Energy Supply: Energy Potential of Municipal Solid Waste Is Limited
(Letter Report, 09/20/94, GAO/RCED-94-200).
More than 195 million tons of municipal solid waste--basically household
and commercial garbage--were generated in the United States. Yet only a
small portion of solid waste is now used for energy production, mainly
through the use of electricity-generating facilities that burn municipal
waste as a fuel and engines fueled by waste gases from landfills. GAO
concludes that energy recovery from municipal solid waste holds limited
potential to contribute to the nation's overall energy production, not
only because of the volume and energy content of the waste itself, but
also because of factors affecting the use of waste disposal, including
public opposition and the availability of financing. This report also
discusses (1) the environmental impact of producing energy from waste,
(2) the Energy Department's research and development efforts to use
waste as a viable energy source, and (3) the potential energy savings
from and environmental impact of recycling waste material.
--------------------------- Indexing Terms -----------------------------
REPORTNUM: RCED-94-200
TITLE: Energy Supply: Energy Potential of Municipal Solid Waste Is
Limited
DATE: 09/20/94
SUBJECT: Alternative energy sources
Energy recovery from waste
Energy research
Solid waste management
Renewable energy sources
Waste treatment
Environmental impact statements
Recycling
Environmental research
Power generation
IDENTIFIER: DOE National Energy Strategy
**************************************************************************
* This file contains an ASCII representation of the text of a GAO *
* report. Delineations within the text indicating chapter titles, *
* headings, and bullets are preserved. Major divisions and subdivisions *
* of the text, such as Chapters, Sections, and Appendixes, are *
* identified by double and single lines. The numbers on the right end *
* of these lines indicate the position of each of the subsections in the *
* document outline. These numbers do NOT correspond with the page *
* numbers of the printed product. *
* *
* No attempt has been made to display graphic images, although figure *
* captions are reproduced. Tables are included, but may not resemble *
* those in the printed version. *
* *
* A printed copy of this report may be obtained from the GAO Document *
* Distribution Facility by calling (202) 512-6000, by faxing your *
* request to (301) 258-4066, or by writing to P.O. Box 6015, *
* Gaithersburg, MD 20884-6015. We are unable to accept electronic orders *
* for printed documents at this time. *
**************************************************************************
Cover
================================================================ COVER
Report to the Chairman, Subcommittee on Investigations and Oversight,
Committee on Science, Space, and Technology, House of Representatives
September 1994
ENERGY SUPPLY - ENERGY POTENTIAL
OF MUNICIPAL SOLID WASTE IS
LIMITED
GAO/RCED-94-200
Energy Supply
Abbreviations
=============================================================== ABBREV
Btu - British thermal unit
DOE - Department of Energy
EIA - Energy Information Administration
EPA - Environmental Protection Agency
MW - megawatt(s)
OTA - Office of Technology Assessment
Letter
=============================================================== LETTER
B-257080
September 20, 1994
The Honorable James A. Hayes
Chairman, Subcommittee on Investigations
and Oversight
Committee on Science, Space, and Technology
House of Representatives
Dear Mr. Chairman:
Over 195 million tons of municipal solid waste--basically household
and commercial garbage--were generated in the United States in 1990.
However, only a small portion of solid waste is currently used for
energy production, mainly through the use of electricity-generating
facilities that burn municipal waste as a fuel (combustors) and
engines fueled by waste gases from landfills. In addition,
waste-recycling programs can save energy by reusing certain waste
materials to make products rather than using virgin materials.
Because of the magnitude of the amount of waste produced annually,
you asked us to report on (1) the potential for using waste to
produce energy; (2) the environmental impacts of producing energy
from waste; (3) the Department of Energy's (DOE) research and
development efforts to use waste as a viable energy source; and (4)
the potential energy savings from and environmental impacts of
recycling waste material.
RESULTS IN BRIEF
------------------------------------------------------------ Letter :1
Energy recovery from municipal solid waste has the potential for
making only a limited contribution to the nation's overall energy
production. Although the current contribution of waste-derived
energy production is less than one-half of 1 percent of the nation's
total energy supply, DOE has set a goal for energy from waste at 2
percent of the total supply by 2010. The industry's estimates show a
smaller role for waste as an energy source in the future. The energy
potential from waste is limited not only by the volume and energy
content of the waste itself, but also by the factors affecting the
use of waste disposal options, including public opposition and the
availability of financing.
Energy production from waste combustors and from landfill gases
generates pollutants, although these are reduced through current
regulations that require the use of emissions control technology and
define operational criteria for the facilities. Regulations to
reduce harmful pollutants from both combustors and landfills have
been adopted, and more stringent rules are being developed. In
addition, several efforts are under way to decrease the impacts of
landfill gases by encouraging the owners and operators of landfills
to use these gases for energy production. Because most waste
combustors and landfill-gas energy projects generate electricity,
emissions from these sources may be offset when combustors or
landfill-gas projects replace electricity sources that produce even
more pollution, such as coal-fired utility plants.
DOE's research and development involving waste includes improving the
operational performance of combustors and refining the techniques and
technology for increasing energy production at waste landfills.
Other research initiatives include increasing the use of waste
materials as a resource for recycling and developing a clearinghouse
for information related to waste-derived energy production.
Although DOE estimates that one-third of the energy available from
waste is available in the form of energy savings through the
recycling of materials, the Department's research in this area is
ongoing. Energy savings from recycling some materials, such as
aluminum, have been demonstrated; for other materials, such as
certain grades of paper, more research is needed. Estimates on the
environmental impacts of recycling programs vary and depend largely
on the scope and assumptions of the analysis. DOE and the
Environmental Protection Agency (EPA) have cofunded research
activities designed to quantify the potential energy savings and
environmental impacts associated with waste management options,
including recycling programs.
BACKGROUND
------------------------------------------------------------ Letter :2
Municipal solid wastes are those generated at residences, commercial
establishments such as retail stores and restaurants, and
institutions such as hospitals and schools. These wastes are a
mixture of paper, wood, yard waste, food waste, plastics, glass,
rubber, and metals. According to EPA's estimates, the generation of
solid waste is expected to increase from the more than 195 million
tons generated in 1990 to 222 million tons by 2000. The predominant
disposal methods include using landfills, combustion, and
recycling/composting. Of the total waste generated in 1990, using
landfills, the most common disposal method, accounted for roughly 66
percent, while combustion accounted for about 17 percent, recycling
for about 15 percent, and composting for about 2 percent.
The largest source of energy production using waste as a fuel comes
from electricity-generating combustion facilities--roughly 125
combustors are currently in operation. The combustion of waste at
most facilities occurs by feeding waste directly into a furnace,
usually after sorting out noncombustible items and items to be
recycled. In other cases, the waste is sorted, processed, and
remanufactured into fuel pellets for later use. The majority of
waste combustors combust waste to generate electricity, but they also
generate steam for heating and other industrial purposes.
The remaining portion of waste-derived energy production stems
largely from burning methane emissions at landfills.\1 Landfill
emissions are formed through the decomposition of waste; the rate at
which they are released into the environment varies over time. The
emissions gradually increase as waste is added and may eventually
increase to the point at which energy production equipment can be
profitably used. Eventually the emissions decline, as do the
benefits of reducing them, and controls are no longer necessary.
Approximately 114 landfills with energy production systems are in
operation; about 75 percent of these projects generate electricity,
another 18 percent sell the gas for direct use (for example, as fuel
for boilers), and the remaining projects sell the methane to natural
gas pipeline companies for industrial uses.
Federal, state, and local laws govern the collection and disposal of
solid waste. At the federal level, regulations developed by EPA
under the authority of the Resource Conservation and Recovery Act of
1976, as amended, include criteria for the design, construction, and
operation of municipal solid waste landfills. In addition, the Clean
Air Act, as amended, requires the establishment of emissions
standards for combustors, and emissions standards have been proposed
for landfills that produce excessive emissions. State and local
governments are responsible for planning and implementing solid waste
programs.
--------------------
\1 The composition of landfill gas is typically 50 to 55 percent
methane, 45 to 50 percent carbon dioxide, and about 1 percent
nonmethane organic compounds.
ENERGY PRODUCTION POTENTIAL OF
WASTE IS LIMITED
------------------------------------------------------------ Letter :3
The potential of waste as a source of energy production is limited by
the volume of the waste generated, the energy content of the waste
stream, and the technology used to convert waste to usable forms of
energy.\2 DOE estimates that the majority of waste-derived energy is
likely to be produced through the combustion of (1) solid waste and
(2) the methane that is generated at landfills. This energy is
expected to contribute less than 2 percent of the nation's overall
energy production. The use of waste for energy production is also
limited by the extent to which energy disposal options are available
to solid waste managers. Many factors, including public opposition
and a lack of financing, can limit the use of energy-producing
disposal options.
--------------------
\2 The energy content of a fuel refers to its potential for creating
energy. A fuel with a high energy content, such as natural gas, is
capable of producing a large quantity of energy per unit of gas. A
fuel with a lower energy content, such as municipal solid waste,
produces a smaller quantity of energy per unit of waste.
ENERGY PRODUCTION FROM
COMBUSTORS WILL INCREASE
SLOWLY
---------------------------------------------------------- Letter :3.1
Although the increase in energy production from waste combustors is
expected to continue, the future rate of growth in the number of
these facilities is expected to be lower than in recent years. First
introduced in the 1970s, electricity-producing waste combustors now
have a total installed capacity of roughly 2,500 megawatts (MW).\3
The majority of the roughly 125 existing electricity-generating
facilities were placed in service after 1980. However, according to
one industry estimate, the number of planned combustors dropped by
more than half between 1986 and 1993.\4 According to several
analyses, the decrease in the growth of these facilities is the
result of several factors, including general economic conditions,
environmental concerns, and public opposition to siting combustors.
An upcoming GAO report will discuss many of the issues affecting the
use of waste disposal options.
The estimates of future energy production from electricity-generating
combustors vary widely. The differences in the estimates are to some
extent explained by the different assumptions used, such as the
projected volume of waste generated and the energy content of the
waste being considered for energy production. DOE's goal for
electric power production from waste by 2010 ranges from 14,000 MW to
28,000 MW. These estimates, developed for use in DOE's 1991 National
Energy Strategy, represent 1.9 percent and 3.8 percent, respectively,
of the projected total electricity-generating capacity in 2010. The
Energy Information Administration's (EIA) estimates show much slower
growth in the use of waste as a fuel source: EIA estimates roughly
5,200 MW of production by 2010. EIA's annual estimates of the
production of waste-derived electricity have decreased by more than
half since 1992.
The significant decrease in EIA's estimates of waste-derived energy,
according to EIA officials, is accounted for by several factors.
These factors include increased recycling efforts, stricter
environmental controls, and the uncertainty of future regulatory
requirements. These officials explained that recycling efforts can
remove some waste products with a high energy content, such as
plastics and certain grades of paper, from the waste stream, thus
reducing the potential energy available for energy production.
Stricter environmental controls can increase the cost of some
disposal options (such as combustors), which could lead to the
selection of disposal options (such as landfills) with different
energy production potentials. The uncertainty of future regulatory
requirements could also lead to different disposal choices, some of
which could result in reduced energy production.
--------------------
\3 A megawatt is 1 million watts; a watt is the basic unit used to
measure electrical power. In 1992, the nation's total
electricity-generating capacity was roughly 690,000 MW.
\4 Eileen B. Berenyi and Robert N. Gould, 1993-94 Resource Recovery
Yearbook: Directory and Guide, Governmental Advisory Associates,
Inc. (New York: 1993).
EFFORTS UNDER WAY MAY
INCREASE ENERGY PRODUCTION
AT LANDFILLS
---------------------------------------------------------- Letter :3.2
Energy production from methane-burning landfills is constrained by
many factors, although efforts under way may help increase the
current level of production. The impact of these efforts on the
production of energy from landfill gases is difficult to quantify;
EPA's recent estimates range from 800 MW to 5,000 MW of additional
electricity-generating capacity. These efforts include an
EPA-proposed rule to capture and control landfill gases, expanded
research and development programs to increase the efficiency and
effectiveness of energy recovery projects at landfills, and an
outreach program intended to remove or lessen barriers to using
landfill gases for energy production. Other factors that may
increase landfill energy production include new landfill regulations
that would require monitoring of methane emissions and a recently
established program that would pay owners and operators of qualified
renewable energy facilities (including waste landfills) for the
production and sale of electric energy.
EPA's proposed rule would require landfills with excessive emissions
to capture and control methane emissions. Under the proposed rule,
owners and operators of affected landfills must either burn (flare)
their methane emissions or recover the gas for use in energy
production. EPA has estimated that roughly 600 of the nation's
approximately 6,000 active landfills would be required to capture and
control their methane emissions. About 114 landfills already convert
methane emissions to energy; the remaining landfills are faced with
significant barriers to using methane as an energy source.\5 These
barriers include the low price of competing fuels, limited and
unstable markets, and regulatory and technological constraints. EPA
estimates that the majority of these landfills will flare methane
rather than recover it for energy production. However, as described
below, several initiatives are under way that may increase the
conversion of landfill methane to energy production.
The administration, in October 1993, announced the Climate Change
Action Plan, which is a strategy to reduce the volume of gases
suspected of contributing to a warming of the earth's atmosphere (the
"greenhouse" effect).\6 The action plan includes an initiative to
increase energy production at landfills. Methane is the second
largest source of greenhouse gas, and landfills account for about
one-third of the nation's methane emissions. The landfill initiative
targets the completion of EPA's proposed rule requiring controlling
and capturing landfill gases, supports an expansion of DOE's research
program for technologies that recover landfill gases, and establishes
an outreach program to remove or reduce barriers to using landfill
gases for energy production.
The proposed expansion of DOE's research program is intended to
facilitate the design of landfills to enhance the generation and
recovery of methane as electricity, fuel, or pipeline gas. The
initiative includes efforts to sponsor new joint demonstration
projects with private companies. A joint state-federal coordination
program is proposed to assist in siting and issuing permits to
landfills that will use methane recovery technology. DOE has
estimated that more than 100 MW in additional electricity-generating
capacity may be installed as a result of this program.
The outreach program called for in the action plan would encourage
landfill operators to overcome barriers to installing energy
production technology at landfills. The outreach program is intended
to capture methane emissions at those landfills not covered under
EPA's proposed rules. The program includes a proposal for EPA to
conduct state and regional workshops and to initiate site visits to
discuss the opportunities for energy production at landfills. EPA
estimates that as much as 120 MW of additional electricity-generating
capacity may be installed as a result of these efforts.
Other ongoing efforts may also affect energy production from
landfills, although the amount of increased energy production as a
result of these efforts is uncertain. EPA's expanded regulations for
landfills, which became effective October 9, 1993, require owners and
operators of landfills to monitor methane emissions to ensure that
the concentration of methane gas generated does not exceed a
predetermined safety level. EPA expects that this monitoring
requirement may create an additional incentive for owners and
operators of landfills to install energy recovery technologies.
As part of the Energy Policy Act of 1992, DOE was directed to make
payments to the owners and operators of publicly owned facilities
that use renewable energy (including landfill-gas energy projects)
for the production and sale of electric energy. However, the
effectiveness of these payments may be limited. First, these
payments are subject to the availability of appropriations, which
could limit the number of potential participants. Second, under
DOE's proposed rule for these payments, landfill-gas energy projects
will receive funding only after all other payments are made to
priority projects that include wind, solar, geothermal, and biomass
energy technologies. DOE expects to issue a final rule for this
program by the end of 1994.
In a report addressing the issue of methane emissions, sent to
Congress in October 1993, EPA found that the profitability of
landfill-gas energy projects is sensitive to the price at which the
projects sell the electricity they generate.\7 EPA's analysis found
that relatively modest increases in the price of electricity may
result in large increases in the number of landfill-gas energy
projects that could be expected to operate at a profit. EPA
estimated that, depending on electricity prices, anywhere from 60 to
1,400 landfills could profitably recover methane and that the
electricity-generating capacity added would range from 800 MW to
5,000 MW. However, the report noted the uncertainty in estimating
the costs of collecting landfill gas and producing electricity. In
addition, the report noted that the energy estimates did not consider
the existing barriers preventing the implementation of projects to
recover landfill energy.
--------------------
\5 The existing landfill-gas energy projects have a combined
electricity-generating capacity of roughly 350 MW.
\6 See also The Climate Change Action Plan: Technical Supplement,
U.S. Department of Energy, Office of Policy, Planning, and Program
Evaluation (DOE/PO-0011, Mar. 1994).
\7 Opportunities to Reduce Anthropogenic Methane Emissions in the
United States (EPA 430-R-93-012, Oct. 1993).
ENERGY PRODUCTION FROM WASTE
HAS ENVIRONMENTAL IMPACTS
------------------------------------------------------------ Letter :4
Energy production from waste combustors and from landfill gases
generates pollutants, although these are reduced through current
regulations that require the use of emissions control technology and
define operational criteria for the facilities. To further reduce
emissions from these disposal options, EPA is in the process of
issuing additional regulations to further reduce combustors'
emissions and issuing regulations to limit landfills' emissions into
the air.
EMISSIONS STANDARDS FOR
COMBUSTORS HAVE BEEN
EXPANDED
---------------------------------------------------------- Letter :4.1
A wide variety of materials is found in municipal waste streams, and
the environmental impact of energy production at combustors depends
in part on the composition of the materials being burned. The air
emissions standards developed by EPA have been designed to limit the
amounts of pollutants stemming from combustors. Currently, these
standards are being revised to regulate additional pollutants. The
ash residue remaining from the combustion process also contains
pollutants, and the potential environmental impacts of this residue
have been an ongoing source of concern for many years.
The air emissions from combustors consist of many pollutants,
including organic material, acid gases, and metal compounds.
Emissions of organic material include dioxins, some of which have
been found to be highly toxic: EPA has categorized one form of
dioxin as a probable human carcinogen. Acid gases include sulfur
dioxide and hydrogen chloride, each of which presents concerns
related to human health (respiratory problems) and the environment
(acid rain). Metallic compounds include those which EPA considers
possible human or animal carcinogens, such as arsenic, beryllium,
cadmium, and chromium. Other metals include mercury and lead, which
have been identified as threats to human health.
In 1991, EPA greatly expanded the emissions standards for both new
and existing combustors. One component of these standards is
technology-based, requiring facilities to rely on technology that
will reduce emissions. These standards also include requirements for
(1) operating practices that improve the combustion process and
thereby minimize pollutants and (2) certification for combustor
operators. Those facilities processing more than 250 tons of waste
per day are required to comply with these standards.
The Clean Air Act Amendments of 1990 broadened the emissions
standards for combustors to include emissions limits for several
pollutants, including cadmium, lead, and mercury. The amendments
also required that emissions standards be extended to include
facilities that process less than 250 tons per day. According to EPA
officials, emissions standards developed to comply with the
amendments should be proposed by the end of 1994.
The ash residue remaining from the combustion process continues to
pose environmental concerns. The issue of whether the ash generated
by combustors should be regulated as a hazardous waste was the
subject of a recent U.S. Supreme Court opinion.\8 The court noted
that the ash can be hazardous, even though the product from which it
is generated is not, because the contaminants in the ash residue are
more concentrated and more susceptible to leaching into groundwater.
The court held that the Resource Conservation and Recovery Act does
not exempt ash from regulation as a hazardous waste. As a result,
the ash will need to be tested to determine whether it is a hazardous
waste. To comply with the court's opinion, EPA has since announced a
strategy for testing the toxicity of the ash. Because of the higher
costs of hazardous waste disposal, the court's opinion could affect
the future of waste-derived energy production.
--------------------
\8 City of Chicago v. Environmental Defense Fund, 114 U.S. 1588
(1994).
ENERGY PRODUCTION AT
LANDFILLS CAN REDUCE METHANE
EMISSIONS
---------------------------------------------------------- Letter :4.2
Some landfills have adversely affected the environment, and some pose
future risks. The environmental impacts of landfills include
groundwater and surface water contamination and air pollution.
Regulations to reduce future environmental impacts have been adopted
recently, and regulations to reduce emissions of landfill gases are
to be made effective by the end of 1994. Energy production from
these facilities, however, because it uses waste methane gases from
landfills as a fuel source, can mitigate some of the environmental
effects.
Landfills are regulated to account for their many impacts on the
environment and human health and safety. In proposing landfill
regulations in 1988, EPA determined that many landfills have polluted
the air and the groundwater and surface water and that landfills will
continue to pose risks into the future. EPA also found that roughly
22 percent of the nation's abandoned hazardous waste sites on the
National Priorities List are municipal waste landfills.\9 EPA also
estimates that 70 percent of the existing landfills were operating
before 1980 (the effective year of EPA's hazardous waste rules);
these older landfills are of the most concern because they may have
received large volumes of hazardous waste.
Regulations to reduce the threat posed to the environment and human
health and safety were recently made effective, and additional
regulations to limit air emissions are being developed. EPA's
regulations on the design and operating criteria of landfills became
effective for most large landfills on October 9, 1993. These
regulations set forth minimum federal criteria for the location,
design, operation, groundwater monitoring, closure, and postclosure
care of landfills. EPA officials explained that although some older
landfills may close as a result of these regulations, many will be
replaced by new landfills that will operate under the new, more
stringent standards.
Producing energy from landfills' methane emissions can reduce the
environmental impacts of these sources. As discussed earlier, EPA is
also in the process of developing regulations intended to reduce air
emissions from landfills. According to EPA officials, these
regulations are scheduled to become effective by the end of 1994.
These regulations will require landfills with excessive gas emissions
to install equipment to collect methane gas and other emissions. EPA
estimates that under its proposed regulations, emissions of methane
will decrease roughly 18 percent more than would otherwise occur.
EPA also estimates that landfills' emissions from other organic
compounds will be reduced by 44 percent.
--------------------
\9 The priorities list specifies those hazardous waste sites posing
the most serious threats to public health and the environment and
requiring long-term cleanup activities.
DOE'S RESEARCH AND DEVELOPMENT
EFFORTS ENCOMPASS BROAD RANGE
OF ACTIVITIES
------------------------------------------------------------ Letter :5
DOE's research and development programs involving municipal solid
waste were funded at an average of roughly $3.5 million in each of
the last 3 fiscal years (1991-93). The research projects include
increasing energy production and minimizing the environmental effects
from combustors and landfills. Other research includes the
information transfer initiatives designed to increase the quality of
information available to officials responsible for managing solid
waste issues. Many of DOE's research projects are cofunded with EPA,
private businesses, and state and municipal governments.
DOE's research on combustors has focused on increasing energy
production, reducing environmental impacts, and determining proper
disposal techniques for ash from combustion. DOE recently completed
a study that determined the feasibility of combusting waste with
sewage sludge--two common municipal waste products--in a municipal
waste combustor. Other recently completed projects presented the
results of emissions control tests designed to reduce common
pollutants found in waste combustors. The ongoing research includes
identifying potential uses for ash from combustion, such as road
construction material. Other ongoing research includes determining
additional methods for reducing emissions at existing waste
combustors.
DOE's research on landfill gases has concentrated on increasing
methane production and energy recovery. DOE's ongoing research in
this area includes accelerating the rate of methane gas production
and reducing the cost of removing impurities from the gas. These
efforts are aimed at increasing energy production. Research projects
are expected to be established on the basis of the government's
sharing research costs with private industry. (App. I includes a
list of DOE's recently completed, ongoing, and planned waste-related
projects.)
As mentioned earlier, the administration's strategy to reduce
"greenhouse" gases includes research involving landfills' emissions.
The strategy proposes an outreach program to overcome barriers to
profitable methane recovery projects and thereby reduce methane
emissions. The strategy also proposes expanding DOE's ongoing
research activities to include a joint federal-state coordination
program to facilitate siting and issuing permits for landfill-gas
energy projects. The program would examine the environmental
performance standards and regulatory requirements identified as
barriers to using methane as a source of energy production.
DOE's other research and development efforts include information
transfer initiatives. DOE has found that information on waste
management is not always available to the public officials
responsible for making waste management decisions. As a result, DOE
has funded research intended to increase the quality and scope of
waste management information. The resulting reports have identified
factors affecting the cancellation of combustor facilities and
presented the status of available waste management alternatives.
ENERGY SAVINGS AND
ENVIRONMENTAL EFFECTS OF
RECYCLING PROGRAMS HAVE YET TO
BE CLEARLY DEMONSTRATED
------------------------------------------------------------ Letter :6
The energy savings available through the recycling and reuse of waste
materials depend on a comparison between the energy costs of using
reprocessed waste materials and the energy costs of
harvesting/extracting and processing virgin materials. Similarly,
determining the environmental effects of recycling waste materials
necessitates a comparison of the environmental consequences of using
reprocessed materials versus using virgin materials. DOE estimates
that significant energy savings and reduced environmental effects are
available through recycling programs. However, DOE plans additional
research in conjunction with EPA to further quantify the energy and
environmental impacts of waste management options, including
recycling programs.
ENERGY SAVINGS DEPEND ON
TYPE OF MATERIAL RECYCLED
---------------------------------------------------------- Letter :6.1
Estimates of the energy savings from recycling waste materials depend
on the waste materials being considered for recycling. For some
materials, such as aluminum, demonstrations have shown that making
products with recycled materials requires less energy than making
them with virgin materials. For other materials, such as certain
grades of paper, the energy savings through the use of recycled
materials rather than virgin materials have not been clearly
demonstrated. Many reports and studies on recycling issues are
consistent in suggesting the need for further analysis of energy
savings.
DOE has estimated that as much as one-third of the energy available
from waste is available in the form of energy savings from recycling
efforts.\10 DOE has reported that the amount of energy conserved
through recycling differs by the type of waste material. According
to DOE's estimates, recycling a pound of aluminum conserves 100,000
British thermal units (Btu), while recycling a pound of glass
conserves only 1,500 Btu.\11 DOE has also reported that the
conservation of energy in recycling a commodity may also differ
depending on the product produced. For example, recycling old
newsprint into new newsprint conserves roughly 5,000 Btu per pound,
while recycling old newsprint into tissue may require more energy
than using virgin materials.
In spite of previous estimates, DOE has continued to stress the need
for the additional quantification of energy savings. A 1992 DOE
report on the status of waste management alternatives identified as a
primary research area the analysis of using recycled materials versus
using virgin materials.\12 The report noted the wide variance between
published estimates of the energy savings achieved by recycling paper
products. The report also noted the need for additional research to
assess and compare the net energy savings associated with recycling
programs with the savings associated with other waste management
methods.
The Office of Technology Assessment (OTA), in a 1989 report on
municipal solid waste, found that the estimated energy savings from
using recycled materials versus using virgin materials varied by the
type of waste material.\13 OTA found that recycling several
materials, such as aluminum, glass, and plastics, resulted in
significant energy savings compared with using virgin materials. For
example, the recovery of aluminum from scrap has been found to save
90 to 95 percent of the energy required to produce the same product
from virgin materials. The energy savings occur largely because
using recycled aluminum avoids the smelting process, which accounts
for roughly 85 percent of the cost of producing new aluminum. In
contrast, OTA found that for some materials, such as paper products,
using recycled materials required more energy than using virgin
materials. For example, using recycled materials for manufacturing
box board required roughly 5,000 Btu per pound more than
manufacturing the same item using virgin materials.
Recognizing the need for a greater understanding of the economics of
waste management options, including recycling programs, DOE and EPA
have agreed to cofund research to examine the energy and
environmental impacts of the different disposal options. The study
will, among other things, seek to quantify the tonnage of recyclables
collected and recycled and the emissions associated with
remanufacturing goods from recycled materials as compared with the
tonnage and emissions associated with manufacturing goods from virgin
materials. The findings of this research are expected to lead to a
better understanding of the waste materials that should be recycled
and those that should be disposed of through other options.
--------------------
\10 Summary Costs and Benefits: Conversion of Municipal Solid Waste
to Energy (Draft), Department of Energy (Sept. 23, 1991).
\11 A British thermal unit is the standard unit for measuring heat
energy, such as the heat content of fuel. One Btu is the amount of
energy necessary to raise the temperature of 1 pound of water by 1
degree Fahrenheit.
\12 RD&D Priorities for Energy Production and Resource Conservation
From Municipal Solid Waste, National Renewable Energy Laboratory,
Department of Energy (NREL/TP-431-4982, Aug. 1992).
\13 Facing America's Trash: What Next for Municipal Solid Waste?,
Office of Technology Assessment (Oct. 1989).
ENVIRONMENTAL EFFECTS OF
RECYCLING ARE UNCERTAIN
---------------------------------------------------------- Letter :6.2
Similar to the estimated energy savings from using recycled materials
as compared with using virgin materials, the environmental effects of
recycling efforts are also uncertain. DOE has noted that to the
extent that raw material resources are saved, the environmental
impacts associated with the exploration, extraction, and primary
production of new materials are avoided. However, DOE has also noted
that making products from some recycled waste materials (such as
certain grades of paper) may produce greater quantities or more
concentrated forms of pollution than making products from virgin
materials.
A 1989 study by the New York State Energy Research and Development
Authority of the environmental impacts of waste disposal options
noted that information on the impacts of disposal options, including
recycling, is based on information that is often incomplete,
conflicting, and biased.\14 The report found that all waste disposal
options have associated pollution problems that can adversely affect
public health and the environment. The report concluded that waste
management decisions were being hindered by misperceptions of the
risks and benefits of the various waste disposal options. The report
recommended that more detailed information on the environmental
impacts of disposal options be developed and that comparative risk
assessments be conducted.
Similarly, a 1992 DOE report on the status of waste disposal options
noted a lack of technical data on the environmental impacts of
reformulating recycled materials into new products.\15 The report
noted that studies of the environmental advantages of recycling
individual waste materials appeared to have been based on limited
data and analysis. The report also noted that many of the advantages
claimed for recycling assumed high-effluent levels for virgin
manufacture that no longer reflect current actual practice. The
report identified as a primary research area the economic impacts of
using waste materials in the production process as compared with
using virgin materials. A 1992 report prepared by the National
Academy of Engineering concluded that in many cases the combined
economic and environmental benefits associated with recycling
programs remain to be demonstrated.\16 The report noted that in a few
instances, such as in recycling steel and aluminum, the environmental
and economic advantages are clear. The report also noted that the
scrap industry for these metals has been in existence for many years
and is a major reason for the development of cost-effective recycling
of these waste materials. However, the report further noted that the
benefits of recycling larger volumes of paper and plastic are less
obvious and depend on local factors, such as the existence of
secondary markets for these waste materials.
--------------------
\14 Joseph R. Visalli, The Similarity of Environmental Impacts From
All Methods of Managing Solid Wastes, New York State Energy Research
and Development Authority (Feb. 7, 1989).
\15 Data Summary of Municipal Solid Waste Management Alternatives:
Volume VII: Appendix E--Material Recovery/Material Recycling
Technologies, National Renewable Energy Laboratory, Department of
Energy (NREL/TP-431-4988G, Oct. 1992).
\16 Perspectives on the Municipal Solid Waste Problem, National
Academy of Engineering, Technology and Environment Program (July 8,
1992).
AGENCY COMMENTS
------------------------------------------------------------ Letter :7
We obtained written comments on a draft of this report from DOE and
EPA. In its comments, DOE stated that our assessment that municipal
solid waste is a limited resource and that its use is constrained by
many factors is correct. DOE provided editorial comments that have
been incorporated where appropriate. DOE's comments are included as
appendix II in this report.
EPA commented that the report is generally well written and
reasonably accurate in its description of EPA's activities. EPA also
commented that meeting 2 percent of the nation's needs using
municipal solid waste is significant. We agree, although as our
report points out, the 2-percent estimate is a goal set by DOE for
the year 2010. Our report notes that the current contribution of
waste as an energy source to overall energy production is less than
one-half of 1 percent.
EPA also commented that the report relies on estimates of energy
production from waste, especially for landfills, that are
conservative in light of efforts under way to promote this resource.
We continue to believe that we have examined all relevant estimates
of energy production from waste, including EPA reports, and that the
report adequately reflects this evidence. We revised the report, on
the basis of EPA's comments, to expand the description of efforts
under way that could enhance waste-derived energy production. These
efforts, we agree, could lead to increased energy production from
waste, but the estimates based on these efforts are preliminary and
must be judged in relation to the current constraints of using waste
as a fuel for energy production. EPA's comments and our responses
are included as appendix III in this report.
SCOPE AND METHODOLOGY
------------------------------------------------------------ Letter :8
To respond to your request, we interviewed and obtained documents
from DOE and EPA officials responsible for municipal solid waste
programs. We spoke to state and municipal officials located in
states that have made waste management decisions involving many of
the available waste disposal options. We discussed energy production
issues with officials at federal energy research laboratories,
including Argonne National Laboratory and Brookhaven National
Laboratory. We also interviewed officials responsible for research
and development on waste-related technology at DOE's National
Renewable Energy Laboratory. We conducted our review between
September 1992 and March 1994, in accordance with generally accepted
government auditing standards.
---------------------------------------------------------- Letter :8.1
Unless you publicly announce its contents earlier, we plan no further
distribution of this report until 30 days from the date of this
letter. At that time, we will send copies of this report to
congressional energy committees and other interested parties. We
will also make copies available to others on request.
Should you or your staff have any questions or need additional
information, please call me on (202) 512-3841. Major contributors to
this report are listed in appendix IV.
Sincerely yours,
Victor S. Rezendes
Director, Energy and
Science Issues
SUMMARY OF DOE'S MUNICIPAL WASTE
PROGRAM AS OF APRIL 1994
=========================================================== Appendix I
The goal of the Department of Energy's (DOE) Energy From Municipal
Waste Resource Management Program is to increase the use of waste as
a fuel or materials source and to ensure that environmentally and
economically sound waste management options are available for
decision makers. To achieve this goal, DOE has set several
objectives, which include providing credible information for decision
makers, improving waste combustion technology, increasing the
production of gas emissions at landfills, and increasing the use of
waste materials through recycling programs. The following is a list
of completed, ongoing, and proposed DOE waste-related research
efforts.
Table I.1
DOE's Research--Completed Contracts
Contr
act
numbe
r Project title Funding
----- ---------------------------------------------------------- -------------
ZF- Co-Combustion With Waste and Sewage Sludge $165,484
1-
1111
5-1
DA- Development of Mathematical Model of Municipal Waste 100,000
2- Combustion
1126
7-1
HZ- Technology Transfer Support 12,855
2-
1120
7-1
HZ- Research/Analysis/Support of Waste Management Programs 24,900
2-
1203
4-1
AAZ- Evaluation of Legislation, Regulations, and Rulemakings 288,356
4- Related to Waste Management
1408
7
HZ- Waste-to-Energy Technical Publications 38,000
2-
1127
1-1
XF- Assessment of Future Needs in Waste Utilization and 369,351
1- Disposal
1100
5-1
XD- Guide to Energy Production and Conservation From Waste 315,395
1-
1118
7-1
YZ- Evaluation of Waste Combustor Emissions Controls 258,348
2-
1125
3-1
ACA- Recycling Versus Solid Waste Combustion 13,674
3-
1217
3-1
HM- Planning/Coordination, New England Resource Recovery 8,000
1- Conference
1115
5-1
DA- Assessment of Factors Contributing to Abandonment of Waste 198,299
1- Combustors
1124
6-1
XF- Collection/Evaluation of Comparative Data for Waste 456,709
1- Management
1100
3-1
XF- Waste Management Program Technical Assistance 24,998
1-
1110
7-1
YN- Technical Assistance for Waste Management Program for 20,000
2- Fiscal Year 1992
1231
6-1
AS- Mercury and Dioxin Studies 80,000
2-
1209
8-1
================================================================================
Total $2,374,369
--------------------------------------------------------------------------------
Table I.2
DOE's Research--Active Contracts
Contr
act
numbe
r Project title Funding
----- ---------------------------------------------------------- -------------
AD- Assessment of Metal Wastage in Waste Steam Generators $100,000
2-
1114
3-1
AAL- Vitrification of Ash From Waste Combustion 7,000
3-
1305
0-1
XA- Landfill Gas Research 762,000
1-
1114
6-1
DA- Thermochemical Conversion Support 482,800
1-
1115
6-1
DA- Effects of Recycling 150,000
1-
1115
7-1
AAE- Municipal Solid Waste Study of Anaerobic Digestion 41,185
4- Facility
1345
5-1
CAK- Review of Anaerobic Digestion Activities 5,984
4-
1353
5-1
HZ- Research, Analysis, Support of Waste Management Programs 665,975
2-
1202
8-1
AAP- Solid Waste Assessment Models 275,598
4-
1414
3-
01
AAE- Waste-to-Energy Technical Publications 41,000
3-
1328
7-1
XAR- Utilization of Ash from Municipal Solid Waste Combustion 109,660
3-
1322
1-1
AR- Education Program 162,954
2-
1213
4-1
AAE- Education Program 85,788
4-
1414
8-
01
AAE- Utilization of Ash from Municipal Solid Waste Combustion 49,489
3-
1327
8-1
ACA- Recycling versus Combustion of Waste (Tasks 2 and 3) 25,329
3-
1334
9-1
AAE- Resource-Derived Fuel Commercialization Program and 47,350
4- Technology Transfer
1411
6-
01
YAR- Nitrogen Oxides Emission Control From Waste Combustion 45,392
3-
1318
4-1
YAE- Energy Efficiency of Waste Water Treatment Facility 30,122
3-
1348
0-1
CAE- Commercialization of Sludge/Waste Technology 26,840
3-
1327
6-1
AAV- Assessment of Sludge/Waste Technology 65,411
3-
1231
0-1
AR- Evaluation of Recycling Facilities 208,500
2-
1224
2-1
AAL- Evaluation of Integrated Waste Management Systems 300,000
3-
1318
5-1
AAT- Waste Information and Technical Assistance 59,820
3-
1344
5-1
AAE- Assessment of Wood-Related Wastes 65,000
4-
1407
7-
01
Landfill Gas Workshop and Transcripts 15,000
XAE- Utilization of Waste Incinerator Ash 100,079
3-
1324
5-1
TR- Demonstration of Emissions Control Techniques for Waste 374,062
1- Combustors
1129
3-1
================================================================================
Total $4,302,338
--------------------------------------------------------------------------------
Table I.3
DOE's Research--Proposed Contracts
Project title Funding
---------------------------------------------------------------------- --------
Assessment of Landfill Mining and Combustion of Recovered Wastes $10,000
Utilization of Waste Incinerator Ash 50,000
================================================================================
Total $60,000
--------------------------------------------------------------------------------
(See figure in printed edition.)Appendix II
COMMENTS FROM THE DEPARTMENT OF
ENERGY
=========================================================== Appendix I
GAO COMMENTS
--------------------------------------------------------- Appendix I:1
The following are GAO's comments on DOE's letter dated June 28, 1994.
1. DOE concurred with our general assessment that municipal solid
waste is a limited resource and that its use is limited by financial
considerations and public opposition. DOE also provided minor
editorial comments that have been incorporated where appropriate.
(See figure in printed edition.)Appendix III
COMMENTS FROM THE ENVIRONMENTAL
PROTECTION AGENCY
=========================================================== Appendix I
(See figure in printed edition.)
GAO COMMENTS
--------------------------------------------------------- Appendix I:2
The following are GAO's comments on EPA's letter dated August 11,
1994.
1. EPA holds the view that meeting 2 percent of the nation's energy
needs through the production of energy from waste is significant. We
agree. However, as our report points out, the current contribution
of waste as a fuel source to overall energy production is only
one-half of 1 percent. The 2-percent estimate cited by EPA, and also
by us in our report, is a goal set by DOE for the year 2010. We also
point out that other industry estimates show an even smaller role for
waste-derived energy production in the future.
2. EPA commented that we relied on "conservative" estimates of
waste-derived energy production and stated that our draft report
failed to recognize efforts under way to use waste as an energy
source. We have subsequently incorporated information that EPA
supplied to us which provides additional estimates of potential
energy generation from landfill gases. However, because of the
limitations as noted in these estimates, we continue to believe that
waste-derived energy production will make only a limited contribution
to meeting the nation's overall energy needs. We agree with EPA, as
our report suggests, that efforts under way to increase the
production of waste-derived energy could have a significant impact in
future years. We have expanded our discussion of these efforts on
the basis of EPA's comments.
3. EPA said that the manner in which we characterized municipal
waste combustors as compared to landfill-gas energy projects was
unclear. We agree with EPA that these two forms of energy production
vary significantly in terms of energy and environmental impact.
Waste combustors necessarily remove waste from the current waste
stream to produce steam and electricity. This technology inherently
generates pollutants, which must be reduced through both emissions
control technology and facility operating standards. Energy
production using landfill gases, on the other hand, presents a
somewhat different analysis. As EPA has pointed out, energy
production using landfill gases relies on emissions that would be
generated regardless of energy recovery efforts. This
characterization, we believe, is consistent with our report's
assessment that energy production using landfill gases can help to
reduce some harmful emissions that would otherwise occur. We have
revised our report to accommodate these comments.
4. We agree with EPA's comments that waste combustors have become
important waste disposal options in areas where landfill capacity is
constrained and that energy benefits can accrue from landfill-gas
energy projects and recycling programs. We also agree with EPA, as
we noted in our report, that energy savings from recycling varies by
the types of materials recycled and that in some cases, such as
aluminum, these savings can be significant. We have made appropriate
revisions to our report.
MAJOR CONTRIBUTORS TO THIS REPORT
========================================================== Appendix IV
RESOURCES, COMMUNITY, AND ECONOMIC
DEVELOPMENT DIVISION, WASHINGTON,
D.C.
Jim Wells, Associate Director
Gregg A. Fisher, Assistant Director
Daniel J. Feehan, Evaluator-in-Charge
Peg Reese, Senior Evaluator
Michael Shumaker, Staff Evaluator
OFFICE OF GENERAL COUNSEL
Jackie A. Goff, Senior Attorney