Jointly-Owned Electric Utility Plant (Tables)

12 Months Ended

Dec. 31, 2021

Jointly Owned Electric Utility Plant [Line Items]

Components of Jointly-Owned Electric Utility Plants

Information relative to IPL’s and WPL’s ownership interest in these jointly-owned EGUs at December 31, 2021 was as follows (dollars in millions):

	Ownership	Electric	Accumulated Provision	Construction
	Interest %	Plant	for Depreciation	Work in Progress
IPL
Ottumwa Unit 1	48.0%	$599	$214	$11
George Neal Unit 4	25.7%	193	100	2
George Neal Unit 3	28.0%	173	74	3
Louisa Unit 1	4.0%	40	23	—
		1,005	411	16
WPL
Columbia Units 1-2	53.5%	802	314	6
West Riverside Energy Center and Solar Garden	91.0%	706	33	3
Forward Wind Energy Center	42.6%	118	48	—
		1,626	395	9
Alliant Energy		$2,631	$806	$25

IPL [Member]

Jointly Owned Electric Utility Plant [Line Items]

Components of Jointly-Owned Electric Utility Plants

Information relative to IPL’s and WPL’s ownership interest in these jointly-owned EGUs at December 31, 2021 was as follows (dollars in millions):

	Ownership	Electric	Accumulated Provision	Construction
	Interest %	Plant	for Depreciation	Work in Progress
IPL
Ottumwa Unit 1	48.0%	$599	$214	$11
George Neal Unit 4	25.7%	193	100	2
George Neal Unit 3	28.0%	173	74	3
Louisa Unit 1	4.0%	40	23	—
		1,005	411	16
WPL
Columbia Units 1-2	53.5%	802	314	6
West Riverside Energy Center and Solar Garden	91.0%	706	33	3
Forward Wind Energy Center	42.6%	118	48	—
		1,626	395	9
Alliant Energy		$2,631	$806	$25

WPL [Member]

Jointly Owned Electric Utility Plant [Line Items]

Components of Jointly-Owned Electric Utility Plants

Information relative to IPL’s and WPL’s ownership interest in these jointly-owned EGUs at December 31, 2021 was as follows (dollars in millions):

	Ownership	Electric	Accumulated Provision	Construction
	Interest %	Plant	for Depreciation	Work in Progress
IPL
Ottumwa Unit 1	48.0%	$599	$214	$11
George Neal Unit 4	25.7%	193	100	2
George Neal Unit 3	28.0%	173	74	3
Louisa Unit 1	4.0%	40	23	—
		1,005	411	16
WPL
Columbia Units 1-2	53.5%	802	314	6
West Riverside Energy Center and Solar Garden	91.0%	706	33	3
Forward Wind Energy Center	42.6%	118	48	—
		1,626	395	9
Alliant Energy		$2,631	$806	$25