The new exciters will replace obsolete equipment that is prone to frequent breakdowns often resulting in lost revenue and power generation. A one-week outage with only one generator is estimated to cost about $250,000, but if a second generator is also out-of-service the costs climb to nearly $800,000. Financial losses can ascend over four times as much in July when power demands are at their highest.

“Recently, one of the 800-MVA generators was forced out of service for several days by the failure of a small choke coil in the exciter regulator circuitry,” said David Murillo, Grand Coulee Power Manager. “Completing this project will keep our power system strong and dependable.”

ABB will furnish and install the six new digitally-controlled excitation systems complete with power potential transformers, power circuit breakers and other associated equipment, and also remove existing equipment. The project is scheduled for completion by January 2013.

Grand Coulee Dam, completed in 1942, provides about one-quarter of the total generation of the Federal Columbia River Power System. The dam’s generators produce approximately 20BkWh of electricity in an average water year, enough to supply more than 1 million homes. It is also a multipurpose facility providing water for irrigation, flood control, recreation, fish, and wildlife.

Funding for the project is coming from the Bonneville Power Administration which markets power generated from federal hydro power facilities in the Pacific Northwest.