Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2014

Property, Plant and Equipment [Line Items]

Property, Plant and Equipment

At December 31, details of property, plant and equipment on the balance sheets were as follows (in millions):

	Alliant Energy						IPL						WPL
	2014			2013			2014			2013			2014			2013
Utility:
Electric plant:
In service:
Generation (a)		$5,463.0			$4,792.0			$2,872.4			$2,513.2			$2,590.6			$2,278.8
Distribution	4,435.4			4,179.6			2,471.7			2,311.2			1,963.7			1,868.4
Other	309.1			286.3			215.5			210.5			93.6			75.8
Anticipated to be retired early (b)	157.6			157.8			—			—			157.6			157.8
Total electric plant	10,365.1			9,415.7			5,559.6			5,034.9			4,805.5			4,380.8
Gas plant in service	946.2			909.9			474.0			456.8			472.2			453.1
Other plant in service	539.3			547.9			298.8			302.8			240.5			245.1
Accumulated depreciation	(3,923.1		)	(3,726.2		)	(2,124.5		)	(2,025.3		)	(1,798.6		)	(1,700.9		)
Net plant	7,927.5			7,147.3			4,207.9			3,769.2			3,719.6			3,378.1
Leased Sheboygan Falls Energy Facility, net (c)	—			—			—			—			64.7			70.9
Construction work in progress	479.1			677.9			325.0			346.4			154.1			331.5
Other, net	22.3			22.3			21.8			21.2			0.5			1.1
Total utility	8,428.9			7,847.5			4,554.7			4,136.8			3,938.9			3,781.6
Non-regulated and other:
Non-regulated Generation, net (d)	240.1			249.4			—			—			—			—
Corporate Services and other, net (e)	269.4			229.6			—			—			—			—
Total non-regulated and other	509.5			479.0			—			—			—			—
Total property, plant and equipment		$8,938.4			$8,326.5			$4,554.7			$4,136.8			$3,938.9			$3,781.6

(a) Includes various emission controls projects placed in service in 2014, which are discussed in “Emission Controls Projects” below.

(b) In 2013, WPL received approval from MISO to retire Edgewater Unit 3, and Nelson Dewey Units 1 and 2. WPL currently anticipates retiring these EGUs by December 31, 2015, contingent on completion of transmission network upgrades needed for system reliability. WPL is recovering the remaining net book value of these EGUs over a 10-year period beginning January 1, 2013 pursuant to a May 2012 PSCW order.

(c) Less accumulated amortization of $59.1 million and $52.9 million for WPL as of December 31, 2014 and 2013, respectively.

(d) Less accumulated depreciation of $49.5 million and $40.0 million for Alliant Energy as of December 31, 2014 and 2013, respectively.

(e) Less accumulated depreciation of $229.1 million and $214.2 million for Alliant Energy as of December 31, 2014 and 2013, respectively.

Schedule Of Allowance For Funds Used During Construction

The amount of AFUDC generated by equity and debt components was as follows (in millions):

	Alliant Energy						IPL						WPL
	2014		2013		2012		2014		2013		2012		2014		2013		2012
Equity		$23.1		$20.3		$14.1		$17.1		$13.8		$5.2		$6.0		$6.5		$8.9
Debt	11.7		10.5		7.8		8.8		7.2		3.2		2.9		3.3		4.6
		$34.8		$30.8		$21.9		$25.9		$21.0		$8.4		$8.9		$9.8		$13.5

Schedule Of Allowance for Funds Used During Construction By Project

AFUDC related to various construction projects was recognized in the income statements as follows (in millions):

	2014		2013		2012
IPL:
Emission controls - Ottumwa Unit 1		$10.6		$8.0		$2.0
Emission controls - George Neal Units 3 and 4	1.4		5.1		0.9
Marshalltown	3.7		—		—
Other	10.2		7.9		5.5
	25.9		21.0		8.4
WPL:
Emission controls - Columbia Units 1 and 2	4.0		7.2		3.9
Emission controls - Edgewater Unit 5	2.7		—		7.2
Other	2.2		2.6		2.4
	8.9		9.8		13.5
Alliant Energy		$34.8		$30.8		$21.9

IPL [Member]

Property, Plant and Equipment [Line Items]

Property, Plant and Equipment

At December 31, details of property, plant and equipment on the balance sheets were as follows (in millions):

	Alliant Energy						IPL						WPL
	2014			2013			2014			2013			2014			2013
Utility:
Electric plant:
In service:
Generation (a)		$5,463.0			$4,792.0			$2,872.4			$2,513.2			$2,590.6			$2,278.8
Distribution	4,435.4			4,179.6			2,471.7			2,311.2			1,963.7			1,868.4
Other	309.1			286.3			215.5			210.5			93.6			75.8
Anticipated to be retired early (b)	157.6			157.8			—			—			157.6			157.8
Total electric plant	10,365.1			9,415.7			5,559.6			5,034.9			4,805.5			4,380.8
Gas plant in service	946.2			909.9			474.0			456.8			472.2			453.1
Other plant in service	539.3			547.9			298.8			302.8			240.5			245.1
Accumulated depreciation	(3,923.1		)	(3,726.2		)	(2,124.5		)	(2,025.3		)	(1,798.6		)	(1,700.9		)
Net plant	7,927.5			7,147.3			4,207.9			3,769.2			3,719.6			3,378.1
Leased Sheboygan Falls Energy Facility, net (c)	—			—			—			—			64.7			70.9
Construction work in progress	479.1			677.9			325.0			346.4			154.1			331.5
Other, net	22.3			22.3			21.8			21.2			0.5			1.1
Total utility	8,428.9			7,847.5			4,554.7			4,136.8			3,938.9			3,781.6
Non-regulated and other:
Non-regulated Generation, net (d)	240.1			249.4			—			—			—			—
Corporate Services and other, net (e)	269.4			229.6			—			—			—			—
Total non-regulated and other	509.5			479.0			—			—			—			—
Total property, plant and equipment		$8,938.4			$8,326.5			$4,554.7			$4,136.8			$3,938.9			$3,781.6

(a) Includes various emission controls projects placed in service in 2014, which are discussed in “Emission Controls Projects” below.

(b) In 2013, WPL received approval from MISO to retire Edgewater Unit 3, and Nelson Dewey Units 1 and 2. WPL currently anticipates retiring these EGUs by December 31, 2015, contingent on completion of transmission network upgrades needed for system reliability. WPL is recovering the remaining net book value of these EGUs over a 10-year period beginning January 1, 2013 pursuant to a May 2012 PSCW order.

(c) Less accumulated amortization of $59.1 million and $52.9 million for WPL as of December 31, 2014 and 2013, respectively.

(d) Less accumulated depreciation of $49.5 million and $40.0 million for Alliant Energy as of December 31, 2014 and 2013, respectively.

(e) Less accumulated depreciation of $229.1 million and $214.2 million for Alliant Energy as of December 31, 2014 and 2013, respectively.

Schedule Of Allowance For Funds Used During Construction

The amount of AFUDC generated by equity and debt components was as follows (in millions):

	Alliant Energy						IPL						WPL
	2014		2013		2012		2014		2013		2012		2014		2013		2012
Equity		$23.1		$20.3		$14.1		$17.1		$13.8		$5.2		$6.0		$6.5		$8.9
Debt	11.7		10.5		7.8		8.8		7.2		3.2		2.9		3.3		4.6
		$34.8		$30.8		$21.9		$25.9		$21.0		$8.4		$8.9		$9.8		$13.5

Schedule Of Allowance for Funds Used During Construction By Project

AFUDC related to various construction projects was recognized in the income statements as follows (in millions):

	2014		2013		2012
IPL:
Emission controls - Ottumwa Unit 1		$10.6		$8.0		$2.0
Emission controls - George Neal Units 3 and 4	1.4		5.1		0.9
Marshalltown	3.7		—		—
Other	10.2		7.9		5.5
	25.9		21.0		8.4
WPL:
Emission controls - Columbia Units 1 and 2	4.0		7.2		3.9
Emission controls - Edgewater Unit 5	2.7		—		7.2
Other	2.2		2.6		2.4
	8.9		9.8		13.5
Alliant Energy		$34.8		$30.8		$21.9

WPL [Member]

Property, Plant and Equipment [Line Items]

Property, Plant and Equipment

At December 31, details of property, plant and equipment on the balance sheets were as follows (in millions):

	Alliant Energy						IPL						WPL
	2014			2013			2014			2013			2014			2013
Utility:
Electric plant:
In service:
Generation (a)		$5,463.0			$4,792.0			$2,872.4			$2,513.2			$2,590.6			$2,278.8
Distribution	4,435.4			4,179.6			2,471.7			2,311.2			1,963.7			1,868.4
Other	309.1			286.3			215.5			210.5			93.6			75.8
Anticipated to be retired early (b)	157.6			157.8			—			—			157.6			157.8
Total electric plant	10,365.1			9,415.7			5,559.6			5,034.9			4,805.5			4,380.8
Gas plant in service	946.2			909.9			474.0			456.8			472.2			453.1
Other plant in service	539.3			547.9			298.8			302.8			240.5			245.1
Accumulated depreciation	(3,923.1		)	(3,726.2		)	(2,124.5		)	(2,025.3		)	(1,798.6		)	(1,700.9		)
Net plant	7,927.5			7,147.3			4,207.9			3,769.2			3,719.6			3,378.1
Leased Sheboygan Falls Energy Facility, net (c)	—			—			—			—			64.7			70.9
Construction work in progress	479.1			677.9			325.0			346.4			154.1			331.5
Other, net	22.3			22.3			21.8			21.2			0.5			1.1
Total utility	8,428.9			7,847.5			4,554.7			4,136.8			3,938.9			3,781.6
Non-regulated and other:
Non-regulated Generation, net (d)	240.1			249.4			—			—			—			—
Corporate Services and other, net (e)	269.4			229.6			—			—			—			—
Total non-regulated and other	509.5			479.0			—			—			—			—
Total property, plant and equipment		$8,938.4			$8,326.5			$4,554.7			$4,136.8			$3,938.9			$3,781.6

(a) Includes various emission controls projects placed in service in 2014, which are discussed in “Emission Controls Projects” below.

(b) In 2013, WPL received approval from MISO to retire Edgewater Unit 3, and Nelson Dewey Units 1 and 2. WPL currently anticipates retiring these EGUs by December 31, 2015, contingent on completion of transmission network upgrades needed for system reliability. WPL is recovering the remaining net book value of these EGUs over a 10-year period beginning January 1, 2013 pursuant to a May 2012 PSCW order.

(c) Less accumulated amortization of $59.1 million and $52.9 million for WPL as of December 31, 2014 and 2013, respectively.

(d) Less accumulated depreciation of $49.5 million and $40.0 million for Alliant Energy as of December 31, 2014 and 2013, respectively.

(e) Less accumulated depreciation of $229.1 million and $214.2 million for Alliant Energy as of December 31, 2014 and 2013, respectively.

Schedule Of Allowance For Funds Used During Construction

The amount of AFUDC generated by equity and debt components was as follows (in millions):

	Alliant Energy						IPL						WPL
	2014		2013		2012		2014		2013		2012		2014		2013		2012
Equity		$23.1		$20.3		$14.1		$17.1		$13.8		$5.2		$6.0		$6.5		$8.9
Debt	11.7		10.5		7.8		8.8		7.2		3.2		2.9		3.3		4.6
		$34.8		$30.8		$21.9		$25.9		$21.0		$8.4		$8.9		$9.8		$13.5

Schedule Of Allowance for Funds Used During Construction By Project

AFUDC related to various construction projects was recognized in the income statements as follows (in millions):

	2014		2013		2012
IPL:
Emission controls - Ottumwa Unit 1		$10.6		$8.0		$2.0
Emission controls - George Neal Units 3 and 4	1.4		5.1		0.9
Marshalltown	3.7		—		—
Other	10.2		7.9		5.5
	25.9		21.0		8.4
WPL:
Emission controls - Columbia Units 1 and 2	4.0		7.2		3.9
Emission controls - Edgewater Unit 5	2.7		—		7.2
Other	2.2		2.6		2.4
	8.9		9.8		13.5
Alliant Energy		$34.8		$30.8		$21.9