Four Corners 230kV Generator Interconnections Group

Transcription

1 A subsidiary of Pinnacle West Capital Corporation Four Corners kv Generator Interconnections Group Feasibility Study APS Contract Nos. - By Arizona Public Service Company Transmission Planning September, Revision Prepared by Utility System Efficiencies, Inc.

2 FOUR CORNERS kv GENERATOR INTERCONNECTIONS GROUP FEASIBILITY STUDY Table of Contents Executive Summary... Study Assumptions.... Pre-Project Base Cases.... Post-Project Base Cases... Study Methodology.... Power Flow Analysis.... Short Circuit Analysis.... Network Capability Criteria.... Power Factor Evaluation... Study Results.... Power Flow.... Short Circuit.... Network Capability Analysis.... Mitigation.... Power Factor Evaluation... Cost and Construction Schedule Estimates... Appendix Power Flow Diagrams Appendix Contingency Matrix Appendix Minimum Arizona, Southern Nevada, Southern California, Northern New Mexico and Southern Utah Bus Voltage Limits & WECC Transient Stability and Post Transient Voltage Criteria

3 Four Corners kv Generator Interconnections Q- Executive Summary Arizona Public Service ( APS ) has retained Utility System Efficiencies, Inc. ( USE ) to perform a generation Feasibility Study ( FeS ) for an Applicant s six proposed solar photovoltaic generation projects ( Project ). The six projects are to be studied in a single group FeS. The Applicant is planning development of two MW, three MW and one MW solar generation plants, with expected commercial operation dates between June and June. The Applicant has requested all the projects be interconnected into the Four Corners kv switchyard, and that the projects be studied as a Network Resource with APS as the purchaser. The Four Corners kv switchyard is an APS owned switchyard with others owning some of the interconnection facilities. It is also an integral part of the jointly owned Four Corners power plant which is a jointly owned facility. As such, the requested interconnections will coordinate with the Four Corners Transmission Engineering and Operating Committee ( E&O Committee ) which is being established. Further interconnection studies, including the System Impact Study, would be conducted with the input from and to the satisfaction of the Four Corners Technical Studies Task Force (FCTSTF). DISCLAIMER Nothing in this report constitutes an offer of transmission service or confers upon the Interconnection Customer ("IC"), any right to receive transmission service. APS and other interconnected utilities may not have the Available Transmission Capacity (ATC) to support the interconnection described in this report. It should also be noted that the results in this FeS are dependent upon the assumed topology and timing of new projects in the vicinity of the interconnection, which are subject to change. Figure. illustrates the proposed interconnections and the nearby transmission system. Figure. Proposed Solar Generation (Q - Q) and Nearby Transmission Facilities PINTO SAN JUAN WEST MESA MOENKOPI FOUR CORNERS kv kv kv McKINLEY Q-Q New Solar ( MW) kv kv kv SUGARLOAF SPRINGERVILLE PREACHER CANYON kv kv kv MAZATZAL (to SILVER KING) (to TEP) PINNACLE PEAK (to SAGUARO) Page

4 Four Corners kv Generator Interconnections Q- Analyses consisted of computer-based power flow analysis using post-transient governor power flow techniques and short circuit/fault duty analysis. The study modeled the proposed generation interconnections under Heavy Summer Peak conditions, both with and without the Four Corners Units, & generating units. The pre-project case with the existing Four Corners generation stressed the Southwest of Four Corners Path (Path ). The Project was then added to assess the impacts on Path, with generation dispatch scenarios to Arizona and to California. RESULTS: Four Corners Units, & on The pre-project case had a heavily stressed Path. Adding the Project ( MW) to the Four Corners kv bus, whether dispatched to Arizona or California, resulted in Path flows of MW (AZ) and MW (CA), well above nominal and inside the trip region of the path rating nomogram. With this stressed scenario, reducing the Project output to MW reduced the Path flows below nominal, but still on the edge of the nomogram. These results indicate the Project would have restrictions placed upon it as to when and how much it could generate and remain within the nomogram limitations. The results indicate the Project triggered four N- overloads. Four Corners / kv transformer - for loss of other Four Corners / kv transformer Glen Canyon / KV transformer # - for loss of Four Corners-Moenkopi kv line Glen Canyon / kv transformer # - for loss of Four Corners-Moenkopi kv line Glen PS Glen Canyon kv line - for loss of Four Corners-Moenkopi kv line The results also show the Project triggered three N- overloads and increased the loading of a fourth element from % to ~ %. Cholla - Mazatzal kv - for loss of Cholla-Saguaro and Coronado-Silverking kv Pinnacle Peak - Mazatzal kv - for loss of Cholla-Saguaro and Coronado-Silverking kv Ciniza - Pegs kv - for loss of San Juan - McKinley #& kv Ciniza - Wingate kv - for loss of San Juan - McKinley #& kv Remedial Action Schemes (RAS) will be required to trip the necessary Project generation for the above N- and N- outages. Voltage Deviation: The results of the governor power flow analysis indicate the Project did not trigger any voltage deviation violations. Four Corners Units, & off The results show the Project did not trigger any N- overloads, but did trigger one N- overload. A RAS will be required to trip the necessary Project generation in the event of this outage. Cholla - Mazatzal kv line - for loss of Cholla-Saguaro and Coronado-Silverking kv Voltage Deviation The results of the governor power flow analysis indicate the Project did not trigger any voltage deviation violations. Page

5 Four Corners kv Generator Interconnections Q- Short Circuit Analysis No equipment short circuit ratings in the vicinity of the project were exceeded as a result of the project. Study results indicate there are no circuit breaker fault duty limit violations attributable to the project. Network Transmission Capacity At the time of this study, APS had no available transmission capacity from the Four Corners substations for Network Transmission service. Even under the announced, but not approved, APS plan to shut down Four Corners units,, and ; acquire additional ownership in Four Corners units and ; and reacquire the rights on the Four Corners-Moenkopi kv line, there is no ATC. At the time of this study, there is a substantial queue for the additional capacity on the Four Corners-Moenkopi line that exceed the capacity of that line. To be able to accommodate Q- projects as Network Resources, substantial new transmission would need to be built. A new line from the Four Corners area to the Phoenix area would be extremely expensive, somewhere in the ballpark of $ billion. Power Factor The APS Open Access Transmission Tariff (OATT) requires Interconnection Customers to be able to achieve +/-. power factor at the POI, with the maximum "full-output" VAr capability available at all MW level outputs. Furthermore, APS requires Interconnection Customers to have dynamic voltage control and maintain the voltage as specified by the transmission operator within the limitation of +/-. power factor, as long as the Project is online and generating. The MVAR capacity requirements at the POI for a MW plant is MVAR, for a MW plant is MVAR and for a MW plant is MVAR. These MVAR values are net values after the projects have met the losses on the project s facilities. Project Costs and Construction The projected Network Upgrades for the Project consist of expansion of and some relocation work on the Four Corners kv switchyard and some Remedial Action Scheme (RAS) development work for tripping the Project off line for several N- and N- contingencies and for times when the system performance moves into the unit tripping region of the Four Corners Path nomogram. The estimated costs for the Network Upgrades are $,. Timing for the earlier in service date of June, can possibly be a problem if the System Impact Study, Facility Study and Large Generator Interconnection Agreement aren t completed by the end of. Four termination locations in the kv switchyard are available with the proposed expansion. This will accommodate three direct interconnections and one interconnection that connects to a kv gathering switchyard outside the Four Corners property and is to be built, owned and operated by the Project. The costs for the Transmission Provider s Interconnection Facilities associated with these four terminations and the line exits are estimated to be $,,. No cost estimates are made for the generator interconnection tie lines or the kv gathering switchyard. Timing for the earlier in service date of June, can t be achieved with a construction lead time of over one year and the System Impact Study, Facility Study and Large Generator Interconnection Agreement still needing to be completed before construction can begin. Page

6 Four Corners kv Generator Interconnections Q- Study Assumptions This section of the report provides details pertaining to the power flow case development and an overview of the major study assumptions. All power flow and post-transient work was completed using General Electric's Positive Sequence Load Flow (GE-PSLF), version... Pre-Project Base Cases The Heavy Summer case was developed from the WECC power flow case HSA, approved by WECC in early. Significant topology assumptions are shown below. The case was adjusted to achieve a high Path flow. Table.: Significant Topology Assumptions, Heavy Summer Case In-Svc. Project Date Included? Navajo Trans. Project kv Line (DREP/FCW, Red Mesa) N/A No Delany kv Substation Yes Sun Valley / kv Substation Yes Sun Valley Delany Palo Verde kv Line Yes Mazatzal Substation (Cholla-Pinnacle Peak kv Line) Yes Pinal West-Browning kv project Yes SunZia kv project - No Pinal Central-Tortolita kv Yes Generation Springerville Unit ( MW) Yes Desert Rock Energy Project ( MW) withdrawn No APS Q Cedar Mtn. Generator ( MW) Yes APS Q Moenkopi Generator ( MW) No APS Q - Moenkopi Generator ( MW) No APS proposed removal of Four Corners units, & No* APS & SRP queued generation projects near Cholla and Coronado - No * Sensitivity case will be run with the Project. A Sensitivity Case was developed from the Heavy Summer case to model the scenario of the Four Corners Units,, & removed from service. The units were turned off and dispatch was adjusted in the Palo Verde Hub to compensate.. Post-Project Base Cases The Post-Project cases were developed by adding the proposed Project and scheduling to: Arizona (APS) to the extent possible without exceeding established WECC operating limits. To accommodate the Project output, local generation was displaced within the modeled zone for APS. This scheduling was applied to both Pre-Project cases. California (CAISO) to the extent possible without exceeding established WECC operating limits. To accommodate the Project output, local generation was displaced within the modeled zone. This scheduling was only applied to the Heavy Summer Pre-Project case. Page

7 Four Corners kv Generator Interconnections Q- Project Assumptions/Modeling The Project consists of MW of solar photovoltaic generation, comprised of six separate projects. Two of the projects are MW, three are MW and one is MW. The generating units of each separate project will be connected together through a. kv collector system, and stepped up to kv. There will be six kv generator tie-lines, one for each project, varying in length from - miles long. The Project was studied with six separate gen-ties into the Four Corners kv bus. However, since there are only four available bays in the kv switchyard, an adjacent kv switchyard will likely be required for a collector switchyard. Subsequent studies should update the Project model with the latest information. Each project's equivalent model included a ACSR kv gen-tie, a /. kv transformer, a./. kv transformer, and an equivalent generator modeled with a fixed. lagging pf. The. kv collector systems were not modeled. Four Corners kv kv Gen-tie miles kv Gen-tie miles kv Gen-tie miles kv Gen-tie miles kv Gen-tie miles kv Gen-tie miles. kv MVA /. kv Z = %. kv MVA /. kv Z =.%. kv MVA /. kv Z =.%. kv MVA /. kv Z =.%. kv MVA /. kv Z =.%. kv MVA /. kv Z =.%. kv MVA./. kv Z = %. kv MVA./. kv Z = %. kv MVA./. kv Z = %. kv MVA./. kv Z = %. kv MVA./. kv Z = %. kv MVA./. kv Z = % MW pf =. lagging MW pf =. lagging MW pf =. lagging MW pf =. lagging MW pf =. lagging MW pf =. lagging Figure.: Four Corners kv New Generator Interconnections Additional inverter information will be required for the System Impact Study Page

8 Four Corners kv Generator Interconnections Q- Case Attributes A summary of case attributes is shown in the table below. Table.: Project Power Flow Case Attributes (MW) Heavy Summer Case No FC,& Case Base Case Path SW of Four Corners Path A kv Path B kv Pre- Project Post-Project Pre- Project Post- Project "AZ" "CAISO" "AZ" Area Arizona Generation,,,,, Load,,,,, Net Interchange Loss Area New Mexico Generation Load Net Interchange Loss Area SoCal Generation,,,,, Load,,,,, Net Interchange Loss Area PG&E Generation,,,,, Load,,,,, Net Interchange Loss Page

9 Four Corners kv Generator Interconnections Q- Study Methodology This Feasibility Study consists of power flow analysis using post-transient governor power flow techniques and short circuit analysis in order to identify a preliminary list of facilities needing upgrades, replacements or additions. A non-binding good faith estimate of cost responsibility and a non-binding good faith estimated time to construct facilities necessary to interconnect the projects in the group was determined.. Power Flow Analysis Power flow analysis was performed using the NERC/WECC planning standards. Power flow analysis was used to evaluate thermal and voltage performance of the transmission system for NERC/WECC Category A normal (all elements in-service) conditions, selected NERC/WECC Category B emergency (one element out of service) conditions and selected NERC/WECC Category C emergency (multiple elements out of service) conditions. Category A (N-) normal overloads are those that exceed % of normal ratings that occur with all facilities in service. Category B and C emergency overloads are those that exceed % of emergency ratings that occur due to a Category B or C contingency. All power flow analysis was conducted with version._ of General Electric s PSLF software. a) Normal Conditions ( N- ) i. All transmission facility loadings must be below normal continuous ratings. ii. Unless otherwise specified, transmission bus voltages must be maintained between. per unit and. per unit. iii. Post-Project bus voltage deviation from the Pre-Project base case shall not exceed established operating limits (see following monitored buses). Monitored Bus Voltages: Pinnacle Peak kv: Kyrene kv: Shiprock kv: % deviations from base case. % deviations from base case. % deviations from base case. iv. Sufficient transmission capacity will be provided without relying on or unduly imposing upon any other utility s transmission system. v. The transmission system will not result in an adverse impact on other major WECC path flow limits. b) Single Contingency Outage Conditions ( N- ) i. For a single contingency, no transmission element will be loaded above its emergency rating. ii. iii. iv. Established loading limits for other utilities will be observed. Equipment emergency voltage limits (high or low) will not be exceeded for single contingency outages. In general, transmission bus voltages must be maintained between. per unit and. per unit. Bus voltage deviations from the base case voltage shall not exceed established planning limits (these limits may vary throughout the system). In general, voltage deviations at any bus for N- contingencies must be no more than %. See Appendix for further specific bus voltage limitations. v. Single contingency outages on the kv and EHV systems will not result in loss of load. Page

10 Four Corners kv Generator Interconnections Q- A table showing minimum voltage limits for the critical buses in Arizona, Southern Nevada, Southern California, Northern New Mexico and Southern Utah is provided in Appendix. c) Double Contingency ( N- ) and Credible Multiple Element Outages Appendix identifies selected N-/Multiple Element outages to be studied. d) Contingency Solution Assumptions (thermal & voltage analysis): Area Interchange: Governor blocking: DC Converter Control: Generator Voltage Remote Control: Phase shifter control: Xfmr. Tap (TCUL s) Adjustment: Switched Shunt Devices (SVD s): Disabled. Baseload flag will be used per WECC practice. Enabled. Remote-regulating units will be reset to regulate their terminal bus at the predisturbance voltage. (Except Palo Verde #-# ). Disabled. Disabled. All manually-operated voltage control devices will be disabled/fixed.. Short Circuit Analysis Short circuit analysis was performed to determine the maximum fault currents on buses in the vicinity of the Project. This study assessed the impact of increased fault duty resulting from the Project for single line-toground and three-phase faults. Equipment that may become over-stressed as a result of the added generation was identified if the fault duty exceeds % of its applicable interrupting capability. The following scenarios are to be evaluated: ) Pre-Project, Heavy Summer system topology and all generation projects in the APS queue that are in the immediate region around Four Corners, and ) Post- Project, Heavy Summer system topology and all generation projects in the APS queue that are in the immediate region around Four Corners other. a) Circuit breakers exposed to fault currents in excess of percent of their interrupting capacities will be identified for replacement or upgrade, whichever is appropriate. b) The short circuit simulations to determine impacts (if any) on circuit breaker duties are generally performed within two buses away from the interconnection point of the Project. Fault Duty will be calculated at the following kv busses: Moenkopi, Four Corners, Cholla, Sugarloaf, and kv busses: Four Corners, Shiprock, San Juan, Cholla, West Mesa and Pinto. c) Short-circuit duty evaluations will be performed by the APS Protection Department using the APS s latest available database and the Computer Aided Protection Engineering ( CAPE ) application. Typically, short-circuit duty analysis simulates both single-phase and three-phase faults at specified busses. The resulting interrupting currents will be measured at each identified bus or breaker location, and compared for the Pre-Project and Post-Project scenarios. d) For the Pre-Project condition, the utilized protection database(s) will include future generation projects in neighboring Areas/busses to represent a most conservative scenario. e) All impedances will be expressed in per unit on a MVA base. The base voltage for each Per WECC power flow post-contingency methodology, all generators which control a high side remote bus will be set at the predisturbance voltage at the terminal bus, except for generators that have line-drop compensation. Consistent with prior studies of Palo Verde interconnections, Palo Verde units #- will continue to regulate the (remote) kv bus. Page

11 Four Corners kv Generator Interconnections Q- impedance element will be the nominal voltage for that part of the system in which the impedance occurs. Some base voltages are kv, kv, kv, kv, kv, kv, and kv. f) System elements represented in the model will be lines, transformers, generators and loads. Each element will be represented as complex impedance in the three-symmetrical component network (positive, negative, and zero sequences). g) The pre-fault voltage will be assumed to be. per unit of the base voltage for the bus being faulted. h) As appropriate for selected fault simulations in the vicinity of Navajo and/or Palo Verde, the short circuit calculation will include bypassing ( flashing ) of series capacitors. i) Shunt capacitor banks will be omitted at all stations. Normally, shunt capacitors produce a minimal effect on fault currents. When they are large enough to be significant, their effect is to reduce total fault current. Results are more conservative to neglect them altogether. j) Shunt reactors will also be neglected since their contribution is minimal. k) Reactors connected to auto-transformer delta tertiary windings will be neglected since they cannot contribute fault current to the system. l) Phase shifting transformers will be bypassed as this would be the worst case from the fault current standpoint. m) If zero sequence data is not available for transmission lines, the assumption will be made that Xo=X and Ro= or R. n) Line susceptances will be modeled for all circuits kv.. Network Capability Criteria The available transfer capability (ATC) of the APS owned transmission between the Four Corners kv switchyard and the Phoenix area will be evaluated for the summer time frame to determine if sufficient capacity exists to accommodate the MW of new generation. If insufficient capacity exists, a plan of facility additions will be developed to increase the ATC sufficiently to accommodate the entire MW. No power flow work will be performed to demonstrate the impact of planned facility additions. Such work will be pursued in the System Impact Study if the generation customer still wishes to pursue Network Resource interconnection service.. Power Factor Evaluation The APS OATT policy regarding power factor requires all Interconnection Customers, with the exception of wind generators, to maintain an acceptable power factor (typically near unity) at the Point of Interconnection (POI), subject to system conditions. The APS OATT also requires Interconnection Customers to be able to achieve +/-. power factor at the POI, with the maximum "full-output" VAr capability available at all outputs. Furthermore, APS requires Interconnection Customers to have dynamic voltage control and maintain the voltage as specified by the transmission operator within the limitation of +/-. power factor, as long as the Project is online and generating. If the Project s equipment is not capable of this type of response, a dynamic reactive device will be required. APS has the right to disconnect the Project if system conditions dictate the need to do so in order to maintain system reliability. To determine the total MVAR requirements, each project is to be modeled to inject its rated MW (less losses) at the POI as well as the corresponding amount of MVAR (.p.f.). The individual projects generators will have MVAR generation set Page

12 Four Corners kv Generator Interconnections Q- to the rated. p.f. and a shunt capacitor with an open MVAR limit will also be modeled to supply the necessary MVAR to cover losses. The resulting output of the unit (s) and shunt capacitors will be the total amount of MVAR capability required for the project. APS allows the project's reactive support to be made up of dynamic VAr and switched static VAr devices. The reactive devices used to achieve +/-. power factor as measured at the generator terminal must be dynamic. Any additional reactive support required to compensate for losses between the generator terminals and the POI may be made up of switched static reactive devices and/or any additional reactive capability of the generator beyond. power factor. The dynamic reactive power requirement is based upon the +/-. power factor requirement and is calculated as follows: MVAr Dynamic project. pf sin cos. pf Page

13 Four Corners kv Generator Interconnections Q- Study Results. Power Flow Power flow analysis was performed on all pre and post-project power flow cases. The results were compared to determine the impacts caused solely by the addition of the Project and to identify the system reinforcements necessary to mitigate the adverse impacts. These Pre-Project and Post-Project cases were evaluated for Category A (N- or all lines in service) conditions. Then approximately Category B and Category C contingencies were applied to the cases. Appendix provides a matrix of intended contingencies and their application to various Pre-and Post- Project power flow base cases. Select power flow plots are included in Appendix. Path The Heavy Summer pre-project case had a heavily stressed Path. Adding the Project ( MW) to the Four Corners kv bus, whether dispatched to Arizona or California, resulted in Path flows of MW (AZ) and MW (CA), well above nominal value of MW and inside the generation trip region. Given this stressed scenario, reducing the Project output to MW reduced the Path flows below nominal, but still on the edge of the nomogram. These results indicate the Project would have restrictions placed upon it as to when and how much it could generate and remain within the nomogram limitations. Table.: Path Flows Path Flows Base Case Heavy Summer Case Pre- Project Post- Project Post- Project Sensitivity FC, & off Pre- Project Post- Project HS Dispatch = MW "AZ" "CAISO" "AZ" "AZ" "CAISO" Path Path A kv Path B kv Nominal Rating = MW N- Overloads The results of the power flow analysis showed four N- Project-triggered overloads for the Heavy Summer case and no Project-triggered N- overloads for the sensitivity case with Four Corners Units,, & off. There were also pre-existing overloads. The results are shown below. Table.: N- Overloads Monitored Branch or Transformer % Emergency Rating Heavy Summer Sensitivity: FC,& off Post Post Post Area Rating Units Contingency Description Pre to to Pre to AZ CA AZ COLBRAN / kv MVA N- Unit# N- -PINTO kv CURECANT -SOCANAL kv Amps N- Unit# / kv # MVA N- / kv # CLAPHAM-GLADSTON kv Amps N- Unit # GLENCANY / kv # MVA N- -MOENKOPI kv GLENCANY / kv # MVA N- -MOENKOPI kv GLEN PS - GLENCANY kv MVA N- -MOENKOPI kv Page

14 Four Corners kv Generator Interconnections Q- The above N- overloads may be addressed with a RAS, arming the necessary Project generation to trip in the event of the applicable outage. Loss of a Four Corners / kv transformer - reduce dispatch to MW. This results in ~% loading on the remaining Four Corners / kv transformer. Loss of Four Corners-Moenkopi kv line - reduce dispatch to MW. This results in ~% loading on the Glen Canyon / kv transformers and < % loading on the Glen PS-Glen Canyon kv line. N- Overloads The results of the power flow analysis showed three N- Project-triggered overloads for the Heavy Summer case with a fourth line increased from % to ~%. The results from the sensitivity case, with Four Corners Units, & off, showed the Project triggered one N- overload. The results are shown below. Table.: N- Overloads Monitored Branch or Transformer % Emergency Rating Heavy Summer Sensitivity: FC,& off Post Post Post Area Rating Units Contingency Description Pre to to Pre to AZ CA CA - LEUPP kv Amps N- CH-SG & CO-SK kv w/ RAS < - MAZATZAL kv Amps N- CH-SG & CO-SK kv w/ RAS - PRECHCYN kv Amps N- CH-SG & CO-SK kv w/ RAS < COCONINO - LEUPP kv Amps N- CH-SG & CO-SK kv w/ RAS < E. LOOP - PANTANO kv Amps N- CH-SG & CO-SK kv w/ RAS < E. LOOP - TWNTYSEC kv Amps N- CH-SG & CO-SK kv w/ RAS GLENCANY / kv # MVA N- CH-SG & CO-SK kv w/ RAS < < < GLENCANY / kv # MVA N- CH-SG & CO-SK kv w/ RAS < < < - MAZATZAL kv Amps N- CH-SG & CO-SK kv w/ RAS < - PRECHCYN kv Amps N- CH-SG & CO-SK kv w/ RAS < < < VAIL - TECHPARK kv Amps N- CH-SG & CO-SK kv w/ RAS < VAIL kv - VAIL kv MVA N- CH-SG & CO-SK kv w/ RAS CINIZA - PEGS kv Amps N- SAN_MCK kv #& CINIZA - WINGATE kv Amps N- SAN_MCK kv #& Notes:. CH-SG & CO-SK = Cholla-Saguaro kv and Coronado-Silverking kv with tripping one Coronado unit..san_mck kv #& = San Juan-McKinley kv # & The above N- overloads may be addressed with a RAS, arming the necessary Project generation to trip in the event of the applicable outage. HS: N- Loss of Cholla-Saguaro and Coronado-Silverking kv lines with RAS of one Coronado unit - The entire Project would be armed for tripping, and queued as the first units to trip for this contingency. N- Loss of San Juan-McKinley #& kv lines - reduce dispatch to MW. This results in ~% loading on the Ciniza - Pegs kv line and < % loading on the Ciniza - Wingate kv line. Sensitivity: N- Loss of Cholla-Saguaro and Coronado-Silverking kv lines with RAS of one Coronado unitreduce dispatch to MW. This results in ~% loading on the Cholla-Mazatzal kv line and ~% loading on the Pinnacle Peak-Mazatzal kv line. Page

15 Four Corners kv Generator Interconnections Q- Voltage Deviation The results of the governor power flow analysis indicate the Project did not trigger any voltage deviation violations. Table. below shows pre-project voltage rise at Mazatzal kv and Mazatzal kv buses. Voltage correction on the lower voltage system would adjust for this. Table.: Voltage Deviation Monitored Branch or Transformer % Emergency Rating Heavy Summer Sensitivity: FC,& off Post Post Post Area Contingency Description Pre to to Pre to AZ CA CA MAZATZAL kv N- MAZATZAL-PINNACLE PEAK kv MAZATZAL kv N- MAZATZAL-PINNACLE PEAK kv Minimum Bus Voltage Violations: N- The Western Arizona Transmission System Task Force (WATS) voltage criterion in Appendix was used to screen for low voltages throughout the region. Table. shows the pre- and post-project violations under normal (N-) conditions. There were multiple buses in the LADWP and MWD systems that had violations but none were attributed to the addition of the Project. Table.: Minimum Bus Voltage Violations: N- % Emergency Rating Heavy Summer Sensitivity: FC,& off Violation Bus kv Pre Post to AZ Post to CA Pre Post to CA MWD KV VOLTAGE LESS THAN. PU GENE N..... MWD KV VOLTAGE LESS THAN. PU GENE S..... MWD KV VOLTAGE LESS THAN. PU INTK N..... MWD KV VOLTAGE LESS THAN. PU INTK S..... LADWP - KV VOLTAGE LESS THAN. PU TOLUCA. LADWP - KV VOLTAGE LESS THAN. PU HOLYWD_E.... LADWP - KV VOLTAGE LESS THAN. PU NRTHRDGE..... LADWP - KV VOLTAGE LESS THAN. PU TARZANA..... LADWP - KV VOLTAGE LESS THAN. PU SYLMAR.. LADWP - KV VOLTAGE LESS THAN. PU HOLYWD_F..... Short Circuit Short circuit analysis of the proposed generator interconnection was performed by the APS Protection Department, using the CAPE program and parameters supplied by the IC. Single line-to-ground (SLG) and three-phase faults were simulated with and without the Project to determine if there are any overstressed circuit breakers caused by the addition of the Project. Study results indicate the Project does not create any breaker overloads. Table. tabulates the Pre and Post Project fault duties at nearby busses. Page

16 Four Corners kv Generator Interconnections Q- Table.: Fault Duty Results *Currently not modeled in APS fault duty data base. The data base will be updated for the System Impact Study. Station Ph. (ka) X/R Pre-Project Ph-G (ka) X/R Post-Project Min. Breaker Rating (ka) Cholla kv Cholla kv Four Corners kv Four Corners kv Four Corners kv Moenkopi kv Pinto kv n/a Pillar kv * n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a San Juan kv n/a Shiprock kv Shiprock kv Sugarloaf kv West Mesa kv * n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a Ph. (ka) ΔI X/R Ph-G (ka) ΔI X/R. Network Capability Analysis At the time of this study, APS had no ATC from the Four Corners substations for Network Transmission service. This is based upon the assumption that Four Corners units,, and are in service. Even with those units off line, APS will secure additional Four Corners generation capacity which will be of a larger value than the decrease from the loss of units, and. The associated transmission plans for this generation change is for APS to reacquire the rights on the Four Corners-Moenkopi kv line. Network rights on this line for the increased net Four Corners generation have been reserved. At the time of this study, there is a substantial queue for the additional capacity on the Four Corners-Moenkopi line that exceed the capacity of that line. To be able to accommodate Q- projects as Network Resources, substantial new transmission would need to be built. A new line from the Four Corners area to the Phoenix area would be extremely expensive, somewhere in the ball park of $ billion.. Mitigation The Project will be armed for tripping as part of several RASs. Table.: RAS: Project generation tripping Generation Tripping Contingency Description Heavy Summer Sensitivity: FC,& off N- / kv # or # Reduce dispatch to MW n/a N- -MOENKOPI kv Reduce dispatch to MW n/a N- CH-SG & CO-SK kv w/ RAS Arm entire Project Reduce dispatch to MW N- SAN_MCK kv #& Reduce dispatch to MW n/a In addition, for the Heavy Summer case the Project would have restrictions placed upon it as to when and how much it could generate and remain within the Path nomogram limitations, as discussed in section.. Page

17 Four Corners kv Generator Interconnections Q-. Power Factor Evaluation The reactive devices used to achieve +/-. power factor as measured at the generator terminal must be dynamic. Any additional reactive support required to compensate for losses between the generator terminals and the POI may be made up of switched static reactive devices and/or any additional reactive capability of the generator beyond. power factor. A detailed plot of the evaluation results is contained in Appendix. Table.: MVAR Requirements Project Dynamic MVAR Requirements Estimated MVAR Losses* Estimated Total MVAR Requirements* Net POI Q ( MW) Q ( MW) Q ( MW) Q ( MW) Q ( MW) Q ( MW) * The estimated total MVAR requirements are based on the preliminary Project modeling data provided for the Feasibility Study. These values will be updated in the System Impact Study when a more detailed project model for the transmission lines and transformers is known. Cost and Construction Schedule Estimates The cost and time estimates represent good faith estimates necessary to interconnect to the system. The costs do not include any costs for new rights-of-way that may potentially be needed for some upgrades or for Transmission Line Siting activities that would need to be performed. The non-binding, good faith cost and time estimates are tabulated below. Table. Network Upgrades Estimated Cost Schedule Extend FC kv switchyard and move termination $, / of emission abatement # interconnection to a new bay, including a new breaker. Remedial Action Scheme $, / Total $, / Page

18 Four Corners kv Generator Interconnections Q- Table. Transmission Provider Interconnection Facilities Estimated Schedule Cost Termination facilities in FC kv switchyard (including breaker, A-frames, line disconnect switch, CCVTs, extended range CTs) for four terminations ($k each) $,, / / / / Protective relaying for four terminations ($k each) $, / Exits for four interconnections to edge of Four Corners Site property $,, / / / / Total $,, / / / / Included in the cost assumptions is an extension of the Four Corners kv main and transfer buses to accommodate two new terminations (bays & ). This is the maximum expansion possible for the kv switchyard. The termination of the emission abatement # interconnection will need to be moved from its existing location to the last of the new bays (#). At this time those costs of moving the existing interconnection are shown as Network Upgrades, but further evaluation is needed since these facilities may not be in the established FERC transmission system and hence may need to be classified differently. Three existing bay positions are open for the new terminations and one new bay position will be available with the bus extension. This totals four termination positions which is two short of the requested six new terminations. As such a new kv gathering switchyard is visualized to be just outside the Four Corners property and will be owned, built and operated by the generator interconnectors. No costs have been developed for any of the facilities off the Four Corners property although a one-line diagram has been included to represent the new gathering switchyard. If Four Corners units, and were removed, three additional bays could become available for the projects to directly terminate into the Four Corners kv switchyard. However, bringing in more than the displayed four new interconnection lines poses a real physical challenge. The costs to move things around on the Four Corners property could be quite expensive and could result in the gathering switchyard being the least expensive option. To that point, the gathering switchyard could be built to accommodate all six generation projects and bring in only one or two interconnection lines. An interconnection line could easily be built to have the capacity to carry the total MW of generation capacity. The fate of Four Corners units,, and will most likely not be known before these generation projects need to commit to LGIAs and construction plans. The new generation projects will need to be incorporated into the Four Corners unit tripping scheme to maintain the path ratings for the kv and kv system of APS. A nominal amount of cost is expected for this effort. All the costs for the four interconnection components are Transmission Provider Interconnection Facilities which are the sole cost responsibility of the Project and APS will have no repayment obligations. The attached diagram # shows a four breaker kv gathering switchyard that is expected to be developed and owned by the generator interconnection projects. The attached diagram # identifies additions and changes to the Four Corners kv switchyard. Siting kv lines from the individual projects to the Four Corners switchyard, a new switchyard and acquiring the ROW will likely take two years or more. Some of the land involved is tribal land and the process involving such has previously shown to take longer periods of time than originally estimated. An Environmental Impact Study would be required. The design, permitting, procurement, and construction time of this substation and interconnection work at the Four Corners site would be approximately months. Construction schedule estimates are from the date the Interconnection Customer provides written authorization to proceed, provided all interconnection agreements and funding arrangements are in place. These timing pieces indicate that a in service date for a project is considered to be unachievable. Page

19 Four Corners kv Generator Interconnections Q- Figure.: Page

20 Four Corners kv Generator Interconnections Q- Figure.: Page

21 Appendix Power Flow Plots

22 Plot # Case Case Description N- / Contingency Plot -pre HS: Pre-Project N- MW/MVAr -post HS: Post-Project to AZ N- MW/MVAr -post HS: Post-Project to CA N- MW/MVAr -pre Sensitivity: Pre-Project N- MW/MVAr -post Sensitivity: Post-Project N- MW/MVAr -post HS: Post-Project to AZ N- Four Corners- Moenkopi kv MVA/% -post HS: Post-Project to AZ N- Four Corners / kv # MVA/% -post HS: Post-Project to AZ N- Four Corners Unit MVA/% -post Sensitivity: Post-Project N- Four Corners- Moenkopi kv MVA/% -post Sensitivity: Post-Project N- Four Corners / kv # MVA/% -post HS: Post-Project to AZ -post HS: Post-Project to AZ -post Sensitivity: Post-Project -post -pre N- San Juan-McKinley kv #& N- Cholla-Saguaro & Coronado-Silverking kv w/ RAS N- Cholla-Saguaro & Coronado-Silverking kv w/ RAS MVA/% MVA/% MVA/% HS: Post-Project to AZ N-: Incremental Flows MW/MVAr -post HS: Post-Project to AZ Power Factor Evaluation MW/MVAr

23 H ALLEN. ADELANTO.. b. CRSTLPS CRSTLPS. COLRIVER.. N.GILA. CRSTL N MARKETPLACE. MCCULLGH. ELDORADO.. ARLINTON DELANY KV KV. PEACOCK HASSYAMP. CRYSTAL. PERKINS. LIBERTY.. MOENKOPI. RUDD. JOJOBA. Feasibility Study - Project Q - Q Q GILA RIVER PINAL_W.. RME.. YAVAPAI.. DUKE.. BROWNING. SOUTH. MORGAN. DUGAS PRECHCYN. SILVERKING. ABEL. MAZATZAL. PINAL_C.. FCW kv.. FCNGNCC. SAGUARO. TORTOLIT. FCNGNCC SGRLF... kv. PINTO PS.... FCNGEN FCNGEN FCNGEN WESTMESA... PILLAR. VAIL.. kv SPRINGR GREENLEE. SANJN PS. LUNA. SJUAN_G SJUAN_G SJUAN_G MCKINLEY... SJUAN_G SANJUAN TOTAL NET GENERATION KV VOLTAGES FLOW SUMMARY PINPKAPS.. EOR (Path ) WOR (Path ).. TOTAL WEST.. ARL GEN. WOR (NORTH). EAST. GILA RIVER Q HOOVER SAN JUAN SILVERKG SAG().... MIDWAY-VINCENT KRAMER-LUGO SOCAL IMPORT COI... PATH (CH-PNPK) PATH (NAV SO) NTP.... PATH. DESERT ROCK SPRINGERV LUGO. PDCI. PATH A (kv). DBG GEN Q TOT C NE/SE.. PATH B (kv) PATH ( Corn.).. General Electric International, Inc. PSLF Program Fri Jul :: _hs_pre-.sav HS Case, Q- Feasibility Study WECC. Case hsa, USE updated to reflect transmission Case : Pre-Project Q- MW to Four Corners kv MW/MVAR aps-ehv-hs-q--r Rating =

24 H ALLEN. ADELANTO.. b. CRSTLPS CRSTLPS. COLRIVER.. N.GILA. CRSTL N MARKETPLACE. MCCULLGH. ELDORADO.. ARLINTON DELANY KV KV.. PEACOCK HASSYAMP. CRYSTAL. PERKINS. LIBERTY.. MOENKOPI. RUDD. JOJOBA. Feasibility Study - Project Q - Q Q GILA RIVER PINAL_W.. RME.. YAVAPAI.. DUKE.. BROWNING. SOUTH. MORGAN. DUGAS PRECHCYN. SILVERKING. ABEL. MAZATZAL. PINAL_C.. FCW kv.. FCNGNCC. SAGUARO. TORTOLIT. FCNGNCC SGRLF... kv. PINTO PS.... FCNGEN FCNGEN FCNGEN WESTMESA... PILLAR. Q Q Q VAIL.. kv Q SPRINGR Q GREENLEE. Q SANJN PS. LUNA. SJUAN_G SJUAN_G SJUAN_G SJUAN_G MCKINLEY... SANJUAN. TOTAL NET GENERATION KV VOLTAGES FLOW SUMMARY PINPKAPS.. EOR (Path ) WOR (Path ).. TOTAL WEST.. ARL GEN. WOR (NORTH). EAST. GILA RIVER Q HOOVER SAN JUAN SILVERKG SAG().... MIDWAY-VINCENT KRAMER-LUGO SOCAL IMPORT COI... PATH (CH-PNPK) PATH (NAV SO) NTP.... PATH. DESERT ROCK SPRINGERV LUGO. PDCI. PATH A (kv). DBG GEN Q TOT C NE/SE -.. PATH B (kv) PATH ( Corn.).. General Electric International, Inc. PSLF Program Fri Jul :: c:\zaps_q-\pt-perl\_hs_pst-_toaz-mw-vaa-.sav HS Case, Q- Feasibility Study Case : Post-Project WECC. Case hsa, USE updated to reflect transmission Q- MW to Four Corners kv MW/MVAR aps-ehv-hs-q--ps Dispatch to AZ Rating =

25 H ALLEN. ADELANTO.. b. CRSTLPS CRSTLPS. COLRIVER.. N.GILA. CRSTL N MARKETPLACE. MCCULLGH. ELDORADO.. ARLINTON DELANY KV KV.. PEACOCK HASSYAMP. CRYSTAL. PERKINS. LIBERTY.. MOENKOPI. RUDD. JOJOBA. Feasibility Study - Project Q - Q Q GILA RIVER PINAL_W.. RME.. YAVAPAI.. DUKE.. BROWNING. SOUTH. MORGAN. DUGAS PRECHCYN. SILVERKING. ABEL. MAZATZAL. PINAL_C.. FCW kv.. FCNGNCC. SAGUARO. TORTOLIT. FCNGNCC SGRLF... kv. PINTO PS.... FCNGEN FCNGEN FCNGEN WESTMESA... PILLAR. Q Q Q VAIL.. kv Q SPRINGR Q GREENLEE. Q SANJN PS. LUNA. SJUAN_G SJUAN_G SJUAN_G SJUAN_G MCKINLEY... SANJUAN. TOTAL NET GENERATION KV VOLTAGES FLOW SUMMARY PINPKAPS.. EOR (Path ) WOR (Path ).. TOTAL WEST.. ARL GEN. WOR (NORTH). EAST. GILA RIVER Q HOOVER SAN JUAN SILVERKG SAG().... MIDWAY-VINCENT KRAMER-LUGO SOCAL IMPORT COI... PATH (CH-PNPK) PATH (NAV SO) NTP.... PATH. DESERT ROCK SPRINGERV LUGO. PDCI. PATH A (kv). DBG GEN Q TOT C NE/SE -.. PATH B (kv) PATH ( Corn.).. General Electric International, Inc. PSLF Program Fri Jul :: _hs_pst-_toca-mw-vaa.sav HS Case, Q- Feasibility Study WECC. Case hsa, USE updated to reflect transmission Case : Post-Project Q- MW to Four Corners kv Dispatch to CA MW/MVAR aps-ehv-hs-q--ps Rating =

26 H ALLEN. ADELANTO.. b. CRSTLPS CRSTLPS. COLRIVER.. N.GILA. CRSTL N MARKETPLACE. MCCULLGH. ELDORADO.. ARLINTON DELANY KV KV. PEACOCK HASSYAMP. CRYSTAL. PERKINS. LIBERTY.. MOENKOPI. RUDD. JOJOBA. Feasibility Study - Project Q - Q Q GILA RIVER PINAL_W.. RME.. YAVAPAI.. DUKE.. BROWNING. SOUTH. MORGAN. DUGAS PRECHCYN. SILVERKING. ABEL. MAZATZAL. PINAL_C.. FCW kv.. FCNGNCC. SAGUARO. TORTOLIT. FCNGNCC SGRLF... kv. PINTO PS.... FCNGEN FCNGEN FCNGEN WESTMESA... PILLAR. VAIL.. kv SPRINGR GREENLEE. SANJN PS. LUNA. SJUAN_G SJUAN_G SJUAN_G MCKINLEY... SJUAN_G SANJUAN TOTAL NET GENERATION KV VOLTAGES FLOW SUMMARY PINPKAPS.. EOR (Path ) WOR (Path ).. TOTAL WEST.. ARL GEN. WOR (NORTH). EAST. GILA RIVER Q HOOVER SAN JUAN SILVERKG SAG().... MIDWAY-VINCENT KRAMER-LUGO SOCAL IMPORT COI... PATH (CH-PNPK) PATH (NAV SO) NTP.... PATH. DESERT ROCK SPRINGERV LUGO. PDCI. PATH A (kv). DBG GEN Q TOT C NE/SE.. PATH B (kv) PATH ( Corn.).. General Electric International, Inc. PSLF Program Fri Jul :: c:\zaps_q-\pt-perl\_hs_pre-_no-fc.sav HS Case, Q- Feasibility Study WECC. Case hsa, USE updated to reflect transmission Case : Pre-Project Q- MW to Four Corners kv Case : Pre-Project_No FC gen,& MW/MVAR aps-ehv-hs-q--r Rating =

27 H ALLEN. ADELANTO.. b. CRSTLPS CRSTLPS. COLRIVER.. N.GILA. CRSTL N MARKETPLACE. MCCULLGH. ELDORADO.. ARLINTON DELANY KV KV.. PEACOCK HASSYAMP. CRYSTAL. PERKINS. LIBERTY.. MOENKOPI. RUDD. JOJOBA. Feasibility Study - Project Q - Q Q GILA RIVER PINAL_W.. RME.. YAVAPAI.. DUKE.. BROWNING. SOUTH. MORGAN. DUGAS PRECHCYN. SILVERKING. ABEL. MAZATZAL. PINAL_C.. FCW kv.. FCNGNCC. SAGUARO. TORTOLIT. FCNGNCC SGRLF... kv. PINTO PS.... FCNGEN FCNGEN FCNGEN WESTMESA... PILLAR. Q Q Q VAIL.. kv Q SPRINGR Q GREENLEE. Q SANJN PS. LUNA. SJUAN_G SJUAN_G SJUAN_G SJUAN_G MCKINLEY... SANJUAN. TOTAL NET GENERATION KV VOLTAGES FLOW SUMMARY PINPKAPS.. EOR (Path ) WOR (Path ).. TOTAL WEST.. ARL GEN. WOR (NORTH). EAST. GILA RIVER Q HOOVER SAN JUAN SILVERKG SAG().... MIDWAY-VINCENT KRAMER-LUGO SOCAL IMPORT COI... PATH (CH-PNPK) PATH (NAV SO) NTP.... PATH. DESERT ROCK SPRINGERV LUGO. PDCI. PATH A (kv). DBG GEN Q TOT C NE/SE.. PATH B (kv) PATH ( Corn.).. General Electric International, Inc. PSLF Program Fri Jul :: c:\zaps_q-\pt-perl\_hs_pst-_no-fc-vaa.sav HS Case, Q- Feasibility Study Case : Post-Project with FC Units,, off WECC. Case hsa, USE updated to reflect transmission Q- MW to Four Corners kv MW/MVAR aps-ehv-hs-q--ps Dispatch to AZ Rating =

28 H ALLEN. ADELANTO.. -. b CRSTLPS CRSTLPS. COLRIVER.. N.GILA. CRSTL N MARKETPLACE. MCCULLGH. ELDORADO.. ARLINTON DELANY KV KV. HASSYAMP. PEACOCK CRYSTAL. PERKINS. LIBERTY.. MOENKOPI. RUDD. JOJOBA. Feasibility Study - Project Q - Q Q GILA RIVER PINAL_W.. RME.. YAVAPAI.. DUKE.. BROWNING. SOUTH. MORGAN. DUGAS PRECHCYN. SILVERKING. ABEL. MAZATZAL. PINAL_C.. FCW kv.. FCNGNCC. SAGUARO. TORTOLIT. FCNGNCC SGRLF... kv. PINTO PS.... FCNGEN FCNGEN FCNGEN WESTMESA... PILLAR. Q Q Q VAIL.. kv Q SPRINGR Q GREENLEE. Q SANJN PS. LUNA. SJUAN_G SJUAN_G SJUAN_G SJUAN_G MCKINLEY... SANJUAN. TOTAL NET GENERATION KV VOLTAGES FLOW SUMMARY PINPKAPS.. EOR (Path ) WOR (Path ).. TOTAL WEST.. ARL GEN. WOR (NORTH). EAST. GILA RIVER Q HOOVER SAN JUAN SILVERKG SAG().... MIDWAY-VINCENT KRAMER-LUGO SOCAL IMPORT COI... PATH (CH-PNPK) PATH (NAV SO) NTP.... PATH. DESERT ROCK SPRINGERV LUGO. PDCI. PATH A (kv). DBG GEN Q TOT C NE/SE.. PATH B (kv) PATH ( Corn.). -. HS Case, Q- Feasibility Study Case : Post-Project WECC. Case hsa, USE updated to reflect transmission Q- MW to Four Corners kv MVA/%rate aps-ehv-hs-q--ps Dispatch to AZ Rating =

29 H ALLEN. ADELANTO.. -. b CRSTLPS CRSTLPS. COLRIVER.. N.GILA. CRSTL N MARKETPLACE. MCCULLGH. ELDORADO.. ARLINTON DELANY KV KV. HASSYAMP. PEACOCK CRYSTAL. PERKINS. LIBERTY.. MOENKOPI. RUDD. JOJOBA. Feasibility Study - Project Q - Q Q GILA RIVER PINAL_W.. RME.. YAVAPAI.. DUKE.. BROWNING. SOUTH. MORGAN. DUGAS PRECHCYN. SILVERKING. ABEL. MAZATZAL. PINAL_C.. FCW kv.. FCNGNCC. SAGUARO. TORTOLIT. FCNGNCC SGRLF... kv. PINTO PS.... FCNGEN FCNGEN FCNGEN WESTMESA... PILLAR. Q Q Q VAIL.. kv Q SPRINGR Q GREENLEE. Q SANJN PS. LUNA. SJUAN_G SJUAN_G SJUAN_G SJUAN_G MCKINLEY... SANJUAN. TOTAL NET GENERATION KV VOLTAGES FLOW SUMMARY PINPKAPS.. EOR (Path ) WOR (Path ).. TOTAL WEST.. ARL GEN. WOR (NORTH). EAST. GILA RIVER Q HOOVER SAN JUAN SILVERKG SAG().... MIDWAY-VINCENT KRAMER-LUGO SOCAL IMPORT COI... PATH (CH-PNPK) PATH (NAV SO) NTP.... PATH. DESERT ROCK SPRINGERV LUGO. PDCI. PATH A (kv). DBG GEN Q TOT C NE/SE -.. PATH B (kv) PATH ( Corn.).. General Electric International, Inc. PSLF Program Fri Jul :: pt-_hs_pst-_toaz-mw-vaa-_ax-fcn_--.sav HS Case, Q- Feasibility Study Case : Post-Project WECC. Case hsa, USE updated to reflect transmission Q- MW to Four Corners kv MVA/%rate aps-ehv-hs-q--ps Dispatch to AZ Rating =

30 H ALLEN. ADELANTO.. -. b CRSTLPS CRSTLPS. COLRIVER.. N.GILA. CRSTL N MARKETPLACE. MCCULLGH. ELDORADO.. ARLINTON DELANY KV KV. HASSYAMP. PEACOCK CRYSTAL. PERKINS. LIBERTY.. MOENKOPI. RUDD. JOJOBA. Feasibility Study - Project Q - Q Q GILA RIVER PINAL_W.. RME.. YAVAPAI.. DUKE.. BROWNING. SOUTH. MORGAN. DUGAS PRECHCYN. SILVERKING. ABEL. MAZATZAL. PINAL_C.. FCW kv.. FCNGNCC. SAGUARO. TORTOLIT. FCNGNCC SGRLF... kv. PINTO PS.... FCNGEN FCNGEN FCNGEN WESTMESA... PILLAR. Q Q Q VAIL.. kv Q SPRINGR Q GREENLEE. Q SANJN PS. LUNA. SJUAN_G SJUAN_G SJUAN_G SJUAN_G MCKINLEY... SANJUAN. TOTAL NET GENERATION KV VOLTAGES FLOW SUMMARY PINPKAPS.. EOR (Path ) WOR (Path ).. TOTAL WEST.. ARL GEN. WOR (NORTH). EAST. GILA RIVER Q HOOVER SAN JUAN SILVERKG SAG().... MIDWAY-VINCENT KRAMER-LUGO SOCAL IMPORT COI... PATH (CH-PNPK) PATH (NAV SO) NTP.... PATH. DESERT ROCK SPRINGERV LUGO. PDCI. PATH A (kv). DBG GEN Q TOT C NE/SE.. PATH B (kv) PATH ( Corn.).. General Electric International, Inc. PSLF Program Fri Jul :: pt-_hs_pst-_toaz-mw-vaa- fcn-u-.sav HS Case, Q- Feasibility Study WECC. Case hsa, USE updated to reflect transmission Case : Post-Project Q- MW to Four Corners kv Dispatch to AZ MVA/%rate aps-ehv-hs-q--ps Rating =

31 H ALLEN. ADELANTO.. -. b CRSTLPS CRSTLPS. COLRIVER.. N.GILA. CRSTL N MARKETPLACE. MCCULLGH. ELDORADO.. ARLINTON DELANY KV KV. HASSYAMP. PEACOCK CRYSTAL. PERKINS. LIBERTY.. MOENKOPI. RUDD. JOJOBA. Feasibility Study - Project Q - Q Q GILA RIVER PINAL_W.. RME.. YAVAPAI.. DUKE.. BROWNING. SOUTH. MORGAN. DUGAS PRECHCYN. SILVERKING. ABEL. MAZATZAL. PINAL_C.. FCW kv.. FCNGNCC. SAGUARO. TORTOLIT. FCNGNCC SGRLF... kv. PINTO PS.... FCNGEN FCNGEN FCNGEN WESTMESA... PILLAR. Q Q Q VAIL.. kv Q SPRINGR Q GREENLEE. Q SANJN PS. LUNA. SJUAN_G SJUAN_G SJUAN_G SJUAN_G MCKINLEY... SANJUAN. TOTAL NET GENERATION KV VOLTAGES FLOW SUMMARY PINPKAPS.. EOR (Path ) WOR (Path ).. TOTAL WEST.. ARL GEN. WOR (NORTH). EAST. GILA RIVER Q HOOVER SAN JUAN SILVERKG SAG().... MIDWAY-VINCENT KRAMER-LUGO SOCAL IMPORT COI... PATH (CH-PNPK) PATH (NAV SO) NTP.... PATH. DESERT ROCK SPRINGERV LUGO. PDCI. PATH A (kv). DBG GEN Q TOT C NE/SE.. PATH B (kv) PATH ( Corn.). -. General Electric International, Inc. PSLF Program Fri Jul :: pt-_hs_pst-_no-fc-vaa_ax_fcn-mnk_-.sav HS Case, Q- Feasibility Study WECC. Case hsa, USE updated to reflect transmission Case : Post-Project with FC Units,, off Q- MW to Four Corners kv Dispatch to AZ MVA/%rate aps-ehv-hs-q--ps Rating =