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Energy Celilo DC Converter Station – Pacific DC Intertie Upgrade
An electrical substation with grids of metal pylons and transformers beside a parking lot, an American flag, and dry rolling hills under a clear blue sky.
Project Location
The Dalles, OR
Client Bonneville Power Administration
Market Sector
Project Type
  • Transmission & Distribution
Services Provided

Project Highlights

  • Installed a ±560kV bi-polar converter station rated at 3,800 MW at the Celilo site.
  • Executed complex civil work, including tower and equipment foundations, grading, roads, and walkways.
  • Delivered under an Engineer-Procure-Construction (EPC) contract with a tight schedule and spatial constraints.

Project Description

The Celilo DC Converter Station upgrade was a major infrastructure enhancement for the Bonneville Power Administration in The Dalles, Oregon. The project involved replacing nearly all equipment from the existing Celilo converters 1 and 2 with a newly furnished ±560kV bi-polar converter station capable of handling 3,800 MW. The upgrade also included a communication interface system and integration with a 500kV AC substation, enabling seamless coordination with the Sylmar Converter Station.

MacKay Sposito provided comprehensive construction management and inspection services throughout the project. Their team of specialized Quality Assurance Representatives (QARs) oversaw the civil and electrical construction, ensuring adherence to contract specifications and safety standards. The Engineer-Procure-Construct (EPC) contract format and spatial limitations posed unique challenges, but MacKay Sposito’s diligent oversight contributed to the successful execution of the complex and schedule-driven upgrade.