Alabama Power Co. will install 3M’s high-capacity Aluminum Conductor Composite Reinforced (ACCR) transmission conductor to upgrade a key line at its Miller Steam Plant. Alabama Power is a subsidiary of Southern Company, whose utilities also provide power and other services in Georgia, Mississippi and the Florida panhandle. The Miller Plant is located in Jefferson County, Alabama, approximately 25 mi northwest of Birmingham.

Alabama Power’s 1.7-mi upgrade, using 3M ACCR 1033 kcmil 54/19 Curlew, will boost transmission capacity on a line that goes through and loops around the Miller Steam Plant. The upgrade is part of Alabama Power’s ongoing, multibillion-dollar environmental initiative, designed to reduce emissions from the company’s power plants, while continuing to meet the growing demand for power.

The population of greater Birmingham is now estimated at 1.08 million, making it the largest metropolitan area in the state. The new 230-kV line, scheduled for installation this spring, will be rated to carry up to 2,000 A and is expected to peak at a temperature of 200 degrees Celsius.

“The characteristics of the 3M conductor provided the ideal solution for the particular challenges faced with the line reconductor at the Miller Steam Plant,” said Howard Samms, a senior engineer at Alabama Power. He explains: “The existing line crosses below three 500-kV lines and above one 230-kV line and is supported on five existing lattice steel structures. The 3M conductor allowed us to obtain the required capacity, while utilizing the existing structures and maintaining or improving the existing clearances to ground and other obstacles. As a result, significant savings were achieved in both time and cost by eliminating the need for the design, supply and construction of new towers.”

3M ACCR can carry more than twice the current of conventional steel-core conductors of the same diameter, generally with no new tower construction or rebuilding because of its relatively light weight, low sag and high strength. Western Area Power Administration, Xcel Energy, Arizona Public Service, and Shanghai Electric Power in China are among the major utilities that have deployed the advanced conductor to alleviate or preclude peak-demand bottlenecks in major metropolitan areas.

3M ACCR’s strength and durability result from its core, composed of aluminum oxide (alumina) fibers embedded in high-purity aluminum, utilizing a highly specialized and patented process. The constituent materials are chemically compatible with each other and can withstand high temperatures without adverse chemical reactions or appreciable loss in strength, even over long periods of time.