Biomass energy fuels may include a wide variety of items, such as animal manure, landfill waste, wood pellets, vegetable oil, algae, crops like corn, sugar, switchgrass and other plant material -- even paper and household garbage.Biomass fuel can be converted directly into heat energy through combustion. In other cases, biomass is converted into another fuel source; examples include ethanol gasoline made from corn, or methane gas derived from animal waste.