When it comes to Australian tax-payer funded investment in renewable energy, a Charles Sturt University (CSU) sustainability expert believes there should be more focus on solar-thermal technology.

Adjunct research fellow at the Institute for Land Water and Society (ILWS), Mr Barney Foran's research is examining how to transition to a low carbon economy with economic productivity and energy security.

Mr Foran doesn't agree with the policy of abolishing the Clean Energy Finance Corporation (CEFC) but said the Prime Minister Tony Abbott's move to stop it funding wind farms and roof top solar projects has some merit.

"The Corporation's portfolio is two thirds renewables and one third energy efficiency. Currently, the renewable part is largely split between wind farms at 24 per cent, solar photovoltaic at 22 per cent, and bioenergy at 10 per cent.

"These are relatively mature technologies and the obvious game changer for Australian sun rich areas is solar thermal which has less than three percent of the Corporation's total investment."

Mr Foran argues that solar thermal is the kind of technology the CEFC should be investing in to drive innovation.

"We have to get some decent solar thermal plants up and running," he said. "They don't come in factory made units like wind turbines and PV panels, and as a result they are harder to get the private funding case over the line.

"Solar thermal plants have the advantage of night time power generation because they can store the daytime heat in molten graphite, molten salt or hot oil.

"Getting several of these across the line and developing mature construction and manufacturing chains could underpin the real renewables transition as they can balance, along with gas turbines, the intermittency challenges of single technology investments.

"So while Mr Abbott's intent is a bit hard on wind and solar, in a sense he is right, we should be thinking big about big solar thermal."

Mr Foran said the debate about whether government money should be invested in renewable energy needs to be viewed in a broader context.

"The International Monetary Fund (IMF) estimates Australia's post-tax subsidies for fossil fuel are US$30 billion annually," he said.

"So the debate about how the Clean Energy Finance Corporation's $10 billion portfolio is invested should also be seen against this much higher yearly subsidy to fossil fuels.

"I also note that every dollar currently spent by the Corporation leverages two dollars of private investment funds".