ComEd 2006 Annual Report Download - page 192

Exelon Corporation and Subsidiary Companies
Exelon Generation Company, LLC and Subsidiary Companies
Commonwealth Edison Company and Subsidiary Companies
PECO Energy Company and Subsidiary Companies
Combined Notes to Consolidated Financial Statements—(Continued)
(Dollars in millions, except per share data unless otherwise noted)
Capitalized Software Costs (Exelon, Generation, ComEd and PECO)
Costs incurred during the application development stage of software projects that are developed
or obtained for internal use are capitalized. Such capitalized amounts are amortized ratably over the
expected lives of the projects when they become operational, generally not to exceed ten years.
Certain capitalized software costs are being amortized over five to fifteen years pursuant to regulatory
approval. The following table presents net unamortized capitalized software costs and amortization of
capitalized software costs by year:
Net unamortized software costs Exelon Generation ComEd PECO
December 31, 2006 ....................................... $295 $46 $118 $63
December 31, 2005 ....................................... 264 31 122 30
Amortization of capitalized software costs Exelon Generation ComEd PECO
2006 ................................................... $77 $13 $21 $22
2005 ................................................... 76 11 22 23
2004 ................................................... 80 16 34 12
Depreciation and Amortization (Exelon, Generation, ComEd and PECO)
Depreciation is generally provided over the estimated service lives of property, plant and
equipment on a straight-line basis using the composite method. ComEd’s depreciation includes a
provision for estimated removal costs as authorized by the ICC. Annual depreciation provisions for
financial reporting purposes, presented by average service life and as a percentage of average service
life for each asset category, are presented in the tables below. See Note 6—Property, Plant and
Equipment for information regarding a change in PECO’s depreciation rates.
Average Service Life in Years by Asset Category Exelon Generation ComEd PECO
2006
Electric—transmission and distribution ........................ 5-75 N/A 5-75 5-65
Electric—generation ....................................... 5-61 5-61 N/A N/A
Gas .................................................... 5-66 N/A N/A 5-66
Common—electric and gas ................................. 5-50 N/A N/A 5-50
Average Service Life in Years by Asset Category Exelon Generation ComEd PECO
2005
Electric—transmission and distribution ........................ 5-75 N/A 5-75 5-65
Electric—generation ....................................... 5-62 5-62 N/A N/A
Gas .................................................... 5-85 N/A N/A 5-85
Common—electric and gas ................................. 5-46 N/A N/A 5-46
Average Service Life in Years by Asset Category Exelon Generation ComEd PECO
2004
Electric—transmission and distribution ........................ 5-75 N/A 5-75 5-65
Electric—generation ....................................... 5-63 5-63 N/A N/A
Gas .................................................... 5-85 N/A N/A 5-85
Common—electric and gas ................................. 5-46 N/A N/A 5-46
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