Biomass Feedstocks for Biopower:
Background and Selected Issues
Kelsi Bracmort
Analyst in Agricultural Conservation and Natural Resources Policy
October 6, 2010
Congressional Research Service
7-5700
www.crs.gov
R41440
CRS Report for Congress
P
repared for Members and Committees of Congress
Biomass Feedstocks for Biopower: Background and Selected Issues
Summary
Biopower—a form of renewable energy—is the generation of electric power from biomass
feedstocks. Biopower, which comprised about 1% of electricity generation in 2008, may reduce
greenhouse gas emissions, provide energy security, and promote economic development. A large
range of feedstocks can be used, from woody and herbaceous biomass to agricultural residues.
Each feedstock has technical and economic advantages and challenges compared to fossil fuels.
Unlike wind or solar energy, a biopower plant is considered to be a baseload power source
because some biomass feedstocks can be used for continuous power production. However,
ensuring a sustainable supply of biomass feedstocks is a major challenge. Although there are
multiple biopower technologies, few of them except combustion have been deployed at
commercial scale nationwide.
Federal policymakers are supporting biopower through feedstock supply analysis and biopower
technology assessments. However, there is limited comprehensive data about the type and amount
of biomass feedstock available to meet U.S. biopower needs at a national level. If the use of
dedicated biomass feedstocks to generate biopower were to develop into a sizeable industry,
concerns would likely include the effect of the industry on land use (i.e., how much land would it
take to grow the crops needed to fuel or co-fuel power plants) and the effect on the broader
economy, including farm income and food prices. To date, these have not been issues: most
existing biomass feedstocks have been waste products generated by the forest products industry
or by farms, or municipal solid waste for which combustion served as both a disposal method and
a source of energy.
Growing crops for use as a power source would be different from using waste. Under generally
accepted assumptions regarding crop yields and energy content, approximately 31 million acres—
roughly the amount of land in farms in Iowa—would be needed to supply enough biomass
feedstock to satisfy 6% of total 2008 U.S. electricity retail sales. When added to the amount of
land needed to meet the requirements of the Renewable Fuel Standard (RFS), a federally
mandated transportation fuel requirement, the potential impacts could be significant: the RFS
already consumes 35% of the nation’s corn crop, and its requirements will triple between 2010
and 2022 (although much of this fuel will come from feedstocks other than corn).
Beyond land use and economic impacts, others are concerned that the use of biomass feedstocks
to generate biopower, particularly through combustion, could add to greenhouse gas (GHG)
emission levels and exacerbate climate change concerns. They fear that certain areas may be
unsustainably harvested to meet biomass feedstock demand, or that less biomass may be left for
other purposes (e.g., wood and paper products). The concerns exist partly because biomass used
for biopower does not face the same constraints as biomass used for liquid transportation fuels
under the RFS. In addition, the idea that biomass combustion is carbon-neutral is under scrutiny.
The Environmental Protection Agency has not exempted biomass combustion emissions from the
Prevention of Significant Deterioration and Title V Greenhouse Gas Tailoring Rule. The rule sets
thresholds for GHG emissions that define when permits are required for new and existing
industrial facilities. It is unclear what the rule would mean for biomass combustion plants, since
determinations of the best available control technologies (BACT)—a pollution control standard
mandated by the Clean Air Act—will be provided in another rulemaking. Those who consider
biomass combustion emissions to be biogenic (produced by living organisms), and thus carbon-
neutral over time, argue that these emissions should be exempted from the rule.
Congressional Research Service
Biomass Feedstocks for Biopower: Background and Selected Issues
Contents
Introduction ................................................................................................................................ 1
What Kind of Biomass Is Available for Biopower? ...................................................................... 2
From Biomass to Biopower ......................................................................................................... 4
Carbon Balance........................................................................................................................... 7
Implications for Legislation ...................................................................................................... 10
Conclusion................................................................................................................................ 11
Figures
Figure 1. Biopower Conversion Processes ................................................................................... 6
Figure 2. Biopower and Biofuel Technology Pipeline .................................................................. 6
Figure 3. Carbon Balance of Energy............................................................................................ 8
Tables
Table 1. General Classification of Biomass.................................................................................. 3
Table 2. Biomass Feedstock Growing Area Required to Produce Biopower ................................. 7
Appendixes
Appendix A. Biomass Feedstock Characteristics for Biopower Generation ................................ 13
Appendix B. Biopower R&D Authorizations ............................................................................. 22
Contacts
Author Contact Information ...................................................................................................... 27
Congressional Research Service
Biomass Feedstocks for Biopower: Background and Selected Issues
Introduction
The production of bioenergy—renewable energy derived from biomass—could potentially
increase national energy security, reduce greenhouse gas emissions, and contribute to rural
economic growth. Legislative, research, and industrial attention have focused on the production
of bioenergy in the form of liquid transportation fuels (e.g., corn-based ethanol).1 Biopower—the
production of electricity from biomass feedstocks—may require new national policies or
incentives if Congress decides to encourage its development.
Biopower, or biomass power, comprised about 1% of electricity generation in 2008.2 It was the
third-largest renewable energy source for electricity generation in that year, after conventional
hydroelectric power and wind.3 The Department of Energy’s (DOE’s) Energy Information
Administration (EIA) projects that electricity generation from biomass will grow from 0.9% of
total generation in 2008 to 5.5% in 2035.4 The DOE reference case for this projection assumes
extension of federal tax credits, state requirements for renewable electricity generation, and the
loan guarantee program in the Energy Policy Act of 2005 (EPAct05; P.L. 109-58) and the
American Recovery and Reinvestment Act of 2009 (ARRA; P.L. 111-5).
Current concerns for accelerating biopower growth include the need for a continuously available
feedstock supply, a commercial-scale facility to generate the biopower, and market certainty for
investors and purchasers alike. Improved feedstock availability, technological advancements, and
new forms of economic support could increase the relative contribution of biopower to meeting
U.S. energy demand.
One reason for the projected growth of biopower is the fuel’s ability to be used in a baseload
power plant. Baseload power is the minimum amount of electric power delivered or required over
a given period of time at a steady rate. If a plant operates as a baseload plant, the plant can run
continually except for maintenance and outages. With sufficient feedstock supplies, a biopower
plant could provide “firm” power for baseload needs (and long-term contracts would reduce risk).
In contrast, wind and solar energy require either a form of power storage, such as batteries, or a
backup power source, such as natural gas turbines, in order to provide firm power.
Power generation from biomass is not limited to a specific feedstock and therefore is relatively
flexible in terms of fuel suppliers. Each region of the country can pursue biomass feedstocks that
are native and readily available (e.g., corn stover in the Midwest, hybrid poplar in the Northwest,
switchgrass in the Southeast). The economic climate for biopower dictates that biopower plants
1 The Renewable Fuel Standard, a mandate to ensure that domestic transportation fuel contains a specified volume of
biofuels, is one reason most legislative and administrative efforts have focused on development of biofuels for
transportation. For more information, see CRS Report R40155, Renewable Fuel Standard (RFS): Overview and Issues,
by Randy Schnepf and Brent D. Yacobucci.
2 U.S. Energy Information Administration, Annual Energy Review 2009, DOE/EIA-0384(2009), August 2010,
http://www.eia.doe.gov/aer/elect.html.
3 U.S. Energy Information Administration, Renewable Energy Annual 2008 Edition, August 2010,
http://www.eia.doe.gov/cneaf/solar.renewables/page/rea_data/rea_sum.html. Biopower constituted roughly 14.4% of
electricity generation from renewable energy sources in 2008, preceded by conventional hydroelectric power and wind,
which constituted roughly 67% and 14.5%, respectively.
4 U.S. Energy Information Administration, Annual Energy Outlook 2010, DOE/EIA-0383(2010), Washington, DC,
April 2010, http://www.eia.doe.gov/oiaf/aeo/. The bulk of this increase is expected to come from growth in co-firing
operations. Co-firing is the combustion of a supplementary fuel (e.g., biomass) and coal concurrently.
Congressional Research Service
1
Biomass Feedstocks for Biopower: Background and Selected Issues
should be located in close proximity to feedstocks to reduce transportation costs, which can be
significant.5 Furthermore, existing combustion plants can be retrofitted for biopower production;
power from these plants could use existing transmission infrastructure. Financing and siting of
new transmission infrastructure could add uncertainty to a proposed project.
The availability and cost of biomass feedstocks determine the amount of biopower that can be
produced nationally. An overarching concern is maintaining a sustainable biomass feedstock
supply.6 If feedstocks are collected without regard to replenishment, or in an otherwise
unsustainable manner, biopower enterprises may lead to natural resource deterioration such as
soil erosion or the depletion of forested land. The Renewable Fuel Standard (RFS), expanded
under the Energy Independence and Security Act of 2007 (EISA; P.L. 110-140), mandates a
minimum volume of biofuels to be used in the national transportation fuel supply each year.
Under the RFS, biomass used for renewable fuel for transportation purposes cannot be removed
from federal lands, and the law excludes crops from forested lands.7 Thus far, biomass used for
biopower is not subject to the same constraints as biomass used for liquid transportation fuels
under the RFS. Additionally, feedstock diversity is a formidable challenge to biopower growth,
because cultivation, harvest, storage, and transport vary according to the feedstock type. Another
challenge is accounting for the amount of feedstock available for biopower production due to
market fluctuations and weather variability.
In considering congressional action to broaden legislative authorities for sustainable biopower
production, an understanding of the various biomass feedstocks and challenges to biopower
production could be useful to policymakers. This report provides analyses of commonly
discussed biomass feedstocks and their relative potential for power generation. Additional
biopower issues—feedstock accessibility, the biomass power plant carbon-neutrality debate, and
unintended consequences of legislative activities to promote bioenergy—are also discussed.
What Kind of Biomass Is Available for Biopower?
The type, amount, and costs of biomass feedstocks available for biopower will largely determine
whether biopower can thrive as a major renewable energy alternative. There is limited
comprehensive data on the amount of biomass feedstocks available to meet current and future
biopower needs at a national level. The supply data available is generally evaluated in terms of
meeting biofuel demand. Some may argue that feedstock assessments for biofuels are adequate
for biopower purposes, as the same feedstock may be used to meet both biofuel and biopower
demands. Information that identifies which feedstocks exhibit the most potential for power
5 Pew Center on Global Climate Change , Biopower, December 2009, http://www.pewclimate.org/docUploads/
Biopower%20final%2011%2009.pdf. Certain analysis indicates that feedstock supply should be located within a 50-
mile radius to avoid excessive transportation costs: Marie E. Walsh, Robert L. Perlack, and Anthony Turhollow et al.,
Biomass Feedstock Availability in the United States: 1999 State Level Analysis, Oak Ridge National Laboratory,
January 2000, http://bioenergy.ornl.gov/resourcedata/index.html.
6 Executive Order 13514 defines sustainability as the creation and maintenance of conditions that allow humans and
animals to exist in productive harmony, and that permit fulfilling the social, economic, and other requirements of
present and future generations. For more information, see CRS Report R40974, Executive Order 13514: Sustainability
and Greenhouse Gas Emissions Reduction , by Richard J. Campbell and Anthony Andrews.
7 For more information on biomass definitions, see CRS Report R40529, Biomass: Comparison of Definitions in
Legislation, by Kelsi Bracmort and Ross W. Gorte.
Congressional Research Service
2
Biomass Feedstocks for Biopower: Background and Selected Issues
generation in the near and long term is also scarce.8 Furthermore, ideal or feasible locations
where feedstocks may be grown are not well assessed. The potential inclusion of genetically
modified dedicated energy crops or selective breeding for bioenergy purposes may alter the
amount of biomass feedstock available for biopower production (and may alter land use).
Additional legislative action concerning financial support of biopower may depend on better data
to estimate the economic viability of biopower plants nationwide.9 Costs associated with biomass
storage and transportation to a biopower plant, as well as other economic and environmental
considerations, are among the factors assessed in individual biopower plant feasibility studies.
These factors are key to determining which biomass feedstocks can be used.
In addition to economics, biological characteristics play a large role in determining the suitability
of any type of biomass. Biomass is organic matter that can be converted into energy. Plants use
photosynthesis to store energy (carbon-based molecules) within cell walls, and that energy is
released when the biomass undergoes a biological process such as anaerobic digestion, or a
chemical process such as combustion. Biomass can include land- and water-based vegetation
(e.g., trees, algae), as well as other organic wastes (see Table 1).
Table 1. General Classification of Biomass
Biomass groups
Biomass sub-groups, varieties and species
Wood and woody biomass
Coniferous or deciduous (gymnosperm or angiosperm); stems,
branches, foliage, bark, chips, lumps, pellets, briquettes, sawdust,
sawmill and other wastes from various woody species
Herbaceous and agricultural biomass
Annual or perennial and field-based or process-based such as:
—grasses and flowers (alfalfa, arundo, bamboo, bana, brassica,
cane, miscanthus, switchgrass, timothy, others);
—straws (barley, bean, flax, corn, mint, oat, rape, rice, rye,
sesame, sunflower, wheat, others);
—other residues (fruits, shel s, husks, hulls, pits, pips, grains,
seeds, coir, stalks, cobs, kernels, bagasse, food, fodder, pulps,
cakes, others)
Aquatic biomass
Marine or freshwater algae and microalgae; macroalgae (blue,
green, blue-green, brown, red); seaweed, kelp, lake weed, water
hyacinth, others
Animal and human biomass wastes
Bones, meat-bone meal, chicken litter, various manures, others
Contaminated biomass and industrial biomass
Municipal solid waste, demolition wood, refuse-derived fuel,
wastes (semi-biomass)
sewage sludge, hospital waste, paper-pulp sludge and liquors,
waste papers, paperboard waste, chipboard, fibreboard, plywood,
wood pallets and boxes, railway sleepers, tannery waste, others
Biomass mixtures
Blends from the above varieties
Source: Stanislav V. Vassilev, David Baxter, and Lars K. Andersen, et al., “An Overview of the Chemical
Composition of Biomass,” Fuel, vol. 89 (2010), pp. 913-933. Adapted by CRS.
8 Some of this information may be provided in a forthcoming update to the frequently cited DOE/USDA Billion-Ton
Study, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton
Annual Supply, April 2005, http://www1.eere.energy.gov/biomass/pdfs/final_billionton_vision_report2.pdf.
9 In September 2010 the National Renewable Energy Laboratory released a comprehensive mapping application that
may provide better data to compare biomass feedstock and biopower by location. National Renewable Energy
Laboratory, “NREL Releases BioEnergy Atlas—A Comprehensive Biomass Mapping Application,” press release,
September 28, 2010, http://www.nrel.gov/news/press/2010/891.html
Congressional Research Service
3
Biomass Feedstocks for Biopower: Background and Selected Issues
Several types of feedstocks can be used as a fuel source for electric power generation. Primary
biomass feedstocks are materials harvested or collected directly where they are grown (e.g.,
grains). Secondary biomass feedstocks are by-products of the processing of primary feedstocks
(e.g., corn stover). Tertiary biomass feedstocks include post-consumer residues and wastes (e.g.,
construction and demolition waste). Appendix A shows the energy value, crop yield, advantages,
disadvantages, and general comments for selected biomass feedstocks and fossil fuels for
comparison.
Biomass would have to be grown in enormous quantities if it is to be used as a power source to
satisfy a significant portion of national energy demand. For example, approximately 31 million
acres—roughly the amount of land in farms in Iowa—of managed crops with a yield of 6 dry tons
per acre per year would be needed to supply enough biomass feedstock to satisfy 6% of total
2008 U.S. electricity retail sales.10 Quintessential biomass crops grown specifically for energy
generation (i.e., dedicated energy crops) are being considered to meet energy demand. Dedicated
energy crops may possess several desirable characteristics: high yield, low energy input to
produce, low cost, low nutrient requirements, low contaminant level, pest resistance, and low
fertilizer input.11
From Biomass to Biopower
Biomass can be converted to biopower via thermo-chemical and bio-chemical conversion
processes. These processes include combustion (or firing), pyrolysis, gasification, and anaerobic
digestion (see box, below, and Figure 1). The technologies are at varying stages of maturity (see
Figure 2). The choice of conversion technique selected for a specific biomass feedstock results in
differing amounts of useful energy recovered and forms for that energy.12 The systems can range
substantially in scale. Small-scale systems (or modular units) may be an optimal choice for rural
areas with limited electricity demand. Large-scale systems may be more economically suitable in
more urbanized areas or near grid connections if feedstocks are ample.
The volume of biomass feedstock supply necessary to run a biopower plant depends on the
feedstock’s energy content—the less the energy value, the more volume is needed. The growing
area needed to produce the biomass that will supply a biopower plant is contingent not only on
the energy value of the feedstock, but also on the power plant capacity, the power plant efficiency,
and the feedstock yield (see Table 2). Power plant capacity is the maximum output of power,
commonly expressed in millions of watts (megawatts, MW), that generating equipment can
supply over a certain time period. Power plant efficiency is the amount of electric energy
produced per unit of feedstock input. In general, the higher the yield of the biomass feedstock, the
less growing area is required to produce a MW of power. Also, less biomass is needed to support
power plants with high efficiency rates.
10 CRS calculations based on 2008 total U.S. retail electricity sales available at http://www.eia.doe.gov/electricity/esr/
esr_sum.html. Power plant capacity factor was assumed to be 80% with 988 growing acres required per megawatt; see
http://bioenergy.ornl.gov/resourcedata/powerandwood.html. The yield, six dry tons/acre, is similar to what may be
achieved by switchgrass. Land in farms data for Iowa obtained from the 2007 Census of Agriculture, available at
http://www.agcensus.usda.gov/Publications/2007/Online_Highlights/County_Profiles/Iowa/cp99019.pdf.
11 Peter McKendry, “Energy Production from Biomass (Part 1): Overview of Biomass,” Bioresource Technology, vol.
83 (2002), pp. 37-46.
12 Peter McKendry, “Energy Production from Biomass (Part 1): Overview of Biomass,” Bioresource Technology, vol.
83 (2002), pp. 37-46.
Congressional Research Service
4
Biomass Feedstocks for Biopower: Background and Selected Issues
Selected Biopower Conversion Processes Defined
A. Combustion is the burning of biomass in a power plant. The biomass is burned to heat a boiler and create steam.
The steam powers a turbine, which is connected to a generator to produce electricity. Existing plant efficiencies are in
the low 20% range, although methods are available to advance efficiency to upwards of 40%. (“Efficiency” describes
which percentage of the feedstock processed is actually converted to electricity.) Approximately 180 combustion
units for biomass are in operation using wood and agricultural residues as the feedstock.
Co-firing, the simultaneous firing of biomass with coal in an existing power plant, is the most cost-effective biopower
technology. Co-firing with biomass using existing equipment is less expensive than constructing a new biopower plant.
The existing plant does require retrofitting to accept the biomass entering the plant. Certain air particulates
associated with coal combustion are reduced with co-firing, as less coal is being burned. Co-firing has a generation
efficiency in the 33%-37% range; coal-fired plants have efficiencies in the 33%-45% range. Approximately 78 co-firing
units for biomass are in operation using wood and agricultural residues as the feedstock.
B. Gasification is the heating of biomass into synthesis gas (syngas, a mixture of hydrogen and carbon monoxide) in
an environment with limited oxygen. The flammable syngas can be used in a combined gas and steam turbine to
generate electricity. Generation efficiencies range from 40% to 50%. One challenge for gasification is feedstock
logistics (e.g., cost to ship or transport the feedstock to the power plant). A wide variety of feedstocks could undergo
gasification, including wood chips, sawdust, bark, agricultural residues, and waste. There are currently no gasification
systems for biomass at any scale.
C. Pyrolysis is the chemical breakdown of a substance under extremely high temperatures (400°C -500°C) in the
absence of oxygen. There are fast and slow pyrolysis technologies. Fast pyrolysis technologies could be used to
generate electricity. Fast pyrolysis of biomass produces a liquid product, pyrolysis oil or bio-oil, that can be readily
stored and transported. The bio-oils produced from these technologies would be suitable for use in boilers for
electricity generation. One of the challenges with pyrolysis is that the bio-oil produced tends to be low-quality
relative to what is needed for power production. Commonly used feedstock types for pyrolysis include a variety of
wood and agricultural resources. There are currently no commercial-scale pyrolysis facilities for biomass.
D. Anaerobic digestion (not shown in Figure 1) is a biological conversion process that breaks down a feedstock
(e.g., manure, landfill waste) in the absence of oxygen to produce methane, among other outputs, that can be
captured and used as an energy source to generate electricity. Anaerobic digestion systems have historical y been
used for comparatively smaller-scale energy generation in rural areas. Feedstocks suitable for digestion include
brewery waste, cheese whey, manure, grass clippings, restaurant wastes, and the organic fraction of municipal solid
waste, among others. Generation efficiency is roughly 20%-30%. Approximately 150 anaerobic digesters are in
operation using manure as the feedstock.
Sources: Oak Ridge National Laboratory, Biomass Energy Data Book: Edition 2, ORNL/Tm-2009/098, December 2009,
http://cta.ornl.gov/bedb/pdf/BEDB2_Full_Doc.pdf. International Energy Agency, Biomass for Power Generation and CHP,
ETE03, January 2007, http://www.iea.org/techno/essentials3.pdf. National Association of State Foresters, A Strategy for
Increasing the Use of Woody Biomass for Energy, Portland, ME, September 2008, http://www.stateforesters.org/files/
NASF-biomass-strategy-FULL-REPORT-2009.pdf. Sally Brown, "Putting the Landfill Energy Myth to Rest," BioCycle,
May 2010. John Balsam and Dave Ryan, Anaerobic Digestion of Animal Wastes: Factors to Consider, ATTRA—National
Sustainable Agriculture Information Service, IP219, 2006, http://attra.ncat.org/attra-pub/anaerobic.html. Jennifer
Beddoes, Kelsi Bracmort, and Robert Burns et al., An Analysis of Energy Production Costs from Anaerobic Digestion
Systems on U.S. Livestock Production Facilities, USDA Natural Resources Conservation Service, October 2007. Personal
communication with Robert Baldwin, National Renewable Energy Laboratory, 2010. Personal communication with
Lynn Wright, biomass consultant working with Oak Ridge National Laboratory. For more information on anaerobic
digestion, see CRS Report R40667, Anaerobic Digestion: Greenhouse Gas Emission Reduction and Energy Generation, by
Kelsi Bracmort.
Congressional Research Service
5
Biomass Feedstocks for Biopower: Background and Selected Issues
Figure 1. Biopower Conversion Processes
Source: Peter McKendry, “Energy Production from Biomass (Part 2): Conversion Technologies,” Bioresource
Technology, vol. 83 (2002), pp. 47-54. Adapted by CRS.
Figure 2. Biopower and Biofuel Technology Pipeline
Source: Electric Power Research Institute, Biopower Generation: Biomass Issues, Fuels, Technologies, and
Research, Development, Demonstration, and Deployment Opportunities, February 2010.
Congressional Research Service
6
Biomass Feedstocks for Biopower: Background and Selected Issues
Table 2. Biomass Feedstock Growing Area Required to Produce Biopower
Power plant capacity factor (%) 80
80
80
80
90
90
90
90
Power
plant
efficiency
(%) 25 30
35 40 25 30 35 40
Crop yield (dry tons/acre/year)
(see Appendix A)
Growing Acres Required per MW
1
5930 4941
4235 3706 6671 5559 4765 4169
2
2965 2471
2118 1853 3335 2780 2382 2085
3
1977 1647
1412 1235 2224 1853 1588 1390
4
1482 1235
1059 927 1668 1390 1191 1042
5
1186
988
847 741 1334 1112 953 834
6
988 824
706 618 1112 927 794 695
7
847 706
605 529 953 794 681 596
8
741 618
529 463 834 695 596 521
9
659 549
471 412 741 618 529 463
10
593 494
424 371 667 556 476 417
Source: Department of Energy, Relationship Between Power Plant Efficiency and Capacity and Tons Biomass
Required and Acres Required, Lynn Wright, http://bioenergy.ornl.gov/resourcedata/powerandwood.html.
Notes (from original source): Raw numbers have been used in the above table. Calculations assume dry biomass
at 8500 btu/lb = 19.75 Gj/MG and 3413 btu/kWH = 0.0036 Gj/kWh.
Rule of thumb relationship of 1000 acres and 5000 dry tons per MW is based on 80% capacity, 30% efficiency,
and 5 dry ton/acre/year yield. A program goal would be to have a relationship of 500 acres and 4200 dry tons
per MW at 90% capacity, 40% efficiency, and 8 dry ton/acre/year yield.
Yields of 1-2 dry ton/acre/year are common for natural forests but could also represent residue levels available
from high yield plantations. Yields of 3-4 dry ton/acre/year are common for pulpwood pine plantations. Yields of
4-7 dry ton/acre/year are being observed in woody crop and herbaceous crop plantings without irrigation,
5dt/ac/yr still best average estimate. Yields of 7-10 dry ton/acre/year are being observed in some energy crop
plantings with best clones or varieties and/or with irrigation or high water tables.
Total planted area or growing area required to supply a biomass facility should be used rather than area actually
being harvested in any given year. While these are the same for a herbaceous crop harvested annual y, they differ
significantly for a woody crop harvested once every few years. Calculation of the annual harvested area for a
wood crop requires knowing both the yield (dry ton/acre/year) and the harvest age of the woody crop. This
varies from project to project.
Carbon Balance
Certain sources of biomass (e.g., forestry products, dedicated energy crops) are deemed by some
to be carbon-neutral because they absorb enough CO2 during their growth period to balance the
release of CO2 when they are burned for energy (see Figure 3). The term carbon-neutral is
defined as the combustion or oxidation of matter which causes no net increase in GHG emissions
on a lifecycle basis.13 One controversial aspect of the carbon neutrality debate, and what requires
13 Section 201 of the Energy Independence and Security Act of 2007 (EISA; P.L. 110-140) defines lifecycle emissions
as follows: “(H) LIFECYCLE GREENHOUSE GAS EMISSIONS.—The term ‘lifecycle greenhouse gas emissions’
means the aggregate quantity of greenhouse gas emissions (including direct emissions and significant indirect
(continued...)
Congressional Research Service
7
Biomass Feedstocks for Biopower: Background and Selected Issues
further study, is the magnitude in which these plant-derived feedstocks will be used for energy
production and thus whether the feedstock supply can be sustained (or replenished) without
environmental impairment. Some examples of environmental impairment involve disrupting
forest ecosystems by cutting down large amounts of trees, or affecting the climate by not
capturing GHGs emitted during bioenergy production. If the feedstocks are not replenished so
that they can absorb CO2, or GHG emissions are not captured from a biopower plant, the resulting
GHG releases can be akin to that of carbon-positive fossil fuels.
Figure 3. Carbon Balance of Energy
Source: John A. Matthews, “Carbon-Negative Biofuels,” Energy Policy, vol. 36 (2008), pp. 940-945; Biopact, “The
Strange World of Carbon-Negative Bioenergy: The More You Drive Your Car, the More You Tackle Climate
Change,” 2007, http://news.mongabay.com/bioenergy/2007/10/strange-world-of-carbon-negative.html. Adapted
by CRS.
Notes: Carbon-positive fuels are burned, releasing CO2 into the atmosphere. Carbon-neutral fuels absorb CO2
as they grow and release the same carbon back into the atmosphere when burnt. Carbon-negative fuels absorb
CO2 as they grow and release less than this amount into the atmosphere when used as fuel, either through
directing part of the biomass as biochar back into the soil or through carbon capture and sequestration.
The designation of biomass combustion as carbon-neutral has come under scrutiny recently due
to the Prevention of Significant Deterioration and Title V Greenhouse Gas Tailoring Rule
(Tailoring Rule) finalized in May 2010 by the U.S. Environmental Protection Agency (EPA). The
Tailoring Rule does not exempt emissions from biomass combustion.14 The rule grants
exemptions not based on source category (e.g., fossil fuels, biomass), but on carbon tonnage
(...continued)
emissions such as significant emissions from land use changes), as determined by the Administrator, related to the full
fuel lifecycle, including all stages of fuel and feedstock production and distribution, from feedstock generation or
extraction through the distribution and delivery and use of the finished fuel to the ultimate consumer, where the mass
values for all greenhouse gases are adjusted to account for their relative global warming potential.” 42 U.S.C.
§7545(o)(1). For more information on lifecycle emissions, see CRS Report R40460, Calculation of Lifecycle
Greenhouse Gas Emissions for the Renewable Fuel Standard (RFS), by Brent D. Yacobucci and Kelsi Bracmort.
14 EPA’s decision on biomass combustion and biogenic activities is described in further detail on pages 419-422 of the
final rule, available at http://www.epa.gov/nsr/documents/20100413final.pdf. For more information on the final rule,
see CRS Report R41212, EPA Regulation of Greenhouse Gases: Congressional Responses and Options, by James E.
McCarthy and Larry Parker.
Congressional Research Service
8
Biomass Feedstocks for Biopower: Background and Selected Issues
emitted from a facility. Beginning in January 2011, the first phase of the rule applies to any
project that emits at least 75,000 tons per year of carbon dioxide equivalent (CO2e). One reason
EPA did not exempt the biomass industry from the Tailoring Rule requirements is lack of
information demonstrating the costs and administrative burdens the biopower industry would face
if subject to the permitting requirements.15 EPA issued a call for information in July 2010 to
request comment on possible accounting approaches for biogenic emissions under the Tailoring
Rule.16 It is unclear what the Tailoring Rule would mean for biomass combustion plants, since the
best available control technologies (BACT)—a pollution control standard mandated by the Clean
Air Act—are determined by individual states with EPA guidance on a case-by-case basis.17
State perspectives on the inclusion of emissions from biomass combustion in the Tailoring Rule
are divided.18 Some states contend that the inclusion of biomass combustion will jeopardize
renewable energy development due to excessive permitting requirements and fees, while other
states argue that not including biomass combustion will aggravate climate change over time.
Advocates of not exempting biomass combustion from the Tailoring Rule assert that not all
biomass is carbon-neutral.19 They point out that some types of biomass, particularly biomass
coming from waste streams, settle closer to the carbon-neutral and carbon-negative side of the
scale. However, cutting down trees from a forest to burn in a power plant without regard to
replenishing the tree stand is carbon-positive. Moreover, these advocates argue, fossil fuels are
still used to farm, harvest, and transport the biomass for biopower purposes, potentially negating
the carbon neutrality over the lifecycle.
Advocates of a complete biomass combustion exemption from the Tailoring Rule contend that
biopower plant emissions add no new carbon to the atmosphere because only residuals,
byproducts, and thinnings, or waste materials that would decay, are used.20 Furthermore, they
argue that CO2 released during biomass combustion is neutral because it is re-absorbed by
growing biomass. Thus, measuring the emissions released during biomass combustion does not
capture the entire biomass emission portfolio. The American Forest & Paper Association asserts
that not exempting biomass combustion from the Tailoring Rule “jeopardizes public and private
investment in biomass-based renewable energy, which is fundamental to existing and future green
jobs in rural communities hit hard by the economic downturn.”21
15 Environmental Protection Agency, “Prevention of Significant Deterioration,” 75 Federal Register 31590, June 3,
2010.
16 U.S. Environmental Protection Agency, Call for Information on Greenhouse Gas Emissions Associated with
Bioenergy and Other Biogenic Sources, July 9, 2010, http://www.epa.gov/climatechange/emissions/
biogenic_emissions.html.
17 BACT is an emissions limitation which is based on the maximum degree of control that can be achieved. It is a case-
by-case decision that considers energy, environmental, and economic impact. BACT can be add-on control equipment
or modification of the production processes or methods. BACT may be a design, equipment, work practice, or
operational standard if imposition of an emissions standard is infeasible.
18 Energy Washington, States Split on Whether Biomass Should Be Exempt from GHG Permits, September 22, 2010.
19 Nathanael Greene, Scientists to Congress & Obama: Count the Carbon in Biomass, Natural Resources Defense
Council, May 24, 2010, http://switchboard.nrdc.org/blogs/ngreene/scientists_to_congress_obama_c.html.
20 Personal communication with Bob Cleaves, CEO, Biomass Power Association, October 1, 2010.
21 American Forest & Paper Association, “EPA’S Tailoring Rule Undermines Renewable Energy From Biomass,
Harms Rural Communities and Puts American Jobs at Risk,” press release, May 14, 2010, http://www.afandpa.org/
pressreleases.aspx?id=1364.
Congressional Research Service
9
Biomass Feedstocks for Biopower: Background and Selected Issues
Looking forward, these competing parties may be concerned with the designation of biomass
combustion as carbon-neutral because of congressional discussion and proposals to expand the
biomass definition in energy legislation. Expanding the biomass definition could increase the
amount of land eligible for biomass removal. The biomass definition in the Energy Independence
and Security Act of 2007 (EISA; P.L. 110-140) for the Renewable Fuel Standard (RFS) excludes
biomass removal from federal lands, and crops from forested lands are excluded as a biofuel
feedstock.22 However, the Food, Conservation, and Energy Act of 2008 (2008 farm bill, P.L. 110-
246) includes biomass from federal lands as a biofuel feedstock. The RFS addresses the carbon
balance issue of liquid transportation biofuels by requiring advanced biofuels to have lower
lifecycle emissions relative to petroleum products. EPA was responsible for determining how the
lifecycle emissions analysis would be carried out. The debate about how EPA should address the
lifecycle emissions analysis, especially the land use component, was controversial.23 While the
RFS focuses on liquid transportation fuels, legislation has been introduced to create a renewable
electricity standard (RES).24 Many of the same biomass concerns, and thus carbon neutrality
concerns, expressed for the RFS are applicable to an RES.
There are other aspects associated with the designation of biomass energy as carbon-neutral,
many of which are beyond the scope of this report.
Implications for Legislation
Biopower straddles at least three legislative areas: agriculture, energy, and environment. The main
benefits that agricultural legislation could provide, as argued by proponents for biopower, are to
ensure an adequate feedstock supply, maintain productive field conditions during biomass growth
and harvest, and assist farmers who participate in the bioenergy market. Energy objectives, as
stated by supporters, involve establishing a robust biopower technology platform and providing
financial and technical assistance for biopower technology pioneers. Protecting the environment
throughout the biomass-to-biopower conversion is the major environmental objective, including
monitoring GHG emissions released during energy production.
As a candidate for large-scale energy use, the biopower industry may challenge Congress to
address its evolving needs on a frequent basis until biopower is a seasoned energy alternative.
One frequent topic of discussion for renewable energy is the “uneven” playing field for certain
feedstocks. Supporters of pre-selected feedstocks for biopower production argue that resources
can be targeted to that handful of feedstocks that display the most potential for bioenergy
production. Opponents contend that pre-selecting certain feedstocks makes it difficult for other
feedstocks to obtain the support needed to show their competitiveness as a biopower source.
Congress currently supports biopower with the Renewable Energy Production Tax Credit (PTC)
and the Investment Tax Credit (ITC). The PTC is an incentive to business developers of
22 The Renewable Fuel Standard (RFS) is a provision established by the Energy Policy Act of 2005 requiring gasoline
to contain a minimum amount of fuel produced from renewable biomass. For more information on the RFS, see CRS
Report R40155, Renewable Fuel Standard (RFS): Overview and Issues, by Randy Schnepf and Brent D. Yacobucci.
23 For more information, see CRS Report R40460, Calculation of Lifecycle Greenhouse Gas Emissions for the
Renewable Fuel Standard (RFS), by Brent D. Yacobucci and Kelsi Bracmort.
24 For more information on the renewable electricity standard debate, see CRS Report R40565, Biomass Resources:
The Southeastern United States and the Renewable Electricity Standard Debate, by Richard J. Campbell.
Congressional Research Service
10
Biomass Feedstocks for Biopower: Background and Selected Issues
renewable energy projects producing electricity, whereby a developer can apply for a credit
against taxes for each kilowatt-hour of renewable energy produced.25 The ITC is an incentive for
domestic investment in renewable energy plants and equipment.26 Moving forward, there may be
unintended consequences of legislation that supports biopower. For example, initial USDA
regulations for implementing the Biomass Crop Assistance Program (BCAP) led to shifting
sawmill residues from products (especially particleboard) to energy rather than increasing
utilization of forest waste or planting biomass feedstocks for bioenergy.27
Legislative efforts are under way to further support the biopower industry. One relevant
legislative effort is the creation of a renewable electricity standard (RES) to encourage renewable
energy use, and thus production of renewable energy such as biopower. One bill that includes a
federal RES is the American Clean Energy Leadership Act of 2009 (ACELA, S. 1462), an energy
policy bill reported out of the Senate Committee on Energy and Natural Resources on July 16,
2009.28 The RES would require utilities that sell electricity to consumers to obtain a percentage of
their annual electricity supply from renewable energy sources or energy efficiency, starting at 3%
in 2011 and rising incrementally to 15% by 2021. S. 1462 identifies biomass as an eligible
renewable source. H.R. 890, S. 433, and S. 3021 are other bills that would create a federal RES.
Additionally, H.R. 2454, the American Clean Energy and Security Act, also contains provisions
that would support biopower, such as transmission planning and net metering, along with an
RES.29
Conclusion
While there remain significant challenges to its future development, biopower production could
increase in the coming years to satisfy U.S. renewable energy demand (e.g., state renewable
portfolio standards). Generation of electricity from biopower plants has advantages over other
renewable sources such as wind and solar. Biopower plants are considered baseload plants. Also,
multiple biomass feedstocks can be used to generate electricity. Some disadvantages of using
biomass for electricity generation include the cost to transport the biomass to the biopower plant,
less biomass to be used for other purposes, and environmental tensions such as whether biomass
combustion is carbon-neutral. A sustainable supply of biomass feedstocks could be favorable to
biopower growth.
Questions remain about how to encourage biopower production and simultaneously address
technological, environmental, and agricultural concerns. Because market uncertainties exist for
biopower, the agricultural community may hesitate to grow the amount of biomass feedstocks
needed to support large-scale biopower production. Moreover, most biopower technologies, with
the exception of combustion and co-firing systems, have yet to reach commercial status.
25 26 U.S.C. § 45.
26 26 U.S.C. § 48.
27 For more information on BCAP, see CRS Report R41296, Biomass Crop Assistance Program (BCAP): Status and
Issues, by Megan Stubbs. BCAP provides financial assistance to producers or entities that deliver eligible biomass
material to designated biomass conversion facilities for use as heat, power, biobased products, or biofuels.
28 For more information on the proposed RES in S. 1462, see CRS Report R40837, Summary and Analysis of S. 1462:
American Clean Energy Leadership Act of 2009, As Reported, coordinated by Mark Holt and Gene Whitney.
29 For more information, see CRS Report R40890, Summary and Analysis of S. 1733 and Comparison with H.R. 2454:
Electric Power and Natural Gas, by Stan Mark Kaplan.
Congressional Research Service
11
Biomass Feedstocks for Biopower: Background and Selected Issues
Improvements to the remaining biopower conversion technologies may arise when there is a solid
market for biopower. There is no federal mandate requiring the production of biopower, although
more than 25 states have implemented state renewable portfolio standards or goals that include
biopower. Furthermore, legislative uncertainty has contributed to the reluctance to develop
biopower. Additional assurances of federal support, whether technical, economic, or through
renewable mandates, could spur commitments by investors, the technology community, and
others.
Congressional Research Service
12
Biomass Feedstocks for Biopower: Background and Selected Issues
Appendix A. Biomass Feedstock Characteristics for Biopower Generation
Energy Value
Feedstock Type
Btu/lb (dry)a Feedstock
Yieldb Selected
Advantages
Selected
Disadvantages Commentsc
Woody Biomass
Willow
7,983-8,497 4-8 dry tons/acre/year
• High yield potential • Requires specialized
• Very high future
(example of a wood crop grown as a
harvested on 2-4 year
harvesting equipment
yield potential
bush type or “coppice” crop in high
cycle
• Grown for several
with genetic
density plantings as dedicated
cycles before
• High density plantings are
selection
bioenergy crop)
replanting
costly to establish
• Innovative harvest
• Select varieties
• U.S. experience and
equipment is
easily replicated by
varieties of willow
available
cloning
currently limited to
Northeast
• Many woody
• Easy to automate
hardwood crops
planting and
• Must be harvested in
can be grown as
harvest as a row
winter to obtain regrowth
bush type crops
crop
for several cycles
• Economic yields
• Short harvest cycle • Agricultural site
obtained on
for wood
preparation needed for
marginal to good
successful establishment
• Farmers can grow
cropland
and harvest
• Susceptibility of some
• Less fertilization
willow varieties to insects
• Low ash content
required than
and diseases may require
agricultural crops
occasional chemical
applications
Hybrid poplar
8,183-8,491 3-7
dry
tons/acre/year;
• High yield potential • No immediate return on
• Very high future
(example of a fast growing hardwood
harvested on 5-15 year
investment
yield potential
grown as a row crop for bioenergy
cycles
• Select varieties
with genetic
or multiple purposes)
easily replicated by
• Susceptibility of some
selection
cloning
hybrid poplar varieties to
insects and diseases may
• Innovative harvest
• Easy to automate
require occasional
equipment is
planting and
chemical applications
under
harvest as a row
development
crop
• Agriculture-type site
preparation needed for
• Economic yields
• Can be stored on
successful establishment
obtained on
stump until needed
marginal to good
• Regrowth after harvest is
• Relatively low-
cropland
possible but replanting
CRS-13
Biomass Feedstocks for Biopower: Background and Selected Issues
Energy Value
Feedstock Type
Btu/lb (dry)a
Feedstock Yieldb Selected
Advantages
Selected
Disadvantages Commentsc
maintenance crop
with superior clones is
recommend
• Improvements for
bioenergy will also
likely benefit the
pulp and paper
industry
Loblolly pine
8,000-9,120 3-7
dry
tons/acre/year;
• 30 million acres of
• Pines cannot currently be
• Well suited for
(example of fast-growing softwood
harvested every 20-40
southern pines
cloned; standard breeding
thermal
grown as a row crop for bioenergy
years
already are being
and family selection
technologies to
or multiple purposes )
managed in
techniques must be used
generate
southern U.S.
to improve yield
electricity and
ethanol
• Somewhat higher
• Pines are mostly hand
energy value than
planted, since planted as
• Conversion to
poplars and willows
rooted seedlings; Limited
liquid fuels is
automation is possible
possible with acid
• Grows better than
hydrolysis and as a
poplars and other
• Agricultural type site
co-product of pulp
hardwoods on
preparation needed for
fiber production
marginal coastal
rapid early growth
plains and
• Less fertilization
flatwoods soils
required than for
agricultural crops
• Valuable to
landowners as a
low-intensity crop
with multiple
markets
Pine chips
8,000-9,120
10-20 dry tons/acre of
• Relatively
• High retrieval cost when
• An expanded
(example of forest residues from
on-site residues following
inexpensive if chips
tops and branches
ethanol industry
timber and fiber harvests)
logging; harvested every
produced at the
collected in forest due to
using wood can
20-40 years
roadside as a by-
labor-intensive collection
also be an
product of wood
and transportation
additional source
processing
of biopower as a
• Tops and branches may
co-product
• Infrastructure to
not be accessible or
handle forest
environmentally
residues exists
sustainable to remove for
chipping, depending on
location and soil type
CRS-14
Biomass Feedstocks for Biopower: Background and Selected Issues
Energy Value
Feedstock Type
Btu/lb (dry)a
Feedstock Yieldb Selected
Advantages
Selected
Disadvantages Commentsc
Mill residue
7,000-10,000
Highly variable depending • Easily available and
• Nearly all mill residues
• Most mill residues
(from both sawmills and pulp mills)
on operating size of the
accessible
are currently being used
will continue to be
mill
in wood products such as
used at or near
• Inexpensive
particleboard and paper,
the site where
• Infrastructure to
as fuel for heat or
wood is processed
handle feedstock
biopower, or to make
though at higher
exists
mulch
energy costs,
more might shift
to on-site
bioenergy
production
Herbaceous Biomass
Miscanthus
7,781-8,417 4-7
dry
tons/acre/year
• Once established,
• No immediate harvest;
• Perennial grass
(highly productive grass in Europe)
current U.S. average
can be harvested
takes one to three years
• Established
4-12 dry tons/acre/year
annual y for 15-20
to be established
vegetatively by
has been observed for
years before having
to replant
• Not a native species
planting divided
delayed harvest yields in
rhizome pieces
Europe
•
•
Low fertilizer
Testing as a bioenergy
requirements
feedstock limited to the
• Higher yields are
last 10 years (most
likely to occur on
• Drought-tolerant
research conducted in
well-drained soils
Europe)
suitable for annual
• Very high yield
row crops
potential with
• Thick-stem and moisture
adequate water
content of 30 to 50% in
• Suitable for
late fall requires
thermochemical
• Long growth
specialized harvesting
conversion
season in mid-U.S.
equipment
processes, such as
• Giant miscanthus is
combustion, if
• Planting of rhizomes
sterile, thus not
harvest is delayed
requires specialized
invasive
until late winter
equipment
Switchgrass
7,754-8,233
4-9 dry tons/acre/year
• Suitable for growth • No immediate harvest;
• Native perennial
(example of several possible perennial
range in research trials
on marginal land
takes two to three years
grass
warm-season grasses)
to be established
• Relatively high,
• Can be used for
reliable
• May require annual
gasification,
productivity across
fertilization to optimize
combustion or
a wide geographical
yields, but at relatively
pyrolysis
range
low levels
technologies to
CRS-15
Biomass Feedstocks for Biopower: Background and Selected Issues
Energy Value
Feedstock Type
Btu/lb (dry)a
Feedstock Yieldb Selected
Advantages
Selected
Disadvantages Commentsc
•
generate
Low water and
• Annual harvest must
nutrient
occur over a relatively
electricity or for
requirements
short window of time
biochemical
each fall
conversion to
• Provides wildlife
ethanol
cover and erosion
• Year-round storage is
control
needed if switchgrass is
• Research for
only feedstock for a
bioenergy
• Can be grown and
bioenergy facility
feedstock began in
harvested with
the 1980s
existing farm
• Energy content diminishes
equipment
over year if not kept dry
• Planted by seeding • Ash content can be high
• Low moisture
content if
harvested in late
fal (15% to 20%)
• Few major insect
or disease pests
Sorghum—varieties selected for
7,476-8,184
4-10 dry tons/acre/year
• Suitable for warm
• Yields more variable than
• Sweet, grain, and
biomass production
and dry growing
switchgrass, with rainfall
silage sorghums
(similar to a tall thin stalked forage
Higher yields observed
regions
differences
are more suitable
sorghum crop)
for ethanol
• Seed production
• Requires > 20 inches of
production with
delayed, thus
rainfall annually
higher sugar
produces more
content
biomass
• Annual crop, thus more
expense and work to
• Susceptibility to
• Annual crop, thus
replant each year
anthracnose
immediate return
disease of some
on investment
genotypes
• Grows across most
of eastern and
central U.S., not
frost limited
Sugarcane/Energycane
7,450-8,349
Yields exceeding 10 dry
• Takes
• Planting locations limited
• Literature mostly
tons/acre common
approximately one
to a few states in the
centers on its use
year to become
South and Hawaii
for ethanol
CRS-16
Biomass Feedstocks for Biopower: Background and Selected Issues
Energy Value
Feedstock Type
Btu/lb (dry)a
Feedstock Yieldb Selected
Advantages
Selected
Disadvantages Commentsc
established
• Must be replanted every 4 • The bagasse
• Has very high yield
to 5 years
(residue once juice
potential in
is extracted from
• Planting is vegetative
tropical, semi-
the sugarcane)
(stalks are laid down)
tropical and
may be used for
rather than by seed
subtropical regions
biopower e.g.,
of world
• Vulnerable to bacterial,
frequently used in
fungal, viral, and insect
Brazil
• A multi-purpose
pests
crop-producing
• Research ongoing
sugar (or ethanol)
• Crop must be harvested
to hybridize to
and biopower
green and dewatered or
achieve cold
feedstock
stored like silage
tolerance
• Drought-adapted
Aquatic Biomass
Algae 8,000-10,000
for
Estimates not available
• Cultivation
• Relatively little R&D
• Considered a
algal mass; 16,000 for biopower
strategies can
investment regarding
third-generation
for algal oil and
minimize or avoid
feedstock, biopower
bioenergy source
lipids
competition with
conversion, and
arable land and
infrastructure
• Mainly considered
nutrients used for
for biofuel
conventional
purposes;
agriculture
however, some
scientists are
• Can use waste
studying its
water, produced
biopower
water, and saline
potential, both
water, reducing
directly or via
competition for
methane
limited freshwater
productiond
supplies
• Can recycle carbon
from CO2-rich flue
emissions from
stationary sources
including power
plants and other
industrial emitters
CRS-17
Biomass Feedstocks for Biopower: Background and Selected Issues
Energy Value
Feedstock Type
Btu/lb (dry)a
Feedstock Yieldb Selected
Advantages
Selected
Disadvantages Commentsc
Agricultural Biomass and Animal Wastes
Corn stover
7,587-7,967
Stover amounts could
• Cultivation
• Harvesting and
• Corn grain and
range from 3-4.5 dry
techniques are
transportation
stover use has
tons/acre/year in fields
established
infrastructure not yet
reinvigorated the
producing 100-150
established
food-fuel debate
bushels of grain/acre
• Using a resource
that has previously
• Excessive removal may
• Can be used for
gone unused
lead to soil erosion and
gasification,
nutrient runoff
combustion, or
• Stover conversion
pyrolysis
process could be
• Requires high level of
technologies for
added to grain-to-
nutrients and fertile soils
electricity or
ethanol facilities
biochemical
processes for
biofuels
Wheat straw
6,964-8,148
2.6 tons dry tons/acre
• Cultivation
• Harvesting and
• Can be used for
techniques are
transportation
gasification,
established
infrastructure not yet
combustion or
established
pyrolysis
• Using a resource
technologies to
that has previously
• Excessive removal may
generate
gone unused
lead to soil erosion and
electricity or
nutrient runoff
biochemical
processes to
biofuels
Sugarcane bagasse (residue once juice 7,450-8,349 14%-30%
of
total • Sugarcane takes
• Bagasse availability limited • Literature mostly
is extracted from the sugar cane; see
sugarcane yield
approximately one
to a few states in the
centers on its use
above for sugarcane)
year to become
South and Hawaii
for ethanol
established
• Ash content can be high
• The bagasse is
• Bagasse is collected
used to power
as part of the main
sugarcane mills in
crop
many parts of the
world.
Cattle manure
8,500
Based on manure
• Using a resource
• Technology to convert
• Well suited for
excretion rate of cow
that is generally
manure to electricity is
anaerobic
regarded as a waste
expensive
digestion to
product with little
generate
to no value
• Difficult for some
electricity
CRS-18
Biomass Feedstocks for Biopower: Background and Selected Issues
Energy Value
Feedstock Type
Btu/lb (dry)a
Feedstock Yieldb Selected
Advantages
Selected
Disadvantages Commentsc
•
agricultural producers to
Using a resource
that has
sell power to utilities due
undesirable
to economics and utility
environmental
company col aboration
impacts if
improperly
managed
• Col ection systems
established for
dairy manure
• Water and air
quality
improvement
Industrial Biomass
Municipal solid waste (MSW)
5,100 (on an as
1,643 lbs/person/year
• A resource
• Could serve as a
• Not considered by
arrived basis)
available in
disincentive to separate
some as a
abundant supply
and recycle certain waste
renewable energy
feedstock because
• Diverts MSW from • Air emissions are strictly
some of the waste
landfill disposal
regulated to control the
materials are made
release of toxic materials
• Well-
using fossil fuels
often in MSW; toxins
commercialized
removed from air
• Well suited for
technology (waste-
emissions will be
combustion (waste
to-energy plants)
transferred to waste ash,
to energy plants),
which may require
gasification,
disposal as hazardous
pyrolysis, or
waste
anaerobic
digestion
• Costs are substantial y
technologies to
higher than landfill in most
generate
areas
electricity
Fossil Fuels
Coal
6,437-8,154 Not
applicable
• Established
• Limited resource
(low rank; lignite/sub-bituminous)
infrastructure
• Major source of mercury,
• Reliable
SO2, and NOx emissions
CRS-19
Biomass Feedstocks for Biopower: Background and Selected Issues
Energy Value
Feedstock Type
Btu/lb (dry)a
Feedstock Yieldb Selected
Advantages
Selected
Disadvantages Commentsc
• Relatively
• Main source of U.S.
inexpensive
greenhouse gas emissions
• Generates a tremendous
amount of waste ash that
likely contains a host of
hazardous constituents
Coal
11,587-12,875 Not
applicable
• Established
• Limited resource
(high rank; bituminous)
infrastructure
• Major source of mercury,
• Reliable
SO2 and NOx emissions
• Relatively
• Main source of U.S.
inexpensive
greenhouse gas emissions
• Generates a tremendous
amount of waste ash that
likely contains a host of
hazardous constituents
Oil
18,025-19,313 Not
applicable
• Established
• Limited resource
(typical distillate)
infrastructure
• Major source of SO2 and
• Reliable
NOx emissions
• Purchased in large
quantities from foreign
sources
Source: Compiled from various sources by CRS and Lynn Wright, biomass consultant working with Oak Ridge National Laboratory.
Notes: The information provided in this table are estimates for general use. Multiple factors including location, economics, and technical parameters will influence the data
on a case-by-case basis. Lynn Wright, biomass consultant working with Oak Ridge National Laboratory, provided the following comments: The infrastructure to handle
woody resources (both forest residues and plantation grown wood) already exists in the pulp and paper industry and can be easily used for the bioenergy industry. Most
woody biomass resources (whether forest residues or plantation grown wood) will be delivered as chips similar to current pulp and paper industry practices. However,
new equipment and harvest techniques may al ow delivery as bundles or whole trees in some situations. Wood resources such as chipped pine (softwoods) and hardwoods
and urban wood residues are already being used to generate electricity using direct combustion technologies, all woody feedstocks are well suited for all thermal
conversion technologies including combustion, gasification and pryolysis to generate electricity. Biopower can also be produced from the black liquor by-product of both
pulp and ethanol production. Clean wood chips from willow, hybrid poplar, and other hardwoods are also very suitable for conversion to liquid fuels using biochemical
conversion technologies.
a. Energy values for the following feedstocks were obtained from Oak Ridge National Laboratory, Biomass Energy Data Book: Edition 2, ORNL/Tm-2009/098, December
2009, http://cta.ornl.gov/bedb/pdf/BEDB2_Full_Doc.pdf; Table A.2 “Heat Content Ranges for Various Biomass Fuels”; willow, hybrid poplar, pine = Forest Residues -
softwoods, switchgrass, miscanthus (converted from kj/kg to Btu/lb) corn stover, sugarcane bagasse and wheat straw. Energy values for fossil fuels were obtained by
CRS-20
Biomass Feedstocks for Biopower: Background and Selected Issues
converting the heating values (GJ/t) provided in Jonathan Scurlock, Bioenergy Feedstock Characteristics, Oak Ridge National Laboratory, 2002, http://bioenergy.ornl.gov/
papers/misc/biochar_factsheet.html to an energy value (Btu/lb). The energy value for sawmill residue was obtained from Nathan McClure, Georgia Forestry
Commission, “Forest Biomass as a Feedstock for Energy Production,” oral presentation for Georgia Bioenergy Conference, August 2, 2006,
http://www.gabioenergy.org/ppt/McClure—Forest%20Biomass%20as%20a%20Feedstock%20for%20Energy%20Production.pdf. The energy value for algae was obtained
from Oilgae, “Answers to some Algae Oil FAQs—Heating Value, Yield ...,” February 2007, http://www.oilgae.com/blog/2007/02/answers-to-some-algae-oil-faqs-
heating.html. The energy value of manure on a dry ash-free basis was obtained from Texas Cooperative Extension, Manure to Energy: Understanding Processes, Principles
and Jargon, E-428, 2006, http://tammi.tamu.edu/ManurtoEnrgyE428.pdf. The manure heating value may be reduced by the ash and moisture content of the manure given
certain conditions. The energy value of municipal solid waste was obtained from C. Valkenburg, C.W. Walton, and B.L. Thompson, et al., Municipal Solid Waste (MSW)
to Liquid Fuels Synthesis, Volume 1: Availability of Feedstock and Technology, Pacific Northwest National Laboratory, PNNL-18144, December 2008, http://www.pnl.gov/
main/publications/external/technical_reports/PNNL-18144.pdf. The energy value for sorghum was obtained using a value for sudan grass, a closely related crop, from
the European PHYLLIS database http://www.ecn.nl/phyllis/dataTable.asp.
b. The harvest frequency is on an annual basis unless stated otherwise. Energy yield ranges for willows, poplars, pines, switchgrass, miscanthus, sugarcane, sugarcane
bagasse and sorghum were provided by Lynn Wright, biomass consultant working with Oak Ridge National Laboratory. Energy yields for miscanthus. and switchgrass
were also discussed with Jeffrey Steiner (USDA), August 2010. Energy yields for hybrid poplar were also obtained from Minnesota Department of Agriculture,
Minnesota Energy from Biomass, http://www.mda.state.mn.us/renewable/renewablefuels/biomass.aspx; Energy yield for pine chips (forest residues) was obtained from
calculations from data in David A. Hartman et al., Conversion Factors for the Pacific Northwest Forest Industry (Seattle, WA; Univ. of Washington, Institute of Forest
Products, no date), pp. 6, 47. Energy yield for corn stover was obtained from R.L Nielsen, Questions Relative to Harvesting & Storing Corn Stover, Purdue University,
AGRY-95-09, September 1995, http://www.agry.purdue.edu/ext/corn/pubs/agry9509.htm. Energy yield for wheat straw was obtained from Jim Morrison, Emerson
Nafziger, and Lyle Paul, Predicting Wheat Straw Yields in Northern Illinois, University of Illinois at Urbana-Champaign, 2007, http://cropsci.illinois.edu/research/rdc/dekalb/
publications/2007/PredictingWheatStrawYieldsFinalReportToExtensionMay2007.pdf; In general, it is assumed a dairy cow excretes 150lbs of manure/day based on the
American Society of Agricultural and Biological Engineers (ASABE) Manure Production and Characteristics Standard D384.2, March 2005. Energy yield for municipal
solid waste was calculated based on data from U.S. Environmental Protection Agency Office of Solid Waste http://www.epa.gov/osw/basic-solid.htm (In 2008, U.S.
residents, businesses, and institutions produced about 250 million tons of MSW, which is approximately 4.5 pounds of waste per person per day). Energy yield for
miscanthus in Europe was obtained from Clifton-Brown, J.C., Stampfl, P.A., and Jones, M.B., Miscanthus Biomass Production for Energy in Europe and Its Potential
Contribution to Decreasing Fossil Fuel Carbon Emissions. Global Change Biology, 10, (2004) pp. 509-518; Energy yield for siwtchgrass was obtained from McLaughlin, S.B.,
and Kszos, L.A., “Development of Switchgrass (panicum virgatum) as a bioenergy feedstock in the United States.” Biomass and Bioenergy 28 (2005) pp. 515-535.
Energy yield for sorghum was obtained from W.L. Rooney, et al, “Designing Sorghum as a Dedicated Bioenergy Feedstock.” Biofuels, Bioproducts, and Biorefining. 1,
(2007) pp.147-157; Energy yield for sugarcane/energycane obtained from http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=251543&pf=1 (a
web-published abstract of a book chapter written by Bransby et. al. and submitted for publication in February 2010); Energy yield for sugarcane baggase was obtained
from http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=254594&pf=1 (an abstract of a book chapter prepared by R. Viator, P. White, and E.
Richard, and entitled “ Sustainable Production of Energycane for Bio-energy in the Southeastern U.S.” submitted for publication by the Sugarcane Research Unit in
Houma, LA in August 2010).
c. For more information on the state of combustion, pyrolysis, gasification, and anaerobic digestion technologies, see the shaded text box on page 5.
d. For more information, see Stanford University, “Stanford Researchers Find Electrical Current Stemming from Plants,” press release, April 13, 2010,
http://news.stanford.edu/news/2010/april/electric-current-plants-041310.html; and John Ferrel and Valerie Sarisky-Reed, National Algal Biofuels Technology Roadmap, U.S.
Department of Energy Office of Energy Efficiency and Renewable Energy Office of the Biomass Program, May 2010, http://www1.eere.energy.gov/biomass/pdfs/
algal_biofuels_roadmap.pdf.
CRS-21
Biomass Feedstocks for Biopower: Background and Selected Issues
Appendix B. Biopower R&D Authorizations
R&D Authorizations
Congress has enacted numerous provisions that authorize the Departments of Energy (DOE) and
Agriculture (USDA) to conduct biopower research, development, and demonstration projects
(RD&D) and to support biopower commercial application efforts.30 At least eight public laws
contain one or more biopower provisions:
• P.L. 95-620, Powerplants and Industrial Fuel Use Act of 1978
• P.L. 96-294, Energy Security Act of 1980
• P.L. 106-224, Biomass Research and Development Act of 2000
• P.L. 107-171, Farm Security and Rural Investment Act of 2002
• P.L. 108-148, Healthy Forest Restoration Act of 2003
• P.L. 109-58, Energy Policy Act of 2005
• P.L. 110-140, Energy Independence and Security Act of 2007
• P.L. 110-246, Food, Conservation, and Energy Act of 2008
The public laws discussed in this section are summaries of provisions at the time of enactment to
illustrate the evolution of bioenergy policy. Some provisions may have been amended since
enactment. A comprehensive legislative history of current law is beyond the scope of this report.
1978-1980: Biopower Legislative Origin
Both the Powerplant and Industrial Fuel Use Act of 1978 (P.L. 95-620) and the Energy Security
Act of 1980 (P.L. 96-294) introduced the concept of biopower to the legislative arena. However,
the enacted legislation emphasized the use of biomass as a liquid fuel to reduce dependence on
imported petroleum and natural gas. Biomass used to generate electricity appears to have received
less legislative support compared to biomass use as a liquid fuel, based on the report language
and authorizations.
Powerplant and Industrial Fuel Use Act of 1978 (P.L. 95-620)
The legislative origin of biopower stems from the Powerplant and Industrial Fuel Use Act of
1978. The act aimed to restrict the use of oil and natural gas as fuel in an attempt to mitigate the
oil crisis of the mid-1970s by encouraging industries and utilities to reduce oil use. It required
new power plants to operate using coal or alternate fuel sources. Otherwise, the act did not
provide explicit support for biopower RD&D and commercial application.
30 National Renewable Energy Laboratory, Power Technologies Energy Data Book, NREL/TP-620-39728, August
2006, http://www.nrel.gov/analysis/power_databook/docs/pdf/39728_complete.pdf.
Congressional Research Service
22
Biomass Feedstocks for Biopower: Background and Selected Issues
• § 103(a)(6) - defines alternate fuel, in part, as electricity or any fuel, other than
natural gas or petroleum, from sources such as biomass, municipal, industrial or
agricultural wastes, wood, and renewable and geothermal energy sources.
Energy Security Act of 1980 (P.L. 96-294)
• § 203(4)(B) - defines biomass energy, in part, as energy or steam derived from
the direct combustion of biomass for the generation of electricity, mechanical
power, or industrial process heat.
• § 203(5)(B) - defines biomass energy project, in part, as any facility (or portion
of a facility) located in the United States which is primarily for the combustion of
biomass for generating industrial process heat, mechanical power, or electricity,
including cogeneration.
• § 203(19) - defines a small-scale biomass energy project as a biomass energy
project with an anticipated annual production capacity of not more than 1 million
gallons of ethanol per year, or its energy equivalent of other forms of biomass
energy.
• § 211(a) - requires DOE and USDA to collaborate on a biomass energy
production and use plan and on providing financial assistance for biomass energy
projects.
• § 251(a) - indirect reference to biopower; stipulates the establishment of
demonstration biomass energy facilities by the Secretary of Agriculture to exhibit
the most advanced technology available for producing biomass energy.
• § 252 - indirect reference to biopower; modifies § 1419 of the National
Agricultural Research, Extension, and Teaching Policy Act of 1977 (P.L. 95-113)
to better address biomass energy for RD&D purposes; authorizes the Secretary of
Agriculture to award grants for research related to, in part, the development of
the most economical and commercially feasible means of producing, collecting,
and transporting agricultural crops, wastes, residues, and byproducts for use as
feedstocks for the production of alcohol and other forms of biomass energy.
• § 255(a) - indirect reference to biopower; adds a Biomass Energy Educational
and Technical Assistance Program to Subtitle B of P.L. 95-113 to provide
technical assistance to producers for efficient use of biomass energy and
disseminate research results to producers about biomass energy, among other
things.
1981-1999: Biopower Legislation and Technology
Congress did not significantly address biopower during most of the 1980s and 1990s partially due
to stable conventional energy prices and supplies. Some biopower technologies emerged during
this time period with low success rates due to poor design and inadequate management (e.g.,
anaerobic digestion systems). Other reliable biopower technologies were developed during this
time period (e.g., biomass co-firing), but these could not compete economically with other energy
sources.
Congressional Research Service
23
Biomass Feedstocks for Biopower: Background and Selected Issues
2000-Present: Biopower Legislative Action
Described below are a variety of biopower provisions contained in public laws since 2000.
Although many of the provisions focus primarily on the use of biomass for liquid transportation
fuel, there is also legislative support for biopower. Both DOE and USDA have the authority to
conduct RD&D and support commercial application efforts for biopower. However, project
summaries and financial allotments indicate the majority of resources in recent years were
directed toward liquid fuels for transportation.31
Biomass Research and Development Act of 2000 (P.L. 106-224)
The Biomass Research and Development Act32 established a partnership between the USDA and
DOE for RD&D on the production of biobased industrial products. (This act was amended by the
Energy Policy Act of 2005, P.L. 109-58.) The original provisions included:
• § 303(2) - defines biobased industrial products to include fuels, chemicals,
building materials, or electric power or heat produced from biomass.
• § 305 - implicit reference to biopower; establishes the Biomass Research and
Development Board to coordinate research and development activities relating to
biobased industrial products; Board membership includes a representative from
DOE, USDA, Department of the Interior, the U.S. Environmental Protection
Agency, the National Science Foundation, and the Office of Science and
Technology Policy.
• § 306 - implicit reference to biopower; establishes the Biomass Research and
Development Technical Advisory Committee to, in part, advise the Biomass
Research and Development Board concerning the technical focus and direction of
requests for proposals issued under the Biomass Research and Development
Initiative
• § 307 - implicit reference to biopower; authorizes the Secretaries of Agriculture
and of Energy to, in part, competitively award grants, contracts, and financial
assistance to eligible entities that can perform research on biobased industrial
products. For example, grants may be rendered to an entity conducting research
on advanced biomass gasification and combustion to produce electricity
(§ 307(d)(2)(e)); related research in advanced turbine and stationary fuel cell
technology for production of electricity from biomass (§ 307(d)(2)(f)); biomass
gasification and combustion to produce electricity (§ 307(d)(3)(A)(v)); and any
research and development in technologies or processes determined by the
Secretaries, acting through their respective points of contact and in consultation
with the Biomass Research and Development Board (§ 307(d)(4)).
31 For information on biomass energy incentives, see CRS Report R40913, Renewable Energy and Energy Efficiency
Incentives: A Summary of Federal Programs, by Richard J. Campbell, Lynn J. Cunningham, and Beth A. Roberts
32 The Biomass Research and Development Act is Title III of the Agricultural Risk Protection Act of 2000 (P.L. 106-
224).
Congressional Research Service
24
Biomass Feedstocks for Biopower: Background and Selected Issues
Farm Security and Rural Investment Act of 2002 (P.L. 107-171)
• § 9003 - authorizes the Secretary of Agriculture to award grants to assist in
paying the development and construction costs of biorefineries in order to carry
out projects that demonstrate their commercial viability for converting biomass to
fuels or chemicals.
• § 9003(b)(2) - defines biorefinery as equipment and processes that convert
biomass into fuels and chemicals; and may produce electricity.
Healthy Forest Restoration Act of 2003 (P.L. 108-148)
• § 203 - establishes the Biomass Commercial Utilization Grant Program;
authorizes the Secretary of Agriculture to make grants to the owner or operator of
a facility that uses biomass as a raw material to produce one or more of several
outputs, including electric energy.
Energy Policy Act of 2005 (EPAct05; P.L. 109-58)
• § 931(f) - authorizes the Secretary of Energy, in consultation with the Secretary
of Agriculture, to implement rural demonstration projects that use renewable
energy technologies to assist in delivering electricity to rural and remote
locations from biomass.
• § 932 (b)(1) - authorizes the Secretary of Energy to conduct a program of RD&D,
and commercial application for bioenergy including biopower energy systems.
• § 932 (d)(B)(iv) - authorizes the Secretary of Energy to demonstrate the
commercial application of integrated biorefineries from the commercial
application of biomass technologies for energy in the form of electricity or useful
heat.
• § 941(a) - amends the definition for biobased product in P.L. 106-224 to mean an
industrial product (including chemicals, materials, and polymers) produced from
biomass, or a commercial or industrial product (including animal feed and
electric power) derived in connection with the conversion of biomass to fuel.
• § 941(d)(1) - modifies membership of the Biomass Research and Development
Technical Advisory Committee (P.L. 106-224 § 306); replaces an individual
affiliated with the biobased industrial products industry with an individual
affiliated with the biofuels industry; adds an individual affiliated with the
biobased industrial and commercial products industry; requires committee
members as described in P.L. 106-224, § 306(b)(1)(C), (D), (G), and (I) to have
expertise in ‘fuels and biobased products’ whereas previously members were to
have expertise in ‘biobased industrial products’.
• § 941(e)(1) - modifies the Biomass Research and Development Initiative (P.L.
106-224, § 307(a)) to focus on “research on, and development and demonstration
of, biobased fuels and biobased products, and the methods, practices and
technologies, for their production.” Previously the initiative focus was on
“research on biobased industrial products.”
Congressional Research Service
25
Biomass Feedstocks for Biopower: Background and Selected Issues
• § 941(e)(2) - adds to the Biomass Research and Development Initiative (P.L. 106-
224, § 307) an objectives section and a technical areas section, in addition to
other sections, that specify biobased fuels as a priority. For example, the initiative
is to support “product diversification through technologies relevant to production
of a range of biobased products (including chemicals, animal feeds, and
cogenerated power) that eventually can increase the feasibility of fuel production
in a biorefinery.”
Energy Independence and Security Act of 2007 (EISA; P.L. 110-140)
• § 231(1) - modifies EPAct05 § 931(b) by adding an authorization of $963 million
for FY2010. Section 931 of the EPAct05 authorizes the Secretary of Energy to
conduct programs of renewable energy RD&D, and commercial application.
• § 231(2) - modifies EPAct05 § 931(c)(2) to increase authorized funding for
FY2008 from $251 million to $377 million; Also modifies EPAct05 § 931(c)(3)
to increase authorized funding for FY2009 from $274 million to $398 million.
The Food, Conservation, and Energy Act of 2008 (2008 Farm Bill, P.L. 110-246)
• § 7526 - reauthorizes the Sun Grant program, which requires USDA to
coordinate with DOE and land-grant colleges and universities to provide grants
to the Sun Grant centers to enhance the efficiency of bioenergy and biomass
research and development programs.
• § 9001 - defines biorefinery as a facility that converts renewable biomass into
biofuels and biobased products; and may produce electricity.
• § 9008 - defines biobased product as an industrial product (including chemicals,
materials, and polymers) produced from biomass, or a commercial or industrial
product (including animal feed and electric power) derived in connection with
the conversion of biomass to fuel.
• § 9011 - establishes the Biomass Crop Assistance Program which provides
financial assistance to producers or entities that deliver eligible biomass material
to designated biomass conversion facilities for use as heat, power, biobased
products or biofuels.
• § 9012 - authorizes the Secretary of Agriculture, acting through the Forest
Service, to conduct a competitive R&D program to encourage use of forest
biomass for energy.
• § 9013(a)(2) - defines a community wood energy system as an energy system that
primarily services public facilities owned or operated by state or local
governments, including schools, town halls, libraries, and other public buildings;
and uses woody biomass as the primary fuel. The term includes single facility
central heating, district heating, combined heat and energy systems, and other
related biomass energy systems.
• § 9013(b) - establishes the Community Wood Energy Program and authorizes the
Secretary of Agriculture, acting through the Forest Service, to provide grants of
up to $50,000 for up to 50% of the cost for communities to plan and install wood
energy systems in public buildings.
Congressional Research Service
26
Biomass Feedstocks for Biopower: Background and Selected Issues
Author Contact Information
Kelsi Bracmort
Analyst in Agricultural Conservation and Natural
Resources Policy
kbracmort@crs.loc.gov, 7-7283
Congressional Research Service
27