At least 70 sites will need to be built if a major contributor to Australia's clean energy future is scrapped, the Queensland government warns.
Opposition leader David Crisafulli pledged to ditch the controversial Pioneer-Burdekin hydro scheme near Mackay if elected in October, calling it a "multibillion-dollar fantasy".
The scheme is the centrepiece of the state government's renewable energy transition plan, with this week's budget featuring $1 billion in equity and $38.5 million in funding for the proposed project.
The project has caused controversy with concerns it will lead to flooding, displacement of endangered species and cost blowouts.
Liberal National Party leader Mr Crisafulli said, if elected, smaller and more manageable pumped hydro projects would be built instead of the Pioneer-Burdekin scheme.
But a government report on Friday showed at least 70 sites across the state would be needed to match the capacity of the Pioneer-Burdekin power station.
"The publicly-owned Pioneer-Burdekin project will be the single most significant contribution to the nation's clean energy future," Energy Minister Mick de Brenni told parliament on Friday.
If the scores of smaller projects were built around the state by the LNP there would be significant impacts, the report said.
"Those other projects mean higher capital costs, more costs per megawatt hour, more impact on ecosystems, more displacement of households and communities," Mr de Brenni said.
Deputy Premier Cameron Dick said the opposition's proposed smaller projects could lead to 35 times more environmental studies, access roads, transmission lines and reservoirs to be built.
"Those who advocate smaller, more manageable pumped hydro projects are dealing in an unmanageable fantasy," he said.
"What they (LNP) really mean is a plan to squeeze more life out of ageing coal-fired power stations on the way to building nuclear power stations up and down the east coast of Queensland."
The report said 2000 potential sites were assessed when considering a pumped hydro site, with Pioneer-Burdekin coming out on top.
The Pioneer-Burdekin scheme is supported by environmental advocates who say it is the way forward to meeting renewable targets.
"Such long-duration storage is crucial to getting to our 80 per cent renewable energy target and beyond," Queensland Conservation Council director Dave Copeman said.
The government on Friday revealed early works at the Pioneer-Burdekin site had started with drilling to investigate the viability of rock for the construction.
But the opposition remained undeterred.
"We will investigate smaller, more achievable manageable sites and there are many sites," opposition energy spokeswoman Deb Frecklington said.
"There are 16 sites in this (government report) document alone that they've refused to tell Queenslanders why they weren't investigated."
