POWER CABLE Lighter weight, lower line loss, wired to partner with power

Oct 01, 2007 | 03:11 PM |

With aluminum, it's all about give and take. Aluminum production consumes a great deal of electricity, but the material itself gives back as a major component of power transmission systems.

The metal has been the material of choice for electrical transmission applications for more than 100 years for investor-owned utilities, rural electric authorities and electrical cooperatives, said Ian Hewett, president of the Alcan Cable unit of Alcan Inc., Montreal.

Aluminum cable accounts for the vast majority of the 212,000 miles of existing transmission lines that exceed 230 kilovolts in North America, Hewett said.

"The key advantages of aluminum are its light weight, high strength and reliable performance over many diverse operating environments around the world," Hewett said. "Aluminum cables are the most economical solution for transporting power over long distances compared to copper or other conductive materials."

He pointed to the price and performance advantage of aluminum cable for transmission applications compared to other materials. "It takes 2 pounds of copper to equal 1 pound of aluminum for the same current-carrying capacity, and the tension to support copper is much greater than aluminum. The higher material cost of copper and the increased tension requires more steel in the towers and more concrete in the foundations." And at less than half the price of copper cable, aluminum cable offers substantial cost savings when used in long-distance electrical transmission, Hewett said, although he could not provide actual cost comparisons. (From a pure metal standpoint, copper is nearly three times more expensive than aluminum $3.30 per pound for copper vs. $1.15 for aluminum based on recent London Metal Exchange three-month settlement prices.)....