The International Energy Agency (IEA) published its Medium-Term Renewable Energy Market Report yesterday.
The report shows that global investment in renewable energy technologies has fallen year on year since 2011 when it peaked at almost $280m.
In 2013 the IEA says that figure was $250m and it predicts that this will continue to decline for the rest of the decade.
The IEA reasoned that this could partly be attributed to the reducing cost of proven renewable technologies however it also warned that uncertainty over energy policy, particularly in OECD countries, is hampering investment.
The organisation said that established renewables markets face significant challenges in coming years to balance the need to reduce incentives while continuing to ensure reasonable returns for investors.
Despite the declining investment rate however, IEA expects global renewable electricity generation to grow by 45 per cent by 2020 at which point it will account for 26 per cent of global electricity generation.
Investment in OECD nations is predicted to account for 30 per cent of this growth and IEA says 55 per cent of growth in non-OECD nations will be driven by China.