American Transmission Co. (ATC) has placed in service a new 138-kV, 16-mi line between Eagle River and Conover, Wisc., bringing needed power to northern Wisconsin and western Michigan. Construction will then continue on a related project between the Conover Substation and the Plains Substation in Norway, Mich. (Cranberry-Iron River-Plains project). The electric transmission infrastructure serving northern Wisconsin and the western Upper Peninsula of Michigan is in need of reinforcement. Significant growth has occurred in the Rhinelander/Eagle River area, resulting in an overloaded system that is vulnerable to interruptions and even blackouts under severe conditions, according to ATC.
The lines to the east that connect northern Wisconsin and the Upper Peninsula are the most severely constrained in the ATC system. The constraints limit ATC's ability to move power in and out of the Upper Peninsula, requiring higher-cost generators on the system to run more often, costing ATC customers million of dollars a year. In addition, there is limited ability to schedule maintenance on these lines, resulting in reduced reliability and increased operating costs.
Construction of the Cranberry-Conover line began August 2007. Work on the Conover-Iron River-Plains project entails the conversion of about 73 mi of existing 69-kV lines to 138-kV operation between Lakota Road and Quinnesec, MI. Expected completion date is June 2010.