Exelon Generation S-3ASR Automatic shelf registration

Exhibit 12.3

PECO Energy Company

Ratio of Earnings to Fixed Charges

	Years Ended December 31,
	2005		2006		2007		2008		2009
Pre-tax income from continuing operations before adjustment for income or loss from equity investees and minority interest	767		621		737		475		499
Plus: Loss from equity investees	16		9		7		16		24
Less: Capitalized interest	(1	)	(3	)	(3	)	(3	)	(2	)
Pre-tax income from continuing operations after adjustment for income or loss from equity investees, minority interest, and capitalized interest	782		627		741		488		521
Fixed charges:
Interest expensed and capitalized, amortization of debt discount and premium on all indebtness	280		269		251		229		185	(a)
Interest component of rental expense (b)	1		1		6		9		9
Total fixed charges	281		270		257		238		194
Pre-tax income from continuing operations after adjustment for income or loss from equity investees and capitalized interest plus fixed charges	1,063		897		998		726		715
Ratio of earnings to fixed charges	3.8		3.3		3.9		3.1		3.7

(a) Includes interest expense of $0, $0 and $0 million for the years ended December 31, 2009, 2008 and 2007, respectively, related to uncertain income tax positions.

(b) Represents one-third of rental expense relating to operating leases, which is a reasonable approximation of the interest factor.