If long-term greenhouse gas emissions in Australia are to be reduced, renewable energy is likely to be critical. This is particularly so if deep cuts are eventually implemented. Current government policies ( including emissions trading and electricity, the feed-in tariffs announced in 2008), are likely to have only modest impacts on renewable electricity generation in Australia at least until 2020. Australia’s renewable electricity base will remain narrow with little solar technologies’ contribution before 2020. This will not provide an adequate basis for delivering long-term deep cuts to Australia’s greenhouse emissions nor for achieving major greenhouse gas emission reductions at least cost. The future of Australia’s renewable electricity rests mainly with the success, or otherwise, of its Mandatory Renewable Energy Target and expanded Renewable Energy Target. Their effectiveness may be eroded, however, by the long-term banking of tradable certificates used with both target mechanisms. Unless there is a change of policy mechanisms, Australia will probably fail to reach its renewable electricity target of 20 per cent by 2020. Australia will also fail to build up its solar and hot rock geothermal electricity generation capacity to make large supply contributions beyond 2020.