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.

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Transmission Ownership Colorado

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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)

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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

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Senate Bill 100 Project Status

Item Project Generation (MW)

In Service Date*

Project Status

1. Missile Site 230kV Switching Station 250 Dec. 2010 Project being implemented

2. Midway-Waterton 345kV Transmission Project

June 2011 Project being implemented

3. Pawnee-Smoky Hill 345kV Transmission project

500 June 2013 CPCN approved by the CPUC on Feb. 27, 2009. Project being implemented

4. San Luis Valley-Calumet-Comanche 345kV Transmission Project

750 - 1400 May 2013 Joint CPCN filing May 14, 2009 by PSCO and TSG&T. Evidentiary hearing in process

5. Missile Site 345kV Switching Station May 2013 Filed a declaratory order that CPCN is not necessary on April 26, 2010.

6. Lamar-Front Range 345kV•Lamar-Comanche

•Lamar-Missile Site

800 - 1000 2016 - 2017 Potential owners are PSCO, TSG&T and Black Hills. Joint technical studies are proceeding.

7. Lamar-Vilas 230/345kV transmission 2016 - 2017 Same as item 6

8. Ault-Cherokee 230kV Transmission Project

300 - 600 2015 - 2016 TBD*

9. Pawnee-Daniels Park 345kV Transmission Project

300 - 500 2016 - 2017 TBD*

*Project status and dates subject to change

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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 -2nd 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 Plan10-22-2009

New Lamar –Vilas 345 kV ~ISD 2016-2017

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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

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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

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PSCo Public Website and Contact Information

SB-100 web site• http://www.sb100transmission.com

High Plains Express web site• http://www.highplainsexpress.com