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Puget Sound Energy electric transmission line and substation projects
Spurgeon Creek substation, switching station and transmission line projects
Winter 2014 project updates
- Upgrades to existing distribution lines along Diagonal Road, Rich Road and Rainier Road were completed in late 2013
- Construction of the substation is expected to take place in 2015 and 2016
- We are currently in the route selection phase for two of the future transmission lines, and will update the public on the project's progress as soon as we have more information to share
- Construction of the transmission and new distribution lines is expected to begin in 2016 and be completed in 2018
About 25,000 customers in Thurston County are currently served by one 13-mile 115 kilovolt transmission line between Lacey and Tumwater (see map). This line provides power to four neighborhood distribution substations in the Olympia and Lacey areas, which are approaching electric capacity limits in meeting customer demand. In addition, if the line serving these substations experiences an outage, a significant number of customers lose power, because there is not enough redundancy in the electric system to serve them on another line. To solve these problems and ensure customers’ electric needs are met now and in the future, Puget Sound Energy plans to upgrade the electric system in southeast Olympia and southwest Lacey, increasing capacity and improving reliability for customers in the area. We plan to build a new electric distribution substation, a new transmission switching station, and associated transmission and distribution lines.
The multi-year construction effort includes the following projects and expected timelines:
- Upgrade existing distribution lines along Diagonal, Rich and Rainier roads
- Construct a new distribution substation at 7802 Diagonal Road SE in Olympia
- Construct a new transmission switching station at 7802 Diagonal Road SE in Olympia
- Construct three new 115 kV transmission lines (see map)
- Two lines will run from the new switching station to two points on our existing 115 kV transmission line along Yelm Highway Southeast
- One line will run from the new switching station to the Airport substation, located at 910 93rd Ave. SW in Tumwater
- Construct associated 12.5 kV distribution lines
What is a substation?
Substations are critical links in the electricity distribution system, containing utility circuit protection, voltage regulation, and wiring that steps down higher voltage to lower voltage. Before reaching homes and businesses, power is routed through the transmission system to a substation where it is changed to a lower voltage that can be utilized by customers.
What is a switching station?
A switching station is a transmission substation where the utility can switch or reroute power flow from one line or path to another to allow the power to be isolated to clear a fault (e.g., a fallen tree in the wires) or to take the power line out of service for maintenance. It also may act as a point of interconnection between two different transmission operators (e.g., Bonneville Power Administration and PSE). Unlike a substation with a transformer serving neighborhood circuitry, switching stations do not step power up or down; they integrate power from one or more transmission sources on the regional and local grid to serve neighborhood substations.
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.
Committed to keeping you informed
PSE will continue to provide updates to the community. We will notify residents and businesses near the project area when construction will occur. We aim to complete the work with as little disruption as possible.
Download the information
March 22, 2011 public meeting
Public meeting invite, March 2011
Community ad, March 2011
Why outages differ
Existing conditions aerial map
What is happening to your local electric system?
Reliability: Before and after
Project benefit area
Thurston County area projects
Spurgeon Creek site plan
Spurgeon Creek landscape plan
Route selection criteria
Examples of typical transmission lines
Undergrounding transmission lines (Revised August 2012)
Utility landscaping zone
Project aerial map
Project fact sheet, March 2011