Property, Plant and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2016

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



	Depreciable
	Life	2016			2015
Regulated assets:
Utility generation, transmission and distribution systems	5-80 years	$	71,536		$	69,248
Interstate natural gas pipeline assets	3-80 years	6,942			6,755
		78,478			76,003
Accumulated depreciation and amortization		(23,603		)	(22,682		)
Regulated assets, net		54,875			53,321

Nonregulated assets:
Independent power plants	5-30 years	5,594			4,751
Other assets	3-30 years	1,002			875
		6,596			5,626
Accumulated depreciation and amortization		(1,060		)	(805		)
Nonregulated assets, net		5,536			4,821

Net operating assets		60,411			58,142
Construction work-in-progress		2,098			2,627
Property, plant and equipment, net		$	62,509		$	60,769

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



	Depreciable Life	2016			2015

Utility plant in service:
Generation	20-70 years	$	11,282		$	10,404
Transmission	52-75 years	1,726			1,305
Electric distribution	20-75 years	3,197			3,059
Gas distribution	28-70 years	1,565			1,507
Utility plant in service		17,770			16,275
Accumulated depreciation and amortization		(5,448		)	(5,229		)
Utility plant in service, net		12,322			11,046
Nonregulated property, net:
Nonregulated property gross	20-50 years	7			15
Accumulated depreciation and amortization		(1		)	(5		)
Nonregulated property, net		6			10
		12,328			11,056
Construction work-in-progress		493			667
Property, plant and equipment, net		$	12,821		$	11,723

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	2016			2015
Property, plant and equipment:
Generation	14 - 67 years	$	12,371		$	12,164
Transmission	58 - 75 years	6,055			5,914
Distribution	20 - 70 years	6,590			6,408
Intangible plant⁽¹⁾	5 - 62 years	884			875
Other	5 - 60 years	1,398			1,396
Property, plant and equipment in-service		27,298			26,757
Accumulated depreciation and amortization		(8,793		)	(8,360		)
Net property, plant and equipment in-service		18,505			18,397
Construction work-in-progress		657			629
Total property, plant and equipment, net		$	19,162		$	19,026


(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	2016			2015
Utility plant:
Generation	30 - 55 years	$	4,271		$	4,212
Distribution	20 - 65 years	3,231			3,118
Transmission	45 - 65 years	1,846			1,788
General and intangible plant	5 - 65 years	738			694
Utility plant		10,086			9,812
Accumulated depreciation and amortization		(3,205		)	(2,971		)
Utility plant, net		6,881			6,841
Other non-regulated, net of accumulated depreciation and amortization	45 years	2			2
Plant, net		6,883			6,843
Construction work-in-progress		114			153
Property, plant and equipment, net		$	6,997		$	6,996

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



	Depreciable Life	2016			2015
Utility plant:
Electric generation	30 - 60 years	$	1,137		$	1,134
Electric distribution	20 - 70 years	1,417			1,382
Electric transmission	50 - 70 years	771			739
Electric general and intangible plant	5 - 65 years	164			139
Natural gas distribution	40 - 70 years	381			374
Natural gas general and intangible plant	5 - 60 years	15			13
Common general	5 - 65 years	267			265
Utility plant		4,152			4,046
Accumulated depreciation and amortization		(1,442		)	(1,368		)
Utility plant, net		2,710			2,678
Other non-regulated, net of accumulated depreciation and amortization	60 years	5			—
Plant, net		2,715			2,678
Construction work-in-progress		107			88
Property, plant and equipment, net		$	2,822		$	2,766