This document provides forward-looking statements and discusses risk factors that could cause actual results to differ from projections. It includes references to adjusted operating earnings that exclude certain factors. The appendix includes a reconciliation of adjusted operating earnings to GAAP earnings. Exelon Corporation had 2007 operating earnings of $2.9 billion and EPS of $4.32, with assets of $46.8 billion and debt of $14.8 billion. It has a diverse portfolio of nuclear, fossil, hydro, and renewable generation assets across multiple regions.

1. Exelon Corporation
Phillip S. Barnett
SVP and CFO, PECO Energy
September 16, 2008

2. Forward-Looking Statements
This presentation includes forward-looking statements within the meaning of the Private
Securities Litigation Reform Act of 1995, that are subject to risks and uncertainties. The factors
that could cause actual results to differ materially from these forward-looking statements
include those discussed herein as well as those discussed in (1) Exelon’s 2007 Annual Report
on Form 10-K in (a) ITEM 1A. Risk Factors, (b) ITEM 7. Management’s Discussion and
Analysis of Financial Condition and Results of Operations and (c) ITEM 8. Financial
Statements and Supplementary Data: Note 19; (2) Exelon’s Second Quarter 2008 Quarterly
Report on Form 10-Q in (a) Part II, Other Information, ITEM 1A. Risk Factors and (b) Part I,
Financial Information, ITEM 1. Financial Statements: Note 12; and (3) other factors discussed
in filings with the Securities and Exchange Commission by Exelon Corporation, Exelon
Generation Company, LLC, Commonwealth Edison Company, and PECO Energy Company
(Companies). Readers are cautioned not to place undue reliance on these forward-looking
statements, which apply only as of the date of this presentation. None of the Companies
undertakes any obligation to publicly release any revision to its forward-looking statements to
reflect events or circumstances after the date of this presentation.
This presentation includes references to adjusted (non-GAAP) operating earnings that exclude
the impact of certain factors. We believe that these adjusted operating earnings are
representative of the underlying operational results of the Companies. Please refer to the
appendix to this presentation for a reconciliation of adjusted (non-GAAP) operating earnings to
GAAP earnings.
2

3. The Exelon Companies
‘07 Operating Earnings: $2.9B
‘07 EPS: $4.32
Assets (1) : $46.8B
Total Debt (1) : $14.8B
Credit Rating (2): BBB
Illinois Pennsylvania
Nuclear, Fossil, Hydro & Renewable Generation
Utility Utility
Power Marketing
’07 Earnings: $2,331M ’07 Earnings: $200M $507M
’07 EPS: $3.45 ’07 EPS: $0.30 $0.75
Total Debt (1): $3.6B Total Debt (1): $5.2B $3.5B
Credit Rating (2): BBB+ Credit Ratings (2): BBB+ A
Note: All ’07 income numbers represent adjusted (Non-GAAP) Operating Earnings and EPS. Refer to Appendix for reconciliation of adjusted (non-GAAP) operating EPS to
GAAP EPS.
(1) As of 6/30/08.
(2) Standard & Poor’s senior unsecured debt ratings for Exelon and Generation and senior secured debt ratings for ComEd and PECO as of 9/11/08.
3

4. Financial Performance
Adjusted (non-GAAP) Operating EPS Total Shareholder Return
10/20/00 – 9/11/08
at e
th R
Assumes dividend reinvestment
row Source: Bloomberg
al G $4.32
nnu
dA
oun
mp
Co EXC
%
~12 $3.22 186%
$3.10
$2.78
$2.61
$2.41
UTY
$2.24
76%
$1.93
S&P 500
3%
10/00
4/01
10/01
4/02
10/02
4/03
10/03
4/04
10/04
4/05
10/05
4/06
10/06
4/07
10/07
4/08
2000 2001 2002 2003 2004 2005 2006 2007
4

5. Multi-Regional, Diverse Company
Electricity Customers: 3.8M Electricity Customers: 1.6M
Gas Customers: 0.5M
Total Capacity
Owned: 24,808 MW
Contracted: 7,524 MW
Total: 32,332 MW
New England Capacity
Owned: 194 MW
Midwest Capacity
Owned: 11,388 MW
Contracted: 4,271 MW Mid-Atlantic Capacity
Total: 15,659 MW Owned: 11,004 MW
Contracted: 336 MW
Total: 11,340 MW
ERCOT/South Capacity
Owned: 2,222 MW
Contracted: 2,917 MW
Total: 5,139 MW Generating Plants
Nuclear
Hydro
Coal/Oil/Gas Base-load
Intermediate
Peaker
Note: Megawatts based on Generation’s ownership as of 12/31/07,
using annual mean ratings for nuclear units (excluding Salem) and
summer ratings for Salem and the fossil and hydro units.
5

6. Exelon Generation
Protect Value
• Continue to focus on operating excellence,
cost management, and market discipline
Value Proposition • Support competitive markets
• Large, low-cost, low-emissions, • Pursue nuclear & hydro plant license
exceptionally well-run nuclear fleet extension and strategic investment in
material condition
• Complementary and flexible fossil and
hydro fleet • Maintain industry-leading talent
• Levered to power market fundamentals
(commodity prices, power prices, and Grow Value
capacity values)
• Pursue nuclear plant uprates (~350MW by
• End of below-market contracts in 2014) and investigate potential for more
Pennsylvania beginning 2011
• Pursue nuclear Construction and
• Potential carbon restrictions Operating License in Texas
• Capture increased value of low-carbon
generation portfolio
Exelon Generation is the premier unregulated generation company – positioned to
Exelon Generation is the premier unregulated generation company – positioned to
capture market opportunities and manage risk
capture market opportunities and manage risk
6

7. World-Class Nuclear Operator
Range of Fleet 2-Yr Avg Capacity Factor (2003-2007)
Average Capacity Factor
100% 100
EXC 93.5%
90%
95
80%
90
70%
60%
85
Percent
50%
80
40%
30% 75
20%
70 Range 5-Year Average
10%
0% 65
Non-Fleet Operated (21)
PGN (5)
ETR (11)
NMC (6)
CEG (5)
SO (6)
TVA (5)
DUK (7)
D (7)
FPL (6)
FE (4)
EXC (17)
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
Exelon Industry Operator (# of Reactors)
Note: Exelon data prior to 2000 represent ComEd-only nuclear fleet.
Sources: Platt’s, Nuclear News, Nuclear Energy Institute and Energy Information Administration (Department of Energy).
7

8. Total Portfolio Characteristics
2008 Expected Total Sales (GWh) (1)
2008 Expected Total Supply (GWh) (1)
IL Auction
Nuclear 138,100 12%
Fossil & Hydro (2) 33,800
PECO Load
Forward & Spot Purchases 17,400 22%
Total 189,300
ComEd Swap
Actual Hedges
3%
& Open
Position
63%
The value of our portfolio resides in our nuclear fleet
(1) As published at Exelon’s 12/19/07 Investor Conference.
8
(2) Includes purchases related to long-term contracts.

9. Hedging Targets
Power Team employs commodity hedging
Financial Hedging Range (1)
strategies to optimize Exelon
Generation’s earnings: Prompt Year Second Year Third Year
Prompt Year Second Year Third Year
• Maintain length for opportunistic sales (2008) (2009) (2010)
(2008) (2009) (2010)
• Use cross commodity option strategies to
Target Ranges
enhance hedge activities
90% - 98% 70% - 90% 50% - 70%
• Time hedging around view of market
fundamentals
Current Position
• Supplement portfolio with load following Above the
Top
~96%
products range*
of range
• Use physical and financial fuel products to
* Due to ComEd financial swap
manage variability in fossil generation output
Flexibility in our targeted financial hedge ranges allows us to be opportunistic while
Flexibility in our targeted financial hedge ranges allows us to be opportunistic while
mitigating downside risk
mitigating downside risk
(1) Percent financially hedged is our estimate of the gross margin that is hedged at a 95% confidence level given the current assessment of market volatility. The
formula is the gross margin at the 5th percentile / expected gross margin.
9

10. Exelon Is Uniquely Positioned for
Sustainable Value Creation
2011
(1)
th
PS Grow
~40% E
2008
ComEd
d
mE
Co
ExGen
ExGen PE
CO
PECO
(1) As presented at Exelon’s 12/19/07 Investor Conference. Assumes Henry Hub Gas Price $8.00/mmBtu, Coal (NAPP 3.0) $49.75/ton, PJM W-Hub ATC Price $63.00/MWh, NI-Hub
ATC Price $50.00/MWh. No assumption for carbon has been made for 2011.
10

11. Balance Sheet Capacity
2008 - 2012 Potential Uses of
2008 - 2012 Cumulative Available Cash (Illustrative) (4)
Available Cash
S&P “BBB” Range for FFO/Debt Ratio: 20% to 30%
18
• Growth opportunities
Available Cash after Dividend ($ B) (1) (2)
16
• Future unfunded liabilities
(3)
O/Debt
2 0 % FF
14
• Buffer against potentially lower
12
commodity prices
arget)
(EXC T
10 )
(3
ebt
% FFO/D
25
• Share repurchases or other
8
value return options
6
(3)
/Debt
30% FFO
4
2
0
(-25%) Forward Gas Prices as of 7/31/07 (+25%)
Gas Price Sensitivity
Exelon expects to create substantial incremental balance sheet capacity over the next
five years, based on planning assumptions
(1) Available Cash after Dividend = Cash Flow from Operations - CapEx - Dividends +/- Net Financings. Cash Flow from Operations = Net cash flows provided by operating
activities less net cash flows used in investing activities other than capital expenditures. Net Financing (excluding Dividends) = Net cash flows used in financing activities
excluding dividends paid on common stock. Assumes annualized dividend of $2.00 /share in 2008, growing 5% annually; actual amounts may vary, subject to board approval.
(2) Available Cash after Dividend excludes any benefit from potential carbon impact.
(3) See “FFO Calculation and Ratios” definitions slide in Appendix. FFO / Debt includes: debt equivalents for purchased power agreements, unfunded pension and other
postretirement benefits obligations, capital adequacy for energy trading, and related imputed interest.
(4) As presented at Exelon’s 12/19/07 Investor Conference. Provided solely to illustrate possible future outcomes that are based on a number of different assumptions, all of which
11
are subject to uncertainties and should not be relied upon as a forecast of future results.

12. Executing on Value Return Plan
Recent Share Repurchases - $3.25 billion
• 2008 Repurchases
– $0.5 billion accelerated share repurchase in February 2008
– $1.5 billion share repurchase announced in September 2008
• 2007 Repurchases
– $1.25 billion accelerated share repurchase in September 2007
Dividends
• Annual base dividend rate reset at $2.00/share in December 2007
– Anticipated to grow modestly over time (1)
– Higher base dividend reflected higher expected long-term earnings
due to improved market fundamentals
(1) Future dividends are subject to declaration by the Board of Directors.
12

13. Exelon’s Strategic Direction
+
Protect Today’s Value Grow Long-Term Value
• Deliver superior operating • Drive the organization to the next
performance level of performance
• Advance competitive markets • Set the industry standard for low
carbon energy generation and
• Protect the value of our generation
delivery through reductions,
• Build healthy, self-sustaining
displacement and offsets
delivery companies
• Rigorously evaluate and pursue
new growth opportunities
13

14. Appendix
14

15. Market Price Snapshot
Rolling 12 months, as of August 29, 2008. Source: OTC quotes and electronic trading system. Quotes are daily.
12 150
Forward NYMEX Natural Gas Forward NYMEX Coal
11.5 140
11 130
10.5 120
2010
10 110
2010
$ / MMBtu
$/Ton
9.5 100
9 90
2011
2011
8.5 80
8 70
7.5 60
7 50
9/07 10/07 11/07 12/07 1/08 2/08 3/08 4/08 5/08 6/08 7/08 8/08 9/07 10/07 11/07 12/07 1/08 2/08 3/08 4/08 5/08 6/08 7/08 8/08
PJM-West and Ni-Hub On-Peak Forward Prices PJM-West and Ni-Hub Wrap Forward Prices
75
105 2010 PJM-West
2010 PJM-West 70
65
95
60
$ / MWhr
55
$/MWhr
85 2011 PJM-West
2011 PJM-West
50
2010 Ni-Hub
75
45
2011 Ni-Hub
40
65
35
2011 Ni-Hub
2010 Ni-Hub
55 30
15
9/07 10/07 11/07 12/07 1/08 2/08 3/08 4/08 5/08 6/08 7/08 8/08 9/07 10/07 11/07 12/07 1/08 2/08 3/08 4/08 5/08 6/08 7/08 8/08

16. Market Price Snapshot
Rolling 12 months, as of August 29, 2008. Source: OTC quotes and electronic trading system. Quotes are daily.
12.5 100
Houston Ship Channel Natural Gas ERCOT North On-Peak Forward Prices
Forward Prices
12
95
11.5
90
11
10.5
85
$ / MMBtu
2010
$ / MWhr
10
2010
80
9.5
9 75
8.5 2011 2011
70
8
7.5 65
9/07 10/07 11/07 12/07 1/08 2/08 3/08 4/08 5/08 6/08 7/08 8/08 9/07 10/07 11/07 12/07 1/08 2/08 3/08 4/08 5/08 6/08 7/08 8/08
ERCOT North On-Peak v. Houston Ship Channel ERCOT On Peak Spark Spread
18.5
10
Assumes a 7.2 Heat Rate, $1.50 O&M, and $.15 adder
Implied Heat Rate 17.5
9.8
16.5
9.6
15.5
9.4
14.5
MMBtu / MWhr
9.2
2010
$ / MWhr
13.5
2011
9
12.5
8.8
2010 11.5
8.6
10.5
8.4 9.5
2011
8.2 8.5
8 7.5
16
9/07 10/07 11/07 12/07 1/08 2/08 3/08 4/08 5/08 6/08 7/08 8/08 9/07 10/07 11/07 12/07 1/08 2/08 3/08 4/08 5/08 6/08 7/08 8/08

17. FFO Calculation and Ratios
FFO Calculation FFO Interest Coverage
Net Income
FFO + Adjusted Interest
Add back non-cash items:
Adjusted Interest
+ Depreciation, amortization (including nucl fuel amortization), AFUDC/Cap. Interest
Net Interest Expense (Before AFUDC & Cap. Interest)
+ Change in Deferred Taxes
- PECO Transition Bond Interest Expense
+ Gain on Sale, Extraordinary Items and Other Non-Cash Items (3)
+ 7% of Present Value (PV) of Operating Leases
- PECO Transition Bond Principal Paydown
+ Interest on imputed debt related to PV of Purchased Power Agreements
= FFO (PPA), unfunded Pension and Other Postretirement Benefits (OPEB)
obligations, and Capital Adequacy for Energy Trading (2), as applicable
= Adjusted Interest
Debt to Total Cap FFO Debt Coverage
Adjusted Book Debt Rating Agency Debt FFO
Total Adjusted Capitalization Rating Agency Capitalization Adjusted Debt (1)
Debt: Adjusted Book Debt Debt:
+ LTD + Off-balance sheet debt equivalents (2) + LTD
+ STD + ComEd Transition Bond Principal Balance + STD
- Transition Bond Principal Balance - PECO Transition Bond Principal Balance
= Adjusted Book Debt = Rating Agency Debt Add off-balance sheet debt equivalents:
+ A/R Financing
Capitalization: Total Adjusted Capitalization + PV of Operating Leases
+ Total Shareholders' Equity - Goodwill + 100% of PV of Purchased Power Agreements (2)
+ Preferred Securities of Subsidiaries + Off-balance sheet debt equivalents (2) + Unfunded Pension and OPEB obligations (2)
+ Capital Adequacy for Energy Trading (2)
+ Adjusted Book Debt
= Adjusted Debt
= Total Adjusted Capitalization = Total Rating Agency Capitalization
Note: Reflects S&P guidelines and company forecast. FFO and Debt related to non-recourse debt are excluded from the calculations.
(1) Uses current year-end adjusted debt balance.
(2) Metrics are calculated in presentation unadjusted and adjusted for debt equivalents and related interest for PPAs, unfunded Pension and OPEB obligations, and Capital
Adequacy for Energy Trading.
(3) Reflects depreciation adjustment for PPAs and decommissioning interest income and contributions.
17

18. GAAP EPS Reconciliation 2000-2002
2000 GAAP Reported EPS $1.44
Change in common shares (0.53)
Extraordinary items (0.04)
Cumulative effect of accounting change --
Unicom pre-merger results 0.79
Merger-related costs 0.34
Pro forma merger accounting adjustments (0.07)
2000 Adjusted (non-GAAP) Operating EPS $1.93
2001 GAAP Reported EPS $2.21
Cumulative effect of adopting SFAS No. 133 (0.02)
Employee severance costs 0.05
Litigation reserves 0.01
Net loss on investments 0.01
CTC prepayment (0.01)
Wholesale rate settlement (0.01)
Settlement of transition bond swap --
2001 Adjusted (non-GAAP) Operating EPS $2.24
2002 GAAP Reported EPS $2.22
Cumulative effect of adopting SFAS No. 141 and No. 142 0.35
Gain on sale of investment in AT&T Wireless (0.18)
Employee severance costs 0.02
2002 Adjusted (non-GAAP) Operating EPS $2.41
18

19. GAAP EPS Reconciliation 2003-2005
2003 GAAP Reported EPS $1.38
Boston Generating impairment 0.87
Charges associated with investment in Sithe Energies, Inc. 0.27
Employee severance costs 0.24
Cumulative effect of adopting SFAS No. 143 (0.17)
Property tax accrual reductions (0.07)
Enterprises’ Services goodwill impairment 0.03
Enterprises’ impairments due to anticipated sale 0.03
March 3 ComEd Settlement Agreement 0.03
2003 Adjusted (non-GAAP) Operating EPS $2.61
2004 GAAP Reported EPS $2.78
Charges associated with debt repurchases 0.12
Investments in synthetic fuel-producing facilities (0.10)
Employee severance costs 0.07
Cumulative effect of adopting FIN 46-R (0.05)
Settlement associated with the storage of spent nuclear fuel (0.04)
Boston Generating 2004 impact (0.03)
Charges associated with investment in Sithe Energies, Inc. 0.02
Charges related to the now terminated merger with PSEG 0.01
2004 Adjusted (non-GAAP) Operating EPS $2.78
2005 GAAP Reported EPS $1.36
Investments in synthetic fuel-producing facilities (0.10)
Charges related to the now terminated merger with PSEG 0.03
Impairment of ComEd’s goodwill 1.78
2005 financial impact of Generation’s investment in Sithe (0.03)
Cumulative effect of adopting FIN 47 0.06
2005 Adjusted (non-GAAP) Operating EPS $3.10
19

20. GAAP EPS Reconciliation 2006-2007
2006 GAAP Reported EPS $2.35
Mark-to-market adjustments from economic hedging activities (0.09)
Investments in synthetic fuel-producing facilities 0.04
Charges related to now terminated merger with PSEG 0.09
Severance charges 0.03
Nuclear decommissioning obligation reduction (0.13)
Recovery of debt costs at ComEd (0.08)
Impairment of ComEd’s goodwill 1.15
Recovery of severance costs at ComEd (0.14)
2006 Adjusted (non-GAAP) Operating EPS $3.22
2007 GAAP Earnings Per Share $4.05
Mark-to-market adjustments from economic hedging activities 0.15
2007 Illinois electric rate settlement 0.41
Investments in synthetic fuel-producing facilities (0.14)
Nuclear decommissioning obligation reduction (0.03)
Termination of State Line PPA (0.19)
Georgia Power tolling agreement 0.11
City of Chicago settlement 0.02
Non-cash deferred tax items (0.04)
Settlement of a tax matter at Generation related to Sithe (0.01)
Sale of Generation's investments in TEG and TEP (0.01)
2007 Adjusted (non-GAAP) Operating Earnings (Loss) Per Share $4.32
Note: Amounts may not add due to rounding.
20
(1) Amounts shown per Exelon share and represent contributions to Exelon's EPS.

21. Exelon Investor Relations Contacts
Inquiries concerning this presentation Investor Relations Contacts:
should be directed to:
Chaka Patterson, Vice President
Exelon Investor Relations
312-394-7234
10 South Dearborn Street
Chaka.Patterson@ExelonCorp.com
Chicago, Illinois 60603
312-394-2345
312-394-4082 (Fax) Karie Anderson, Director
312-394-4255
Karie.Anderson@ExelonCorp.com
For copies of other presentations,
annual/quarterly reports, or to be
Marybeth Flater, Manager
added to our email distribution list
please contact: 312-394-8354
Marybeth.Flater@ExelonCorp.com
Felicia McGowan, Executive Admin
Coordinator
312-394-4069
Felicia.McGowan@ExelonCorp.com
21