1. Southwest Renewable Energy Transmission Conference May 21, 2010 This report contains transmission planning data that may be conceptual in nature and is subject to change. The transmission projects listed may change scope or not be constructed.

2. 2 Transmission Ownership Colorado

3. 3 PSCo System Statistics 2009 4153 Miles of Transmission 251 Substations Served 25 Generators Served 9 Wind Generators (1258 MW) 1 Solar Generator (8 MW PV) PSCo Operating Company Peak Load 6249 MW (Actual) (7/14/2009) PSCo Balancing Authority Peak Load 7457 MW (Actual) (7/14/2009) Historical Peak Operating Company Load 6927MW (7/212005) Historical Peak Balancing Authority Load 7766MW (7/212005)

4. 4 Senate Bill 07-100 Upon recommendations by the 2006 Transmission Task Force on Reliable Electricity Infrastructure, the 66th General Assembly passed Senate Bill 07-100 Under SB 07-100, PSCo must meet the following requirements: Designate “Energy Resource Zones (ERZ)” Develop plans for the construction or expansion of transmission facilities necessary to deliver electric power consistent with the timing of the development of beneficial energy resources located in or near such zones Consider how transmission can be provided to encourage local ownership of renewable energy facilities Submit proposed plans, designations, and applications for certificates of public convenience and necessity to the commission for simultaneous review

5. 5 Senate Bill 100 Project Status ItemProjectGeneration (MW) In Service Date* Project Status 1.Missile Site 230kV Switching Station250Dec. 2010Project being implemented 2.Midway-Waterton 345kV Transmission Project June 2011Project being implemented 3.Pawnee-Smoky Hill 345kV Transmission project 500June 2013CPCN approved by the CPUC on Feb. 27, 2009. Project being implemented 4.San Luis Valley-Calumet-Comanche 345kV Transmission Project 750 - 1400May 2013Joint CPCN filing May 14, 2009 by PSCO and TSG&T. Evidentiary hearing in process 5.Missile Site 345kV Switching StationMay 2013Filed a declaratory order that CPCN is not necessary on April 26, 2010. 6.Lamar-Front Range 345kV Lamar-Comanche Lamar-Missile Site 800 - 10002016 - 2017Potential owners are PSCO, TSG&T and Black Hills. Joint technical studies are proceeding. 7.Lamar-Vilas 230/345kV transmission2016 - 2017Same as item 6 8.Ault-Cherokee 230kV Transmission Project 300 - 6002015 - 2016TBD* 9.Pawnee-Daniels Park 345kV Transmission Project 300 - 5002016 - 2017TBD* *Project status and dates subject to change

6. 6 New Lamar-Comanche 345 kV & Lamar - Missile Site 345 kV ~ISD 2016-2017 New San Luis Valley- Calumet-Comanche 230 & 345 kV lines ~ ISD 2013 New Midway-Waterton 345 kV ISD 2011 New Pawnee-Daniels Park 345 kV -2 nd circuit ~ISD 2016-2017 New Missile Site 230 kV (ISD 2010) & 345 kV (ISD 2013) New Ault-Cherokee 230 kV ~ISD 2015-2016 New Pawnee-Smoky Hill 345 kV, ISD 2013 Current SB-100 Transmission Plan 10-22-2009 New Lamar –Vilas 345 kV ~ISD 2016-2017

7. 7 High Plains Express Initiative Two 1,280 mile, 500kV, AC lines through WY, CO, NM and AZ 3,500 – 4,000 MW of transmission capacity Connects Regional Projects 11 parties participating Under second phase feasibility studies

8. 8 Completion of HPX Initiative Increased local generation Inclusion of new renewable generation plants –Reduced carbon footprint in the local community Cost of energy favors export of local generation Inability to utilize all local generation Sell generation on the wholesale market to New Mexico and Arizona

9. 9 PSCo Public Website and Contact Information SB-100 web site http://www.sb100transmission.com High Plains Express web site http://www.highplainsexpress.com