Methane gas captured at a landfill near Mora, Minnesota is SMMPA’s newest renewable energy resource. The SMMPA Methane to Electricity Facility was completed and operational April 2012. Under a 20-year agreement with the East Central Solid Waste Commission (ECSWC), a group of five counties in Minnesota that owns the landfill, and in partnership with the City of Mora, SMMPA purchases methane gas from decomposing waste and uses it to fuel a 1.6-megawatt generator that provides power equal to about what 1,600 households use, to SMMPA’s member municipal electric utilities. Municipal solid waste, collected from a wide area in Minnesota, is transported to and stored at the ECSWC landfill near Mora in Kanabec County.
ECSWC operates and maintains the methane collection system to provide an adequate supply of renewable fuel to the generator system. SMMPA designed, financed and manages the project and operates the generation equipment. SMMPA also designed and installed 4.5 miles of 12.5-kilovolt underground cable linking the project to the distribution system of Mora Municipal Utilities, a SMMPA Member. Mora Municipal Utilities owns and operates the electrical distribution system fed by the landfill gas generator. The utility also provides technicians to maintain the engine and generator.
The Generator Set is a new Caterpillar model G3520C Landfill Gas1600 EKW for continuous duty operating at 4160 Volts, 3 phase, 4 wire at a frequency of 60 HZ, 1200 RPM.
Twelve percent of the energy SMMPA supplies to its 18 Member communities comes from renewable and carbon-free sources.
The project came about through a unique partnership among organizations with varied purposes - ECSWC, the City of Mora and SMMPA. Each recognized the value and worked together for the common good.
The landfill is located in Kanabec County, which is a Member of the ECSWC. Mora Municipal Utilities is directly interconnected with the generator outlet line and provides operators and mechanics to operate the facility.
After learning about the leachate recirculation system employed at the land fill and the resulting enhanced methane production, SMMPA met with landfill officials and began a series of studies to determine the feasibility of installing a generating plant. SMMPA began negotiations with ECSWC to purchase the methane then being flared. After planning a viable project, SMMPA worked with the Mora Municipal Utilities Commission to assist with the electrical interconnection and to supply field service technicians. Soon after that SMMPA entered into what became a long process to obtain permitting, and the permit was issued in the fall of 2010. Equipment was ordered and construction began in the spring of 2011 with commercial operations in April 2012.
Prior to the generation project, the landfill had been flaring the methane from the site. However, for all methane gas that is diverted to the generator, the project changes the method of methane destruction from flaring to electricity generation. Today the project reduces 3,187 tons of methane and reduces .0681 million metric tons of CO2, with the added value of reliable electricity production.
At the time the project was conceived and initiated, it represented SMMPA's lowest-cost renewable resource alternative. Depending on the alternative the project was compared to (such as wind and other biomass options), expected savings from pursuing the landfill gas generation project ranged from 12% to 70% over the 20-year expected life of the project.
SMMPA’s cost for installing this renewable generation was $3.7 million. East Central Solid Waste Commission was responsible for the costs associated with supplying the landfill gas to the engine. No tax dollars were spent on this project. The facility is expected to generate electricity at least 90% of total available annual hours (8760 hours).
A goal of the partnership is to add a second generator to the project site assuming methane production levels are adequate. The ECSWC has obtained a permit to expand its existing municipal sanitary landfill in two construction phases to increase waste capacity by about 968,000 cubic yards.