Biomass is material of plants and animals that can be used for energy. This includes using wood from trees, waste from plants  and manure from livestock. Biomass can be used to generate electricity, light, heat, motion and fuel. Converting biomass energy into useable energy has many environmental benefits. It uses waste materials that are usually dumped, and uses up methane (a greenhouse gas). Fuels such as ethanol can be made from biomass and used as an alternative to petrol to power motor cars.