Greenville County SC Landfill Gas to Energy Project
» Please submit comments by January 11, 2012 to projects@terrapass.com.
The Enoree Landfill is a small, municipally-owned solid waste disposal facility in Greer, South Carolina which closed in 2007 after 12 years of use. Due to its small size, the landfill’s closure plan did not require an active gas management system, in which methane from decomposing trash is pulled from the landfill and destroyed. Nonetheless, Greenville Gas Producers LLC, funded and installed a gas collection system, flare, and later a landfill gas-to-energy system which depends on carbon credit revenues to create a reasonable investment return. Installing such a system on a small, closed landfill is not at all common and represents a great use of TerraPass funds.
Project details
The Enoree Landfill is a municipal solid waste landfill owned and operated by Greenville County. The landfill started accepting waste in 1996 and was closed in February 2007 with 2,573,786 tons of municipal solid waste. It had a design capacity of roughly 2.86 million tons of waste.
Landfills emit methane, a powerful global warming gas, as organic matter deposited in the landfill degrades. Landfills are conducive to methane production because their compaction, linings, and cover systems virtually eliminate oxygen within the waste mass such that decomposition occurs in an anaerobic fashion, and methane is a primary product of anaerobic decomposition.
Large landfills are generally required to collect and destroy methane gas as it is generated, so that it is not emitted into the local environment. However, small landfills emit so little methane and other pollutants that they are generally not required to control their emissions.
Greenville Gas Producers, managed by Enerdyne Power Systems of Charlotte, NC, took the unusual approach of funding a gas collection system and power generation plant, even though the gas supply will by necessity decline year over year. The project had other unusual factors weighing against it as well; for example, the local utility decided it did not want, nor was it required, to purchase the plant’s electricity. So the project included a new electricity line over a mile long to a different utility’s system so the power could be sold.
To overcome these barriers, Greenville Gas Producers assembled a collection of revenue streams to pay for the project investment. These include the electricity and renewable energy credits, as well as carbon credits. All revenue streams were necessary to create an investment return that could support the $5 million in upfront capital required.
Today, the project includes the gas collection system that pulls methane into pipes before it can be emitted into the air, and two Caterpillar engine-generators with a combined 3.2-megawatt generation capacity. By destroying methane in the generators, the landfill’s emissions change from methane, with a global warming potential about 25 times greater than carbon dioxide, to carbon dioxide itself – mimicking natural degradation and creating a balanced carbon cycle
Project location
The project is located in Greer, South Carolina, about 85 miles southwest of Charlotte, North Carolina.
Other social and environmental benefits and costs
Environmental benefits
- Improvement of air quality, such as volatile organic carbon emission reductions
- Prevention of odor in surrounding areas
Social benefits
- Construction and maintenance jobs related to the project
- The project provides revenue for Greenville County
Project’s environmental and social costs
- There are no major environmental or social costs associated with this project
Discussion of appropriate use of TerraPass funds
TerraPass considers many aspects of projects before deciding whether to fund them. Here is a summary of key considerations for this project:
Baseline conditions
Before the project, the landfill was venting all of its gas to the atmosphere. Carbon offsets are helping to reduce greenhouse gas emissions by tens of thousands of tons per year.
Additionality
No regulatory requirements. There are no state or local regulations that require the landfill to collect methane gas. The project was entirely voluntary, funded by an investor who hoped to earn a return; no other complicating motivations were present.
Impact of TerraPass funds. TerraPass seeks projects where the funding from our purchases helps assure a positive financial outcome for the greenhouse gas emission reduction project. Because this project is on a small, closed landfill, all revenue sources were required to provide a suitable return on the initial project investment.
Better than most. TerraPass seeks projects that show unusual stewardship or other forward-looking motivations. The Greenville County project was one of the first landfill projects in the United States validated to the Voluntary Carbon Standard (along with another TerraPass project, the Greater Lebanon Refuse Authority). These Validation documents include a third-party verified financial analysis of the project and its investment returns, confirming the requirement for carbon revenue in the project’s finances. In addition, the very early commitment to establishing carbon credits using rigorous international standards was a laudable forward-looking approach. For these and other reasons, this project is a past winner of the EPA’s Landfill Methane Outreach Program’s “Project of the Year” award.
