Investments

12 Months Ended

Dec. 31, 2023

Schedule of Equity Method Investments [Line Items]

Investments

INVESTMENTS

Unconsolidated Equity Investments - Alliant Energy’s unconsolidated investments accounted for under the equity method of accounting are as follows (in millions):

	Ownership Interest at	Carrying Value at December 31,		Equity (Income) / Loss
	December 31, 2023	2023	2022	2023	2022	2021
ATC Holdings	16%, 20%	$386	$358	($49)	($41)	($43)
Non-utility wind farm in Oklahoma	50%	104	101	(7)	(5)	(4)
Corporate venture investments	Various	74	62	(2)	(3)	(13)
Other	Various	21	21	(3)	(2)	(2)
		$585	$542	($61)	($51)	($62)

Summary aggregate financial information from the financial statements of these holdings is as follows (in millions):

	Alliant Energy
	2023	2022	2021
Revenues	$898	$813	$802
Operating income	384	350	357
Net income	370	675	358
As of December 31:
Current assets	221	227
Non-current assets	9,032	8,292
Current liabilities	528	620
Non-current liabilities	3,584	3,285
Noncontrolling interest	259	289

ATC Holdings - As of December 31, 2023, Alliant Energy has a 16% ownership interest in ATC and a 20% ownership interest in ATC Holdco LLC, collectively referred to as ATC Holdings. ATC is an independent, for-profit, transmission-only company. ATC Holdco LLC holds Duke-American Transmission Company, LLC, a joint venture between Duke Energy Corporation and ATC, that owns electric transmission infrastructure in North America. Refer to Note 17(g) for discussion of a reduction in earnings recorded in 2022 related to a court decision, which is currently expected to reduce the base return on equity authorized for MISO transmission owners, including ATC.

Non-utility Wind Farm in Oklahoma - The non-utility wind farm located in Oklahoma provides electricity to a third-party under a long-term PPA, and has both cash and tax equity ownership. Alliant Energy does not maintain or operate the wind farm, and provided a parent guarantee of its subsidiary’s indemnification obligations under the operating agreement and PPA. Refer to Note 17(d) for discussion of the guarantee.

Corporate Venture Investments - Alliant Energy has various minority ownership interests in regional and national venture funds, including a global coalition of energy companies working together to help advance the transition towards a cleaner, more sustainable, and inclusive energy future, by identifying and researching innovative technologies and business models within the emerging energy economy.