Australia's biggest polluters are still nowhere to be seen at auctions for the federal government's direct action money.
The third auction for the $2.55 billion emissions reduction fund purchased $516 million in carbon reduction projects at the lowest price so far.
Results released on Thursday show the main contract was handed to Terra Carbon, which will slash 15 million tonnes of CO2 pollution using land and forestry management.
However, energy market analysts RepuTex says that project likely pushed down the average price, while other contracts were probably awarded at well above the average of $10.23 per tonne.
While the fund had been successful in purchasing a large volume of carbon credits, it had not curbed Australia's emissions growth, RepuTex executive director Hugh Grossman said.
"(Emissions) growth is driven by Australia's largest emitting companies, which have to date not participated in the ERF due to the voluntary nature of the scheme," he said on Thursday.
RepuTex has released modelling that shows Australia's emissions will grow past 2030, despite the government claiming it will meet its five per cent emissions reduction target by 2020.
The latest auction means almost 70 per cent of the government's pool for carbon abatement is gone, with no additional funding allocated in the federal budget.
A review of the policy - which is administered by the Clean Energy Regulator - isn't scheduled until late 2017.
Clean Energy Regulator chair Chloe Munro said she wasn't worried about running out of funding.
"At this stage, we're certainly not concerned about the point at which we would not be able to commit further funds," she told a Senate committee on Thursday.
"What this auction has shown is we can access very competitively priced abatement."
But RepuTex predicts there will only be enough money for one more complete auction this year and the risk of a demand gap continues to loom over anyone trying to develop of project.
It also expects the low price paid in the third auction is the floor and predicts a rebound of cost at the fourth auction.
In total the government has spent $1.7 billion on 309 projects to deliver 143 million tonnes of abatement.
Most of the projects have focused on farming and vegetation practices, carbon capture in waste, regeneration of land and Savanna burning.
The latest auction awarded some contracts for energy efficiency measures.
The average price over the three auctions is $12.10 per tonne, with the final auction bringing that down slightly.
The Climate Institute said the depletion to 30 per cent showed the policy could only ever play a supporting role to a broader climate change plan.
So far just three per cent of the emissions reduction needed to meet Australia's international obligations had been contracted, chief executive John Connor said.
"In fact, it achieves only seven per cent of the reductions needed to meet the government's current inadequate 2030 target."
The government claims Labor's carbon tax cost $1300 per tonne to reduce emissions, arguing its policy is much cheaper.
However institute modelling using the same logic has found under direct action, Australians are paying to increase emissions at about $90 per tonne.
