The IEA published its medium-term renewable energy market report for the year. It said renewable energy resources like wind, solar and hydroelectric power will account for nearly 25 percent of the global power mix by 2018, greater than that expected from natural gas and nuclear power.
Chinese investments in renewable energy are expected to lead to the increase expected by 2018. That should offset slower growth expected from the European Union and the United States, which is in the midst of an oil and natural gas boom.
"As their costs continue to fall, renewable power sources are increasingly standing on their own merits versus new fossil-fuel generation," IEA Executive Director Maria van der Hoeven said in a Thursday statement.
The British government released energy statistics Thursday stating renewable energy use increased 10 percent during the first quarter of 2013 while electricity generated from natural gas fell to its lowest level in 15 years.
Van der Hoeven said the increased use in renewable energy as a whole did not mean governments can relax in terms of their low-carbon agendas.
"Worldwide subsidies for fossil fuels remain six times higher than economic incentives for renewables," she said.