The reliability of "high efficiency low-emissions" (HELE) coal fired power plants is being questioned, with a new report finding they break down more often per gigawatt than older generators.
Australia's newest coal power station, the 12-year-old Kogan Creek plant in Queensland, broke down six times last year, the Australia Institute found.
"It's already broken down this summer during a heatwave," the Australia Institute's Richie Merzian said.
"These new supercritical coal plants are touted by proponents as 'high efficiency, low emissions' coal plants, but this could not be further from the truth.
"Our research shows that not only are these HELE coal plants just as unreliable, but they are more emissions intensive than renewable energy and even gas."
HELE coal plants operate above a "critical" temperature and pressure level, which in theory makes them more efficient and emit lower emissions than other coal plants.
The Australia Institute has been tracking coal-fired power station breakdowns since 2017.
Black coal power plants in the National Energy Market broke down 74 times last year, about one every five days.
The newer HELE plants accounted for 13 of these breakdowns, with the plants making up six per cent of the NEM's capacity.
The Australia Institute found that per gigawatt of capacity, there were 4.4 breakdowns from HELE plants, compared to four at the older black coal plants.
Meanwhile, registrations of interest closed on Wednesday for the government's underwriting new generation investments program, with a shortlist expected in coming weeks.
A spokesman for Energy Minister Angus Taylor told AAP there had been strong interest in the program.
"The government will carefully consider all proposals - some of which have already been reported in the media - and we'll have more to say once we have considered all the submissions and feedback received during this process," the spokesman said.
One such submission that has made headlines is ERM Power founder Trevor St Baker's Chinese-backed $6 billion plan for coal plants in Victoria and NSW, as well as a pumped hydro facility in SA.
Although Labor has said it would honour any contracts in place if they win government, Opposition Leader Bill Shorten said there should be more renewables in the mix.
"We do want to move the Australian economy away from reliance on coal," he told reporters in Queensland on Thursday.
"We want to see more renewables in the energy mix but it is not an either or. Exporting coal is part of Australia's story."
