A second hydroelectric turbine runner is on its way to Seattle City Light’s Boundary Dam in Pend Oreille County as part of a generator overhaul project that will increase Boundary’s generating capacity by 30 megawatts and reduce the dam’s impact on fish in the Pend Oreille River.
“This is a significant milestone for the work at Boundary and we look forward to receiving the new runner,” Power Production Director Mike Haynes said.
A turbine runner is the rotating part of a turbine that converts hydraulic energy in the form of moving water into mechanical energy, which is then turned into electricity by a generator. The turbine runner for Boundary is about 10 feet tall and 19 feet in diameter. It is being installed as part of a generator overhaul that will increase generating capacity at the dam to about 230 megawatts.
The new turbine runners also are designed to help reduce total dissolved gases in the water that comes through the dam, which is harmful to fish. The dam’s four other turbines were replaced in a six-year project that was completed in 2004.
City Light is investing about $60 million in the overhauls of Boundary’s two largest generators.
A special 20-axle semi tractor-trailer with escort cars is delivering the 181,000 pound turbine runner from Weir American Hydro’s plant in York, Pa. Along its 2,073 mile journey, it will travel through Maryland, West Virginia, Kentucky, Indiana, Illinois, Wisconsin, Minnesota, South Dakota, Wyoming, Montana and Idaho before arriving in Washington.
Weir American Hydro began the process of creating the Boundary turbine runners in February 2010. Turbine installations are performed by Seattle City Light crews and some contractors.
Generator rewinds, strator replacement and rotor refurbishment is being performed by Toshiba.
The overhaul and rehabilitation of the units is scheduled to be completed in May 2014.
Boundary Dam is responsible for about 60 percent of the electricity Seattle City Light generates on its own and about 30 percent of the electricity the utility’s customers use.