Property, Plant and Equipment, Net (Tables)

Property, plant and equipment, net consists of the following as of December 31 (in millions):



	Depreciable
	Life	2019			2018
Regulated assets:
Utility generation, transmission and distribution systems	5-80 years	$	81,127		$	76,707
Interstate natural gas pipeline assets	3-80 years	8,165			7,524
		89,292			84,231
Accumulated depreciation and amortization		(26,353		)	(25,894		)
Regulated assets, net		62,939			58,337

Nonregulated assets:
Independent power plants	5-30 years	6,983			6,826
Other assets	3-30 years	1,834			1,424
		8,817			8,250
Accumulated depreciation and amortization		(2,183		)	(1,610		)
Nonregulated assets, net		6,634			6,640

Net operating assets		69,573			64,977
Construction work-in-progress		3,732			3,110
Property, plant and equipment, net		$	73,305		$	68,087

Property, plant and equipment, net consists of the following as of December 31 (in millions):



	Depreciable Life	2019			2018

Utility plant in service:
Generation	20-70 years	$	15,687		$	13,727
Transmission	52-75 years	2,124			1,934
Electric distribution	20-75 years	4,095			3,672
Natural gas distribution	29-75 years	1,820			1,724
Utility plant in service		23,726			21,057
Accumulated depreciation and amortization		(6,139		)	(5,941		)
Utility plant in service, net		17,587			15,116
Nonregulated property, net:
Nonregulated property gross	20-50 years	7			7
Accumulated depreciation and amortization		(1		)	(1		)
Nonregulated property, net		6			6
		17,593			15,122
Construction work-in-progress		782			1,035
Property, plant and equipment, net		$	18,375		$	16,157

The average depreciation and amortization rates applied to depreciable utility plant for the years ended December 31 were as follows:

Property, plant and equipment, net consists of the following as of December 31 (in millions):



	Depreciable Life	2019			2018
Utility Plant:
Generation	14 - 67 years	$	12,509		$	12,606
Transmission	58 - 75 years	6,482			6,357
Distribution	20 - 70 years	7,307			7,030
Intangible plant⁽¹⁾	5 - 75 years	1,016			970
Other	5 - 60 years	1,449			1,436
Utility plant in service		28,763			28,399
Accumulated depreciation and amortization		(9,803		)	(10,034		)
Utility plant in service, net		18,960			18,365
Other non-regulated, net of accumulated depreciation and amortization	46 years	10			10
Plant, net		18,970			18,375
Construction work-in-progress		2,003			1,195
Property, plant and equipment, net		$	20,973		$	19,570


(1)	Computer software costs included in intangible plant are initially assigned a depreciable life of 5 to 10 years.

Property, plant and equipment, net consists of the following as of December 31 (in millions):



	Depreciable Life	2019			2018
Utility plant:
Generation	30 - 55 years	$	3,541		$	3,720
Distribution	20 - 65 years	3,567			3,411
Transmission	45 - 70 years	1,444			1,439
General and intangible plant	5 - 65 years	741			716
Utility plant		9,293			9,286
Accumulated depreciation and amortization		(2,951		)	(2,966		)
Utility plant, net		6,342			6,320
Other non-regulated, net of accumulated depreciation and amortization	45 years	1			1
Plant, net		6,343			6,321
Construction work-in-progress		195			97
Property, plant and equipment, net		$	6,538		$	6,418

Property, plant and equipment, net consists of the following as of December 31 (in millions):



	Depreciable Life	2019			2018
Utility plant:
Electric generation	25 - 60 years	$	1,133		$	1,132
Electric distribution	20 - 100 years	1,669			1,568
Electric transmission	50 - 100 years	840			812
Electric general and intangible plant	5 - 70 years	178			185
Natural gas distribution	35 - 70 years	417			403
Natural gas general and intangible plant	5 - 70 years	14			14
Common general	5 - 70 years	338			321
Utility plant		4,589			4,435
Accumulated depreciation and amortization		(1,629		)	(1,583		)
Utility plant, net		2,960			2,852
Other non-regulated, net of accumulated depreciation and amortization	70 years	2			5
Plant, net		2,962			2,857
Construction work-in-progress		113			90
Property, plant and equipment, net		$	3,075		$	2,947