Tri-State acquired about 200,000 customers in New Mexico when it bought Plains Electric Generation and Transmission Cooperative in June 2000. It supplies residential and business customers through sales to 12 rural electric cooperatives in 27 counties in the state. In order to move power from the proposed new plant, Tri-State and other transmission line owners in Colorado would have to make improvements to the existing lines, said Van Someren. In choosing coal, Tri-State is moving in a different direction from most new plant developers. Most plants now under construction or being planned are fired by natural gas.
Natural gas is considered a cleaner fuel and until a year ago was cheaper.
But increased demand has led to tighter gas supplies and higher prices. Environmental groups in Colorado have raised arguments against building a coal-fired plant, saying there are cleaner and cheaper ways to provide electricity in the region. But Tri-State says it has considered all aspects of the project and can use coal with very little environmental impact. Coal for the new plant would come from either Wyoming's Powder River Basin or the Western Slope in Colorado, said Van Someren.