Seneca Overview & Generator Rewind Asia-Pacific Partnership on Clean Development and Climate Seneca Overview & Generator Rewind Asia Pacific Partnership United States of America Power Generation Task Force August 13 – 17, 2007 Ron Kovach/Tom Groff

Seneca Overview Seneca: Generator Rewind 2

Seneca – View of Upper Reservoir 1/2 mi. dia. 60 ft deep 800 ft above plant asphalt lined Seneca: Generator Rewind 3

Seneca – View of Plant & Lower Reservoir Seneca: Generator Rewind 4

Seneca Plant Pumped Storage Facility 3 Units – Unit 1 218MW; Unit 2 195 MW; Unit 3 30 MW Role of Plant Provide generation, regulation and spinning reserve during on-peak hours Provide an energy sink off-peak (11 P.M. – 7 A.M.) to allow Fossil and Nuclear plants to remain more fully loaded (Base-Load Strategy) Black Start capability Seneca: Generator Rewind 5

Priorities Safety Environmental and Regulatory Compliance Reliability Federal Energy Regulatory Commission (FERC) Pennsylvania Department of Environmental Protection (PADEP) Reliability Cost effective operations Seneca: Generator Rewind 6

Staffing On-site staffing Corporate Support Other 6 Operators / 3 Maintenance 1 Administrative 2 Management Corporate Support Engineering Environmental Administrative IT Legal Other Contract labor services Seneca: Generator Rewind 7

View of Motor/Generator 1. Exciter 2. Upper Guide Bearing 3. Motor/Generator Rotor 4. Motor/Generator Stator 5. Thrust and Guide Bearing 6. Main Shaft Seneca: Generator Rewind 8

View of Pump/Turbine 9 9. Lower Guide Bearing 7. Wicket Gate Servomotor 8. Wicket Gate Operating Ring 10. Turbine Head Cover 17. Spherical Valve 12. Wicket Gate 11. Stay Ring 13. Runner 14. Spiral Case 15. Draft Tube Cone 16. Draft Tube Man Door Seneca: Generator Rewind 9

Typical Spherical Valve (also called High Head Guard Valve) Seneca: Generator Rewind 10

Equipment Suppliers Newport News Pump-turbines – Voith Runners L & S Governors Westinghouse motor – generators / National Electric coil rewinds Westinghouse voltage regulators BLH spherical valves ABB 230kv GCB’s Allis Chalmers 220MVA Step-up transformers Pascor Atlantic 230kv Phase reversal switches 400kva Emergency generator Seneca: Generator Rewind 11

Significant Projects Pump-Turbine Upgrades Motor-generator rewinds Unit No. 1 – 1992 Unit No. 2 – 1991 Motor-generator rewinds Unit No. 1 – 1971, 1985, 2006 Unit No. 2 – 1977, 1981, 2007 Unit No. 3 – original Upper Reservoir side slope paving – 2000 Seneca: Generator Rewind 12

Generating Operation 1 2 3 1 2 3 Upper Reservoir #1 218 MW #2 195 MW 21' diameter pipe, 3200' long 1 2 3 Motor/Generator Pump/Turbine 1 2 3 #3 generates to Allegheny River only #1 generates to Lower Reservoir only #2 can generate to Lower Res or river Seneca: Generator Rewind 13

Penstock Rendering Unit No. 1 – 218MW Unit No. 2 – 195MW Seneca: Generator Rewind 14

Pumping Operation 1 2 3 1 2 3 Upper Reservoir #1 220 MW #2 220 MW #3 Does not pump - used for starting #1 & #2 1 2 3 1 2 3 Units 1 & 2 draw water from the Lower Reservoir Seneca: Generator Rewind 15

Operation Upgraded Pump-Turbines – Efficiency Gain 3% Pumping 5 % Generating 700,000 + MWH Annual Generation Equivalent Forced Outage Rate (EFOR) < 2% High starting reliability 8 minute generate starts 30 minute pump starts Seneca: Generator Rewind 16

(Black Start Reserve) Seneca: Generator Rewind 17

Seneca: Generator Rewind 18

Generator Rewind Seneca: Generator Rewind 19

Decision to Rewind Last rewind occurred 20 years ago Tax Credit Upgrade (8MW) Extra copper – 7% Coil replacement End-of-life Proactive Partial Discharge (PD) / Corona Rotor Pole refurbishment Asbestos removal Seneca: Generator Rewind 20

Generator Rewind Unit #1 – Core Iron Continuous Restack Unit #2 – Core Repairs Loop test criteria max 10°C Hot Spots Repair techniques Thin mica sheets, between laminations Grind and electro-mechanical etching New Air Coolers - #1 & #2 Crane Engineered lift Seneca: Generator Rewind 21

Stator Lifting Beams Bolted to Stator Pinned to (2) crane hooks Stator weighs 232 tons Seneca: Generator Rewind 22

Stator Lift over Unit #3 Seneca: Generator Rewind 23

W Nameplate Info 336 Coils Seneca: Generator Rewind 24

Loop Test Cables 16x3 Turns 2400 Volts 300/Loop Amps Stator Iron in 3 Sections IR Camera to look for hot spots 10°C or less acceptance criteria Seneca: Generator Rewind 25

Coil Wedges Top view of slot wedges with ripple springs behind 26 Seneca: Generator Rewind 26

Brazing Brazing done using an Induction Machine 264 Series Joints 50 Jumper Joints 50 Phase Joints Seneca: Generator Rewind 27

( ) ( ) ( ) ( ) = 60hz Pole Keys 2 per Pole 225 RPM 32 Poles 225 Revolutions 1 Minute ( 1 Minute 60 Seconds ) ( 32 Poles 1 Revolution ) ( 1 Cycle 2 Poles ) ( ) = 60hz (Cycles/second) Seneca: Generator Rewind 28

Pole Shipment Fixture Bottom fixture rounded to allow horizontal placement Seneca: Generator Rewind 29

Thrust Bearing Shoes Thrust Bearing Shoes in place Oil supply hoses installed Seneca: Generator Rewind 30

Wear Pattern on Thrust Bearing Shoes Removed from Unit #1 Units No. 1 and No. 2 12 shoes each Unit No. 3 8 shoes Seneca: Generator Rewind 31