1. 5/17/2000Summer Preparedness 20001

2. 5/17/2000Summer Preparedness 20002 SRP SUMMER PREPAREDNESS 2000 Presented to the Arizona Corporation Commission May 17, 2000

3. 5/17/2000Summer Preparedness 20003 Dave Areghini Associate General Manager, Power, Construction and Engineering Services

4. 5/17/2000Summer Preparedness 20004 AGENDA b Summary of Year 2000 Projected Conditions and SRP Generating Plant Readiness b Resources and Reserves b SRP Transmission and Distribution System Readiness b Emergency Operations and Load Shedding

5. 5/17/2000Summer Preparedness 20005 SUMMARY OF YEAR 2000 PROJECTED CONDITIONS b Transmission is adequate to meet the forecasted peak load and reserves b SRP generation is ready and purchases are adequate to meet the forecasted year 2000 demand b Emergency plans are in place to handle contingency events

6. 5/17/2000Summer Preparedness 20006 John Coggins Manager Supply and Trading

7. 5/17/2000Summer Preparedness 20007 OPERATING RESERVES b Protect Against Loss of Generation or Transmission Resources Used to Deliver Energy to Firm Load b Targeted Reserve Levels Based on: Amount of Firm LoadAmount of Firm Load Largest Single HazardLargest Single Hazard

8. 5/17/2000Summer Preparedness 20008 SUMMER 2000 RESERVES Jun JulAugSep Load (MW)4871508450844696 Actual Reserves*624636624624 Reserves Inside Valley447209277624 Outside Valley1774273470 * Meets WSCC and NERC Criteria Meets Southwest Reserve Sharing Group Criteria Meets Southwest Reserve Sharing Group Criteria

9. 5/17/2000Summer Preparedness 20009 WW LB KY/SK MD NV PP FC/CR/HY CO SRP Distribution Territory Valley Reserves 209 MW Available Import Capability 0 MW ALL UNITS ON LINE - JULY PV Outside Valley Reserves 427 MW

10. 5/17/2000Summer Preparedness 200010 RESULT Peak Load Day (5084 MW) in July b Outside Valley Recovery –Full Recovery From Loss of Largest Generating Unit and and –Full Recovery From Loss of Unit Less Than 245 MW b Inside Valley Recovery –Full Recovery From Loss of Largest Generating Unit and and –Full Recovery From Loss of Unit Less Than 28 MW

11. 5/17/2000Summer Preparedness 200011 COORDINATING VALLEY UNIT COMMITMENT APSMerchantSRPMerchant SRPCAOAPSCAO

12. 5/17/2000Summer Preparedness 200012 GLEN CANYON LOW FLOW TESTING b Test Flows Implemented May - September Result of 1994 Biological Opinion by USF&WSResult of 1994 Biological Opinion by USF&WS Requires Low Steady Flow At 8,000 cfs June - SeptRequires Low Steady Flow At 8,000 cfs June - Sept b Reduces Plant Output by Several Hundred MW Impacts Market Pricing in the SWImpacts Market Pricing in the SW Impacts Exchange Arrangements with SRPImpacts Exchange Arrangements with SRP

13. 5/17/2000Summer Preparedness 200013 GLEN CANYON LOW FLOW TESTING b Emergency Exception Criteria In Effect Activation Requires System Wide EmergencyActivation Requires System Wide Emergency b Testing May Be Abandoned Due to Hydrology

14. 5/17/2000Summer Preparedness 200014 SRP TRANSMISSION AND DISTRIBUTION SYSTEM READINESS Dave Areghini

15. 5/17/2000Summer Preparedness 200015 SYSTEM IMPROVEMENTS b Items Increasing Import Capability Knox 230kV receiving station andKnox 230kV receiving station and 1-230/69 transformer Four 46 MVAR 69kV capacitor banks at Brandow,Four 46 MVAR 69kV capacitor banks at Brandow, Papago Buttes, White Tanks and Knox REKONDZI: Most of the items you have listed help the subtransmission system but I believe only Item 1 (Knox xfmr) & Item 2 (69kV caps) help the transmission system. The 69kV capacitors are the main reason the lower portion of the load serving nomogram has increased from last year. Item 4, SI/GF monitor did not provide any increase in capacity like the WW/AF monitor did. There are some significant maintenance replacement items, relay improvements, WSCC uniform off frequency load shedding, and 500/230 - 230/69 Transformer re-ratings that also contribute to increased load serving capability REKONDZI: Most of the items you have listed help the subtransmission system but I believe only Item 1 (Knox xfmr) & Item 2 (69kV caps) help the transmission system. The 69kV capacitors are the main reason the lower portion of the load serving nomogram has increased from last year. Item 4, SI/GF monitor did not provide any increase in capacity like the WW/AF monitor did. There are some significant maintenance replacement items, relay improvements, WSCC uniform off frequency load shedding, and 500/230 - 230/69 Transformer re-ratings that also contribute to increased load serving capability

16. 5/17/2000Summer Preparedness 200016 SYSTEM IMPROVEMENTS b Items Serving Increasing Distribution Load 2 nd Ward 230/69kV transformer2 nd Ward 230/69kV transformer Multiple line upgradesMultiple line upgrades REKONDZI: Most of the items you have listed help the subtransmission system but I believe only Item 1 (Knox xfmr) & Item 2 (69kV caps) help the transmission system. The 69kV capacitors are the main reason the lower portion of the load serving nomogram has increased from last year. Item 4, SI/GF monitor did not provide any increase in capacity like the WW/AF monitor did. There are some significant maintenance replacement items, relay improvements, WSCC uniform off frequency load shedding, and 500/230 - 230/69 Transformer re-ratings that also contribute to increased load serving capability REKONDZI: Most of the items you have listed help the subtransmission system but I believe only Item 1 (Knox xfmr) & Item 2 (69kV caps) help the transmission system. The 69kV capacitors are the main reason the lower portion of the load serving nomogram has increased from last year. Item 4, SI/GF monitor did not provide any increase in capacity like the WW/AF monitor did. There are some significant maintenance replacement items, relay improvements, WSCC uniform off frequency load shedding, and 500/230 - 230/69 Transformer re-ratings that also contribute to increased load serving capability

17. 5/17/2000Summer Preparedness 200017 Load Serving Capacity N-0 Continuous & Emergency Limit 5339 MW N-1 Continuous & Emergency Limit 5229 MW Forecasted Base Peak 4970 MW Forecasted Upper Peak 5084 MW

18. 5/17/2000Summer Preparedness 200018 SYSTEM PREPARATION Major Line PatrolsMajor Line Patrols Preventative MaintenancePreventative Maintenance Pole WorkPole Work Personnel TrainingPersonnel Training Tree Trimming Cable Replacement Storm Plan Summer Substation and Line Maintenance Complete

19. 5/17/2000Summer Preparedness 200019 EMERGENCY OPERATIONS AND LOAD SHEDDING b System Normal b Capacity Critical b Capacity Emergency b Pre-load Shedding b Rotating Blackouts

20. 5/17/2000Summer Preparedness 200020 CAPACITY CRITICAL b Potential for Operating Reserve Deficiency if a Major Resource is Lost b Warning Issued to All Plants

21. 5/17/2000Summer Preparedness 200021 CAPACITY EMERGENCY b Potential for loss of load if a major resource is lost (reserves are depleted) b Staff unmanned hydro units b Stop maintenance that could jeopardize unit availability

22. 5/17/2000Summer Preparedness 200022 CAPACITY EMERGENCY b Prepare to: Cut wholesale salesCut wholesale sales Utilize emergency generation, reduce auxiliary loadsUtilize emergency generation, reduce auxiliary loads

23. 5/17/2000Summer Preparedness 200023 ROTATING BLACKOUTS b Predetermined program has already protected critical loads such as hospitals b Load shedding program curtails delivery of power to retail customers

24. 5/17/2000Summer Preparedness 200024

25. 5/17/2000Summer Preparedness 200025 SUMMARY OF YEAR 2000 PROJECTED CONDITIONS b Transmission is adequate to meet the forecasted peak load and reserves b SRP generation is ready and purchases are adequate to meet the forecasted year 2000 demand b Emergency plans are in place to handle contingency events

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