“Biomass” is organic matter used as fuel. The fuel can be either a liquid or solid, such as chipped wood, energy crops like switchgrass, forest or agricultural residue or waste, manufacturing waste, (i.e., wood shavings from a furniture factory or a paper mill), wood pellets, sewage sludge, or construction and demolition waste. Pennsylvanians use biomass primarily to generate heat, either on the smaller residential scale or on the institutional scale. Biomass is primarily fired in boilers, similar to coal, natural gas or fuel oil. Liquid biomass fuels occur most often as ethanol and are typically used to supplement gasoline for vehicles.