Boundary Dam’s Unit 53 Generator is Back Online

Boundary Dam’s electrical generating unit 53 is back up and running for the peak generation season on the Pend Oreille River. The generator was repaired in half the time it typically takes for this type of project and $1 million under budget.

Boundary Dam’s electrical generating unit 53 is back up and running for the peak generation season on the Pend Oreille River. The generator was repaired in half the time it typically takes for this type of project and $1 million under budget.

Photo of the generators in the Boundary Dam powerhouse.

Unit 53 returned to service in the Boundary Dam powerhouse in time for the Pend Oreille River’s highest flows of the year.

On April 27, 2013, the generator experienced a severe electrical short disabling the unit right before peak generation, causing an estimated $6 million to $7 million loss in surplus power sales between April and July of 2013. Industry experts determined the unit needed a full replacement of the electrical windings in the generator core; this type of work is known as rewinding. Unit 53 was last rewound in 1982 and was scheduled for maintenance in 2017.

To uphold a commitment to serve City Light customers with low-cost, reliable power, crews, engineers and project managers prepared an emergency contract and work plan approved by General Manager and CEO Jorge Carrasco to bring Unit 53 back to service in time for the 2014 snowpack runoff.

Repair costs were estimated at $18 million and were paid from City Light’s capital improvement projects budget, having no effect on ratepayers.

Such projects typically take two years to complete. The dedicated project team worked diligently and strategically to complete overhaul Unit 53 in less than 12 months and $1 million under budget.

“The project is an example of how a completely focused team, with exceptional project management, can come together and rebuild a machine in half the time we would typically take,” Carrasco said.

Boundary Dam

Boundary Dam

Seattle City Light is the 10th largest public electric utility in the United States. It has some of the lowest cost customer rates of any urban utility, providing reliable, renewable and environmentally responsible power to about 750,000 Seattle area residents. City Light has been greenhouse gas neutral since 2005, the first electric utility in the nation to achieve that distinction.