Renewable energy is energy generated from resources that are unlimited, rapidly replenished or naturally renewable such as wind, water, sun, wave and refuse, and not from the combustion of fossil fuels.

Renewable energy effectively uses natural resources such as sunlight, wind, tides and geothermal heat, which are naturally replenished. Renewable energy technologies range from solar power, wind power and hydroelectricity to biomass and biofuels for transportation. About 13 percent of primary energy comes from renewables, with most of this coming from traditional biomass like wood-burning.  Hydropower is the next largest source, providing 2-3%, and modern technologies like geothermal, wind, solar, and marine energy together produce less than 1% of total world energy demand. The technical potential for their use is very large, exceeding all other readily available sources.