The Short Mountain Power Plant has long been touted as a “win-win” for the Lane County community. The project not only captures methane gas at the County landfill, it turns this harmful greenhouse gas into valuable electricity. Energy produced at Short Mountain is renewable, low cost, and directly benefits the 50,000+ Lane County citizens served by EPUD.
The first phase became operational in 1992 while a second expansion phase was undertaken in 1993. Today, the project generates about 22 million kilowatt-hours (kWh) and approximately 2.5 average megawatts (MW) annually, enough to power about 1,500 homes in our community.
In 1985, EPUD approached Lane County with the concept of a landfill-gas-to-electricity plant. Lane County subsequently put out a request for proposals that was granted to Emerald. In November 1988, Emerald’s Resource Planning Citizens Advisory Committee, a customer committee charged with studying EPUD’s resource strategy, recommended to the Board of Directors development of the Short Mountain Project. After extensive study, a public hearing, and careful analysis, Emerald’s Board of Directors made the final determination to proceed with development in March of 1991.
Benefits to Community
The Short Mountain project brings many benefits to the local community, EPUD, and the Pacific Northwest. As a “green” or “renewable” resource, it is consistent with the resource priorities of our customers and the region. The project also diversifies Emerald’s resource portfolio, supports several full-time jobs, and has a positive economic impact on the community. It uses the best available emission-control technology and significantly reduces methane, a powerful greenhouse gas, which naturally escapes from the landfill. Equally important, Short Mountain is a relatively low-cost resource that will help keep Emerald’s rates stable. Lane County receives a royalty payment each year and has avoided the cost of a multi-million dollar collection system. The project also contributes tens of thousands of dollars per year in property taxes to schools and local and state governments.
Process Description
EPUD is extracting naturally occurring methane from the Short Mountain Landfill through vertical and horizontal wells. The wells are connected in a system of plastic pipes called the collection system, which delivers the landfill gas to the power plant. A blower that creates a vacuum on the collection system draws the landfill gas from the wells. The landfill gas is then filtered and piped directly into large Caterpillar 3516 gas-fired internal combustion engines (1150 horsepower from 16 cylinders generating 800 kilowatts each), where the landfill gas is burned to generate electricity. All ownership and operation of the landfill itself is done exclusively by the Lane County Solid Waste Management Division. EPUD owns and operates the collection system and power plant.
The flow chart above graphically demonstrates the process. Starting at the left, a combination of vertical and horizontal wells extract the landfill gas. Once the landfill gas is extracted from the individual wells, it is piped through the collection system and brought to the power plant. The gas passes through a clean-up system that removes the moisture and filters out particulates and other impurities. After the gas is cleaned, it’s injected into the engine carburetors for combustion. The Caterpillar engines were specifically designed to run on landfill gas. Combustion of the gas in the engines turns the engine crankshafts, which turn the generators, which creates the electricity. Through switching gear and step-up transformers, the electricity is tapped directly into the utility distribution grid for use by EPUD’s customers.
The Environment
The project is extremely beneficial to the environment. Landfill gas is composed largely of methane, which is a powerful greenhouse gas about 22 times more harmful than carbon dioxide. In the combustion process to create electricity, the landfill’s methane is converted to carbon dioxide, thereby significantly reducing the greenhouse effect of the landfill.
The environmental benefit of a plant like Short Mountain is the same as removing 20,000 cars and their emissions, or planting 25,000 acres of forest, or forgoing the burning of 500 railcars of coal! The project also has the benefit of reducing or eliminating the odor problems at Short Mountain.
Concern for the environment also motivated EPUD to choose equipment that uses the best emission-control technology available. The Caterpillar engines are specially designed to be “low emission” engines, low enough to meet the stringent California emission standards. The Lane Regional Air Pollution Authority (LRAPA) approves and permits the project.