Puget Sound Energy to add 230-kV transmission to east side of metro Seattle

Puget Sound Energy (PSE) on Dec. 4 announced plans to build 18 miles of 230-kV transmission lines to increase capacity and enhance reliability in a rapidly growing portion of metropolitan Seattle.

The lines will run between existing PSE substations in Redmond and Renton in Washington, and the “Energize Eastside” project will include construction of a new substation in Bellevue. PSE’s engineers and planners have analyzed hundreds of potential route corridors, and have narrowed the possibilities to 16 route segments, which will be discussed at community meetings beginning next January and continuing through 2014.

While acknowledging that the new transmission lines could be co-located with PSE’s existing 115-kV lines, the utility said it will select a final preferred route after evaluating the comments received and after considering various requirements and constraints that might affect the project. At present, the project is expected to cost between $150m and $290m, depending on the final route selected.

The utility hopes to finish the design and obtain the necessary permits in time to begin construction in early 2017 to meet to supply shortfall forecast for 2017-2018.

In announcing the project, PSE officials noted that the area, which stretches from Renton to Bellevue and ultimately to Redmond is growing faster than any other region in Washington and has transitioned from its previous incarnation as being made up of [?] bedroom communities for Seattle to becoming a major economic and employment center. The area is home to 140,000 jobs, numerous small businesses and 143 corporate headquarters, including software giant Microsoft (NYSE:MSFT), retailer Costco (NYSE:COST), as well as a plant where airplane manufacturer Boeing (NYSE:BA) builds 737 jetliners.

Projections show customer demand will exceed PSE’s ability to supply reliable power as soon as the winter of 2017-2018, according to the utility. Without an upgrade, the area’s transmission system will lose redundancy, increasing the possibility of outages for as many as 60,000 area homes and businesses, the utility said.

“PSE and its customers have taken significant steps to get the most out of today’s system, including substantial conservation actions,” the utility said. “Still, conservation alone is not enough.”

In addition to increasing capacity, the project will help harden the utility’s transmission system.

“The Energize Eastside project will help our area continue to attract new jobs and withstand severe storms,” Andy Wappler, PSE’s vice president of corporate affairs, said in the statement.