The methane-rich gas emitted from US landfills can potentially power hundreds of thousands of homes and businesses each year. As the US strives to strengthen its energy security and reduce its dependence on foreign oil, landfill gas is attracting increasing attention and investment. Initiatives on the state and federal levels are helping to fuel this rising trend.
by Brian Guzzone
October 17 2003 marked the 30th anniversary few Americans may recall - the 1973 Organization of the Petroleum Exporting Countries (OPEC) oil embargo. That fateful day signalled the beginning of a change in the way we view energy consumption. The OPEC oil embargo came at a time of declining domestic crude oil production, rising demand, and increasing imports. Thirty years later, energy prices paid by consumers and businesses are at an all-time high. At the time of writing, a barrel of oil was selling for over US$70. Energy pricing is subject to volatility and price swings, making reliable forecasting extremely difficult.
Notwithstanding the adverse impacts of the 1973 embargo, the US Department of Energy’s Energy Information Administration (EIA) reported total US energy consumption has increased by 25%. Given our reliance on petroleum and natural gas imports for the foreseeable future, are there domestic energy resources available today to lessen our dependence on fossil energy? The answer is a resounding ‘yes’. One positive outcome of the oil embargo is that renewable energy resources expanded significantly since 1973 and now account for over 7.5% of domestic energy use. Nationally, renewable power has been growing over 25% per year, and the EIA’s Annual Energy Outlook (AEO) forecasts renewable power demand will increase from 358 billion kWh in 2004 to 559 billion kWh in 2030.
As consumer and corporate demand for renewable energy increases, landfill gas energy (LFGE) is often overshadowed by renewables such as wind and solar. Most communities consider their local landfill more of a liability than a renewable energy asset. However, LFGE has the potential to reduce our dependence on fossil fuels, improve domestic energy security, and benefit the economy and the environment. Interestingly enough, one of the positive outcomes of the oil embargo was the first successful demonstration of LFGE, which became operational in California in the early 1970s. It was displayed by setting a tree on top of the landfill, which was then lit by electricity generated from a LFG-powered engine.
A number of developments and trends have emerged in the United States since those early LFGE projects in the 1970s, including increased interest in LFG from the corporate world, technology advancements in the industry, establishment of regulatory standards and financial incentives, as well as a growing interest in the international landfill gas energy marketplace under the Methane to Markets Partnership, to be discussed later.
Landfill gas generation
According to the US Environmental Protection Agency, in 2003 approximately 55% of all municipal solid waste (MSW) generated in the US (over 236 million tonnes) was disposed in over 2000 operational MSW landfills. Another several thousand additional landfills have closed since the early 1990s. As the organic fraction of the wastes in these landfills naturally decomposes, landfill gas (LFG) is produced. By volume, landfill gas is about 50% methane (CH4), the primary component of natural gas, and 50% carbon dioxide (CO2), in addition to small amounts of nitrogen, oxygen and hydrogen. Non-methane organic compounds, and trace amounts of inorganic compounds comprise less than 1% of the mix.
 LFG-fired reciprocating engine at the Roosevelt Regional Landfill, Roosevelt, Washington State |
Left uncontrolled, LFG can migrate to the atmosphere and contribute to odour problems, ground-level ozone and global climate change, and may cause health and safety concerns. On the other hand, instead of allowing LFG to escape into the air, it can be captured, converted, and used as an energy source. Landfill gas is typically extracted from landfills using a series of wells and a blower (or vacuum) system. This system directs the collected gas to a central point where it can be processed and treated depending upon the ultimate use for the gas. From this point, the gas can be simply flared or used to generate electricity or to replace fossil fuels in industrial and manufacturing operations.
MSW landfills are the largest source of human-caused methane emissions in the US, accounting for about 26% of these emissions. On a kilogram-for-kilogram basis, methane is a more potent greenhouse gas than carbon dioxide (about 23 times greater over a 100-year time frame). Methane is the second most important greenhouse gas (GHG), accounting for approximately 18% of total climate radiative forcing (a measure used to determine the extent to which the atmosphere is trapping heat due to emissions of greenhouse gases).
Methane is also a short-lived GHG with an atmospheric lifetime of 9-14 years. Methane’s short-lived nature represents a tremendous opportunity to mitigate GHG emissions in the near-term. LFGE is a viable and proven strategy to reduce GHG emission while producing useful energy.
Landfill gas in the US
US EPA’s Landfill Methane Outreach Program (LMOP) - a voluntary assistance programme that helps to reduce methane emissions from landfills by encouraging the recovery and use of landfill gas as an energy resource - has seen a dramatic increase in landfill gas energy projects over the past 10 years in the US. Since 1995, the number of LFGE projects has grown by over 180%. As of April 2006, there were 400 LFGE projects operating in 40 states, preventing emissions of over 8.4 billion m3 of LFG (or 4.2 billion m3 of methane per year). This is equivalent to powering over 725,000 homes and heating 1.2 million homes (see Figure 1). In addition, these 400 LFGE projects generated 9 billion kilowatt hours of electricity and 74 billion cubic feet (2.1 million m3) of landfill gas to direct-use applications. Moreover, they contributed to methane emissions reductions of 16.7 million metric tonnes carbon equivalent (MMTCE) or 61.2 MMTCO2E.
 Figure 1. Status of landfill gas energy project development and candidate landfills by state. Source: LMOP database, as of 18 April 2006 |
While these numbers are impressive, there is still significant opportunity for landfill gas energy development in the US. Currently the EPA estimates that there are over 600 landfills in the US that could economically support a project. Taken together, these 600 landfills would have a generation capacity of over 1400 MW (or enough electricity to power over 1 million homes across the country) or could supply 725 million cubic feet (20.5 million m3) per day or ~15,000 MMBTU/hour of gas to industrial and corporate end-users. If all projects were developed, the total expected additional annual environmental benefits would equate to removing the emissions from over 10.5 million vehicles on the road, or preventing the use of over 128 million barrels of oil.
Generating electricity from landfill gas
The generation of electricity from LFG makes up about two-thirds of the projects currently operational in the US. Figure 2 shows the breakdown of electricity-generating technologies.
 Figure 2. Distribution of electricity-generating technologies |
Electricity for on-site use or sale to the grid can be generated using a variety of different technologies, including internal combustion engines, turbines, microturbines, Stirling engines (external combustion engine), and organic Rankine-cycle engines. Over two-thirds of projects use internal combustion engines or turbines, with microturbine technology being used at smaller landfills and in other niche applications.
 A typical compressor station transmits landfill gas to an industrial end-user |
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Direct use of landfill gas
Directly using LFG to offset the use of another fuel (such as natural gas, coal and fuel oil) is occurring in about one-third (over 100) of the projects that are currently operational. This direct use of LFG - which means the gas is transmitted in a pipeline directly to an end-user - can be in a boiler, dryer, kiln, greenhouse, or other thermal applications. Figure 3 shows the breakdown of direct use technologies.
 Figure 3. Distribution of direct-use technologies |
Innovative direct uses include firing pottery and glass-blowing kilns; powering and heating greenhouses and an ice rink; and heating water for an aquaculture operation. Current industries using LFG include auto-manufacturing, chemical production, food-processing, the pharmaceutical industry, cement and brick manufacturing, wastewater treatment, consumer electronics and products, paper and steel production, and prisons and hospitals, to name just a few.
 Landfill gas is used to evaporate leachate at a landfil |
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Greening the environment
Reducing methane emissions has many important energy, safety, economic, and environmental benefits. First, because methane is both a potent greenhouse gas and has a short atmospheric lifetime, methane reductions can produce significant near-term results. In addition, methane is the primary constituent of natural gas. Producing energy from LFG can avoid the use of higher-emission traditional fossil-energy resources such as wood, coal or oil. Combusting LFG generates fewer air pollutants than burning an equivalent amount of energy in the form of coal or oil, which avoids the generation and release of sulphur dioxide (a major contributor to acid rain), nitrogen oxides (contributors to smog), toxic pollutants, and carbon dioxide. To illustrate this point, an example is a 3 MW landfill gas electricity project starting up at a landfill with previously uncontrolled landfill gas. The project would have a direct methane reduction of approximately 6000 tonnes per year (125,000 tonnes of carbon dioxide equivalents [CO2e] per year) and a fossil fuel displacement of approximately 700 tonnes of methane per year (15,000 tonnes of CO2e per year). The combined emissions reduction of 6700 tonnes of methane per year (140,000 tonnes of CO2e per year) would be equivalent to any of the following annual environmental benefits for 2005:
Market drivers for landfill gas
Corporate demand for reliable and inexpensive alternative fuels
In the past three years, the LMOP has seen a dramatic increase of interest in utilizing LFG for direct-use applications. The interest is fuelled by both economic and environmental factors. Energy costs in general have been rising and energy markets are becoming increasingly more volatile. At the time of writing, the Henry Hubb and NYMEX indicators showed the price of natural gas at just over $7 MMBTU, down from $13 MMBTU a few months before. These higher prices are encouraging energy users to look for less expensive sources. LFG can act as a long-term price and volatility hedge against fossil fuels, resulting in savings for a company. LFG supplied to a company is typically delivered at a firm price for 10 years or more, thereby ensuring energy pricing stability and a better bottom line.
In addition to providing a stable safeguard against natural gas price fluctuations, higher energy prices are also making LFG project economics more attractive. As a result, industrial operations and governments are turning to LFG to realize significant savings on their energy costs. BMW Manufacturing notes that it saves over $1 million per year at its South Carolina plant alone, where it is using landfill gas to generate electricity and capturing waste heat from the turbines. NASA, the first federal facility to use LFG, saves over $350,000 per year. Another transformation is that high energy prices are making longer-distance pipeline projects not only possible, but profitable. Five years ago, a pipeline project was generally thought to be economically feasible at 5 miles (8 km) or less. In 2003, however, BMW developed an LFG project that involved the construction of a 10-mile pipeline. In 2004, the Honeywell landfill gas project came on-line with a 23-mile (37 km) pipeline, the longest in the US.
Domestic climate opportunities
The economic benefits are certainly a powerful motivator, but environmental stewardship and corporate social responsibility are also strong market drivers for landfill gas projects. Corporations are joining voluntary programmes for GHG reductions such as EPA’s Climate Leaders programme and the Chicago Climate Exchange to translate their commitment to the environment. Climate Leaders is a voluntary EPA industry-government partnership that works with companies to develop long-term comprehensive climate change strategies. Companies joining Climate Leaders commit to a GHG reduction target. Several Climate Leaders including SC Johnson and General Motors have developed LFGE projects to help offset their GHG emissions footprint. The Chicago Climate Exchange® (CCX®) is a greenhouse gas emission reduction and trading pilot programme for emission sources and offset projects in the US, Canada, Mexico, and recent expansion into other international markets, such as the ones included in the European Climate Exchange. CCX members make a voluntary but legally binding commitment to reduce GHG emissions. By the end of Phase I (December 2006), all CCX members will have reduced direct emissions 4% below a baseline period of 1998-2001. Phase II, which extends the CCX reduction programme through 2010, will require all members to reduce GHG emissions 6% below baseline. Recently trading prices paid for GHG emissions have been at an all-time high, over $4.00/metric tonne of CO2.
A number of US states have also begun to implement GHG programmes to address climate change at the local level. In April 2006, California Climate Action Team, led by the California Environmental Protection Agency, released a report on how the state can meet California Governor Arnold Schwarzenegger’s goal of reducing GHG emissions by 30% by 2020. Capture of landfill methane emissions is one of the specific strategies outlined in the report. This report follows a March 2006 announcement by eight Northeastern and mid-Atlantic states of their commitment to the Regional Greenhouse Gas Initiative (RGGI), the first mandatory cap-and-trade programme to control CO2 emissions in the United States. Under RGGI, the states plan to cap CO2 emissions from power plants at 1990 levels beginning in 2009 and reduce emissions by another 10% by 2018.
Federal, state, and local incentives
Recent passage by the US Congress of the Energy Policy Act of 2005 (Act) will provide a boost to the development of LFG electricity projects. The Act provides a tax credit applicable to electricity generated from landfill gas. The Section 45 Production Tax Credit is worth 0.9 cents/kWh for electricity produced from landfill gas. To qualify, projects must be placed in service by 31 December 2007. The tax credit is expected to be a major driver of new LFG electricity projects. Over 40 LFG electricity projects are currently underway and expected to be operational by December 2007.
While landfill gas recovery offers significant environmental, energy and economic benefits to the public and private sector, there are still barriers to project development. In response, many states have developed innovative funding programmes and strategies that can help developers overcome financial barriers. These programmes and strategies include, among other things, loans, grants, renewable portfolio standards, renewable energy trust funds, and property, sales, and use tax exemptions.
One such state driver is the implementation of a renewable portfolio standard (RPS). An RPS is a state-level legislative requirement for utilities to generate or sell a certain percentage of their electricity from renewable energy sources. The percentage requirements under RPS programmes vary widely, but a majority of programmes classify LFG as a renewable resource. As of 1 March 2006, 22 states plus the District of Columbia have enacted a renewable portfolio standard (RPS) or a renewable portfolio goal (RPG), with all of these including LFG (see Figure 4). LFGE projects have benefited significantly from the RPS due to their cost-effectiveness and ease in bringing renewable electricity to customers.
 Figure 4. US states with renewable portfolio standards and goals that include landfill gas |
LMOP catalogues the various federal, state and local funding incentives in a guide entitled: ‘Funding Landfill Gas Projects: State, Federal, and Foundation Resources’, available at www.epa.gov/lmop.
Energizing international LFGE opportunities - Methane to Markets Partnership
Globally, landfills are the third-largest anthropogenic (human-influenced) source of methane emissions, accounting for about 13% or over 818 million metric tonnes of carbon dioxide equivalents. Figure 5 identifies some of the countries with significant methane emissions from landfills. Landfills also represent a tremendous opportunity to reduce methane emissions while generating a local source of energy for many thousands of communities
in countries around the globe.
In response, the Methane to Markets Partnership (M2M) - an international action-oriented voluntary initiative - was launched by the United States in 2004 with a goal to reduce global methane emissions to enhance economic growth, promote energy security, and improve the environment. The initiative focuses on cost-effective, near-term methane recovery for use as a clean energy source. Central to this effort is the establishment of partnerships among developed countries, developing countries and countries with economies in transition - along with strong participation from the private sector. Founding country partners include Argentina, Australia, Brazil, China, Colombia, India, Italy, Japan, Mexico, Nigeria, Russia, Ukraine, the UK and the US. In 2005, Canada, Ecuador and South Korea joined bringing the Partnership to 17 countries. These 17 countries represent more than 60% of global methane emissions.
The M2M targets four major methane emission sources: - landfills, underground coal mines, natural gas and oil systems, and agriculture (manure management). In the area of landfills, the initiative primarily centres on identifying disposal sites in developing countries and countries with economies in transition for methane capture and use projects. Additional efforts include the identification of barriers to project development, the improvement of enabling legal, regulatory and institutional conditions, and the creation of efficient energy markets.
Active involvement by private sector entities, financial institutions and other non-governmental organizations (NGOs) is considered essential to build capacity, transfer technology and promote private investment that will ensure the Partnership’s success. An example of leveraging the influence and outreach of a large international NGO was illustrated by the International Solid Waste Association (ISWA), at its 2005 Annual Congress in Buenos Aires, Argentina, with its commitment to the environment by joining M2M. ISWA, working with its membership, will play an integral role in identifying potential methane recovery and use projects for the Methane to Markets landfill sector.
One important issue for project development is that open dumps and unmanaged landfills are the predominant disposal options in many developing countries. These sites can be less-than-optimal candidates for LFG energy development due to small amounts of methane (resulting from aerobic degradation and rapid waste decomposition). However, many developing countries are currently transitioning to landfills from more uncontrolled systems. Landfills will provide a more environmentally sound disposal option for these countries, but they also will produce more methane. The M2M initiative can help facilitate a transition to landfilling by sharing information on effective landfill design and management, and how to integrate landfill methane capture and beneficial use into these planning processes.
As countries begin to implement laws, regulations and policies to improve solid waste management practices, promote alternative energy, and address greenhouse gas emissions, the economic viability of LFG energy projects will improve. Moreover, creating an atmosphere where potential investors (private sector, international development banks and financiers) are secure in the technical and policy framework that supports LFG energy projects will be essential to project development.
Brian Guzzone is Team Leader of the US EPA’s Landfill Methane Outreach Program. Before joining the EPA, Brian served as Technical Divisions Manager with the Solid Waste Association of North America.
e-mail: Guzzone.Brian@epamail.epa.gov
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The US EPA Landfill Methane Outreach Program
The US Environmental Protection Agency’s (EPA) Landfill Methane Outreach Program (LMOP) is a voluntary assistance and partnership programme that helps to reduce methane emissions from landfills by encouraging the recovery and use of landfill gas as an energy resource. The EPA launched LMOP to encourage productive use of this resource as part of the United States’ commitment to reduce greenhouse gas emissions under the United Nations Framework Convention on Climate Change.
LMOP forms partnerships with communities, landfill owners, utilities, power marketers, states, project developers, tribes and non-profit organizations to overcome barriers to project development by helping them assess project feasibility, find financing, and market the benefits of project development to the community. By preventing emissions of methane through the development of landfill gas energy projects, LMOP helps businesses, states and communities protect the environment and build a sustainable future.
LMOP provides information, software tools, marketing assistance, and access to technical experts to facilitate development of landfill gas energy projects. For more information about LMOP, please visit the LMOP website at www.epa.gov/lmop or call the LMOP hotline toll-free at 888 782 7937.
