Property Plant and Equipment Property Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2024

Property, Plant and Equipment [Line Items]

Public Utility Property, Plant, and Equipment

Major classes of property, plant and equipment

(Millions of Dollars)	Dec. 31, 2024		Dec. 31, 2023
Property, plant and equipment, net
Electric plant	$	56,791	$	52,494
Natural gas plant	9,834		9,080
Common and other property	3,515		3,190
Plant to be retired (a)	1,793		2,055
CWIP	4,720		2,873
Total property, plant and equipment	76,653		69,692
Less accumulated depreciation	(19,852)		(18,399)
Nuclear fuel	3,491		3,337
Less accumulated amortization	(3,094)		(2,988)
Property, plant and equipment, net	$	57,198	$	51,642

(a)Amounts include Sherco 1 and 3 and A.S. King for NSP-Minnesota; Comanche Units 2 and 3, Craig Units 1 and 2, Hayden Units 1 and 2 and coal generation assets at Pawnee pending facility gas conversion for PSCo; and Tolk Unit 1 and 2 for SPS. The Dec. 31, 2023 amounts also include coal generation assets at Harrington, which were retired in 2024 and the conversion to natural gas is in process. Amounts are presented net of accumulated depreciation.

NSP Minnesota

Property, Plant and Equipment [Line Items]

Schedule of Jointly Owned Utility Plants

(Millions of Dollars, Except Percent Owned)	Plant in Service		Accumulated Depreciation		Percent Owned
NSP-Minnesota
Electric generation:
Sherco Unit 3	$	636	$	499	59	%
Sherco common facilities	189		128		80
Sherco substation	5		4		59
Electric transmission:
Grand Meadow	11		4		50
Huntley Wilmarth	49		3		50
CapX2020	855		160		51
Total NSP-Minnesota (a)	$	1,745	$	798

(a)Projects additionally include $10 million in CWIP.

NSP-Wisconsin

Property, Plant and Equipment [Line Items]

Schedule of Jointly Owned Utility Plants

(Millions of Dollars, Except Percent Owned)	Plant in Service		Accumulated Depreciation		Percent Owned
NSP-Wisconsin
Electric transmission:
La Crosse, WI to Madison, WI	$	179	$	30	37	%
CapX2020	169		44		80
Total NSP-Wisconsin (a)	$	348	$	74

(a)Projects additionally include $1 million in CWIP.

PSCo

Property, Plant and Equipment [Line Items]

Schedule of Jointly Owned Utility Plants

(Millions of Dollars, Except Percent Owned)	Plant in Service		Accumulated Depreciation		Percent Owned
PSCo
Electric generation:
Hayden Unit 1	$	158	$	117	76	%
Hayden Unit 2	152		93		37
Hayden common facilities	45		33		53
Craig Units 1 and 2	82		58		10
Craig common facilities	40		27		7
Comanche Unit 3	933		212		67
Comanche common facilities	29		5		77
Electric transmission:
Transmission and other facilities	190		75		Various
Gas transmission:
Rifle, CO to Avon, CO	28		10		60
Gas transmission compressor	8		3		50
Total PSCo (a)	$	1,665	$	633

(a)Projects additionally include $28 million in CWIP.