Renewable energy supplied approximately 17 percent of global final energy consumption in 2010 and roughly eight percent of this total came from modern renewable energy sources, including hydropower, wind, solar, geothermal, biofuels, and modern biomass. In the power sector renewables supplied approximately 20 percent of global electricity, including 15 percent from hydropower. Countries such as Brazil and Iceland have demonstrated that it is possible to run power systems predominantly by renewable energy. Germany has demonstrated the feasibility of making an energy system transition to renewables by increasing its share of renewable power production to nearly 20 percent in two decades.

The share of renewable energy in global final energy consumption is increasing rapidly. Already more than half of annual capacity additions in the power sector are accounted for by renewables, resulting in a doubling of the share a decade ago. In 2011, 41 gigawatts (GW) of wind, 30 GW of hydropower, 28 GW of solar PV and approximately 5 GW of other renewable power generation capacity was added, out of less than 200 GW in total annual power generation capacity additions. These facts suggest that renewables are gaining traction as a primary source of power generation—but, as with prior energy transitions, the timescale for a shift in the energy mix is measured in decades.