"Governments must remove the question marks over renewables if these technologies are to achieve their full potential, and put our energy system on a more secure, sustainable path," IEA Executive Director Fatih Birol said.
Releasing the 'Medium-Term Renewable Energy Market Report 2015' in Istanbul, Birol said, renewables are poised to seize the crucial top spot in global power supply growth, but this is hardly time for complacency.
Pointing to the great promise renewables hold for affordably mitigating climate change and enhancing energy security, the report warns governments to reduce policy uncertainties that are acting as brakes on greater deployment.
It said that renewable electricity additions over the next five years will top 700 gigawatts (GW) - more than twice Japan's current installed power capacity.
They will account for almost two-thirds of net additions to global power capacity - that is, the amount of new capacity that is added, minus the scheduled retirements of existing power plants.
The report sees the share of renewable energy in global power generation rising to over 26 per cent by 2020 from 22 per cent in 2013 - a remarkable shift in a very limited period of time.
By 2020, the amount of global electricity generation coming from renewable energy will be higher than today's combined electricity demand of China, India and Brazil.
The report says the geography of deployment will increasingly shift to emerging economies and developing countries, which will make up two-thirds of the renewable electricity expansion to 2020.
The report says that the financing remains key to achieving sustained investment. Besides regulatory barriers, grid constraints, and macroeconomic conditions pose challenges in many emerging economies.
