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Puget Sound Energy electric transmission line project

Olympia substation and transmission line upgrade

Fall 2009 project completion
  • Puget Sound Energy completed the $15 million electric transmission system upgrade in the Olympia area on October 23, 2009
Project overview
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Project Map 
(593 KB PDF)

To increase reliability and meet the growing customer demand for power in the Olympia area, Puget Sound Energy upgraded our existing low-voltage 55 kilovolt (kV) substations and transmission lines to our now current standard of 115 kV. The two-year project entailed converting the voltage of – or entirely rebuilding – 11 substations and converting all of the transmission lines connecting the substations to 115 kV.

The 2007-2009 multi-million dollar construction effort includes the following transmission line and substation work:

2007 projects
  • Johnson Hill – Pleasant Glade transmission line: Rebuilt for 115 kV. Construction completed in 2007.

2008 projects
  • Saint Clair substation (9512 Pacific Hwy SE, Lacey): Updated equipment and modified transmission line terminations. Construction completed in April 2008.
  • Hawks Prairie substation (9230 Orion Drive NE, Lacey): Replaced transformer and updated equipment. Construction completed in May 2008.
  • Luhr Beach substation (46th Ave. NE & Meridian, Olympia): Modified existing transformer and updated equipment. Construction completed in May 2008.
  • Valencia substation (Talcott Ave. & Columbia St., Olympia): Removed station equipment and transmission line. Construction was completed in July 2008.
  • Pleasant Glade substation (Pleasant Glade Rd. near Sleater-Kinney Rd., Lacey): Installing additional circuit breakers, updating equipment, and modifying transmission line terminations. Construction was completed in July 2008.
  • Plum Street substation (616 Legion, Olympia): Demolishing existing and rebuilding substation for 115 kV. Construction began in May 2008 and was completed in October 2008.
  • Friendly Grove substation (Friendly Grove Rd. & 26th Ave. NE, Olympia): Constructing a new 115 kV substation adjacent to the existing 55 kV substation, then demolishing the existing substation and modifying existing transmission and distribution lines to accommodate the new station. Construction was completed in March 2009.

2009 projects
  • Olympia substation (Ferry & 9th, Tumwater): Modified transmission line terminations, added 115 kV Line Bay and controls, re-energized at 115 kV, and removed all 55 kV equipment. Construction was completed in spring 2009.
  • Capitol substation (1541 Cherry St., Olympia): Replaced transformers and re-energized at 115 kV. Construction was completed in June 2009.
  • Plum St. substation (616 Legion, Olympia). Converted to 115 kV operation. Construction was completed in July 2009.
  • Thurston substation (Thurston Ave. & Franklin St., Olympia): Replaced transformers, and re-energize at 115 kV.
  • West Olympia substation (2301 4th Ave. W near Black Lake Blvd., Olympia): Installed a new 115 kV circuit breaker and updated equipment, and removed 55 kV equipment.

Workers construct a
transmission line

What is a substation?

Substations are critical links in the electricity distribution system, containing utility circuit protection, voltage regulation, and equipment that steps down higher voltage to lower voltage. Before reaching homes and businesses, power is routed through our transmission system to a substation where it is changed to a lower voltage that can be utilized by customers.

What is a transmission line?

Transmission lines are key elements in the electrical distribution system. The lines safely transport high voltage electricity from power generation sources like dams and wind generating facilities to substations in local communities. Transmission normally takes place at voltages of 55 kV and higher.

Download information

Download these PDF files for more detail on PSE's Olympia area 115kV substation and transmission line conversion.
Project Map (593 KB PDF)