Bioenergy
Bioenergy basics
Arkansas' bioenergy resources
Bio-fuels
Bio-energy incentives
Other sources of bioenergy
information
Bioenergy Basics
(Source:
U.S. Department of Energy)
The term bioenergy, or biomass, refers to all the Earth's vegetation and many products and co-products that come from it. Biomass is the oldest known source of renewable energy—humans have been using it since we discovered fire—and it has high energy content. The energy content of dry biomass ranges from 7,000 Btus/lb for straws to 8,500 Btus/lb for wood. Domestic biomass resources include agricultural and forestry wastes, municipal solid wastes, industrial wastes, and terrestrial and aquatic crops grown solely for energy purposes, known as energy crops.
Biomass is an attractive energy source for a number of reasons. First, it is a renewable energy source as long as we manage vegetation appropriately. Biomass is also more evenly distributed over the earth's surface than finite energy sources, and may be exploited using less capital-intensive technologies. It provides the opportunity for local, regional, and national energy self-sufficiency across the globe. And energy derived from biomass does not have the negative environmental impact associated with non-renewable energy sources. To learn more about biomass and bioenergy, visit the Department of Energy's National Biofuels Program website.
The map below shows biomass potential for the U.S.
According to the fact sheet Arkansas Biobased Fuels, Power, and Products, "Arkansas has an estimated total installed biomass capacity of 152 megawatts, primarily from timber residues. To increase biofuels activity, the state's Advanced Biofuels Tax Credit Act This income tax credit—only applicable to advanced biofuels like ethanol and methanol that are made from waste—allows a 30% tax credit toward the cost of equipment necessary to produce the biofuels such as ethanol and methanol.
Arkansas has an excellent biomass resource potential. An estimated 19.8 billion kWh of electricity could be generated using renewable biomass fuels in Arkansas. This is enough electricity to fully supply the annual needs of 1,979,000 average homes, or 150 percent of the residential electricity use in Arkansas. These biomass resource supply figures are based on estimates for five general categories of biomass: urban residues, mill residues, forest residues, agricultural residues, and energy crops. Of these potential biomass supplies and the quantities cited below, most forest residues, agricultural residues, and energy crops are not presently economic for energy use.
Wood is the most commonly used biomass fuel for heat and power. The most economic sources of wood fuels are usually urban residues and mill residues. Urban residues used for power generation consist mainly of chips and grindings of clean, non-hazardous wood from construction activities, woody yard and right-of-way trimmings, and discarded wood products such as waste pallets and crates. Local governments can encourage segregation of clean wood from other forms of municipal waste to help ensure its re-use for mulch, energy, and other markets. Using clean and segregated biomass materials for electricity generation recovers their energy value while avoiding landfill disposal. Mill residues, such as sawdust, bark, and wood scraps from paper, lumber, and furniture manufacturing operations are typically very clean and can be used as fuel by a wide range of biomass energy systems. The estimated supplies of urban and mill residues available for energy uses in Arkansas are 667,000 and 4,705,000 dry tons per year, respectively.
Wood is the most commonly used biomass fuel for heat and power. Photo: NREL
Forest residues include underutilized logging residues, imperfect commercial trees, dead wood, and other non-commercial trees that need to be thinned from crowded, unhealthy, fire-prone forests. Because of their sparseness and remote location, these residues are usually more expensive to recover than urban and mill residues. The estimated supply of forest residues for Arkansas is 1,738,000 dry tons per year.
Agricultural residues are the biomass materials remaining after harvesting agricultural crops. These residues include wheat straw, corn stover (leaves, stalks, and cobs), orchard trimmings, rice straw and husks, and bagasse (sugar cane residue). Due to the high costs for recovering most agricultural residues, they are not yet widely used for energy purposes; however, they can offer a sizeable biomass resource if supply infrastructures are developed to economically recover and deliver them to energy facilities. An estimated 984,000 dry tons per year is available from corn stover and wheat straw in Arkansas.
Agricultural residue, such as this corn stover, can serve as a source for biomass. Photo: NREL
Energy crops are crops developed and grown specifically
for fuel. These crops are carefully selected to be fast-growing,
drought and pest resistant, and readily harvested alternative
crops. Energy crops include fast-growing trees, shrubs,
and grasses such as hybrid poplars, hybrid willows, and
switchgrass, respectively. In addition to environmental
benefits, energy crops can provide income benefits for
farmers and rural land owners. For Arkansas, the production
potential for energy crops is estimated at 5,510,000 million
dry tons per year.
For more information on Arkansas bioenergy resoruce, see Arkansas Biomass Resource Assessment, a study funded by a grant from the Department of Energy, through the Southern States Energy Board, to the Arkansas Energy Office (AEO). Partners in the project include AEO, Arkansas Department of Environmental Quality, and the Arkansas Forestry Commission. The purpose of this study is to inform public policy makers and agency program planners, private sector entrepreneurs, equipment vendors, and potential investors, public utilities so that they can more effectively quantify target feedstocks and identify target locations for bioenergy systems in the state of Arkansas.