Regulatory Matters (Tables)

6 Months Ended

Jun. 30, 2022

Regulatory Assets [Line Items]

Regulatory Assets

Regulatory assets were comprised of the following items (in millions):

	Alliant Energy		IPL		WPL
	June 30, 2022	December 31, 2021	June 30, 2022	December 31, 2021	June 30, 2022	December 31, 2021
Tax-related	$954	$934	$903	$884	$51	$50
Pension and OPEB costs	445	462	220	228	225	234
Asset retirement obligations	140	128	99	89	41	39
Derivatives	101	8	69	4	32	4
Commodity cost recovery	88	42	2	2	86	40
Assets retired early	82	92	61	66	21	26
IPL’s DAEC PPA amendment	78	90	78	90	—	—
WPL’s Western Wisconsin gas distribution expansion investments	50	52	—	—	50	52
Other	113	132	58	80	55	52
	$2,051	$1,940	$1,490	$1,443	$561	$497

Regulatory Liabilities

Regulatory liabilities were comprised of the following items (in millions):

	Alliant Energy		IPL		WPL
	June 30, 2022	December 31, 2021	June 30, 2022	December 31, 2021	June 30, 2022	December 31, 2021
Tax-related	$573	$585	$308	$312	$265	$273
Cost of removal obligations	396	384	258	252	138	132
Derivatives	288	166	153	77	135	89
WPL’s West Riverside liquidated damages	34	36	—	—	34	36
Electric transmission cost recovery	31	51	11	27	20	24
Other	41	49	21	23	20	26
	$1,363	$1,271	$751	$691	$612	$580

IPL [Member]

Regulatory Assets [Line Items]

Regulatory Assets

Regulatory assets were comprised of the following items (in millions):

	Alliant Energy		IPL		WPL
	June 30, 2022	December 31, 2021	June 30, 2022	December 31, 2021	June 30, 2022	December 31, 2021
Tax-related	$954	$934	$903	$884	$51	$50
Pension and OPEB costs	445	462	220	228	225	234
Asset retirement obligations	140	128	99	89	41	39
Derivatives	101	8	69	4	32	4
Commodity cost recovery	88	42	2	2	86	40
Assets retired early	82	92	61	66	21	26
IPL’s DAEC PPA amendment	78	90	78	90	—	—
WPL’s Western Wisconsin gas distribution expansion investments	50	52	—	—	50	52
Other	113	132	58	80	55	52
	$2,051	$1,940	$1,490	$1,443	$561	$497

Regulatory Liabilities

Regulatory liabilities were comprised of the following items (in millions):

	Alliant Energy		IPL		WPL
	June 30, 2022	December 31, 2021	June 30, 2022	December 31, 2021	June 30, 2022	December 31, 2021
Tax-related	$573	$585	$308	$312	$265	$273
Cost of removal obligations	396	384	258	252	138	132
Derivatives	288	166	153	77	135	89
WPL’s West Riverside liquidated damages	34	36	—	—	34	36
Electric transmission cost recovery	31	51	11	27	20	24
Other	41	49	21	23	20	26
	$1,363	$1,271	$751	$691	$612	$580

WPL [Member]

Regulatory Assets [Line Items]

Regulatory Assets

Regulatory assets were comprised of the following items (in millions):

	Alliant Energy		IPL		WPL
	June 30, 2022	December 31, 2021	June 30, 2022	December 31, 2021	June 30, 2022	December 31, 2021
Tax-related	$954	$934	$903	$884	$51	$50
Pension and OPEB costs	445	462	220	228	225	234
Asset retirement obligations	140	128	99	89	41	39
Derivatives	101	8	69	4	32	4
Commodity cost recovery	88	42	2	2	86	40
Assets retired early	82	92	61	66	21	26
IPL’s DAEC PPA amendment	78	90	78	90	—	—
WPL’s Western Wisconsin gas distribution expansion investments	50	52	—	—	50	52
Other	113	132	58	80	55	52
	$2,051	$1,940	$1,490	$1,443	$561	$497

Regulatory Liabilities

Regulatory liabilities were comprised of the following items (in millions):

	Alliant Energy		IPL		WPL
	June 30, 2022	December 31, 2021	June 30, 2022	December 31, 2021	June 30, 2022	December 31, 2021
Tax-related	$573	$585	$308	$312	$265	$273
Cost of removal obligations	396	384	258	252	138	132
Derivatives	288	166	153	77	135	89
WPL’s West Riverside liquidated damages	34	36	—	—	34	36
Electric transmission cost recovery	31	51	11	27	20	24
Other	41	49	21	23	20	26
	$1,363	$1,271	$751	$691	$612	$580