Grant County PUD Plant Upgrades at Wanapum and Priest Rapids Dams Kevin Marshall, PE GC PUD Hydro Engineering Manager NWHA Conference February 18, 2014

Ongoing Upgrades for Wanapum Dam Turbine Replacement (Note: GCPUD took advantage of CREB bonds and a DOE design/development grant) Work is complete. Generator replacements New exciters Digital Governors Transformers

Reasons for Turbine Upgrades Original turbine runners had reached the end of their useful life Blade crack repairs Trunnion seal issues Operating linkage failures Cavitation repair costs - $75,000/unit/year (1987-1993 average costs) Performance improvements Improved fish passage survival

Wanapum Turbine Upgrades Design Features Semi to fully spherical Larger diameter: 20 inch increase Deeper setting : 3.315 feet deeper Performance Improvements Increased capacity: 120khp to 150khp Efficiency improvement: 3% average weighted efficiency Cavitation repair costs: $0

Reasons for Generator Upgrades Replace components at the end of their life. Capture increased output of new turbines

Wanapum Generator Upgrades New Parts Complete Rotor Complete Stator Generator Shaft Ventilation System Excitation System Air-Gap Monitoring Rotor spider arrives in 3 sections, stator frame in 4

Wanapum Governor/Unit Control Upgrades What Mechanical governors replaced with digital Dynamic exciters replaced with static exciter and digital controllers Why Spare parts no longer available Serviceman knowledge not transferred with retirements Improved control/efficiency Improved protection More info/better trouble shooting Lower costs to maintain

Existing Wanapum Mechanical Governors

New Wanapum Digital Governors

Current Wanapum Status 10th turbine, 4th generator, 4th exciter, and 3rd governor complete and put into service October 2013 5th generator, 5th exciter, and 4th governor under construction 10th generator and exciter to be completed in 2019 New turbines have a averaged, weighted efficiency gain of 3% As tested new generators have an increased efficiency from 98.0% to 98.5% 2 of 5 transformers replaced, 3rd transformer in process

Priest Rapids Dam Upgrades

Planned Upgrades for Priest Rapids Dam Turbine Replacement or life extension Generator rewinds New exciters Digital Governors Transformers already replaced

Reason for Upgrades Efficiency improvement Life Extension Aging equipment First unit in service in 1959 Generators Rotor pole problems including pole to pole connection failures (as pictured) Stator Winding age (oldest unit = currently 27 years old) Exciters are obsolete Turbines starting to exhibit problems Increased cycling of governor oil pumps Wicket gate operating ring wear

Turbine Upgrade Process Goals Utilize lessons learned from Wanapum project Obtain as many qualified bids as possible Competitive turbine hydraulic model testing Integrate biological considerations into design effort

Turbine Upgrade Process Step 1: Hydraulic design contract Professional Services Agreement Prequalification process – three contractors prequalified All design solutions finalized by contractors ahead of bidding All design solutions verified by independent hydraulic laboratory Step 2: Manufacture and supply contract Bidders must participate in hydraulic design contract to bid Performance guarantees verified prior to bidding

Status of Priest Rapids Upgrades Turbines Model testing was completed last week in Lausanne, Switzerland for the 3 qualified vendors Bids are due March 5th Contract award this summer (if economics are favorable) Generators: Pre-qualification of Vendors in process Controls: Governor specifications are in process Field work for upgrades is scheduled for 8/1/2016

Priest Rapids and Wanapum Upgrades QUESTIONS