Landfill Gas-to-Energy Project Awarded at Hill Air Force Base
April 20, 2004
A Super ESPC Delivery Order was awarded on September 30, 2003, under the FEMP Biomass and Alternative Methane Fuels (BAMF) program. The award was made by the Hill Air Force Base to Exelon Services Federal Group. The principal energy conservation measure (ECM) is use of landfill gas to generate electricity. The delivery order will bring $4.9M of private capital investment to the base resulting in $17M of energy cost savings over the 20 year period covered by the contract. This is the first delivery order awarded under the BAMF program.
Landfill gas is an alternative fuel source that is domestic, renewable, and can be less expensive to use than conventional fuels. It is the product of the natural decomposition of organic materials in landfills that results in formation of methane and carbon dioxide. These gases are waste products and are typically vented to the atmosphere or flared resulting in increased greenhouse gases. Landfill gas can instead become a long-term source of energy that can be used to generate electricity, steam or both in combined heat and power (CHP) applications. Hence, these energy products are generated with zero net increase in greenhouse gas emissions. In addition to the environmental benefits, the use of landfill gas for on-site power generation can decrease a facility�s vulnerability to grid interruptions.
The use of landfill gas involves proven, commercially available equipment. Since it is a waste product, the cost to acquire landfill gas is normally much less than natural gas on an equivalent Btu basis. Like all low-Btu fuels (landfill gas has about half the energy density of natural gas), the primary limiting factor is the distance from the landfill to the point of use.
Application of landfill gas-to-energy at the Hill Air Force Base
The Hill Air Force base is located in Layton, Utah. Approximately 2 miles from the base property line is the Davis County landfill. This landfill was opened in 1984 and currently has approximately 2.2M tons of waste in place and is planned to accept about 410 tons of waste per day over the next 20 years. The current gas venting system will be modified to permit the collection, conditioning, compression, and pipeline transport of the gas to the Hill Air Force Base grounds. Historically the landfill gas composition has been 50 percent methane and 50 percent carbon dioxide. In support of the project, the State of Utah Department of Natural Resources will provide funds to help pay for the engineering costs incurred by Davis County. An agreement was reached in November 2003 between Exelon and Davis County/Wasatch Energy to modify the venting system, install all necessary mechanical equipment, and construct an underground pipeline from the landfill to the site with the expense shared by Davis County and Exelon. In addition Exelon has acquired the rights to all gas generated at the landfill for the next 20 years at a pre-determined price.
After transport to the Air Force property, the landfill gas will be combusted in two reciprocating engines that will drive dual generators. The engine-generator sets have been sized to produce 1200 kW of electricity at maximum load and will be operated 98 percent of the year.
- Renewable Energy—8,584,800 kilowatthour annual
production, enough to replace the electricity consumed by 850 homes.
- Energy Cost Savings—approximately $650,000 per year in energy cost savings including payment of the annual cost for the landfill gas.
- Hedge against utility rate volatility—20 year contract at set electric rates.
- Environmental—overall reduced air emissions from renewable energy project and other ECMs projected to be:
CO2 - 5,000 tons per year
NOx - 5.5 tons per year
SOx - 19 tons per year
CO - 4.8 tons per year
This project was somewhat more complex than most Super ESPC projects since a second agreement was needed with a third party, i.e., an agreement with Davis County/Wasatch Energy Systems to acquire the landfill gas. In turn, the second agreement introduced additional risks to the project since supply of the landfill gas over the next 20 years was outside the control of the Air Force and Exelon. Nonetheless a path forward was developed that equitably shared the risks and in the end was satisfactory to all parties involved.
Is There a Biomass/Alternative Methane Resource Close to You?
The BAMF program enables federal agencies with access to wood and paper wastes, landfill gas, municipal wastewater digester gas, coalbed methane, and other organic materials to displace fossil-fuel derived electricity from the grid with electricity generated onsite using local resources that are renewable and, because they are waste streams, relatively low-cost. Development of BAMF Delivery Orders can be done in a relatively short period of time. The time between contractor selection and award of the Delivery Order at the Hill Air Force Base as an example took only 6 months.
For more information, please contact Christopher Abbuehl, BAMF National Program Representative, at 215-656-6995, Craig Hustwit, BAMF Technical Lead, at 304-285-5437; or Danette Delmastro, FEMP BAMF Team Lead, at 202-586-7632.