Credit: courtesy Henry Obasi
Most people don’t think of a landfill as much more than a necessary evil at best, a community liability at worst. However, society’s current primary method of waste management produces a by-product with a significant energy value—landfill gas (LFG).
A landfill can provide a valuable, low-cost supply of energy. Corporations, utilities, and governments increasingly are recognizing LFG for its many benefits and are highlighting it in their sustainability reports.
LFG is the natural by-product of the decomposition of organic waste in landfills and is primarily made up of carbon dioxide and methane, the main component of natural gas. Instead of escaping into the air, LFG can be captured, converted, and used as an energy source. Using LFG has multiple benefits such as reducing odors and other hazards associated with LFG emissions, and preventing methane from migrating into the atmosphere and contributing to smog and global climate change. A potent greenhouse gas, methane is more than 20 times more powerful in warming the atmosphere than carbon dioxide, by weight.
LFG is extracted from landfills using a series of wells and a blower/flare (or vacuum) system. This system directs the collected gas to a central point where it can be processed and treated depending on its ultimate use. From this point, the gas can be simply flared or used to generate electricity through an internal combustion engine or turbine, just as natural gas would be; replace fossil fuels in industrial and manufacturing operations; fuel greenhouse operations, including heating the greenhouse and/or its water supply; or be upgraded to pipeline-quality natural gas.
Over the past 10 years, the Environmental Protection Agency’s (EPA) Landfill Methane Outreach Program (LMOP) has seen a dramatic increase in its number of projects. The program connects participants across five levels: industry partners (landfill owners, developers, consultants, and equipment suppliers); energy partners (power providers, marketers, and energy end users); state partners (state air and solid waste departments, energy and economic development offices, universities, as well as non-governmental organizations); community partners (local, county, and regional governments, and nonprofit organizations who develop and publicize LFG-use projects); and endorsers (nonprofit organizations with influence over land-use, waste management, or energy use decisions). There currently are 510 LMOP projects on line in the United States alone and more than 1,100 worldwide. The generation of electricity from LFG makes up about two-thirds of those 510 operational projects in the United States. Electricity for on-site use or sale to the grid can be generated using a variety of technologies, including internal combustion engines and turbines of various sizes, which utilize heat captured from burning the fuel to generate electricity. Using LFG to offset the use of another fossil fuel is occurring in about one-third of the operational projects. This direct use of LFG can be in a boiler, dryer, kiln, greenhouse, or other thermal applications.
However, there still is a long way to go. There are at least 500 landfills that economically could support a LFG conversion project. These landfills could produce more than 1,180 MW or could supply 200 billion cubic feet per year of gas to industrial end users.
In the past several years, LMOP has seen increasing interest in LFG, particularly for direct use. The interest is fueled by both economic and environmental factors. While recent energy costs have dropped, energy markets can be quite volatile, and industrial operations and governments are realizing significant savings by using LFG. BMW Manufacturing notes that it saves more than $1 million per year at its South Carolina plant alone, where LFG generates electricity and a combined heat/power system harnesses waste heat from the turbines for reuse in plant operations. NASA, the first federal facility to use LFG, saves more than $350,000 per year in the district heating systems at the Goddard Space Flight Center in Greenbelt, Md., by using LFG in place of natural gas.
The economic benefits are a powerful motivator for LFG projects, but environmental stewardship and corporate social responsibility are strong market drivers as well. Corporate citizens are joining voluntary programs for greenhouse gas (GHG) reductions such as the EPA’s Climate Leaders program and the Chicago Climate Exchange. Climate Leaders is a voluntary industry-government partnership where the EPA works with companies to develop long-term comprehensive climate change strategies. The Chicago Climate Exchange is a GHG emission reduction and trading program for emission sources and offset projects in the United States, Canada, and Mexico. Other corporations are looking at LFG projects as GHG reduction projects in the over-the-counter market, where transactions occur privately among the seller, buyers, and brokers involved in the transaction.
Large-scale companies including BMW, Mars, and Interface tout LFG projects as part of their sustainability efforts, and other corporate citizens are purchasing renewable energy credits from LFG projects. Through green power/energy initiatives, such as the EPA’s Green Power program, a company can buy and trade the renewable attribute of electricity generation from a renewable source, helping to meet renewable energy goals and offset the company’s fossil fuel use. Businesses including Staples, DuPont, and Pitney Bowes all have purchased RECs from LFG, and utilities such as Cinergy, Exelon, and We Energies are using LFG in their renewable energy portfolios.
For those interested in using LFG as an energy source, LMOP has a number of tools that can help determine if there is a landfill in their future. The program’s technical support includes finding a landfill, estimating gas generation/energy potential, and economic analysis of the project.
Using LFG for energy is a win-win opportunity. LFG energy projects involve citizens, nonprofit organizations, local governments, and industry in sustainable community planning and creative partnerships. These projects go hand in hand with commitments to cleaner air, renewable energy, economic development, improved public welfare, and greenhouse gas reductions.
Rachel Goldstein is the team leader of the U.S. Environmental Protection Agency’s Landfill Methane Outreach Program (LMOP). She can be reached at email@example.com.