Best in State:
Gold Award


Project: Lake Chelan hydro modernization
Client: Chelan County Public Utility District

Photo courtesy of MWH
MWH designed a modernization of the 85-year-old powerhouse at the Lake Chelan Hydroelectric Project.

Electrical power in Chelan County is provided by the Lake Chelan Hydroelectric Project, located approximately 32 miles north of Wenatchee, near the geographic center of Washington state.

The facility includes a 40-foot-high, 490-foot-long dam plus a large powerhouse that was built in 1927 and had become deteriorated and inefficient. MWH was brought in to conduct a comprehensive modernization of the powerhouse that included extending the life of the equipment, increasing efficiencies and eliminating the need for almost constant maintenance.

The project began with intensive computerized and physical modeling that was conducted at the generating equipment supplier’s hydraulic laboratories in Grenoble, France.

Replacing the original generator stators and refurbishing the generator rots, coupled with turbine improvements, resulted in significantly more energy production with no increase in water use. Installing modern digital controls provided automation and improved monitoring, which lowered the facility’s operation and maintenance costs.

The modernization also achieved significant environmental gains. The original low-pressure oil turbine operating system was replaced with a high-pressure system. The turbine guide bearing, which had been oil-lubricated, was changed to a water-lubricated bearing.

These changes reduced the amount of oil needed by the hydraulic turbines by a factor of 10, resulting in far less oil released into the environment through leakage or spills. Also, the turbine grease lubrication system was completely eliminated through the application of self-lubricating materials, eliminating any future grease contamination of water flowing into the Columbia River.

The modernization bumped the estimated service life of the facility up to 40 years, increased turbine peak efficiencies and eliminated constant maintenance. Additional revenue from the turbine performance essentially financed the entire modernization program.

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