Exhibit 12.2

INTERSTATE POWER AND LIGHT COMPANY

RATIO OF EARNINGS TO FIXED CHARGES AND RATIO OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED DIVIDEND REQUIREMENTS

	Year Ended December 31,
	2017			2016			2015			2014			2013
	(dollars in millions)
EARNINGS:
Net income		$227.0			$225.8			$196.2			$191.8			$188.3
Income tax benefit (a)	(10.9		)	(5.9		)	(22.7		)	(48.9		)	(36.3		)
Income before income taxes	216.1			219.9			173.5			142.9			152.0
Fixed charges as defined	113.0			103.7			97.2			91.0			82.3
Total earnings as defined		$329.1			$323.6			$270.7			$233.9			$234.3
FIXED CHARGES:
Interest expense		$112.4			$103.2			$96.8			$89.9			$81.3
Estimated interest component of rent expense	0.6			0.5			0.4			1.1			1.0
Total fixed charges as defined		$113.0			$103.7			$97.2			$91.0			$82.3
Ratio of Earnings to Fixed Charges	2.91			3.12			2.78			2.57			2.85
Preferred dividend requirements (pre-tax basis) (b)		$9.7			$9.9			$9.0			$7.6			$8.7
Fixed charges and preferred dividend requirements		$122.7			$113.6			$106.2			$98.6			$91.0
Ratio of Earnings to Combined Fixed Charges and Preferred Dividend Requirements	2.68			2.85			2.55			2.37			2.57

(a) Includes net interest related to unrecognized tax benefits.

(b) Preferred dividend requirements (pre-tax basis) are computed by dividing the preferred dividend requirements by one hundred percent minus the respective annual effective income tax rate. Excludes the impact of charges related to Interstate Power and Light Company’s preferred stock redemption in 2013.