Property, Plant, and Equipment

12 Months Ended

Dec. 31, 2019

Property, Plant and Equipment [Abstract]

Property, Plant, and Equipment

PROPERTY, PLANT, AND EQUIPMENT

The following is a summary of Property, plant, and equipment by classification as of December 31:

	2019			2018
Property, plant, and equipment	(In millions)
DTE Electric
Generation	$	12,028		$	11,027
Distribution	9,715			9,153
Other	2,536			2,567
Total DTE Electric	24,279			22,747
DTE Gas
Distribution	4,164			3,823
Storage	570			548
Transmission and other	1,244			1,204
Total DTE Gas	5,978			5,575
Non-utility and other
Gas Storage and Pipelines	3,524			2,307
Power and Industrial Projects	1,108			1,070
Other	183			111
Non-utility and other	4,815			3,488
Total DTE Energy	35,072			31,810
Accumulated depreciation and amortization
DTE Electric
Generation	(3,460		)	(3,609		)
Distribution	(2,553		)	(2,974		)
Other	(693		)	(727		)
Total DTE Electric	(6,706		)	(7,310		)
DTE Gas
Distribution	(1,334		)	(1,283		)
Storage	(172		)	(165		)
Transmission and other	(409		)	(404		)
Total DTE Gas	(1,915		)	(1,852		)
Non-utility and other
Gas Storage and Pipelines	(459		)	(390		)
Power and Industrial Projects	(604		)	(546		)
Other	(71		)	(62		)
Non-utility and other	(1,134		)	(998		)
Total DTE Energy	(9,755		)	(10,160		)
Net DTE Energy Property, plant, and equipment	$	25,317		$	21,650
Net DTE Electric Property, plant, and equipment	$	17,573		$	15,437

The following is a summary of the Registrants' AFUDC and interest capitalized for the years ended December 31:

	DTE Energy				DTE Electric
	2019		2018		2019		2018
	(In millions)
Allowance for debt funds used during construction and interest capitalized	$	15	$	15	$	10	$	9
Allowance for equity funds used during construction	24		28		22		19
Total	$	39	$	43	$	32	$	28

The composite depreciation rate for DTE Electric was approximately 4.0%, 3.7%, and 3.6% in 2019, 2018 and 2017, respectively. The composite depreciation rate for DTE Gas was 2.7% for all periods. The average estimated useful life for each major class of utility Property, plant, and equipment as of December 31, 2019 follows:

	Estimated Useful Lives in Years
Utility	Generation	Distribution	Storage
DTE Electric	34	38	N/A
DTE Gas	N/A	50	56

The estimated useful lives for DTE Electric's Other utility assets range from 3 to 80 years, while the estimated useful lives for DTE Gas' Transmission and other utility assets range from 3 to 70 years. The estimated useful lives for major classes of DTE Energy's non-utility assets and facilities range from 2 to 55 years.

The following is a summary of Depreciation and amortization expense for DTE Energy:

	2019		2018		2017
	(In millions)
Property, plant, and equipment	$	997	$	878	$	829
Regulatory assets and liabilities	227		212		165
Intangible assets	33		27		29
Other	6		7		7
	$	1,263	$	1,124	$	1,030

The following is a summary of Depreciation and amortization expense for DTE Electric:

	2019		2018		2017
	(In millions)
Property, plant, and equipment	$	748	$	652	$	615
Regulatory assets and liabilities	193		179		133
Other	5		5		5
	$	946	$	836	$	753

Capitalized software costs are classified as Property, plant, and equipment and the related amortization is included in accumulated depreciation and amortization on the Registrants' Consolidated Financial Statements. The Registrants capitalize the costs associated with computer software developed or obtained for use in their businesses. The Registrants amortize capitalized software costs on a straight-line basis over the expected period of benefit, ranging from 3 to 15 years for DTE Energy and 3 to 15 years for DTE Electric.

The following balances for capitalized software relate to DTE Energy:

	Year Ended December 31,
	2019		2018		2017
	(In millions)
Amortization expense of capitalized software	$	123	$	108	$	101
Gross carrying value of capitalized software	$	906	$	905
Accumulated amortization of capitalized software	$	520	$	534

The following balances for capitalized software relate to DTE Electric:

	Year Ended December 31,
	2019		2018		2017
	(In millions)
Amortization expense of capitalized software	$	112	$	101	$	93
Gross carrying value of capitalized software	$	811	$	799
Accumulated amortization of capitalized software	$	462	$	463