Renewable power from the Sun, wind, water and biomass can and should generate a major portion of the planet's energy supply by 2050, a leaked draft of a United Nations report says.

Renewables have the potential to bring power to the world's poorest regions, boost energy security for nations dependent on imports, and curb the CO2 emissions that fuel global warming, the draft said.

The 30-page "summary for policy makers" -- boiled down from 1,500 pages -- is being vetted at a May 5-13 meeting of the 194-nation Intergovernmental Panel for Climate Change (IPCC) in Abu Dhabi, and will be unveiled on Monday.

"The final version is likely be substantially different in wording and perhaps somewhat in emphasis, but not a great deal in substance," said an industry representative participating in talks.

By far the most comprehensive UN assessment of the status and potential for the clean energy sector, the report weighs 164 separate development scenarios.