| Oregon's Use of Biomass Energy |
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| Overview |
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Biomass sources supplied approximately 75 trillion Btu of useful energy in 2004, primarily for industrial purposes and home heating. Biomass energy facilities in Oregon generated approximately 1,130 million kilowatt-hours of electricity in 2004.
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| Industrial and Commercial Biomass Energy |
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There are wood fiber biomass combustion boilers at 49 industrial sites in the state. The boilers supply heat for industrial processes. At ten of these sites, steam-driven generators produce electric power. The energy generated at these facilities was about 942 million kilowatt-hours in 2004. The facilities consumed approximately 1.6 million bone dry tons of biomass fuel in 2004 with an energy value of about 27 trillion Btu.
In addition, six pulp mills in Oregon operate chemical recovery boilers. The gross energy value of the pulping liquor burned in these facilities in 2004 was about 35 trillion Btu. All of the mills use these boilers to produce steam for industrial processes. Two pulp mills cogenerate steam and electricity, producing 206 million kilowatt-hours of electric energy in 2004.
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| Home Heating with Biomass |
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Firewood from Oregon´s forests has long been a biomass resource for home heating. Private individuals and commercial companies cut firewood from public and private forest lands in the state. Scrap and salvaged wood are other sources of wood fuel for home heating use. Twenty-two percent of Oregon households use wood heating as either their main method of space heating or as a back-up heating resource. The Oregon Department of Energy estimates that about 490,000 cords of firewood were consumed in 2004. The energy value of this heating source was about 10 trillion Btu.
Two Oregon companies produce pellet fuel and one produces charcoal briquettes. Oregon manufacturers produced about 239,000 tons of these fuels in 2004. The energy value of the fuel was about 4.5 trillion Btu.
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| Municipal Solid Waste Combustion |
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The state´s only municipal solid waste-to-energy facility is located near Brooks, Oregon, in Marion County. The facility, owned by Covanta Marion, Inc., has been operating since 1986. The combustion facility burns unprocessed municipal waste. It consists of two furnaces with a design capacity to burn 550 tons of waste per day. In 2004, the energy value of the municipal solid waste the facility consumed amounted to about 1.7 trillion Btu. The facility generated 99.2 million kilowatt-hours of electric energy.
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| Biogas |
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Wastewater Treatment
Anaerobic digesters are part of the sewage treatment process at 28 large wastewater treatment plants in Oregon. These wastewater treatment systems have an average wastewater flow rate of at least one million gallons per day. The digester gas produced at these facilities in 2004 had an energy value of about 0.8 trillion Btu.
Wastewater treatment plants use digester gas on site as boiler fuel to produce heat for the anaerobic digestion process and for space heating. Nine wastewater treatment plants use digester gas as fuel to generate electricity. The plants generated about 26 million kilowatt-hours in 2004.
Organic Waste Digesters
Animal manure digesters can be designed for individual farm operation or as centralized facilities. The Tillamook Digester Facility began operating in 2003. The digester converts manure from approximately 4000 dairy cows into electricity. In 2004, the facility generated about 1.3 million kilowatt-hours of electricity.
Portland General Electric (PGE) has built a small manure digester at CalGon Farms dairy in Polk County. It handles the manure from about 400 dairy cows and generated about 236,000 kilowatt-hours of electric energy in 2004.
Landfill Gas
Two landfills in Oregon generate electricity from landfill gas. Landfill gas-to-energy facilities at Short Mountain in Lane County and at Coffin Butte in Benton County generated about 36.5 million kilowatt-hours of electric energy in 2004.
Ash Grove Cement Company uses gas from the now-closed St. Johns Landfill in Portland to heat its lime kilns, displacing the use of natural gas and oil. At River Bend Landfill in Yamhill County, landfill gas is burned to evaporate landfill leachate. These two direct-use landfill gas facilities produced about 0.45 trillion Btu of energy in 2004.
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