Biomass Power

Biomass power is power obtained from the energy in plants and plant-derived materials, such as food crops, grassy and woody plants, residues from agriculture or forestry, and the organic component of municipal and industrial wastes. Biomass power provides two valuable services: it is the second most important source of renewable energy in the United States and it is an important part of our waste management infrastructure. In the future, farms cultivating high-yielding energy crops (such as trees and grasses) will significantly expand our supply of biomass. These energy crops, coupled with high-efficiency conversion technologies, can supplement our consumption of fossil fuels and help us respond to global climate change concerns.
Wood has been used for energy longer than any other biomass source and today is still the largest biomass energy resource. The largest source of energy from wood is pulping liquor or "black liquor," a waste product from processes of the pulp, paper, and paperboard industry. Biomass energy can also be derived from waste and from alcohol fuels. Waste energy is the second-largest source of biomass energy. The main contributors of waste energy are municipal solid waste, manufacturing waste, and landfill gas.
Biomass can be used for direct heating (such as burning wood in a fireplace or wood stove), for generating electricity, or can be converted directly into liquid fuels to meet transportation energy needs.

Truck unloading wood chips that will fuel the Tracy Biomas Plant, Tracy, California.Electricity generated from biomass is also called biopower. Biopower facilities use many different technologies; the most common is burning of wood or other biomass feedstocks to produce steam which then is used to drive turbines and produce electricity. Some generators use a mix of biomass and fossil fuels to generate electricity, while others burn methane, a product of the natural decay of organic materials. In the United States, the pulp and paper industries are major producers of biopower, using residues from paper production to produce electricity for industrial plant use.
Biomass power is close to a carbon-neutral electric power generation option — biomass absorbs carbon dioxide from the atmosphere during its growth and then emits an equal amount of carbon dioxide when it is processed to generate electricity. Thus, biomass fuels "recycle" atmospheric carbon, and may reduce global warming impacts. Biopower facilities produce fewer other pollutants than equivalent fossil fuel power facilities.
Biofuels are liquid fuels produced from plants. The two most common types of biofuels are ethanol and biodiesel. Ethanol is an alcohol, the same as in beer and wine. It is made by fermenting any biomass high in carbohydrates through a process similar to beer brewing. The majority of ethanol produced in the United States is made from corn. Current research is exploring ways to efficiently convert cellulose (agricultural waste, forest residue, municipal solid waste, and energy crops) to ethanol. Ethanol is mostly used as a fuel additive for vehicles to increase octane and cut down carbon monoxide and other smog-causing emissions. Biodiesel is made by processing vegetable oil, animal fat, or recycled cooking grease with alcohol or other chemicals. It can be used as an additive (typically 20%) to reduce vehicle emissions or in its pure form as a renewable alternative fuel for diesel engines.




Biomass and biofuels resource potential in the conterminous United States.

Because biomass power is produced from plant sources, it can potentially be produced almost anywhere in the United States.
While biomass is a renewable energy resource, it can have both negative and positive environmental impacts. It may reduce emissions and pollutants, but factory farming of biomass crops can reduce biodiversity and negatively impact wildlife habitat. Municipal solid waste may contain toxins which could cause pollution if it is used as a biomass feedstock. As with other renewable resources, use of appropriate technology will promote the most positive environmental impacts.