Opened in 1999, the Kiefer Landfill landfill gas-to-energy plant pulls gases from decaying garbage in landfill waste. Gas is pulled via 215 extraction devices placed directly into landfill. These gases are used to run five Caterpillar internal combustion engines that turn generators to make electricity. The Sacramento Municipal Utility District (SMUD) purchases the electricity to power 8,900 homes.

Landfill Gas-to-Energy Process:

• Landfill gas is created when waste in a landfill decomposes
• This gas is about 50% methane and 40% carbon dioxide with traces of other gases
• There is no difference between an electric generating plant using landfill gas and one using natural gas or diesel fuel.

Three Basic Components:

1. Gas Collection System: Gas is collected from decomposing waste by a series of wells strategically placed throughout the landfill. The number and spacing of wells depend on specific aspects such as volume, density, and moisture content. Wells are constructed by drilling holes to within 15 feet of the bottom of the landfill. Perforated plastic pipes are inserted into the wells. The area around the pipes is filled with large gravel to prevent refuse from plugging the perforations. The wells are connected by a series of pipes leading to larger, header pipes that deliver the gas to the energy facility. The entire piping system is under a vacuum created by blowers at the energy facility, causing landfill gas to flow from the wells.

2. Energy Facility: Once blowers deliver the gas to the energy facility, internal combustion engines use the gas as fuel and spin generators to produce electricity.

3. Grid Connection: After the gas is converted to electricity, a dedicated power line is used to deliver the electricity to SMUD power distribution system. Grid connection includes metering equipment necessary to monitor sales and system protection equipment with emergency shutdown capability.

Facility/Plant Information:

The energy facility uses five Caterpillar G3616 internal combustion engine generator sets (like train locomotive engines), which have been specifically configured to use landfill gas as fuel. The electricity generated by the landfill gas-to-energy project ties into the existing SMUD distribution line on Jackson Highway. Landfill Energy Systems Inc. has been contracted by the County to run the plant. This includes plant operations and maintenance. SMUD purchases the electricity for use in their Green Energy program. The KLb1 facility cost $14 million to construct. Financing was obtained through revenue bonds.

Environmental Issues:

• The decomposition of waste in landfills produces a gas which is composed primarily of methane and carbon dioxide. These compounds contribute to the formation of ozone, a primary cause of smog and are also greenhouse gases contributing to global climate change. Landfills are the largest source of human-based methane emissions in the US, constituting almost 40 percent of these emissions each year.
• Landfill gas is a potentially harmful emission that can be converted into a reliable energy source used to generate electricity.
• The methane component, which represents roughly half the volume of the landfill gas, is burned in internal combustion engines. Combustion of landfill gas converts methane to carbon dioxide and water vapor. Given that methane's global warming potential is 23 times that of carbon dioxide by weight, this conversion results in a significant positive benefit to the global atmosphere.
• Potential environmental impacts in the vicinity of the landfill due to emission of landfill gas to the air are controlled by collection of escaping gases.
• Landfill gas also poses a potential threat to groundwater.  Methane and CO² often act as a carrier gas for trace VOCs, which impact groundwater.
• In addition to greenhouse gas reductions, the capture and use of landfill gas provides the ancillary benefits of limiting odors, controlling damage to vegetation, reducing owner liability, risk from explosions, fire and asphyxiation, and smog while providing a potential source of revenue and profit.
  

Project Benefits:

• Landfills produce methane, a greenhouse gas. The Kiefer Landfill Gas-to-Energy Plant captures methane gas for use as a source of electricity and reduces greenhouse gas emissions. This reduces dependency on fuel oil, which is a standard fuel for boilers.
• Producing electricity from landfill gas creates a beneficial use. Landfill gas burned off in the open air with no energy recovery provides no beneficial use.
• By using landfill gas as a fuel source, the project converts a potential pollutant into a useful product. This project is a ‘win-win’ solution to an environmental challenge.
• The landfill gas-to-energy plant produces 14.0 megawatts of electrical power, enough capacity to serve more than 8,900 households for over 20 years.
• The amount of gas recovered by this project yields the same reduction in greenhouse gases as:
  
• Removing 117,000 cars from the road for one year, or
• Planting 167,000 acres of trees.

Landfill Gas-To-Energy Projects In The United States:

• There are more than 400 operating landfill gas-to-energy projects in the country and about 600 landfills that are good candidate sites.
• To date, landfill gas-to-energy projects have prevented the release of 1.5 million tons of carbon into the atmosphere. This reduction is equivalent, in pollution terms, to removing 1.1 million cars from the road.