Avista’s Kettle Falls Generating Station is a biomass fuel generating plant in Kettle Falls, Wash. It began operating in October 1983 and celebrates its 25th year of operations in October 2008.
The plant burns wood waste to produce steam, which runs a turbine and generator that can produce a maximum output of 53 megawatts of electricity. The plant also operates a natural gas-fired combined-cycle combustion turbine that produces 8 MW, bringing the electricity output of the entire plant (including biomass and natural gas-fired operations) to 61 MW; enough electricity to power nearly 46,000 homes.
The plant was the first electric generating station of its kind constructed within the United States for the sole purpose of producing electricity from wood waste.
How the Plant and Biomass Works
- Wood waste – called “hog fuel” – is fed into a seven-story furnace/boiler and burned, creating heat. The walls of the furnace/boiler consist of pipes filled with water that are heated by the burning hog fuel. The optimal burning temperature is 2,000 degrees, resulting in a steam temperature of 950 degrees. The heated water generates stream and pressure that drives a turbine, which turns a generator, creating electricity.
- The term “biomass energy” refers to the organic matter in trees, agricultural crops and other living plant material burned to create energy. Avista’s focus has centered on wood waste of various types.
- The plant burns 70 tons (140,000 pounds) of wood waster per hour during full operations. That amount of fuel would fill two fully loaded semi trucks.
The plant removes 99.9 percent of particulates from flue gas prior to leaving the stack. (.052 pounds of particulate is released per ton of fuel burned.)
The video below "From Wood Waste to Power" was created more than two decades ago and chronicles the dedication of Avista’s Kettle Falls Generating Station in 1983 while providing an overview of its early operations. Due to its age, some statements and facts in the video are dated.