Grant County Public Utility District has awarded a $149.7 million contract to Alstom Hydro US Inc. to upgrade the ten generators at the 1,125-MW Wanapum Dam hydroelectric development, on the mid-Columbia River in Washington.
Grant County PUD commissioners approved a resolution Jan. 5 authorizing the district’s manager to enter into a contract with Alstom Hydro US, Littleton, Colo. The Federal Energy Regulatory Commission last year granted the utility’s proposal to upgrade generators at Wanapum, one of two developments in the 1,980-MW Priest Rapids project. (HNN 11/13/08)
Alstom submitted a winning bid for the work totaling $149,677,859. Two other companies �- Andritz Hydro, formerly VA Tech Hydro, and Voith Siemens Hydro Power Generation �- submitted bids in excess of the engineer’s $200 million estimate.
Devine Tarbell &Associates Inc. is providing professional engineering services for the generator upgrade program under a $1 million contract that extends through 2018.
FERC amended the Priest Rapids project license (No. 2114) in November 2008, increasing the total authorized capacity of the Wanapum and Priest Rapids developments to 1,980 MW from 1,893 MW. The new figure is based on 1,125 MW for Wanapum and 855 MW for Priest Rapids.
FERC previously amended the license to authorize installation of new advanced turbines rated at 112.5 MW. The new turbines are to increase total rated capacity to 1.5 million horsepower from 1.2 million hp, and increase the total hydraulic capacity to 188,000 cubic feet per second from 178,000 cfs.
Despite the turbine upgrade, the generators’ total nameplate capacity remained unchanged at 1,038 MW. However, each upgraded generator will have a nameplate rating of 122 MW. With the completion of all ten turbine replacements and the upgrade of the ten generators, the authorized capacity will be limited by the total turbine capacity of 1,125 MW.