Biomass is plant or animal material used to produce heat and to fuel power stations. It is also used to produce biofuels for transportation. It includes wood and wood processing waste, agricultural crops and waste, manure and sewage and natural solid waste from paper, cotton and food. Burning plant based biomass releases CO2, however, it is considered carbon-neutral as the source of the biomass captures almost the same amount of CO2 through photosynthesis while growing as is released when it is burned.

In 2019, power capacity using biomass as a fuel source was about 134GWs, equivalent to about 2% of the global generation mix. This is an increase from 106GWs in 2015 when it represented 1.7% of the mix.