Commitments And Contingencies (Tables)

9 Months Ended

Sep. 30, 2024

Commitments and Contingencies [Line Items]

Other Purchase Commitments

At September 30, 2024, the related minimum future commitments, excluding amounts for purchased power commitments that do not have minimum thresholds but will require payment when electricity is generated by the provider, were as follows (in millions):

	Alliant Energy	IPL	WPL
Natural gas	$746	$322	$424
Coal	139	80	59
Other (a)	110	46	22
	$995	$448	$505

(a)Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2024.

MGP Site Estimated Future Costs And Recorded Liabilities

At September 30, 2024, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, which are not discounted, were as follows (in millions):

	Alliant Energy			IPL			WPL
Range of estimated future costs	$7	-	$28	$5	-	$17	$2	-	$11
Current and non-current environmental liabilities	$13			$8			$5

IPL [Member]

Commitments and Contingencies [Line Items]

Other Purchase Commitments

At September 30, 2024, the related minimum future commitments, excluding amounts for purchased power commitments that do not have minimum thresholds but will require payment when electricity is generated by the provider, were as follows (in millions):

	Alliant Energy	IPL	WPL
Natural gas	$746	$322	$424
Coal	139	80	59
Other (a)	110	46	22
	$995	$448	$505

(a)Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2024.

MGP Site Estimated Future Costs And Recorded Liabilities

At September 30, 2024, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, which are not discounted, were as follows (in millions):

	Alliant Energy			IPL			WPL
Range of estimated future costs	$7	-	$28	$5	-	$17	$2	-	$11
Current and non-current environmental liabilities	$13			$8			$5

WPL [Member]

Commitments and Contingencies [Line Items]

Other Purchase Commitments

At September 30, 2024, the related minimum future commitments, excluding amounts for purchased power commitments that do not have minimum thresholds but will require payment when electricity is generated by the provider, were as follows (in millions):

	Alliant Energy	IPL	WPL
Natural gas	$746	$322	$424
Coal	139	80	59
Other (a)	110	46	22
	$995	$448	$505

(a)Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2024.

MGP Site Estimated Future Costs And Recorded Liabilities

At September 30, 2024, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, which are not discounted, were as follows (in millions):

	Alliant Energy			IPL			WPL
Range of estimated future costs	$7	-	$28	$5	-	$17	$2	-	$11
Current and non-current environmental liabilities	$13			$8			$5