Who's funding the green energy revolution? Financial investment in renewables is greater now than at any time in human history $257 billion was invested in green tech and fuels in 2011 Private sector investment in renewables is nearly double that of the public sector Despite increased investment, renewable technologies still only account 6% of global energy supply Click on the interactive above to see how investment in the renewable energy sector has developed in recent years, the technologies attracting the most funding and the regions and countries making the biggest financial commitment to clean energy. (CNN) -- Money invested in renewable energy reached new heights last year, topping $257 billion. So is the world finally going green? The figures come from The Global Trends in Renewable Energy Investment 2012 report, a UN Environment Program backed study that has tracked the finance flowing into green energy across the world since 2004. It found that renewables accounted for 44% of all new energy generation capacity added last year, up from 34% in 2010 and just 10.3% back in 2004. The source for most of this finance came from the private sector, according to the report. Investment from the private domain in research and development of new technologies was almost double that of governments and public bodies. While Europe attracts most of the investment, the renewable energy sectors of emerging economies such as India and China have been given the biggest boost. China overtook the U.S. in terms of total annual investment in renewable energy in 2009 and attracted more money than any other country ($52.2 bn) in 2011. India meanwhile saw the fastest expansion rate for any large renewables market last year, with a 62% increase in capital funding. But while investment in green energy has been on the rise it still lags far behind traditional fuel sources in terms of contribution to global power supplies. Private financiers aren't going to go into renewables unless there is a commercial benefit Kirsty Hamilton, Chatham House Only 6% of the world's energy requirements (excluding large hydropower, like dams) were generated by renewable sources in 2011. Nor have clean tech companies escaped the volatility of financial markets. The average share price of companies on the WilderHill New Energy Global Innovation Index fell by 40% in 2011, while austerity measures in many developed countries have weakened the policies set up to encourage renewable energy investment. CNN asked two experts in the field about the trends shaping the figures from the report and what it might mean for the future. Dr Karlheinz Knickel is the head of the Frankfurt School for Climate and Sustainable Energy Finance. Kirsty Hamilton meanwhile is an expert at the Renewable Energy Finance Project at UK-based think-tank Chatham House. CNN: What is driving increased investment in renewable energy as displayed in the GTRE report? Karlheinz Knickel: On a global level I guess it's the increasing prices of fossil fuels. This reflects increasing scarcity worldwide which of course provides incentive to look for alternatives. Probably it's also more ambitions of countries to go for clean energy and alternative energy supplies. Of course the third biggest factor is climate policy and the need to reduce carbon dioxide emissions and greenhouse gasses. CNN: How does investments in renewables compare to investment in fossil fuels? KK: It's about half at the moment between fossil fuels and renewable for new technology investment. One important factor however is that there remains substantial subsidies for fossil fuels. Globally we have $400 billion for fossil fuels and I think a comparable figure for renewables is just $66 billion. This shows the massive support provided to fossil fuels irrespective of the technology related questions. CNN: Does the increasing amount of private sector investment in clean tech disprove the notion that renewables can't be profitable? Kirsty Hamilton: Private financiers aren't going to go into renewables unless there is a commercial benefit, particularly now. Countries (like China and India) see opportunities to export technologies worldwide and they are doing that at the lowest prices. Karlheinz Knickel, Frankfurt School At the moment however renewables still need government subsidies. Nevertheless you have to set this question of policy in the context of whether there is a level playing field between conventional energy and renewable energy and even energy efficiency, and that's not the case. CNN: How has the financial crisis impacted public and private investment in renewables? KK: I actually think in terms of a medium or long term trend it doesn't mean too much because these larger factors, scarcity of fossil fuels and the business opportunities, the need to change for climate reasons, all that has a much bigger influence. KH: In the first response to the financial crisis you had government stimulus packages, which created the backdrop of more confidence and renewables was part of an economic growth and jobs story. What's different now is that the economic conditions have become much tighter. This hasn't happened everywhere but austerity has been pinching in on renewable policy and frankly any policy that's had government support behind it. I think it's important to say that financiers are looking for stable policy. There have been some very poorly managed changes to renewables policy adding to the sense in some markets, such as the EU and probably the U.S. as well, that governments are just not confirming their commitment in this direction. CNN: Why do some renewables attract more investment than others? KK: It's hard to generalize. One should be careful interpreting rapid growth in, for example the U.S. this year. One of the background factors is that the relatively supportive (government) renewable programs are being discontinued. I think there was a huge investment in 2011 but there may be quite a traumatic fall in 2012 and 2013. KH: The scale of investment is going to be towards the more mature technologies because there is a longer track record there, and less risk, for example in onshore wind and solar energy. Offshore wind is attracting a lot of interest as a growth sector, but risks go up as it goes further offshore. Essentially, more finance will come in where there are lower technological risks. CNN: Why is investment in renewables seemingly growing faster in developing world countries like India and China? KK: Countries (like China and India) see opportunities to export technologies worldwide and they are doing that at the lowest prices. They really have strong companies and competitiveness with often lower production costs. With their rapid rate of change and demand for energy and good modern services, there is a great risk. But I think I can say for China and India and probably for others that it has been recognized that we are going too much into fossil fuels, accelerating carbon dioxide emissions in a very traumatic way. KH: It's important not to generalize but a couple that one would draw out is that it's been a tougher investment environment in many of the European and U.S. markets in recent years. India and China meanwhile have attracted finance and are creating a strong, positive investment environment so money is able to go to those markets.