Explanation: Data for 2013 shows that renewable electricity generation overtook natural gas to become the second largest source of electricity worldwide producing 22% of total electricity or 5,130 TWh. Some of the sources of renewable energy are: solar power, wind power, wave and tidal power, geothermal power, biomass and hydro power. Fossil fuels remained the bedrock of global electricity production with more than two-thirds (about 67%) of the total.