What’s new in our portfolio?

Work is beginning in Oshkosh along Highway 41 to install a new 138-kV circuit in the corridor that currently links the Ellinwood and Sunset Point substations.  Six structures will be replaced and six new structures will be added. The remaining structures on this 4-mile line, which crosses a portion of Lake Butte des Morts, will receive new “arms” to support the new circuit. The new circuit will improve reliability in the immediate area as well as the greater Fox Valley.

A 50-year-old transmission line in Michigan’s Upper Peninsula is being rebuilt to improve reliability by providing increased protection from lightning.  Widespread power outages may occur if a transmission line is struck by lightning. Work on the 14-mile line between Houghton and Laurium should be complete in late spring 2008.

Construction of the underground portion of the Cranberry-Conover line in Eagle River also begins this month. Burying a four-mile portion of the line is necessary to avoid conflicts with the local airport.

ATC recently announced final route options for the proposed Rockdale-West Middleton project in Dane County. The two options follow east-west corridors between the towns of Middleton and Christiana. The northern route generally follows the Beltline corridor and the southern option uses mostly rural areas offset from county highways. Several variations that provide alternate connections between the two routes also will be included when ATC submits its construction application to regulators in October.

Delgado addresses regulatory conference

ATC CEO José Delgado addressed state regulators from 15 Midwestern states at the Mid-American Regulatory Conference in Minneapolis recently. In his remarks, Delgado emphasized that transmission owners and regulators have the same obligation – to serve the public by delivering electricity safely, economically, reliably and with fair and open processes. A repeated topic at the conference was the call for more and better cooperation across state boundaries in the areas of transmission planning, regulatory review and the development of markets and access to renewable generation.

Did you know?

When most people picture a transmission line in their mind’s eye, they see large, lattice-steel towers. That’s not surprising since it was a common design 50 or more years ago when much of the country’s power grid was expanded for reliability and economic reasons. 

Today, a number of factors influence the design of electric transmission lines and structures, including the condition and use of the land and surrounding area, and the voltage of the line.  Single-pole structures are commonly used, and can be either wood or steel. A single-circuit transmission line, as shown here, has three wires, generally made of aluminum, which is light and less costly than copper. A thinner, shield wire is placed at the top of the pole to protect the wires that carry current from lightning. (See story above about the Laurium project.)