Renewable generation in Australia has almost doubled since 2001, and investment in large-scale and small scale renewable energy projects exceeded 5 billion (almost 5. 26 billion U.S. dollars) in 2011, a latest report from the Climate Change Authority shows on Wednesday. The Authority, established on 1 July 2012, provides independent advice on the operation of Australia\'s carbon price, emissions reduction targets, caps and trajectories, and other Australian government climate change initiatives. As the figures show, renewable electricity generation accounts for more than 10 percent of Australia\'s total generation. Under the current the Renewable Energy Target (RET) scheme renewable electricity generation is forecast to grow from around 30,000 gigawatt hours (GWh) at present to around 65,000 GWh in 2020-21, and reduce greenhouse gas emissions by around 102 million tones over the same period. The report said it believed the scheme, which aims to ensure 20 percent of Australia\'s electricity comes from renewable sources by 2020, is progressing towards its objectives and reducing greenhouse gas emissions in the electricity sector. It also outlined its key recommendation that the large-scale Renewable Energy Target for 2020 remains unchanged at 41,000 GWh, as currently legislated and the scheme be reduced in frequency from the current two-yearly intervals to four-year intervals to help provide stability for investors. \"Stop-start changes to the renewable target have undermined investor confidence and stymied investment in clean energy,\" said Erwin Jackson, deputy CEO of the Climate Institute. \"To deliver lower cost and affordable clean energy investors in renewables need stability and predictability from policymakers.\" But Adam Bandt, acting leader of the Australian Greens, said Australia needs further stronger target in a statement. \"Given its mandate to put forward policies to address catastrophic global warming, the Authority should have pushed for a stronger renewable energy target.\" Bandt said. \"The Authority needs to take this mandate seriously when it advises on further targets for the price on pollution, otherwise it risks being left behind by the reality of climate change.\" Climate Change Minister Greg Combet later Wednesday said the government would respond to the recommendations early in 2013. He said Labor recognized the importance of stability of the nation\'s climate change policies.