Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Line Items]

Summary of Property, Plant, and Equipment

The following is a summary of DPL’s Property, plant and equipment with corresponding composite depreciation rates at December 31, 2016 and 2015:

	December 31,
$ in millions	2016		Composite Rate	2015		Composite Rate
Regulated:
Transmission	$	247.3	3.9%	$	239.4	3.9%
Distribution	1,141.1		4.7%	1,085.7		5.0%
General	13.7		7.4%	13.9		7.2%
Non-depreciable	63.5		N/A	62.5		N/A
Total regulated	1,465.6			1,401.5
Unregulated:
Production / Generation	483.2		11.7%	1,413.1		4.2%
Other	17.0		8.0%	16.3		12.1%
Non-depreciable	19.8		N/A	19.8		N/A
Total unregulated	520.0			1,449.2
Total property, plant and equipment in service	$	1,985.6	6.1%	$	2,850.7	4.4%

Ownership Interests

DP&L’s undivided ownership interest in such facilities at December 31, 2016, is as follows:

	DP&L Share		DPL Carrying Value
	Ownership (%)	Summer Production Capacity (MW)	Gross Plant In Service ($ in millions)		Accumulated Depreciation ($ in millions)		Construction Work in Process ($ in millions)
Jointly-owned production units
Conesville - Unit 4	16.5	129	$	—	$	—	$	—
Killen - Unit 2	67.0	402	34		—		2
Miami Fort - Units 7 and 8	36.0	368	27		—		7
Stuart - Units 1 through 4	35.0	808	24		—		23
Zimmer - Unit 1	28.1	371	7		—		9
Transmission (at varying percentages)			43		10		—
Total		2,078	$	135	$	10	$	41

Changes in the Liability for Generation AROs

Changes in the Liability for Generation AROs

$ in millions
Balance at December 31, 2014	$	26.9
Calendar 2015
Additions	40.3
Accretion expense	1.9
Settlements	(3.2		)
Balance at December 31, 2015	65.9
Calendar 2016
Additions	70.2
Accretion expense	2.7
Settlements	—
Balance at December 31, 2016	$	138.8

Changes in the Liability for Transmission and Distribution Asset Removal Costs

Changes in the Liability for Transmission and Distribution Asset Removal Costs

$ in millions
Balance at December 31, 2014	$	119.3
Calendar 2015
Additions	24.3
Settlements	(21.8		)
Balance at December 31, 2015	121.8
Calendar 2016
Additions	11.7
Settlements	(7.0		)
Balance at December 31, 2016	$	126.5

THE DAYTON POWER AND LIGHT COMPANY [Member]

Property, Plant and Equipment [Line Items]

Summary of Property, Plant, and Equipment

The following is a summary of DP&L’s Property, plant and equipment with corresponding composite depreciation rates at December 31, 2016 and 2015:

	December 31,
$ in millions	2016		Composite Rate	2015		Composite Rate
Regulated:
Transmission	$	421.1	2.3%	$	413.7	2.3%
Distribution	1,693.5		3.2%	1,639.7		3.3%
General	31.6		3.2%	31.6		3.2%
Non-depreciable	63.5		N/A	62.5		N/A
Total regulated	2,209.7			2,147.5
Unregulated:
Production / Generation	173.9		26.2%	3,009.8		2.1%
Non-depreciable	15.0		N/A	15.0		N/A
Total unregulated	188.9			3,024.8
Total property, plant and equipment in service	$	2,398.6	4.6%	$	5,172.3	2.5%

Ownership Interests

DP&L’s undivided ownership interest in such facilities at December 31, 2016, is as follows:

	DP&L Share		DP&L Carrying Value
	Ownership %	Summer Production Capacity (MW)	Gross Plant In Service ($ in millions)		Accumulated Depreciation ($ in millions)		Construction Work in Process ($ in millions)
Jointly-owned production units
Conesville - Unit 4	16.5	129	$	—	$	—	$	—
Killen - Unit 2	67.0	402	34		—		2
Miami Fort - Units 7 and 8	36.0	368	27		—		7
Stuart - Units 1 through 4	35.0	808	24		—		23
Zimmer - Unit 1	28.1	371	7		—		9
Transmission (at varying percentages)			99		66		—
Total		2,078	$	191	$	66	$	41

Changes in the Liability for Generation AROs

Changes in the Liability for Generation AROs

$ in millions
Balance at December 31, 2014	$	22.9
Calendar 2015
Additions	40.3
Accretion expense	2.1
Settlements	(3.2		)
Balance at December 31, 2015	62.1
Calendar 2016
Additions	70.2
Accretion expense	2.9
Settlements	—
Balance at December 31, 2016	$	135.2

Changes in the Liability for Transmission and Distribution Asset Removal Costs

Changes in the Liability for Transmission and Distribution Asset Removal Costs

$ in millions
Balance at December 31, 2014	$	119.3
Calendar 2015
Additions	24.3
Settlements	(21.8		)
Balance at December 31, 2015	121.8
Calendar 2016
Additions	11.7
Settlements	(7.0		)
Balance at December 31, 2016	$	126.5