Biomass

Biomass refers to energy stored in biological materials that can be used to generate heat, electricity and biofuels. Examples of biomass include wood, agricultural crops for alcohol fuels, solid waste, and landfill gas (primarily hydrogen gas). Industrial biomass can be grown from different types of plants including miscanthus, switchgrass, hemp, corn, poplar, willow, sorghum, sugarcane, and a few tree species, such as eucalyptus and oil palm. Biomass alcohol fuel, or ethanol, is derived mostly from corn and is used as an oxygenate in gasoline.

Biological materials absorb carbon dioxide (CO2) from the air as they grow, and when the biomass is burned, or decomposes through natural means, it emits carbon back into the atmosphere. ¹ This allows for a "closed carbon cycle" that results in a marked decrease in life cycle greenhouse gas emissions as compared to petroleum. Although fossil fuels originate in ancient biomass, they are not considered biomass by definition because they contain carbon that has been "out" of the carbon cycle for a long time.

The United States receives 45 billion kilowatt-hours of electricity from biomass, about 1.2 percent of the nation's total electric sales. The US also gets nearly four billion gallons of ethanol, about two percent of the liquid fuel used in cars and trucks.

Using biomass as an energy source offers many advantages over petroleum: it is more evenly distributed over the Earth, can be accessed through less intrusive means, and it represents a renewable resource. ² The most common technique used to generate energy from biomass is through direct combustion, but biomass can be used in three main ways:
1. In the form of gas through gasifiers for thermal applications
2. In the form of methane gas to run gas engines and produce power
3. Through combustion to produce steam and thereby power ³