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HomeMy WebLinkAbout20190821Avista to Staff 135 Attachment C.pdfLGIP #43 System Impact Study Report System Impact Study Report Project #43 October 30, 2015 Richard Maguire Avista System Planning Engineer Kevin Damron Avista System Protection Engineer Avista Project Account 77705266-186200 Staff_PR_135 Attachment C Page 1 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 2 of 52 Executive Summary On June 19, 2015, Avista received a completed Interconnection System Impact Study Request from the Project #43 Developer for a proposed 150 MW wind generating facility located near Lind, Washington. On July 28, 2015, Avista and the Project #43 Developer completed the Interconnection System Impact Study Agreement. The Interconnection Customer has given a projected initial operating date of December 31, 2016. The Interconnection System Impact Study Agreement states that Avista will study the possible interconnection of Project #43 at Lind Station. The goal of this study was to determine interconnection impacts, project requirements, and cost estimates necessary to integrate Project #43 as a Network Resource and also as an Energy Resource.1 Power flow, transient stability, and short circuit studies were used to measure the performance of the existing system and determine the adequacy of new facilities necessary to maintain proper system performance and reliability with Project #43 operating at full output. The study work indicates that this interconnection performs adequately and has no adverse impacts on the Transmission System when the identified network upgrades are completed. The estimated cost to fully interconnect Project #43 is approximately $22,017,000. This includes the rebuilding Lind Station and the increase in capacity of local transmission lines. The scheduled interconnection of Project #43 is dependent on the completion of a Facilities Study, Engineering and Procurement Agreement, and Interconnection Agreement. POI Project Output Schedule Total Cost ($000) Lind Station 150 MW Time to Construct = December 31, 2018 $22,017,000 All construction costs are in 2016-year dollars and are based on engineering judgment with +/- 20% error. These cost estimates assume that the Project #43 owners are responsible for all necessary facilities from their facility to the POI. NOTE: Project #43 output could still need to be curtailed in the event of planned or extended forced outages to some transmission system elements including, but not necessarily limited to, any transmission line segment between the Lind and Warden 115kV Switching Stations. 1 For this study, Energy Resource performance adequacy is assumed if Network Resource performance is proven Staff_PR_135 Attachment C Page 2 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 3 of 52 TABLE OF CONTENTS EXECUTIVE SUMMARY ................................................................................................................................... 2 INTRODUCTION ................................................................................................................................................ 4 GENERAL ........................................................................................................................................................... 4 Point of Interconnection (POI) ...................................................................................................................... 5 Scope of the System Impact Study .................................................................................................................. 7 Study Case Description and Development ...................................................................................................... 8 PRELIMINARY POWER FLOW STUDY .................................................................................................................. 13 Current System Capacity ............................................................................................................................. 13 Incremental Generation Analysis ................................................................................................................. 14 Thermal Performance .................................................................................................................................. 18 MITIGATING PROJECT ................................................................................................................................. 20 PROJECT REQUIREMENTS .................................................................................................................................. 21 Point of Interconnection (Lind Station): $7,550,000 ..................................................................................... 21 Transmission Line Requirements: $14,467,000 ............................................................................................ 22 STUDY RESULTS ............................................................................................................................................. 23 INCREMENTAL GENERATION ANALYSIS ............................................................................................................. 23 THERMAL PERFORMANCE ................................................................................................................................. 26 Base Case Impact ........................................................................................................................................ 26 Project #43 at Full Requested Output .......................................................................................................... 28 VOLTAGE PERFORMANCE ................................................................................................................................. 29 Base Case Voltage Performance .................................................................................................................. 29 Voltage Performance with Project #43 ........................................................................................................ 33 Contingency Voltage Performance ............................................................................................................... 36 Impacted Transmission Facilities ................................................................................................................ 38 SHORT CIRCUIT ANALYSIS ................................................................................................................................ 41 General:...................................................................................................................................................... 41 ASPEN Model Development: ....................................................................................................................... 42 Station Transformers ................................................................................................................................... 42 Collector String and Pad Mount GSUs ........................................................................................................ 42 Wind Turbines ............................................................................................................................................. 43 Fault Analysis Study .................................................................................................................................... 43 Fault Duty Comparisons.............................................................................................................................. 43 Summary ..................................................................................................................................................... 45 TRANSIENT STABILITY ...................................................................................................................................... 46 Method and Criteria .................................................................................................................................... 46 Transient Stability Results ........................................................................................................................... 47 CONCLUSION ..................................................................................................................................................... 2 APPENDIX A ....................................................................................................................................................... 3 ASPEN MODEL DEVELOPMENT: ......................................................................................................................... 3 Staff_PR_135 Attachment C Page 3 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 4 of 52 Introduction General In the application for Large Electric Generator Interconnection, the Project #43 Developer requested the study for Project #43 be conducted both for network resource interconnection service and energy resource interconnection service. Avista’s System Planning Group contends that if a generator is studied and can connect for Network Resource Interconnection Service then it can also connect for Energy Resource Interconnection Service. Energy Resource Interconnection Service allows the Interconnection Customer to connect the Large Generating Facility to the Transmission System and be eligible to deliver the Large Generating Facility's output using the existing firm or non-firm capacity of the Transmission System on an "as available" basis. Energy Resource Interconnection Service does not in and of itself convey any right to deliver electricity to any specific customer or Point of Delivery. For Network Resource Interconnection Service the Transmission Provider must conduct the necessary studies and construct the Network Upgrades needed to integrate the Large Generating Facility in a manner comparable to that in which the Transmission Provider integrates its generating facilities to serve native load customers. Network Resource Interconnection Service allows the Interconnection Customer’s Large Generating Facility to be designated as a Network Resource, up to the Large Generating Facility's full output, on the same basis as existing Network Resources interconnected to the Transmission Provider's Transmission System, and to be studied as a Network Resource on the assumption that such a designation will occur. Network Resource Interconnection Service in and of itself does not convey transmission service. Staff_PR_135 Attachment C Page 4 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 5 of 52 Point of Interconnection (POI) The System Impact Study Agreement states that Avista will study the interconnection of Project #43 in the vicinity of Avista’s Lind Station. Figure 1 presents a view of the local 115 kV Transmission System for the area surrounding the POI, and Figure 2 shows a one-line diagram of the project in a 2016 Heavy Summer base case scenario. Figure 1: Project #43 map Project #43 Staff_PR_135 Attachment C Page 5 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 6 of 52 Figure 2: Project #43 installed in 2016 Heavy Summer Base Case Staff_PR_135 Attachment C Page 6 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 7 of 52 Scope of the System Impact Study As outlined in Section 7.3 of Avista’s Large Generator Interconnection Procedures (LGIP), this study evaluates the impact of the proposed interconnection on the reliability of the Transmission System, and it consists of a power flow analysis, stability analysis, and a short circuit analysis. Of note for the scope of this study:  This study considers all other higher queued interconnection requests that directly impact the Project #43 interconnection.  The transmission additions simulated in the study cases were based on the best information available at the time the study was initiated. It is likely that the actual plan of service will differ from the plan of service studied, and Avista reserves the right to restudy this request if necessary.  Transmission capacity impacts and upgrades beyond the Transmission Provider’s Interconnection Facilities identified by this Interconnection System Impact Study Report are provided for informational purposes only. A complete analysis of these transmission capacity impacts associated with Project #43 and any facilities needed to mitigate the impacts would be identified through the study process for Transmission Service, once a request for Transmission Service has been made. The resulting Interconnection System Impact Study report includes the following information2:  Identification of facility thermal overloads or facility voltage violations resulting from the interconnection  Identification of transient stability violations resulting from the interconnection  Identification of any circuit breaker or equipment short circuit capability limits exceeded as a result of the interconnection.  Description and non-binding, good faith estimated cost of facilities required to interconnect the project to the Avista Transmission System.  Non-binding, good-faith estimate of time to construct. Avista System Planning coordinated the Interconnection System Impact study work with Affected Systems determined during the Interconnection Feasibility Study. 2 Thermal, voltage, and stability performance determined by reference to NERC Standard TPL-001-4 Staff_PR_135 Attachment C Page 7 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 8 of 52 Study Case Description and Development Power flow and stability analysis were performed using Heavy Summer and Heavy Winter Planning cases for 2016 and 2020 conditions. Avista Planning Cases are tailored from approved WECC cases, and a standardized set of steady state and stability contingency scenarios are run against each case for different levels of Project #43 generation. These contingencies include outages within the Avista Transmission System as well as select outages in adjacent Planning Coordinator and Transmission Planner areas. Contingencies are added or modified to include elements added to the Transmission System for the purposes of this study, and contingency events covering TPL-001-4 categories P0-P3 and P5-P7 are included. Staff_PR_135 Attachment C Page 8 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 9 of 52 2016 Heavy Summer This is the typical summer peak study where the balancing area load is heavy and the transmission system is at its most limiting condition due to high temperatures. A summary of regional flows is shown below. Western Montana Hydro 1225.2 MW West of Hatwai (Path 6) 406.6 MW Noxon Rapids (586MW) 420.0 MW Lolo-Oxbow 230kV 244.2 MW Cabinet Gorge (271MW) 240.0 MW Dry Creek-Walla Walla 230kV 127.5 MW Libby (605MW)375.2 MW Hungry Horse (430MW) 190.0 MW West of Cabinet 1474.8 MW Montana-Northwest (Path 8) 600.9 MW Colstrip Total Colstrip 1 (330MW)330.0 MW Idaho-Northwest (Path 14) -439.6 MW Colstrip 2 (330MW)330.0 MW Midpoint-Summer Lake (Path 75) -68.6 MW Colstrip 3 (823MW)787.2 MW Idaho-Montana (Path 18) -254.0 MW Colstrip 4 (823MW)820.0 MW South of Boundary 632.2 MW Rathdrum Thermal (175MW) 0.0 MW North of John Day (Path 73) 4647.4 MW Lancaster Thermal (270MW) 249.0 MW TOT 4A (Path 37)166.9 MW Spokane River Hydro 150.3 MW Miles City DC 158.0 MW Boundary Hydro (1040MW) 635.0 MW Path C (Path 20)-625.3 MW Lower Snake/N.F. Clearwater Borah West (Path 17)642.4 MW Dworshak (458MW)91.7 MW Bridger West (Path 19) 1954.4 MW Lower Granite (930MW) 554.0 MW Pacific AC Intertie (Path 66) 3957.8 MW Little Goose (930MW)555.0 MW Pacific DC Intertie (Path 65) 2000.0 MW Lower Monumental (930MW) 530.5 MW Northwest Load 24382.5 MW Coulee Generation Idaho Load 3700.0 MW Coulee 500 kV 2285.1 MW Montana Load 1939.3 MW Coulee 230 kV 1840.9 MW Avista Native Load -1682.4 MW Avista Balancing Area Load 2206.6 MW Clearwater Load 50.0 MW Staff_PR_135 Attachment C Page 9 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 10 of 52 2016 Heavy Winter This is the typical winter peak study where the balancing area load is at its peak. A summary of regional flows is shown below. Western Montana Hydro 680.0 MW West of Hatwai (Path 6) 140.1 MW Noxon Rapids (586MW) 292.0 MW Lolo-Oxbow 230kV 121.8 MW Cabinet Gorge (271MW) 185.0 MW Dry Creek-Walla Walla 230kV 84.5 MW Libby (605MW)108.0 MW Hungry Horse (430MW) 95.0 MW West of Cabinet 1170.7 MW Montana-Northwest (Path 8) 1031.3 MW Colstrip Total Colstrip 1 (330MW)330.0 MW Idaho-Northwest (Path 14) 130.6 MW Colstrip 2 (330MW)330.0 MW Midpoint-Summer Lake (Path 75) 236.3 MW Colstrip 3 (823MW)792.3 MW Idaho-Montana (Path 18) -99.9 MW Colstrip 4 (823MW)805.0 MW South of Boundary 509.5 MW Rathdrum Thermal (175MW) 0.0 MW North of John Day (Path 73) 2782.3 MW Lancaster Thermal (270MW) 273.0 MW TOT 4A (Path 37)119.0 MW Spokane River Hydro 149.0 MW Miles City DC 154.0 MW Boundary Hydro (1040MW) 510.0 MW Path C (Path 20)-326.2 MW Lower Snake/N.F. Clearwater Borah West (Path 17)818.3 MW Dworshak (458MW)408.0 MW Bridger West (Path 19) 1924.3 MW Lower Granite (930MW) 831.5 MW Pacific AC Intertie (Path 66) 1981.9 MW Little Goose (930MW)832.5 MW Pacific DC Intertie (Path 65) 1763.0 MW Lower Monumental (930MW) 783.0 MW Northwest Load 30208.3 MW Coulee Generation Idaho Load 2704.0 MW Coulee 500 kV 3788.9 MW Montana Load 1940.0 MW Coulee 230 kV 1621.3 MW Avista Native Load -1815.4 MW Avista Balancing Area Load 2415.4 MW Clearwater Load 55.0 MW Staff_PR_135 Attachment C Page 10 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 11 of 52 2020 Heavy Summer This is the typical summer peak study where the balancing area load is heavy and the transmission system is at its most limiting condition due to high temperatures. A summary of regional flows is shown below. Western Montana Hydro 1225.2 MW West of Hatwai (Path 6) 582.1 MW Noxon Rapids (586MW) 420.0 MW Lolo-Oxbow 230kV 230.5 MW Cabinet Gorge (271MW) 240.0 MW Dry Creek-Walla Walla 230kV 148.6 MW Libby (605MW)375.2 MW Hungry Horse (430MW) 190.0 MW West of Cabinet 1461.9 MW Montana-Northwest (Path 8) 635.9 MW Colstrip Total Colstrip 1 (330MW)330.0 MW Idaho-Northwest (Path 14) 36.9 MW Colstrip 2 (330MW)330.0 MW Midpoint-Summer Lake (Path 75) 338.0 MW Colstrip 3 (823MW)811.9 MW Idaho-Montana (Path 18) 306.0 MW Colstrip 4 (823MW)820.0 MW South of Boundary 632.8 MW Rathdrum Thermal (175MW) 0.0 MW North of John Day (Path 73) 5129.8 MW Lancaster Thermal (270MW) 249.0 MW TOT 4A (Path 37)189.7 MW Spokane River Hydro 150.3 MW Miles City DC 159.0 MW Boundary Hydro (1040MW) 635.0 MW Path C (Path 20)-736.3 MW Lower Snake/N.F. Clearwater Borah West (Path 17)683.9 MW Dworshak (458MW)316.0 MW Bridger West (Path 19) 1972.8 MW Lower Granite (930MW) 554.0 MW Pacific AC Intertie (Path 66) 4177.6 MW Little Goose (930MW)555.0 MW Pacific DC Intertie (Path 65) 2711.0 MW Lower Monumental (930MW) 533.0 MW Northwest Load 25950.5 MW Coulee Generation Idaho Load 4025.9 MW Coulee 500 kV 3898.3 MW Montana Load 2060.0 MW Coulee 230 kV 1944.5 MW Avista Native Load -1728.4 MW Avista Balancing Area Load 2252.9 MW Clearwater Load 50.0 MW Staff_PR_135 Attachment C Page 11 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 12 of 52 2020 Heavy Winter This is the typical winter peak study where the balancing area load is at its peak. A summary of regional flows is shown below. Western Montana Hydro 680.0 MW West of Hatwai (Path 6) 5.8 MW Noxon Rapids (586MW) 292.0 MW Lolo-Oxbow 230kV 108.6 MW Cabinet Gorge (271MW) 185.0 MW Dry Creek-Walla Walla 230kV 85.8 MW Libby (605MW)108.0 MW Hungry Horse (430MW) 95.0 MW West of Cabinet 1098.0 MW Montana-Northwest (Path 8) 987.3 MW Colstrip Total Colstrip 1 (330MW)330.0 MW Idaho-Northwest (Path 14) 78.8 MW Colstrip 2 (330MW)330.0 MW Midpoint-Summer Lake (Path 75) 145.3 MW Colstrip 3 (823MW)785.0 MW Idaho-Montana (Path 18) -68.7 MW Colstrip 4 (823MW)805.0 MW South of Boundary 508.6 MW Rathdrum Thermal (175MW) 0.0 MW North of John Day (Path 73) 2530.1 MW Lancaster Thermal (270MW) 273.0 MW TOT 4A (Path 37)191.1 MW Spokane River Hydro 149.0 MW Miles City DC 154.0 MW Boundary Hydro (1040MW) 510.0 MW Path C (Path 20)-464.2 MW Lower Snake/N.F. Clearwater Borah West (Path 17)813.2 MW Dworshak (458MW)408.0 MW Bridger West (Path 19) 1975.1 MW Lower Granite (930MW) 692.5 MW Pacific AC Intertie (Path 66) 942.3 MW Little Goose (930MW)832.5 MW Pacific DC Intertie (Path 65) 1473.0 MW Lower Monumental (930MW) 803.5 MW Northwest Load 32347.9 MW Coulee Generation Idaho Load 2860.9 MW Coulee 500 kV 4625.7 MW Montana Load 2030.1 MW Coulee 230 kV 1894.6 MW Avista Native Load -1865.2 MW Avista Balancing Area Load 2483.7 MW Clearwater Load 55.0 MW Staff_PR_135 Attachment C Page 12 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 13 of 52 Preliminary Power Flow Study Current System Capacity Interconnecting Project #43 to the existing Transmission System with all lines in service and increasing its output until the first facility reaches 90% thermal loading (OthelloSS to Warden) is shown in Figure 3. At this level of generation, the OthelloSS – Warden 115 kV Transmission Line overloads for 139 unique contingency scenarios in the 2020 Heavy Summer case. Figure 4 shows system response for the worst-case single-element outage: a line-end-open of the Othello SS – Warden 115 kV line. Interconnecting Project #43 at this level of generation would likely require station work at Lind and the installation of protection-level communications and a thermal tripping scheme to mitigate overloads. Note: This current system capacity analysis is for informational purposes only. Figure 3: 2020 Heavy Summer scenario with Project #43 generating 60 MW Figure 4: Worst-case, single-element outage for current system topology in 20HS case Staff_PR_135 Attachment C Page 13 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 14 of 52 Incremental Generation Analysis The software program Simulator from PowerWorld Corporation includes a tool – Available Transfer Capability (ATC) – that returns “next most limiting” facility thermal violations for incrementing levels of Project #43 generation. The ATC tool provides a helpful first-look at how the System reacts to increasing generation output from Project #43. Table 1 presents ATC results when using Avista generation to balance the project, giving an indication of how the System could perform if Project #43 is studied as a Network Resource Interconnection Service. Table 2 and Table 3 provide ATC results when studying Project #43 as an Energy Resource Interconnection Service, with the balancing coming from West of the project via Coulee generation or South of the project via Diablo Canyon generation. Coulee and Diablo Canyon were chosen solely for their location without any implication of actual service. Note that the different location of the Point of Receipt (POR) makes almost no difference in power flows local to the project, implying little difference in outcome if the project is studied as a Network or Energy Interconnection Service. Staff_PR_135 Attachment C Page 14 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 15 of 52 Table 1: ATC with AVA Generation balancing Project #43; 2016 Heavy Summer Base Case Proj #43 Limiting Element Limiting CTG % OTDF 15.81 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) -22.53 16.43 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Sand Dunes - Wheeler 230 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R)-22.71 17.42 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Stratford 115 kV (STR-WIL) + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) -22.53 19.08 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Columbia - Rocky Ford 115 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R)-22.58 21.19 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Midway - Mattawa - Wanapum 230 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) -22.47 34.23 Line BENTNAVA (48039) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] T-1: Benton 230/115 kV + T-1: White Bluff #1 230/115 kV -22.82 34.23 Line BENTNAVA (48039) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + T-1: White Bluff #1 230/115 kV -22.82 60.45 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Washtucna 115 kV 100 60.65 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Shawnee 115 kV (LIN-EWN)100 62.96 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] G-1: Summer Falls Units 1&2 + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 63.07 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] G-1: Marengo Wind Units 1&2 + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 63.18 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 118.47 Line BENTNAVA (48039) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #2 115 kV (OSS-L&R) + T-1: Benton 230/115 kV -22.1 118.47 Line BENTNAVA (48039) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #2 115 kV (OSS-L&R)-22.1 129.67 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] BF: A254 Warden 115 kV, Larson-Sand Dunes-Warden 67.39 158.63 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Othello SS 115 kV (OSS-SOT) + N-1: Sand Dunes - Warden #2 115 kV 100 161.11 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] BF: A308 Warden 115 kV, Othello SS-Warden #2 -74.74 161.22 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] BF: A308 Warden 115 kV, Othello SS-Warden #2 74.74 168.68 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #1 115 kV 20.29 168.68 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: Benton 230/115 kV 20.29 171.68 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Othello SS - Warden #2 115 kV (OSS-L&R)42.93 171.72 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] BF: A562 Othello SS 115 kV, Othello Switching Station-Warden #2 42.93 177.98 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Othello SS - Warden #1 115 kV 29.92 194.3 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: White Bluff #1 230/115 kV 20.55 212.78 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Sand Dunes - Warden #2 115 kV 32.94 Staff_PR_135 Attachment C Page 15 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 16 of 52 Table 2: ATC with Grand Coulee Generation balancing Project #43; 2016 Heavy Summer Base Case Proj #43 Limiting Element Limiting CTG % OTDF 16.28 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) -22.13 16.88 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Sand Dunes - Wheeler 230 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R)-22.31 17.83 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Stratford 115 kV (STR-WIL) + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) -22.13 19.47 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Columbia - Rocky Ford 115 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R)-22.17 21.63 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Midway - Mattawa - Wanapum 230 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) -22.08 35.25 Line BENTNAVA (48039) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] T-1: Benton 230/115 kV + T-1: White Bluff #1 230/115 kV -22.21 35.31 Line BENTNAVA (48039) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + T-1: White Bluff #1 230/115 kV -22.21 60.44 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Washtucna 115 kV 100 60.65 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Shawnee 115 kV (LIN-EWN)100 62.95 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] G-1: Summer Falls Units 1&2 + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 63.06 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] G-1: Marengo Wind Units 1&2 + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 63.18 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 121.01 Line BENTNAVA (48039) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #2 115 kV (OSS-L&R) + T-1: Benton 230/115 kV -21.62 121.01 Line BENTNAVA (48039) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #2 115 kV (OSS-L&R)-21.62 129.86 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] BF: A254 Warden 115 kV, Larson-Sand Dunes-Warden 67.39 158.61 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Othello SS 115 kV (OSS-SOT) + N-1: Sand Dunes - Warden #2 115 kV 100 161.31 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] BF: A308 Warden 115 kV, Othello SS-Warden #2 -74.74 161.41 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] BF: A308 Warden 115 kV, Othello SS-Warden #2 74.74 171.62 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Othello SS - Warden #2 115 kV (OSS-L&R)42.95 171.66 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] BF: A562 Othello SS 115 kV, Othello Switching Station-Warden #2 42.95 172.31 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #1 115 kV 19.85 172.31 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: Benton 230/115 kV 19.85 179.78 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Othello SS - Warden #1 115 kV 29.61 198.15 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: White Bluff #1 230/115 kV 20.14 214.77 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Sand Dunes - Warden #2 115 kV 32.63 233.61 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Othello SS - Warden #1 115 kV -29.61 Staff_PR_135 Attachment C Page 16 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 17 of 52 Table 3: ATC with Diablo Canyon Generation balancing Project #43; 2016 Heavy Summer Base Case Proj #43 Limiting Element Limiting CTG % OTDF 9.45 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Shawnee 115 kV (LIN-EWN)100 11.97 Line BENTNAVA (48039) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] T-1: Benton 230/115 kV + T-1: White Bluff #1 230/115 kV -23.21 12.44 Line BENTNAVA (48039) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + T-1: White Bluff #1 230/115 kV -23.21 18.26 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Washtucna 115 kV 100 21.51 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 21.76 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] G-1: Marengo Wind Units 1&2 + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 21.78 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] G-1: Summer Falls Units 1&2 + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 56.82 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Othello SS - Warden #2 115 kV (WAR-L&R)-22.8 59.4 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Columbia - Rocky Ford 115 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R)-22.84 59.45 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Stratford 115 kV (STR-WIL) + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) -22.8 59.61 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Sand Dunes - Wheeler 230 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R)-22.97 64.89 Line OTHELOSS (48309) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Midway - Mattawa - Wanapum 230 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) -22.74 116.9 Line BENTNAVA (48039) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #2 115 kV (OSS-L&R) + T-1: Benton 230/115 kV -22.4 116.9 Line BENTNAVA (48039) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #2 115 kV (OSS-L&R)-22.4 129.56 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] BF: A254 Warden 115 kV, Larson-Sand Dunes-Warden 67.39 158.63 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Othello SS 115 kV (OSS-SOT) + N-1: Sand Dunes - Warden #2 115 kV 100 160.99 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] BF: A308 Warden 115 kV, Othello SS-Warden #2 -74.74 161.1 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] BF: A308 Warden 115 kV, Othello SS-Warden #2 74.74 166.44 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: Benton 230/115 kV 20.57 166.44 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #1 115 kV 20.57 171.74 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Othello SS - Warden #2 115 kV (OSS-L&R)42.92 171.78 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] BF: A562 Othello SS 115 kV, Othello Switching Station-Warden #2 42.92 176.84 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Othello SS - Warden #1 115 kV 30.12 191.87 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: White Bluff #1 230/115 kV 20.81 211.48 Line OTHELLO (48307) TO OTHELOSS (48309) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Sand Dunes - Warden #2 115 kV 33.15 229.77 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Othello SS - Warden #1 115 kV -30.12 Staff_PR_135 Attachment C Page 17 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 18 of 52 Thermal Performance This study found interconnecting Project #43 to the existing Transmission System introduced 6,946 thermal facility violations on the following 115 kV transmission lines or line segments:  Lind – Roxboro 115 kV  Roxboro – Warden 115 kV  Othello Switching Station – Warden 115 kV  Benton AVA(ownership change) – South Othello Tap 115 kV  Othello Switching Station – Othello 115 kV Given the large number of violations recorded, the complete data set will not be presented in this study. In lieu of the complete data set, Table 4 presents a sample of the worst performing facility thermal violations found in this study, and Table 5 presents the sum of all Percent Overloads recorded for each facility overloaded during contingencies. Table 4: Worst performing violations for facilities overloaded by Project #43 Row Labels Ref Ctg Value Limit % Ref Ctg Value Limit % Ref Ctg Value Limit % Ref Ctg Value Limit % N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Othello SS - Warden #2 115 kV (OSS-L&R) LIND (48187) -> ROXBORO (48375) CKT 1 at LIND 661.73 669.51 286.16 233.96 ROXBORO (48375) -> WARDEN A (48455) CKT 1 at ROXBORO 579.78 593.63 286.16 207.44 568.48 578.55 286.16 202.17 WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 227.82 355.88 266.08 133.75 260.56 403.55 266.08 151.66 N-1: Benton - Midway 230 kV + T-1: White Bluff #1 230/115 kV WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 227.82 353.70 266.08 132.93 406.39 740.09 532.17 278.14 N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Washtucna 115 kV LIND (48187) -> ROXBORO (48375) CKT 1 at LIND 661.73 726.41 286.16 253.84 690.53 736.27 400.13 184.01 653.89 719.66 286.16 251.49 696.94 743.22 400.13 185.75 ROXBORO (48375) -> WARDEN A (48455) CKT 1 at ROXBORO 579.78 643.34 286.16 224.81 680.14 725.88 400.13 181.41 568.48 633.35 286.16 221.32 686.68 732.94 400.13 183.18 WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 260.56 270.32 266.08 101.59 N-1: Othello SS - Warden #1 115 kV + T-1: Benton 230/115 kV OTHELLO (48307) -> OTHELOSS (48309) CKT 1 at OTHELLO 78.43 319.30 288.17 110.80 N-1: Othello SS - Warden #1 115 kV + T-1: White Bluff #1 230/115 kV OTHELLO (48307) -> OTHELOSS (48309) CKT 1 at OTHELLO 78.43 300.87 288.17 104.41 T-1: Benton 230/115 kV + T-1: White Bluff #1 230/115 kV WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 227.82 353.62 266.08 132.90 406.39 740.27 532.17 278.21 16Hs 16Hw 20Hs 20Hw Staff_PR_135 Attachment C Page 18 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 19 of 52 Table 5: Aggregate sum of percent overloads per facility due to Project #43 Element SumOfPercent WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 372928.20 LIND (48187) -> ROXBORO (48375) CKT 1 at LIND 311787.91 SOTHELOT (48393) -> BENTNAVA (48039) CKT 1 at SOTHELOT 41572.96 OTHELLO (48307) -> OTHELOSS (48309) CKT 1 at OTHELLO 431.85 Staff_PR_135 Attachment C Page 19 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 20 of 52 Mitigating Project Figure 5 presents a one-line diagram showing the facilities for both Avista and the Project #43 developer necessary to interconnect the project and mitigate thermal violations. Figure 5: One-line diagram of Project #43 Staff_PR_135 Attachment C Page 20 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 21 of 52 Project Requirements Point of Interconnection (Lind Station): $7,550,000  Engineering, Management, and Review $50,000  Transmission Line routing $400,000  115 kV terminations, routing, DE’s, Structures $500,000  Property, Permitting, Grading, and Fencing $2,200,000  115 kV Double Bus Double Breaker, 6 Breaker Positions $3,000,000  Control Room, Protection/Integration/SCADA/Comms $1,250,000  Metering and Commissioning $150,000 All of these cost estimates are based on engineering judgment with +/- 20% error in 2016 dollars. It should be noted that property and grading costs can be significantly different than estimated due to site specifics. Detailed cost figures and direct assigned costs versus network upgrade costs will be determined during the Interconnection Facility Study process. Data (RTU) Requirements Data for the operation of the proposed power plant will be needed from the POI station and the 115 kV/ 34.5 kV station. The following data will need to be acquired through a Remote Terminal Unit (RTU):  POI Station o Analogs  Net generation / Interchange MW – real-time  Net generation / Interchange MVAr – real-time  Net generation / Interchange MWh IN – hourly  Net generation / Interchange MWh OUT - hourly  Net generation / Interchange MVarh IN– hourly  Net generation / Interchange MVarh OUT – hourly  Developer 115 kV/34.5 kV Station o Analogs  Real power flow through each of the 34.5 kV feeder breakers  Reactive power flow through each of the 34.5 kV feeder breakers  Reactive power flow from each of the shunt capacitors if applicable  Station Service MW  Station Service MWH - hourly  Individual A, B & C phase voltage on the 115 kV bus o Status  All 34.5 kV and 115 kV breakers  All Unit breakers  Line relay alarm The RTU will need to be dual-ported and independently telemetered to both Transmission Provider Control Centers. In addition, the interchange of real power MW will need to be telemetered to both Transmission Provider Control Centers, independent of the data supplied by the RTU. Staff_PR_135 Attachment C Page 21 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 22 of 52 These data requirements will be examined in greater detail with the completion of an Interconnection Facility Study for Project #43. Transmission Line Requirements: $14,467,000  Lind – Warden 115 kV (21.7 miles) $9,548,000  Othello Switching Station – Warden 115 kV (8.3 miles) $3,652,000  Othello Switching Station – Othello (2.9 miles) $1,267,000 Staff_PR_135 Attachment C Page 22 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 23 of 52 Study Results Incremental Generation Analysis Table 6 presents ATC results when using Avista generation to balance the project, Table 7 presents results with Grand Coulee balancing the project, and Table 8 presents results with Diablo Canyon generation balancing the project. Table 6: ATC with AVA Generation balancing Project #43; 2016 Heavy Summer Projects Case Sink Proj #43 MW Limiting Element Limiting CTG % OTDF AVA 164.01 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Othello SS 115 kV (OSS-SOT) + N-1: Sand Dunes - Warden #2 115 kV 100 AVA 179.67 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Othello SS 115 kV (BENT-SOT) + N-1: Sand Dunes - Warden #2 115 kV 100 AVA 191.39 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Othello SS - Warden #2 115 kV (OSS-L&R)42.93 AVA 191.5 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] BF: A562 Othello SS 115 kV, Othello Switching Station-Warden #2 42.93 AVA 191.61 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R)42.93 AVA 220.73 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Washtucna 115 kV 100 AVA 220.96 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Shawnee 115 kV (LIN-EWN)100 AVA 223.69 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Othello SS - Warden #1 115 kV -32.37 AVA 223.83 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Hatwai - Lolo 230 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 AVA 223.83 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Hatwai - Lower Granite 500 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 AVA 223.95 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Frenchman - Potholes (G) - Sand Dunes 230 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT) 100 AVA 232.67 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: Benton 230/115 kV -22.12 AVA 233.89 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #1 115 kV -22.12 AVA 241 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Washtucna 115 kV 100 AVA 241.81 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Shawnee 115 kV (LIN-EWN)100 AVA 242.82 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Frenchman - Potholes (G) - Sand Dunes 230 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT) 100 AVA 244.6 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Hatwai - Lolo 230 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 AVA 244.7 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Hatwai - Lower Granite 500 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 AVA 244.88 Transformer WEST (48463) TO WEST (48461) CKT 1 [230.00 - 115.00 kV] SUB: Bell 500, 230 & 115 (BPA)8.47 AVA 244.88 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: White Bluff #1 230/115 kV -22.45 AVA 248.39 Line SANDUNES (46087) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Benton - Othello SS 115 kV (OSS-SOT) -100 AVA 250.05 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Sand Dunes - Warden #2 115 kV -35.51 AVA 260.25 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] BF: A308 Warden 115 kV, Othello SS-Warden #2 135.74 AVA 262.02 Line SANSAN11 (90111) TO SANDPT A (48377) CKT 1 [115.00 - 115.00 kV] N-1: Cabinet - Noxon 230 kV + N-1: Cabinet - Rathdrum 230 kV 37.49 AVA 262.09 Line SANDUNES (46087) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Benton - Othello SS 115 kV (BENT-SOT) -100 AVA 263.23 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Othello SS - Warden #1 115 kV 32.37 AVA 281.97 Line BRONX (48047) TO SANDPT A (48377) CKT 1 [115.00 - 115.00 kV] N-1: Cabinet - Noxon 230 kV + N-1: Cabinet - Rathdrum 230 kV -37.49 AVA 286.45 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #1 115 kV 22.12 AVA 286.45 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: Benton 230/115 kV 22.12 AVA 291.77 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Sand Dunes - Warden #2 115 kV 35.51 AVA 293.44 Line OTHELOSS (48309) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden 100 AVA 293.71 Line OTHELOSS (48309) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Sand Dunes - Warden #2 115 kV 100 AVA 295.26 Line BRONX (48047) TO ODEN (48293) CKT 1 [115.00 - 115.00 kV] N-1: Cabinet - Noxon 230 kV + N-1: Cabinet - Rathdrum 230 kV 37.49 Staff_PR_135 Attachment C Page 23 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 24 of 52 Table 7: ATC with Grand Coulee Generation balancing Project #43; 2016 Heavy Summer Projects Case Sink Proj #43 MW Limiting Element Limiting CTG % OTDF Coulee 163.97 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Othello SS 115 kV (OSS-SOT) + N-1: Sand Dunes - Warden #2 115 kV 100 Coulee 179.63 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Othello SS 115 kV (BENT-SOT) + N-1: Sand Dunes - Warden #2 115 kV 100 Coulee 191.32 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Othello SS - Warden #2 115 kV (OSS-L&R)42.95 Coulee 191.42 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] BF: A562 Othello SS 115 kV, Othello Switching Station-Warden #2 42.95 Coulee 191.53 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R)42.95 Coulee 220.73 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Washtucna 115 kV 100 Coulee 220.96 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Shawnee 115 kV (LIN-EWN)100 Coulee 223.81 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Hatwai - Lolo 230 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 Coulee 223.82 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Hatwai - Lower Granite 500 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 Coulee 223.86 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Frenchman - Potholes (G) - Sand Dunes 230 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT) 100 Coulee 226.71 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Othello SS - Warden #1 115 kV -32.03 Coulee 236.83 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: Benton 230/115 kV -21.64 Coulee 239.81 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #1 115 kV -21.64 Coulee 241.62 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Washtucna 115 kV 100 Coulee 241.66 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Frenchman - Potholes (G) - Sand Dunes 230 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT) 100 Coulee 241.83 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Shawnee 115 kV (LIN-EWN)100 Coulee 244.63 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Hatwai - Lolo 230 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 Coulee 244.74 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Hatwai - Lower Granite 500 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 Coulee 245.93 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: White Bluff #1 230/115 kV -22 Coulee 245.93 Line SANDUNES (46087) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Benton - Othello SS 115 kV (OSS-SOT) -100 Coulee 252.23 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Sand Dunes - Warden #2 115 kV -35.17 Coulee 260.18 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] BF: A308 Warden 115 kV, Othello SS-Warden #2 135.74 Coulee 262.03 Line SANDUNES (46087) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Benton - Othello SS 115 kV (BENT-SOT) -100 Coulee 265.72 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Othello SS - Warden #1 115 kV 32.03 Coulee 292.31 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #1 115 kV 21.64 Coulee 292.31 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: Benton 230/115 kV 21.64 Coulee 293.42 Line OTHELOSS (48309) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden 100 Coulee 293.7 Line OTHELOSS (48309) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Sand Dunes - Warden #2 115 kV 100 Coulee 294.33 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Sand Dunes - Warden #2 115 kV 35.17 Staff_PR_135 Attachment C Page 24 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 25 of 52 Table 8: ATC with Diablo Canyon Generation balancing Project #43; 2016 Heavy Summer Projects Case Sink Proj #43 MW Limiting Element Limiting CTG % OTDF Diablo 164.01 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Othello SS 115 kV (OSS-SOT) + N-1: Sand Dunes - Warden #2 115 kV 100 Diablo 179.69 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Othello SS 115 kV (BENT-SOT) + N-1: Sand Dunes - Warden #2 115 kV 100 Diablo 191.46 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Othello SS - Warden #2 115 kV (OSS-L&R)42.92 Diablo 191.57 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] BF: A562 Othello SS 115 kV, Othello Switching Station-Warden #2 42.92 Diablo 191.68 Line WARDEN A (48455) TO WARDEN T (46117) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R)42.92 Diablo 220.74 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Washtucna 115 kV 100 Diablo 220.97 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Shawnee 115 kV (LIN-EWN)100 Diablo 222.15 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Othello SS - Warden #1 115 kV -32.59 Diablo 223.83 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Hatwai - Lolo 230 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 Diablo 223.85 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Hatwai - Lower Granite 500 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 Diablo 223.98 Line LIND (48187) TO ROXBORO (48375) CKT 1 [115.00 - 115.00 kV] N-1: Frenchman - Potholes (G) - Sand Dunes 230 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT) 100 Diablo 228.97 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: Benton 230/115 kV -22.43 Diablo 229.4 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #1 115 kV -22.43 Diablo 241.26 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Frenchman - Potholes (G) - Sand Dunes 230 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT) 100 Diablo 241.66 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Washtucna 115 kV 100 Diablo 241.95 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Shawnee 115 kV (LIN-EWN)100 Diablo 244.72 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Hatwai - Lolo 230 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 Diablo 244.93 Line ROXBORO (48375) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Hatwai - Lower Granite 500 kV + N-1: Devils Gap - Lind 115 kV (LIN-RIT)100 Diablo 245.83 Line SANDUNES (46087) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Benton - Othello SS 115 kV (OSS-SOT) -100 Diablo 245.83 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: White Bluff #1 230/115 kV -22.74 Diablo 248.62 Line LEE&REYN (48308) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Sand Dunes - Warden #2 115 kV -35.73 Diablo 260.28 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] BF: A308 Warden 115 kV, Othello SS-Warden #2 135.74 Diablo 261.62 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Othello SS - Warden #1 115 kV 32.59 Diablo 262.13 Line SANDUNES (46087) TO WARDEN A (48455) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Benton - Othello SS 115 kV (BENT-SOT) -100 Diablo 282.82 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #1 115 kV 22.43 Diablo 282.82 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + T-1: Benton 230/115 kV 22.43 Diablo 290.09 Line LEE&REYN (48308) TO OTHELLO (48307) CKT 1 [115.00 - 115.00 kV] N-1: Othello SS - Warden #1 115 kV + N-1: Sand Dunes - Warden #2 115 kV 35.73 Diablo 293.45 Line OTHELOSS (48309) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden 100 Diablo 293.72 Line OTHELOSS (48309) TO SOTHELOT (48393) CKT 1 [115.00 - 115.00 kV] N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Sand Dunes - Warden #2 115 kV 100 Diablo 305.06 Line BENTNAVA (48039) TO BENTON (40097) CKT 1 [115.00 - 115.00 kV] BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden 100 Staff_PR_135 Attachment C Page 25 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 26 of 52 Thermal Performance Thermal performance results are given in two sections: those results produced by the project additions without Project #43 generating any energy, and those results produced when Project #43 is operating at the maximum requested output of 150 MW. Base Case Impact Projects necessary to interconnect Project #43 clear 28 existing facility thermal violations in the cases used in this study (See Table 9). Table 9: Base Case violations cleared by Mitigating Projects 16HS 16HW 20Hs Proj Proj Proj Row Labels Ref Value Percent Percent Ref Value Percent Percent Ref Value Percent Percent BF: A253 Warden 115 kV, Lind-Warden BENTNAVA (48039) -> SOTHELOT (48393) CKT 1 at BENTNAVA 74.296 270.913 100.49 25.83 BF: A254 Warden 115 kV, Larson-Sand Dunes-Warden BENTNAVA (48039) -> SOTHELOT (48393) CKT 1 at BENTNAVA 74.296 271.24 100.61 25.86 BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden BENTNAVA (48039) -> SOTHELOT (48393) CKT 1 at SOTHELOT 74.296 532.923 197.67 45.35 OTHELOSS (48309) -> OTHELLO (48307) CKT 1 at OTHELLO 80.912 289.992 100.63 25.68 BUS: Warden 115 kV BENTNAVA (48039) -> SOTHELOT (48393) CKT 1 at BENTNAVA 74.296 270.913 100.49 25.83 N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Sand Dunes - Warden #2 115 kV BENTNAVA (48039) -> SOTHELOT (48393) CKT 1 at SOTHELOT 74.296 532.928 197.68 45.35 OTHELOSS (48309) -> OTHELLO (48307) CKT 1 at OTHELLO 80.912 289.995 100.63 25.68 N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 129.746 320.438 120.43 33.3 145.833 369.53 138.88 35.94 N-1: Benton - Midway 230 kV + T-1: White Bluff #1 230/115 kV SOTHELOT (48393) -> BENTNAVA (48039) CKT 1 at SOTHELOT WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 145.833 317.348 119.27 30.6 N-1: Benton - Othello SS 115 kV (BENT-SOT) + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at OTHELOSS 129.746 277.176 104.17 26.79 145.833 285.305 107.22 27.57 N-1: Columbia - Larson 230 kV + N-1: Frenchman - Potholes (G) - Sand Dunes 230 kV BENTNAVA (48039) -> SOTHELOT (48393) CKT 1 at BENTNAVA 171.537 477.016 121.81 45.28 N-1: Columbia - Larson 230 kV + N-1: Potholes - Sand Dunes 230 kV BENTNAVA (48039) -> SOTHELOT (48393) CKT 1 at BENTNAVA 171.537 477.016 121.81 45.28 BENTNAVA (48039) -> SOTHELOT (48393) CKT 1 at SOTHELOT 74.296 273.282 101.37 29.01 N-1: Columbia - Rocky Ford 115 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 145.833 267.825 100.65 26.06 N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 145.833 273.408 102.75 26.57 BaseBaseBase Staff_PR_135 Attachment C Page 26 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 27 of 52 16HS 16HW 20Hs Proj Proj Proj Row Labels Ref Value Percent Percent Ref Value Percent Percent Ref Value Percent Percent N-1: Devils Gap - Stratford 115 kV (STR-WIL) + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 145.833 270.302 101.59 26.3 N-1: Dworshak - Hatwai 500 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 145.833 280.748 105.51 27.31 N-1: Dworshak - Taft 500 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 145.833 279.045 104.87 27.15 N-1: Hatwai - Lower Granite 500 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 145.833 266.584 100.19 25.94 N-1: Larson - Wheeler 230 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 145.833 271.071 101.87 26.38 N-1: Lind - Warden 115 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 129.746 278.623 104.71 28.97 145.833 311.375 117.02 30.2 N-1: Othello SS - Warden #1 115 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) BENTNAVA (48039) -> SOTHELOT (48393) CKT 1 at BENTNAVA 74.296 270.812 100.45 25.82 N-1: Othello SS - Warden #2 115 kV (WAR-L&R) + T-1: Benton 230/115 kV WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 129.746 320.32 120.38 33.29 145.833 369.394 138.83 35.93 N-1: Othello SS - Warden #2 115 kV (WAR-L&R) + T-1: White Bluff #1 230/115 kV WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 129.746 291.004 109.37 30.35 145.833 335.132 125.95 32.6 N-1: Sand Dunes - Wheeler 230 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 145.833 275.464 103.53 26.8 T-1: Benton 230/115 kV + T-1: White Bluff #1 230/115 kV WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 145.833 317.287 119.24 30.6 T-1: Sickler-Douglas #1 500/230 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 145.833 268.854 101.04 26.16 BaseBaseBase Staff_PR_135 Attachment C Page 27 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 28 of 52 Project #43 at Full Requested Output The Transmission System changes recommended by this study clear all facility thermal violations created by Project #43 when it is operating at full requested output. Table 10 presents a sample of facility thermal violations cleared by the proposed projects (values given in Percent Loading). Table 10: Representative sample of Thermal Percent Overloads cleared by proposed projects Ctg / Element 16HsBase 16HsProj 20HsBase 20HsProj N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #2 115 kV (OSS-L&R) LIND (48187) -> ROXBORO (48375) CKT 1 at LIND 232.83 63.16 228.84 62.73 ROXBORO (48375) -> WARDEN A (48455) CKT 1 at ROXBORO 205.49 53.58 199.35 52.82 WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 136.76 39.45 156.9 40.99 N-1: Benton - Midway 230 kV + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) LIND (48187) -> ROXBORO (48375) CKT 1 at LIND 231.11 63.15 228.25 62.81 OTHELOSS (48309) -> OTHELLO (48307) CKT 1 at OTHELLO 74.17 20.42 76.33 21.08 ROXBORO (48375) -> WARDEN A (48455) CKT 1 at ROXBORO 202.34 53.38 198.13 52.61 WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 173.15 50.23 202.6 52.56 N-1: Devils Gap - Lind 115 kV (LIN-RIT) + N-1: Lind - Washtucna 115 kV LIND (48187) -> ROXBORO (48375) CKT 1 at LIND 253.84 69.63 251.49 69.35 OTHELLO (48307) -> OTHELOSS (48309) CKT 1 at OTHELLO 29.83 7.23 28.43 6.85 ROXBORO (48375) -> WARDEN A (48455) CKT 1 at ROXBORO 224.81 59.81 221.32 59.27 WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 88.69 25.45 101.59 25.98 N-1: Othello SS - Warden #1 115 kV + T-1: White Bluff #1 230/115 kV LIND (48187) -> ROXBORO (48375) CKT 1 at LIND 230.72 63.15 227.66 62.82 OTHELLO (48307) -> OTHELOSS (48309) CKT 1 at OTHELLO 93.69 29.11 104.4 29.37 ROXBORO (48375) -> WARDEN A (48455) CKT 1 at ROXBORO 201.61 53.3 196.85 52.59 N-1: Othello SS - Warden #2 115 kV (OSS-L&R) + T-1: Benton 230/115 kV LIND (48187) -> ROXBORO (48375) CKT 1 at LIND 232.87 63.16 228.88 62.73 ROXBORO (48375) -> WARDEN A (48455) CKT 1 at ROXBORO 205.56 53.59 199.43 52.83 WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 136.75 39.45 156.87 40.98 N-1: Othello SS - Warden #2 115 kV (WAR-L&R) + T-1: Benton 230/115 kV LIND (48187) -> ROXBORO (48375) CKT 1 at LIND 231.14 63.15 228.29 62.8 OTHELOSS (48309) -> OTHELLO (48307) CKT 1 at OTHELLO 74.15 20.42 76.3 21.07 ROXBORO (48375) -> WARDEN A (48455) CKT 1 at ROXBORO 202.41 53.38 198.21 52.61 WARDEN A (48455) -> OTHELOSS (48309) CKT 1 at WARDEN A 173.1 50.21 202.55 52.54 Staff_PR_135 Attachment C Page 28 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 29 of 52 Voltage Performance Base Case Voltage Performance There were 3,999 base case low-voltage violations recorded during this study, and the mitigating projects cleared 161 of those violations. Cleared voltage violations are shown in Table 11. Table 11: Voltage violations cleared by mitigating projects Contingency / Bus 16Hs 16Hw 20Hs BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden DELIGHT (47025)0.8484 0.9463 LEE&REYN (48308)0.8695 LIND (48187)0.8505 0.9479 MARENGO (48221)0.8481 0.9459 OTHELLO (48307)0.8702 OTHELOSS (48309)0.8794 RALSTONB (47073)0.8485 0.9462 RITZVILL (48365)0.8384 0.9370 ROXBORO (48375)0.8495 0.9439 SOTHELLO (48391)0.8766 SOTHELOT (48393)0.8809 WARDEN A (48455)0.8683 WASHTUNA (48457)0.8479 0.9459 BUS: Sand Dunes 115 kV DELIGHT (47025)0.9406 LEE&REYN (48308)0.9490 LIND (48187)0.9422 MARENGO (48221)0.9402 OTHELLO (48307)0.9493 RALSTONB (47073)0.9405 RITZVILL (48365)0.9314 0.9464 ROXBORO (48375)0.9381 WASHTUNA (48457)0.9402 N-1: 3TM Larson - Sand Dunes - Warden 115 kV + N-1: Sand Dunes - Warden #2 115 kV DELIGHT (47025)0.8484 0.9483 LEE&REYN (48308)0.8695 LIND (48187)0.8505 0.9499 MARENGO (48221)0.8481 0.9479 OTHELLO (48307)0.8701 OTHELOSS (48309)0.8794 RALSTONB (47073)0.8485 0.9482 RITZVILL (48365)0.8384 0.9390 ROXBORO (48375)0.8495 0.9458 SOTHELLO (48391)0.8766 SOTHELOT (48393)0.8809 WARDEN A (48455)0.8683 WASHTUNA (48457)0.8479 0.9479 N-1: Bell - Coulee #3 230 kV + N-1: Dworshak - Taft 500 kV PINE CRK (48317)1.0086 Staff_PR_135 Attachment C Page 29 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 30 of 52 Contingency / Bus 16Hs 16Hw 20Hs N-1: Benton - Midway 230 kV + N-1: Sand Dunes - Warden #2 115 kV DELIGHT (47025)0.9425 LEE&REYN (48308)0.9488 LIND (48187)0.9442 MARENGO (48221)0.9421 OTHELLO (48307)0.9488 RALSTONB (47073)0.9424 RITZVILL (48365)0.9497 0.9332 ROXBORO (48375)0.9403 WASHTUNA (48457)0.9421 N-1: Benton - Midway 230 kV + S-1: Lind 115kV Switched Shunt RITZVILL (48365)0.9427 N-1: Benton - Othello SS 115 kV (BENT-SOT) + N-1: Othello SS - Warden #2 115 kV (WAR-L&R) LEE&REYN (48308)0.9477 0.9493 OTHELLO (48307)0.9482 0.9499 N-1: Benton - Othello SS 115 kV (BENT-SOT) + S-1: Lind 115kV Switched Shunt DELIGHT (47025)0.9490 0.9428 LIND (48187)0.9444 MARENGO (48221)0.9486 0.9424 RALSTONB (47073)0.9489 0.9427 RITZVILL (48365)0.9399 0.9335 ROXBORO (48375)0.9492 WASHTUNA (48457)0.9486 0.9424 N-1: Benton - Othello SS 115 kV (OSS-SOT) + N-1: Sand Dunes - Warden #2 115 kV DELIGHT (47025)0.9452 LIND (48187)0.9468 MARENGO (48221)0.9448 RALSTONB (47073)0.9451 RITZVILL (48365)0.9460 0.9359 ROXBORO (48375)0.9428 WASHTUNA (48457)0.9448 N-1: Benton - Othello SS 115 kV (OSS-SOT) + S-1: Lind 115kV Switched Shunt RITZVILL (48365)0.9459 N-1: Columbia - Larson 230 kV + N-1: Sand Dunes - Warden #2 115 kV DELIGHT (47025)0.9478 LIND (48187)0.9494 MARENGO (48221)0.9474 RALSTONB (47073)0.9477 RITZVILL (48365)0.9387 ROXBORO (48375)0.9451 WASHTUNA (48457)0.9474 N-1: Dworshak - Taft 500 kV + N-1: Addy - Gifford 115 kV PINE CRK (48317)1.0090 N-1: Dworshak - Taft 500 kV + N-1: Appleway - Ramsey 115 kV PINE CRK (48317)1.0091 N-1: Dworshak - Taft 500 kV + N-1: Lind - Shawnee 115 kV (SHN-EWN) PINE CRK (48317)1.0093 Staff_PR_135 Attachment C Page 30 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 31 of 52 Contingency / Bus 16Hs 16Hw 20Hs N-1: Frenchman - Potholes (G) - Sand Dunes 230 kV + N-1: Sand Dunes - Warden #2 115 kV RITZVILL (48365)0.9438 ROXBORO (48375)0.9500 N-1: Frenchman - Potholes (G) - Sand Dunes 230 kV + S-1: Lind 115kV Switched Shunt RITZVILL (48365)0.9477 N-1: Potholes - Sand Dunes 230 kV + N-1: Sand Dunes - Warden #2 115 kV RITZVILL (48365)0.9438 ROXBORO (48375)0.9500 N-1: Potholes - Sand Dunes 230 kV + S-1: Lind 115kV Switched Shunt RITZVILL (48365)0.9477 N-1: Sand Dunes - Warden #2 115 kV + S-1: Benton 115kV Switched Shunt RITZVILL (48365)0.9458 N-1: Sand Dunes - Warden #2 115 kV + S-1: Larson 115kV Switched Shunt RITZVILL (48365)0.9454 0.9493 N-1: Sand Dunes - Warden #2 115 kV + S-1: Lind 115kV Switched Shunt DELIGHT (47025)0.9263 0.9305 LIND (48187)0.9280 0.9322 MARENGO (48221)0.9259 0.9301 RALSTONB (47073)0.9262 0.9304 RITZVILL (48365)0.9170 ROXBORO (48375)0.9329 0.9372 WASHTUNA (48457)0.9259 0.9300 N-1: Sand Dunes - Warden #2 115 kV + S-1: Othello SS 115kV Switched Shunt DELIGHT (47025)0.9491 MARENGO (48221)0.9487 RALSTONB (47073)0.9490 RITZVILL (48365)0.9400 0.9439 ROXBORO (48375)0.9464 WASHTUNA (48457)0.9487 N-1: Sand Dunes - Warden #2 115 kV + S-1: San Dunes 115kV Switched Shunt DELIGHT (47025)0.9481 LIND (48187)0.9497 MARENGO (48221)0.9477 RALSTONB (47073)0.9481 RITZVILL (48365)0.9390 0.9480 ROXBORO (48375)0.9455 WASHTUNA (48457)0.9478 N-1: Sand Dunes - Warden #2 115 kV + T-1: Benton 230/115 kV DELIGHT (47025)0.9430 LEE&REYN (48308)0.9492 LIND (48187)0.9447 MARENGO (48221)0.9426 OTHELLO (48307)0.9493 RALSTONB (47073)0.9429 RITZVILL (48365)0.9337 ROXBORO (48375)0.9407 WASHTUNA (48457)0.9426 N-1: Sand Dunes - Warden #2 115 kV + T-1: Larson 230/115 kV RITZVILL (48365)0.9480 0.9461 Staff_PR_135 Attachment C Page 31 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 32 of 52 Contingency / Bus 16Hs 16Hw 20Hs N-1: Sand Dunes - Warden #2 115 kV + T-1: Rocky Ford 230/115 kV RITZVILL (48365)0.9494 N-1: Sand Dunes - Warden #2 115 kV + T-1: White Bluff #1 230/115 kV RITZVILL (48365)0.9413 ROXBORO (48375)0.9480 N-1: Shawnee - Thornton 230 kV + T-1: Hatwai 500/230 kV BENEWAH (48037)1.0049 MOSCOW (48249)1.0042 PINE CRK (48317)1.0069 N-1: Walla Walla - Wanapum 230 kV + T-1: Hatwai 500/230 kV BENEWAH (48037)1.0046 PINE CRK (48317)1.0042 S-1: Larson 115kV Switched Shunt + S-1: Lind 115kV Switched Shunt RITZVILL (48365)0.9484 S-1: Lind 115kV Switched Shunt + S-1: Othello SS 115kV Switched Shunt RITZVILL (48365)0.9475 S-1: Lind 115kV Switched Shunt + S-1: San Dunes 115kV Switched Shunt RITZVILL (48365)0.9434 0.9445 S-1: Lind 115kV Switched Shunt + T-1: Benton 230/115 kV RITZVILL (48365)0.9431 S-1: Lind 115kV Switched Shunt + T-1: Larson 230/115 kV RITZVILL (48365)0.9497 S-1: Lind 115kV Switched Shunt + T-1: White Bluff #1 230/115 kV RITZVILL (48365)0.9464 T-1: Hatwai 500/230 kV + T-1: Benewah 230/115 kV PINE CRK (48317)1.0100 Staff_PR_135 Attachment C Page 32 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 33 of 52 Voltage Performance with Project #43 Voltage adequacy studies were performed to determine the theoretical maximum output allowable from Project #43. This maximum output was derived evaluating contingencies and increasing the output from Project #43 (sinking that output into Avista generation) until the voltage collapsed (i.e. the case became numerically unstable). Figure 6 shows all-lines-in-service voltage performance with switched shunts disabled and Project #43 generating no reactive power. This plot shows voltage performance below 0.95 PU when Project #43 output exceeds ~120 MW. Figure 6: Voltage performance with switched shunts disabled and Project #43 generating no reactive power Build Date: August 20, 2015 base case: LIND_115.0 (48187)base case: OTHELLO_115.0 (48307)base case: RITZVILL_115.0 (48365)base case: ROXBORO_115.0 (48375)base case: WARDEN A_115.0 (48455) Nominal Shift 16015515014514013513012512011511010510095908580757065605550454035302520151050 PU V o l t 1 0.99 0.98 0.97 0.96 0.95 0.94 0.93 0.92 0.91 0.9 0.89 0.88 0.87 0.86 0.85 0.84 0.83 Staff_PR_135 Attachment C Page 33 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 34 of 52 Figure 7 shows voltage performance when switched shunts are enabled and Project #43 is generating no reactive power. This plot shows an unacceptable voltage swing as Project #43 generation moves between 40 and 120 MW, after which reactive support switches in to accommodate Project #43 generation increases. Figure 7: Voltage performance with switched shunts enabled and Project #43 generating no reactive power Build Date: August 20, 2015 base case: LIND_115.0 (48187)base case: OTHELLO_115.0 (48307)base case: RITZVILL_115.0 (48365)base case: ROXBORO_115.0 (48375)base case: WARDEN A_115.0 (48455) Nominal Shift 17016516015515014514013513012512011511010510095908580757065605550454035302520151050 PU V o l t 1 0.995 0.99 0.985 0.98 0.975 0.97 0.965 0.96 0.955 0.95 0.945 0.94 0.935 0.93 0.925 0.92 0.915 0.91 0.905 0.9 0.895 0.89 Staff_PR_135 Attachment C Page 34 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 35 of 52 Figure 8 shows adequate voltage performance through the full-range of requested generation up to 150 MW when Project #43 is operated with a 0.95 leading/lagging power factor. Figure 8: Voltage performance with switched shunts enabled and Project #43 generating reactive power at 0.95 leading/lagging. Appendix G to Avista’s Large Generator Interconnection Agreement states, “A wind generating plant shall maintain a power factor within the range of 0.95 leading to 0.95 lagging, measured at the Point of Interconnection as defined in this Agreement, if the Transmission Provider’s System Impact Study shows that such a requirement is necessary to ensure safety or reliability”. This study shows that Project #43 must be operated with a boundary power factor range of 0.95 leading/lagging. Build Date: August 20, 2015 base case: LIND_115.0 (48187)base case: OTHELLO_115.0 (48307)base case: RITZVILL_115.0 (48365)base case: ROXBORO_115.0 (48375)base case: WARDEN A_115.0 (48455) Nominal Shift 24524023523022522021521020520019519018518017517016516015515014514013513012512011511010510095908580757065605550454035302520151050 PU V o l t 1 0.995 0.99 0.985 0.98 0.975 0.97 0.965 0.96 0.955 0.95 0.945 0.94 0.935 0.93 0.925 0.92 0.915 0.91 0.905 0.9 Staff_PR_135 Attachment C Page 35 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 36 of 52 Contingency Voltage Performance The worst case voltage performance during contingencies occurred for a breaker failure (GB1250) within the Sand Dunes station on the Sand Dunes – Warden 115 kV Transmission Line. Figure 9 shows voltage performance for select buses during the contingency with Project #43 generating no reactive power. Figure 9: Worst-case contingent voltage performance with Project #43 generating no reactive power. Build Date: August 20, 2015 BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden: LIND_115.0 (48187)BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden: OTHELLO_115.0 (48307) BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden: RITZVILL_115.0 (48365)BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden: ROXBORO_115.0 (48375) BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden: WARDEN A_115.0 (48455) Nominal Shift 11010810610410210098969492908886848280787674727068666462605856545250484644424038363432302826242220181614121086420 PU V o l t 0.985 0.98 0.975 0.97 0.965 0.96 0.955 0.95 0.945 0.94 0.935 0.93 0.925 0.92 0.915 0.91 0.905 0.9 0.895 0.89 0.885 0.88 0.875 0.87 0.865 0.86 0.855 0.85 Staff_PR_135 Attachment C Page 36 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 37 of 52 Figure 10 shows adequate voltage performance during the worst-case contingency when Project #43 is operated with a 0.95 leading/lagging power factor. Figure 10: Worst-case contingent voltage performance with Project #43 generating 0.95 PU leading/lagging power factor Build Date: August 20, 2015 BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden: LIND_115.0 (48187)BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden: OTHELLO_115.0 (48307) BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden: RITZVILL_115.0 (48365)BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden: ROXBORO_115.0 (48375) BF: GB1250 Sand Dunes 115 kV, Larson-Sand Dunes-Warden: WARDEN A_115.0 (48455) Nominal Shift 18518017517016516015515014514013513012512011511010510095908580757065605550454035302520151050 PU V o l t 0.992 0.99 0.988 0.986 0.984 0.982 0.98 0.978 0.976 0.974 0.972 0.97 0.968 0.966 0.964 0.962 0.96 0.958 0.956 0.954 0.952 0.95 0.948 0.946 0.944 0.942 0.94 0.938 0.936 0.934 0.932 0.93 0.928 0.926 0.924 0.922 0.92 0.918 0.916 Staff_PR_135 Attachment C Page 37 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 38 of 52 Impacted Transmission Facilities A preliminary sensitivity analysis was performed in order to determine the transmission elements affected by the proposed Project #43 interconnection. This analysis was completed through the use of the Power Transfer Distribution Factor (PTDF) tool within PowerWorld Simulator. The point of receipt (POR) modeled was the Project #43 generation facility. The selection of the point of delivery (POD) presumes an assumption on where the energy from the interconnecting project is delivered therefore yielding different sensitivity results. This study analyzed two PODs: 1. All generators owned and/or operated by Avista, excluding Project #43 (Table 12 representing the interconnecting project as a network resource for Network Resource Interconnection Service) 2. All generators in the Western Interconnection excluding those owned and/or operated by Avista (Table 13 representing an energy resource for Energy Resource Interconnection Service). These studies do not cover all possibilities of where the energy from the interconnecting project may be scheduled, but they do provide a strong indication of what transmission elements are affected. Common elements showing sensitivity with different POD assumptions indicate transmission elements that should be monitored closely and may indicate other Affected Systems. Avista coordinated this study work with the following noted Affected Systems:  Bonneville Power Administration  Grant County PUD Staff_PR_135 Attachment C Page 38 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 39 of 52 Table 12: PTDF with Avista Generation balancing Project #43 From Number From Name To Number To Name Circuit % PTDF From Nom kV (Max) Nom kV (Min) Owner Name From Owner Name To 48187 LIND 48375 ROXBORO 1 92.86 115 115 Avista Corp.Avista Corp. 48375 ROXBORO 48455 WARDEN A 1 89.51 115 115 Avista Corp.Avista Corp. 48455 WARDEN A 46117 WARDEN T 1 26.93 115 115 Avista Corp.Grant PUD 46119 WHEEL TI 46121 WHEEL TP 1 26.91 115 115 Grant PUD Grant PUD 46130 BASS JCT 46119 WHEEL TI 1 26.87 115 115 Grant PUD Grant PUD 46043 MAE VL T 46166 POTHOLEG 1 22.53 230 230 Grant PUD Grant PUD 48309 OTHELOSS 48393 SOTHELOT 1 21.45 115 115 Avista Corp.Avista Corp. 48039 BENTNAVA 40097 BENTON 1 20.68 115 115 Avista Corp.Bonneville Power Admin 46300 ROCKYFDG 46299 NQUINCYT 1 20.59 230 230 Grant PUD Grant PUD 46151 LARSON 46300 ROCKYFDG 1 20.53 230 230 Grant PUD Grant PUD 40091 BELL BPA 40092 BELL S4 1 20.03 500 230 Bonneville Power Admin Bonneville Power Admin 46166 POTHOLEG 40851 POTHOLES 1 17.22 230 230 Grant PUD Bonneville Power Admin 41346 MIDWAYB1 41347 MIDWAYB2 BS 16.07 230 230 Bonneville Power Admin Bonneville Power Admin 40553 HOT SPR 40551 HOT SPR 1 13 500 230 Bonneville Power Admin Bonneville Power Admin 46039 LARSON 46155 ROCKYFD 1 11.82 115 115 Grant PUD Grant PUD 48281 NOXON 48285 NOXON12 1 11.62 230 14.4 Avista Corp.Avista Corp. 90011 BELLAN11 40624 LANCASTR 1 11.1 230 230 Bonneville Power Admin Bonneville Power Admin 40090 BELL S3 90011 BELLAN11 1 11.06 230 230 Bonneville Power Admin Bonneville Power Admin 40369 DWORSHAK 40521 HATWAI 1 -10.03 500 500 Bonneville Power Admin Bonneville Power Admin 47031 DOUGLAS 46833 ROCKYRH3 1 -10.54 230 230 Douglas PUD Chelan PUD 46151 LARSON 46039 LARSON 1 -11.09 230 115 Grant PUD Grant PUD 48309 OTHELOSS 48455 WARDEN A 1 -12.02 115 115 Avista Corp.Avista Corp. 40973 SICKLER 47031 DOUGLAS 1 -12.18 500 230 Bonneville Power Admin Douglas PUD 41113 VANTAGE 41112 VANTAGES 1 -12.33 500 230 Bonneville Power Admin Bonneville Power Admin 41111 VANTAGEN 46169 WANAPUM 1 -12.43 230 230 Bonneville Power Admin Grant PUD 41113 VANTAGE 41111 VANTAGEN 2 -12.54 500 230 Bonneville Power Admin Bonneville Power Admin 40553 HOT SPR 41057 TAFT 1 -13 500 500 Bonneville Power Admin Bonneville Power Admin 40499 HANFORD 41113 VANTAGE 1 -17.77 500 500 Bonneville Power Admin Bonneville Power Admin 40521 HATWAI 40679 LOW GRAN 1 -18.16 500 500 Bonneville Power Admin Bonneville Power Admin 48039 BENTNAVA 48393 SOTHELOT 1 -20.68 115 115 Avista Corp.Avista Corp. 46298 WQUINCYT 46299 NQUINCYT 1 -20.69 230 230 Grant PUD Grant PUD 40261 COLUMBIA N 46298 WQUINCYT 1 -20.77 230 230 Bonneville Power Admin Grant PUD 46043 MAE VL T 46089 SANDUNES 1 -22.53 230 230 Grant PUD Grant PUD 40288 COULE R1 40287 COULEE 6 -24.02 500 500 Bonneville Power Admin USBR 40091 BELL BPA 40288 COULE R1 6 -24.06 500 500 Bonneville Power Admin Bonneville Power Admin 46039 LARSON 46121 WHEEL TP 1 -25.53 115 115 Grant PUD Grant PUD 46091 SCHRAG T 46117 WARDEN T 1 -26.84 115 115 Grant PUD Grant PUD 46085 RUFF TP 46091 SCHRAG T 1 -26.85 115 115 Grant PUD Grant PUD 46130 BASS JCT 46085 RUFF TP 1 -26.87 115 115 Grant PUD Grant PUD 46089 SANDUNES 46087 SANDUNES 1 -31.92 230 115 Grant PUD Grant PUD 46087 SANDUNES 48455 WARDEN A 1 -37.52 115 115 Grant PUD Avista Corp. 48187 LIND 48362 RATTFLT_SUB 1 -92.86 115 115 Avista Corp.First Wind Staff_PR_135 Attachment C Page 39 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 40 of 52 Table 13: PTDF with All WECC Generation (minus AVA gen) balancing Project #43 From Number From Name To Number To Name Circuit % PTDF From Nom kV (Max) Nom kV (Min) Owner Name From Owner Name To 48187 LIND 48375 ROXBORO 1 92.86 115 115 Avista Corp.Avista Corp. 48375 ROXBORO 48455 WARDEN A 1 89.51 115 115 Avista Corp.Avista Corp. 48455 WARDEN A 46117 WARDEN T 1 26.9 115 115 Avista Corp.Grant PUD 46119 WHEEL TI 46121 WHEEL TP 1 26.88 115 115 Grant PUD Grant PUD 46130 BASS JCT 46119 WHEEL TI 1 26.84 115 115 Grant PUD Grant PUD 46043 MAE VL T 46166 POTHOLEG 1 22.51 230 230 Grant PUD Grant PUD 48309 OTHELOSS 48393 SOTHELOT 1 21.51 115 115 Avista Corp.Avista Corp. 48039 BENTNAVA 40097 BENTON 1 20.74 115 115 Avista Corp.Bonneville Power Admin 46300 ROCKYFDG 46299 NQUINCYT 1 20.58 230 230 Grant PUD Grant PUD 46151 LARSON 46300 ROCKYFDG 1 20.53 230 230 Grant PUD Grant PUD 46166 POTHOLEG 40851 POTHOLES 1 16.88 230 230 Grant PUD Bonneville Power Admin 41346 MIDWAYB1 41347 MIDWAYB2 BS 16.13 230 230 Bonneville Power Admin Bonneville Power Admin 30055 GATES 30073 GATMID11 1 12.88 500 500 Pacific Gas and Electric Pacific Gas and Electric 30073 GATMID11 30060 MIDWAY 1 12.88 500 500 Pacific Gas and Electric Pacific Gas and Electric 46039 LARSON 46155 ROCKYFD 1 11.69 115 115 Grant PUD Grant PUD 40837 PONDROSA 90099 PONSUM11 1 11.45 500 500 Bonneville Power Admin Bonneville Power Admin 90099 PONSUM11 90100 PONSUM12 1 11.32 500 500 Bonneville Power Admin Bonneville Power Admin 90100 PONSUM12 90101 PONSUM13 1 11.32 500 500 Bonneville Power Admin Bonneville Power Admin 90101 PONSUM13 90102 PONSUM14 1 11.23 500 500 Bonneville Power Admin Bonneville Power Admin 90102 PONSUM14 41043 SUMMER L 1 11.21 500 500 Bonneville Power Admin Bonneville Power Admin 30050 LOSBANOS 30070 LOSMID11 1 11.04 500 500 Pacific Gas and Electric Pacific Gas and Electric 30070 LOSMID11 30071 LOSMID12 1 10.99 500 500 Pacific Gas and Electric Pacific Gas and Electric 30071 LOSMID12 30072 LOSMID13 1 10.99 500 500 Pacific Gas and Electric Pacific Gas and Electric 30072 LOSMID13 30060 MIDWAY 1 10.99 500 500 Pacific Gas and Electric Pacific Gas and Electric 40489 GRIZZLY 40488 GRIZZ R3 1 10.95 500 500 Bonneville Power Admin Bonneville Power Admin 40488 GRIZZ R3 40837 PONDROSA 1 10.94 500 500 Bonneville Power Admin Bonneville Power Admin 30040 TESLA 30050 LOSBANOS 1 10.31 500 500 Pacific Gas and Electric Pacific Gas and Electric 40061 ASHE 40499 HANFORD 1 -10.19 500 500 Bonneville Power Admin Bonneville Power Admin 46151 LARSON 46039 LARSON 1 -11.1 230 115 Grant PUD Grant PUD 40973 SICKLER 47031 DOUGLAS 1 -11.38 500 230 Bonneville Power Admin Douglas PUD 48309 OTHELOSS 48455 WARDEN A 1 -12.06 115 115 Avista Corp.Avista Corp. 41113 VANTAGE 41112 VANTAGES 1 -12.28 500 230 Bonneville Power Admin Bonneville Power Admin 41111 VANTAGEN 46169 WANAPUM 1 -12.38 230 230 Bonneville Power Admin Grant PUD 41113 VANTAGE 41111 VANTAGEN 2 -12.49 500 230 Bonneville Power Admin Bonneville Power Admin 40499 HANFORD 41113 VANTAGE 1 -18.95 500 500 Bonneville Power Admin Bonneville Power Admin 46298 WQUINCYT 46299 NQUINCYT 1 -20.69 230 230 Grant PUD Grant PUD 48039 BENTNAVA 48393 SOTHELOT 1 -20.74 115 115 Avista Corp.Avista Corp. 40261 COLUMBIA N 46298 WQUINCYT 1 -20.76 230 230 Bonneville Power Admin Grant PUD 46043 MAE VL T 46089 SANDUNES 1 -22.51 230 230 Grant PUD Grant PUD 46039 LARSON 46121 WHEEL TP 1 -25.48 115 115 Grant PUD Grant PUD 46091 SCHRAG T 46117 WARDEN T 1 -26.81 115 115 Grant PUD Grant PUD 46085 RUFF TP 46091 SCHRAG T 1 -26.82 115 115 Grant PUD Grant PUD 46130 BASS JCT 46085 RUFF TP 1 -26.84 115 115 Grant PUD Grant PUD 46089 SANDUNES 46087 SANDUNES 1 -31.89 230 115 Grant PUD Grant PUD 46087 SANDUNES 48455 WARDEN A 1 -37.49 115 115 Grant PUD Avista Corp. 48187 LIND 48362 RATTFLT_SUB 1 -92.86 115 115 Avista Corp.First Wind Staff_PR_135 Attachment C Page 40 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 41 of 52 Short Circuit Analysis General: The proposed Project #43 Wind generation is 150 MW in size and approximately 16 miles from the Lind 115 kV bus. For the purposes of the System Protection System Impact Study, Project #43 wind generation POI will be at the Lind 115kV bus. The assumptions for the Project #43 model are: 1. The facility topology of collector strings to station GSU transformers was provided by Project #43. An equivalent collector system per Table 1 of WECC Wind Power Plant Power Flow Modeling Guide 2008 was used. 2. 1 – 158.3 MVA wye-wye-delta 3 winding transformer 115/34.5/13.8 kV step up with 9.5% impedance and an X/R ratio of 37.6. 3. 65 - Parallel 1.9MVA pad mount delta-wye 0.69/34.5 kV GSU transformers stepping up the generation to a 34.5 kV collector system. The pad-mounted transformer positive- sequence impedance is 9% on the transformer MVA base, with X/R ratio of 10. The pad- mounted transformer zero-sequence impedance is 8.5% on the transformer MVA base, with X/R ratio of 10.6. 4. 65 - 2.3 Megawatt Type 4 machines providing approximately 1 per unit fault current at 26 degrees. 5. The 115kV interconnection transmission line was modeled as 12 miles of 795 ACSR conductor. The feasibility study assumption was 16 miles of conductor. Staff_PR_135 Attachment C Page 41 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 42 of 52 ASPEN Model Development: Station Transformers The 115/34.5/13.8 kV 158.3 MVA wye-wye-delta three-winding transformer was modeled using data provided by Project #43. The impedances are as follows: Windings MVA Base R+ (p.u.) X+ (p.u.) Z+ (p.u.) R0 (p.u.) X0 (p.u.) Z0 (p.u.) ZP-S 100.0 0.001595 0.059979 0.060000 0.001436 0.053981 0.054000 ZS-T 100.0 0.000853 0.022184 0.022200 0.000768 0.019965 0.019980 ZP-T 100.0 0.003696 0.096103 0.096174 0.003327 0.086493 0.086557 Collector String and Pad Mount GSUs The impedances were converted a 100 MVA base is as follows: Collector string The collector string equivalent line parameters were based on information provided by Project #43. Project #43 used the ‘WECC Guide for Representation of Photovoltaic Systems in Large- Scale Load-Flow Simulations’ (January 2011) as the method to determine the line parameters. The positive and zero-sequence impedances are shown below: R1 (pu) X1 (pu) R0 (pu) X0 (pu) Bc Capacitive Susceptance (pu) 0.01104 0.00960 0.03833 0.00627 0.0458477 Pad Mount GSU – 65 units parallel The positive and zero-sequence impedances were calculated using data provided by Project #43. Staff_PR_135 Attachment C Page 42 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 43 of 52 Wind Turbines The generators for Project #43 were modeled as a single 150 MVA machine the equivalence of 65 – 2.3 MVA wind generators. The wind turbines were identified as Type IV. Type IV turbines typically will not provide more than 1 per unit short circuit contribution at an angle of approximately 26 degrees into the system. The wind turbine model used the worst case scenario with all machines on line (150 MVA). Since the WTG transformer is a Wye-Delta blocking the negative and zero sequence contributions to a single line to ground 115 kV transmission fault, all sequence parameters were set equal. The subtransient, transient and synchronous impedances were all set the same. The 150 MVA machine parameters are as follows: Fault Analysis Study A short circuit analysis study was performed to determine if Avista’s installed equipment is adequate for the proposed Project #43 POI. The following analysis was performed: 1. Perform 3LG and SLG close-in faults on each line terminal breaker at affected buses by the interconnection. 2. Perform 3LG and SLG close-in faults on each bus affected by the interconnection 3. Compare resulting fault duties to breaker or power fuse interrupt ratings. Fault Duty Comparisons The changes in fault duties in amperes due to the addition of the Project #43 150 MW of generation networked to the Lind bus are shown below. Staff_PR_135 Attachment C Page 43 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 44 of 52 System Location 3LG w/out Generation 3LG with Generation Percent Change 1LG w/out Generation 1LG with Generation Percent Change Lind Bus 4033 4384 9% 2621 3873 48% Lind/ Shawnee Terminal 3137 3491 11% 2074 3484 68% Lind/ Devils Gap Terminal 3180 3533 11% 2020 3446 71% Lind/ Warden Terminal 1749 2142 22% 1148 2827 146% Lind/ Washtucna Terminal 4033 4384 9% 2621 3873 48% Lind 115/13 kV Transformer 4033 4384 9% 2621 3873 48% Washtucna 115 kV Bus 1533 1533 0% 957 1049 10% Ritzville 115 kV Bus 2900 2955 2% 1896 2149 13% Ralston 115 kV Bus 2987 3052 2% 1895 2174 15% Roxboro 115 kV Bus 4937 5094 3% 3205 3747 17% Delight 115 kV Bus 2219 2268 2% 1401 1648 18% Marengo 115 kV Bus 2858 2892 1% 1809 2001 11% Staff_PR_135 Attachment C Page 44 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 45 of 52 Station Breaker/Device Ratings - The three-phase and single line to ground fault magnitudes increased in the area as expected. The Lind 115 kV breaker ratings are 40 kA symmetrical interrupt. The 115 kV power fuses at Marengo, Washtucna, Ritzville and Lind are rated at 10,000 kA interrupt. The Mark III circuit switcher rating at Roxboro is 6000/3000 interrupt. The fault duty at the Roxboro 115 kV bus is approximately 85% of the circuit switcher capability. The interrupting devices at Ralston and Delight are not Avista assets so are not included in this study. Summary Integrating Project #43 Wind generation of 150 MW onto Avista’s 115 kV system increased fault duties in the Big Bend area. The increased fault duties are well below the interrupting capability of the breakers. The results show integrating Project #43 Wind generation onto Avista’s 115 kV system at the requested POI will not impact the capability of the Lind substation line breakers to interrupt three phase or single phase faults. Non-Avista facilities in the area affected by the fault duties increase should be reviewed by the facility owner. All transmission and distribution relay settings will require a review and coordination verification for the Big Bend area. Staff_PR_135 Attachment C Page 45 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 46 of 52 Transient Stability Method and Criteria The case primarily used for stability analysis was the 2020 Heavy Summer Case, and the Project #43 developer provided dynamic models and data for the facilities added to the base cases. Over 800 contingencies3 were analyzed using the contingency analysis capabilities within PowerWorld Simulator, and 44 of these contingencies local to Project #43 were further analyzed in the 2020 Light Summer case as a further check on project performance. This software tool fully models Remedial Actions Schemes (RAS) and automatically “arms” and applies RAS as the modeled system conditions dictate. Each scenario was modeled out to 10 seconds. Historic WECC and Avista requirements for disturbance performance were used to evaluate the results of the dynamic stability analysis. These requirements are as follows:  System must remain stable.  Maximum allowable transient voltage dip of 25 percent at load buses or 30 percent at non-load buses.  Maximum allowable transient voltage dip not to exceed 20 percent for more than 20 cycles at load buses.  Minimum allowable frequency of 59.6 Hz for 6 cycles or more at load buses.  Maximum allowable post-transient voltage deviation of 5 percent from pre-disturbance voltage. A detailed explanation of performance criteria can be referenced in the WECC TPL – (001 thru 004) – WECC – 1 – CR – System Performance Criteria. 3 Avista contingency analysis development is documented in Avista Standard TP-SPP-06 Contingency Analysis Staff_PR_135 Attachment C Page 46 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 47 of 52 Transient Stability Results Transient Stability performance of Project #43 as modeled in the cases used for this study was found to be adequate; no stability violations were noted. Figure 11 provides an example response of the system in the 2020 Light Summer case during a breaker failure event on the Othello Switching Station – Warden 115 kV Transmission Line. Figure 11: Stability plots for select facilities in the 20 Light Sumer case during the BF: A255 @ Othello Switching Station event Staff_PR_135 Attachment C Page 47 of 52 LGIP #43 System Impact Study Report PROJECT #43 October 27, 2015 Page 48 of 52 Figure 12: Stability plots for Project #43 power in the 20 Light Sumer case during the BF: A255 @ Othello Switching Station event Staff_PR_135 Attachment C Page 48 of 52 Note for Project #43 Developer: General utility practice does not allow single generation plants to serve as the only source of power in an island, and there exists the potential, either by contingency or maintenance, for Project #43 to become islanded. Figure 13 shows the Avista Transmission System local to Project #43, and the image shows the two transmission line segments east of Lind Station that are operated normally open result in Project #43 operating radially from Lind to Warden stations . Given this configuration, Project #43 will need to be tripped for any outage that interrupts the transmission connection between Lind and Warden stations. While the stability models provided by the Developer did trip the plant for all faults studied that island the plant, Avista would likely employ and explicit tripping scheme for anti-islanding protection. Figure 13: Transmission System local to Project #43 Staff_PR_135 Attachment C Page 49 of 52 Conclusion The study work indicates that this interconnection performs adequately and has no adverse impacts on the Transmission System when the identified network upgrades are completed. The estimated cost to fully interconnect Project #43 is approximately $22,017,000. This includes the rebuilding Lind Station and the increase in capacity of local transmission lines. The scheduled interconnection of Project #43 is dependent on the completion of a Facilities Study, Engineering and Procurement Agreement, and Interconnection Agreement. POI Project Output Schedule Total Cost ($000) Lind Station 150 MW Time to Construct = December 31, 2018 $22,017,000 All construction costs are in 2016-year dollars and are based on engineering judgment with +/- 20% error. These cost estimates assume that the Project #43 owners are responsible for all necessary facilities from their facility to the POI. Operationally the output of Project #43 would have to be curtailed in the event of planned or extended forced outages on any transmission line segment between the Lind 115kV Switching Station and Warden 115kV Switching Station. In the event the two 115kV transmission lines east of Lind are operated closed, they each have maximum thermal loading restrictions of 53MW. Other transmission outages may require the curtailment of project output as well. A complete analysis of any transmission capacity impacts and any facilities needed to mitigate such impacts would be identified through the study process for Transmission Service, once a request for Transmission Service has been made. Staff_PR_135 Attachment C Page 50 of 52 Appendix A ASPEN Model Development: The following shows the calculations and assumptions used for the 115kV transmission line parameters. Option 1 Given Z+ 115kv=0.00097 0.00538 ohms/mi for 795ACSR115HF then Z0/Z+ = 3.72 Z0 115kV = 0.00313 0.02011 ohms/mi using the Z0/Z+ ratio then for each line in Option 1: Miles LGIR43-LIN Z+ 16 0.01415 0.086780 Z0 0.05264 0.32282 LIN - ROX Z+0.00955 0.05859 Z0 0.03553 0.21794 ROX - WAR Z+0.01275 0.07819 Z0 0.04743 0.290867 WAR - GCPUD Z+0.00170 0.00940 Z0 0.00632 0.034968 WAR - OSS Z+0.03448 0.05336 Z0 0.12827 0.198499 Staff_PR_135 Attachment C Page 51 of 52 Option 2 Given Z+ 115kv=0.00097 0.00538 ohms/mi for 795ACSR115HF then Z0/Z+ = 3.72 Z0 115kV = 0.00313 0.02011 ohms/mi using the Z0/Z+ ratio then for each line in Option 2: Miles RAL - HIL Z+ 5 0.005308 0.032547 Z0 0.01975 0.12107 LGIR43-RAL Z+ 9 0.005308 0.032547 Z0 0.01975 0.12107 HIL - MAR Z+ 5.5 0.00487 0.02984 Z0 0.01812 0.11100 MAR - EW Z+ 22.8 0.02016 0.12364 Z0 0.07500 0.459941 EW - DIA Z+ 24.3 0.01265 0.07756 Z0 0.04706 0.288523 DIA - SHN Z+ 17.6 0.01556 0.09545 Z0 0.05788 0.355074 LIN - RITZ Z+ 16.8 0.01486 0.09112 Z0 0.05528 0.338966 RITZ - SPR Z+ 18.8 0.01662 0.10196 Z0 0.06183 0.379291 SPR - GAF Z+ 6.3 0.00557 0.03418 Z0 0.02072 0.12715 GAF - REAR Z+ 18 0.01592 0.09762 Z0 0.05922 0.363146 REAR - DGP Z+ 13.9 0.01229 0.07539 Z0 0.04572 0.280451 Staff_PR_135 Attachment C Page 52 of 52