Investment in renewable energy last year amounted to a record 211 billion dollars, a rise of 32 percent over 2009 and 540 percent over 2004, a UN-backed report said on Thursday.

China, investing 48.9 billion dollars, up 28 percent, accounted for more than a fifth of the total, marking a year in which developing countries for the first time outstripped rich economies in renewables investment, it said.

A combination of factors were behind the global surge, said the report.

They included stimulus money earmarked after the 2008 financial crash that was now finding its way into the market, sustained prices for fossil fuels, and government perks such as feed-in tariffs for cleaner power.

The report, Global Trends in Renewable Energy Investment 2011, is a collaboration of the UN Environment Programme (UNEP), the Frankfurt School of Finance and Management in Germany and Bloomberg New Energy Finance.

If large hydro dams are excluded, renewable power comprised 8.1 percent of total world power generation capacity in 2010, compared with 7.1 percent in 2009, said the report.

Despite this small share of the mix, renewables accounted for 34 percent of additional capacity brought online last year.

The report made these points:

-- The most mature technology, wind, continued to dominate the renewables sector, accounting for 94.7 billion dollars of investment projects in 2010. Solar investment was 26.1 billion and biomass and waste-to-energy projects amounted to 11 billion.

-- But solar very nearly catches up with wind if small-scale installations, such as rooftop photovoltaic (PV) panels, are included.

Small-scale solar sector doubled in value last year, helped by feed-in subsidies especially in Germany, France, Italy and the Czech Republic.

These subsidies are now being pared back by governments, but even so the market "is likely to stay strong" in 2011, says the report.

-- The cost-effectiveness of wind and solar has risen enormously. The price of PV panels per megawatt (MW) has fallen by 60 percent since mid-2008, and that of wind turbines by 18 percent.

"Further improvements in the levelised cost... lie ahead, posing a bigger and bigger threat to the dominance of fossil-fuel generation sources in the next few years," says the report.

"The tipping point where renewables becomes the predominant energy option now appears closer than it did just a few years back."

-- Investment growth in the Middle East and Africa was up 104 percent to five billion dollars, while India saw a rise of 25 percent to 3.8 billion dollars.

In Asian countries outside India and China, there was a rise of 31 percent in investment to four billion. South and Central America, meanwhile, had an increase of 39 percent, to 13.1 billion.

-- Government research and development rose by 120 percent to more than five billion. But corporate R&D fell by 12 percent.

The report counted all biomass, geothermal and wind generation projects of more than one MW, all hydro projects of between 0.5 and 50 MW, all solar projects of more than 0.3 MW, all marine energy projects and all biofuel projects with a capacity of one million litres or more per year.

It did not not include "energy-smart" technologies such as smart grid, electrical vehicles and power storage.

By early 2011, the report added, 119 countries around the world had policies or targets in place to support renewables, more than half of them in the developing world.