand, which typically occurred during extreme weather in summer and winter.
"We will see a progressive shift from gas base-load power generation to gas peakers," Mr Buckley said.
"Increased capacity does not equate to increased generation because what they're really stressing is we need to have grid reliability.
"Batteries will increasingly deliver the short to medium-term duration storage.
"But gas peakers provide a degree of reliable, predictable firming capacity."
Clean exports 'greatest opportunity'
Longer-term, Mr Buckley said the switch to electric vehicles would help stabilise Australia's power system by providing what amounted to a giant battery spread out across the country.
In the meantime, he said Australia's tough electricity reliability standards would underpin the need for gas-fired electricity to provide a safety net for supplies.
Despite this, he suggested that emissions from Australia's gas-fired power players would plummet and that pollution from proposed new gas developments would dwarf anything caused by peaking plants.
"Let's face it, at the end of the day most gas peakers in Australia run 1 or 2 per cent of the time," he said.
"One or two per cent of the time means that the emissions in aggregate are very minor."
Professor Brear said it was imperative that Australia capitalised on the export opportunities presented by decarbonisation given that demand for the country's fossil fuels would inevitably fall away.
Doing so, he said, could support Australia's prosperity for generations.
"Arguably, our greatest contribution to the global decarbonisation task — because decarbonisation only really has meaning in a global sense — is to clean our exports as well as clean our domestic energy system," Professor Brear said.
"It's an immense task.
"But the world is a big place and there's a lot of money outside Australia, and there's a lot of expertise outside Australia to help us do these things."
