Composite Power Line Offers Hope to Strained Systems
Staff -- Consulting-Specifying Engineer, 12/1/2005
A new type of transmission line promises utilities more than twice the transmission capacity of conventional lines while using existing towers and other equipment. The aluminum conductor composite reinforced (ACCR) line, developed by 3M, was first installed in the Minneapolis-St. Paul area in May. In January, lineman will begin a second installation—a 20-mile stretch that parallels the Colorado River along the Arizona-California border.
The ACCR is a new type of bare, overhead conductor line that contains a multi-strand core of heat-resistant aluminum matrix composite wire. The material has been field-tested, and has been shown to retain its strength at high temperatures, without being affected by other adverse environmental conditions such as moisture or UV exposure.
Utilities and transmission systems have run into difficulties getting new transmission lines approved in recent years, even as electricity demand has grown. The ACCR material is lighter, with reduced thermal expansion properties compared with traditional materials, which means ACCR line can be installed on existing towers without causing any visual changes or requiring any additional rights of way.
It is expected the Arizona line installation will be completed by April 2006. Plans call for eventually extending the line an additional 60 miles north to Lake Mead at Boulder Dam in Nevada.
