Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2018

Public Utilities, General Disclosures [Line Items]

Schedule of Regulatory Assets

The following tables present the regulatory assets and liabilities recorded on the Consolidated Balance Sheets of Duke Energy and Progress Energy. See separate tables below for balances by individual registrant.

	Duke Energy				Progress Energy
	December 31,				December 31,
(in millions)	2018		2017		2018		2017
Regulatory Assets
AROs – coal ash	$	4,255	$	4,025	$	2,061	$	1,984
AROs – nuclear and other	772		852		601		655
Accrued pension and OPEB	2,654		2,249		1,074		906
Retired generation facilities	445		480		367		386
Debt fair value adjustment	1,099		1,197		—		—
Deferred asset – Lee COLA	383		—		—		—
Storm cost deferrals	1,117		531		953		526
Nuclear asset securitized balance, net	1,093		1,142		1,093		1,142
Hedge costs deferrals	204		234		74		94
Derivatives – natural gas supply contracts	141		142		—		—
Demand side management (DSM)/Energy efficiency (EE)	449		530		256		281
Grid modernization	31		39		—		—
Vacation accrual	213		213		41		42
Deferred fuel and purchased power	838		507		600		349
Nuclear deferral	133		119		46		35
Post-in-service carrying costs (PISCC) and deferred operating expenses	320		366		36		38
Transmission expansion obligation	39		46		—		—
Manufactured gas plant (MGP)	99		91		—		—
Advanced metering infrastructure (AMI)	367		362		127		150
NCEMPA deferrals	50		53		50		53
East Bend deferrals	47		45		—		—
Deferred pipeline integrity costs	65		54		—		—
Amounts due from customers	24		64		—		—
Other	784		538		322		110
Total regulatory assets	15,622		13,879		7,701		6,751
Less: current portion	2,005		1,437		1,137		741
Total noncurrent regulatory assets	$	13,617	$	12,442	$	6,564	$	6,010
Regulatory Liabilities
Costs of removal	$	5,421	$	5,968	$	2,135	$	2,537
AROs – nuclear and other	538		806		—		—
Net regulatory liability related to income taxes	8,058		8,113		2,710		2,802
Amounts to be refunded to customers	34		10		—		—
Storm reserve	—		20		—		—
Accrued pension and OPEB	301		146		149		—
Deferred fuel and purchased power	16		47		16		1
Other	1,064		622		319		179
Total regulatory liabilities	15,432		15,732		5,329		5,519
Less: current portion	598		402		280		213
Total noncurrent regulatory liabilities	$	14,834	$	15,330	$	5,049	$	5,306

Schedule Of Regulatory Liabilities

The following tables present the regulatory assets and liabilities recorded on the Consolidated Balance Sheets of Duke Energy and Progress Energy. See separate tables below for balances by individual registrant.

	Duke Energy				Progress Energy
	December 31,				December 31,
(in millions)	2018		2017		2018		2017
Regulatory Assets
AROs – coal ash	$	4,255	$	4,025	$	2,061	$	1,984
AROs – nuclear and other	772		852		601		655
Accrued pension and OPEB	2,654		2,249		1,074		906
Retired generation facilities	445		480		367		386
Debt fair value adjustment	1,099		1,197		—		—
Deferred asset – Lee COLA	383		—		—		—
Storm cost deferrals	1,117		531		953		526
Nuclear asset securitized balance, net	1,093		1,142		1,093		1,142
Hedge costs deferrals	204		234		74		94
Derivatives – natural gas supply contracts	141		142		—		—
Demand side management (DSM)/Energy efficiency (EE)	449		530		256		281
Grid modernization	31		39		—		—
Vacation accrual	213		213		41		42
Deferred fuel and purchased power	838		507		600		349
Nuclear deferral	133		119		46		35
Post-in-service carrying costs (PISCC) and deferred operating expenses	320		366		36		38
Transmission expansion obligation	39		46		—		—
Manufactured gas plant (MGP)	99		91		—		—
Advanced metering infrastructure (AMI)	367		362		127		150
NCEMPA deferrals	50		53		50		53
East Bend deferrals	47		45		—		—
Deferred pipeline integrity costs	65		54		—		—
Amounts due from customers	24		64		—		—
Other	784		538		322		110
Total regulatory assets	15,622		13,879		7,701		6,751
Less: current portion	2,005		1,437		1,137		741
Total noncurrent regulatory assets	$	13,617	$	12,442	$	6,564	$	6,010
Regulatory Liabilities
Costs of removal	$	5,421	$	5,968	$	2,135	$	2,537
AROs – nuclear and other	538		806		—		—
Net regulatory liability related to income taxes	8,058		8,113		2,710		2,802
Amounts to be refunded to customers	34		10		—		—
Storm reserve	—		20		—		—
Accrued pension and OPEB	301		146		149		—
Deferred fuel and purchased power	16		47		16		1
Other	1,064		622		319		179
Total regulatory liabilities	15,432		15,732		5,329		5,519
Less: current portion	598		402		280		213
Total noncurrent regulatory liabilities	$	14,834	$	15,330	$	5,049	$	5,306

Schedule of Potential Plant Retirements

The table below contains the net carrying value of generating facilities planned for retirement or included in recent IRPs as evaluated for potential retirement due to a lack of requisite environmental control equipment. Dollar amounts in the table below are included in Net property, plant and equipment on the Consolidated Balance Sheets as of December 31, 2018, and exclude capitalized asset retirement costs.

		Remaining Net
	Capacity	Book Value
	(in MW)	(in millions)
Duke Energy Carolinas
Allen Steam Station Units 1-3(a)	585	$	162
Duke Energy Indiana
Gallagher Units 2 and 4(b)	280	121
Total Duke Energy	865	$	283

(a) Duke Energy Carolinas will retire Allen Steam Station Units 1 through 3 by December 31, 2024, as part of the resolution of a lawsuit involving alleged New Source Review violations.

(b) Duke Energy Indiana committed to either retire or stop burning coal at Gallagher Units 2 and 4 by December 31, 2022, as part of the 2016 settlement of Edwardsport IGCC matters.

Duke Energy Carolinas [Member]

Public Utilities, General Disclosures [Line Items]

Schedule of Regulatory Assets

The following tables present the regulatory assets and liabilities recorded on Duke Energy Carolinas' Consolidated Balance Sheets.

	December 31,				Earns/Pays	Recovery/Refund
(in millions)	2018		2017		a Return	Period Ends
Regulatory Assets(a)
AROs – coal ash	$	1,725	$	1,645	(i)	(b)
Accrued pension and OPEB	581		410			(j)
Retired generation facilities(c)	21		29		X	2023
Deferred Asset – Lee COLA	383		—			(b)
Storm cost deferrals	160		—		X	(b)
Hedge costs deferrals(c)	101		109		X	2041
DSM/EE	169		210		(h)	(h)
Vacation accrual	78		83		(e)	2019
Deferred fuel and purchased power	196		140		(f)	2020
Nuclear deferral	87		84			2020
PISCC(c)	34		35		X	(b)
AMI	176		185		X	(b)
Other	266		222			(b)
Total regulatory assets	3,977		3,152
Less: current portion	520		299
Total noncurrent regulatory assets	$	3,457	$	2,853
Regulatory Liabilities(a)
Costs of removal(c)	$	1,968	$	2,054	X	(g)
ARO – nuclear and other	538		806			(b)
Net regulatory liability related to income taxes(d)	3,082		3,028			(b)
Storm reserve(c)	—		20			(b)
Accrued pension and OPEB	38		44			(j)
Deferred fuel and purchased power	—		46		(f)	2020
Other	572		359			(b)
Total regulatory liabilities	6,198		6,357
Less: current portion	199		126
Total noncurrent regulatory liabilities	$	5,999	$	6,231

(a) Regulatory assets and liabilities are excluded from rate base unless otherwise noted.

(b) The expected recovery or refund period varies or has not been determined.

(c) Included in rate base.

(d) Includes regulatory liabilities related to the change in the federal tax rate as a result of the Tax Act and the change in the North Carolina tax rate, both discussed in Note 23.

(e) Earns a return on outstanding balance in North Carolina.

(f) Pays interest on over-recovered costs in North Carolina. Includes certain purchased power costs in North Carolina and South Carolina and costs of distributed energy in South Carolina.

(g) Recovered over the life of the associated assets.

(h) Includes incentives on DSM/EE investments and is recovered through an annual rider mechanism.

(i) Earns a debt and equity return on coal ash expenditures for North Carolina and South Carolina retail customers as permitted by various regulatory orders.

(j) Recovered primarily over the average remaining service periods or life expectancies of employees covered by the benefit plans. See Note 22 for additional detail.

Schedule Of Regulatory Liabilities

The following tables present the regulatory assets and liabilities recorded on Duke Energy Carolinas' Consolidated Balance Sheets.

	December 31,				Earns/Pays	Recovery/Refund
(in millions)	2018		2017		a Return	Period Ends
Regulatory Assets(a)
AROs – coal ash	$	1,725	$	1,645	(i)	(b)
Accrued pension and OPEB	581		410			(j)
Retired generation facilities(c)	21		29		X	2023
Deferred Asset – Lee COLA	383		—			(b)
Storm cost deferrals	160		—		X	(b)
Hedge costs deferrals(c)	101		109		X	2041
DSM/EE	169		210		(h)	(h)
Vacation accrual	78		83		(e)	2019
Deferred fuel and purchased power	196		140		(f)	2020
Nuclear deferral	87		84			2020
PISCC(c)	34		35		X	(b)
AMI	176		185		X	(b)
Other	266		222			(b)
Total regulatory assets	3,977		3,152
Less: current portion	520		299
Total noncurrent regulatory assets	$	3,457	$	2,853
Regulatory Liabilities(a)
Costs of removal(c)	$	1,968	$	2,054	X	(g)
ARO – nuclear and other	538		806			(b)
Net regulatory liability related to income taxes(d)	3,082		3,028			(b)
Storm reserve(c)	—		20			(b)
Accrued pension and OPEB	38		44			(j)
Deferred fuel and purchased power	—		46		(f)	2020
Other	572		359			(b)
Total regulatory liabilities	6,198		6,357
Less: current portion	199		126
Total noncurrent regulatory liabilities	$	5,999	$	6,231

(a) Regulatory assets and liabilities are excluded from rate base unless otherwise noted.

(b) The expected recovery or refund period varies or has not been determined.

(c) Included in rate base.

(d) Includes regulatory liabilities related to the change in the federal tax rate as a result of the Tax Act and the change in the North Carolina tax rate, both discussed in Note 23.

(e) Earns a return on outstanding balance in North Carolina.

(f) Pays interest on over-recovered costs in North Carolina. Includes certain purchased power costs in North Carolina and South Carolina and costs of distributed energy in South Carolina.

(g) Recovered over the life of the associated assets.

(h) Includes incentives on DSM/EE investments and is recovered through an annual rider mechanism.

(i) Earns a debt and equity return on coal ash expenditures for North Carolina and South Carolina retail customers as permitted by various regulatory orders.

(j) Recovered primarily over the average remaining service periods or life expectancies of employees covered by the benefit plans. See Note 22 for additional detail.

Progress Energy [Member]

Public Utilities, General Disclosures [Line Items]

Schedule of Regulatory Assets

The following tables present the regulatory assets and liabilities recorded on the Consolidated Balance Sheets of Duke Energy and Progress Energy. See separate tables below for balances by individual registrant.

	Duke Energy				Progress Energy
	December 31,				December 31,
(in millions)	2018		2017		2018		2017
Regulatory Assets
AROs – coal ash	$	4,255	$	4,025	$	2,061	$	1,984
AROs – nuclear and other	772		852		601		655
Accrued pension and OPEB	2,654		2,249		1,074		906
Retired generation facilities	445		480		367		386
Debt fair value adjustment	1,099		1,197		—		—
Deferred asset – Lee COLA	383		—		—		—
Storm cost deferrals	1,117		531		953		526
Nuclear asset securitized balance, net	1,093		1,142		1,093		1,142
Hedge costs deferrals	204		234		74		94
Derivatives – natural gas supply contracts	141		142		—		—
Demand side management (DSM)/Energy efficiency (EE)	449		530		256		281
Grid modernization	31		39		—		—
Vacation accrual	213		213		41		42
Deferred fuel and purchased power	838		507		600		349
Nuclear deferral	133		119		46		35
Post-in-service carrying costs (PISCC) and deferred operating expenses	320		366		36		38
Transmission expansion obligation	39		46		—		—
Manufactured gas plant (MGP)	99		91		—		—
Advanced metering infrastructure (AMI)	367		362		127		150
NCEMPA deferrals	50		53		50		53
East Bend deferrals	47		45		—		—
Deferred pipeline integrity costs	65		54		—		—
Amounts due from customers	24		64		—		—
Other	784		538		322		110
Total regulatory assets	15,622		13,879		7,701		6,751
Less: current portion	2,005		1,437		1,137		741
Total noncurrent regulatory assets	$	13,617	$	12,442	$	6,564	$	6,010
Regulatory Liabilities
Costs of removal	$	5,421	$	5,968	$	2,135	$	2,537
AROs – nuclear and other	538		806		—		—
Net regulatory liability related to income taxes	8,058		8,113		2,710		2,802
Amounts to be refunded to customers	34		10		—		—
Storm reserve	—		20		—		—
Accrued pension and OPEB	301		146		149		—
Deferred fuel and purchased power	16		47		16		1
Other	1,064		622		319		179
Total regulatory liabilities	15,432		15,732		5,329		5,519
Less: current portion	598		402		280		213
Total noncurrent regulatory liabilities	$	14,834	$	15,330	$	5,049	$	5,306

Schedule Of Regulatory Liabilities

The following tables present the regulatory assets and liabilities recorded on the Consolidated Balance Sheets of Duke Energy and Progress Energy. See separate tables below for balances by individual registrant.

	Duke Energy				Progress Energy
	December 31,				December 31,
(in millions)	2018		2017		2018		2017
Regulatory Assets
AROs – coal ash	$	4,255	$	4,025	$	2,061	$	1,984
AROs – nuclear and other	772		852		601		655
Accrued pension and OPEB	2,654		2,249		1,074		906
Retired generation facilities	445		480		367		386
Debt fair value adjustment	1,099		1,197		—		—
Deferred asset – Lee COLA	383		—		—		—
Storm cost deferrals	1,117		531		953		526
Nuclear asset securitized balance, net	1,093		1,142		1,093		1,142
Hedge costs deferrals	204		234		74		94
Derivatives – natural gas supply contracts	141		142		—		—
Demand side management (DSM)/Energy efficiency (EE)	449		530		256		281
Grid modernization	31		39		—		—
Vacation accrual	213		213		41		42
Deferred fuel and purchased power	838		507		600		349
Nuclear deferral	133		119		46		35
Post-in-service carrying costs (PISCC) and deferred operating expenses	320		366		36		38
Transmission expansion obligation	39		46		—		—
Manufactured gas plant (MGP)	99		91		—		—
Advanced metering infrastructure (AMI)	367		362		127		150
NCEMPA deferrals	50		53		50		53
East Bend deferrals	47		45		—		—
Deferred pipeline integrity costs	65		54		—		—
Amounts due from customers	24		64		—		—
Other	784		538		322		110
Total regulatory assets	15,622		13,879		7,701		6,751
Less: current portion	2,005		1,437		1,137		741
Total noncurrent regulatory assets	$	13,617	$	12,442	$	6,564	$	6,010
Regulatory Liabilities
Costs of removal	$	5,421	$	5,968	$	2,135	$	2,537
AROs – nuclear and other	538		806		—		—
Net regulatory liability related to income taxes	8,058		8,113		2,710		2,802
Amounts to be refunded to customers	34		10		—		—
Storm reserve	—		20		—		—
Accrued pension and OPEB	301		146		149		—
Deferred fuel and purchased power	16		47		16		1
Other	1,064		622		319		179
Total regulatory liabilities	15,432		15,732		5,329		5,519
Less: current portion	598		402		280		213
Total noncurrent regulatory liabilities	$	14,834	$	15,330	$	5,049	$	5,306

Duke Energy Progress [Member]

Public Utilities, General Disclosures [Line Items]

Schedule of Regulatory Assets

The following tables present the regulatory assets and liabilities recorded on Duke Energy Progress' Consolidated Balance Sheets.

	December 31,				Earns/Pays	Recovery/Refund
(in millions)	2018		2017		a Return	Period Ends
Regulatory Assets(a)
AROs – coal ash	$	2,051	$	1,975	(h)	(b)
AROs – nuclear and other	429		359			(c)
Accrued pension and OPEB	542		430			(k)
Retired generation facilities	148		170		X	(b)
Storm cost deferrals(d)	571		150		X	(b)
Hedge costs deferrals	54		64			(b)
DSM/EE(e)	235		264		(i)	(i)
Vacation accrual	41		42			2019
Deferred fuel and purchased power	397		130		(f)	2020
Nuclear deferral	46		35			2020
PISCC and deferred operating expenses	36		38		X	2054
AMI	67		75			(b)
NCEMPA deferrals	50		53		(g)	2042
Other	147		74			(b)
Total regulatory assets	4,814		3,859
Less: current portion	703		352
Total noncurrent regulatory assets	$	4,111	$	3,507
Regulatory Liabilities(a)
Costs of removal	$	1,878	$	2,122	X	(j)
Accrued pension and OPEB	93		—			(k)
Net regulatory liability related to income taxes(l)	1,863		1,854			(b)
Deferred fuel and purchased power	—		1		(f)	2020
Other	299		161			(b)
Total regulatory liabilities	4,133		4,138
Less: current portion	178		139
Total noncurrent regulatory liabilities	$	3,955	$	3,999

(a) Regulatory assets and liabilities are excluded from rate base unless otherwise noted.

(b) The expected recovery or refund period varies or has not been determined.

(c) Recovery period for costs related to nuclear facilities runs through the decommissioning period of each unit.

(d) South Carolina storm costs are included in rate base.

(e) Included in rate base.

(f) Pays interest on over-recovered costs in North Carolina. Includes certain purchased power costs in North Carolina and South Carolina and costs of distributed energy in South Carolina.

(g) South Carolina retail allocated costs are earning a return.

(h) Earns a debt and equity return on coal ash expenditures for North Carolina and South Carolina retail customers as permitted by various regulatory orders.

(i) Includes incentives on DSM/EE investments and is recovered through an annual rider mechanism.

(j) Recovered over the life of the associated assets.

(k) Recovered primarily over the average remaining service periods or life expectancies of employees covered by the benefit plans. See Note 22 for additional detail.

(l) Includes regulatory liabilities related to the change in the federal tax rate as a result of the Tax Act and the change in the North Carolina tax rate, both discussed in Note 23.

Schedule Of Regulatory Liabilities

The following tables present the regulatory assets and liabilities recorded on Duke Energy Progress' Consolidated Balance Sheets.

	December 31,				Earns/Pays	Recovery/Refund
(in millions)	2018		2017		a Return	Period Ends
Regulatory Assets(a)
AROs – coal ash	$	2,051	$	1,975	(h)	(b)
AROs – nuclear and other	429		359			(c)
Accrued pension and OPEB	542		430			(k)
Retired generation facilities	148		170		X	(b)
Storm cost deferrals(d)	571		150		X	(b)
Hedge costs deferrals	54		64			(b)
DSM/EE(e)	235		264		(i)	(i)
Vacation accrual	41		42			2019
Deferred fuel and purchased power	397		130		(f)	2020
Nuclear deferral	46		35			2020
PISCC and deferred operating expenses	36		38		X	2054
AMI	67		75			(b)
NCEMPA deferrals	50		53		(g)	2042
Other	147		74			(b)
Total regulatory assets	4,814		3,859
Less: current portion	703		352
Total noncurrent regulatory assets	$	4,111	$	3,507
Regulatory Liabilities(a)
Costs of removal	$	1,878	$	2,122	X	(j)
Accrued pension and OPEB	93		—			(k)
Net regulatory liability related to income taxes(l)	1,863		1,854			(b)
Deferred fuel and purchased power	—		1		(f)	2020
Other	299		161			(b)
Total regulatory liabilities	4,133		4,138
Less: current portion	178		139
Total noncurrent regulatory liabilities	$	3,955	$	3,999

(a) Regulatory assets and liabilities are excluded from rate base unless otherwise noted.

(b) The expected recovery or refund period varies or has not been determined.

(c) Recovery period for costs related to nuclear facilities runs through the decommissioning period of each unit.

(d) South Carolina storm costs are included in rate base.

(e) Included in rate base.

(f) Pays interest on over-recovered costs in North Carolina. Includes certain purchased power costs in North Carolina and South Carolina and costs of distributed energy in South Carolina.

(g) South Carolina retail allocated costs are earning a return.

(h) Earns a debt and equity return on coal ash expenditures for North Carolina and South Carolina retail customers as permitted by various regulatory orders.

(i) Includes incentives on DSM/EE investments and is recovered through an annual rider mechanism.

(j) Recovered over the life of the associated assets.

(k) Recovered primarily over the average remaining service periods or life expectancies of employees covered by the benefit plans. See Note 22 for additional detail.

(l) Includes regulatory liabilities related to the change in the federal tax rate as a result of the Tax Act and the change in the North Carolina tax rate, both discussed in Note 23.

Duke Energy Florida [Member]

Public Utilities, General Disclosures [Line Items]

Schedule of Regulatory Assets

The following tables present the regulatory assets and liabilities recorded on Duke Energy Florida's Consolidated Balance Sheets.

	December 31,				Earns/Pays	Recovery/Refund
(in millions)	2018		2017		a Return	Period Ends
Regulatory Assets(a)
AROs – coal ash(c)	$	10	$	9		(b)
AROs – nuclear and other(c)	172		296			(b)
Accrued pension and OPEB(c)	532		476		X	(g)
Retired generation facilities(c)	219		216		X	(b)
Storm cost deferrals(c)(h)	382		376		(e)	2021
Nuclear asset securitized balance, net	1,093		1,142			2036
Hedge costs deferrals	20		30			2020
DSM/EE(c)	21		17		X	2023
Deferred fuel and purchased power(c)	203		219		(f)	2020
AMI(c)	60		75		X	2032
Other	176		36		(d)	(b)
Total regulatory assets	2,888		2,892
Less: current portion	434		389
Total noncurrent regulatory assets	$	2,454	$	2,503
Regulatory Liabilities(a)
Costs of removal(c)	$	257	$	415	(d)	(b)
Net regulatory liability related to income taxes(c)	847		948			(b)
Accrued pension and OPEB	56		—		X	(g)
Deferred fuel and purchased power(c)	16		—		(f)	2020
Other	20		18		(d)	(b)
Total regulatory liabilities	1,196		1,381
Less: current portion	102		74
Total noncurrent regulatory liabilities	$	1,094	$	1,307

(a) Regulatory assets and liabilities are excluded from rate base unless otherwise noted.

(b) The expected recovery or refund period varies or has not been determined.

(c) Included in rate base.

(d) Certain costs earn a return.

(e) Earns a debt return/interest once collections begin.

(f) Earns commercial paper rate.

(g) Recovered primarily over the average remaining service periods or life expectancies of employees covered by the benefit plans. See Note 22 for additional detail.

(h) Balance includes $165 million for Hurricane Michael. Duke Energy Florida expects to seek recovery of these costs in the first half of 2019.

Schedule Of Regulatory Liabilities

The following tables present the regulatory assets and liabilities recorded on Duke Energy Florida's Consolidated Balance Sheets.

	December 31,				Earns/Pays	Recovery/Refund
(in millions)	2018		2017		a Return	Period Ends
Regulatory Assets(a)
AROs – coal ash(c)	$	10	$	9		(b)
AROs – nuclear and other(c)	172		296			(b)
Accrued pension and OPEB(c)	532		476		X	(g)
Retired generation facilities(c)	219		216		X	(b)
Storm cost deferrals(c)(h)	382		376		(e)	2021
Nuclear asset securitized balance, net	1,093		1,142			2036
Hedge costs deferrals	20		30			2020
DSM/EE(c)	21		17		X	2023
Deferred fuel and purchased power(c)	203		219		(f)	2020
AMI(c)	60		75		X	2032
Other	176		36		(d)	(b)
Total regulatory assets	2,888		2,892
Less: current portion	434		389
Total noncurrent regulatory assets	$	2,454	$	2,503
Regulatory Liabilities(a)
Costs of removal(c)	$	257	$	415	(d)	(b)
Net regulatory liability related to income taxes(c)	847		948			(b)
Accrued pension and OPEB	56		—		X	(g)
Deferred fuel and purchased power(c)	16		—		(f)	2020
Other	20		18		(d)	(b)
Total regulatory liabilities	1,196		1,381
Less: current portion	102		74
Total noncurrent regulatory liabilities	$	1,094	$	1,307

(a) Regulatory assets and liabilities are excluded from rate base unless otherwise noted.

(b) The expected recovery or refund period varies or has not been determined.

(c) Included in rate base.

(d) Certain costs earn a return.

(e) Earns a debt return/interest once collections begin.

(f) Earns commercial paper rate.

(g) Recovered primarily over the average remaining service periods or life expectancies of employees covered by the benefit plans. See Note 22 for additional detail.

(h) Balance includes $165 million for Hurricane Michael. Duke Energy Florida expects to seek recovery of these costs in the first half of 2019.

Duke Energy Ohio [Member]

Public Utilities, General Disclosures [Line Items]

Schedule of Regulatory Assets

The following tables present the regulatory assets and liabilities recorded on Duke Energy Ohio's Consolidated Balance Sheets.

	December 31,				Earns/Pays	Recovery/Refund
(in millions)	2018		2017		a Return	Period Ends
Regulatory Assets(a)
AROs – coal ash	$	20	$	17	X	(b)
Accrued pension and OPEB	146		139			(g)
Storm cost deferrals	4		5			2023
Hedge costs deferrals	5		6			(b)
DSM/EE	10		18		(f)	(e)
Grid modernization	31		39		X	(e)
Vacation accrual	5		5			2019
Deferred fuel and purchased power	2		—			2019
PISCC and deferred operating expenses(c)	17		19		X	2083
Transmission expansion obligation	43		50			(e)
MGP	99		91			(b)
AMI	46		6			(b)
East Bend deferrals	47		45		X	(b)
Deferred pipeline integrity costs	14		12		X	(b)
Other	75		42			(b)
Total regulatory assets	564		494
Less: current portion	33		49
Total noncurrent regulatory assets	$	531	$	445
Regulatory Liabilities(a)
Costs of removal	$	126	$	189		(d)
Net regulatory liability related to income taxes	678		688			(b)
Accrued pension and OPEB	18		16			(g)
Other	75		34			(b)
Total regulatory liabilities	897		927
Less: current portion	57		36
Total noncurrent regulatory liabilities	$	840	$	891

(a) Regulatory assets and liabilities are excluded from rate base unless otherwise noted.

(b) The expected recovery or refund period varies or has not been determined.

(c) Included in rate base.

(d) Recovery over the life of the associated assets.

(e) Recovered via a rider mechanism.

(f) Includes incentives on DSM/EE investments.

(g) Recovered primarily over the average remaining service periods or life expectancies of employees covered by the benefit plans. See Note 22 for additional detail.

Schedule Of Regulatory Liabilities

The following tables present the regulatory assets and liabilities recorded on Duke Energy Ohio's Consolidated Balance Sheets.

	December 31,				Earns/Pays	Recovery/Refund
(in millions)	2018		2017		a Return	Period Ends
Regulatory Assets(a)
AROs – coal ash	$	20	$	17	X	(b)
Accrued pension and OPEB	146		139			(g)
Storm cost deferrals	4		5			2023
Hedge costs deferrals	5		6			(b)
DSM/EE	10		18		(f)	(e)
Grid modernization	31		39		X	(e)
Vacation accrual	5		5			2019
Deferred fuel and purchased power	2		—			2019
PISCC and deferred operating expenses(c)	17		19		X	2083
Transmission expansion obligation	43		50			(e)
MGP	99		91			(b)
AMI	46		6			(b)
East Bend deferrals	47		45		X	(b)
Deferred pipeline integrity costs	14		12		X	(b)
Other	75		42			(b)
Total regulatory assets	564		494
Less: current portion	33		49
Total noncurrent regulatory assets	$	531	$	445
Regulatory Liabilities(a)
Costs of removal	$	126	$	189		(d)
Net regulatory liability related to income taxes	678		688			(b)
Accrued pension and OPEB	18		16			(g)
Other	75		34			(b)
Total regulatory liabilities	897		927
Less: current portion	57		36
Total noncurrent regulatory liabilities	$	840	$	891

(a) Regulatory assets and liabilities are excluded from rate base unless otherwise noted.

(b) The expected recovery or refund period varies or has not been determined.

(c) Included in rate base.

(d) Recovery over the life of the associated assets.

(e) Recovered via a rider mechanism.

(f) Includes incentives on DSM/EE investments.

(g) Recovered primarily over the average remaining service periods or life expectancies of employees covered by the benefit plans. See Note 22 for additional detail.

Schedule of MISO Exit Fee Obligations

The following table provides a reconciliation of the beginning and ending balance of Duke Energy Ohio’s recorded liability for its exit obligation and share of MTEP costs recorded in Other within Current Liabilities and Other Noncurrent Liabilities on the Consolidated Balance Sheets. The retail portions of MTEP costs billed by MISO are recovered by Duke Energy Ohio through a non-bypassable rider. As of December 31, 2018, and 2017, $43 million and $50 million, respectively, are recorded in Regulatory assets on Duke Energy Ohio's Consolidated Balance Sheets.

			Provisions/			Cash
(in millions)	December 31, 2017		Adjustments			Reductions			December 31, 2018
Duke Energy Ohio	$	66	$	(4	)	$	(4	)	$	58

Duke Energy Indiana [Member]

Public Utilities, General Disclosures [Line Items]

Schedule of Regulatory Assets

The following tables present the regulatory assets and liabilities recorded on Duke Energy Indiana's Consolidated Balance Sheets.

	December 31,				Earns/Pays	Recovery/Refund
(in millions)	2018		2017		a Return	Period Ends
Regulatory Assets(a)
AROs – coal ash	$	450	$	380		(b)
Accrued pension and OPEB	222		197			(f)
Retired generation facilities(c)	57		65		X	2026
Hedge costs deferrals	24		25			(b)
DSM/EE	14		21		(e)	(e)
Vacation accrual	11		11			2019
Deferred fuel and purchased power	40		18			2019
PISCC and deferred operating expenses(c)	233		274		X	(b)
AMI(c)	18		21		X	(b)
Other	88		131			(b)
Total regulatory assets	1,157		1,143
Less: current portion	175		165
Total noncurrent regulatory assets	$	982	$	978
Regulatory Liabilities(a)
Costs of removal	$	628	$	644		(d)
Net regulatory liability related to income taxes	1,009		998			(b)
Amounts to be refunded to customers	1		10			2019
Accrued pension and OPEB	67		64			(f)
Other	42		31			(b)
Total regulatory liabilities	1,747		1,747
Less: current portion	25		24
Total noncurrent regulatory liabilities	$	1,722	$	1,723

(a) Regulatory assets and liabilities are excluded from rate base unless otherwise noted.

(b) The expected recovery or refund period varies or has not been determined.

(c) Included in rate base.

(d) Recovery over the life of the associated assets.

(e) Includes incentives on DSM/EE investments and is recovered through a tracker mechanism over a two-year period.

(f) Recovered primarily over the average remaining service periods or life expectancies of employees covered by the benefit plans. See Note 22 for additional detail.

Schedule Of Regulatory Liabilities

The following tables present the regulatory assets and liabilities recorded on Duke Energy Indiana's Consolidated Balance Sheets.

	December 31,				Earns/Pays	Recovery/Refund
(in millions)	2018		2017		a Return	Period Ends
Regulatory Assets(a)
AROs – coal ash	$	450	$	380		(b)
Accrued pension and OPEB	222		197			(f)
Retired generation facilities(c)	57		65		X	2026
Hedge costs deferrals	24		25			(b)
DSM/EE	14		21		(e)	(e)
Vacation accrual	11		11			2019
Deferred fuel and purchased power	40		18			2019
PISCC and deferred operating expenses(c)	233		274		X	(b)
AMI(c)	18		21		X	(b)
Other	88		131			(b)
Total regulatory assets	1,157		1,143
Less: current portion	175		165
Total noncurrent regulatory assets	$	982	$	978
Regulatory Liabilities(a)
Costs of removal	$	628	$	644		(d)
Net regulatory liability related to income taxes	1,009		998			(b)
Amounts to be refunded to customers	1		10			2019
Accrued pension and OPEB	67		64			(f)
Other	42		31			(b)
Total regulatory liabilities	1,747		1,747
Less: current portion	25		24
Total noncurrent regulatory liabilities	$	1,722	$	1,723

(a) Regulatory assets and liabilities are excluded from rate base unless otherwise noted.

(b) The expected recovery or refund period varies or has not been determined.

(c) Included in rate base.

(d) Recovery over the life of the associated assets.

(e) Includes incentives on DSM/EE investments and is recovered through a tracker mechanism over a two-year period.

(f) Recovered primarily over the average remaining service periods or life expectancies of employees covered by the benefit plans. See Note 22 for additional detail.

Piedmont Natural Gas [Member]

Public Utilities, General Disclosures [Line Items]

Schedule of Regulatory Assets

The following tables present the regulatory assets and liabilities recorded on Piedmont's Consolidated Balance Sheets.

	December 31,				Earns/Pays	Recovery/Refund
(in millions)	2018		2017		a Return	Period Ends
Regulatory Assets(a)
AROs – other	$	19	$	15		(d)
Accrued pension and OPEB(c)	99		91		X	(f)
Derivatives – gas supply contracts(e)	141		142
Vacation accrual	12		10
Deferred pipeline integrity costs(c)	51		42		X	(b)
Amount due from customers	24		64		X	(b)
Other	11		14			(b)
Total regulatory assets	357		378
Less: current portion	54		95
Total noncurrent regulatory assets	$	303	$	283
Regulatory Liabilities(a)
Costs of removal	$	564	$	544		(d)
Net regulatory liability related to income taxes	579		597			(b)
Accrued pension and OPEB(c)	1		—		X	(f)
Amount due to customers	33		—		X	(b)
Other	41		3			(b)
Total regulatory liabilities	1,218		1,144
Less: current portion	37		3
Total noncurrent regulatory liabilities	$	1,181	$	1,141

(a) Regulatory assets and liabilities are excluded from rate base unless otherwise noted.

(b) The expected recovery or refund period varies or has not been determined.

(c) Included in rate base.

(d) Recovery over the life of the associated assets.

(e) Balance will fluctuate with changes in the market. Current contracts extend into 2031.

(f) Recovered primarily over the average remaining service periods or life expectancies of employees covered by the benefit plans. See Note 22 for additional detail.

Schedule Of Regulatory Liabilities

The following tables present the regulatory assets and liabilities recorded on Piedmont's Consolidated Balance Sheets.

	December 31,				Earns/Pays	Recovery/Refund
(in millions)	2018		2017		a Return	Period Ends
Regulatory Assets(a)
AROs – other	$	19	$	15		(d)
Accrued pension and OPEB(c)	99		91		X	(f)
Derivatives – gas supply contracts(e)	141		142
Vacation accrual	12		10
Deferred pipeline integrity costs(c)	51		42		X	(b)
Amount due from customers	24		64		X	(b)
Other	11		14			(b)
Total regulatory assets	357		378
Less: current portion	54		95
Total noncurrent regulatory assets	$	303	$	283
Regulatory Liabilities(a)
Costs of removal	$	564	$	544		(d)
Net regulatory liability related to income taxes	579		597			(b)
Accrued pension and OPEB(c)	1		—		X	(f)
Amount due to customers	33		—		X	(b)
Other	41		3			(b)
Total regulatory liabilities	1,218		1,144
Less: current portion	37		3
Total noncurrent regulatory liabilities	$	1,181	$	1,141

(a) Regulatory assets and liabilities are excluded from rate base unless otherwise noted.

(b) The expected recovery or refund period varies or has not been determined.

(c) Included in rate base.

(d) Recovery over the life of the associated assets.

(e) Balance will fluctuate with changes in the market. Current contracts extend into 2031.

(f) Recovered primarily over the average remaining service periods or life expectancies of employees covered by the benefit plans. See Note 22 for additional detail.