Massive introduction of solar-thermal power plants and wind farms would allow Australia to generate all its energy needs from renewable technologies by 2020, research shows.

The report, to be announced today by the retiring Liberal Victorian senator Judith Troeth, the Greens senator Christine Milne and the Independent Nick Xenophon, finds a 100 per cent renewable plan by 2020 would cost $37 billion a year, in public and private money - or 3 per cent of Gross Domestic Product.

The report is the result of research collaboration between an environment group, Beyond Zero Emissions, and Melbourne University 's Energy Research Institute, with input from engineering firm Sinclair Knight Merz.