Media report (2013): “Switching Australia to 100 per cent renewable power within decades could end up costing the same as continuing to use fossil fuels, a federal government study suggests. Modelling by the Australian Energy Market Operator shows sourcing 100 per cent of power from solar, wind and other clean sources would be technically viable by 2030, albeit with the cost ranging from $219 billion to $252 billion. But a "community summary" quietly published this month has rekindled debate by saying a massive renewable expansion would be no more expensive than expanding conventional energy.” [1; see also [2]].
[1]. Peter Hannam, “Clean energy switch possible by 2030, at fossil fuel prices”, Sydney Morning Herald, 24 August 2014: http://www.smh.com.au/national/clean-energy-switch-possible-by-2030-at-fossil-fuel-prices-20130823-2sgyc.html .
[2]. AEMO Report on 100% renewable electricity scenarios: http://www.climatechange.gov.au/reducing-carbon/aemo-report-100-renewable-electricity-scenarios .