Long-term global prospects continue to improve for generation from renewable energy sources, natural gas, and nuclear power. Renewables are the fastest-growing source of energy for electricity generation, with average increases of 2.9%/year from 2012 to 2040. Nonhydropower renewable resources are the fastest-growing energy sources for new generation capacity in both the OECD and non-OECD regions. Nonhydropower renewables accounted for 5% of total world generation in 2012; their share in 2040 is 14% in the IEO2016 Reference case, with much of the growth coming from wind power. After renewable energy sources, natural gas and nuclear power are the next fastest-growing sources of electricity generation. <a href="http://www.eia.gov/forecasts/ieo/exec_summ.cfm" rel="nofollow">www.eia.gov/forecasts/ieo/exec_summ.cfm</a>