Community Toolkit > Energy > Renewable Energy > Methane Recovery

Methane Recovery Pumps

Keene, NH

Community Profile: Keene is a medium sized town of about 22,500 residents located in the southwestern corner of New Hampshire, equidistant to Vermont and Massachusetts by 15 miles. Serving as the County Seat for Cheshire County, Keene has been a leader not only politically, but also environmentally, joining the Cities for Climate Protection Campaign (CCP) in April 2000 in an effort to lower energy consumption and related greenhouse gas emissions.

Project Outline:

• The project was initiated in 1994 by Keene Public Works Staff, including Duncan Watson. The City of Keene installed a landfill gas-to-energy generator at the Keene Municipal Landfill. The decision was made based on the cost savings of self-generated power versus utility supplied power as well as the environmental benefits of reduced air emissions.
• The 250 kW electrical generator, a Caterpillar G-3412-SINA, is powered by landfill gas initially through five interconnected wells and combusts more than 98% of the volatile constituents of the inlet gas. The landfill gas-to-energy generator also burns methane as its primary fuel. While the size of Keene’s landfill required only a passive gas venting system, the City of Keene installed an active gas collection system to reduce the effects of landfill gas.
• In 1999, Keene expanded the well field to seventeen interconnected wells and installed a transformer to supply single-phase power needs. The estimated gas collection rate is 372,600 standard cubic feet per day or 260 standard cubic feet per minute. The landfill gas composition by volume is approximately 58% methane, 35% carbon dioxide, 6% nitrogen, and 1% oxygen.
• Other communities with similar landfill gas-to-energy systems include Brattleboro, Vermont, Chicopee, Massachusetts, Saratoga Springs, New York.
• The landfill gas has an expected lifespan (when it ceases to be useful) up to the year 2014. The city of Keene is already investigating a replacement fuel for the transfer station. Keene is investigating the idea of a wind turbine. See the Hull Example.

Cost & Savings:

• The project was funded entirely by the City of Keene and cost approximately $280,000. The payback period was five years with continued annual electrical savings of approximately $55,000 beyond payback.
• The estimated CO2 savings are 140 tons per year.
• Currently, no state sponsored funding is available for New Hampshire or Vermont. In Maine, the Maine Technology Institute (MTI) is offering grants in the form of matching funds for up to 50 percent of project costs, not to exceed $50,000 per project. For more information or to see if your project would be eligible, check the MTI website or contact Betsy Biemann.
• Maine also offers a net-metering program through the Maine Utilities Commission. To learn more visit their website or contact Mitchell Tannenbaum.
• The Energy Policy Act of 2005 extended renewable energy production incentives to include landfill gas and provides federal incentives including provisions for renewed and expanded tax credits for landfill gas, bond financing, tax incentives, grants, loan guarantees. This document can be viewed in full text here or see the EPA’s Federal Funding Resource Guide.

Benefits:

• Lessons learned from the project include reduced greenhouse gas emissions, savings on electrical costs, and savings of tax payer dollars.

Process:

1. To initiate a landfill gas-to-energy system in your community, you must first determine if your landfill could support one. Generally, the larger the landfill the more gas it produces and the more economical the project would be. Some general guidelines to consider are:
   • Waste In Place (WIP): The desired amount of WIP is one million tons. This allows for the generation of approximately 300 cubic feet per minute of landfill gas which can generate 7,000,000 kWh per year. Small landfills of less than one million tons may be economical under special circumstances.
   • Landfill Characteristics: Desirably, the waste disposed is municipal solid waste only, the waste is at least 30 feet deep, and the landfill gas is approximately 50% methane.
   • Landfill Age: Peak methane generation occurs soon after landfill closure and those closed prior to 1993 have a lower probability of generating enough gas to make the project economically feasible.
2. An extensive resource guide put out by the Environmental Protection Agency’s (EPA)  Landfill Methane Outreach Program (LMOP) can be downloaded at no cost here. This step-by-step handbook describes the major aspects of Landfill gas-to-energy project development, including economic analysis, financing, choosing project partners, environmental permitting, and contracting for services.