Businesses committed to buying renewable energy, and those with no intention of doing so, all believe their decision will save them money.

That conundrum is one of the standout findings in a survey of leading Australian companies and their approach to renewable energy by the Australian Renewable Energy Agency (ARENA).

ARENA, a federal government authority, talked to about 96 of Australia's largest public and private companies and found just under half of them (46) were actively using renewable energy.

Of the other 50 businesses, just nine said they had any interest in looking into renewable energy and named cost as the No.1 impediment.