Income Taxes (Tables)

9 Months Ended

Sep. 30, 2011

Income Taxes

Income Tax Rate

	Three Months						Nine Months
	2011			2010			2011			2010
Alliant Energy		21.3	%		29.2	%		15.1	%		32.2	%
IPL		(3.3	%)		25.8	%		(1.7	%)		27.8	%
WPL		34.4	%		37.3	%		33.0	%		37.7	%

Production Tax Credits (Net Of State Tax Impacts)

	Three Months				Nine Months
	2011		2010		2011		2010
Cedar Ridge (WPL)	$	0.6	$	0.4	$	3.2	$	2.4
Bent Tree—Phase I (WPL)		1.4		—		6.7		—
Subtotal (WPL)		2.0		0.4		9.9		2.4
Whispering Willow—East (IPL)		1.8		1.0		8.2		4.5
	$	3.8	$	1.4	$	18.1	$	6.9

Net Operating Loss Carryforwards And Associated Deferred Tax Assets

	Carryforward Amount		Deferred Tax Assets (a)
Federal net operating losses	$	860	$	295
State net operating losses		623		32

(a) The gross net operating losses are offset by uncertain tax positions that if lost, will be settled in a reduction of net operating losses and not with tax payments. Alliant Energy's, IPL's and WPL's deferred tax assets related to federal and state net operating losses, net of offsets, were $272 million, $108 million and $116 million, respectively.