1. 1 CCPG Senate Bill 100 Lamar – Front Range Presentation May 27, 2010

2. 2 Senate Bill 100 requires Designate “Energy Resource Zones” Develop plans for expansion of transmission for delivering power from beneficial energy resource in or near such zones Submit proposed projects for CPCN Senate Bill 07-100

3. 3 New Lamar- Comanche 345 kV & Lamar - Missile Site 345 kV ISD 2016 New San Luis Valley- Calumet-Comanche 230 & 345 kV lines ~ ISD 2013 New Midway-Waterton 345 kV ~ISD 2011 New Lamar –Vilas 345 kV ISD 2016 New Pawnee-Daniels Park 345 kV -2 nd circuit ~ISD 2016 New Missile Site 230 kV ISD 2010) & 345 kV (ISD 2013) New Ault-Cherokee 230 kV ~ISD 2015 New Pawnee-Smoky Hill 345 kV, ISD 2013 2009 SB-100 Transmission Plan

4. 4 *Generation values are not simultaneous ItemProjectGeneration (MW)* In Service Date* Project StatusMileage (kV,mi) 1.Missile Site 230kV Switching Station25012/10Project Initiated, no CPCN necessary n/a 2.Midway-Waterton 345kV Transmission Project 6/11CPCN confirmed May 2009345, 82 3.Pawnee-Smoky Hill 345kV Transmission project 5006/13CPCN granted Feb. 27, 2009230, 95 4.San Luis Valley-Calumet-Comanche Transmission Project 750 - 14005/13Joint CPCN filing May 14, 2009 by PSCo and TSG&T 230, 95 345, 45 5.Missile Site 345kV Switching Station5/13Petition for Declaratory Ordern/a 6.Lamar/Vilas-Front Range 345/500kV Lamar-Comanche Lamar-Missile Site 800 - 100016–17Studies / CPCN 2010345, 330 7.Ault-Cherokee 230kV Transmission Project300 - 60015–16TBD230, 85 8.Pawnee-Daniels Park 345kV Transmission Project 300 - 50016–17TBD 230, 15 345, 95 2009 SB-100 Transmission Plan

5. 5 5 Lamar – Front Range Scope  Purpose: evaluate transmission alternatives to reliably alleviate existing constraints that inhibit potential resource development in southeast and east central Colorado from reaching electrical customer loads along the Front Range.  Accommodate resource development in ERZ #3 (GDA 6) and ERZ #2 (GDA 5, 7)  Interconnect Lamar/Vilas to Comanche & Missile Site  Two Primary Alternatives  Eastern Corridor  Central Corridor

6. 6 Lamar – Front Range Alternative 1 100-500 500- 1500 100-300 100-200

7. 7 Resource Injection Scenario Lamar/ Energy Center VilasBurlington Cheyenne /Kiowa WrayBig Sandy CLRTPG (A)14200000 CLRTPG (C)250001150100200 C Scaled1382063055110 HPX65015050150250 LFR (1) GDA 5 Burlington - MS 100-500 LFR (2) GDA 6-5 Lamar – Burl-MS LFR (3) GDA 6 Lamar - Comanche

8. 8 Lamar – Front Range Alternative 2

9. 9 9 Lamar – Front Range Scope - Studies  Benchmark  Segment Analysis  Potential Phasing  Voltage  345/500  Circuits  Single/Double  2020 Base Case  PSCo/Tri-State Lead

10. 10 Questions