Segments and Related Information (Tables)

12 Months Ended

Dec. 31, 2024

Dec. 31, 2023

Dec. 31, 2022

Segment Reporting [Abstract]

Results from Operations by Reportable Segment

NSP-Wisconsin’s consolidated operating revenues and net income:

	2024
(Millions of Dollars)	Regulated electric utility		Regulated natural gas utility		Total segments
Operating revenues (a)	$	995	$	135	$	1,130
Intersegment revenue	—		1		1
Total segment revenues	995		136		1,131
Electric fuel and purchased power	397		—		397
Cost of natural gas sold and transported	—		55		55
O&M expenses	201		28		229
Depreciation and amortization	156		30		186
Other segment expenses, net	29		5		34
Interest charges and financing costs	54		7		61
Income tax expense	37		2		39
Net income	$	121	$	9	$	130
Total segment revenues					$	1,131
Eliminate intersegment revenue					(1)
Non-segment revenues					1
Consolidated operating revenues					$	1,131
Total segment net income					$	130
Non-segment net income					4
Consolidated net income					$	134

(a)Operating revenues include $216 million of affiliate electric revenue. See Note 12 for further information.

	2023
(Millions of Dollars)	Regulated electric utility		Regulated natural gas utility		Total segments
Operating revenues (a)	$	1,019	$	157	$	1,176
Intersegment revenues	—		1		1
Total segment revenues	1,019		158		1,177
Electric fuel and purchased power	422		—		422
Cost of natural gas sold and transported	—		80		80
O&M expenses	210		28		238
Depreciation and amortization	142		28		170
Other segment expenses, net (b)	36		6		42
Interest charges and financing costs	45		5		50
Income tax expense	38		2		40
Net income	126		9		$	135
Total segment revenues					$	1,177
Eliminate intersegment revenue					(1)
Non-segment revenues					1
Consolidated operating revenues					$	1,177
Total segment net income					$	135
Non-segment net income					1
Consolidated net income					$	136

(a)Operating revenues include $204 million of affiliate electric revenue. See Note 12 for further information.

(b)Other segment expenses, net, for 2023 additionally includes workforce reduction expenses.

	2022
(Millions of Dollars)	Regulated electric utility		Regulated natural gas utility		Total segments
Operating revenues (a)	$	1,002	$	198	$	1,200
Electric fuel and purchased power	463		—		463
Cost of natural gas sold and transported	—		116		116
O&M expenses	202		23		225
Depreciation and amortization	131		27		158
Other segment expenses, net	34		5		39
Interest charges and financing costs	38		4		42
Income tax expense	29		6		35
Net income	105		17		$	122
Total segment revenues					$	1,200
Non-segment revenues					1
Consolidated operating revenues					$	1,201
Total segment net income					$	122
Non-segment net income					3
Consolidated net income					$	125

(a)Operating revenues include $202 million of affiliate electric revenue. See Note 12 for further information.