Peter Dutton’s plan to build less renewable energy and keep Australia’s coal plants running longer has overestimated the reliability of ageing generators and could lead to major electricity shortages, according to a new analysis.
The Coalition has pledged to put taxpayer-funded nuclear reactors at seven sites around Australia and has pointed to modelling by Frontier Economics that shows the country’s ageing coal fleet would need to take up the slack in electricity generation while they are built.
But the Institute for Energy Economics and Financial Analysis (IEEFA) said the modelling had assumed the ageing coal plants would be able to generate between 72% and 81% of their capacity, much higher than previous plants that were near the end of their life.
The IEEFA report looked at the 13 coal plants to have closed since 2000 and found in the 10 years before they were turned off, they were only available on average 66% of the time due to unplanned outages and the need for increased maintenance.
When IEEFA adjusted the Coalition’s numbers between 2034 and 2043 to account for what it said was a more realistic estimate of the coal fleet’s capabilities, it found a shortfall of 9,300 gigawatt-hours a year – the equivalent of the power consumed by 2 million households.
Johanna Bowyer, lead analyst on Australian electricity at IEEFA, said failing to account for the poor performance of an ageing coal fleet would risk unexpected coal outages “and a system that hasn’t been built to account for them”.
Tristan Edis, a co-author of the report and analyst at Green Energy Markets, said the average age of a coal plant when it retired was 42 years.
“Over the 2030s, the existing coal-fired power stations will be close to, or have exceeded, the age at which past coal plants typically retired.
“We should be planning for the likelihood that they will suffer a similar deterioration in their availability.”
A report commissioned by the Climate Council last year looked at data from 2014 to 2024 and found coal plants less than 40 years old were available for 81% of the time, dropping to 65% in their later years.
Edis said if a future government was forced to rely on more gas generation to fill the gaps, this would burn between 49 and 93 petajoules of gas annually from 2034 to 2043.
Edis said: “This is a large amount of additional gas considering the average amount of gas used for electricity generation over the past five years was 122PJ per year.
“This additional gas requirement would have serious consequences for the price and availability of gas for other consumers.”
Danger of nuclear delays
The modelling backed by the Coalition assumed the first nuclear reactor would be producing power by 2036, with further plants coming online from 2039 onwards.
Many energy experts, including the CSIRO, have been less optimistic, saying it could take until the early 2040s before a plant could be operating, and possibly longer.
The IEEFA report said four nuclear plants recently brought online in Europe and the United States had seen delays of between six and 14 years – an average delay of 11 years.
Bowyer said: “If we have an 11-year delay with the nuclear build, we would see a huge energy supply gap. Filling that gap with new generation becomes really tricky and extending those coal plants even further just exacerbates the risk [of them becoming less reliable].”
Guardian Australia approached Frontier Economics for comment.
A statement from the Coalition said Labor’s renewables-based approach was “forcing the premature closure of coal generation – well before their notified closure dates”.
“Proper maintenance can ensure coal plants are not closed prematurely. The Coalition’s approach, based on comprehensive and evidence-backed modelling, ensures that coal continues to play a crucial role in Australia’s energy mix, both now and in the future.”
The Frontier modelling was a “realistic and comprehensive view”, the statement said, of the maintenance costs for coal plants “while recognising the ongoing importance of coal in maintaining grid stability during the energy transition”.
“Labor talks about phasing out coal, but behind closed doors they are cutting deals with the states to keeping them online.”
