LANDFILL-GAS-TO-ENERGY PROJECTS: AN ANALYSIS OF NET PRIVATE AND SOCIAL BENEFITS. By: Paulina Jaramillo.
LANDFILL-GAS-TO-ENERGY PROJECTS: AN ANALYSIS OF NET PRIVATE AND SOCIAL BENEFITS
In addition to preventing the emission of landfill gas to the atmosphere, landfill-gas-to-energy projects could indirectly reduce air pollution from fossil fuel combustion by offsetting the use of these fuels to generate electricity.
To evaluate total private and social benefits of landfill-gas-to-energy projects.
Landfill-gas is collected by a system of wells and pipes installed throughout the landfill
Source: U.S Environmental Protection Agency. Turning a Liability into an Asset. Landfill Methane Outreach Program. Washington, DC 1996. EPA 430-B-96-0004.
- T is the current year
- 2 is the Ratio of landfill gas to methane.
- Rx is the amount of waste disposed in year x (lbs).
- Lo is the total methane generation potential of the waste = 2 cf/lb
- k is the rate of methane generation = 0.04/yr
- x is the year of waste input.
LFG the atmosphere, landfill-gas-to-energy projects T = ∑LFGT,x
Three landfills located in St. Louis, Missouri
Source: Morgan, Susan M. and Yang, Qing. Use of Landfill Gas for Electricity Generation. Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management. January 2001.
Where 0.5 is the assumed percentage of landfill gas that is CO2/CH4; 0.112 are the lbs of CO2 per cf of landfill gas; 0.041 are lb of CH4 per cf of landfill gas; and LFGT is the total amount of landfill gas generated in current year T (cf).
Where collection efficiency is assumed to be 85% and 2.75 is the ratio of the molecular weight of CO2 to the molecular weight of CH4
Similar method for other pollutants (SO2, etc)
Calculated using the average emission factors (based on all energy sources) for the region of St. Louis - MO, as given by the EPA’s E-GRID program.
- 1,237 lb/MWh for CO2
Note: Values are in thousand dollars
Divide the emission savings NPV by the electricity generated during the operating life of the project.
Subtract the private NPV from the emission savings NPV, and divide by the electricity generated during the operating life of the project.