Rocky Mountain Power Sub Transmission Five Year Study Findings and Kick Off Attachment K Meeting September 10, 2015

© 2000 PACIFICORP | PAGE 2 Rocky Mountain Power Area Transmission Planning Area Transmission Planning Manager: Mark Adams Area Transmission Engineers: Planning Engineers Bhavana Katyal Talmage Daley Jeremy Viula Nathan Wilson Studies Engineers Scott Murdock Nicole DeGiulio

© 2000 PACIFICORP | PAGE 3 Why Prepare the Studies? –FERC/WECC required –Provides a good round map for future –Provides justification for new system additions

© 2000 PACIFICORP | PAGE 4 Who is invited? –Any individual is welcome –City and Municipal officials –Generation producers –Large industrial users –Equipment producers

© 2000 PACIFICORP | PAGE 5 Third Party Contributions –Load and Forecast Projects –New Points of Delivery –System Power Flow Model –Anticipated Future System Upgrades  Including block load increases

© 2000 PACIFICORP | PAGE 6 Basic Understanding of the Study –Field Study  Document equipment  Verify system ratings and settings –Identify System Problems & Future Recommendations –Generate a Report  Brief Understanding of the Area  List Equipment ratings  Fault duties, operation schemes  Lists system “Problems and Future Recommendations”

© 2000 PACIFICORP | PAGE 7 Study Restrictions –CIPS  The reliability of the energy grid depends not only on physical assets, but cyber assets. The North American Electric Reliability Corporation (NERC) realized that, along with protecting the physical assets, Critical Cyber Assets also need to be protected to keep the energy grid secure. –Confidentiality

© 2000 PACIFICORP | PAGE 8 Study Areas for 2015 Findings Reports Goshen – Scott Murdock

© 2000 PACIFICORP | PAGE 9 GOSHEN AREA STUDY Bhavana Katyal / Scott Murdock/ Need to review the LOADS before Friday

© 2000 PACIFICORP | PAGE 10 Goshen STUDY The Goshen service area encompasses approximately 5600 square miles spanning portions of nine counties in East Idaho. The Rocky Mountain Power (RMP) portion of this area is serviced by 56 transmission and distribution substations

© 2000 PACIFICORP | PAGE 11 Goshen Study Map

© 2000 PACIFICORP | PAGE 12 Goshen STUDY –Rocky Mountain Power (RMP) –Bonneville Power Administration (BPA) –PacifiCorp Energy Supply Management (ESM) –PacifiCorp Transmission (PT) –Idaho Power Company (IPC) –Utah Associated Municipal Systems (UAMPS) Municipalities/REAs: –Idaho Falls City –Fall River, Lost River, Salmon River and Lower Valley Energy

© 2000 PACIFICORP | PAGE 13 Goshen Study –There are 10 transmission subs: Amps, Antelope, Big Grassy, Bonneville, Goshen, Rigby, Jefferson, St. Anthony, Scoville, and Sugarmill –Transmission voltages studied include 230, 161, 138, 69 and 46 kV. –There are 11 transmission line that go in/out of the area at voltage levels of 345, 230, 161 and 115 kV

© 2000 PACIFICORP | PAGE 14 Goshen STUDY

© 2000 PACIFICORP | PAGE 15 Goshen STUDY Transmission Lines in/out of the Goshen Area Line Name Line Voltage (kV) Line Configuration Ownership Line Conductor Size Line Length (Miles) Goshen - Kinport 345 LoopRMP ACSR41 Goshen - Three Mile KnollLoopIPC ACSR52.82 Antelope - Anaconda (Mill Creek) 230 Loop RMP/NorthWestern Energy ACSR200 Antelope - BradyIPC ACSR58 Antelope - Lost RiverRadialRMP/BPA ACSR31.42 Goshen - Blackfoot 161Loop IPC ACSR19 Goshen - DrummondBPA ACSR~60 Goshen - Fishcreek - GraceRMP HHCU57.22 Goshen - Jefferson - Big Grassy Anaconda (Mill Creek) IPC/NorthWestern Energy HHCU Goshen - Swan ValleyBPA ACSR47 Goshen - Palisades115LoopBPA ACSR51.71

© 2000 PACIFICORP | PAGE 16 Load Growth –Base System Loads  Summer 2014: 652 MW  Winter : 383 MW –Growth  Summer: 1.6%  Winter: 2.2% –Projected System Loads  Summer 2019: 716 MW  Winter : 443 MW

© 2000 PACIFICORP | PAGE 17 Goshen STUDY –System Improvements  10 items to maintain company standards  6 items of a risk management nature

© 2000 PACIFICORP | PAGE 18 Increase Capacity Remove regulators and Replace with a new 30 MVA kV LTC transformer System Improvements Sandune kV Substation Increase Capacity from 22.4 to 30 MVA 2015

© 2000 PACIFICORP | PAGE 19 –Improve Voltage Control at Arco System Improvements 2015

© 2000 PACIFICORP | PAGE System Improvements –Correct Clearance Issues (Jefferson to Big Grassy) –Increase Capacity (Goshen to Jefferson)

© 2000 PACIFICORP | PAGE 21 System Improvements Upgrade Belson regulators replace 416 kVA units with 509 kVA units 2017

© 2000 PACIFICORP | PAGE 22 System Improvements Increase capacity on Sand Creek Tap 2018

© 2000 PACIFICORP | PAGE 23 System Improvements 2018

© 2000 PACIFICORP | PAGE 24 System Improvements Mud Lake kV Substation Increase Regulator Capacity from 416 to 509 kVA 2019

© 2000 PACIFICORP | PAGE 25 System Improvements Upgrade Rexburg #2 regulators to 509 kVA 2019

© 2000 PACIFICORP | PAGE 26 System Improvements –Upgrade Ammon regulator to 509 kVA –Upgrade fuses to 175E 2019

© 2000 PACIFICORP | PAGE 27 Construction Schedule Summary Construction Schedule ~ Projects Required to Maintain Company Standards 2015 Construction - In service by end of this year 7-1Sandune Change out transformer. The existing unit has heating issues.this will also increase capacity $1,432, ArcoRemove damaged regulators: Install kVA regulators$350, Construction - In service before May 1 of this year 7-3 Jefferson-Big Grassy 161 kV line Correct clearance issues$918, Construction - In service before May 1 of this year 7-4 Goshen-Jefferson 161 kV line Rebuild 29.5 line miles with 795 ACSR conductor$15,968, BelsonReplace overloaded regulators with 509 kVA units$350, Construction - In service before May 1 of this year 7-6Sand Creek 69 kV lineIncrease capacity:Rebuild 3.2 miles with 795 ACSR$3,680, Sugar CityVoltage Improvement: Install 2 stage 24 Mvar capacitor$3,531, Construction - In service before May 1 of this year 7-8Mud Lake SubReplace overloaded regulators with 509 kVA units$350, Rexburg Bank #2Replace overloaded regulators with 509 kVA units$350, AmmonReplace overloaded regulators with 509 kVA units$350,000 Grand Total $27,279,000

© 2000 PACIFICORP | PAGE 28 Goshen STUDY