Public Service Company of Colorado (PSCo) presented its plans and financial results at an analyst meeting. PSCo's resource plan aims to reduce carbon emissions 10% by 2017 and 20% by 2020 through increasing renewable energy and demand-side management. The plan calls for adding 800 MW of wind, 225 MW of solar, and 360 MW of demand-side management by 2015. Environmental groups praised the plan for establishing precedent as the only Western utility to commit to significant carbon reductions. PSCo expects the plan will allow it to achieve environmental goals at a reasonable cost to customers.

1. Public Service Company
of Colorado Plans
Tim Taylor
President and CEO
Public Service Company of Colorado,
an Xcel Energy Company
New York Analyst Meeting
December 5, 2007

2. Safe Harbor
This material includes forward-looking statements that are subject to
certain risks, uncertainties and assumptions. Such forward-looking
statements include projected earnings, cash flows, capital
expenditures and other statements and are identified in this document
by the words “anticipate,” “estimate,” “expect,” “projected,”
“objective,” “outlook,” “possible,” “potential” and similar
expressions. Actual results may vary materially. Factors that could
cause actual results to differ materially include, but are not limited to:
general economic conditions, including the availability of credit,
actions of rating agencies and their impact on capital expenditures;
business conditions in the energy industry; competitive factors;
unusual weather; effects of geopolitical events, including war and acts
of terrorism; changes in federal or state legislation; regulation; actions
of accounting regulatory bodies; the higher degree of risk associated
with Xcel Energy’s nonregulated businesses compared with
Xcel Energy’s regulated business; and other risk factors listed from
time to time by Xcel Energy in reports filed with the SEC, including
Exhibit 99.01 to Xcel Energy’s report on Form 10-K for year 2006.

3. Public Service Company of Colorado
2006 Financials
Colorado Earnings Cont. Op $221 million
Assets $8,363 million
GAAP ROE 7.8%
Equity Ratio 56.5%
2006 Owned Generation
Coal 2,617 MW
Gas 855 MW
Renewable 242 MW
Wind 27 MW
2006 Customers
2006 Retail Sales
Electric 1,320,000 (Thousands of MWh / MMBtu)
Gas 1,260,000 Electric 27,198
Gas 125,123

4. 2006 Rate Base and ROE
Dollars in millions
Weather
Normalized
Rate Base Earned ROE
Colorado Electric $3,292 7.7%
Colorado Gas 1,106 7.8
Wholesale 418 Not Reported
Total Rate Base $4,816
Regulated Equity Ratio = 60.3%

5. Environmental Policy
Demand-Side
Renewable Management
Portfolio (annual GWh Carbon
State Standards savings) Reduction
Colorado 20% by 2020 * 0.35% N/A
* Renewable Bill Timeline Renewable Bill Provides:
Opportunity to own 25%
5% by 2008
of incremental wind
10% by 2011
50% if ownership creates
15% by 2015
economic development
20% by 2020 benefits

6. Current Position
Wind capacity 1,084 MW
Wind in WindSource Over 255 GWh
Photovoltaic solar energy 8 MW
Customer-sited photovoltaic
capacity in SolarRewards 9 MW
DSM electric sales reduction 0.7%
— Doubles DSM Commitment

7. Resource Planning Process
Last resource plan filed April 2004
Legislation modified process
Three resource portfolio scenarios modeled
and optimized
Costs and benefits of each scenario reviewed
for the 2008–2015 time period
Preferred resource plan selected and submitted
to the PUC on November 15, 2007
Commission approval in 7 months

8. Colorado Resource Plan
MW
Wind 800 2007 2015
1,884 MW
Central Solar 225 271 MW
Customer-sited 1,618 GWh
1,084 MW
Solar 29
147 GWh
DSM 360 17 MW
Gas Generation 980
Wind Solar DSM
Biomass 4
Energy Sources
Retirements 340

9. Colorado Resource Plan Impact
System Energy Mix System Energy Mix
2007 2015
Wind
Gas
15%
Gas
27%
Hydro 0.8%
16%
Wind 3%
Biomass 0.2%
Hydro 1%
Solar 2%
Econ 5%
Econ 4%
Coal Coal
64% 62%

10. Acquisition Plan
Acquire resources through 2015 by staged/targeted
acquisitions; defer 2016 and beyond to future plans
Build new natural gas-fired combined cycle at Arapahoe
Target 50% wind ownership through legislative set aside
— Acquire through Build-Transfer/PPA RFP
25 MW solar in 2011 through PPA RFP
Customer-sited solar projects through rebates and bids
Own future generic thermal and solar thermal through
Reverse Auction/Build Transfer

11. Recovery on Capital Expenditures
Dollars in millions
1,200
$945
1,000
$850
$750
800
$680
$650
600
400
200
0
2007 2008 2009 2010 2011
Traditional Enhanced Recovery Depreciation

12. Colorado Recovery Mechanisms
Ability to file either historic or forecast test year
Purchased capacity cost adjustment
Comanche 3 – forward CWIP via general rate case
Transmission rider
Renewable Energy rider
IGCC rider (if there is an approved project)
Demand-Side Management Cost Adjustment rider
Air Quality Improvement rider
Energy Cost adjustment
Gas Cost adjustment
Partial decoupling on retail natural gas

13. Key Priorities
Achieve favorable regulatory treatment
— Forecast test year
— Implement cost recovery riders
Achieve carbon reduction goals, while increasing
company-owned generation
— Demand-Side Management
— Colorado Resource Plan
— 10% reduction by 2017; 20% by 2020
Strengthen people and talent management
Strengthen transmission and distribution
infrastructure

14. Positioned for Success
High customer satisfaction
Competitive advantages through geography
— Wind
— Solar
Partnering with key stakeholders
Constructive regulatory recovery mechanisms
Resource plans deliver carbon reduction
— 10% reduction from 2005 levels by 2017
— 2009 plan to deliver 20% reduction by 2020
Able to achieve plan at reasonable cost to customers

15. Environmentalist Comments
“It is one of the most significant resource plans being submitted
by any utility anywhere in the country. It gets us on the path to
reducing carbon emissions. It provides a significant boost
to the new energy economy. And it will help protect ratepayers.”
Matt Baker - Director, Environment Colorado
“In the fine tradition of Colorado’s pioneers, Xcel Energy is
charting the innovative and cost-effective path forward to cut
global-warming pollution, protect human health and propel
Colorado’s clean energy economy.”
Vickie Patton – Deputy General Counsel, Environmental Defense
“It’s the only Western utility to put forth a plan to cut its carbon-
dioxide emissions. It’s precedent setting. It should be a model
for other utilities.”
John Nielsen – Energy Project Director, Western Resource Advocates