APS/SRP 2 nd Quarter Stakeholder FERC Order 890 APS Attachment E SRP Attachment K APS Deer Valley Facility Phoenix, Arizona June 21, AM -12 PM

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

2. Status of Action Items There were no action items captured at the 4 th Quarter Stakeholder meeting held on 12/15/2015 3

3. Purpose of Today’s meeting Per APS’s OATT, APS conducts the 2 nd quarter public planning meeting to – A) review its current transmission study plan – B) provide an opportunity for transmission customers to update their loads, resources and other data that were submitted by September 1 – C) provide an opportunity for stakeholder input on any aspect of the study plan – D) review any stakeholder proposals previously submitted to APS for study plan alternatives – E) invite submittal of additional stakeholder study plan proposals for review and discussion – F) provide updates on APS’s planned transmission projects 4

3.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, 3 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 5

3.A. NERC Compliance Results? 2015 Results? – APS is fully compliant with NERC Transmission Planning Standards 2016 Progress? – SWAT case building complete – SWAT DYD files complete – SRP/APS interim case coordination started 6

3.A Ten-Year Plan Methodology Coordinated Base Cases – 2018HS – AZ coordinated case used to build heavy summer – 2021HS – AZ coordinated case used to build heavy summer – 2026HS –AZ coordinated case – 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 7 Note: AZ coordinated cases also included IID

3.A NERC Compliance Study Methodology NERC Compliance Studies Cases 2018 peak and off-peak cases 2021 peak case The long term and sensitivity cases have not been determined Following analyses are conducted: – Thermal and voltage – Short-Circuit – Transient Stability 8

3.B. 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 9

10

3.B. Feedback on the Plan? Feedback on the Plan or methodologies – NERC Reliability – Ten Year Plan See next slide to see how APS would evaluate plan submittals or alternatives. 11

12

3.B. Review Stakeholder proposals previously submitted APS received no stakeholder proposals in 2015 or prior to this meeting. 13

3.B. Submittal of additional study plan proposals If you have study ideas for APS to consider, please send a detailed message to: Please include (at a minimum) – Your Name/Company/contact info ( /phone #) – What the purpose of the study request is? And how will the results be used? E.g. Determine how much load the system can accommodate without new generation/transmission? Results will be used to inform developers where there may be opportunities for additional commercial development without transmission/generation investment. – What year(s) and season(s) is of interest? – What type of study – reliability (power flow only?) economic? 14

3.B. APS Ten-Year Plan Projects Transmission Plan Filed on Jan. 29,

In-Service: Hassayampa-North Gila 500kV #2 Line Bagdad 115kV Line Relocation 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 16

17 In-service: Palm Valley-Trilby Wash 230kV Line Sun Valley-Trilby Wash 230kV Line 2019: Ocotillo Modernization Project

18 In-service: Hassayampa-North Gila 500kV #2 Line 2021: North Gila-Orchard 230kV Line

3.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 – Palo Verde-Delaney-Sun Valley 500kV Energized May, 2016 – Sun Valley-Trilby Wash 230kV Energized May, 2016 Actively under construction – Mazatzal 345/69kV substation In-service date change – North Gila – Orchard 230kV project delayed from 2018 to

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 Transformer (in-service)2016 Delaney 500/69kV Transformer (in-service)2016 Mazatzal 345/69kV Transformer2017 Four Corners 500/345kV Transformer2017 North Gila 500/230kV Transformer2021 Orchard 230/69kV Transformer2021 Orchard 230/69kV Transformer #22021 Saguaro 230/69kV Transformer2021 Prescott 230/115kV Transformer #3TBD 20

3.C-E. APS Planning - Study Requests Interconnection Requests – Transmission Interconnection Requests – Generation Interconnection Requests Transmission Service Requests Economic Study Requests 21

3.C. Interconnection Requests 2 Active Wires-to-Wires Interconnection requests Active Generation Interconnection requests – APS OASIS contains Generation Interconnection Queue 12 Solar projects – MW 1 Wind projects – 200 MW 1 Wind/Solar project – 101 MW wind/60 MW solar 2 Natural Gas projects – 1229 MW 1 Battery Storage – 50 MW 2 PV Solar/Battery Storage – 423 MW Note: Generator Queue information as of 06/03/16 22

A – Hoodoo Wash 6 projects 1609 MW B - Gila Bend/Buckeye 3 projects 854 MW C – Metro Phx 2 projects 645 MW D – Saguaro Area 3 projects 458 MW E - Douglas 1 projects 17.5 MW F - Moenkopi 1 projects 161 MW G - Cholla 2 projects 275 MW H – Yuma Area 1 projects 70 MW I – Delaney 1 projects 70 MW Note 1: Generator Queue information as of 06/03/16 Note 2: Figures displayed may not represent complete queue A A B B C C F F D D 23 E E G G H H I I

3.D-E Transmission Service Requests and Economic Study Requests 37 Transmission Service Requests that may require a SIS Currently no Economic Study Requests 24

3.F. Submittal of additional study plan proposals If you have study ideas for APS to consider, please send a detailed message to: Please include (at a minimum) – Your Name/Company/contact info ( /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

SRP Stakeholder Meeting For Transmission Planning FERC Order 890 SRP Attachment K 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 26

4. Purpose of Today’s Meeting Per SRP’s OATT, SRP conducts the 2 nd quarter public planning meeting to: A)Review its current transmission study plan – provide an opportunity for transmission customers to update their loads, resources and other data – review any stakeholder proposals previously submitted to SRP for study plan alternatives B) Provide updates on SRP’s transmission projects (Ten Year Plan) C) Provide updates on the generation study requests D) Provide updates on the transmission study requests E) Provide updates on the economic study requests F) Invite stakeholders to submit additional study proposals 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 27

4.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 new TPL 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 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 28

4.A NERC Compliance Study Methodology Coordinated Base Cases (Seed Cases) 2018 – AZ coordinated case used to build – AZ coordinated case used to build – AZ coordinated case used to build 2026 The intermediate cases are APS/SRP coordinated – SRP NERC Compliance cases 2018, 2021, and kV transmission models incorporated Most up-to-date forecasts for peak summer loads 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 29

4.A NERC Compliance Study Methodology NERC Compliance Studies Cases 2018 Summer Peak & Sensitivity 2021 Summer Peak, Off-peak, & Sensitivity 2022 Summer Peak Case Following analyses are conducted: – Thermal analysis – Transient Stability – Short Circuit 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 30

4.A. NERC Compliance Studies NERC STANDARDType of Studies Completed TPL P0ThermalTransient StabilityShort Circuit 2018Peak, SensitivityXX 2021Peak, Off-peak, SensitivityXX 2022PeakXX TPL P1, P2ThermalTransient StabilityShort Circuit 2018Peak, SensitivityXXX 2021Peak, Off-peak, SensitivityXXX 2022PeakXXX 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 31

4.A. NERC Compliance Studies NERC STANDARDType of Studies Completed TPL P3-P7ThermalTransient Stability 2018Peak, SensitivityXX 2021Peak, Off-peak, SensitivityXX 2022PeakXX TPL Extreme EventsThermalTransient Stability 2018Peak, SensitivityXX 2021Peak, Off-peak, SensitivityXX 2022PeakXX 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 32

4.A. NERC Compliance Results 2015 Results – 2015 NERC Compliance Studies were finalized in December of /21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 33

4.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 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 34

6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 35

4.B. SRP Ten Year Plan SRP has filed its Ten Year Plan as of January 29 th, /21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 36

4.B 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 N-0 and N-1 Studies Conducted for all ten years 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 37

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) CEDAR MT (APS) ELDORADO MOHAVE 230kV PERKINS All Changes since January 2015 Ten Year Plan shown in red /21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 38

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 kV 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 To Silver King RS-28 (2018) 2018 TBD RS-27 (TBD) TO SANTA ROSA (APS) TO CASA GRANDE (APS) All Changes since January 2015 Ten Year Plan shown in red 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning Line Reconfiguration BALL TBD 39

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 TRANSFORMER All Changes since January 2015 Ten Year Plan shown in red 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning Reroute

4.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 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 41

4.B. SRP changes since 2015 Plan Revised In-Service Dates – Price Road Corridor was 2017-TBD, now 2018-TBD – Sun Zia was 2018, now 2021 – Eastern Mining Expansion was 2019, now TBD – 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 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 42

4.C. – 4.E. Transmission Planning Study Process SRP evaluates plan submittals or alternatives according to the following flowchart. 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 43

4.C.-E. SRP Planning - Study Requests Generation Interconnection Requests Transmission Interconnection Requests Transmission Service Requests Economic Study Requests 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 44

4.C. SRP Planning –Interconnection Requests (Transmission) Currently there are no Transmission Interconnection Requests under study 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 45

4.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 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning B A 46

4.D.-E. SRP - Transmission Service and Economic Study Requests SRP received two Transmission Service Requests There are no Economic Study Requests 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 47

4.F. Submittal of Additional Study Plan Proposals If you have study ideas for SRP to consider, please send a detailed message to: Please include (at a minimum): – Your Name/Company/contact info ( /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? 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 48

4.G. SRP Planning – Comments & Questions Stakeholder comments/questions on 2015 Study Results 6/21/2016 APS/SRP Stakeholder Meeting for Transmission Planning 49

5. Stakeholder Questions & Comments Open discussion Reference Material WestConnect – – APS OASIS – – SRP OASIS – –

6. Action Items Review any action items, assignments, and due dates 51