Property, Plant And Equipment

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Abstract]

(5) PROPERTY, PLANT AND EQUIPMENT

Property, plant and equipment at December 31 consisted of the following (dollars in millions):


	2023				2022				Lives (in years)
Electric Utilities	Property, Plant and Equipment			Weighted Average Useful Life (in years)	Property, Plant and Equipment			Weighted Average Useful Life (in years)	Minimum	Maximum
Electric plant:
Production	$	1,492.8		40	$	1,482.1		41	32	45
Electric transmission		737.4		48		632.9		48	42	51
Electric distribution		1,146.9		47		1,082.5		47	45	50
Integrated Generation		720.0		30		713.5		31	19	38
Plant acquisition adjustment (a)		4.9		32		4.9		32	32	32
General		291.7		27		274.8		27	24	28
Total electric plant in service		4,393.7				4,190.7
Construction work in progress		123.1				153.0
Total electric plant		4,516.8				4,343.7
Less accumulated depreciation and depletion		(1,207.7	)			(1,104.1	)
Electric plant net of accumulated depreciation and depletion	$	3,309.1			$	3,239.6

____________________

(a) The plant acquisition adjustment, which relates to the acquisition of our ownership interest in Wyodak Plant, is included in rate base and is being recovered with 7 years remaining.


	2023				2022				Lives (in years)
Gas Utilities	Property, Plant and Equipment			Weighted Average Useful Life (in years)	Property, Plant and Equipment			Weighted Average Useful Life (in years)	Minimum	Maximum
Gas plant:
Production	$	21.0		45	$	17.8		45	24	47
Gas transmission		759.5		58		695.4		58	32	72
Gas distribution		2,860.0		57		2,620.2		57	48	61
Cushion gas - not depreciable (a)		58.2		N/A		63.1		N/A	N/A	N/A
Storage		71.4		42		65.8		41	36	49
General		571.8		22		497.4		23	20	25
Total gas plant in service		4,341.9				3,959.7
Construction work in progress		39.2				52.0
Total gas plant		4,381.1				4,011.7
Less accumulated depreciation		(588.3	)			(471.0	)
Gas plant net of accumulated depreciation	$	3,792.8			$	3,540.7

____________________

(a) Depreciation of Cushion Gas is determined by the respective regulatory jurisdiction in which the Cushion Gas resides. In 2022, assets classified as Cushion gas - depreciable were fully depreciated and removed from gross plant in service and accumulated depreciation.


	2023				2022				Lives (in years)
Corporate	Property, Plant and Equipment			Weighted Average Useful Life (in years)	Property, Plant and Equipment			Weighted Average Useful Life (in years)	Minimum	Maximum
Total plant in service	$	5.7		10	$	5.7		11	4	23
Construction work in progress		13.6				13.7
Total gross property, plant and equipment		19.3				19.4
Less accumulated depreciation		(1.9	)			(1.8	)
Total net of accumulated depreciation	$	17.4			$	17.6