Puget Sound Energy last month completed transmission line upgrades along 40 miles of the company’s existing utility corridor between its Sedro-Woolley substation in Skagit County and its Horse Ranch substation near Everett in Snohomish County. The project upgraded PSE’s existing 115-kV transmission line to a 230-kV transmission line and installed a new fiber-optic line, improving electric reliability to utility customers throughout the region and increasing capacity of the regional bulk electric system.

“The upgrade of this line brings important improvements to the entire regional electric system serving the Puget Sound area,” said Dom Amor, manager of local government and community relations for PSE. “This line not only allows us to meet our customers’ current and future demand for electricity, it serves as an important back up for several regional utilities, including the Snohomish Public Utility District.”

PSE began work on the line in May 2009, which involved replacing 300 existing wooden H-frame poles with 300 new monopole steel structures, stringing new conductor and installing a fiber-optic line, which allows PSE to monitor and coordinate the transmission system remotely through instantaneous communications. To accommodate the new line, PSE upgraded its Sedro-Woolley substation and will be upgrading its Horse Ranch substation in 2011.