The ColumbiaGrid board approved and adopted its 2012 Biennial Transmission Expansion Plan Update on Feb. 15, 2012. The 10-year outlook includes $2.3 billion in planned transmission additions.

ColumbiaGrid engineers had completed an independent assessment of adequacy of the regional grid in July 2011 and then organized cooperative study teams to address deficiencies and develop solutions. The study teams, which included ColumbiaGrid participants along with engineers from adjacent interested utilities, made sure their recommendations would meet national and regional reliability standards.

The ColumbiaGrid transmission expansion plan also covers sensitivity studies conducted to test the ability of the transmission system to withstand continued operation during major transmission outages and light load conditions in addition to investigation of the voltage stability issues identified in the system assessment.

Engineers at ColumbiaGrid are already at work on the 2012 system assessment study. New problems identified in the assessment will be addressed later in the year in the 2013 Biennial Plan. Work on Gas-Electric Interdependencies and local wind sensitivities will also continue throughout the year.

ColumbiaGrid, a non-profit membership corporation, was formed in 2006 to improve the operational efficiency, reliability, and planned expansion of the northwest transmission grid. The members are Avista Corp., Bonneville Power Administration, Chelan County PUD, Grant County PUD, Puget Sound Energy, Seattle City Light, Snohomish County PUD and Tacoma Power. Cowlitz PUD, Douglas County PUD and Enbridge Inc. are non-member participants in PEFA.