Database of Landfill-Gas-to-Energy Projects in the United States
There has been a dramatic increase in the number of LFGTE projects in the US, and their environmental benefits are significant. Utilizing LFG displaces fossil fuels and reduces methane emissions.
There has been a dramatic increase in the number of landfill-gas-to-energy (LFGTE) projects in the United States. This is the result of a number of factors, including implementation of the Clean Air Act (CAA) regulations for MSW landfills, availability of economic incentives, and programs to help encourage greenhouse-gas (GHG) reductions and renewable energy. The US LFGTE industry has experienced about a 10% growth per year since 1990. As of January 1999, there were about 300 operational facilities, 90 facilities under construction, and 144 planned projects. The data presented in this paper are the result of a partnership between USEPA, the Solid Waste Association of North America (SWANA), and the US LFGTE industry. This paper discusses factors influencing the increase of LFGTE projects in the US and presents recent statistics from the database.
The environmental benefits of LFGTE are considered significant. Landfills are estimated to be the largest anthropogenic source of methane emissions in the US. Methane is a potent GHG that has 21 times the warming effect of carbon dioxide. Landfill gas is considered to be a threat to human health and the environment. Utilization of LFG displaces fossil fuel, creates jobs, and reduces emissions that impact human health and the environment associated with the use of nonrenewable energy sources such as coal (Thorneloe, 1992).
Landfill gas has a composition of about 50% methane and 50% carbon dioxide, with trace constituents of compounds that include volatile organic compounds (VOCs) and hazardous air pollutants (HAPs). Landfill gas has about half the heating value of natural gas. EPA promulgated CAA regulations for MSW landfills that were published March 12, 1996 (Federal Register, Vol. 61, No. 49). Although this regulation uses nonmethane organic compounds (NMOCs) as its trigger, it recognizes the potential cobenefits of reductions in GHGs, HAPs, and VOCs. The regulation requires that sites containing more than 2.5 million megagrams (Mg) and 2.5 million m3 or more of waste must collect and control LFG if their estimated emissions of NMOCs are 50 Mg or more per year. This will result in a reduction of around 6 million mt/yr. of carbon by the year 2000 (EPA, 1991). The associated GHG reduction is equivalent to around 8 billion lit. of gasoline per year or taking 4 million cars off the road (Federal Register, Vol. 61, No. 49). Data have also shown that leachate is typically less contaminated as a result of LFG control.
Factors Influencing the Increase in LFG Utilization
A number of factors influence LFG utilization. The CAA regulations promulgated in 1996 will result in more landfills being required to collect and control LFG. While most of the landfills will flare the gas to be in compliance with this regulation, it is expected that there will be an increase in the number of landfills that utilize LFG to help offset regulatory-compliance costs. The preamble of the promulgated regulation estimated that the approximately 45 new landfills estimated to be constructed over the next five years and about 300 existing sites will be required to install gas-extraction and -control systems. Additional rulemaking activities are underway that might require additional sites to collect and control LFG to respond to residual risk and urban air toxicity concerns. Also, many states have rules requiring LFG collection and control.
In addition to an increase in new projects as a result of CAA regulations, economic incentives have helped to encourage LFG utilization. The most significant of these has been a program providing federal tax credits (i.e., Section 29). Qualification for this program was discontinued in June 1998. Projects that qualified for tax credits have to complete implementation of the energy project in order to receive the tax credits. There has been a marked increase in new projects corresponding with the discontinuation of this incentive. The US LFGTE industry and others have attempted to get this program continued, but its future remains unclear. Many in the industry claim that LFGTE projects are marginally economical and that the tax incentives have been essential in helping to encourage new projects and keep existing projects operating.
Another important program is EPA’s Landfill Methane Outreach Program (LMOP) that was initiated as part of the Administration’s Climate Change Action Plan, which targeted landfill methane as a priority. LMOP was formed to help promote and facilitate LFGTE projects. It is working to minimize barriers impacting LFGTE and provide assistance to the US LFGTE industry in developing new projects. The Web site for further information on LMOP is http://www.erg.com/lmop1/about.htm.
Utility deregulation and its impact are unclear. Some states require a certain amount of renewable energy. This could have a positive benefit on the growth of new LFGTE projects and other types of renewable energy. However, renewable-based energy is not as cost-competitive as fossil-based energy because of the current low costs of fossil fuels in the US. Efforts to create a carbon tax have not been popular. Policy discussions are underway at the national and state levels to develop programs that will encourage the use of renewable energy and reduce GHG emissions.
Consolidation of the waste-disposal industry along with consulting and engineering services is also impacting the US LFGTE industry. Two of the largest waste management companies in the US, Waste Management Inc. and Browning-Ferris Industries Inc. (BFI), have undergone or are undergoing consolidation. Waste Management has 28 operating projects, with three under construction and seven planned. It has the largest number of projects of any developer and was an early pioneer in developing LFGTE projects. Since 1992, BFI has been aggressively developing projects. currently it has 19 operating projects, with three under construction and six planned. With increased emphasis on profit margins and cost-cutting measures being adopted, these consolidations may impact the expansion or continuation of existing projects and the development of new projects.
As a result of many factors influencing LFG utilization, the need exists for up-to-date, credible statistics. A goal for the development and maintenance of the database described in this paper is to help track industry trends. It will also help to better quantify the emission reductions occurring at US landfills and document pollution-prevention benefits. Efforts are also underway, as a result of funding by EPA’s LMOP, to collect data from sites that are flaring LFG. It is hoped that this information will help to identify potential new sites for LFGTE projects. In addition, the type of data collected for LFGTE projects is being expanded to include information on existing and state-of-the-art technologies, including leachate evaporators, fuel cells, and the operation of landfills as "biocells" or enhanced bioreactors, that can help improve the economics of LFG utilization (Thorneloe et al., 1998; Roe et al., 1998).
Database of US LFGTE Projects
For several years, through SWANA’s LFG database committee, information has been collected to help track industry trends. EPA has supported this effort through its Office of Research and Development and LMOP. This has been a voluntary effort, and there has been excellent cooperation by the US LFGTE industry. Using data collected in 1998, the LFGTE database is being updated and verified through contacts within the industry and site visits. The updated version is to be released soon.
Data have been collected on projects that are currently operating, are under construction, or are in advanced planning status. Tentative projects and those without signed contracts are excluded. The term project is defined as the number of different technologies in use at a site. For example, the largest LFGTE plant in the US, Puente Hills (CA), has four separate projects, including a boiler/steam turbine plant, a gas-fed turbine, a process for producing compressed LFG for providing vehicle fuel, and gas sales to a local college. As gas flow changes, many developers will use a modular approach and add equipment for increased power-generation capacity or remove equipment for use at another site. Expansions are considered one project unless different technologies are in use. Also, developers will occasionally collect gas from nearby sites to improve economies of scale. There are several cases in which two or more landfills fuel one project. This is counted as one project.
Using data collected in 1998 for the US LFGTE industry, we have found about 10%-per-year average growth, with a 16%-per-year average growth of new projects for this decade. Eighty-three new projects have begun operation since 1996, with 18 new facilities in the last year. currently there are about 300 operational projects, 90 projects under construction, and 144 planned projects. Figure 1 illustrates the growth for the US LFGTE industry. New LFGTE projects begun each year are provided in Figure 2.
Figure 1. Annual and Cumulative Growth for US LFGTE Projects
Figure 2. Cumulative Growth of New LFGTE Projects in the US
There has been a dramatic increase in the number of LFGTE projects in the US, with about 130 in 1990 and about 300 in 1999. This is the result of a number of factors, as previously discussed. California was the early leader in LFGTE because of a favorable utility Standard Offer No. 4 contract that offered high electric prices. Because of heavy response, this contract was offered only in 1984 and 1985. California was also one of the first states to require LFG collection and control. Similarly, in 1989, Michigan passed legislation providing incentives for renewable power that has resulted in the construction of many LFGTE facilities in that state. Michigan is fully subscribed, however, which has slowed additional development. Other states have also used incentives to encourage LFGTE, including Pennsylvania, New York, and New Jersey. The number of projects is expected to increase thanks to programs that help encourage renewable energy, GHG reductions, and the implementation of the CAA regulations. It is not expected to grow at the rate experienced in this decade, however, because many of the large projects that provide favorable economics have been developed. New landfills being planned are typically on larger sites, however, and will likely be required to collect and control LFG. Hopefully programs will exist that will encourage utilization of LFG so that increased benefits to human health and the environment can be realized.
Future Growth: Facilities in Construction and Advanced Planning
About 61 projects are in an advanced-planning status, and 90 projects are under construction. The majority of these projects are commercial projects taking advantage of the tax credits that can potentially offset regulatory-compliance costs. However, for these projects to go forward there must be favorable economics. It is unclear what the impact might be on these planned projects as a result of the recent consolidations occurring in the waste industry.
A developer must secure an energy contract that exceeds the developmental costs. The existence of favorable energy contracts in the early 1980s, over $0.08/kWh, caused many more LFGTE facilities to be developed in California than in any other state. Then California development slowed significantly in the early 1990s because the utilities were typically offering about $0.03/kWh and the Standard Offer No. 4 contracts began to phase out. Tax credits have helped to offset the lower value of the energy contracts.
Other states have bills to favor renewable energy. Illinois passed a bill that has resulted in at least 11 projects that are currently in construction or in advanced planning. Other states in the East are gaining momentum. Medium-heating-value projects are increasing in frequency, and the US has over a decade of experience using boilers. There are 28 planned medium-heating-value projects and 10 in advanced-planning status. Also, utilities have more interest in LFG utilization to help them meet GHG-reduction goals. currently, several utilities are using, or planning to use, LFG in large fossil-fueled plants and are helping to develop new projects, including the use of fuel-cell technology.
Types of Technologies Being Used in the US
Landfill gas can displace natural gas in essentially all applications and other fossil fuels in most applications (Augenstein and Pacey, 1992; Doorn et al., 1995). The distribution of technologies in use by the LFGTE industry is provided in Table 1. Over 70% of operational LFGTE projects generate electricity. Electrical-generation technologies include reciprocating engines, gas turbines, boiler/steam turbines, combined cycles (gas turbine and steam turbine), and fuel cells. Over 50% of the operating LFGTE projects use reciprocating engines. Innovations in their design have improved energy efficiency and reduced byproduct emissions.
Table 1. Distribution of Project Types in the US LFGTE Industry
Emerging technologies, such as fuel cells and leachate evaporators, are being more widely considered for future use. EPA’s Office of Research and Development conducted a review of emerging technologies for LFG. It provides a ranking of these technologies based on the degree of field demonstration (Roe et al., 1998). Fuel cells are considered to be a preferred technology for LFG utilization because of their higher energy efficiency compared to conventional technology and minimal environmental impact. A recent demonstration of the application of fuel-cell technology on LFG was conducted by EPA’s Office of Research and Development (Spiegel et al., 1997; 1999).
Leachate evaporators are also being used more widely. These processes use heat to evaporate leachate and combust the exhaust gas that contains VOCs and HAPs. There are different variations of this system. The unit manufactured by Organic Waste Technologies has two different designs that are described in a recent EPA report (Roe et al., 1998). Another company, Power Strategies, has a unit that exhausts the evaporated gas from the leachate evaporator to a reciprocating engine, where it is combusted while producing electricity. The waste heat from the engines is also utilized to evaporate the leachate.
US LFGTE Developers
currently, there is much more competition, and the potential profit is much less than a decade ago when 10%-20% royalties were often obtainable. Decreasing prices for electricity and natural gas have forced LFGTE developers to become more efficient, and many have eliminated royalties. US developers typically offer to install and operate the gas-collection system at cost. Depending on the size of the landfill, the landfill owner can save millions of dollars in avoiding the cost of installing, operating, and maintaining a landfill’s gas-collection system by contracting with an LFGTE developer. Small lease payments may be offered to large-landfill owners by the developers.
Numerous independent developers are actively contacting landfill owners to contract LFG rights and to develop LFGTE projects. LFGTE developers typically are specialists who focus on the utilization of LFG and its tax benefits as opposed to landfill owners who focus on refuse disposal and landfill operations.
Over 10 independent developers are looking for new projects to develop, which results in a competitive market. Owners of medium or large landfills issuing requests for proposals for the development of LFGTE facilities can generally expect several competitive proposals in response. An established community of competitive developers has grown with the LFGTE industry. LFGTE projects are quickly developed whenever economically feasible, given willing landfill owners.
The information provided for this database has been collected under a voluntary basis. The data presented in this paper are being updated and verified for release in an electronic version. Future updates and maintenance are also planned.
The database is also being expanded to provide data on Canadian projects to create a complete set of data for North America. Anyone interested in providing additional data or information is encouraged to contact SWANA (301/585-2898). The goal is to provide up-to-date and credible data to help track trends occurring as a result of LFG utilization.
Author's Bio: John Pacey is the founder of Emcon, an engineering consulting firm with offices throughout the US.
Author's Bio: Susan Thorneloe is a senior environmental engineer with EPA's Office of Research and Development/National Risk Management Research Laboratory/Air Pollution Prevention and Control Division, both in Research Triangle Park, NC.