Methane Capture: Options for Greenhouse
Gas Emission Reduction
Kelsi Bracmort
Analyst in Agricultural Conservation and Natural Resources Policy
Jonathan L. Ramseur
Analyst in Environmental Policy
James E. McCarthy
Specialist in Environmental Policy
Peter Folger
Specialist in Energy and Natural Resources Policy
Donald J. Marples
Specialist in Public Finance
September 17, 2009
Congressional Research Service
7-5700
www.crs.gov
R40813
CRS Report for Congress
P
repared for Members and Committees of Congress
Methane Capture: Options for Greenhouse Gas Emission Reduction
Summary
Research on climate change has identified a wide array of sources that emit greenhouse gases
(GHGs). Among the six gases that have generally been the primary focus of concern, methane is
the second-most abundant, accounting for approximately 8% of total U.S. GHG emissions in
2007. Methane is emitted from a number of sources. The most significant are agriculture (both
animal digestive systems and manure management); landfills; oil and gas production, refining,
and distribution; and coal mining.
As Congress considers legislation to address climate change by capping or reducing GHG
emissions, methane capture projects offer an array of possible reduction opportunities, many of
which utilize proven technologies. Methane capture projects (e.g., landfill gas projects, anaerobic
digestion systems) restrict the release of methane into the atmosphere. The methane captured can
be used for energy or flared. Methane capture challenges differ depending on the source. Most
methane capture technologies face obstacles to implementation, including marginal economics in
many cases, restricted pipeline access, and various legal issues.
Some of the leading methane capture options under discussion include market-based emission
control programs, carbon offsets, emission performance standards, and maintaining existing
programs and incentives. At present, methane capture technologies are supported by tax
incentives in some cases, by research and demonstration programs in others, by regulation in the
case of the largest landfills, and by voluntary programs. Congress could decide to address
methane capture in a number of different ways, including (1) determining the role of methane
capture in climate change legislation; (2) determining whether methane capture should be
addressed on an industry-by-industry basis; and (3) determining if current methane capture
initiatives will be further advanced with legislative action regardless of other facets of the climate
change policy debate. What role methane capture would play in prospective legislation to control
GHGs—whether methane sources would be included among those covered by a cap-and-trade
system, for example, whether they would be a source of emission offsets from sources not
covered by cap-and-trade, or whether their emissions might be subject to regulation—is among
the issues that Congress faces.
A few government programs have supported the capture of methane to mitigate climate change.
The Methane-to-Markets Partnership, administered by the Environmental Protection Agency
(EPA), is an international initiative to reduce global methane emissions. EPA also oversees a
variety of voluntary programs related to the Methane-to-Markets initiative (e.g., Coalbed
Methane Outreach Program, Natural Gas STAR Program, Landfill Methane Outreach Program,
AgSTAR Program).
This report discusses legislative alternatives for addressing methane capture, sources of methane,
opportunities and challenges for methane capture, and current federal programs that support
methane recovery.
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Methane Capture: Options for Greenhouse Gas Emission Reduction
Contents
Introduction ................................................................................................................................ 6
Policy Options for Addressing Methane Capture ......................................................................... 6
Market-Based Emission Control Programs ............................................................................ 6
Carbon Offsets ...................................................................................................................... 8
Emission Performance Standards .......................................................................................... 9
Maintain Existing Programs/Incentives ................................................................................. 9
Legislative Proposals Concerning Methane Capture .................................................................. 10
Methane: A Primer .................................................................................................................... 12
Global Warming Potential ................................................................................................... 13
Sources of Methane............................................................................................................. 13
Domestic ...................................................................................................................... 13
International.................................................................................................................. 14
Methane Use and Storage.................................................................................................... 15
Opportunities and Challenges for Methane Capture................................................................... 16
Agriculture.......................................................................................................................... 17
Landfill Gas........................................................................................................................ 17
Oil and Natural Gas ............................................................................................................ 18
Coalbed Methane ................................................................................................................ 19
Concerns Applicable to All Sources..................................................................................... 20
Federal Support for Methane Capture........................................................................................ 20
Methane-to-Markets Partnership ......................................................................................... 20
Voluntary Methane Programs .............................................................................................. 21
Federal Energy Management Program................................................................................. 21
Tax Incentives..................................................................................................................... 21
DOE Methane Hydrate Research and Development ............................................................. 22
Figures
Figure 1. 2007 U.S. Sources of Anthropogenic Methane Emissions ........................................... 14
Figure 2. U.S. Underground Natural Gas Storage Facilities, Close of 2007 ................................ 16
Tables
Table 1. Selected Sources of U.S. Methane Emissions and Potential Number of Entities
Subject to Emission Control Program....................................................................................... 7
Table 2. Selected Legislation Proposed in the 111th Congress Relevant to Methane .................... 11
Table 3. Top Five Methane-Emitting Countries in 2005 ............................................................. 15
Table 4. U.S. Methane Emissions by Source.............................................................................. 16
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Methane Capture: Options for Greenhouse Gas Emission Reduction
Appendixes
Appendix. World Methane Emissions by Sector in 2005............................................................ 24
Contacts
Author Contact Information ...................................................................................................... 25
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Methane Capture: Options for Greenhouse Gas Emission Reduction
Introduction
In the climate change policy debate, methane capture projects have garnered attention for their
ability to mitigate greenhouse gas emissions. Methane capture projects prevent the release of
methane, a potent greenhouse gas, into the atmosphere. The captured methane is generally flared
or used for energy purposes.1 The U.S. Environmental Protection Agency (EPA) has identified
four sources of methane with the greatest potential for capture in the near term: landfills, coal
mines, agriculture, and oil and gas systems. The amount of methane captured from each will
depend on legislative developments, economics, technology, and outreach.
Methane (CH4) constituted approximately 8% of U.S. greenhouse gas emissions in 2007.2
Anthropogenic (human-related) sources of methane in the United States include enteric
fermentation,3 landfills, natural gas systems, coal mines, and manure management. Efforts to
reduce emissions of methane—the second-most important greenhouse gas after carbon dioxide
(CO2)—could play a significant role in climate change mitigation.
This report will discuss the policy options for addressing methane capture (and their
implications), legislative proposals for methane capture, domestic and international sources of
methane, opportunities and challenges for methane capture, and federal programs that support
methane capture.
Policy Options for Addressing Methane Capture
Congress may employ multiple strategies to encourage or require methane capture as part of
climate change legislation: market-based approaches, such as a cap-and-trade program or
emissions fees; carbon offsets or credits as a complementary design element of a market-based
approach; emission performance standards; and/or maintaining existing programs and incentives.4
Policymakers may consider using different strategies for different methane emission sources.
These strategies and related issues are discussed below.
Market-Based Emission Control Programs
One option for policymakers is to include methane emission sources as covered entities in a
market-based greenhouse gas (GHG) emission control program. Market-based mechanisms that
limit GHG emissions can be divided into two types: those that focus on quantity control (e.g., a
cap-and-trade program) and those that focus on price control (e.g., emissions fees, often called a
1 Flaring is the combustion of the gas without commercial purposes. Flaring produces carbon dioxide which is a less
potent greenhouse gas than methane.
2 Environmental Protection Agency, 2009 U.S. Greenhouse Gas Inventory Report, April 2009, http://www.epa.gov/
climatechange/emissions/usinventoryreport.html.
3 Enteric fermentation is the production and release of methane via eructation (burping) and flatulence as ruminant
animals digest their feed.
4 The climate-changing impact of multiple greenhouse gases is commonly measured and compared using their global
warming potential as expressed in units of carbon dioxide equivalent. Therefore, many concepts and actions are
preceded with the word carbon which may actually account for an assortment of greenhouse gases in both quantity and
quality (e.g., carbon tax, carbon offset).
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carbon tax). Although each approach has its own set of advantages and disadvantages,5 both
would place a price on methane emissions from covered sources. To the extent that they are able,
covered entities (those subject to the cap or fee) would likely pass the emissions price through to
consumers. For example, if solid waste landfills were subject to a cap or fee based on methane
emissions, the landfill operators would likely raise the price of waste disposal to account for the
new cost of emissions.
Recent cap-and-trade and carbon tax proposals6 have generally not applied to methane emissions
from the primary sources of such emissions. A main argument for excluding some of these groups
concerns the administrative costs of covering them under an emissions program. As Table 1
indicates, the number of methane emission sources is relatively large compared to their total
contribution to U.S. GHG emissions. This is particularly the case for methane emissions from the
agriculture sector.
Table 1. Selected Sources of U.S. Methane Emissions and Potential Number of
Entities Subject to Emission Control Program
Percentage of U.S.
Potential Applications
GHG Emissions
Methane Emission Source
(2006 data)
Entity
Number
CH4 from livestock (enteric fermentation)
1.8
Cattle operationsa 967,440
CH4 from landfills
1.8
Landfillsb 1,800
CH4 from natural gas systems
1.5
Natural gas processors
530
CH4 from coal mines
0.8
Active coal minesc 1,374
CH4 from manure management
0.6
Cattle operations;
967,440
Swine operationsd
65,640
Source: CRS analysis of data from USDA and EPA.
a. U.S. Department of Agriculture, Farms, Land in Farms, and Livestock Operations: 2007 Summary (2008).
b. EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2006 (April 2008), citing BioCycle, 15th
Annual BioCycle Nationwide Survey: The State of Garbage in America (2006).
c. Methane from underground mines, which accounts for about 61% of coal mine methane, is removed
through ventilation systems for safety reasons. These emissions would be easier to monitor under an
emission control program than aboveground coal mine methane emissions. Number of active coal mines
from Energy Information Administration (EIA), “Coal Production and Number of Mines by State and Mine
Type,” at http://www.eia.gov.
d. U.S. Department of Agriculture, Farms, Land in Farms, and Livestock Operations: 2007 Summary (2008). Other
animals—chickens, horses, and sheep—contribute approximately 10% of the total emissions from manure
(EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2006 (April 2008), table 6-6).
Although an even larger number of sources (e.g., industries, automobiles, buildings) generate CO2
emissions, the vast majority of CO2 emissions can be addressed by subjecting a relatively small
number of entities to an emissions cap. This opportunity exists for CO2 emissions, because
policymakers could apply the emissions cap upstream of the actual emissions, typically where the
5 See CRS Report R40242, Carbon Tax and Greenhouse Gas Control: Options and Considerations for Congress, by
Jonathan L. Ramseur and Larry Parker.
6 See CRS Report R40556, Market-Based Greenhouse Gas Control: Selected Proposals in the 111th Congress, by
Jonathan L. Ramseur, Larry Parker, and Brent D. Yacobucci.
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emission inputs are produced or enter the U.S. economy.7 Under this approach, policymakers
could address CO2 emissions from fossil fuel combustion and non-energy uses—in aggregate
82% of U.S. GHG emissions—by covering fewer than 2,500 entities.8 For most methane sources,
particularly in the agriculture sector, an analogous opportunity does not exist.
In addition, some of the source categories identified in Table 1 may be more amenable to
emissions coverage than others. For example, roughly 25% of the methane emissions from
natural gas systems comes from field production,9 which may be impractical to monitor and
measure accurately.10 The remaining 75% primarily involves accidental releases sometimes
referred to as fugitive emissions.11 Landfill methane may offer fewer challenges in terms of
measurement, but the largest landfills are already reducing methane emissions pursuant to landfill
gas reduction requirements established by the Clean Air Act (42 U.S.C. 7401 et seq.).12
Carbon Offsets
Policymakers could encourage methane capture activities by allowing methane abatement as an
eligible offset project or as an emission (or tax) credit in a GHG emission control program, such
as a cap-and–trade system or carbon tax. A carbon offset is a measurable reduction, avoidance, or
sequestration of GHG emissions from an emission source not covered by a cap-and-trade system.
Most of the recent cap-and-trade proposals have allowed offsets (under varying conditions) as a
compliance alternative.13
Offsets would likely make an emissions program more cost-effective by (1) providing an
incentive for non-regulated sources to generate emission reductions and (2) expanding emission
compliance opportunities for regulated entities. The main concern with offset projects is whether
or not they represent real emission reductions. For offsets to be real, a ton of CO2-equivalent
emissions reduced from an offset project should equate to a ton emitted from a capped source,
such as a smokestack or exhaust pipe, and would not have occurred without the regulatory
incentive. This objective presents challenges because some offset projects are difficult to
measure.
7 An upstream approach would apply the cap to fossil fuels when they enter the U.S. economy, either at the mine,
wellhead, or another practical “chokepoint” in the production chain. Imported fuels would be addressed at their point of
entry into the United States.
8 For more on these issues, see CRS Report R40242, Carbon Tax and Greenhouse Gas Control: Options and
Considerations for Congress, by Jonathan L. Ramseur and Larry Parker.
9 As described by EPA, “wells are used to withdraw raw gas from underground formations. Emissions arise from the
wells themselves, gathering pipelines, and well-site gas treatment facilities such as dehydrators and separators. Fugitive
emissions and emissions from pneumatic devices account for the majority of CH4 emissions. Flaring emissions account
for the majority of the non-combustion CO2 emissions.” EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks:
1990-2006 (April 2008).
10 See, e.g., Gilbert Metcalf and David Weisbach, The Design of a Carbon Tax (June 2008), Tufts University and the
University of Chicago.
11 EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2006 (April 2008).
12 Landfill gas New Source Performance Standards (NSPS) went into effect in 1996. See U.S. Environmental
Protection Agency, “Standards of Performance for New Stationary Sources and Guidelines for Control of Existing
Sources: Municipal Solid Waste Landfills,” 61 Federal Register 9914, March 12, 1996.
13 For more information pertaining to carbon offsets, see CRS Report RL34436, The Role of Offsets in a Greenhouse
Gas Emissions Cap-and-Trade Program: Potential Benefits and Concerns, by Jonathan L. Ramseur.
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However, some methane capture projects, such as those from landfills or coal mines, are
generally considered to be of higher quality (more credible) than other offset types. These
projects are relatively easy to measure and verify, and in many cases would likely not occur if not
for the financing provided by an offset market. Therefore, the challenge of proving
“additionality” is easier to overcome.14
The advantage some methane capture projects have over other GHG mitigation activities may
spur policymakers to control these methane releases directly (via some of the options discussed),
instead of encouraging abatement through an offset market. Moreover, allowing certain activities
as offsets, while imposing emission controls or caps on others, may raise issues of fairness. For
example, why should specific GHG emission sources, such as electricity generators, be capped
while other sources, such as landfill or animal feedlot methane, have the potential to generate
financial gain for owners and/or operators through the offset market?
Emission Performance Standards
Another option for policymakers is to require emission performance standards for particular
methane emission sources. This approach has historically represented the core of U.S. federal air
pollution policy. New legislation would not be required to pursue the standards approach. The
ability to limit methane emissions already exists under various Clean Air Act authorities that
Congress has enacted, a point underlined by the Supreme Court in an April 2007 decision,
Massachusetts v. EPA. Although the current EPA Administrator has stated a preference for
controlling GHG emissions through new legislation, the agency has begun to take actions that
could lead to GHG emission performance standards from particular sources.15
Pursuant to Clean Air Act authority, EPA would achieve emission reductions by setting emission
performance standards on each source of pollution, or requiring that sources use a particular type
of technology, such as the “best available control technology.” Although emission performance
standards have proven to be effective through decades of experience, source-by-source regulation
often cannot achieve, by itself, a desired emission reduction target at the least collective cost.
Moreover, performance standards can be difficult to adjust as circumstances (e.g., technologies)
change. On the other hand, they may be less expensive where measurement, administrative, or
transaction costs are high relative to emission control costs. This approach may be a practical
option for certain specific sources of methane emissions.
Maintain Existing Programs/Incentives
As discussed later in this report, the federal government currently supports several programs that
stimulate methane capture. In addition to these initiatives, which are generally voluntary in
14 Additionality refers to whether the offset project represents an activity that is beyond what would have occurred
under a business-as-usual scenario. In other words, would the emission reductions or sequestration have happened
anyway? Additionality is generally considered to be the most significant factor that determines the integrity of the
offset.
15 For more information on these developments, see CRS Report R40585, Climate Change: Potential Regulation of
Stationary Greenhouse Gas Sources Under the Clean Air Act, by Larry Parker and James E. McCarthy; Environmental
Protection Agency, “EPA Finds Greenhouse Gases Pose Threat to Public Health, Welfare / Proposed Finding Comes in
Response to 2007 Supreme Court Ruling ,” press release, April 17, 2009, http://yosemite.epa.gov/opa/admpress.nsf/0/
0EF7DF675805295D8525759B00566924.
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nature, since 1996 the Clean Air Act has imposed air emission standards on large solid waste
landfills. However, as discussed below, the vast majority of landfills are not covered under the
Clean Air Act, and there is room to increase the amount of methane captured from solid waste
landfills. Moreover, the primary objective of these standards is to reduce the hazardous air
pollutants and non-methane organic compounds contained in landfill gas, not to reduce methane
emissions for climate-related reasons. Regardless, as mentioned above, the existing Clean Air Act
authorities could be used to address a wider universe of methane sources, for the express purpose
of controlling GHG emissions.
Because methane can be used as an energy source, the existing marketplace provides some
incentive to capture methane for this purpose. If a GHG emission control program were enacted,
such a program would increase this incentive by raising the price of traditional high-carbon
energy sources (e.g., coal) relative to captured methane. The strength of the incentive would
depend on the stringency of the enacted emission control program.
Legislative Proposals Concerning Methane Capture
Members of the 111th Congress have introduced more than 40 bills related to methane emissions.
One group of bills would specify methane as a greenhouse gas, promote biogas production,
support landfill gas recovery projects, and address or promote methane capture.16 Another set of
bills not related to methane capture would, among other provisions, for example, prohibit permit
issuance under the Clean Air Act for methane emissions from biological processes associated
with livestock operations, or expand methane hydrate research.17 Table 2 provides a summary of
selected legislation pertaining to methane capture and methane in general, and shows the range of
objectives addressed.
H.R. 2454, which passed the House on June 26, 2009,18 contains numerous energy provisions,
including a GHG emission cap-and-trade system. If enacted, the cap-and-trade program may
allow some methane capture activities to generate offsets. However, some methane sources may
be subject to emission performance standards. One enacted piece of legislation (P.L. 111-5, the
American Recovery and Reinvestment Act of 2009) extended and expanded existing incentives
for open-loop biomass and landfill gas electricity production and created a new incentive for the
same activities.
16 Biogas consists of 60%-70% methane, 30%-40% carbon dioxide, and trace amounts of other gases.
17 Methane hydrates—a mixture of water and natural gas—are a potentially huge global energy resource.
18 See CRS Report R40643, Greenhouse Gas Legislation: Summary and Analysis of H.R. 2454 as Passed by the House
of Representatives , coordinated by Mark Holt and Gene Whitney.
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Table 2. Selected Legislation Proposed in the 111th Congress Relevant to Methane
Bill (Short Title)
General Purpose
Comments
A. Bills to Capture Methane
H.R. 1158 (Biogas Production
To promote biogas production, and
The biogas must contain at least 52%
Incentive Act of 2009)
for other purposes.
methane.
H.R. 3202 (Water Protection and
To establish a Water Protection and
Considers the installation of small
Reinvestment Act of 2009)
Reinvestment Fund to support
renewable energy generators for
investments in clean water and
methane capture as an eligible activity
drinking water infrastructure, and for
for climate change adaptation and
other purposes.
mitigation grants.
H.R. 1342 (Landfill Greenhouse
To amend the Solid Waste Disposal
Allows for the collection of a fee on
Gas Reduction Act)
Act to provide for the reduction of
solid waste received by a solid waste
greenhouse gases, and for other
landfill and requires the local
purposes.
government to use the revenues
generated by such fees for entities to
undertake approved GHG reduction
projects within its jurisdiction (e.g.
landfill gas recovery projects).
H.R. 3534 (Consolidated Land,
To provide greater efficiencies,
Any coal lease issued on lands for
Energy, and Aquatic Resources
transparency, returns, and
which the United States owns both
Act of 2009)
accountability in the administration of
the coal and gas resources shal
Federal mineral and energy resources
include a requirement that the lessee
by consolidating administration of
recover the coal mine methane
various Federal energy minerals
associated with the leased coal
management and leasing programs
resources to the maximum feasible
into one entity to be known as the
extent, taking into account the
Office of Federal Energy and Minerals
economics of both the mining and
Leasing of the Department of the
methane capture operations.
Interior, and for other purposes.
H.R. 2454 (American Clean
The four titles of the legislation cover
Coal mine methane used to generate
Energy and Security Act of 2009)
clean energy, energy efficiency,
electricity at or near the mine mouth
reducing global warming pollution,
is considered a qualifying energy
transitioning to a clean energy
resource (e.g., source of usable
economy, and adaption to climate
energy).
change.
The carbon dioxide-equivalent of 1
ton of methane is 25 metric tons.
Sec. 732, “Establishment of an Offsets
Program,” may include greenhouse
gas reductions achieved through the
destruction of methane and its
conversion to carbon dioxide.
Under Title VIII, “Additional
Greenhouse Gas Standards,” the
Administrator shal include in the
inventory each source category that is
responsible for at least 10% of the
uncapped methane emissions in 2005.
The inventory required by this section
shal not include sources of enteric
fermentation.a
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Bill (Short Title)
General Purpose
Comments
B. Other Bills Concerning Methane
H.R. 1426
To amend the Clean Air Act to
No permit shall be issued under a
prohibit the issuance of permits under permit program under this title for
Title V of that act for certain
any carbon dioxide, nitrogen oxide,
emissions from agricultural
water vapor, or methane emissions
production.
resulting from biological processes
associated with livestock production.
H.R. 2996 (Department of the
Making appropriations for the
Section 420 of the Senate committee-
Interior, Environment, and Related Department of the Interior,
reported bill prohibited funds in the
Agencies Appropriations Act,
environment, and related agencies for
bill and other acts from being used to
2010)
the fiscal year ending September 30,
promulgate or implement any
2010, and for other purposes.
regulation requiring the issuance of
permits under Title V of the Clean Air
Act for carbon dioxide, nitrous oxide,
water vapor, or methane emissions
resulting from biological processes
associated with livestock production.
H.R. 3505 (American Energy
To increase the supply of American
Definition of Air Pol utant- Section
Production and Price Reduction
made energy, reduce energy costs to
302(g) of the Clean Air Act (42 U.S.C.
Act)
the American taxpayer, provide a
7602(g)) is amended by adding the
long-term energy framework to
following at the end thereof: `The
reduce dependence on foreign oil, tap
term `air pollutant’ shall not include
into American sources of energy, and
carbon dioxide, water vapor, methane,
reduce the size of the Federal deficit.
nitrous oxide, hydrofluorocarbons,
perfluorocarbons, or sulfur
hexafluoride.
S. 719 (Surface Estate Owner
To direct the Secretary of the Interior Lease may mean a lease that provides
Notification Act)
to notify surface estate owners in
for development of oil and gas
cases in which the leasing of federal
resources (including coalbed methane)
minerals underlying the land are to be
owned by the United States.
used for oil and gas development.
S. 1462 (American Clean Energy
To promote clean energy technology
Contains amendments to the Methane
Leadership Act of 2009)
development, enhanced energy
Hydrate Research and Development
efficiency, improved energy security,
Act of 2000 (P.L. 106-193).
and energy innovation and workforce
development, and for other purposes.
Source: Prepared by CRS.
a. Inventory refers to the annual tracking of greenhouse gas emissions and removals from various sources.
Methane: A Primer
Methane—a colorless, odorless gas with the molecular formula CH4—is produced by
“methanogenic” bacteria that decompose organic matter in the absence of oxygen. Sometimes
referred to as “marsh gas,” methane is flammable, can cause suffocation, and can be explosive in
low concentrations in air. It is the primary component (70%-90%) of natural gas fuel. Roughly
24% of total U.S. energy consumed in 2008 was natural gas. Consumption is spread across a wide
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array of economic sectors, with electric power generation and industrial consumption accounting
for 28% of total consumption; residential use, 21%; and commercial use, 13%.19
Global Warming Potential
Global warming potential (GWP) is an estimate of how much a greenhouse gas affects climate
change over a quantity of time relative to CO2, which has a GWP value of 1. Methane is a potent
greenhouse gas with a global warming potential of 25.20 Over a 100-year timeframe, methane is
25 times more effective than CO2 at trapping heat in the atmosphere. In other words, it takes 25
tons of CO to equal the effect of 1 ton of CH
2
4. Methane has a relatively short atmospheric
lifetime (approximately 12 years) when compared to the atmospheric lifetime of carbon dioxide;
thus efforts to capture methane from anthropogenic sources provide more near-term climate
change abatement than capturing or reducing comparable amounts of CO , but less multi-decadal
2
abatement.
Once methane or other greenhouse gases are converted, using GWP or other methods, they can be
expressed in a common unit of measurement: carbon dioxide-equivalent (CO2-eq. or CO2e). CO2e
both takes into account the potency of each gas and expresses the quantity of the gas. Carbon
dioxide-equivalent has been adopted as a principal unit of measurement to aggregate or make
comparisons across greenhouse gases. CO2e expresses the tons of a greenhouse gas in the
equivalent effect of tons of CO2 on climate change (more specifically, on “radiative forcing”).21
Once all gases are converted to CO2e, they can be compared or added together.
Sources of Methane
Domestic
The top three anthropogenic sources of the roughly 585 million metric tons CO2e of methane
emitted in 2007 were enteric fermentation, landfills, and natural gas systems.22 These three
sources combined were responsible for about 64% of total U.S. methane emissions (see Figure
1). There are also natural sources of methane emissions, such as wetlands, and releases of natural
gas from geologic formations. Natural sources of methane are generally assumed to account for
30% of an annual methane emissions inventory that includes natural and anthropogenic sources. 23
19 For more information on market conditions for natural gas, see CRS Report R40487, Natural Gas Markets: An
Overview of 2008, by Robert Pirog; and the Energy Information Administration report Natural Gas Year-In-Review
2008, April 2009, http://www.eia.doe.gov/pub/oil_gas/natural_gas/feature_articles/2009/ngyir2008/
ngyir2008.html#consumption.
20 The Intergovernmental Panel on Climate Change (IPCC) assigns methane a carbon dioxide equivalent, or global
warming potential, of 25. Intergovernmental Panel on Climate Change, Climate Change 2007: The Physical Science
Basis (2007), p. 212.
21 “Radiative forcing” is defined as the change in the difference between incoming and outgoing radiation at the top of
the troposphere. CO2e is not exactly equivalent to radiative forcing, but it is similar and easier to understand for policy
purposes than the main alternative, watts per square meter (W/m2).
22 1 teragram = 1 million metric tons. A Tg CO2e (teragram of carbon dioxide equivalent) is a principal unit of
measurement across greenhouse gases. See footnote 3 for the definition of enteric fermentation.
23 Kathleen Hogan, Current and Future Methane Emissions from Natural Sources, United States Environmental
Protection Agency, EPA 430-R-93-011, Washington , DC, August 1993.
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Figure 1. 2007 U.S. Sources of Anthropogenic Methane Emissions
Source: U.S. EPA.
Note: The “forest land remaining forest land” category contains forest land that stays forest land based on IPCC
guidance for defining inventory categories. Methane emissions from the category “forest land remaining forest
land” are attributed to wildfires and prescribed fires on managed forest land.
International
Methane accounted for nearly 17% of global greenhouse gas emissions in 2005.24 Asia is reported
as having emitted the most methane on a regional basis. China, India, the United States, the
European Union, and Brazil are the top five methane-emitting countries (see Table 3). The
agriculture sector is the leading source of methane emissions for the world (see Appendix).25
One analysis of global average atmospheric concentrations for methane indicates that, while
growth leveled off for approximately a 15-year period beginning in the early 1990s, methane
concentrations may have begun to increase again in 2007, possibly due to warmer temperatures in
24 World Resources Institute, Climate Analysis Indicators Tool (CAIT) Version 6.0., Washington, DC, 2009. Data
quality for the global methane emission estimates reported varies due to uncertainty and possible inconsistency
depending on reporting agencies adherence to data collection and interpretation for standardized definitions and
measurements for each sector and territory.
25 The World Resources Institute includes methane emissions from the following activities for the agriculture sector:
enteric fermentation from livestock, livestock manure management, rice cultivation, and other agricultural sources. The
sole exception, according to CAIT data compiled for 2005, is the United States, where the leading sources of
methane—the fugitive emission sector and the waste sector (e.g., landfills, wastewater treatment)—surpass the
agriculture sector slightly. However, 2007 data from EPA shown in Figure 1 depicts the agriculture sector as the
largest U.S. methane emission source. The World Resources Institute includes methane emissions from the following
activities for the fugitive emission sector: oil and natural gas systems, and coal mining.
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the Arctic and increased precipitation in the tropics.26 Global methane emissions from natural
sources are estimated at approximately 225 million metric tons of methane per year.27
Table 3. Top Five Methane-Emitting Countries in 2005
Country
Million MT (Tg) CO2e
% of World Total
China 853
13
India 548
9
United States
521
8
European Union
449
7
Brazil 389
6
Source: Climate Analysis Indicators Tool (CAIT) Version 6.0 (Washington, DC: World Resources Institute,
2009).
Notes: Excludes land use change.
Methane Use and Storage
Methane may be captured in its pure form or as a component of biogas, depending on the
source.28 The methane captured can be “flared” (combusted without commercial purpose) or used
to generate heat or electricity. Flaring the gas destroys the methane and yields carbon dioxide
(CO ) and water.29 The release of carbon dioxide as a result of flaring is less risky in terms of
2
climate forcing than releasing the methane or biogas as is into the atmosphere.
Captured methane is stored chiefly underground as a constituent of natural gas. Underground
storage options include depleted gas or oil fields, aquifers, or salt cavern formations30 (see Figure
2). A less common option is the storage of natural gas in liquid form. Liquefied natural gas (LNG)
is roughly one six-hundredth the volume of gaseous natural gas, allowing for transport by ship to
areas that are inaccessible via a natural gas pipeline.31
26 For more information, see CRS Report RL34266, Climate Change: Science Highlights, by Jane A. Leggett, and E.J.
Dlugokencky, L. Bruhwiler, and J.W.C. White, et al., “Observational Constraints on Recent Increases in the
Atmospheric CH4 Burden,” Geophysical Research Letters, August 18, 2009.
27 EPA prepared analysis using data from the Intergovernmental Panel on Climate Change, Climate Change 2007: The
Physical Science Basis Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental
Panel on Climate Change, 2007. http://epa.gov/methane/sources.html#natural
28 Biogas consists of 60%-70% methane, 30%-40% carbon dioxide, and trace amounts of other gases.
29 Stoichiometric equation for biogas combustion: CH4 + 2O2 → CO2 + 2H2O.
30 For more information on underground storage options, see http://www.naturalgas.org/naturalgas/storage.asp.
31 Energy Information Administration, Department of Energy, The Global Liquefied Natural Gas Market: Status &
Outlook, DOE/EIA-0637, December 2003.
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Figure 2. U.S. Underground Natural Gas Storage Facilities, Close of 2007
Source: Energy Information Administration, Office of Oil & Gas, Natural Gas Division, Gas Transportation
Information System, December 2008.
Notes: There are no natural gas storage facilities in Alaska or Hawaii.
Opportunities and Challenges for Methane Capture
Capturing methane from various sectors of the U.S. economy requires different strategies because
some strategies may be more economically feasible for specific emission sources or locations.
Policy laid out in forthcoming climate change proposals may further provide technical and
economic incentives to overcome barriers—past and present—to methane capture. The following
section summarizes opportunities and challenges for methane capture from the top four sources of
methane: agriculture, landfills, oil and natural gas systems, and coalbed methane (see Table 4).
Table 4. U.S. Methane Emissions by Source
(million metric tons CO2e)
Source 2000
2005
2006
2007
Agriculture—Enteric Fermentation
134.4
136.0
138.2
139.0
Landfills
122.3 127.8 130.4 132.9
Natural Gas Systems
130.8
106.3
104.8
104.7
Coal Mining
60.5
57.1
58.4
57.6
Agriculture—Manure Management
34.5
41.8
41.9
44.0
Source: U.S. EPA, U.S. Emissions Inventory 2009: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2007.
See http://epa.gov/climatechange/emissions/usinventoryreport.html.
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Agriculture
Methane emissions from the U.S. agriculture sector are mostly attributable to enteric fermentation
and manure management, the largest and fifth-largest sources of methane emissions in 2007,
respectively.32 Ruminant animals (e.g., cattle, sheep) are the major emitters of methane via enteric
fermentation, a non-point source of methane emissions. The amount of methane emitted from
enteric fermentation depends on the feed quality and amount of feed ingested by the animal.
Options to reduce methane emissions from enteric fermentation include improved animal
productivity and feed management.33
Some manure management systems (e.g., storage of liquid or slurry manure in a waste storage
structure) are a point-source of methane emissions. Methane released from the anaerobic
decomposition of manure depends mainly on the storage temperature, storage time, and manure
composition. Methane emissions from some manure management systems may be captured with
an anaerobic digestion system (AD system) that flares the gas or uses it for energy purposes.34
Barriers to methane capture from manure management include limited technology and
information exchange between agricultural producers and the technology transfer community,
high up-front capital costs for AD systems, unsatisfactory technology reliability, and low rates
paid by some utilities for the electricity generated.
Landfill Gas
Landfills were the second-largest U.S. source of methane emissions in 2007.35 Landfill gas—a
mixture of roughly 50% methane and 50% carbon dioxide, but including small amounts of other
gases—is released into the atmosphere if not captured. The amount of gas produced at any given
landfill depends on the amount of organic material in the waste, the landfill’s design, the climate
at the site of the landfill, and the operating practices used by the site’s operator. In general, large
amounts of organic waste and high levels of moisture in a landfill lead to greater gas production.
Landfill gas is captured at the nation’s largest landfills.36 A 1996 Clean Air Act regulation known
as the “Landfill Gas Rule” established New Source Performance Standards and Guidelines that
require landfills with a 2.5 million metric ton design capacity that accepted waste after November
8, 1987, to capture and burn the gas. The gas can either be flared or used for energy production—
often it is used as fuel for electricity generation. As mentioned above, flaring is less damaging to
the atmosphere than release of the methane.
32 In other parts of the world methane emissions from rice cultivation are a major concern because rice is grown on
flooded fields that produce anaerobic conditions to release methane. U.S. methane emissions from rice cultivation are
minimal because the United States is not a major producer of rice.
33 L. E. Chase, “Methane Emissions from Dairy Cattle,” Mitigating Air Emissions from Animal Feeding Operations
Conference, IA, May 2008, http://www.ag.iastate.edu/wastemgmt/Mitigation_Conference_proceedings/
CD_proceedings/Animal_Housing_Diet/Chase-Methane_Emissions.pdf.
34 For more information on anaerobic digestion systems, see CRS Report R40667, Anaerobic Digestion: Greenhouse
Gas Emission Reduction and Energy Generation, by Kelsi Bracmort.
35 Environmental Protection Agency, 2009 U.S. Greenhouse Gas Inventory Report, April 2009, http://www.epa.gov/
climatechange/emissions/usinventoryreport.html.
36 A common landfill gas capture system consist of an arrangement of vertical wells and horizontal collectors usually
installed after a landfill cell has been capped. Without a gas collection system, the landfill gas would escape into the
atmosphere.
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In promulgating the 1996 rule, EPA said that the 2.5 million metric ton minimum “corresponds to
cities greater than 100,000 people.” The agency also stated that the regulations “will only affect
less than 5 percent of all landfills” but would reduce emissions of methane by 37% at new
landfills, and by 39% at existing facilities.
In fact, partly as a result of tax incentives and voluntary programs, landfill gas capture projects
are in operation at approximately 480 landfill sites as of December 2008.37 This represents
roughly 27% of the 1,754 municipal solid waste landfills reported in operation in 2007.38
Whatever success existing regulations, tax incentives, and voluntary programs may be having, a
significant amount of methane continues to be emitted even at landfills subject to the Landfill Gas
Rule. In addition, there are few methane capture projects at smaller landfills and at landfills that
ceased operation before November 1987 (those not covered under the Clean Air Act). The latter
group, numbering in the tens of thousands of sites, poses a particular challenge. Often, there is no
responsible party who might implement a methane collection system if the site’s original owner is
no longer in business. At other sites (e.g., sites owned by local governments), there may be no
continuing stream of revenue to support installation and operation of the necessary equipment,
since the landfill has closed. Further barriers to additional landfill gas capture may include high
capital costs for equipment, low rates paid for the gas captured and/or electricity generated,
permitting requirements, and liability concerns.39
Oil and Natural Gas
Natural gas systems were the third-largest U.S. source of methane emissions in 2007. Methane
can be released from natural gas systems during normal operations, maintenance, and unexpected
system disorder. An array of technologies and suggested strategies to reduce methane emissions
from various stages of natural gas system production is available.40
Additionally, methane is emitted during oil production, transportation, and refining. Options to
reduce methane emissions from the oil sector include flaring, direct use, and reinjection of
methane into oil fields. Offshore oil operations (oil platforms) tend to use captured methane
directly because flaring is economically unattractive. Onshore oil operations usually inject the
captured methane into a pipeline. Captured methane can also be injected into an oil production
field to enhance future oil recovery. One analysis estimated the reduction efficiency (which is the
percentage reduction achieved with adoption of a mitigation option) for flaring, direct use, and
reinjection of methane to be 98%, 90%, and 95%, respectively.41 The equipment used for
37 Environmental Protection Agency, Landfill Methane Outreach Program , Energy Projects and Candidate Landfills,
http://www.epa.gov/lmop/proj/index.htm.
38 Environmental Protection Agency, Municipal Solid Waste in the United States: 2007 Facts and Figures,
http://www.epa.gov/epawaste/nonhaz/municipal/pubs/msw07-rpt.pdf. The most recent report contains 2007 data.
39 Lenders may hesitate to provide funding for landfill gas capture projects due to unease about possibly having to
remediate a landfill under CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act; 42
USC 9607).
40 Environmental Protection Agency, Natural Gas STAR Program: Cost-Effective Opportunities to Recover Methane,
http://www.epa.gov/gasstar/basic-information/index.html#sources.
41 Environmental Protection Agency, Global Mitigation of Non-CO2 Greenhouse Gases, EPA 430-R-06-005, June
2006.
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abatement has a technical lifetime of 15 years.42 Barriers to methane capture from oil and natural
gas systems include federal and state economic regulations, financial constraints, abatement
technology cost, and abatement technology availability.
Coalbed Methane
The coal mining sector was the fourth-largest source of U.S. methane emissions in 2007.43 Most
methane emissions from coal mining occur during the mining process in underground mining
operations. The amount of methane released depends chiefly on the coal mine type (e.g.,
underground mine, surface mine, abandoned mine) and the mining operation type. Two
techniques are available to capture methane emissions from coal mines: degasification (including
enhanced degasification) and ventilation air methane systems.
A degasification system facilitates the removal of methane gas from a mine by ventilation and/or
by drainage. Methane is captured through a series of vertical wells, horizontal boreholes, or gob
wells drilled into the mine before or after mining operations.44 A sizeable portion of the methane
captured from degasification systems can be injected into a pipeline directly for energy purposes.
Enhanced degasification uses the same approach as degasification systems, but has the capacity to
extract lower-quality methane that must be cleaned and upgraded to meet “pipeline quality” gas
criteria. Ventilation air methane (VAM) systems flush air into underground mines to keep
methane concentration levels at or below 1%. VAM systems are necessary to provide safe
working environments for miners because methane can be explosive in low concentrations in air.
Methane captured from degasification systems has a higher methane concentration (30%-90%)
than methane captured from ventilation air systems.
Methane captured from coal mines using the methods described above can be used to generate
electricity on-site or for sale to utility companies. Of the estimated 9,294 coal mines (active
underground, active surface, and abandoned underground) in the United States, about 580 are
currently active underground coal mines, of which 50 have methane capture projects.45 Barriers to
methane capture from coal mines include legal issues, economic circumstances (e.g., high capital
costs for equipment, low electricity prices), restricted pipeline capacity for transporting coalbed
methane from the mines to natural gas markets, and difficulties with technology development. A
primary barrier to methane recovery from coal mines is uncertainty regarding coalbed methane
ownership, which exists in part because coalbed methane is located in the same stratum as the
coal reserves, making a clear distinction for ownership difficult.46 Older leases may not clearly
specify whether the owner of the coal rights is also the owner of the coalbed methane. Ownership
may lie with the owner(s) of the coal rights, owner(s) of the oil and gas rights, or surface
owner(s). Ownership may also be an issue for federal lands in the West because developers of
42 Technical lifetime is the length of time the equipment is expected to perform as intended.
43 Environmental Protection Agency, 2009 U.S. Greenhouse Gas Inventory Report, April 2009, http://www.epa.gov/
climatechange/emissions/usinventoryreport.html.
44 A gob well allows for the extraction of methane from the gob area of a mine.
45 Environmental Protection Agency, Methane to Markets Partnership Country Specific Strategy for the United States,
October 2008, http://www.methanetomarkets.org/resources/coalmines/docs/coal_stratplan_us.pdf. Most of these coal
mines have been abandoned (8,000).
46 Environmental Protection Agency, Coalbed Methane Extra: Coal Mine Methane Ownership Issues, EPA-430-N-00-
004, 2007, http://www.epa.gov/cmop/docs/fall_2007.pdf.
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federally owned coalbed methane must apply for a gas lease to implement a coal mine methane
project via competitive leasing procedures open to all.
Concerns Applicable to All Sources
Two impediments to methane capture cross-cut the top four anthropogenic sources of methane
emissions: pipeline capacity, and the price offered by the electric power industry for electricity
generated by captured methane. In addition to capacity, another issue is pipeline access for those
wanting to purchase captured methane but not immediately adjacent to the methane capture
source. In addition to price, other electricity industry issues of concern are competitiveness and
the sale of excess power generated from captured methane.
Federal Support for Methane Capture
Periodic reports to Congress from the executive branch, as well as hearing testimony, have
conveyed the significance of methane capture since the early 1990s.47 Congress and the executive
branch have supported methane capture projects through voluntary programs, energy
management programs, and research and development programs. This section highlights existing
efforts.
Methane-to-Markets Partnership
The Methane-to-Markets Partnership is an international initiative for methane capture and reuse
from four sources: oil and gas, coal mines, landfills, and agriculture.48 The partnership is
administered by the U.S. Environmental Protection Agency (EPA), which supports the voluntary
efforts of the 29 country partners. National governments, research institutions, and the private
sector have collaborated since 2004 to develop cost-effective, near-term methane capture projects
globally. The partnership receives its legal authority from the Clean Air Act, Section 103 (42
U.S.C. § 7403), and the National Environmental Policy Act (NEPA, 42 U.S.C. §§ 4321-4347).
Approximately $4.5 million was appropriated to the partnership for FY2009. Supplemental
funding for the partnership is received from the U.S. Department of State. Other U.S. government
partners—the Department of Energy, the Department of Agriculture, the Agency for International
Development, and the Trade and Development Agency—have the discretion to provide funds to
support the partnership. Financial support from government partners varies in amount and by
fiscal year.
47 Environmental Protection Agency, Options for Reducing Methane Emissions Internationally, Volume 1:
Technological Options for Reducing Methane Emissions, EPA 430-R-93-006, July 1993; Environmental Protection
Agency, Opportunities to Reduce Methane Emissions in the United States Report to Congress, EPA 430-R-93-012,
October 1993. Nineteen hearings pertaining to methane have been held since 1990 including U.S. Congress, Senate
Committee on Environment and Public Works, hearing on S. 1772, Gas Petroleum Refiner Improvement and
Community Empowerment Act, 109th Cong., 1st sess., October 18, 2005, S.Hrg. 109-1001; and U.S. Congress, House
Committee on Science, Energy Research, Development, Demonstration, and Commercial Application Act of 2006,
109th Cong., 2nd sess., July 28, 2006, H.Rept. 109-611.
48 For more information on the Methane-to-Markets Partnership, visit http://www.methanetomarkets.org.
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Voluntary Methane Programs
EPA facilitates a number of voluntary programs related to the Methane-to-Markets initiative that
seek to reduce domestic methane emissions from different sectors. Many of these programs
receive broad legislative authority from the Clean Air Act, Section 103 (42 U.S.C. § 7403). EPA
provides some technical assistance and educational material. The AgSTAR Program supports
biogas capture and use at livestock operations managing liquid and slurry manures.49 The
Coalbed Methane Outreach Program (CMOP) works with the coalbed methane industry to reduce
coal mine methane emissions via methane capture and reuse.50 The Natural Gas STAR Program
specializes in promoting the reduction of methane emissions from the oil production and natural
gas sector.51 The Landfill Methane Outreach Program (LMOP) encourages landfill gas energy
projects.52 The Natural Gas STAR Program, Coalbed Methane Outreach Program, and the
Landfill Methane Outreach Program combined reduced methane emissions by approximately 64
million metric tons of CO2e in 2007 out of the roughly 324 million metric tons of CO2e of the
methane emissions reported for the landfills, natural gas systems, petroleum systems, and coal
mining categories.53
Federal Energy Management Program
The Department of Energy’s (DOE’s) Federal Energy Management Program (FEMP) addresses
energy management at federal facilities and DOE, as well as fleet and transportation
management.54 One component of the program is converting landfill gas to energy for use at
federal facilities. DOE has implemented three landfill gas recovery projects. FEMP receives its
legislative authority from the Energy Independence and Security Act of 2007 ( P.L. 110-140) and
was appropriated $22 million for FY2009.
Tax Incentives
Several federal tax incentives subsidize methane capture from landfill and agriculture sources.
These tax incentives are broadly broken down into three categories: (1) incentives to produce
electricity from captured methane gas; (2) incentives to build facilities that produce electricity
from captured methane gas; and (3) incentives to produce alternative fuels using captured
methane gas.
Two federal tax incentives subsidize the production of electricity from methane. The production
tax credit is allowed for the production of electricity from qualified energy resources at qualified
49 For more information on the AgSTAR Program, see http://www.epa.gov/agstar.
50 For more information on the Coalbed Methane Outreach Program, see http://www.epa.gov/cmop/index.html.
51 For more information on the Natural Gas STAR Program, see http://www.epa.gov/gasstar/index.html.
52 For more information on the Landfill Methane Outreach program, see http://www.epa.gov/lmop.
53 AgSTAR Program reduced methane emissions—not available. However, the program has provided technical
assistance for 135 operational anaerobic digestion systems, which generated approximately 332,100 megawatt-hours
(MWh) of energy in 2008. Environmental Protection Agency, ENERGY STAR and Other Climate Protection
Partnerships 2007 Annual Report, October 2008, http://www.epa.gov/appdstar/pdf/2007AnnualReportFinal.pdf; U.S.
EPA, U.S. Emissions Inventory 2009: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2007.
54 For more information on the Federal Energy Management Program, see http://www1.eere.energy.gov/femp.
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facilities, including open-loop biomass and municipal solid waste facilities.55 In general, open-
loop biomass and municipal solid waste facilities placed in service after August 8, 2005, and
before December 31, 2013, may claim a tax credit equal to 1 cent per kilowatt-hour of electricity
generated during the first 10 years of production.56 In addition, a one-time investment tax credit
equal to 30% of eligible investment costs is available, in lieu of the production tax credit, for
open-loop biomass and municipal solid waste facilities placed in service after December 31,
2008.57
Three tax-preferred bond finance options exist to help finance methane capture facilities used to
produce electricity. Qualified Energy Conservation Bonds (QECBs), Clean Renewable Energy
Bonds (CREBs), and New Clean Renewable Energy Bonds (New CREBs) are a type of bond
instrument, tax credit bonds, that offers the holder a federal tax credit instead of interest.58 The
rate of credit for CREBs is intended to be set such that the bonds need not be sold at a discount
(for a price less than the face value) or with interest costs to the issuer, while the credit rate for
QECBs and New CREBs is set for a credit rate of 70%. All three bond options are available to
finance qualified energy production projects, including open-loop biomass facilities and landfill
gas facilities. QECBs, CREBs, and New CREBs are all subject to national limits, $2.4 billion,
$1.2 billion, and $2.4 billion, respectively. CREBs and New CREBs are allocated by the
Secretary of the Treasury to eligible projects in inverse to their size, while QECBs are allocated to
the states based upon their share of total U.S. population. Issuing authority for QECBs is without
expiration, while CREB and New CREB authority expires at the end of 2009.
In addition, two tax incentives are available where methane gas is used to as a production input
for alternative fuels. Facilities with binding construction contracts in place before December 31,
2010, and placed in service before January 1, 2014, are eligible to expense one-half of the cost of
qualified property in the facilities first year of service.59 The remaining 50% of the cost is
depreciated under an accelerated five-year depreciation period. Further, compressed or liquefied
gas and liquid fuel derived from biomass is eligible for the 50 cent per gallon alternative fuel tax
credit for fuel produced through December 31, 2009.60
DOE Methane Hydrate Research and Development
Methane is not captured from naturally occurring gas hydrates because it is bound in the gas and
not released. However, recent attention has been directed toward the extraction of methane from
55 Internal Revenue Code (I.R.C.) Section 45. Municipal solid waste covers two types of power facilities: trash
combustion facilities that burn trash directly to generate power, and landfill gas facilities that first produce methane,
which is then burned to generate electricity. Anaerobic digestion systems are an example of an open-loop biomass
system.
56 The credit rate is adjusted each year for inflation. In addition, facilities placed in service prior to August 8, 2005, may
claim the credit for the first five years of production. Further, the date in service break-point for certain open-loop
biomass facilities is October 22, 2004.
57 I.R.C. Section 48.
58 Qualified Energy Conservation Bonds (QECBs), Clean Renewable Energy Bonds (CREBs) and New Clean
Renewable Energy Bonds (New CREBs) are defined in I.R.C. Sections 54D, 54C and 54, respectively. See CRS Report
R40523, Tax Credit Bonds: Overview and Analysis, by Steven Maguire, for more information on tax credit bonds.
59 I.R.C. Section 179C.
60 I.R.C. Section 45K.
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gas hydrates as a potential source of energy.61 The objective of the DOE methane hydrate research
and development program is to develop knowledge and technology to allow commercial
production of methane from gas hydrates by 2015. The DOE program completed a Gulf of
Mexico offshore expedition in May 2009 aimed at validating techniques for locating and
assessing commercially viable gas hydrate deposits.62 The program is planning a two-year Alaska
production test beginning in the summer of 2009 to provide critical information about methane
flow rates and sediment stability during gas hydrate dissociation. Both projects have international
and industry partners. Since the enactment of the Methane Hydrate Research and Development
Act of 2000 (P.L. 106-193), DOE has spent $87.3 million through FY2008, or approximately
78% of the $112.5 million authorized by law. The Omnibus Appropriations Act, 2009 (P.L. 111-
8), provided $20 million in FY2009 for natural gas technologies R&D, to include no less than $15
million for gas hydrates R&D. The Obama Administration has requested $25 million for the
program in FY2009, or 62.5% of the $40 million authorized by the Energy Policy Act of 2005
(P.L. 109-58). The gas hydrate R&D program is authorized through FY2010 under current law.
61 Methane hydrates—a mixture of water and natural gas—are a potentially huge global energy resource. For more
information on the DOE methane hydrate R&D program, see CRS Report RS22990, Gas Hydrates: Resource and
Hazard, by Peter Folger; and http://www.netl.doe.gov/technologies/oil-gas/FutureSupply/MethaneHydrates/rd-
program/rd-program.htm.
62 On May 6, 2009, DOE announced it had completed a 21-day drilling expedition in the Gulf of Mexico in
collaboration with the USGS and the Minerals Management Service. A preliminary announcement of the expedition
results is available at http://www.netl.doe.gov/technologies/oil-gas/FutureSupply/MethaneHydrates/2009GOMJIP/
GOMJIP_Leg2Announcement.html.
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Appendix. World Methane Emissions by Sector in
2005
Source: Climate Analysis Indicators Tool (CAIT) Version 6.0 (Washington, DC: World Resources Institute, 2009).
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Author Contact Information
Kelsi Bracmort
Peter Folger
Analyst in Agricultural Conservation and Natural
Specialist in Energy and Natural Resources Policy
Resources Policy
pfolger@crs.loc.gov, 7-1517
kbracmort@crs.loc.gov, 7-7283
Jonathan L. Ramseur
Donald J. Marples
Analyst in Environmental Policy
Specialist in Public Finance
jramseur@crs.loc.gov, 7-7919
dmarples@crs.loc.gov, 7-3739
James E. McCarthy
Specialist in Environmental Policy
jmccarthy@crs.loc.gov, 7-7225
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