Chelan PUD details 30 years of modernization at Columbia River dams

WENATCHEE — Chelan County PUD commissioners received a detailed look March 2 at more than three decades of modernization work at the utility’s hydropower projects, including upgrades aimed at improving efficiency and reliability at Rocky Reach and Rock Island dams.

The presentation was delivered by Brett Bickford, managing director of generation and transmission, and Maura Gillin, manager of generation asset management, during a commission study session.

“Today, we're going to review about 30 years of modernization activities that are hydro projects,” Bickford told commissioners.

The projects date back to the early 1990s, when Chelan PUD began modernizing generating units at Rocky Reach Dam. The work included turbine replacements, transformer upgrades and improvements designed to reduce maintenance outages while increasing power output.

Bickford said the original upgrades aimed to push generator performance to the highest levels possible.

“It was about the highest efficiency of any machines in the industry, but we think we pushed the limit a little too hard,” he said.

Some equipment installed during earlier modernization efforts did not last as long as expected. Bickford told commissioners that components designed for decades of service sometimes failed far sooner, forcing the utility to revisit earlier engineering decisions.

“When you modernize a unit, you think you might have in the utility industry maybe 40 or 50 years of life,” he said.

Instead, the district encountered turbine failures and insulation problems much earlier than anticipated, prompting a series of redesigns and replacements.

In several cases, Chelan PUD engineers developed solutions internally rather than relying solely on outside contractors.

“We were able to in-house engineer a fix for that, and then internally also perform all the repairs,” Bickford said.

Those efforts took about five years to complete and involved repairs across multiple powerhouse units.

Modernization work has also delivered measurable efficiency gains.

At Rock Island Powerhouse 1, Bickford said upgrades significantly improved turbine performance.

“We were able to get a whole 10 percent efficiency gain,” he said while describing new turbine designs installed at the facility.

Improved efficiency means the turbines can generate more electricity using the same amount of river water — a key advantage for a public utility operating under environmental and water-management constraints.

“So, we're getting more energy for less water,” Bickford told commissioners.

Chelan PUD operates three major hydropower facilities: Rocky Reach Dam, Rock Island Dam and the Lake Chelan project. Together, those facilities produce the vast majority of the utility’s electricity supply.

Commissioners asked several questions during the presentation about efficiency improvements and the additional energy output the upgrades make possible.

Bickford said the improvements allow the turbines to produce more electricity from the same river flow.

“So, it's like getting better gas mileage,” he said.

Andrew Simpson: 509-433-7626 or andrew@ward.media