Constellation Energy
Q1 2007 Earnings Presentation
April 25, 2007

Forward-looking Statements Disclaimer
Certain statements made in this presentation are forward-looking statements and may contain words such as “believes,” “anticipates,” “expects,”
“intends,” “plans,” and other similar words. We also disclose non-historical information that represents management’s expectations, which are based
on numerous assumptions. These statements are not guarantees of future performance and are subject to risks and uncertainties that could cause
actual results to be materially different from projected results. These risks include, but are not limited to: the timing and extent of changes in
commodity prices for energy including coal, natural gas, oil, electricity, nuclear fuel, and emissions allowances; the timing and extent of deregulation
of, and competition in, the energy markets, and the rules and regulations adopted on a transitional basis in those markets; the conditions of the
capital markets, interest rates, availability of credit, liquidity and general economic conditions, as well as Constellation Energy’s and BGE’s ability to
maintain their current credit ratings; the ability to attract and retain customers in our competitive supply activities and to adequately forecast their
energy usage; the effectiveness of Constellation Energy’s and BGE’s risk management policies and procedures and the ability and willingness of our
counterparties to satisfy their financial and other commitments; the liquidity and competitiveness of wholesale markets for energy commodities;
uncertainties associated with estimating natural gas reserves, developing properties and extracting gas; operational factors affecting the operations of
our generating facilities (including nuclear facilities) and BGE’s transmission and distribution facilities, including catastrophic weather-related
damages, unscheduled outages or repairs, unanticipated changes in fuel costs or availability, unavailability of coal or gas transportation or electric
transmission services, workforce issues, terrorism, liabilities associated with catastrophic events, and other events beyond our control; the inability of
BGE to recover all its costs associated with providing customers service; the effect of weather and general economic and business conditions on
energy supply, demand, and prices; regulatory or legislative developments that affect deregulation, transmission or distribution rates, demand for
energy, or that would increase costs, including costs related to nuclear power plants, safety, or environmental compliance; the actual outcome of
uncertainties associated with assumptions and estimates using judgment when applying critical accounting policies and preparing financial
statements, including factors that are estimated in applying mark-to-market accounting, such as the ability to obtain market prices and in the absence
of verifiable market prices, the appropriateness of models and model impacts (including, but not limited to, extreme contractual load obligations,
unit availability, forward commodity prices, interest rates, correlation and volatility factors); changes in accounting principles or practices; losses on
the sale or write-down of assets due to impairment events or changes in management intent with regard to either holding or selling certain assets; our
ability to successfully identify and complete acquisitions and sales of businesses and assets; and cost and other effects of legal and administrative
proceedings that may not be covered by insurance, including environmental liabilities. Given these uncertainties, you should not place undue reliance
on these forward-looking statements. Please see our periodic reports filed with the SEC for more information on these factors. These forward-
looking statements represent estimates and assumptions only as of the date of this presentation, and no duty is undertaken to update them to reflect
new information, events or circumstances.
2

Use of Non-GAAP Financial Measures
Constellation Energy presents adjusted earnings per share (adjusted EPS) in addition to its reported earnings per share in accordance with
generally accepted accounting principles (reported GAAP EPS). Adjusted EPS is a non-GAAP financial measure that differs from reported
GAAP EPS because it excludes the cumulative effects of changes in accounting principles, discontinued operations, special items (which we
define as significant items that are not related to our ongoing, underlying business or which distort comparability of results) included in
operations, the impact of certain economic, non-qualifying hedges, and synfuel earnings. The mark-to-market impact of economic non-
qualifying hedges is significant to reported results, but economically neutral to the company in that offsetting gains or losses on underlying
accrual positions will be recognized in the future. Synfuel earnings are excluded due to the potential for oil price volatility to result in a difficult-
to-forecast phase-out of tax credits. We present adjusted EPS because we believe that it is appropriate for investors to consider results
excluding these items in addition to our results in accordance with GAAP. We believe this measure provides a picture of our results that is
comparable among periods since it excludes the impact of items such as workforce reduction costs or gains and losses on the sale of assets,
which may recur occasionally, but tend to be irregular as to timing, thereby distorting comparisons between periods. However, investors should
note that this non-GAAP measure involves judgment by management (in particular, judgment as to what is classified as a special item or an
economic, non-qualifying hedge to be excluded from adjusted earnings). This non-GAAP measure is also used to evaluate management's
performance and for compensation purposes. Constellation Energy also provides its earnings guidance in terms of adjusted EPS. Constellation
Energy is unable to reconcile its guidance to GAAP earnings per share because we do not predict the future impact of special items, economic,
non-qualifying hedges or synfuel earnings due to the difficulty of doing so. The impact of special items, economic, non-qualifying hedges, or
synfuel earnings could be material to our operating results computed in accordance with GAAP. We note that such information is not in
accordance with GAAP and should not be viewed as an alternative to GAAP information. A reconciliation of Non-GAAP information to
GAAP information is included either on the slide where the information appears or on one of the slides in the Non-GAAP Measures section
provided at the end of the presentation. Please see the Summary of Non-GAAP Measures included to find the appropriate GAAP
reconciliation and its related slide(s). These slides are only intended to be reviewed in conjunction with the oral presentation to which they
relate.
3

Q1 2007 Adjusted EPS Summary
Q1 2007 Q1 2006
($ per share)
GAAP Earnings $1.07 $0.63
Special Items 0.01 (0.06)
Loss on Economic Non-Qualifying Hedges 0.05 0.06
Synfuel Earnings (1) (0.10) (0.02)
Adjusted Earnings (2) $1.03 $0.61
Q1 Earnings Guidance (3) $0.80 - $1.00
(1) Represents synfuel earnings of $0.15 per share and expected synfuel phase-out risk of $0.05 per share in Q1’07
(2) Excludes special items, certain economic, non-qualifying hedges and synfuel earnings
(3) Excludes estimated synfuel earnings of $0.11 per share and estimated synfuel phase-out risk of $0.06 per share
See Appendix 4

Q1 2007 Operating Highlights
• Solid earnings growth driven by strong Merchant performance
• Completed first quarter nuclear refueling outages
• Announced agreement to acquire of select contracts from Progress Ventures
– Commodities Group to assume full requirement contracts with 16 electric membership
cooperatives in Georgia with a peak load of 3,100 MWs
– Expect to receive approximately $350 million cash from Progress Ventures upon closing
• Investing $310 million in retail and wholesale natural gas businesses
– Acquired working interests in two gas and oil producing properties in Oklahoma
– Announced agreement to acquire Cornerstone Energy
Similar C&I business model with a complementary geographic footprint
Expected increase in NewEnergy gas volume to over 500 bcf (~7% market share)
Neutral to 2007 earnings; accretive in 2008 and beyond
Expected to close in May 2007
5

Constellation’s Natural Gas Strategy
• Focused upstream natural gas strategy
Upstream Investment Strategy
– Selectively invest in gas producing assets
with established partners
– Develop properties and hedge production
to lock in returns
– Monetize mature investments through
Strategic Portfolio
drop-down sales to Constellation Energy
Investment Development
Partners (CEP) or third parties
• Scale of natural gas business
– Net invested capital of approximately
$550 million
– Working interest in 10 properties
– Proved reserves of about 260 bcfe (1) Harvest
– Projected 2007 production volume of
18.1 bcfe (1)
6
(1) Pro forma for Q1 2007 acquisitions; Constellation Energy estimates; excludes Constellation Energy Partners reserves and production volumes

Maryland Update
• Maryland Public Service Commission
– New chairman and commissioners appointed and seated in first quarter
– Opt-in Rate Transition Plan filing progressing through PSC process
– Maryland PSC approved pilot programs for Demand Response (DRI) and Advanced
Metering (AMI)
• 2007 Maryland Legislative Session resulted in extension of time for Maryland PSC to
complete industry studies ordered in last year’s special legislative session
– PSC to submit an interim report by December 1, 2007
– PSC to submit a final report by December 1, 2008
7

Strategic Outlook
• Capacity market reform
– Recent auction results suggest capacity market reform is working as intended
• Potential expansion of Mid-Atlantic Fleet
– Filed a Feasibility Study with PJM for a potential new gas-fired peaking plant at one of
Constellation’s existing facilities
– Continuing to develop option for potential new nuclear plant at Calvert Cliffs
• Maryland officially joined the Regional Greenhouse Gas Initiative (RGGI)
• Constellation is well-positioned for carbon constrained environment
– Low-emitting fleet with approximately 60% of megawatt hours coming from zero-emitting
sources--nuclear and hydro
– Our commodities trading experience, position, extensive market knowledge and solid risk
management capabilities will be highly leveragable in an emissions trading marketplace
– Constellation NewEnergy is currently one of the largest suppliers of “green” products to
retail customers
– New nuclear initiative could provide future growth opportunities
8

Earnings Outlook
$6.50
+10%
$6.00
5.25 - 5.75
Adjusted EPS (1)
$5.50
$5.00
4.30 - 4.65
$4.50
$4.00
3.61
$3.50
$3.00
2006 2007E 2008E 2009E
• Reaffirming earnings guidance for 2007 and 2008
• 2009 adjusted EPS growth of approximately 10% over 2008
(1)Adjusted for the effect of special items, certain economic, non-qualifying hedges, and synfuel earnings
9
See Appendix

Poised to Succeed in 2007 and Beyond
• Clear and substantial earnings growth that is highly hedged
– Projecting 21% to 26% compound annual earnings growth from 2006 through 2008
– Forecasting 2009 earnings growth of 10% over 2008 earnings
• Constellation has delivered superior results over the past five years
– Predictably and consistently delivered on earnings guidance through a variety of market
conditions
– Improved ROIC to 9% in 2006 from below 7% in 2001; forecasted to be 11% in 2008
– Realized annual total shareholder return of 33% per annum since management team
came together in late 2001
• Constellation is well-positioned to take advantage of opportunities presented by the
market
– High-quality assets in high-value markets
– Market-leading position in power and strong presence in gas and coal markets
– Industry-leading risk management capabilities and disciplined investment approach
– Strong balance sheet
10

Financial Overview
E. Follin Smith
Executive Vice President, Chief Financial
Officer and Chief Administrative Officer

Financial Highlights
• Solid Merchant earnings performance
– Mid-Atlantic Fleet returning to profitability as below-market hedges roll off
– NewEnergy experienced lower costs to serve load and higher as-priced margins
– Wholesale Competitive Supply executed in line with plan
• Progress on capital plan
– Announced $310 million of investment in upstream gas properties and
acquisition of Cornerstone Energy
– Upon closing, expect to receive cash payment of about $350 million from
Progress Ventures
– Repaid maturing debt of $120 million in Q1 2007 and $600 million in April 2007
• Continued productivity improvements
– Delivered $8 million of productivity savings in Q1 2007
– On track to achieve 2007 productivity target of $60 to $65 million
12

Q1 2007 Earnings Summary
($ per share) Q1 2007 Q1 2006
GAAP Earnings $1.07 $0.63
Special Items 0.01 (0.06)
Loss on Economic Non-Qualifying Hedges 0.05 0.06
Synfuel Earnings (1) (0.10) (0.02)
Adjusted Earnings (2) $1.03 $0.61
Q1 Earnings Guidance (3) $0.80 - $1.00
Adjusted Earnings Change
($ per share) Q1 2007 Q1 2006 EPS %
Merchant $0.62 $0.22 $0.40 182%
Utility 0.36 0.38 (0.02) (5%)
Other Non-regulated 0.05 0.01 0.04 N.M.
Adjusted Earnings (2) $1.03 $0.61 $0.42 69%
(1) Represents synfuel earnings of $0.15 per share and expected synfuel phase-out risk of $0.05 per share in Q1’07
(2) Excludes special items, certain economic., non-qualifying hedges and synfuel earnings
(3) Excludes estimated synfuel earnings of $0.11 per share and estimated synfuel phase-out risk of $0.06 per share
13
See Appendix

BGE
Adjusted Earnings vs. Guidance
Q1 2007
($ per share)
Actual Guidance
Adjusted Earnings $0.36 $0.30 - $0.35
Adjusted Earnings vs. Prior Year
($ per share)
Q1 2007 Q1 2006 Change
Adjusted Earnings $0.36 $0.38 ($0.02)
See Appendix
14

Merchant
Adjusted Earnings vs. Guidance
Q1 2007
($ per share)
Actual (1) Guidance
Adjusted Earnings $0.62 $0.42 - $0.62
Adjusted Earnings vs. Prior Year
Q1 2007 Q1 2006 Change
($ per share)
Adjusted Earnings (1) $0.62 $0.22 $0.40
Variance Primarily Due to:
+63¢ Mid-Atlantic Fleet Price -26¢ Wholesale Competitive Supply New Business
+9¢ NewEnergy -6¢ Wholesale Competitive Supply Backlog
+8¢ Lower Net Interest Expense -7¢ Loss of CTC Revenue
(1) Excludes special items, certain economic, non-qualifying hedges and synfuel earnings
See Appendix
15

Wholesale Competitive Supply (1)
Change
($ in millions)
Q1 2007 Q1 2006 $ %
Total Already Originated
Business (2) $69 $88 ($19) (21%)
New Business
Originated & Realized (2) 24 17 7
Portfolio Management & Trading 29 98 (69)
Total New Business Realized (2) 53 115 (62) (54%)
Total Contribution Margin (2) $122 $203 ($81) (40%)
(1) Excludes special items, certain economic, non-qualifying hedges and synfuel results
(2) Includes power, gas (non-project), and coal gross margin and gas project margin (project revenue less operating, depreciation, depletion and interest expenses incurred at
the project level). Including gas project-level expenses of $17 million in Q1 2007 and $12 million in Q1 2006, total wholesale competitive supply gross margin in Q1 2007
and Q1 2006 was $139 million and $215 million, respectively.
See Appendix
16

Wholesale Competitive Supply: Origination
Total Wholesale Competitive Supply Origination Value to be Realized (1)
Q1 2007 Q1 2006
($ in millions)
To Be Realized In:
Current Year $109 $227
Future Years 381 171
Total Originated $490 $398
Current Year Target $469 $536 (2)
% of Current Year Target Achieved 23% 42%
Total Origination Target (including future years) $1,026 $908 (2)
% of Total Origination Target Achieved 48% 44%
(1) Includes power, gas (non-project), and coal gross margin and gas project margin (project revenue less operating, depreciation, depletion and interest expenses incurred
at the project level)
(2) Revised target
17

Wholesale Competitive Supply: Backlog
Backlog (1)
$600
(as of 3/31/07)
(2)
New Business Since 12/31/06
(3)
Value as of 12/31/06
109
$400
$ in millions
80 90
$200
369
189 170
$0
2007 2008 2009
(1) Includes power, gas (non-project), and coal gross margin and gas project margin (project revenue less operating, depreciation, depletion and interest expenses
incurred at the project level)
(2) Includes portfolio value changes for downstream gas and coal
18
(3) Reflects portfolio pricing on 12/31/06

NewEnergy
Electric
• Delivered 17.3 million MWhs in Q1 2007
• Realized gross margin/MWh of $4.66
– Lower costs to serve load
– Higher as-priced margins
• Retention Rates were lower in Q1 2007 following an acceleration of renewals in
Q4 2006
Gas
• Delivered about 100 billion cubic feet in Q1 2007
• Cornerstone acquisition expected to add 100 billion cubic feet (annually)
19

NewEnergy: Retail MWh Backlog
Contracted Retail MWh
(as of 3/31/07)
120
96
100
MWhs in millions
83
80 68
60
40 46
20 31
17
0
2006 2007 2008
Delivered Backlog Plan
• More than 75% of 2007 plan MWhs are delivered or contracted
20

Q1 2007 Cash Flow
Other
Merchant Utility Non-Reg Total
($ in millions)
Net Income $121 $67 $8 $196
Depreciation & Amortization 112 64 2 178
Capital Expenditures & Investments (404) (87) (1) (492)
Net CapEx (292) (23) 1 (314)
Working Capital & Other 198 100 17 315
Pension Adjustment (pre-tax) (105)
“Operating” Cash Flow 27 144 26 92
Asset Dispositions/Contract Restructuring (9) - - (9)
SB1 Rate Deferrals - (196) - (196)
Free Cash Flow $18 $(52) $26 (113)
Equity (Repurchase)/Issuance - Benefit Plans (55)
Dividends (68)
Net Cash Flow before Debt Issuances/(Payments) $(236)
21
See Appendix

Impact of Capacity Market Reform
• PJM capacity auction results for 2007/2008 planning year
– Eastern MAAC - $197.67
– Southwestern MAAC - $188.54
– Rest of Pool - $40.80
• Limited impact on Constellation earnings due to highly hedged capacity
position
(Position as of 3/31/07) 2008 2009
Percentage of capacity hedged (PJM & NY) 88% 52%
Note: Capacity position includes owned and purchased capacity less sold capacity
• Auctions for 2008/2009 plan year and 2009/2010 plan year are
scheduled for July 2007 and October 2007, respectively
22

Q2 2007 Guidance
Guidance Actual
Q2 2007 Q2 2006
($ per share)
Merchant $0.50 - $0.70 $0.32
BGE 0.04 - 0.08 0.11
Other Non-Regulated 0.00 - 0.02 0.02
Adjusted Earnings Per Share (1) $0.55 - $0.75 $0.45
• Improved generation performance due to Mid-Atlantic Fleet’s return to profitability as below-market
hedges roll off and better Calvert Cliffs outage performance
• Competitive supply approximately flat as lower wholesale portfolio management and trading is offset by
higher wholesale backlog and higher NewEnergy volumes and margins
• Lower interest expense
• Lower BGE results due to the loss of decommissioning income and higher costs
(1)Excludes special items, certain economic, non-qualifying hedges, and synfuel earnings
23
See Appendix

Additional Modeling Information

Merchant – Income Statement (1)
Change
($ in millions) Q1 2007 Q1 2006 $ %
$139 $215 ($76) (35%)
Wholesale Competitive Supply
122 75 47 62%
NewEnergy
284 112 173 155%
Mid-Atlantic Fleet
132 131 1 1%
Plants with PPAs
18 17 1 8%
Qualifying Facilities / Other
Gross Margin $696 $550 $146 27%
O&M (403) (346) (57) 16%
D&A (61) (62) 1 (2%)
Other Revenue and Expenses (36) (37) 1 (2%)
Total Costs below Gross Margin (500) (444) (55) 12%
EBIT $196 $105 $91 86%
Net Interest Expense (14) (38) 24 (64%)
Pre-Tax Income $182 $67 $115 170%
Income Tax (70) (27) (43) 162%
Net Income $112 $40 $72 176%
(1) Earnings excluding special items, certain economic, non-qualifying hedges, and synfuel earnings
See Appendix
25

Significant Excess Liquidity
Historical Excess Liquidity
8.0
7.0
Excess Liquidity
6.0
($ in billions)
5.0
4.0
3.0
2.0
1.0
- )
(1
2
3
4
5
6
02
01
03
04
05
06
02
3
04
5
6
2
3
4
5
6
7
-0
-0
-0
-0
-0
-0
-0
-0
-0
-0
-0
-0
-0
-0
c-
c-
c-
c-
c-
c-
p-
p-
n
n
n
n
n
p
p
p
r
r
r
r
r
r
De
De
De
De
De
De
Ju
Ju
Ju
Ju
Ju
Ma
Ma
Ma
Ma
Ma
Ma
Se
Se
Se
Se
Se
Cash & Bank Lines Bank Line Usage
• Significant liquidity to support business growth
• Sufficient liquidity to meet all stressed price and credit scenarios
26
(1) Excludes $2.5 billion bridge facility

Driving Additional Profits from Productivity
170 - 180
157 - 162
200
Pre-Tax Earnings ($ in millions)
150 97
100 50
50
0
(50) (40)
(100)
2004 2005 2006 2007E 2008E
Realized Target
• Year-to-date, realized $8 million, or 12% of our 2007 productivity target
• Since announcing our long-term productivity initiatives, we have added $105 million pre-tax
to ongoing annual profits
27

Balance Sheet / Credit Metrics
($ in billions) YE 2001 YE 2005 YE 2006 Q1 2007
Debt
Total Debt $5.2 $4.7 $5.0 $4.8
Less: Cash (0.1) (0.8) (2.3) (1.9)
Net Debt $5.1 $3.9 $2.7 $2.9
Capital
50% Trust Preferred 0.1 0.1 0.1 0.1
Equity (1) 4.1 5.1 4.9 5.7
Total Capital $9.4 $9.1 $7.7 $8.7
AOCI Balance - 0.3 1.4 0.7
3rd Party Cash Collateral - 0.4 0.3 0.3
Net Debt to Total Capital 55% 43% 35% 34%
Adjusted Net Debt to Adjusted Total Capital(2) 55% 44% 32% 33%
FFO / Debt 19% 29% 16% 22%
(1) Includes preferred stock and minority interest
(2) Excludes AOCI balance related to cash flow hedges of commodity transactions and 3rd Party Cash Collateral
See Appendix
28

Collateral Positions
Change vs.
Year-End
($ in millions) 12/31/05 12/31/06 3/31/07 B / (W)
Cash Collateral Held ($401) ($250) ($273) $23
Collateral Posted
Exchanges 285 701 398 303
3rd Parties 86 176 171 5
Subtotal Posted 371 877 569 308
Net Cash Posted Subtotal (30) 627 296 331
Letters of Credit Posted $2,486 $1,653 $1,549 104
Change in Total Collateral Posted $435
• The change in net collateral posted was favorable by $435 million at quarter-end versus
year-end as there was over a $300 million decrease in funds posted with exchanges
29

Limiting Variability – Portfolio Management
2008 2009
Percent Hedged as of 3/31/07
Power 92% 81%
Fuel 87% 65%
Sensitivity to Price Changes as of 3/31/07 ($ per share)
Power down $1/MWh, Fuel unchanged ($0.02) ($0.04)
Fuel down $0.10/MMBtu, Power unchanged 0.05 . 0.04
Power down $1/MWh, Fuel down $0.10/MMBtu $0.03 $0.00
• Accrual portfolio managed to reduce exposure of future earnings to commodity price changes
• MTM portfolio VaR levels remain low at average of $9.8 million in Q1 07
(1)
Numbers may not sum due to rounding
30
Note: Percent hedged includes Mid-Atlantic Fleet, Plants with PPA’s, Power Wholesale Competitive Supply and NewEnergy; excludes gas, coal and freight businesses

Synfuel Update (1)
2006 Actual Q1 2007 Actual 2007 Estimate
($ in millions, except per share amounts)
Pre-phase-out:
Pre-tax loss on production ($90) ($35) ($119)
Tax benefit of pre-tax loss 34 13 45
Tax credits before phase-out 120 40 153
Net income pre-phase-out $64 $17 $79
Impact of phase-out
Tax credit phase-out percentage 38% 29% 29%
Production expenses, net of tax $10 $5 $10
Current period credit phase-out (44) (12) (48)
2006 Tax credit true-up - 8 8
Net income impact of phase-out ($34) $1 ($26)
$30 $19 $53
Net synfuels income
Net synfuel EPS $0.16 $0.10 $0.30
The 2007 phase-out estimate is based on oil forwards and volatilities as of March 31, 2007
(1) Numbers may not sum due to rounding 31

South Carolina Synfuel (1)
2006 Actual Q1 2007 Actual 2007 Estimate
($ in millions, except per share amounts)
Pre-phase-out:
Pre-tax loss on production ($59) ($23) ($83)
Tax benefit of pre-tax loss 23 9 32
Tax credits before phase-out 76 27 104
Net income pre-phase-out $40 $13 $53
Impact of phase-out
Tax credit phase-out percentage 38% 29% 29%
Production expenses, net of tax $3 $2 $4
Current period credit phase-out (27) (8) (30)
2006 Tax credit true-up - 6 6
Net income impact of phase-out ($24) $- ($21)
$16 $13 $33
Net synfuels income
Net synfuel EPS $0.09 $0.07 $0.18
Production (tons in millions) 2.7 0.8 3.4
(1) Numbers may not sum due to rounding 32

Pace Synfuel (1)
2006 Actual Q1 2007 Actual 2007 Estimate
($ in millions, except per share amounts)
Pre-phase-out:
Pre-tax loss on production ($32) ($12) ($36)
Tax benefit of pre-tax loss 11 4 13
Tax credits before phase-out 44 13 49
Net income pre-phase-out $24 $5 $26
Impact of phase-out
Tax credit phase-out percentage 38% 29% 29%
Production expenses, net of tax $7 $3 $6
Current period credit phase-out (16) (4) (14)
2006 Tax credit true-up - 2 2
Net income impact of phase-out ($10) $1 ($6)
$14 $6 $20
Net synfuels income
Net synfuel EPS $0.07 $0.03 $0.11
Production (tons in millions) 1.4 0.4 1.7
(1) Numbers may not sum due to rounding 33

NewEnergy Performance
Electric
Electric Retention Rates
100%
Realized Electric Gross Margin (GM / MWh)
$7.00
75%
$5.00
50%
25% $3.00
0%
$1.00
1Q06 2Q06 3Q06 4Q06 1Q07
1Q05 2Q05 3Q05 4Q05 1Q06 2Q06 3Q06 4Q06 1Q07
Including Return to Utility Excluding Return to Utility
Gas
Realized Gas Gross Margin (GM / Dth)
Gas Retention Rates
100%
$0.30
$0.20
90%
$0.10
80% $0.00
1Q06 2Q06 3Q06 4Q06 1Q07 1Q05 2Q05 3Q05 4Q05 1Q06 2Q06 3Q06 4Q06 1Q07
34

NewEnergy Gross Margin Reconciliation
Q1 2007 Q1 2006
Total
Gross Margin $118 $73
Gross Margin (Excluding Non-Qualifying Hedges) 122 75
Adjusted Gross Margin 108 71
Electric
Gross Margin $96 $55
Gross Receipts Tax 9 10
Other Margin 6 (7)
Adjusted Electric Gross Margin $81 $52
% of Gross Receipts Tax / Gross Margin 9% 18%
Volume 17.3 15.3
Electric Margin / MWh $4.66 $3.39
Gas
Gross Margin $22 $18
Non-Qualifying Hedges (4) (2)
Other Margin (1) 1
Adjusted Gas Gross Margin $27 $19
Volume (Dth) 101.3 91.2
Gas Gross Margin / Dth $0.27 $0.21
35

Non-GAAP Reconciliations

Summary of Non-GAAP Measures
Slide(s) Where Used Slide Containing
Non-GAAP Measure in Presentation Most Comparable GAAP Measure Reconciliation
Adjusted EPS Reported GAAP EPS
Q107 Actual 4, 13, 14, 15 38
Q106 Actual 4, 13, 14, 15 38
EPS Guidance 4, 9, 13, 14, 15, 23 38
2006 Actual 9 39
Q206 Actual 23 39
Q107 Merchant Gross Margin 16, 25 Income from Operations / Net Income 40
Q106 Merchant Gross Margin 16, 25 41
Q107 Merchant Below Gross Margin 25 40
Q106 Merchant Below Gross Margin 25 41
Net Cash Flow before Debt Issuances/(Payments) 21 Operating, Investing and Financing Cash Flow 42
Free Cash Flow 21 42
Debt to Total Capital 28 Debt Divided by Total Capitalization 43
Projected Debt to Total Capital 28 43
37

Adjusted EPS Q1 2007 and 2006
We exclude special items and certain economic, non-qualifying fuel adjustment clause and gas transportation and storage hedges because we believe that it
is appropriate for investors to consider results excluding these items, in addition to our results in accordance with GAAP. We have also adjusted earnings to
exclude synfuel results due to the potential volatility and phase-out of the tax credits. We believe such a measure provides a picture of our results that is
comparable among periods since it excludes the impact of items, which may recur occasionally, but tend to be irregular as to timing and magnitude, thereby
distorting comparisons between periods. However, investors should note that this non-GAAP measure involves judgment by management (in particular,
judgment as to what is or is not classified as a special item). We also use this measure to evaluate performance and for compensation purposes.
RECONCILIATION:
Merchant Regulated Regulated Other
Energy Electric Gas BGE Nonreg. Total
A B C D = (B+C) E F =(A+D+E)
1Q07 ACTUAL RESULTS:
Reported GAAP EPS $ 0.66 $ 0.18 $ 0.18 $ 0.36 $ 0.05 $ 1.07
Loss from Discontinued Operations (0.01) - - - - (0.01) GAAP MEASURES
EPS Before Discontinued Operations 0.67 0.18 0.18 0.36 0.05 1.08
Special Items, Non-qualifying Hedges, and Synfuel Results Included in Operations:
Non-qualifying hedges (0.05) - - - - (0.05)
Synthetic fuel facility results 0.10 - - - - 0.10
Total Special Items, Non-qualifying Hedges, and Synfuel Results 0.05 - - - - 0.05
Adjusted EPS $ 0.62 $ 0.18 $ 0.18 $ 0.36 $ 0.05 $ 1.03 NON-GAAP MEASURE
1Q06 ACTUAL RESULTS:
Reported GAAP EPS $ 0.24 $ 0.19 $ 0.19 $ 0.38 $ 0.01 $ 0.63
Income from Discontinued Operations 0.07 - - - - 0.07 GAAP MEASURES
EPS Before Discontinued Operations 0.17 0.19 0.19 0.38 0.01 0.56
Special Items and Non-qualifying Hedges Included in Operations:
Non-qualifying Hedges (0.06) - - - - (0.06)
Merger-related Costs (0.01) - - - - (0.01)
Synthetic fuel facility results 0.02 - - - - 0.02
Total Special Items, Non-qualifying Hedges, and Synfuel Results (0.05) - - - - (0.05)
Adjusted EPS $ 0.22 $ 0.19 $ 0.19 $ 0.38 $ 0.01 $ 0.61 NON-GAAP MEASURE
EARNINGS GUIDANCE
Constellation Energy is unable to reconcile its earnings guidance excluding special items, non-qualifying hedges, and synfuel results to GAAP
earnings per share because we do not predict the future impact of special items such as the cumulative effect of changes in accounting
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principles, the disposition of assets, economic, nonqualifying hedges or synfuel results.

Adjusted EPS – 2Q06 and 2006
We exclude special items and certain economic, non-qualifying fuel adjustment clause and gas transportation and storage hedges because we believe that it
is appropriate for investors to consider results excluding these items, in addition to our results in accordance with GAAP. We have also adjusted earnings to
exclude synfuel results due to the potential volatility and phase-out of the tax credits. We believe such a measure provides a picture of our results that is
comparable among periods since it excludes the impact of items, which may recur occasionally, but tend to be irregular as to timing and magnitude, thereby
distorting comparisons between periods. However, investors should note that this non-GAAP measure involves judgment by management (in particular,
judgment as to what is or is not classified as a special item). We also use this measure to evaluate performance and for compensation purposes.
RECONCILIATION:
Merchant Regulated Regulated Other
Energy Electric Gas BGE Nonreg. Total
A B C D = (B+C) E F =(A+D+E)
2Q06 ACTUAL RESULTS:
Reported GAAP EPS $ 0.40 $ 0.11 $ (0.01) $ 0.10 $ 0.02 $ 0.52
Income from Discontinued Operations 0.11 - - - - 0.11 GAAP MEASURES
EPS Before Discontinued Operations 0.29 0.11 (0.01) 0.10 0.02 0.41
Special Items, Non-qualifying Hedges, and Synfuel Results Included in Operations:
Synthetic fuel facility results (0.01) - - - - (0.01)
Merger related transaction costs (0.02) (0.01) - (0.01) - (0.03)
Non-qualifying hedges - - - - - -
Total Special Items, Non-qualifying Hedges, and Synfuel Results (0.03) (0.01) - (0.01) - (0.04)
Adjusted EPS $ 0.32 $ 0.12 $ (0.01) $ 0.11 $ 0.02 $ 0.45 NON-GAAP MEASURE
2006 ACTUAL RESULTS:
Reported GAAP EPS $ 4.23 $ 0.66 $ 0.20 $ 0.86 $ 0.07 $ 5.16
Income from Discontinued Operations 1.03 - - - 0.01 1.04 GAAP MEASURES
EPS Before Discontinued Operations 3.20 0.66 0.20 0.86 0.06 4.12
Special Items, Non-qualifying Hedges, and Synfuel Results Included in Operations:
Gain on sale of gas-fired plants (excluding High Desert) 0.26 - - - - 0.26
Non-qualifying hedges 0.21 - - - - 0.21
Synthetic fuel facility results 0.16 - - - - 0.16
Workforce reduction costs (0.09) - - - - (0.09)
Merger-related costs (0.02) (0.01) - (0.01) - (0.03)
Total Special Items, Non-qualifying Hedges, and Synfuel Results 0.52 (0.01) - (0.01) - 0.51
Adjusted EPS $ 2.68 $ 0.67 $ 0.20 $ 0.87 $ 0.06 $ 3.61 NON-GAAP MEASURE
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1Q07 Merchant Gross Margin and Below Gross Margin
We utilize the non-GAAP financial measure of Gross Margin to highlight the relationship between the costs of and prices for energy in our Merchant Energy
business categories (i.e., Mid-Atlantic Fleet, Plants with PPAs, Wholesale Competitive Supply, NewEnergy, and QFs/Other). We believe this non-GAAP measure
helps investors to better understand the changes in the level of our Merchant Energy operating results for these categories from period to period.
RECONCILIATION: Quarter Ended March 31, 2007
GAAP Adjustments Merchant
GAAP Fuel & Purchased In Arriving Gross Margin
Merchant Revenue & Expense Categories Revenues Energy Expenses Difference At Gross Margin Notes (Non-GAAP)
($ millions)
Mid-Atlantic Fleet $ 547.9 $ 295.3 $ 252.6 $ 31 a, b, c $ 284
Plants with PPAs 151.2 18.0 133.2 (1) a 132
Wholesale Competitive Supply 1,445.2 1,292.0 153.2 (14) a , d, e 139 **
NewEnergy 2,221.5 2,103.5 118.0 4 d 122
QFs / Other 20.6 - 20.6 (2) e, f 18
Total Merchant $ 4,386.4 $ 3,708.8 $ 677.6 $ 18 $ 695
Adjustments Merchant Below
Arriving At Merchant Gross Margin
Total Merchant: GAAP Below Gross Margin (Non-GAAP)
Revenues less fuel and purchased energy expenses $ 677.6 $ 695
Operations and maintenance expenses (420.2) 17 g, h, i (403)
Depreciation, depletion, and amortization (62.9) 1 h, i (61)
Taxes other than income taxes (26.8) 26 k -
Accretion of asset retirement obligations (17.7) 18 k -
Income From Operations 150.0 231
Other income / (expense) 11.1 (46) b, k, l (36)
EBIT N/A 195
Fixed charges (20.5) 8 i, l (14)
Income Before Income Taxes 140.6 181
Income tax expense (19.0) (51) i, m (69)
Income from Continuing Operations 121.6 112
Loss from discontinued operations (1.6) 2j -
Net Income $ 120.0 $ 112
Details of Adjustments Made in Arriving at Merchant Gross Margin:
a Adjustment to remove $34 million loss from Mid-Atlantic Fleet and ($1 million) gain from Plants with PPA's of estimated gross margin created through active portfolio
management more appropriately categorized as a competitive supply activity.
b Adjustment to remove ($5 million) of decommissioning revenues from non-GAAP gross margin measure and included in Other Income. The offsetting decommissioning
expense was recorded in accretion of asset retirement obligations.
c Adjustment to remove $2 million of other indirect costs from non-GAAP gross margin as they are more appropriately categorized as operating expenses.
d Adjustment to remove $11 million loss in Wholesale Competitive Supply and $4 million loss in NewEnergy related to economic, non-qualifying hedges of
gas transport and storage contracts.
e Adjustment to remove synfuel losses from Wholesale Competitive Supply gross margin of $8 million and Other gross margin of $8 million.
f Adjustment to reflect ($10 million) of direct costs in Other for purposes of non-GAAP gross margin measure.
Details of Adjustments Made in Arriving at Merchant Below Gross Margin:
g Adjustment detailed in \"c\" and \"f\" above are offset by adjustments made to O&M costs.
h Adjustment to reclassify certain allocated costs totaling $5 million from O&M to Depreciation and Amortization.
i Adjustment to remove Synfuel results, which are not included in determining Merchant Below Gross Margin - $4 million in O&M, $6 million in D&A, $1 million in Fixed Charges,
and ($46 million) from income tax expense.
j Adjustment to remove Special Items, which are not included in determining Merchant Below Gross Margin.
k Adjustment to reflect management's view of these items as Other Income / Expense.
l Adjustment to move Interest Income of $7 million recorded in Other Income / Expense to Fixed Charges (to show a fixed charge amount net of interest income).
m Adjustment to remove tax benefit of $5 million related to gains on economic, non-qualifying hedges of gas transportation and storage contracts.
** Excludes $18 million of operating expenses, depreciation, depletion and amortization, and interest expense associated with our Upstream Gas properties
PROJECTED GROSS MARGIN AND RESULTS BELOW GROSS MARGIN:
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Constellation Energy is unable to reconcile its projected gross margin or results below gross margin to GAAP because we do not predict the future impact of
reconciling items or special items such as the cumulative effect of changes in accounting principles and the disposition of assets.

1Q06 Merchant Gross Margin and Below Gross Margin
We utilize the non-GAAP financial measure of Gross Margin to highlight the relationship between the costs of and prices for energy in our Merchant Energy
business categories (i.e., Mid-Atlantic Fleet, Plants with PPAs, Wholesale Competitive Supply, NewEnergy, and QFs/Other). We believe this non-GAAP measure
helps investors to better understand the changes in the level of our Merchant Energy operating results for these categories from period to period.
RECONCILIATION: Quarter Ended March 31, 2006
GAAP Adjustments Merchant
GAAP Fuel & Purchased In Arriving Gross Margin
Merchant Revenue & Expense Categories Revenues Energy Expenses Difference At Gross Margin Notes (Non-GAAP)
($ millions)
Mid-Atlantic Fleet $ 465.4 $ 366.1 $ 99.3 $ 13 a, b, c $ 112
Plants with PPAs 152.4 15.7 136.7 (5) a 131
Wholesale Competitive Supply 1,420.5 1,215.3 205.2 10 a , d, e 215 **
NewEnergy 2,024.2 1,950.9 73.3 2 d 75
QFs / Other 20.8 - 20.8 (4) e, f 17
Total Merchant $ 4,083.3 $ 3,548.0 $ 535.3 $ 16 $ 550
Adjustments Merchant Below
Arriving At Merchant Gross Margin
Total Merchant: GAAP Below Gross Margin (Non-GAAP)
Revenues less fuel and purchased energy expenses $ 535.3 $ 550
Operations and maintenance expenses (362.3) 15 g, h, i (346)
Merger related transaction costs (1.3) 1 j -
Workforce reduction costs (2.2) 2 j -
Depreciation, depletion, and amortization (64.1) 3 h, i (62)
Taxes other than income taxes (29.5) 30 k -
Accretion of asset retirement obligations (16.5) 17 k -
Income From Operations 59.4 142
Other income / (expense) 13.3 (50) b, i, k, l (37)
EBIT N/A 105
Fixed charges (47.4) 9l (38)
Income Before Income Taxes 25.3 67
Income tax expense 6.9 (32) i, m (26)
Income from Continuing Operations 32.2 41
Income from discontinued operations 11.4 (11) j -
Net Income $ 43.6 $ 41
Details of Adjustments Made in Arriving at Merchant Gross Margin:
a Adjustment to remove ($14 million) loss from Mid-Atlantic Fleet and $5 million gain from Plants with PPA's of estimated gross margin created through active portfolio
management more appropriately categorized as a competitive supply activity.
b Adjustment to remove $5 million of decommissioning revenues from non-GAAP gross margin measure and included in Other Income. The offsetting decommissioning expense
was recorded in accretion of asset retirement obligations.
c Adjustment to remove ($4 million) of other indirect costs have been removed from non-GAAP gross margin as they are more appropriately categorized as operating expenses.
d Adjustment to remove ($14 million) loss in Wholesale Competitive Supply and ($2 million) loss in NewEnergy related to economic, non-qualifying hedges of
fuel adjustment clauses and gas transport contracts
e Adjustment to remove synfuel losses from Wholesale Competitive Supply gross margin of ($6 million) and Other gross margin of ($7 million)
f Adjustment to reflect $11 million of direct costs in Other for purposes of non-GAAP gross margin measure.
Details of Adjustments Made in Arriving at Merchant Below Gross Margin:
g Adjustment detailed in \"c\" and \"f\" above are offset by adjustments made to O&M costs.
h Adjustment to reclassify certain allocated costs totaling $3 million from O&M to Depreciation and Amortization
i Adjustment to remove Synfuel results, which are not included in determining Merchant Below Gross Margin - $4 million in O&M, $6 million in D&A, $1 million in other expense,
and ($25 million) from income tax expense
j Adjustment to remove Special Items, which are not included in determining Merchant Below Gross Margin.
k Adjustment to reflect management's view of these items as Other Income / Expense.
l Adjustment to move Interest Income of $9 million recorded in Other Income / Expense to Fixed Charges (to show a fixed charge amount net of interest income).
m Adjustment to remove tax benefit ($7 million) related to losses on economic, non-qualifying hedges of fuel adjustment clauses and gas transport contracts and special items
** Excludes $12 million of operating expenses, depreciation, depletion and amortization, and interest expense associated with our Upstream Gas properties
PROJECTED GROSS MARGIN AND RESULTS BELOW GROSS MARGIN:
41
Constellation Energy is unable to reconcile its projected gross margin or results below gross margin to GAAP because we do not predict the future impact of
reconciling items or special items such as the cumulative effect of changes in accounting principles and the disposition of assets.

Cash Flows
The following is a reconciliation of the non-GAAP financial measures of Net Cash Flow before Debt Issuances/Payments and Free Cash Flow.
We utilize these non-GAAP measures because we believe they are helpful in understanding our ability to reduce debt by existing cash.
RECONCILIATION:
2007
($ millions)
QTD MARCH ACTUAL RESULTS:
Net cash used in operating activities (GAAP measure) 349
Adjustment to reflect operating use of cash in connection with contract acquisitions
as a financing use
Adjustment for derivative contracts presented as financing activities under SFAS 149 (2)
Adjusted Net Cash Used in Operating Activities $ 347 NON-GAAP MEASURE
Net cash used in investing activities (GAAP measure) (493)
Net Cash Used in Financing Activities (Excl. Debt-Related Sources & Uses) *
Common stock dividends paid (68)
Proceeds from issuance of common stock 22
Reacquisition of common stock (77)
Net proceeds from acquired contracts 27
Other financing activities, excluding SFAS 149 activities included in operating 6
Adjusted Net Cash Used in Financing Activities (90)
Net Cash Flow before Debt Issuances/(Payments) (236) NON-GAAP MEASURE
Less: Proceeds from issuance of common stock (22)
Add: Reacquisition of common stock 77
Add: Common stock dividends paid 68
Free Cash Flow $ (113) NON-GAAP MEASURE
* Total GAAP Cash Used in Financing Activities (incl. debt-related sources & uses) was $209 million QTD March 07.
PROJECTED CASH FLOWS:
Constellation Energy is unable to provide a reconciliation of these measures for Projected 2007 because it does not prepare a
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forecasted statement of cash flows on a GAAP basis.

Net Debt to Total Capital
Debt to Total Capital is a non-GAAP ratio that excludes unamortized discounts and premiums, reduces debt by our cash balance, and
includes minority interests in equity. In addition, we reflect a 50 percent equity credit for our trust preferred securities and remove the
non-economic impact commodity hedges and cash collateral held, similar to the evaluation performed by major credit rating agencies.
Management believes this non-GAAP measures provide investors useful information on our leverage because it is consistent with the
evaluation performed by rating agencies, takes into account minority equity interests in our consolidated affiliates and cash available to
reduce debt, and facilitates comparability between periods.
RECONCILIATION: March 31, 2007 December 31, 2006 December 31, 2005 December 31, 2001
GAAP GAAP
Balances Non-GAAP Ratio GAAP Balances Non-GAAP Ratio Balances Non-GAAP Ratio GAAP Balances Non-GAAP Ratio
($ millions)
Total long-term debt (gross of current portion) $ 4,741.5 $ 4,741.5 $ 4,849.3 $ 4,849.3 $ 4,610.9 $ 4,610.9 $ 3,874.4 $ 3,874.4
Fair value (increase) decrease in fixed to floating rate swap
included in long-term debt (1.6) 7.1 0.9 -
6.20% deferrable interest subordinated debentures due
October 15, 2043 to BGE wholly owned BGE Capital
Trust II relating to trust originated preferred securities 257.7 257.7 257.7 257.7 257.7 257.7 250.0 250.0
50% Equity credit to trust preferred securities - (125.0) - (125.0) - (125.0) - (125.0)
Adjustment to include High Desert Lease on Balance Sheet at
December 31, 2001 - - - - - - - 221.0
Short-term borrowings - - - - 0.7 0.7 975.0 975.0
Unamortized discount and premium (5.6) - (5.9) - (8.0) - (5.2) -
Subtotal 4,993.6 4,872.6 5,101.1 4,989.1 4,861.3 4,745.2 5,094.2 5,195.4
LESS: Cash - 1,936.6 - 2,289.1 - 813.0 - 72.4
Total Net Debt 4,993.6 2,936.0 33.7% 5,101.1 2,700.0 35.0% 4,861.3 3,932.2 42.8% 5,094.2 5,123.0 54.6%
BGE Preference Stock Not Subject To Mandatory
Redemption 190.0 190.0 190.0 190.0 190.0 190.0 190.0 190.0
Minority Interests - 90.1 - 94.5 - 22.4 - 101.8
Common shareholders' equity 5,373.3 5,373.3 4,611.7 4,611.7 4,915.5 4,915.5 3,843.6 3,843.6
Subtotal 5,563.3 5,653.4 4,801.7 4,896.2 5,105.5 5,127.9 4,033.6 4,135.4
50% Equity credit to trust preferred securities - 125.0 - 125.0 - 125.0 - 125.0
Total Equity 5,563.3 5,778.4 66.3% 4,801.7 5,021.2 65.0% 5,105.5 5,252.9 57.2% 4,033.6 4,260.4 45.4%
Total Capitalization $ 10,556.9 $ 8,714.4 100.0% $ 9,902.8 $ 7,721.2 100.0% $ 9,966.8 $ 9,185.1 100.0% $ 9,127.8 $ 9,383.4 100.0%
Exclude commodity hedge AOCI Balance from common
shareholders' equity 666 1,379 323 (30.0)
Counterparty cash collateral held reflected as a reduction of
cash balance (296) (253) (388) -
Adjusted Net Debt to Total Capital 33.4% 31.6% 43.7% 54.8%
PROJECTED LEVERAGE RATIOS:
Constellation Energy is unable to provide a reconciliation of this measure for Projected 2006 because it does not prepare a forecasted balance sheet on a GAAP basis.
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