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Puget Sound Energy transmission line project

Lake Hills-Phantom Lake 115 kV transmission line

Fall 2014 project updates

  • We have selected the proposed project route and are in the permitting and engineering phase. The City of Bellevue hosted a public hearing to review PSE's permit application on Nov. 20.
  • We expect to begin construction of the line along NE 8th St and 148th Ave SE in late 2015, depending on permitting.
  • After talking with the City of Bellevue, we have decided to postpone construction of the half-mile line segment along SE 16th St between 148th Ave SE and the Phantom Lake substation so we can minimize disruption by timing with a future road improvement project.

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Project overview

The electric system serving the Lake Hills neighborhood of Bellevue has limited reliability, increasing the possibility of outages for customers. PSE’s Lake Hills and Phantom Lake substations are served radially, which means they are each served by one transmission line. If the radial line serving a substation goes out, the substation and the customers served by that line lose power. In addition, because the substations are served radially, we are unable to use each of the substations’ full design capacity.

To help solve these problems, PSE plans to build a new transmission line between the Lake Hills and Phantom Lake substations. The new transmission line will create a "loop", which means each substation will be connected to two transmission lines. If one line goes out, the other line will still feed the substation and provide power to customers. In addition, the new line will enable PSE to make future use of each substation's full design capacity. This project will increase overall system reliability and allow for better use of existing facilities for customers in the Lake Hills neighborhood.

PSE has selected a proposed route corridor along NE 8th St, 148th Ave SE, and SE 16th St.

The City of Bellevue is planning a future public improvement project along SE16th St. PSE plans to postpone construction of the segment of line along SE 6th St so we can collaborate with the city on design and construction for their project and ours. We believe this plan allows us to minimize construction impacts to neighbors along SE 16th St, as they will be limited to one construction timeframe rather than two. The timeline for the city’s project is to be determined.

What is a transmission line?

Transmission lines are key elements in the electrical distribution system. These 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.

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.