The ColumbiaGrid board of directors recently adopted a 10-year transmission plan that includes 56 new transmission infrastructure projects and enhancements that will cost an estimated $2.5 billion, according to TransmissionHub.
The 2015 Biennial Transmission Expansion Plan contains the information of transmission projects and upgrades within or related to ColumbiaGrid’s footprint, which includes the service territories of Avista, Bonneville Power Administration, Chelan County Public Utility District, Cowlitz County PUD, Douglas County PUD, Grant County PUD, Idaho Power, PacifiCorp, Portland General Electric, Puget Sound Energy, Seattle City Light, Snohomish County PD, and Tacoma Power, a ColumbiaGrid spokesperson told TransmissionHub on March 4.
The plan was coordinated with other sub-regional planning groups, such as the Northern Tier Transmission Group, and with the overall region through the Western Electricity Coordinating Council. Projects in the plan primarily address issues that would occur in the first five years of the 2015-2025 planning horizon. Additional projects will be required to meet the needs in the latter part of the 10-year planning horizon, the plan said.
Transmission projects in the plan are unique to ColumbiaGrid’s member service territories and do not connect the northwest region to the southwest region, the spokesperson said.
Transmission line construction projects included in the plan are:
· BPA’s $99 million, 500-kV Central Ferry to Lower Monumental project, which is under construction and scheduled to be in service this year
· BPA’s $124 million, 500-kV Big Eddy to Knight project, which is scheduled to be in service this year
· Douglas County PUD’s $23.3 million, 230-kV Rapids to Columbia project, which is scheduled to be in service in 2016
· Grant County PUD’s $5 million, 115-kV Rocky Ford to Dover project, which is scheduled to be in service in 2016
· Idaho Power’s $840 million, 500-kV Hemingway to Boardman project, which is scheduled to be in service after 2020
· PSE’s $13 million, 115-kV Woodland to Gravelly Lake project, which is scheduled to be in service in 2019
· Snohomish County PUD’s $25 million, 115-kV Turner to Woods Creek project, which is scheduled to be in service in 2020
Transmission line rebuild and upgrade projects in the plan are:
· Avista’s $10 million, 115-kV Bronx to Cabinet rebuild project, which is scheduled to be in service in 2016
· Avista’s $10 million, 115-kV Benton to Othello rebuild project, which is scheduled to be in service in 2016
· BPA’s $1 million, 230-kV Santiam to Chemawa rebuild project, which is schedule to be in service after 2018
· Cowlitz County PUD’s $4.9 million, 115-kV Longview to Lexington rebuild, which is scheduled to be in service by 2017
· Cowlitz County PUD’s $10.1 million 115-kV Longview to Lexington to Cardwell rebuild, which his scheduled to be in service by 2017
· PSE’s $80 million, 230-kV Sammamish to Lakeside to Talbot rebuild, which is scheduled to be in service in 2018
· PSE’s $25 million, 115-kV Portal Way rebuild, which is scheduled to be in service in 2018
Since the adoption of the 2013 Biennial Transmission Expansion Plan, ColumbiaGrid implemented an economic planning study (EPS) as part of its study programs to inform the planning process, the plan said. The EPS focuses on evaluating future system performance, such as potential transmission congestion or utilization, prices at specific locations or areas, potential production at generation facilities, with the ability to simulate hourly or sub-hourly system behavior using production cost simulation software.
An EPS study in 2014 helped ColumbiaGrid determined the potential effects of various scenarios of installing replacement capacity for known steam coal retirements in the Pacific Northwest.
ColumbiaGrid also incorporated a variable transfer limit study for the California-Oregon Intertie in the biennial plan to determine the ability of the system to accommodate some fluctuation in the power grid without operator intervention, the plan said. ColumbiaGrid may produce an update to the 2015 biennial plan, if warranted, based on the results of ColumbiaGrid’s annual system assessment, which will be completed in July.
Idaho Power is a unit of Idacorp, PacifiCorp is a subsidiary of Berkshire Hathaway, and PSE is a subsidiary of Puget Holdings.