1. APS/SRP Stakeholder Meeting For Transmission Planning FERC Order 890 SRP Attachment K APS Attachment E SRP Facility – Scottsdale, AZ December 15 th, 2015 9:00 – 11:00 A.M. 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning 1

2. Agenda 1.Welcome, Introductions, and Stakeholder Meeting Overview 2.Status of Action Items – June 18, 2015 Joint APS/SRP 2 nd Quarter Public Planning Meeting 3.Purpose of Today’s Meeting – SRP Planning 4.Purpose of Today’s Meeting – APS Planning 5.Stakeholder Questions/Comments 6.Action Items Review 2 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

3. 2. Status of Action Items There were no Action Items from the Joint APS/SRP 2 nd Quarter Public Planning Meeting held on 6/18/2015 3 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

4. 3. Purpose of Today’s Meeting Per SRP’s OATT, SRP conducts the 4 th quarter public planning meeting to: – Review its current transmission study plan – Present a draft of its Ten Year Transmission Plan for the following calendar year for stakeholder review and comments – Review economic planning study request submitted by October 31 4 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

5. 3.A. – SRP’s Study Plan SRP has two distinct, but related, transmission study plans – NERC Compliance – SRP’s budgetary planning The difference between the two plans: – NERC Compliance studies based on old TPL-001 – TPL-004 Standards: 3 seasons/scenarios, 2 discrete years (near and long term) – NERC Compliance studies based on new TPL-001-4 Standard: 2 seasons/scenarios, 3 discrete years (near and long term) – SRP’s annual planning: 1 season, 10 consecutive years (first 6 years are for budget, remaining 4 for compliance purposes) The similarities between the two plans: – Similar load forecasts, demand response – They are reliability studies 5 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

6. 3.A. 2015 NERC Compliance Study Methodology Coordinated Base Cases (Seed Cases) 2016 – AZ coordinated case used to build 2016-2019 2020 – AZ coordinated case used to build 2020-2023 2024 – AZ coordinated case used to build 2024-2025 The intermediate cases are APS/SRP coordinated – SRP NERC Compliance cases 2017 and 2021 69kV transmission models incorporated Most up-to-date forecasts for peak summer loads 6 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

7. 3.A. 2015 NERC Compliance Study Methodology NERC Compliance Studies Cases 2017 & 2021 Summer Peak & Off-peak Cases and 2020 Summer Peak Case 2017 & 2021 Off-peak Cases are Low Load (winter conditions) and High Import (shoulder cases with low generation in the Phoenix Metro Area) Following analyses are conducted: – Thermal analysis – Post-Transient – Transient Stability – Short Circuit 7 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

8. 3.A. NERC Compliance Studies NERC STANDARDType of Studies Completed TPL-001 (N-0) and TPL-001-4 P0ThermalTransient StabilityPost-transientShort Circuit 2017Peak, Low Load and High ImportXX 2020PeakXX 2021Peak, Low Load and High ImportXX TPL-002 (N-1) and TPL-001-4 P1, P2ThermalTransient StabilityPost-transientShort Circuit 2017Peak, Low Load and High ImportXXXX 2020PeakXXXX 2021Peak, Low Load and High ImportXXXX 8 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

9. 3.A. NERC Compliance Studies NERC STANDARDType of Studies Completed TPL-003 (N-2) and TPL-001-4 P3-P7ThermalTransient StabilityPost-transient 2017Peak, Low Load and High ImportXXX 2020PeakXXX 2021Peak, Low Load and High ImportXXX TPL-004 (N-X) and TPL-001-4 Extreme EventsThermalTransient StabilityPost-transient 2017PeakXX 2020PeakXX 2021PeakXX 9 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

10. 3.A. NERC Compliance Results 2015 Results – 2015 NERC Compliance Studies were finalized by beginning of December of 2015 10 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

11. 3.A. – Customer Load/Resource Updates No customers provided load/resource data in September 2015 SRP received no stakeholder proposals in 2015 or prior to this meeting. If you like to provide information for the future SRP planning cycles, please see critical dates on the next slide 11 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

12. 12 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

13. 3.B. SRP Ten Year Plan 2016-2025 Draft - Still subject to change until January 31 st filing 13 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

14. 3.B. 2016-2025 Ten Year Plan Methodology Coordinated Base Cases – See NERC Compliance Methodology slide #6 69kV transmission models incorporated Most up-to-date forecasts for peak summer loads TPL-001 & TPL-002 Studies Conducted for all ten years 14 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

15. EXISTING LINES FUTURE LINES FUTURE 500kV SUBSTATION EXISTING 500kV SUBSTATION NEVADA WESTWING KYRENE SILVER KING CORONADO CHOLLA (APS) MEAD McCULLOUGH MARKETPLACE BROWNING HASSAYAMPA RUDD PALO VERDE PINAL WEST JOJOBA DUKE NAVAJO GS SUGARLOAF MOENKOPI (APS) YAVAPAI (APS) PINNACLE PEAK (APS) PINAL CENTRAL SUNZIA (SWPG) 2021 Central New Mexico SPRINGERVILLE (TEP) DUGAS (APS) 500kV System 345kV MORGAN (APS) 2016-2025 CEDAR MT (APS) TEP ELDORADO MOHAVE 230kV PERKINS All Changes since January 2015 Ten Year Plan shown in red 2024 15 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

16. Price Road Corridor Project BRANDOW WARD CORBELL ALEXANDER WESTWING KYRENE ANDERSON WHITE TANKS ORME SRP PINNACLE PEAK PAPAGO LIBERTY (W.A.P.A.) AGUA FRIA DEER VALLEY (APS) ROGERS TO APS OCOTILLO TO APS PINNACLE PEAK TO W.A.P.A. PINNACLE PEAK W.A.P.A. KNOX SCHRADER RUDD 2020 230kV System SANTAN THUNDERSTONE BROWNING EXISTING 230kV SUBSTATIONS FUTURE 230kV CIRCUIT EXISTING 230kV CIRCUIT FUTURE 230kV SUBSTATIONS GENERATING STATION DOUBLE CIRCUIT, PHASE TIED LINE GOLDFIELD ABEL DINOSAUR 2021 DESERT BASIN PINAL CENTRAL RANDOLPH 2021 PFISTER TBD 2016-2025 To Silver King RS-28 (2017) 2017 TBD RS-27 (TBD) TO SANTA ROSA (APS) TO CASA GRANDE (APS) All Changes since January 2015 Ten Year Plan shown in red 16 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning Line Reconfiguration BALL TBD

17. 115kV MIAMI PINAL SUPERIOR SPURLOCK MOONSHINE ELLISON FRAZIER RAY MORRIS KEARNY HAYDEN STEWART MOUNTAIN MORMON FLAT HORSE MESA GOLDFIELD 230kV OAK FLAT PINTO VALLEY KNOLL TO APACHE (AEPCO) TO THUNDERSTONE COOLIDGE (W.A.P.A.) TO SILVER KING 500kV SILVER KING 230 ASARCO GENERATING STATION EXISTING LINE FUTURE LINE EXISTING SUBSTATION FUTURE SUBSTATION Eastern Mining Area CARREL BONNEYBROOK (APS) TRASK CARLOTA ROOSEVELT 2016-2025 TRANSFORMER All Changes since January 2015 Ten Year Plan shown in red 17 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning Reroute 2017

18. 3.B. SRP changes since 2015 Plan Completed Projects – Browning - Rogers 230kV line New Projects – None Removed Projects – Hassayampa – Pinal West 500kV Jojoba Loop-in Removed from SRP’s plan since TEP is the driver of this project 18 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

19. 3.B. SRP changes since 2015 Plan Delayed Projects – Eastern Mining Expansion was 2019, now TBD – Sun Zia was 2018, now 2021 – Silver King-RS29 230kV was 2019, now TBD – RS29 230kV substation was 2019, now TBD – RS29-RS30 115kV was 2019, now TBD – RS30 115kV substation was 2019, now TBD 19 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

20. 3.C. – 3.E. Transmission Planning Study Process SRP evaluates plan submittals or alternatives according to the following flowchart. 20 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

21. 3.C.-E. SRP Planning - Study Requests Generation Interconnection Requests Transmission Interconnection Requests Transmission Service Requests Economic Study Requests 21 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

22. 3.C. SRP Planning –Interconnection Requests (Transmission) Currently there are no Transmission Interconnection Requests under study 22 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

23. 3.C. Interconnection Requests (Generation) A. EAST VALLEY 2- Solar Projects 98MW B. EMA 115kV AREA 2- Solar Projects 60MW Generation Interconnection Requests listed on this slide are for SRP solely owned transmission 23 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning B A

24. 3.D.-E. SRP - Transmission Service and Economic Study Requests SRP received two Transmission Service Requests There are no Economic Study Requests 24 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

25. 3.F. Submittal of Additional Study Plan Proposals If you have study ideas for SRP to consider, please send a detailed message to: SRP.TransmissionPlanning@srpnet.com SRP.TransmissionPlanning@srpnet.com Please include (at a minimum): – Your Name/Company/contact info (e-mail/phone #) – What the purpose of the study request is? And how will the results be used? – What year(s) and season(s) is of interest? – What type of study – reliability (power flow only?), economic? 25 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

26. 3.G. SRP Planning – Comments & Questions Stakeholder comments/questions on 2015 Study Results 26 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

27. APS 4th Quarter Stakeholder FERC Order 890 APS Attachment E

28. 4.A. APS’s Study Plan APS has two distinct, but related, transmission study processes – NERC Compliance – APS’s Annual Planning The difference between the two plans: – NERC Compliance: Minimum 2 seasons, 2 discrete years (near and long term); all cases examine P0-P7 (formerly Category A – D) – APS’s annual planning: 1 season, 10 consecutive years; N-0 and N-1 – NERC Compliance is now starting point for annual plan Working on combining TPL assessment and Annual Planning for future years – TPL assessment results utilized for 10yr plan – 10Yr plan fills in the gap years 28

29. 4.A. NERC Compliance Results? 2014 Results? – APS is fully compliant with NERC Transmission Planning Standards 2015 Progress? – Case building complete – DYD files complete – Study work being finalized – Report writing started 29

30. 4.A. 2015 NERC Compliance Study Methodology NERC Compliance Studies Cases 2016, 2020 & 2024 Summer Peak Cases – Sensitivity case has higher import, and lower metro internal generation Off-peak Case is Low Load and High Import (shoulder case with low generation in the Phoenix Metro Area) – 2017 Light Spring case; one case in the near-term – High ratio of renewable generation to overall generation on-line – Sensitivity case is higher export, more internal metro generation on-line Following analyses are conducted: – Thermal and voltage – Short-Circuit – Transient Stability 30

31. 4.A. 2015 NERC Compliance Studies TPL-001-4 combined previous TPL-001 through TPL-004 – No longer Category A, B, C, & D – Now P0 through P7 Covers all scenarios from N-0 to N-1-1 Also includes Multiple Contingencies due to relay or breaker failures – Requires more cases/scenarios – Includes short-circuit analysis (2024) 31

32. 4.A. APS TPL Plan for 2015 Study Near-TermLong-Term Year1 (2016) 2 (2017) 345 (2020) 6789 (2024) 10 Steady State Peak Load (Summer)XXX Peak load sensitivityXX Off-Peak (Spring)X Off-Peak sensitivityX Stability Peak Load (Summer)X Peak load sensitivityX Off-Peak (Spring)X Off-Peak sensitivityX 32

33. 4.A. 2016-2025 Ten-Year Plan Methodology Coordinated Base Cases – 2015HS – SASG/AZ coordinated case used to build heavy summer 2016-2019 – 2020HS – AZ coordinated case used to build heavy summer 2021-2023 – 2024HS – SWAT/AZ coordinated case used to build heavy summer 2025 (same SWAT updated case submitted to WestConnect) – The intermediate cases are APS/SRP coordinated 69kV transmission models incorporated Most up-to-date forecasts for peak summer loads N-0 and N-1 analysis conducted for all ten years 33 Note: AZ coordinated cases also included IID

34. 4.A. 2016-2025 Ten-Year Plan Status AZ Seed cases are complete (2016HS, 2020HS, 2024HS) Intermediate cases are complete Ten-Year plan studies are being finalized Ten-Year Plan filed by the end of January BTA Studies will also be completed and filed – 10 th Year Snapshot & Extreme Contingency – RMR study – no triggers were identified for PHX/Yuma 34

35. 4.A. Customer Load/Resource Updates APS has all load/resource data from Network Customers and has incorporated them into the base cases APS received no stakeholder proposals in 2015 orprior to this meeting Should you like to provide information for the future APS planning cycles, please see critical dates on the next slide 35

36. 36

37. 4.B. APS Ten-Year Plan Projects 2015- 2024 Transmission Plan Filed on Jan. 30, 2015 (updated with 2015 activities) 37

38. 4.B. Changes since 2015 Plan was filed Three projects completed – Bagdad 115kV Relocation – Hassayampa-North Gila #2 500kV line Energized May, 2015 New Path 49 (EOR) rating of 10,100 MW – Palm Valley-Trilby Wash 230kV line Energized April, 2015 Trilby Wash now providing new source for northwestern part of valley Actively under construction – Palo Verde-Delaney-Sun Valley 500kV – Sun Valley-Trilby Wash 230kV – Mazatzal 345/69kV substation In-service date change – Ocotillo Modernization Project in-service pushed back to 2019 38

39. In-Service: Hassayampa-North Gila 500kV #2 Line Bagdad 115kV Line Relocation 2016: Delaney-Palo Verde 500kV Line Delaney-Sun Valley 500kV Line 2017: Mazatzal 345/69kV Substation 2018: Morgan-Sun Valley 500kV Line 2019: Ocotillo Modernization Project 39

40. 40 In-service: Palm Valley-Trilby Wash 230kV Line 2016: Sun Valley-Trilby Wash 230kV Line 2019: Ocotillo Modernization Project 2026: Morgan-Sun Valley 230kV Line

41. 41 In-service: Hassayampa-North Gila 500kV #2 Line 2018: North Gila-Orchard 230kV Line

42. Bulk Transformer Additions/Replacements DescriptionYear Two 100MVAR Reactors at Four Corners 230kV (in-service)2015 Trilby Wash 230/69kV Transformer (in-service)2015 Sun Valley 500/230kV Transformer2016 Delaney 500/69kV Transformer2016 Mazatzal 345/69kV Transformer2017 North Gila 500/230kV Transformer2018 Orchard 230/69kV Transformer2018 Orchard 230/69kV Transformer #22018 Saguaro 230/69kV Transformer2021 Prescott 230/115kV Transformer #3TBD 42

43. 4.C-E. APS Planning - Study Requests Interconnection Requests – Transmission Interconnection Requests – Generation Interconnection Requests Transmission Service Requests Economic Study Requests 43

44. 4.C. Interconnection Requests 2 Active Wires-to-Wires Interconnection requests Active Generation Interconnection requests – APS OASIS contains Generation Interconnection Queue http://www.oatioasis.com/azps/index.html 5 Solar projects – 787.5 MW 1 Wind projects - 200 MW 1 Wind/Solar project – 101 MW wind/60 MW solar 2 Natural Gas projects – 919 MW 1 Battery Storage – 74 MW Note: Generator Queue information as of 10/16/15 44

45. A - HAA-NG 500kV line 2 projects 700 MW B - Gila Bend/Buckeye 2 projects 654 MW C – Metro Phx 2 projects 669 MW D - Saguaro 1 projects 50 MW E - Douglas 1 projects 17.5 MW F - Moenkopi 1 projects 161 MW G - Cholla 1 projects 200 MW Note 1: Generator Queue information as of 10/16/15 Note 2: Figures displayed may not represent complete queue A A B B C C F F D D 45 E E G G

46. 4.D-E Transmission Service Requests and Economic Study Requests 42 Transmission Service Requests that may require a SIS Currently no Economic Study Requests 46

47. 4.F. Submittal of additional study plan proposals If you have study ideas for APS to consider, please send a detailed message to: apstransmission@aps.com apstransmission@aps.com Please include (at a minimum) – Your Name/Company/contact info (e-mail/phone #) – What the purpose of the study request is? And how will the results be used? – What year(s) and season(s) is of interest? – What type of study – reliability (power flow only?) economic? 47

48. 5. Stakeholder Questions & Comments Open discussion Reference Material WestConnect – – http://www.westconnect.com/documents.php http://www.westconnect.com/documents.php APS OASIS – – http://www.oatioasis.com/azps/index.html http://www.oatioasis.com/azps/index.html SRP OASIS – – http://www.oatioasis.com/srp/index.html http://www.oatioasis.com/srp/index.html 48 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning

49. 6. Action Items Review any action items, assignments, and due dates 49 12/15/2015 APS/SRP Stakeholder Meeting for Transmission Planning