Property, Plant and Equipment

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Property, Plant and Equipment

SCE's property, plant and equipment included in the consolidated balance sheets is composed of the following:

	December 31,
(in millions)	2016			2015
Distribution	$	22,332		$	20,871
Transmission	12,549			11,592
Generation	3,376			3,138
General plant and other	4,633			4,543
Accumulated depreciation	(9,000		)	(8,548		)
	33,890			31,596
Construction work in progress	2,790			3,218
Nuclear fuel, at amortized cost	126			131
Total utility property, plant and equipment	$	36,806		$	34,945

Capitalized Software Costs

SCE capitalizes costs incurred during the application development stage of internal use software projects to property, plant, and equipment. SCE amortizes capitalized software costs ratably over the expected lives of the software, ranging from 5 to 15 years and commencing upon operational use. Capitalized software costs, included in general plant and other above, were $1.4 billion at both December 31, 2016 and 2015 and accumulated amortization was $0.8 billion and $0.9 billion, at December 31, 2016 and 2015, respectively. Amortization expense for capitalized software was $249 million, $268 million and $271 million in 2016, 2015 and 2014, respectively. At December 31, 2016, amortization expense is estimated to be approximately $243 million annually for 2017 through 2021.

Jointly Owned Utility Projects

SCE owns undivided interests in several generating assets for which each participant provides its own financing. SCE's proportionate share of these assets is reflected in the consolidated balance sheets and included in the above table. SCE's proportionate share of expenses for each project is reflected in the consolidated statements of income. A portion of the investments in Palo Verde generating stations is included in regulatory assets on the consolidated balance sheets. For further information see Note 10.

The following is SCE's investment in each asset as of December 31, 2016:

(in millions)	Plant in Service		Construction Work in Progress		Accumulated Depreciation		Nuclear Fuel (at amortized cost)		Net Book Value		Ownership Interest
Transmission systems:
Eldorado	$	235	$	10	$	21	$	—	$	224	59%
Pacific Intertie	192		21		80		—		133		50%
Generating station:
Palo Verde (nuclear)	1,959		62		1,547		126		600		16%
Total	$	2,386	$	93	$	1,648	$	126	$	957

In addition, SCE has ownership interests in jointly owned power poles with other companies.