Colstrip Power Plant, near Colstrip, Mont.

The Colstrip power plant, east of Billings, Mont., operates four coal-fired generating units capable of producing a total of up to 2,094 megawatts* of electricity. Units 1 and 2 began commercial operation in 1975 and 1976, and Units 3 and 4 started in 1984 and 1986. Units 1 and 2 each have about 307 megawatts of generating capacity; PPL has 50 percent ownership of each.

Units 3 and 4 each have about 740 megawatts of generating capacity; PPL has 30 percent ownership in Unit 3 and no ownership in Unit 4. PPL's share in the plant's generating capacity is 529 megawatts.

The plant employs about 360 people and is owned by PPL Montana LLC, a subsidiary of PPL Generation LLC, as well as Puget Sound Energy Inc., Portland General Electric Company, Avista Corporation, PacifiCorp, and NorthWestern Energy LLC.

The Colstrip facility is the second largest coal-fired project west of the Mississippi. It uses one rail car's worth of coal every five minutes, compared to the Corette plant, which uses one rail car's worth of coal every hour. 

Low-sulfur coal and state-of-the-art scrubbers restrict sulfur dioxide emissions to less than levels required by both Phase One and Phase Two of the Clean Air Act. The plant also meets Environmental Protection Agency standards for nitrogen oxides emission.

The plant consistently ranked as one of the lowest cost fuel plants in the Western Electricity Coordinating Council, a regional member of the North American Electricity Reliability Council that includes all the western states and the Canadian provinces of Alberta and British Columbia.

In October 2007, the plant became one of only three industrial sites in Montana to hold the "Star" certification in the U.S. Occupational Safety and Health Administration’s Voluntary Protection Program.

*winter capacity as of August 2006.