Property, Plant and Equipment (Notes)

12 Months Ended

Dec. 31, 2014

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

PROPERTY, PLANT AND EQUIPMENT

Summary of property by classification as of December 31:

	2014			2013
	(In millions)
Property, Plant and Equipment
DTE Electric
Generation	$	11,641		$	11,127
Distribution	8,164			7,603
Total DTE Electric	19,805			18,730
DTE Gas
Distribution	2,946			2,834
Storage	448			431
Other	863			836
Total DTE Gas	4,257			4,101
Non-utility and other	2,476			2,292
Total	26,538			25,123
Less Accumulated Depreciation, Depletion and Amortization
DTE Electric
Generation	(4,149		)	(4,004		)
Distribution	(3,067		)	(2,947		)
Total DTE Electric	(7,216		)	(6,951		)
DTE Gas
Distribution	(1,130		)	(1,129		)
Storage	(142		)	(138		)
Other	(363		)	(338		)
Total DTE Gas	(1,635		)	(1,605		)
Non-utility and other	(867		)	(767		)
Total	(9,718		)	(9,323		)
Net Property, Plant and Equipment	$	16,820		$	15,800

AFUDC and interest capitalized was approximately $37 million and $33 million for the years ended December 31, 2014 and 2013, respectively.

The composite depreciation rate for DTE Electric was approximately 3.4% in 2014 and 2013 and 3.3% in 2012. The composite depreciation rate for DTE Gas was 2.4% in 2014, 2013 and 2012. The average estimated useful life for each major class of utility property, plant and equipment as of December 31, 2014 follows:

	Estimated Useful Lives in Years
Utility	Generation	Distribution	Storage
Electric	40	41	N/A
Gas	N/A	50	53

The estimated useful lives for major classes of non-utility assets and facilities range from 3 to 55 years.

Capitalized software costs are classified as Property, plant and equipment and the related amortization is included in Accumulated depreciation, depletion and amortization on the Consolidated Statements of Financial Position. The Company capitalizes the costs associated with computer software it develops or obtains for use in its business. The Company amortizes capitalized software costs on a straight-line basis over the expected period of benefit, ranging from 3 to 15 years.

Capitalized software costs amortization expense was $77 million in 2014, $71 million in 2013 and $68 million in 2012. The gross carrying amount and accumulated amortization of capitalized software costs at December 31, 2014 were $668 million and $335 million, respectively. The gross carrying amount and accumulated amortization of capitalized software costs at December 31, 2013 were $611 million and $323 million, respectively.

Gross property under capital leases was $35 million at December 31, 2014 and 2013. Accumulated amortization of property under capital leases was $27 million and $21 million at December 31, 2014 and 2013, respectively.