DOMINION ENERGY SOUTH CAROLINA, INC., 10-Q filed on 8/6/2021
Quarterly Report
v3.21.2
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2021
Jul. 30, 2021
Cover [Abstract]    
Entity Registrant Name DOMINION ENERGY SOUTH CAROLINA, INC.  
Entity Central Index Key 0000091882  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Document Type 10-Q  
Document Fiscal Year Focus 2021  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Entity Emerging Growth Company false  
Entity Small Business false  
Entity Common Stock, Shares Outstanding   40,296,147
Entity Current Reporting Status Yes  
Entity Shell Company false  
Entity File Number 001-3375  
Entity Tax Identification Number 57-0248695  
Entity Address, Address Line One 400 OTARRE PARKWAY  
Entity Address, City or Town CAYCE  
Entity Address, State or Province SC  
Entity Address, Postal Zip Code 29033  
City Area Code 803  
Local Phone Number 217-9000  
Entity Incorporation, State or Country Code SC  
Document Quarterly Report true  
Document Transition Report false  
Entity Interactive Data Current Yes  
Document Period End Date Jun. 30, 2021  
v3.21.2
Consolidated Balance Sheets (Unaudited) - USD ($)
$ in Millions
Jun. 30, 2021
Dec. 31, 2020
ASSETS    
Utility plant in service $ 13,939 $ 13,680
Accumulated depreciation and amortization (5,124) (5,027)
Construction work in progress 479 460
Nuclear fuel, net of accumulated amortization 217 221
Utility plant, net ($727 and $730 related to VIEs) 9,511 9,334
Nonutility Property and Investments:    
Nonutility property, net of accumulated depreciation 37 39
Assets held in trust, nuclear decommissioning 247 238
Nonutility property and investments, net 284 277
Current Assets:    
Cash and cash equivalents 22 5
Customer, net of allowance for uncollectible accounts of $4 and $10 324 365
Receivables, affiliated and related party 3 16
Receivables, other 76 64
Inventories (at average cost):    
Fuel 73 68
Gas stored 14 14
Materials and supplies 175 176
Prepayments 107 75
Regulatory assets 212 229
Other current assets 26 27
Total current assets ($95 and $103 related to VIEs) 1,032 1,039
Deferred Debits and Other Assets:    
Regulatory assets 3,460 3,726
Other 123 103
Total deferred debits and other assets ($36 and $35 related to VIEs) 3,583 3,829
Total assets 14,410 14,479
CAPITALIZATION AND LIABILITIES    
Common Stock - no par value 4,017 4,017
Retained earnings 122 277
Accumulated other comprehensive income (loss) (2) (2)
Total common equity 4,137 4,292
Noncontrolling interest 171 192
Total equity 4,308 4,484
Long-term debt, net 3,327 3,327
Affiliated long-term debt 230 230
Finance leases 13 15
Total long-term debt 3,570 3,572
Total capitalization 7,878 8,056
Current Liabilities:    
Short-term borrowings 60 0
Securities due within one year 39 39
Accounts payable 183 178
Affiliated and related party payables 578 457
Customer deposits and customer prepayments 70 70
Taxes accrued 116 215
Interest accrued 97 95
Regulatory liabilities 285 283
Reserves for litigation and regulatory proceedings 278 208
Other 111 40
Total current liabilities 1,817 1,585
Deferred Credits and Other Liabilities:    
Deferred income taxes and investment tax credits 806 858
Asset retirement obligations 610 597
Pension and other postretirement benefits 175 172
Regulatory liabilities 2,901 3,005
Affiliated liabilities 0 13
Other 223 193
Total deferred credits and other liabilities 4,715 4,838
Commitments and Contingencies
Total capitalization and liabilities $ 14,410 $ 14,479
v3.21.2
Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($)
shares in Millions, $ in Millions
Jun. 30, 2021
Dec. 31, 2020
Utility plant, net $ 9,511 $ 9,334
Receivables, customer, allowance for uncollectible accounts 4 10
Total current assets 1,032 1,039
Total deferred debits and other assets $ 3,583 $ 3,829
Common stock, par value $ 0 $ 0
Common stock, shares outstanding 40.3 40.3
Variable Interest Entity, Primary Beneficiary [Member]    
Utility plant, net $ 727 $ 730
Total current assets 95 103
Total deferred debits and other assets $ 36 $ 35
v3.21.2
Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Income Statement [Abstract]        
Operating Revenue [1] $ 692 $ 624 $ 1,436 $ 1,296
Operating Expenses:        
Fuel used in electric generation [1] 120 95 252 199
Purchased power [1] 27 25 43 38
Gas purchased for resale [1] 50 34 131 91
Other operations and maintenance 117 93 216 183
Other operations and maintenance - affiliated suppliers 47 50 100 105
Impairment of assets and other charges 259 0 319 2
Depreciation and amortization 119 118 240 236
Other taxes [1] 62 65 127 127
Total operating expenses 801 480 1,428 981
Operating income (loss) (109) 144 8 315
Other income (expense), net (12) 2 (6) 5
Interest charges, net of allowance for borrowed funds used during construction of $1, $1, $2 and $3 [2] 54 58 109 116
Income (loss) before income tax expense (175) 88 (107) 204
Income tax expense (benefit) (49) 21 (36) 44
Net Income (Loss) and Other Comprehensive Income (Loss) (126) 67 (71) 160
Comprehensive Income (Loss) Attributable to Noncontrolling Interest 5 (2) 9 3
Comprehensive Income (Loss) Available to Common Shareholder $ (131) $ 69 $ (80) $ 157
[1] See Note 12 for amounts attributable to affiliates.
[2]

See Note 5 for amounts attributable to affiliates.
v3.21.2
Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (Parenthetical) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Income Statement [Abstract]        
Allowance for borrowed funds used during construction $ 1 $ 1 $ 2 $ 3
v3.21.2
Consolidated Statements of Cash Flows (Unaudited) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Operating Activities    
Net income (loss) $ (71) $ 160
Adjustments to reconcile net income (loss) to net cash provided by operating activities:    
Impairment of assets and other charges 319 2
Deferred income taxes, net (52) 61
Depreciation and amortization 240 236
Amortization of nuclear fuel 20 21
Other adjustments 6 15
Changes in certain assets and liabilities:    
Receivables 21 (31)
Receivables - affiliated and related party (2) 5
Inventories (4) (3)
Prepayments (38) (30)
Pension and other postretirement benefits 3 (3)
Regulatory assets (51) 3
Regulatory liabilities (108) (111)
Accounts payable 81 (35)
Accounts payable - affiliated and related party (66) 4
Taxes accrued (99) (97)
Interest accrued 2 3
Other assets and liabilities 78 (12)
Net cash provided by operating activities 279 188
Investing Activities    
Property additions and construction expenditures (415) (330)
Proceeds from investments and sales of assets 6 5
Purchase of investments (7) (5)
Purchase of investments - affiliated (1) (1)
Short-term investments - affiliated 15 9
Net cash used in investing activities (402) (322)
Financing Activities    
Dividend to parent (105) 0
Short-term borrowings, net 60 0
Short-term borrowings - affiliated, net 187 141
Other (2) (4)
Net cash provided by financing activities 140 137
Net increase in cash, restricted cash and equivalents 17 3
Cash, restricted cash and equivalents at beginning of period [1] 5 4
Cash, restricted cash and equivalents at end of period [1] 22 7
Significant noncash investing and financing activities:    
Accrued construction expenditures 27 41
Leases [2] $ 0 $ 2
[1] At June 30, 2021, June 30, 2020, December 31, 2020 and December 31, 2019 there were no restricted cash and equivalent balances.
[2] Includes $2 million of financing leases for the six months ended June 30, 2020.
v3.21.2
Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2020
Jun. 30, 2021
Dec. 31, 2020
Dec. 31, 2019
Statement Of Cash Flows [Abstract]        
Restricted cash and equivalents $ 0 $ 0 $ 0 $ 0
Financing leases $ 2      
v3.21.2
Consolidated Statements of Changes in Common Equity (Unaudited) - USD ($)
shares in Millions, $ in Millions
Total
Common Stock
Retained Earnings
AOCI
Noncontrolling Interest
Beginning balance at Dec. 31, 2019 $ 3,892 $ 3,695 $ 20 $ (3) $ 180
Beginning balance (in shares) at Dec. 31, 2019   40      
Total comprehensive income (loss) available (attributable) to common shareholder 160   157   3
Ending balance at Jun. 30, 2020 4,052 $ 3,695 177 (3) 183
Ending balance (in shares) at Jun. 30, 2020   40      
Beginning balance at Mar. 31, 2020 3,985 $ 3,695 108 (3) 185
Beginning balance (in shares) at Mar. 31, 2020   40      
Total comprehensive income (loss) available (attributable) to common shareholder 67   69   (2)
Ending balance at Jun. 30, 2020 4,052 $ 3,695 177 (3) 183
Ending balance (in shares) at Jun. 30, 2020   40      
Beginning balance at Dec. 31, 2020 4,484 $ 4,017 277 (2) 192
Beginning balance (in shares) at Dec. 31, 2020   40      
Total comprehensive income (loss) available (attributable) to common shareholder (71)   (80)   9
Dividend to parent (105)   (75)   (30)
Ending balance at Jun. 30, 2021 4,308 $ 4,017 122 (2) 171
Ending balance (in shares) at Jun. 30, 2021   40      
Beginning balance at Mar. 31, 2021 4,464 $ 4,017 253 (2) 196
Beginning balance (in shares) at Mar. 31, 2021   40      
Total comprehensive income (loss) available (attributable) to common shareholder (126)   (131)   5
Dividend to parent (30)       (30)
Ending balance at Jun. 30, 2021 $ 4,308 $ 4,017 $ 122 $ (2) $ 171
Ending balance (in shares) at Jun. 30, 2021   40      
v3.21.2
Summary of Significant Accounting Policies
 6 Months Ended
Jun. 30, 2021
Accounting Policies [Abstract]  
Summary of Significant Accounting Policies

1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Consolidation and Variable Interest Entities

DESC has determined that it has a controlling financial interest in each of GENCO and Fuel Company (which are considered to be VIEs) and, accordingly, DESC's Consolidated Financial Statements include, after eliminating intercompany balances and transactions, the accounts of DESC, GENCO and Fuel Company. See Note 2 to the Consolidated Financial Statements included in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020 for a description of GENCO and Fuel Company.

Effective January 2021, DESC purchases shared services from DES, an affiliated VIE that provides accounting, legal, finance and certain administrative and technical services to all Dominion Energy subsidiaries, including DESC. DESC had previously purchased such services from DESS, an affiliated VIE, that had provided such services to all SCANA subsidiaries. DESC has determined that it is not the primary beneficiary of DES as it does not have either the power to direct the activities that most significantly impact its economic performance or an obligation to absorb losses and benefits which could be significant to it. See Note 12 for amounts attributable to affiliates.

Significant Accounting Policies

There have been no significant changes from Note 2 to the Consolidated Financial Statements in DESC's Annual Report on Form 10-K for the year ended December 31, 2020.
v3.21.2
Rate and Other Regulatory Matters
 6 Months Ended
Jun. 30, 2021
Regulated Operations [Abstract]  
Rate and Other Regulatory Matters

2. RATE AND OTHER REGULATORY MATTERS

 

Regulatory Matters Involving Potential Loss Contingencies

As a result of issues generated in the ordinary course of business, DESC is involved in various regulatory matters. Certain regulatory matters may ultimately result in a loss; however, as such matters are in an initial procedural phase, involve uncertainty as to the outcome of pending reviews or orders, and/or involve significant factual issues that need to be resolved, it is not possible for DESC to estimate a range of possible loss. For regulatory matters that DESC cannot estimate, a statement to this effect is made in the description of the matter. Other matters may have progressed sufficiently through the regulatory process such that DESC is able to estimate a range of possible loss. For regulatory matters that DESC is able to reasonably estimate a range of possible losses, an estimated range of possible loss is provided, in excess of the accrued liability (if any) for such matters. Any estimated range is based on currently available information, involves elements of judgment and significant uncertainties and may not represent DESC’s maximum possible loss exposure. The circumstances of such regulatory matters will change from time to time and actual results may vary significantly from the current estimate. For current matters not specifically reported below, management does not anticipate that the outcome from such matters would have a material effect on DESC’s financial position, liquidity or results of operations.

Other Regulatory Matters

Other than the following matters, there have been no significant developments regarding the pending regulatory matters disclosed in Note 3 to the Consolidated Financial Statements in DESC's Annual Report on Form 10-K for the year ended December 31, 2020.

 

South Carolina Electric Base Rate Case

In August 2020, DESC filed its retail electric base rate case and schedules with the South Carolina Commission. DESC proposed a non-fuel, base rate increase of $178 million, or 7.75%, based on an adjusted test year data, effective on or after the first billing cycle of March 2021. The base rate increase was proposed to recover the significant investment in assets and operating resources required to serve an expanding customer base, maintain the safety, reliability and efficiency of DESC’s system and meet increasingly stringent reliability, security and environmental requirements for the benefit of South Carolina customers.  DESC presented an earned ROE of 5.90% based upon a fully-adjusted test period. The proposed rates would provide for an earned ROE equal to the current authorized earned ROE of 10.25% established in the previous rate case in 2012.  In January 2021, the South Carolina Commission approved a proposal made by the South Carolina Office of Regulatory Staff, and agreed to by DESC and other intervenors, to stay the base rate case due to the current economic conditions and to allow the parties more time to negotiate a settlement with a final order to be issued no later than August 2021.

 

In July 2021, DESC, the South Carolina Office of Regulatory Staff and other parties of record filed a comprehensive settlement agreement with the South Carolina Commission for approval. The comprehensive settlement agreement provides for a non-fuel, base rate increase of $62 million (resulting in a net increase of $36 million after considering an accelerated amortization of certain excess deferred income taxes) commencing with bills issued on September 1, 2021 and an authorized earned ROE of 9.50%. Additionally, DESC has agreed to commit up to $15 million to forgive retail electric customer balances that were more than 60 days past due as of May 31, 2021, and provide $15 million for energy efficiency upgrades and critical health and safety repairs to customer homes. Pursuant to the comprehensive settlement agreement, DESC would not file a retail electric base rate case prior to July 1, 2023, such that new rates would not be effective prior to January 1, 2024, absent unforeseen extraordinary economic or financial conditions that may include changes in corporate tax rates. In July 2021, the South Carolina Commission voted to approve the comprehensive settlement agreement with a final order expected to be issued in August 2021.

 

In connection with this matter, DESC recorded charges for both the three and six months ended June 30, 2021, of $249 million ($187 million after-tax) reflected within impairment of assets and other charges, including $237 million of regulatory assets associated with DESC’s purchases of its first mortgage bonds during 2019 that are no longer probable of recovery under the settlement agreement, and $18 million ($14 million after-tax) reflected within other income in its Consolidated Statements of Income.

 

Electric – Cost of Fuel

DESC’s retail electric rates include a cost of fuel component approved by the South Carolina Commission which may be adjusted periodically to reflect changes in the price of fuel purchased by DESC. In February 2021, DESC filed a proposal with the South Carolina Commission to increase the total fuel cost component of retail electric rates. DESC’s proposed adjustment would increase annual base fuel component recoveries by $36 million and is designed to recover DESC’s current base fuel costs, net of the existing over-collected balance, over the 12-month period beginning with the first billing cycle of May 2021. In addition, DESC proposed a decrease to its variable environmental component and an increase to its distributed energy resource components. In April 2021, the South Carolina Commission approved the filing.

Electric – Other

 

DESC has approval for a DSM rider through which it recovers expenditures related to its DSM programs. In January 2021, DESC filed an application with the South Carolina Commission seeking approval to recover $48 million of costs and net lost revenues associated with these programs, along with an incentive to invest in such programs. In April 2021, the South Carolina Commission approved the filing. In connection with the approval of the comprehensive settlement agreement in the South Carolina base rate case discussed above, the net lost revenue component of the DSM rider will be adjusted resulting in a recovery of $43 million commencing with bills issued on September 1, 2021.

DESC utilizes a pension costs rider approved by the South Carolina Commission which is designed to allow recovery of projected pension costs, including under-collected balances or net of over-collected balances, as applicable. The rider is typically reviewed for adjustment every 12 months with any resulting increase or decrease going into effect beginning with the first billing cycle in May. In February 2021, DESC requested that the South Carolina Commission approve an adjustment to this rider to decrease annual revenue by less than $1 million. In April 2021, the South Carolina Commission approved the filing.

 

Natural Gas Rates

In June 2021, DESC filed with the South Carolina Commission its monitoring report for the 12-month period ended March 31, 2021 with a total revenue requirement of $426 million. This represents a $9 million overall annual increase to its natural gas rates under the terms of the RSA effective with the first billing cycle of November 2021. This matter is pending.

  

 

DESC's natural gas tariffs include a PGA that provides for the recovery of actual gas costs incurred, including transportation costs. DESC’s gas rates are calculated using a methodology which may adjust the cost of gas monthly based on a 12-month rolling average, and its gas purchasing policies and practices are reviewed annually by the South Carolina Commission.

Regulatory Assets and Regulatory Liabilities

Rate-regulated utilities recognize in their financial statements certain revenues and expenses in different periods than do other enterprises. As a result, DESC has recorded regulatory assets and regulatory liabilities which are summarized in the following table. Except for NND Project costs and certain other unrecovered plant costs, substantially all regulatory assets are either explicitly excluded from rate base or are effectively excluded from rate base due to their being offset by related liabilities.

 

 

 

June 30,

 

 

December 31,

 

(millions)

 

2021

 

 

2020

 

Regulatory assets:

 

 

 

 

 

 

 

 

NND Project costs(1)

 

$

138

 

 

$

138

 

Deferred employee benefit plan costs(2)

 

 

8

 

 

 

9

 

Other unrecovered plant(3)

 

 

15

 

 

 

14

 

DSM programs(4)

 

 

23

 

 

 

29

 

AROs(5)

 

 

2

 

 

 

2

 

Cost of fuel and purchased gas under-collections(6)

 

 

—

 

 

 

1

 

Other

 

 

26

 

 

 

36

 

Regulatory assets - current

 

 

212

 

 

 

229

 

NND Project costs(1)

 

 

2,295

 

 

 

2,364

 

AROs(5)

 

 

311

 

 

 

309

 

Cost of reacquired debt(7)

 

 

11

 

 

 

243

 

Deferred employee benefit plan costs(2)

 

 

156

 

 

 

159

 

Deferred losses on interest rate derivatives(8)

 

 

300

 

 

 

308

 

Other unrecovered plant(3)

 

 

59

 

 

 

61

 

DSM programs(4)

 

 

46

 

 

 

46

 

Environmental remediation costs(9)

 

 

20

 

 

 

20

 

Deferred storm damage costs(10)

 

 

45

 

 

 

45

 

Deferred transmission operating costs(11)

 

 

76

 

 

 

63

 

Other(12)

 

 

141

 

 

 

108

 

Regulatory assets - noncurrent

 

 

3,460

 

 

 

3,726

 

Total regulatory assets

 

$

3,672

 

 

$

3,955

 

Regulatory liabilities:

 

 

 

 

 

 

 

 

Monetization of guaranty settlement(13)

 

$

67

 

 

$

67

 

Income taxes refundable through future rates(14)

 

 

36

 

 

 

21

 

Reserve for refunds to electric utility customers(15)

 

 

123

 

 

 

128

 

Cost of fuel and purchased gas over-collections(6)

 

 

38

 

 

 

58

 

Other

 

 

21

 

 

 

9

 

Regulatory liabilities - current

 

 

285

 

 

 

283

 

Monetization of guaranty settlement(13)

 

 

869

 

 

 

903

 

Income taxes refundable through future rates(14)

 

 

893

 

 

 

919

 

Asset removal costs(16)

 

 

572

 

 

 

564

 

Deferred gains on interest rate derivatives(8)

 

 

68

 

 

 

69

 

Reserve for refunds to electric utility customers(15)

 

 

475

 

 

 

540

 

Other

 

 

24

 

 

 

10

 

Regulatory liabilities - noncurrent

 

 

2,901

 

 

 

3,005

 

Total regulatory liabilities

 

$

3,186

 

 

$

3,288

 

 

(1)

Reflects expenditures associated with the NND Project, which pursuant to the SCANA Merger Approval Order, will be recovered from electric service customers over a 20-year period ending in 2039. See Note 10 for more information.

(2)

Employee benefit plan costs have historically been recovered as they have been recorded under GAAP. Deferred employee benefit plan costs represent amounts of pension and other postretirement benefit costs which were accrued as liabilities and treated as regulatory assets pursuant to FERC guidance, and costs deferred pursuant to specific South Carolina Commission regulatory orders. DESC expects to recover deferred pension costs through utility rates over periods through 2044. DESC expects to recover other deferred benefit costs through utility rates, primarily over average service periods of participating employees up to 11 years.

(3)

Represents the carrying value of coal-fired generating units, including related materials and supplies inventory, retired from service prior to being fully depreciated. DESC is amortizing these amounts through cost of service rates following deprecation amounts that were designed to recover the retired units’ cost over their previous estimated remaining useful lives, which has been estimated to be through 2025. Based on

current projections of remaining decommissioning costs, projected recovery is expected to extend to 2028. Unamortized amounts are included in rate base and are earning a current return.

(4)

Represents deferred costs associated with electric demand reduction programs, and such deferred costs are currently being recovered over three years through an approved rate rider.

(5)

Represents deferred depreciation and accretion expense related to legal obligations associated with the future retirement of generation, transmission and distribution properties. The AROs primarily relate to DESC’s electric generating facilities, including Summer, and are expected to be recovered over the related property lives and periods of decommissioning which may range up to approximately 105 years.

(6)

Represents amounts under- or over-collected from customers pursuant to the cost of fuel and purchased gas components approved by the South Carolina Commission.

(7)

During the second quarter of 2021, DESC recorded a charge of $237 million ($178 million after-tax) in impairment of assets and other charges to write-off the balance of a regulatory asset that is no longer probable of recovery under the settlement agreement approved in DESC’s retail electric base rate case. See South Carolina Electric Base Rate Case discussed above for more information.

(8)

Represents (i) the changes in fair value and payments made or received upon settlement of certain interest rate derivatives designated as cash flow hedges and (ii) the changes in fair value and payments made or received upon settlement of certain other interest rate derivatives not so designated. The amounts recorded with respect to (i) are expected to be amortized to interest expense over the lives of the underlying debt through 2043.The amounts recorded with respect to (ii) are expected to be similarly amortized to interest expense through 2065.

(9)

Reflects amounts associated with the assessment and clean-up of sites currently or formerly owned by DESC. Such remediation costs are expected to be recovered over periods of up to 15 years. See Note 10 for more information.

(10)

Represents storm restoration costs for which DESC expects to recover through customer rates over approximately 10 years pursuant to the settlement agreement approved in DESC’s retail electric base rate case.

(11)

Includes deferred depreciation and property taxes associated with certain transmission assets for which DESC expects to recover from customers over approximately 40 years pursuant to the settlement agreement approved in DESC’s retail electric base rate case.

(12)

Various other regulatory assets are expected to be recovered through rates over varying periods through 2047.

(13)

Represents proceeds related to the monetization of the Toshiba Settlement. In accordance with the SCANA Merger Approval Order, this balance, net of amounts that may be required to satisfy liens, will be refunded to electric customers over a 20-year period ending in 2039. See Note 12 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020.

(14)

Includes (i) excess deferred income taxes arising from the remeasurement of deferred income taxes in connection with the enactment of the 2017 Tax Reform Act (certain of which are protected under normalization rules and will be amortized over the remaining lives of related property, and certain of which will be amortized to the benefit of customers over prescribed periods as instructed by regulators) and (ii) deferred income taxes arising from investment tax credits, offset by (iii) deferred income taxes that arise from utility operations that have not been included in customer rates (a portion of which relate to depreciation and are expected to be recovered over the remaining lives of the related property which may range up to 85 years). See Note 6 for more information.

(15)

Reflects amounts previously collected from retail electric customers of DESC for the NND Project to be credited to customers over an estimated 11-year period effective February 2019 in connection with the SCANA Merger Approval Order. See Note 12 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020.

(16)

Represents estimated net collections through depreciation rates of amounts to be expended for the removal of assets in the future.

 

Regulatory assets have been recorded based on the probability of their recovery. All regulatory assets represent incurred costs that may be deferred under GAAP for regulated operations. The South Carolina Commission or FERC has reviewed and approved through specific orders certain of the items shown as regulatory assets. In addition, regulatory assets include, but are not limited to, certain costs which have not been specifically approved for recovery by one of these regulatory agencies. While such costs are not currently being recovered, management believes they would be allowable under existing rate-making concepts embodied in rate orders or applicable state law and expects to recover these costs through rates in future periods.
v3.21.2
Revenue Recognition
 6 Months Ended
Jun. 30, 2021
Revenue From Contract With Customer [Abstract]  
Revenue Recognition

3. REVENUE RECOGNITION

DESC has disaggregated operating revenues by customer class as follows:

 

 

 

Three Months Ended

 

 

Three Months Ended

 

 

Six Months Ended

 

 

Six Months Ended

 

 

 

June 30, 2021

 

 

June 30, 2020

 

 

June 30, 2021

 

 

June 30, 2020

 

(millions)

 

Electric

 

 

Gas

 

 

Electric

 

 

Gas

 

 

Electric

 

 

Gas

 

 

Electric

 

 

Gas

 

Customer class:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Residential

 

$

271

 

 

$

38

 

 

$

261

 

 

$

33

 

 

$

546

 

 

$

136

 

 

$

513

 

 

$

112

 

Commercial

 

 

199

 

 

 

26

 

 

 

177

 

 

 

20

 

 

 

374

 

 

 

65

 

 

 

352

 

 

 

53

 

Industrial

 

 

95

 

 

 

18

 

 

 

83

 

 

 

12

 

 

 

183

 

 

 

40

 

 

 

163

 

 

 

29

 

Other

 

 

38

 

 

 

7

 

 

 

27

 

 

 

4

 

 

 

71

 

 

 

12

 

 

 

57

 

 

 

8

 

Revenues from contracts with

   customers

 

 

603

 

 

 

89

 

 

 

548

 

 

 

69

 

 

 

1,174

 

 

 

253

 

 

 

1,085

 

 

 

202

 

Other revenues

 

 

—

 

 

 

—

 

 

 

7

 

 

 

—

 

 

 

8

 

 

 

1

 

 

 

9

 

 

 

—

 

Total Operating Revenues

 

$

603

 

 

$

89

 

 

$

555

 

 

$

69

 

 

$

1,182

 

 

$

254

 

 

$

1,094

 

 

$

202

 

 

Contract liabilities represent the obligation to transfer goods or services to a customer for which consideration has already been received from the customer. DESC had contract liability balances of $7 million and $5 million at June 30, 2021 and December 31, 2020, respectively. During the six months ended June 30, 2021 and 2020, DESC recognized revenue of $3 million and $5 million, respectively, from the beginning contract liability balances as DESC fulfilled its obligations to provide service to its customers. Contract liabilities are recorded in customer deposits and customer prepayments in the Consolidated Balance Sheets.
v3.21.2
Equity
 6 Months Ended
Jun. 30, 2021
Equity [Abstract]  
Equity

4. EQUITY

For all periods presented, DESC's authorized shares of common stock, no par value, were 50 million, of which 40.3 million were issued and outstanding, and DESC's authorized shares of preferred stock, no par value, were 20 million, of which 1,000 shares were issued and outstanding. All outstanding shares of common and preferred stock are held by SCANA.

In July 2021, Dominion Energy issued $104 million of shares of Dominion Energy common stock to satisfy DESC’s obligation under a settlement agreement for the FILOT litigation discussed in Note 10. In August 2021, Dominion Energy issued $45 million of shares of Dominion Energy common stock to satisfy DESC’s obligation for the initial payment under a settlement agreement with the SCDOR discussed in Note 10. In connection with these transactions, DESC will record equity contributions from Dominion Energy in the third quarter of 2021.

There have been no material changes to the dividend restrictions affecting DESC described in Note 5 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020.
v3.21.2
Long-Term and Short-Term Debt
 6 Months Ended
Jun. 30, 2021
Debt Disclosure [Abstract]  
Long-Term and Short-Term Debt

5. LONG-TERM AND SHORT-TERM DEBT

DESC's short-term financing is supported through its access as co-borrower to Dominion Energy’s $6.0 billion joint revolving credit facility, as amended in June 2021. The facility can be used for working capital, as support for the combined commercial paper programs of DESC, Dominion Energy, Virginia Power and Questar Gas, and for other general corporate purposes.

At June 30, 2021, DESC's share of commercial paper and letters of credit outstanding under its joint credit facility with Dominion Energy, was as follows:

 

(millions)

 

Facility Limit

 

 

Outstanding

Commercial Paper

 

 

Outstanding

Letters of Credit

 

Joint revolving credit facility(1)

 

$

1,000

 

 

$

60

 

 

$

—

 

 

(1)

A maximum of $1.0 billion of the facility is available to DESC, assuming adequate capacity is available after giving effect to uses by co-borrowers Dominion Energy, Virginia Power and Questar Gas. The sub-limit for DESC is set within the facility limit but can be changed at the option of the co-borrowers multiple times per year. At June 30, 2021, the sub-limit for DESC was $500 million. If DESC has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from DESC's parent or from Dominion Energy. This credit facility matures in June 2026, with the potential to be extended by the borrowers to June 2028. The credit facility can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $1.0 billion (or the sub-limit, whichever is less) of letters of credit.

In January 2021, DESC and GENCO each applied to FERC for a two-year short-term borrowing authorization. In March 2021, FERC granted DESC authority through March 2023 to issue short-term indebtedness (pursuant to Section 204 of the Federal Power Act) in amounts not to exceed $2.2 billion outstanding with maturity dates of one year or less. In addition, in March 2021, FERC granted GENCO authority through March 2023 to issue short-term indebtedness not to exceed $200 million outstanding with maturity dates of one year or less.

DESC is obligated with respect to an aggregate of $68 million of industrial revenue bonds which are secured by letters of credit. These letters of credit expire, subject to renewal, in the fourth quarter of 2021.

In July 2021, DESC redeemed the remaining principal outstanding of $30 million of its 3.22% first mortgage bonds, plus accrued interest. The bonds would have otherwise matured in October 2021.

DESC has FERC approval to enter into an inter-company credit agreement with Dominion Energy under which DESC may have short-term borrowings outstanding up to $900 million. At June 30, 2021 and December 31, 2020, DESC had borrowings outstanding under this credit agreement totaling $542 million and $149 million, respectively, which are recorded in affiliated and related party payables in DESC’s Consolidated Balance Sheets. For the three and six months ended June 30, 2021, DESC recorded interest charges of $2 million and $4 million, respectively. For the three and six months ended June 30, 2020, DESC recorded interest charges of $3 million and $5 million, respectively.

Fuel Company and GENCO participated in a SCANA utility money pool until January 2021, when that utility money pool was closed, and Fuel Company and GENCO joined the Dominion Energy utility money pool with other regulated subsidiaries of Dominion Energy. Money pool borrowings and investments bore interest at short-term market rates. For the six months ended June 30, 2021, DESC recorded interest income from money pool transactions of less than $1 million, and for the same period DESC recorded interest expense from money pool transactions of less than $1 million. For the three and six months ended June 30, 2020, DESC recorded interest income from money pool transactions of $1 million and $2 million, respectively, and for the same periods DESC recorded interest expense from money pool transactions $1 million and $2 million, respectively. At December 31, 2020, DESC had outstanding money pool borrowings due to an affiliate of $206 million and investments due from an affiliate of $15 million. On its Consolidated Balance Sheet, DESC includes money pool borrowings within affiliated and related party payables and money pool investments within affiliated and related party receivables.
v3.21.2
Income Taxes
 6 Months Ended
Jun. 30, 2021
Income Tax Disclosure [Abstract]  
Income Taxes

6. INCOME TAXES

 

DESC’s effective tax rate for the six months ended June 30, 2021 is 33.6% compared to 21.5% for the six months ended June 30, 2020. DESC’s effective tax rate for the six months ended June 30, 2021 is primarily attributable to loss before income tax resulting from charges in connection with the comprehensive settlement agreement discussed in Note 2.

DESC has recorded an estimate of excess deferred income tax amortization in 2021. The reversal of these excess deferred income taxes will impact the effective tax rate and rates charged to customers. See Note 3 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020 for more information.

As of June 30, 2021, there have been no material changes in DESC’s unrecognized tax benefits. See Note 7 to the Consolidated Financial Statements in DESC's Annual Report on Form 10-K for the year ended December 31, 2020 for a discussion of these unrecognized tax benefits.
v3.21.2
Derivative Financial Instruments
 6 Months Ended
Jun. 30, 2021
Derivative Instruments And Hedging Activities Disclosure [Abstract]  
Derivative Financial Instruments

7. DERIVATIVE FINANCIAL INSTRUMENTS

DESC’s accounting policies, objectives, and strategies for using derivative instruments are discussed in Note 2 in the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020. DESC uses derivative instruments such as physical forwards to manage its commodity risk of its business operations. See Note 8 for further information about fair value measurements and associated valuation methods for derivatives.

Derivative assets and liabilities are presented gross on the Consolidated Balance Sheets. DESC’s derivative contracts include over-the-counter transactions. Over-the-counter contracts are bilateral contracts that are transacted directly with a third party. Certain over-the-counter contracts contain contractual rights of setoff through master netting arrangements and contract default provisions. In addition, the contracts are subject to conditional rights of setoff through counterparty nonperformance, insolvency or other conditions.

In general, most over-the-counter transactions are subject to collateral requirements. Types of collateral for over-the-counter contracts include cash, letters of credit and, in some cases, other forms of security, none of which are subject to restrictions. Cash collateral, as presented in the table below, is used to offset derivative assets and liabilities.

Certain of DESC’s derivative instruments contain credit-related contingent provisions. These provisions require DESC to provide collateral upon the occurrence of specific events, primarily a credit rating downgrade. If the credit-related contingent features underlying the instruments that are in a liability position and not fully collateralized with cash were fully triggered as of June 30, 2021 and December 31, 2020, DESC would have been required to post $11 million and $10 million, respectively, of additional collateral to its counterparties. The collateral that would be required to be posted includes the impacts of any amounts already posted for derivatives per contractual terms. DESC had posted $11 million and $1 million, respectively, of collateral at June 30, 2021 and December 31, 2020 related to derivatives with credit-related contingent provisions that are in a liability position and not fully collateralized with cash. The aggregate fair value of all derivative instruments with credit-related contingent provisions that are in a liability position and not fully collateralized with cash was $22 million and $11 million at June 30, 2021 and December 31, 2020, respectively.

The table below presents derivative balances by type of financial instrument, if the gross amounts recognized in the Consolidated Balance Sheets were netted with derivative instruments and cash collateral received or paid. DESC’s commodity derivative assets are not subject to a master netting agreement or similar arrangement.

 

 

 

June 30, 2021

 

 

December 31, 2020

 

 

 

Gross Amounts Not Offset in the Consolidated

Balance Sheet

 

 

Gross Amounts Not Offset in the Consolidated

Balance Sheet

 

(millions)

 

Gross

Liabilities

Presented in the

Consolidated

Balance Sheet(1)

 

 

Financial

Instruments

 

 

Cash

Collateral

Paid

 

 

Net

Amounts

 

 

Gross

Liabilities

Presented in the

Consolidated

Balance Sheet(1)

 

 

Financial

Instruments

 

 

Cash

Collateral

Paid

 

 

Net

Amounts

 

Interest rate contracts:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Over-the-counter

 

$

22

 

 

$

—

 

 

$

11

 

 

$

11

 

 

$

27

 

 

$

—

 

 

$

17

 

 

$

10

 

Total derivatives

 

$

22

 

 

$

—

 

 

$

11

 

 

$

11

 

 

$

27

 

 

$

—

 

 

$

17

 

 

$

10

 

1) Excludes $28 million and $— million of derivative liabilities at June 30, 2021 and December 31, 2020, respectively, which are not subject to master netting or similar arrangements.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Volumes

The following table presents the volume of derivative activity at June 30, 2021. These volumes are based on open derivative positions and represent the combined absolute value of their long and short positions.

 

 

Current

 

 

Noncurrent

 

Electricity (MWh):

 

 

 

 

 

 

 

 

Fixed price

 

 

1,642,960

 

 

 

23,508,146

 

Interest rate(1) (millions)

 

$

—

 

 

$

71

 

(1)

Maturity is determined based on final settlement period.

Fair Value and Gains and Losses on Derivative Instruments

The following tables present the fair values of derivatives and where they are presented in the Consolidated Balance Sheets:

 

(millions)

 

Fair Value -

Derivatives

under Hedge

Accounting

 

 

Fair Value -

Derivatives not

under Hedge

Accounting

 

 

Total Fair Value

 

At June 30, 2021

 

 

 

 

 

 

 

 

 

 

 

 

ASSETS

 

 

 

 

 

 

 

 

 

 

 

 

Current Assets

 

 

 

 

 

 

 

 

 

 

 

 

Commodity

 

$

—

 

 

$

5

 

 

$

5

 

Total current derivative assets(1)

 

 

—

 

 

 

5

 

 

 

5

 

Noncurrent Assets

 

 

 

 

 

 

 

 

 

 

 

 

Commodity

 

 

—

 

 

 

10

 

 

 

10

 

Total noncurrent derivative assets(2)

 

 

—

 

 

 

10

 

 

 

10

 

Total derivative assets

 

$

—

 

 

$

15

 

 

$

15

 

LIABILITIES

 

 

 

 

 

 

 

 

 

 

 

 

Current Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

Interest rate

 

$

1

 

 

$

1

 

 

$

2

 

Total current derivative liabilities(3)

 

 

1

 

 

 

1

 

 

 

2

 

Noncurrent Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

Commodity

 

 

—

 

 

 

28

 

 

 

28

 

Interest rate

 

 

12

 

 

 

8

 

 

 

20

 

Total noncurrent derivative liabilities(4)

 

 

12

 

 

 

36

 

 

 

48

 

Total derivative liabilities

 

$

13

 

 

$

37

 

 

$

50

 

At December 31, 2020

 

 

 

 

 

 

 

 

 

 

 

 

LIABILITIES

 

 

 

 

 

 

 

 

 

 

 

 

Current Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

Interest rate

 

$

1

 

 

$

1

 

 

$

2

 

Total current derivative liabilities(3)

 

 

1

 

 

 

1

 

 

 

2

 

Noncurrent Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

Interest rate

 

 

15

 

 

 

10

 

 

 

25

 

Total noncurrent derivative liabilities(4)

 

 

15

 

 

 

10

 

 

 

25

 

Total derivative liabilities

 

$

16

 

 

$

11

 

 

$

27

 

 

(1)

Current derivative assets are presented in other current assets in the Consolidated Balance Sheets.

(2)

Noncurrent derivative assets are presented in other deferred debits and other assets in the Consolidated Balance Sheets.

(3)

Current derivative liabilities are presented in other current liabilities in the Consolidated Balance Sheets.

(4)

Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in the Consolidated Balance Sheets.

The following tables present the gains and losses on derivatives, as well as where the associated activity is presented in the Consolidated Balance Sheets and Statements of Comprehensive Income (Loss):

Derivatives in Cash Flow Hedging Relationships

 

(millions)

Increase (Decrease)

in Derivatives

Subject to

Regulatory

Treatment(1)

 

Three Months Ended June 30, 2021

 

 

 

Derivative type and location of gains (losses):

 

 

 

Interest rate

$

(1

)

Total

$

(1

)

Three Months Ended June 30, 2020

 

 

 

Derivative type and location of gains (losses):

 

 

 

Interest rate

$

2

 

Total

$

2

 

Six Months Ended June 30, 2021

 

 

 

Derivative type and location of gains (losses):

 

 

 

Interest rate

$

6

 

Total

$

6

 

Six Months Ended June 30, 2020

 

 

 

Derivative type and location of gains (losses):

 

 

 

Interest rate

$

(4

)

Total

$

(4

)

 

(1)

Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/ liabilities have no associated effect in the Consolidated Statements of Comprehensive Income (Loss).

  

 

Derivatives Not Designated as Hedging Instrument

There were no gains and losses on derivatives not designated as hedging instruments for both the three months ended June 30, 2021 and June 30, 2020.

(millions)

 

 

 

Amount of Gain (Loss)

Recognized in Income on

Derivatives(1)

 

Six Months Ended June 30,

 

Location

 

2021

 

 

2020

 

Derivative type and location of gains (losses):

 

 

 

 

 

 

 

 

 

 

Interest rate contracts:

 

Interest charges

 

$

(1

)

 

$

—

 

Total interest rate contracts

 

 

 

$

(1

)

 

$

—

 

(1)

Includes derivative activity amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in the Consolidated Statements of Comprehensive Income (Loss).
v3.21.2
Fair Value Measurements, Including Derivatives
 6 Months Ended
Jun. 30, 2021
Fair Value Disclosures [Abstract]  
Fair Value Measurements, Including Derivatives

8. FAIR VALUE MEASUREMENTS, INCLUDING DERIVATIVES

DESC’s fair value measurements are made in accordance with the policies discussed in Note 9 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020. See Note 7 in this report for further information about DESC’s derivatives and hedge accounting activities. DESC applies fair value measurements to certain assets and liabilities including commodity, in addition to interest rate derivative instruments.

 

Inputs and Assumptions

When evaluating pricing information provided by Designated Contract Market settlement pricing, other pricing services, or brokers, DESC considers the ability to transact at the quoted price, i.e. if the quotes are based on an active market or an inactive market and to the extent which pricing models are used, if pricing is not readily available. If pricing information from external sources is not available, or if DESC believes that observable pricing is not indicative of fair value, judgment is required to develop the estimates of fair value. In those cases the unobservable inputs are developed and substantiated using historical information, available market data, third-party data and statistical analysis. Periodically, inputs to valuation models are reviewed and revised as needed, based on historical information, updated market data, market liquidity and relationships and changes in third-party sources. The inputs and assumptions used in measuring fair value include the following for commodity derivative contracts:

 

 

 

•

Forward commodity prices

 

•

Transaction prices

 

•

Volumes

 

•

Commodity location

 

•

Interest rates

 

•

Credit quality of counterparties and the Companies

 

•

Credit enhancements

 

•

Time value

Level 3 Valuations

DESC enters into physical forwards contracts, which are considered Level 3 as they have one or more inputs that are not observable and are significant to the valuation. The discounted cash flow method is used to value Level 3 physical forwards contracts. The discounted cash flow model for forwards calculates mark-to-market valuations based on forward market prices, original transaction prices, volumes, risk-free rate of return, and credit spreads. For Level 3 fair value measurements, certain forward market prices are considered unobservable.

The following table presents DESC’s quantitative information about Level 3 fair value measurements at June 30, 2021. The range and weighted average are presented in dollars for market price inputs.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fair Value

(millions)

 

 

Valuation Techniques

 

Unobservable Input

 

 

Range

 

Weighted

Average(1)

 

Assets

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Physical forwards:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Electricity

 

$

15

 

 

Discounted cash flow

 

Market price (per MWh)

(2)

 

23 - 54

 

 

35

 

Total assets

 

$

15

 

 

 

 

 

 

 

 

 

 

 

 

Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Physical forwards:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Electricity

 

$

28

 

 

Discounted cash flow

 

Market price (per MWh)

(2)

 

23 - 55

 

 

35

 

Total liabilities

 

$

28

 

 

 

 

 

 

 

 

 

 

 

 

(1)   Averages weighted by volume.

(2)Represents market prices beyond defined terms for Levels 1 and 2.

 

Sensitivity of the fair value measurements to changes in the significant unobservable inputs is as follows:

 

Significant Unobservable

Inputs

 

Position

 

Change to Input

 

Impact on Fair Value

Measurement

Market price

 

Buy

 

Increase (decrease)

 

Gain (loss)

Market price

 

Sell

 

Increase (decrease)

 

Loss (gain)

Recurring Fair Value Measurements

The following table presents DESC’s liabilities that are measured at fair value on a recurring basis for each hierarchy level, including both current and noncurrent portions:

 

(millions)

 

Level 1

 

 

Level 2

 

 

Level 3

 

 

Total

 

At June 30, 2021

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Assets

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Commodity

 

$

—

 

 

$

—

 

 

$

15

 

 

$

15

 

Total assets

 

$

—

 

 

$

—

 

 

$

15

 

 

$

15

 

Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Commodity

 

$

—

 

 

$

—

 

 

$

28

 

 

$

28

 

Interest rate

 

 

—

 

 

 

22

 

 

 

—

 

 

 

22

 

Total liabilities

 

$

—

 

 

$

22

 

 

$

28

 

 

$

50

 

At December 31, 2020

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Interest rate

 

$

—

 

 

$

27

 

 

$

—

 

 

$

27

 

Total liabilities

 

$

—

 

 

$

27

 

 

$

—

 

 

$

27

 

 

 

The following table presents the net change in DESC's assets and liabilities measured at fair value on a recurring basis and included in the Level 3 fair value category. There were no net changes in assets and liabilities measured at fair value on a recurring basis and included in the Level 3 fair value category for the three and six months ended June 30, 2020.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Three Months Ended

Six Months Ended

 

 

 

June 30,

June 30,

 

 

 

2021

 

 

2021

 

(millions)

 

 

 

 

 

 

 

 

Beginning balance

 

$

—

 

 

$

—

 

Total realized and unrealized losses:

 

 

 

 

 

 

 

 

Included in regulatory assets/liabilities

 

 

(13

)

 

 

(13

)

Ending balance

 

$

(13

)

 

$

(13

)

 

There were no unrealized gains or losses included in earnings in the Level 3 fair value category relating to assets/liabilities still held atthe reporting date for the three and six months ended June 30, 2021.

 

Fair Value of Financial Instruments

Substantially all of DESC’s financial instruments are recorded at fair value, with the exception of the instruments described below, which are reported at historical cost. Estimated fair values have been determined using available market information and valuation methodologies considered appropriate by management. The carrying amount of financial instruments classified within current assets and current liabilities are representative of fair value because of the short-term nature of these instruments. For financial instruments that are not recorded at fair value, the carrying amounts and estimated fair values are as follows:

 

 

 

June 30, 2021

 

 

December 31, 2020

 

(millions)

 

Carrying

Amount

 

 

Estimated

Fair Value(1)

 

 

Carrying

Amount

 

 

Estimated

Fair Value(1)

 

Long-term debt(2)

 

$

3,360

 

 

$

4,515

 

 

$

3,360

 

 

$

4,748

 

Affiliated long-term debt

 

 

230

 

 

 

230

 

 

 

230

 

 

 

230

 

 

(1)

Fair value is estimated using market prices, where available, and interest rates currently available for issuance of debt with similar terms and remaining maturities. All fair value measurements are classified as Level 2. The carrying amount of debt issuances with short-term maturities and variable rates refinanced at current market rates is a reasonable estimate of their fair value.

(2)   Carrying amount includes current portions included in securities due within one year and amounts which represent the unamortized debt issuance costs and discount or premium.

 

 
v3.21.2
Employee Benefit Plans
 6 Months Ended
Jun. 30, 2021
Compensation And Retirement Disclosure [Abstract]  
Employee Benefit Plans

9. EMPLOYEE BENEFIT PLANS

Components of net periodic benefit cost recorded by DESC were as follows:

(millions)

 

Pension Benefits

 

 

Other Postretirement Benefits

 

Three Months Ended June 30,

 

2021

 

 

2020

 

 

2021

 

 

2020

 

Service cost

 

$

1

 

 

$

4

 

 

$

—

 

 

$

1

 

Interest cost

 

 

5

 

 

 

6

 

 

 

2

 

 

 

2

 

Expected return on assets

 

 

(12

)

 

 

(11

)

 

 

—

 

 

 

—

 

Amortization of actuarial losses

 

 

1

 

 

 

1

 

 

 

—

 

 

 

—

 

Net periodic benefit cost (credit)

 

$

(5

)

 

$

—

 

 

$

2

 

 

$

3

 

Six Months Ended June 30,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Service cost

 

$

4

 

 

$

7

 

 

$

1

 

 

$

2

 

Interest cost

 

 

10

 

 

 

12

 

 

 

3

 

 

 

4

 

Expected return on assets

 

 

(24

)

 

 

(22

)

 

 

—

 

 

 

—

 

Amortization of actuarial losses

 

 

3

 

 

 

3

 

 

 

—

 

 

 

—

 

Net periodic benefit cost (credit)

 

$

(7

)

 

$

—

 

 

$

4

 

 

$

6

 

 

 

During the three and six months ended June 30, 2021, DESC made no contributions to its pension trust and does not expect to make any such contributions in 2021. DESC recovers current pension costs through either a rate rider that may be adjusted annually for retail electric operations or through cost of service rates for gas operations.
v3.21.2
Commitments And Contingencies
 6 Months Ended
Jun. 30, 2021
Commitments And Contingencies Disclosure [Abstract]  
Commitments and Contingencies

10. COMMITMENTS AND CONTINGENCIES

As a result of issues generated in the ordinary course of business, DESC is involved in legal proceedings before various courts and is periodically subject to governmental examinations (including by regulatory authorities), inquiries and investigations. Certain legal proceedings and governmental examinations involve demands for unspecified amounts of damages, are in an initial procedural phase, involve uncertainty as to the outcome of pending appeals or motions, or involve significant factual issues that need to be resolved, such that it is not possible for DESC to estimate a range of possible loss. For such matters that DESC cannot estimate, a statement to this effect is made in the description of the matter. Other matters may have progressed sufficiently through the litigation or investigative processes such that DESC is able to estimate a range of possible loss. For legal proceedings and governmental examinations that DESC is able to reasonably estimate a range of possible losses, an estimated range of possible loss is provided, in excess of the accrued liability (if any) for such matters. Any accrued liability is recorded on a gross basis with a receivable also recorded for any probable insurance recoveries. Estimated ranges of loss are inclusive of legal fees and net of any anticipated insurance recoveries. Any estimated range is based on currently available information and involves elements of judgment and significant uncertainties. Any estimated range of possible loss may not represent DESC’s maximum possible loss exposure. The circumstances of such legal proceedings and governmental examinations will change from time to time and actual results may vary significantly from the current estimate. For current proceedings not specifically reported below, management does not anticipate that the liabilities, if any, arising from such proceedings would have a material effect on DESC’s financial position, liquidity or results of operations.

Environmental Matters

DESC is subject to costs resulting from a number of federal, state and local laws and regulations designed to protect human health and the environment. These laws and regulations affect future planning and existing operations. They can result in increased capital, operating and other costs as a result of compliance, remediation, containment and monitoring obligations.

From a regulatory perspective, DESC and GENCO continually monitor and evaluate their current and projected emission levels and strive to comply with all state and federal regulations regarding those emissions. DESC and GENCO participate in the SO2 and NOX emission allowance programs with respect to coal plant emissions and also have constructed additional pollution control equipment at their coal-fired electric generating plants. These actions are expected to address many of the rules and regulations discussed herein.

Air

The CAA, as amended, is a comprehensive program utilizing a broad range of regulatory tools to protect and preserve the nation's air quality. At a minimum, states are required to establish regulatory programs to meet applicable requirements of the CAA. However, states may choose to develop regulatory programs that are more restrictive. Many of DESC’s facilities are subject to the CAA’s permitting and other requirements.

Ozone Standards

The EPA published final non-attainment designations for the October 2015 ozone standard in June 2018 with states required to develop plans to address the new standard. Until the states have developed implementation plans for the standard, DESC is unable to predict whether or to what extent the new rules will ultimately require additional controls. The expenditures required to implement additional controls could have a material impact on DESC’s results of operations and cash flows.

ACE Rule

In July 2019, the EPA published the final rule informally referred to as the ACE Rule, as a replacement for the Clean Power Plan. The ACE Rule regulated GHG emissions from existing coal-fired power plants pursuant to Section 111(d) of the CAA and required states to develop plans by July 2022 establishing unit-specific performance standards for existing coal-fired power plants. In January 2021, the U.S. Court of Appeals for the D.C. Circuit vacated the ACE Rule and remanded it to the EPA. This decision would take effect upon issuance of the court’s mandate. In March 2021, the court issued a partial mandate vacating and remanding all parts of the ACE Rule except for the portion of the ACE Rule that repealed the Clean Power Plan. While the EPA has stated its intention to replace the ACE Rule, it is unknown at this time if or how the EPA will issue a replacement for the ACE Rule and how that replacement will affect DESC’s operations, financial condition and/or cash flows.

Carbon Regulations

In August 2016, the EPA issued a draft rule proposing to reaffirm that a source’s obligation to obtain a PSD or Title V permit for GHGs is triggered only if such permitting requirements are first triggered by non-GHG, or conventional, pollutants that are regulated by the New Source Review program, and exceed a significant emissions rate of 75,000 tons per year of CO2 equivalent emissions. Until the EPA ultimately takes final action on this rulemaking, DESC cannot predict the impact to its results of operations, financial condition and/or cash flows.

In December 2018, the EPA proposed revised Standards of Performance for Greenhouse Gas Emissions from New, Modified, and Reconstructed Stationary Sources. The proposed rule would amend the previous determination that the best system of emission reduction for newly constructed coal-fired steam generating units is no longer partial carbon capture and storage. Instead, the proposed revised best system of emission reduction for this source category is the most efficient demonstrated steam cycle (e.g., supercritical steam conditions for large units and subcritical steam conditions for small units) in combination with best operating practices. In January 2021, the EPA published a final rule affirming that fossil fuel-fired electric generating units meet the requirement that a source category “significantly contribute” to endangering air pollution for the purposes of regulating GHG emissions from new, modified and reconstructed stationary sources. The January 2021 rule also established a threshold for the “significant contribution” threshold that would have meant that no other source category, such as oil and gas facilities, petroleum refineries, and boilers, would meet that requirement at this time. In April 2021, the U.S. Court of Appeals for the D.C. Circuit granted an unopposed motion by the EPA to vacate and remand the January 2021 rule. The proposed revision to the performance standards for coal-fired steam generating units remains pending. Until the EPA ultimately takes final action on this rulemaking, DESC cannot predict the impact to its results of operations, financial condition and/or cash flows.

Water

The CWA, as amended, is a comprehensive program requiring a broad range of regulatory tools including a permit program to authorize and regulate discharges to surface waters with strong enforcement mechanisms. DESC must comply with applicable aspects of the CWA programs at its operating facilities.

Regulation 316(b)

 

In October 2014, the final regulations under Section 316(b) of the CWA that govern existing facilities and new units at existing facilities that employ a cooling water intake structure and that have flow levels exceeding a minimum threshold became effective. The rule establishes a national standard for impingement based on seven compliance options, but forgoes the creation of a single technology standard for entrainment. Instead, the EPA has delegated entrainment technology decisions to state regulators. State regulators are to make case-by-case entrainment technology determinations after an examination of five mandatory facility-specific factors, including a social cost-benefit test, and six optional facility-specific factors. The rule governs all electric generating stations with water withdrawals above two MGD, with a heightened entrainment analysis for those facilities over 125 MGD. DESC has five facilities that are subject to the final regulations. DESC is also working with the EPA and state regulatory agencies to assess the applicability of Section 316(b) to five hydroelectric facilities. DESC anticipates that it may have to install impingement control technologies at certain of these stations that have once-through cooling systems. DESC is currently evaluating the need or potential for entrainment controls under the final rule as these decisions will be made on a case-by-case basis after a thorough review of detailed biological, technology, cost and benefit studies. DESC is conducting studies and implementing plans as required by the rule to determine appropriate intake structure modifications at certain facilities to ensure compliance with this rule. While the impacts of this rule could be material to DESC’s results of operations, financial condition and/or cash flows, the existing regulatory framework in South Carolina provides rate recovery mechanisms that could substantially mitigate any such impacts for DESC.

 

Effluent Limitations Guidelines

 

In September 2015, the EPA released a final rule to revise the ELG Rule. The final rule established updated standards for wastewater discharges that apply primarily at coal and oil steam generating stations. Affected facilities are required to convert from wet to dry or closed cycle coal ash management, improve existing wastewater treatment systems and/or install new wastewater treatment technologies in order to meet the new discharge limits. In April 2017, the EPA granted two separate petitions for reconsideration of the final ELG Rule and stayed future compliance dates in the rule. Also in April 2017, the U.S. Court of Appeals for the Fifth Circuit granted the EPA’s request for a stay of the pending consolidated litigation challenging the rule while the EPA addresses the petitions for reconsideration. In September 2017, the EPA signed a rule to postpone the earliest compliance dates for certain waste streams regulations in the final ELG Rule from November 2018 to November 2020; however, the latest date for compliance for these regulations was December 2023. In October 2020, the EPA released the final rule that extends the latest dates for compliance. Individual facilities’ compliance dates will vary based on circumstances and the determination by state regulators and may range from 2021 to 2028. While the impacts of this rule could be material to DESC’s results of operations, financial condition and/or cash flows, as DESC expects that wastewater treatment technology retrofits and modifications to the bottom ash handling systems at the Williams and Wateree generating stations will be required, the existing regulatory framework in South Carolina provides rate recovery mechanisms that could substantially mitigate any such impacts for DESC.

 

 

Capacity Use Area

In November 2019, a new CUA was established in the counties surrounding the Cope Generating Station (Western Capacity Use Area) under the South Carolina Groundwater Use and Reporting Regulation. Under the regulation any groundwater well in a CUA that withdraws above three million gallons per month must be permitted. The Cope Generating Station is located within this new Western Capacity Use Area. Cope has been using four deep groundwater wells for cooling water and other house loads since 1996. Prior to designation of the new Western Capacity Use Area, the wells at Cope Station were only required to be registered not permitted. As a result of this designation, Cope will need to restore the surface water equipment to operable status to reduce reliance on groundwater wells. This includes completion of 316(b) requirements, (including SCDHEC BACT determination and modification of the station national pollutant discharge elimination system permit) and extensive inspection, repair and/or replacement of the associated surface water withdrawal equipment which has been idle since 1996. While the impacts of this rule change are material to DESC’s results of operations, financial condition and/or cash flows, the existing regulatory framework in South Carolina provides rate recovery mechanisms that could substantially mitigate any such impacts for DESC.

 

Waste Management and Remediation

 

The operations of DESC are subject to a variety of state and federal laws and regulations governing the management and disposal of solid and hazardous waste, and release of hazardous substances associated with current and/or historical operations. The CERCLA, as amended, and similar state laws, may impose joint, several and strict liability for cleanup on potentially responsible parties who owned, operated or arranged for disposal at facilities affected by a release of hazardous substances. In addition, many states have created programs to incentivize voluntary remediation of sites where historical releases of hazardous substances are identified and property owners or responsible parties decide to initiate cleanups.

 

From time to time, DESC may be identified as a potentially responsible party in connection with the alleged release of hazardous substances or wastes at a site. Under applicable federal and state laws, DESC could be responsible for costs associated with the investigation or remediation of impacted sites, or subject to contribution claims by other responsible parties for their costs incurred at such sites. DESC also may identify, evaluate and remediate other potentially impacted sites under voluntary state programs. Remediation costs may be subject to reimbursement under DESC’s insurance policies, rate recovery mechanisms, or both. Except as described below, DESC does not believe these matters will have a material effect on results of operations, financial condition and/or cash flows.

 

DESC has four decommissioned MGP sites in South Carolina that are in various states of investigation, remediation and monitoring under work plans approved by, or under review by, the SCDHEC or the EPA. DESC anticipates that activities at these sites will continue through 2025 at an estimated cost of $9 million. In addition, for one site, an updated work plan submitted to SCDHEC in September 2018, would increase costs by approximately $11 million if approved by federal and state agencies. In September 2020, this plan was submitted to the Army Corps of Engineers. DESC expects to recover costs arising from the remediation work at all four sites through rate recovery mechanisms and as of June 30, 2021, deferred amounts, net of amounts previously recovered through rates and insurance settlements, totaled $22 million and are included in regulatory assets.

 

Ash Pond and Landfill Closure Costs

 

In April 2015, the EPA enacted a final rule regulating CCR landfills, existing ash ponds that still receive and manage CCRs, and inactive ash ponds that do not receive, but still store, CCRs. DESC currently has inactive and existing CCR ponds and CCR landfills subject to the final rule at 3 different facilities. This rule created a legal obligation for DESC to retrofit or close all of its inactive and existing ash ponds over a certain period of time, as well as perform required monitoring, corrective action, and post-closure care activities as necessary.

 

In December 2016, legislation was enacted that creates a framework for EPA- approved state CCR permit programs. In August 2017, the EPA issued interim guidance outlining the framework for state CCR program approval. The EPA has enforcement authority until state programs are approved. The EPA and states with approved programs both will have authority to enforce CCR requirements under their respective rules and programs. In September 2017, the EPA agreed to reconsider portions of the CCR rule in response to two petitions for reconsideration. In March 2018, the EPA proposed certain changes to the CCR rule related to issues remanded as part of the pending litigation and other issues the EPA is reconsidering. Several of the proposed changes would allow states with approved CCR permit programs additional flexibility in implementing their programs. In July 2018, the EPA promulgated the first phase of changes to the CCR rule. In August 2018, the U.S. Court of Appeals for the D.C. Circuit issued its decision in the pending challenges of the CCR rule, vacating and remanding to the EPA three provisions of the rule. Until this matter is resolved and all phases of the CCR rule are promulgated, DESC is unable to precisely estimate potential incremental impacts or costs related to existing coal ash sites in connection with future implementation of the final CCR rule. While such amounts may be material to DESC’s results of operations, financial condition and/or cash flows, the existing regulatory framework in South Carolina provides rate recovery mechanisms that could substantially mitigate any such impacts.

Abandoned NND Project

A description of events and circumstances leading up to DESC's abandonment of the NND Project and subsequent regulatory, legislative, legal and investigative proceedings, as well as related impairments of NND Project and other costs are described in Note 12 to the Consolidated Financial Statements in DESC's Annual Report on Form 10-K for the year ended December 31, 2020.

 

 

Claims and Litigation

The following describes certain legal proceedings involving DESC relating to events occurring before closing of the SCANA Combination. No reference to, or disclosure of, any proceeding, item or matter described below shall be construed as an admission or indication that such proceeding, item or matter is material. For certain of these matters, and unless otherwise noted therein, DESC is unable to estimate a reasonable range of possible loss and the related financial statement impacts, but for any such matter there could be a material impact to its results of operations, financial condition and/or cash flows. For the matters for which DESC is able to reasonably estimate, the Consolidated Balance Sheets at June 30, 2021 and December 31, 2020 include reserves of $278 million and $208 million, respectively, and insurance receivables of $23 million and $8 million, respectively, included within other receivables. During the three and six months ended June 30, 2021, DESC’s Consolidated Statements of Income include charges of $10 million ($8 million after-tax) and $70 million ($53 million after-tax), respectively, included within impairment of assets and other charges.

Ratepayer Class Actions

In May 2018, a consolidated complaint against DESC, SCANA and the State of South Carolina was filed in the State Court of Common Pleas in Hampton County, South Carolina (the DESC Ratepayer Case). The plaintiffs alleged, among other things, that DESC was negligent and unjustly enriched, breached alleged fiduciary and contractual duties and committed fraud and misrepresentation in failing to properly manage the NND Project, and that DESC committed unfair trade practices and violated state anti-trust laws. In December 2018, the State Court of Common Pleas in Hampton County entered an order granting preliminary approval of a class action settlement. The court entered an order granting final approval of the settlement in June 2019, which became effective in July 2019. The settlement agreement, contingent upon the closing of the SCANA Combination, provided that SCANA and DESC establish an escrow account and proceeds from the escrow account would be distributed to the plaintiffs, after payment of certain taxes, attorneys' fees and other expenses and administrative costs. The escrow account would include (1) up to $2.0 billion, net of a credit of up to $2.0 billion in future electric bill relief, which would inure to the benefit of the escrow account in favor of class members over a period of time established by the South Carolina Commission in its order related to matters before the South Carolina Commission related to the NND Project, (2) a cash payment of $115 million and (3) the transfer of certain DESC-owned real estate or sales proceeds from the sale of such properties, which counsel for the plaintiffs estimated to have an aggregate value between $60 million and $85 million. At the closing of the SCANA Combination, SCANA and DESC funded the cash payment portion of the escrow account. In July 2019, DESC transferred $117 million representing the cash payment, plus accrued interest, to the plaintiffs. Through August 2020, property, plant and equipment with a net recorded value of $22 million had been transferred to the plaintiffs in coordination with the court-appointed real estate trustee to satisfy the settlement agreement. In September 2020, the court entered an order approving a final resolution of the transfer of real estate or sales proceeds with a cash contribution of $38.5 million by DESC and the conveyance of property, plant and equipment with a net recorded value of $3 million, which was completed by DESC in October 2020.

In September 2017, a purported class action was filed by Santee Cooper ratepayers against Santee Cooper, DESC, Palmetto Electric Cooperative, Inc. and Central Electric Power Cooperative, Inc. in the State Court of Common Pleas in Hampton County, South Carolina (the Santee Cooper Ratepayer Case). The allegations were substantially similar to those in the DESC Ratepayer Case. In March 2020, the parties executed a settlement agreement relating to this matter as well as the Luquire Case and the Glibowski Case described below. The settlement agreement provided that Dominion Energy and Santee Cooper establish a fund for the benefit of class members in the amount of $520 million, of which Dominion Energy’s portion was $320 million of shares of Dominion Energy common stock. In July 2020, the court issued a final approval of the settlement agreement. In September 2020, Dominion Energy issued $322 million of shares of Dominion Energy common stock to satisfy its obligation under the settlement agreement, including interest charges.

In July 2019, a similar purported class action was filed by certain Santee Cooper ratepayers against DESC, SCANA, Dominion Energy and former directors and officers of SCANA in the State Court of Common Pleas in Orangeburg, South Carolina (the Luquire Case). In August 2019, DESC, SCANA and Dominion Energy were voluntarily dismissed from the case. The claims were similar to the Santee Cooper Ratepayer Case. In March 2020, the parties executed a settlement agreement as described above relating to this matter as well as the Santee Cooper Ratepayer Case and the Glibowski Case. This case was dismissed as part of the Santee Cooper Ratepayer Case settlement described above.

RICO Class Action

In January 2018, a purported class action was filed, and subsequently amended, against SCANA, DESC and certain former executive officers in the U.S. District Court for the District of South Carolina (the Glibowski Case). The plaintiff alleged, among other things, that SCANA, DESC and the individual defendants participated in an unlawful racketeering enterprise in violation of RICO and conspired to violate RICO by fraudulently inflating utility bills to generate unlawful proceeds. In March 2020, the parties executed a settlement agreement as described above relating to this matter as well as the Santee Cooper Ratepayer Case and the Luquire Case. This case was dismissed as part of the Santee Cooper Ratepayer Case settlement described above.

SCANA Shareholder Litigation

In February 2018, a purported class action was filed against Dominion Energy and certain former directors of SCANA and DESC in the State Court of Common Pleas in Richland County, South Carolina (the Metzler Lawsuit). The plaintiff alleges, among other

things, that defendants violated their fiduciary duties to shareholders by executing a merger agreement that would unfairly deprive plaintiffs of the true value of their SCANA stock, and that Dominion Energy aided and abetted these actions. Among other remedies, the plaintiff seeks to enjoin and/or rescind the merger. In February 2018, Dominion Energy removed the case to the U.S. District Court for the District of South Carolina and filed a Motion to Dismiss in March 2018. In September 2019, the U.S. District Court for the District of South Carolina granted the plaintiffs’ motion to consolidate the Metzler Lawsuit with another lawsuit regarding the SCANA Merger Agreement to which DESC is not a party. In October 2019, the plaintiffs filed an amended complaint against certain former directors and executive officers of SCANA and DESC, which stated substantially similar allegations to those in the initial lawsuits as well as an inseparable fraud claim. In November 2019, the defendants filed a motion to dismiss. In April 2020, the U.S. District Court for the District of South Carolina denied the motion to dismiss. In May 2020, SCANA filed a motion to intervene, which was denied in August 2020. In September 2020, SCANA filed a notice of appeal with the U.S. Court of Appeals for the Fourth Circuit. In June 2021, the parties reached an agreement in principle to settle this case, along with a related case to which DESC was not a party, subject to court approval, with no financial impact to DESC.

Employment Class Actions and Indemnification

In August 2017, a case was filed in the U.S. District Court for the District of South Carolina on behalf of persons who were formerly employed at the NND Project. In July 2018, the court certified this case as a class action. In February 2019, certain of these plaintiffs filed an additional case, which case has been dismissed and the plaintiffs have joined the case filed August 2017. The plaintiffs allege, among other things, that SCANA, DESC, Fluor Corporation and Fluor Enterprises, Inc. violated the Worker Adjustment and Retraining Notification Act in connection with the decision to stop construction at the NND Project. The plaintiffs allege that the defendants failed to provide adequate advance written notice of their terminations of employment and are seeking damages, which could be as much as $100 million for 100% of the NND Project. In January 2021, the U.S. District Court for the District of South Carolina granted summary judgment in favor of SCANA, DESC, Fluor Corporation and Fluor Enterprises, Inc. In February 2021, the plaintiffs filed a notice of appeal with the U.S. Court of Appeals for the Fourth Circuit. This case is pending.

In September 2018, a case was filed in the State Court of Common Pleas in Fairfield County, South Carolina by Fluor Enterprises, Inc. and Fluor Daniel Maintenance Services, Inc. against DESC and Santee Cooper. The plaintiffs make claims for indemnification, breach of contract and promissory estoppel arising from, among other things, the defendants' alleged failure and refusal to defend and indemnify the Fluor defendants in the aforementioned case. This case is pending.

FILOT Litigation and Related Matters

In November 2017, Fairfield County filed a complaint and a motion for temporary injunction against DESC in the State Court of Common Pleas in Fairfield County, South Carolina, making allegations of breach of contract, fraud, negligent misrepresentation, breach of fiduciary duty, breach of implied duty of good faith and fair dealing and unfair trade practices related to DESC’s termination of the FILOT agreement between DESC and Fairfield County related to the NND Project. The plaintiff sought a temporary and permanent injunction to prevent DESC from terminating the FILOT agreement. The plaintiff withdrew the motion for temporary injunction in December 2017. In July 2021, the parties executed a settlement agreement requiring DESC to pay $99 million, which could be satisfied in either cash or shares of Dominion Energy common stock. Also in July 2021, the State Court of Common Pleas in Fairfield County, South Carolina approved the settlement. In July 2021, Dominion Energy issued 1.4 million shares of Dominion Energy common stock to satisfy DESC’s obligation under the settlement agreement.

Governmental Proceedings and Investigations

In June 2018, DESC received a notice of proposed assessment of approximately $410 million, excluding interest, from the SCDOR following its audit of DESC’s sales and use tax returns for the periods September 1, 2008 through December 31, 2017. The proposed assessment, which includes 100% of the NND Project, is based on the SCDOR’s position that DESC’s sales and use tax exemption for the NND Project does not apply because the facility will not become operational. In December 2020, the parties reached an agreement in principle in the amount of $165 million to resolve this matter. In June 2021, the parties executed a settlement agreement which allows DESC to fund the settlement amount through a combination of cash, shares of Dominion Energy common stock or real estate with an initial payment of at least $43 million in shares of Dominion Energy common stock. In August 2021, Dominion Energy issued 0.6 million shares of its common stock to satisfy DESC’s obligation for the initial payment under the settlement agreement.

In September and October 2017, SCANA was served with subpoenas issued by the U.S. Attorney’s Office for the District of South Carolina and the Staff of the SEC’s Division of Enforcement seeking documents related to the NND Project. In February 2020, the SEC filed a complaint against SCANA, two of its former executive officers and DESC in the U.S. District Court for the District of South Carolina alleging that the defendants violated federal securities laws by making false and misleading statements about the NND Project. In April 2020, SCANA and DESC reached an agreement in principle with the Staff of the SEC’s Division of Enforcement to settle, without admitting or denying the allegations in the complaint. In December 2020, the U.S. District Court for the District of South Carolina issued an order approving the settlement which required SCANA to pay a civil monetary penalty totaling $25 million, and SCANA and DESC to pay disgorgement and prejudgment interest totaling $112.5 million, which disgorgement and prejudgment interest amount were deemed satisfied by the settlements in the SCANA Securities Class Action and the DESC Ratepayer Case.

SCANA paid the civil penalty in December 2020. The SEC civil action against two former executive officers of SCANA remains pending and is currently subject to a stay granted by the court in June 2020 at the request of the U.S. Attorney’s Office for the District of South Carolina.

In addition, the South Carolina Law Enforcement Division is conducting a criminal investigation into the handling of the NND Project by SCANA and DESC. Dominion Energy is cooperating fully with the investigations by the U.S. Attorney’s Office and the South Carolina Law Enforcement Division, including responding to additional subpoenas and document requests. Dominion Energy has also entered into a cooperation agreement with the U.S. Attorney’s Office and the South Carolina Attorney General’s Office. The cooperation agreement provides that in consideration of its full cooperation with these investigations to the satisfaction of both agencies, neither such agency will criminally prosecute or bring any civil action against Dominion Energy or any of its current, previous, or future direct or indirect subsidiaries related to the NND Project. A former executive officer of SCANA entered a plea agreement with the U.S. Attorney’s Office and the South Carolina Attorney General’s Office in June 2020 and entered a guilty plea with the U.S. District Court for the District of South Carolina in July 2020. Another former executive officer of SCANA entered a plea agreement with the U.S. Attorney's Office and the South Carolina Attorney General's Office in November 2020 and entered guilty pleas in the U.S. District Court for the District of South Carolina and in South Carolina state court in February 2021. As a result of the pleas, Dominion Energy has terminated indemnity for these former executive officers related to these two cases.

Other Litigation

In September 2019, a South Carolina state court jury awarded a judgment to the estate of Jose Larios in a wrongful death suit filed in June 2017 against DESC, of which DESC was apportioned $19 million. DESC holds general liability insurance coverage which is expected to provide payment for substantially all DESC’s liability in this matter. In October 2019, DESC filed a motion requesting a reduction in the judgment or, in the alternative, a new trial. In November 2019, DESC’s motion for a new trial was granted, setting aside the entire verdict amount. This matter is pending.

Contractor Bankruptcy Proceedings

Westinghouse’s Reorganization Plan became effective August 1, 2018. Initially, Westinghouse had projected that its Reorganization Plan would pay in full or nearly in full its pre-petition trade creditors, including several of the Westinghouse Subcontractors which have alleged non-payment by the Consortium for amounts owed for work performed on the NND Project and have filed liens on related property in Fairfield County, South Carolina. DESC is contesting approximately $285 million of such filed liens. Most of these asserted liens are “pre-petition” claims that relate to work performed by Westinghouse Subcontractors before the Westinghouse bankruptcy, although some of them are “post-petition” claims arising from work performed after the Westinghouse bankruptcy. It is possible that the Reorganization Plan will not provide for payment in full or nearly in full to its pre-petition trade creditors. The shortfall could be significant. In addition, payments under the Toshiba Settlement are subject to reduction if Westinghouse pays Westinghouse Subcontractors holding pre-petition liens directly. Under these circumstances, DESC and Santee Cooper, each in its pro rata share, would be required to make Citibank, N.A., which purchased the scheduled payments under the Toshiba Settlement, whole for reductions related to valid subcontractor and vendor pre-petition liens up to $60 million ($33 million for DESC's 55% share).

DESC and Santee Cooper were responsible for amounts owed to Westinghouse for valid work performed by Westinghouse Subcontractors on the NND Project after the Westinghouse bankruptcy filing (i.e., post-petition) until termination of the IAA (the IAA Period). In the Westinghouse bankruptcy proceeding, deadlines were established for creditors of Westinghouse to assert the amounts owed to such creditors prior to the Westinghouse bankruptcy filing and during the IAA Period. Many of the Westinghouse Subcontractors have filed such claims. In December 2019, DESC and Santee Cooper entered into a confidential settlement agreement with W Wind Down Co LLC resolving claims relating to the IAA.

Further, some Westinghouse Subcontractors who have made claims against Westinghouse in the bankruptcy proceeding also filed against DESC and Santee Cooper in South Carolina state court for damages. The Westinghouse Subcontractor claims in South Carolina state court include common law claims for pre-petition work, IAA Period work, and work after the termination of the IAA. Many of these claimants have also asserted construction liens against the NND Project site. While DESC cannot be assured that it will not have any exposure on account of unpaid Westinghouse Subcontractor claims, which claims DESC is presently disputing, DESC believes it is unlikely that it will be required to make payments on account of such claims that would exceed the portion of the Toshiba Settlement allocated for such balances within the SCANA Merger Approval Order recorded in regulatory liabilities on DESC’s Consolidated Balance Sheets.

Nuclear Insurance

Other than the item discussed below, there have been no significant changes regarding DESC’s nuclear insurance as described in Note 12 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020.

In March 2021, the total liability protection per nuclear incident available to all participants in the Secondary Financial Protection Program decreased from $13.8 billion to $13.7 billion. In June 2021, the total liability protection per nuclear incident available to all

participants in the Secondary Financial Protection Program decreased from $13.7 billion to $13.5 billion. These decreases do not impact DESC’s responsibility per active unit under the Price-Anderson Amendments Act of 1988.
v3.21.2
Operating Segments
 6 Months Ended
Jun. 30, 2021
Segment Reporting [Abstract]  
Operating Segments

11. OPERATING SEGMENTS

The Corporate and Other segment includes specific items attributable to its operating segment that are not included in profit measures evaluated by executive management in assessing the segment’s performance or in allocating resources.

In the six months ended June 30, 2021, DESC reported after-tax net expense of $256 million for specific items in the Corporate and Other segment, all of which was attributable to its operating segment. In the six months ended June 30, 2020, DESC reported after-tax net expense of $7 million for specific items in the Corporate and Other segment, all of which was attributable to its operating segment.

The net expense for specific items attributable to DESC’s operating segment in 2021 primarily related to the impact of the following items:

•

$266 million ($199 million after-tax) of charges associated with the settlement of the South Carolina electric base rate case; and

•

A $70 million ($53 million after-tax) charge associated with litigation.

 

(millions)

 

External

Revenue

 

 

Comprehensive

Income (Loss)

Available

(Attributable) to

Common

Shareholder

 

Three Months Ended June 30, 2021

 

 

 

 

 

 

 

 

Dominion Energy South Carolina

 

$

692

 

 

$

79

 

Corporate and Other

 

 

—

 

 

 

(210

)

Consolidated Total

 

$

692

 

 

$

(131

)

 

 

 

 

 

 

 

 

 

Three Months Ended June 30, 2020

 

 

 

 

 

 

 

 

Dominion Energy South Carolina

 

$

624

 

 

$

77

 

Corporate and Other

 

 

—

 

 

 

(8

)

Consolidated Total

 

$

624

 

 

$

69

 

 

 

 

 

 

 

 

 

 

Six Months Ended June 30, 2021

 

 

 

 

 

 

 

 

Dominion Energy South Carolina

 

$

1,436

 

 

$

176

 

Corporate and Other

 

 

—

 

 

 

(256

)

Consolidated Total

 

$

1,436

 

 

$

(80

)

 

 

 

 

 

 

 

 

 

Six Months Ended June 30, 2020

 

 

 

 

 

 

 

 

Dominion Energy South Carolina

 

$

1,296

 

 

$

166

 

Corporate and Other

 

 

—

 

 

 

(9

)

Consolidated Total

 

$

1,296

 

 

$

157

 

 
v3.21.2
Affiliated and Related Party Transactions
 6 Months Ended
Jun. 30, 2021
Related Party Transactions [Abstract]  
Affiliated and Related Party Transactions

12. AFFILIATED AND RELATED PARTY TRANSACTIONS

DESC owns 40% of Canadys Refined Coal, LLC, which is involved in the manufacturing and sale of refined coal to reduce emissions at one of DESC's generating facilities. DESC accounts for this investment using the equity method.

DESS, on behalf of itself and its parent company, provided the following services to DESC through December 2020, which were rendered at direct or allocated cost: information systems, telecommunications, customer support, marketing and sales, human resources, corporate compliance, purchasing, financial, risk management, public affairs, legal, investor relations, gas supply and capacity management, strategic planning, general administrative and retirement benefits. In addition, DESS processed and paid invoices for DESC and was reimbursed. Effective January 2021, DES provides to DESC the services previously provided by DESS. Costs for these services include amounts capitalized. Amounts expensed are primarily recorded in other operations and maintenance - affiliated suppliers and other income (expense), net in the Consolidated Statements of Comprehensive Income (Loss).

 

 

 

Three Months Ended

June 30,

 

 

Six Months Ended

June 30,

 

(millions)

 

2021

 

 

2020

 

 

2021

 

 

2020

 

Direct and allocated costs from DES and DESS(1)

 

$

57

 

 

$

63

 

 

$

115

 

 

$

130

 

Operating Revenues - Electric from sales to affiliate

 

 

1

 

 

 

2

 

 

 

2

 

 

 

2

 

Operating Expenses - Other taxes from affiliate

 

 

2

 

 

 

1

 

 

 

4

 

 

 

4

 

Purchases of electricity from solar affiliates

 

 

5

 

 

 

4

 

 

 

7

 

 

 

6

 

Demand and transportation charges from DECG - Fuel used in

   electric generation

 

 

—

 

 

 

5

 

 

 

—

 

 

 

9

 

Demand and transportation charges from DECG - Gas purchased

   for resale

 

 

—

 

 

 

11

 

 

 

—

 

 

 

22

 

 

(1)

Includes capitalized expenditures of $10 million and $13 million for the three months ended June 30, 2021 and 2020, respectively, and $15 million and $25 million for the six months ended June 30, 2021 and 2020, respectively.

 

(millions)

 

June 30, 2021

 

 

December 31, 2020

 

Payable to DES and DESS

 

$

1

 

 

$

59

 

Receivable from DES

 

 

2

 

 

 

—

 

Payable to Public Service Company of North Carolina, Incorporated

 

 

13

 

 

 

5

 

Payable to solar affiliates

 

 

2

 

 

 

1

 

Derivative assets with affiliates(1)

 

 

3

 

 

 

—

 

Derivative liabilities with affiliates(1)

 

 

7

 

 

 

—

 

 

(1)

Effective in the second quarter of 2021, contracts for the future purchase of certain quantities of electricity from solar affiliates no longer met the criteria for the normal purchase normal sale exception and are accounted for as derivative contracts.

 

Borrowings from an affiliate are described in Note 5.
v3.21.2
Other Income (Expense), Net
 6 Months Ended
Jun. 30, 2021
Income Statement [Abstract]  
Other Income (Expense), Net

13. OTHER INCOME (EXPENSE), NET

Components of other income (expense), net are as follows:

 

 

 

Three Months Ended

June 30,

 

 

Six Months Ended

June 30,

 

(millions)

 

2021

 

 

2020

 

 

2021

 

 

2020

 

Revenues from contracts with customers

 

$

—

 

 

$

—

 

 

$

—

 

 

$

1

 

Other income

 

 

4

 

 

 

4

 

 

 

7

 

 

 

7

 

Other expense

 

 

(18

)

 

 

(3

)

 

 

(16

)

 

 

(5

)

Allowance for equity funds used during construction

 

 

2

 

 

 

1

 

 

 

3

 

 

 

2

 

Other income (expense), net

 

$

(12

)

 

$

2

 

 

$

(6

)

 

$

5

 

 

Non-service cost components of pension and other postretirement benefits are included in other income (expense).
v3.21.2
Summary of Significant Accounting Policies (Policies)
 6 Months Ended
Jun. 30, 2021
Accounting Policies [Abstract]  
Basis of Consolidation and Variable Interest Entities

Basis of Consolidation and Variable Interest Entities

DESC has determined that it has a controlling financial interest in each of GENCO and Fuel Company (which are considered to be VIEs) and, accordingly, DESC's Consolidated Financial Statements include, after eliminating intercompany balances and transactions, the accounts of DESC, GENCO and Fuel Company. See Note 2 to the Consolidated Financial Statements included in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020 for a description of GENCO and Fuel Company.

Effective January 2021, DESC purchases shared services from DES, an affiliated VIE that provides accounting, legal, finance and certain administrative and technical services to all Dominion Energy subsidiaries, including DESC. DESC had previously purchased such services from DESS, an affiliated VIE, that had provided such services to all SCANA subsidiaries. DESC has determined that it is not the primary beneficiary of DES as it does not have either the power to direct the activities that most significantly impact its economic performance or an obligation to absorb losses and benefits which could be significant to it. See Note 12 for amounts attributable to affiliates.

Significant Accounting Policies

There have been no significant changes from Note 2 to the Consolidated Financial Statements in DESC's Annual Report on Form 10-K for the year ended December 31, 2020.
v3.21.2
Rate and Other Regulatory Matters (Tables)
 6 Months Ended
Jun. 30, 2021
Regulated Operations [Abstract]  
Schedule of Regulatory Assets and Liabilities

 

 

 

June 30,

 

 

December 31,

 

(millions)

 

2021

 

 

2020

 

Regulatory assets:

 

 

 

 

 

 

 

 

NND Project costs(1)

 

$

138

 

 

$

138

 

Deferred employee benefit plan costs(2)

 

 

8

 

 

 

9

 

Other unrecovered plant(3)

 

 

15

 

 

 

14

 

DSM programs(4)

 

 

23

 

 

 

29

 

AROs(5)

 

 

2

 

 

 

2

 

Cost of fuel and purchased gas under-collections(6)

 

 

—

 

 

 

1

 

Other

 

 

26

 

 

 

36

 

Regulatory assets - current

 

 

212

 

 

 

229

 

NND Project costs(1)

 

 

2,295

 

 

 

2,364

 

AROs(5)

 

 

311

 

 

 

309

 

Cost of reacquired debt(7)

 

 

11

 

 

 

243

 

Deferred employee benefit plan costs(2)

 

 

156

 

 

 

159

 

Deferred losses on interest rate derivatives(8)

 

 

300

 

 

 

308

 

Other unrecovered plant(3)

 

 

59

 

 

 

61

 

DSM programs(4)

 

 

46

 

 

 

46

 

Environmental remediation costs(9)

 

 

20

 

 

 

20

 

Deferred storm damage costs(10)

 

 

45

 

 

 

45

 

Deferred transmission operating costs(11)

 

 

76

 

 

 

63

 

Other(12)

 

 

141

 

 

 

108

 

Regulatory assets - noncurrent

 

 

3,460

 

 

 

3,726

 

Total regulatory assets

 

$

3,672

 

 

$

3,955

 

Regulatory liabilities:

 

 

 

 

 

 

 

 

Monetization of guaranty settlement(13)

 

$

67

 

 

$

67

 

Income taxes refundable through future rates(14)

 

 

36

 

 

 

21

 

Reserve for refunds to electric utility customers(15)

 

 

123

 

 

 

128

 

Cost of fuel and purchased gas over-collections(6)

 

 

38

 

 

 

58

 

Other

 

 

21

 

 

 

9

 

Regulatory liabilities - current

 

 

285

 

 

 

283

 

Monetization of guaranty settlement(13)

 

 

869

 

 

 

903

 

Income taxes refundable through future rates(14)

 

 

893

 

 

 

919

 

Asset removal costs(16)

 

 

572

 

 

 

564

 

Deferred gains on interest rate derivatives(8)

 

 

68

 

 

 

69

 

Reserve for refunds to electric utility customers(15)

 

 

475

 

 

 

540

 

Other

 

 

24

 

 

 

10

 

Regulatory liabilities - noncurrent

 

 

2,901

 

 

 

3,005

 

Total regulatory liabilities

 

$

3,186

 

 

$

3,288

 

 

(1)

Reflects expenditures associated with the NND Project, which pursuant to the SCANA Merger Approval Order, will be recovered from electric service customers over a 20-year period ending in 2039. See Note 10 for more information.

(2)

Employee benefit plan costs have historically been recovered as they have been recorded under GAAP. Deferred employee benefit plan costs represent amounts of pension and other postretirement benefit costs which were accrued as liabilities and treated as regulatory assets pursuant to FERC guidance, and costs deferred pursuant to specific South Carolina Commission regulatory orders. DESC expects to recover deferred pension costs through utility rates over periods through 2044. DESC expects to recover other deferred benefit costs through utility rates, primarily over average service periods of participating employees up to 11 years.

(3)

Represents the carrying value of coal-fired generating units, including related materials and supplies inventory, retired from service prior to being fully depreciated. DESC is amortizing these amounts through cost of service rates following deprecation amounts that were designed to recover the retired units’ cost over their previous estimated remaining useful lives, which has been estimated to be through 2025. Based on

current projections of remaining decommissioning costs, projected recovery is expected to extend to 2028. Unamortized amounts are included in rate base and are earning a current return.

(4)

Represents deferred costs associated with electric demand reduction programs, and such deferred costs are currently being recovered over three years through an approved rate rider.

(5)

Represents deferred depreciation and accretion expense related to legal obligations associated with the future retirement of generation, transmission and distribution properties. The AROs primarily relate to DESC’s electric generating facilities, including Summer, and are expected to be recovered over the related property lives and periods of decommissioning which may range up to approximately 105 years.

(6)

Represents amounts under- or over-collected from customers pursuant to the cost of fuel and purchased gas components approved by the South Carolina Commission.

(7)

During the second quarter of 2021, DESC recorded a charge of $237 million ($178 million after-tax) in impairment of assets and other charges to write-off the balance of a regulatory asset that is no longer probable of recovery under the settlement agreement approved in DESC’s retail electric base rate case. See South Carolina Electric Base Rate Case discussed above for more information.

(8)

Represents (i) the changes in fair value and payments made or received upon settlement of certain interest rate derivatives designated as cash flow hedges and (ii) the changes in fair value and payments made or received upon settlement of certain other interest rate derivatives not so designated. The amounts recorded with respect to (i) are expected to be amortized to interest expense over the lives of the underlying debt through 2043.The amounts recorded with respect to (ii) are expected to be similarly amortized to interest expense through 2065.

(9)

Reflects amounts associated with the assessment and clean-up of sites currently or formerly owned by DESC. Such remediation costs are expected to be recovered over periods of up to 15 years. See Note 10 for more information.

(10)

Represents storm restoration costs for which DESC expects to recover through customer rates over approximately 10 years pursuant to the settlement agreement approved in DESC’s retail electric base rate case.

(11)

Includes deferred depreciation and property taxes associated with certain transmission assets for which DESC expects to recover from customers over approximately 40 years pursuant to the settlement agreement approved in DESC’s retail electric base rate case.

(12)

Various other regulatory assets are expected to be recovered through rates over varying periods through 2047.

(13)

Represents proceeds related to the monetization of the Toshiba Settlement. In accordance with the SCANA Merger Approval Order, this balance, net of amounts that may be required to satisfy liens, will be refunded to electric customers over a 20-year period ending in 2039. See Note 12 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020.

(14)

Includes (i) excess deferred income taxes arising from the remeasurement of deferred income taxes in connection with the enactment of the 2017 Tax Reform Act (certain of which are protected under normalization rules and will be amortized over the remaining lives of related property, and certain of which will be amortized to the benefit of customers over prescribed periods as instructed by regulators) and (ii) deferred income taxes arising from investment tax credits, offset by (iii) deferred income taxes that arise from utility operations that have not been included in customer rates (a portion of which relate to depreciation and are expected to be recovered over the remaining lives of the related property which may range up to 85 years). See Note 6 for more information.

(15)

Reflects amounts previously collected from retail electric customers of DESC for the NND Project to be credited to customers over an estimated 11-year period effective February 2019 in connection with the SCANA Merger Approval Order. See Note 12 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020.

(16)

Represents estimated net collections through depreciation rates of amounts to be expended for the removal of assets in the future.
v3.21.2
Revenue Recognition (Tables)
 6 Months Ended
Jun. 30, 2021
Revenue From Contract With Customer [Abstract]  
Disaggregation of Revenue

DESC has disaggregated operating revenues by customer class as follows:

 

 

 

Three Months Ended

 

 

Three Months Ended

 

 

Six Months Ended

 

 

Six Months Ended

 

 

 

June 30, 2021

 

 

June 30, 2020

 

 

June 30, 2021

 

 

June 30, 2020

 

(millions)

 

Electric

 

 

Gas

 

 

Electric

 

 

Gas

 

 

Electric

 

 

Gas

 

 

Electric

 

 

Gas

 

Customer class:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Residential

 

$

271

 

 

$

38

 

 

$

261

 

 

$

33

 

 

$

546

 

 

$

136

 

 

$

513

 

 

$

112

 

Commercial

 

 

199

 

 

 

26

 

 

 

177

 

 

 

20

 

 

 

374

 

 

 

65

 

 

 

352

 

 

 

53

 

Industrial

 

 

95

 

 

 

18

 

 

 

83

 

 

 

12

 

 

 

183

 

 

 

40

 

 

 

163

 

 

 

29

 

Other

 

 

38

 

 

 

7

 

 

 

27

 

 

 

4

 

 

 

71

 

 

 

12

 

 

 

57

 

 

 

8

 

Revenues from contracts with

   customers

 

 

603

 

 

 

89

 

 

 

548

 

 

 

69

 

 

 

1,174

 

 

 

253

 

 

 

1,085

 

 

 

202

 

Other revenues

 

 

—

 

 

 

—

 

 

 

7

 

 

 

—

 

 

 

8

 

 

 

1

 

 

 

9

 

 

 

—

 

Total Operating Revenues

 

$

603

 

 

$

89

 

 

$

555

 

 

$

69

 

 

$

1,182

 

 

$

254

 

 

$

1,094

 

 

$

202

 
v3.21.2
Long-Term and Short-Term Debt (Tables)
 6 Months Ended
Jun. 30, 2021
Debt Disclosure [Abstract]  
Schedule of Line of Credit Facilities

At June 30, 2021, DESC's share of commercial paper and letters of credit outstanding under its joint credit facility with Dominion Energy, was as follows:

 

(millions)

 

Facility Limit

 

 

Outstanding

Commercial Paper

 

 

Outstanding

Letters of Credit

 

Joint revolving credit facility(1)

 

$

1,000

 

 

$

60

 

 

$

—

 

 

(1)

A maximum of $1.0 billion of the facility is available to DESC, assuming adequate capacity is available after giving effect to uses by co-borrowers Dominion Energy, Virginia Power and Questar Gas. The sub-limit for DESC is set within the facility limit but can be changed at the option of the co-borrowers multiple times per year. At June 30, 2021, the sub-limit for DESC was $500 million. If DESC has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from DESC's parent or from Dominion Energy. This credit facility matures in June 2026, with the potential to be extended by the borrowers to June 2028. The credit facility can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $1.0 billion (or the sub-limit, whichever is less) of letters of credit.

v3.21.2
Derivative Financial Instruments (Tables)
 6 Months Ended
Jun. 30, 2021
Derivative Instruments And Hedging Activities Disclosure [Abstract]  
Offsetting Liabilities

The table below presents derivative balances by type of financial instrument, if the gross amounts recognized in the Consolidated Balance Sheets were netted with derivative instruments and cash collateral received or paid. DESC’s commodity derivative assets are not subject to a master netting agreement or similar arrangement.

 

 

 

June 30, 2021

 

 

December 31, 2020

 

 

 

Gross Amounts Not Offset in the Consolidated

Balance Sheet

 

 

Gross Amounts Not Offset in the Consolidated

Balance Sheet

 

(millions)

 

Gross

Liabilities

Presented in the

Consolidated

Balance Sheet(1)

 

 

Financial

Instruments

 

 

Cash

Collateral

Paid

 

 

Net

Amounts

 

 

Gross

Liabilities

Presented in the

Consolidated

Balance Sheet(1)

 

 

Financial

Instruments

 

 

Cash

Collateral

Paid

 

 

Net

Amounts

 

Interest rate contracts:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Over-the-counter

 

$

22

 

 

$

—

 

 

$

11

 

 

$

11

 

 

$

27

 

 

$

—

 

 

$

17

 

 

$

10

 

Total derivatives

 

$

22

 

 

$

—

 

 

$

11

 

 

$

11

 

 

$

27

 

 

$

—

 

 

$

17

 

 

$

10

 

1) Excludes $28 million and $— million of derivative liabilities at June 30, 2021 and December 31, 2020, respectively, which are not subject to master netting or similar arrangements.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
Schedule of Volume of Derivative Activity

The following table presents the volume of derivative activity at June 30, 2021. These volumes are based on open derivative positions and represent the combined absolute value of their long and short positions.

 

 

Current

 

 

Noncurrent

 

Electricity (MWh):

 

 

 

 

 

 

 

 

Fixed price

 

 

1,642,960

 

 

 

23,508,146

 

Interest rate(1) (millions)

 

$

—

 

 

$

71

 

(1)

Maturity is determined based on final settlement period.
Fair Value of Derivatives

The following tables present the fair values of derivatives and where they are presented in the Consolidated Balance Sheets:

 

(millions)

 

Fair Value -

Derivatives

under Hedge

Accounting

 

 

Fair Value -

Derivatives not

under Hedge

Accounting

 

 

Total Fair Value

 

At June 30, 2021

 

 

 

 

 

 

 

 

 

 

 

 

ASSETS

 

 

 

 

 

 

 

 

 

 

 

 

Current Assets

 

 

 

 

 

 

 

 

 

 

 

 

Commodity

 

$

—

 

 

$

5

 

 

$

5

 

Total current derivative assets(1)

 

 

—

 

 

 

5

 

 

 

5

 

Noncurrent Assets

 

 

 

 

 

 

 

 

 

 

 

 

Commodity

 

 

—

 

 

 

10

 

 

 

10

 

Total noncurrent derivative assets(2)

 

 

—

 

 

 

10

 

 

 

10

 

Total derivative assets

 

$

—

 

 

$

15

 

 

$

15

 

LIABILITIES

 

 

 

 

 

 

 

 

 

 

 

 

Current Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

Interest rate

 

$

1

 

 

$

1

 

 

$

2

 

Total current derivative liabilities(3)

 

 

1

 

 

 

1

 

 

 

2

 

Noncurrent Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

Commodity

 

 

—

 

 

 

28

 

 

 

28

 

Interest rate

 

 

12

 

 

 

8

 

 

 

20

 

Total noncurrent derivative liabilities(4)

 

 

12

 

 

 

36

 

 

 

48

 

Total derivative liabilities

 

$

13

 

 

$

37

 

 

$

50

 

At December 31, 2020

 

 

 

 

 

 

 

 

 

 

 

 

LIABILITIES

 

 

 

 

 

 

 

 

 

 

 

 

Current Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

Interest rate

 

$

1

 

 

$

1

 

 

$

2

 

Total current derivative liabilities(3)

 

 

1

 

 

 

1

 

 

 

2

 

Noncurrent Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

Interest rate

 

 

15

 

 

 

10

 

 

 

25

 

Total noncurrent derivative liabilities(4)

 

 

15

 

 

 

10

 

 

 

25

 

Total derivative liabilities

 

$

16

 

 

$

11

 

 

$

27

 

 

(1)

Current derivative assets are presented in other current assets in the Consolidated Balance Sheets.

(2)

Noncurrent derivative assets are presented in other deferred debits and other assets in the Consolidated Balance Sheets.

(3)

Current derivative liabilities are presented in other current liabilities in the Consolidated Balance Sheets.

(4)

Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in the Consolidated Balance Sheets.
Derivatives in Cash Flow Hedging Relationships

The following tables present the gains and losses on derivatives, as well as where the associated activity is presented in the Consolidated Balance Sheets and Statements of Comprehensive Income (Loss):

Derivatives in Cash Flow Hedging Relationships

 

(millions)

Increase (Decrease)

in Derivatives

Subject to

Regulatory

Treatment(1)

 

Three Months Ended June 30, 2021

 

 

 

Derivative type and location of gains (losses):

 

 

 

Interest rate

$

(1

)

Total

$

(1

)

Three Months Ended June 30, 2020

 

 

 

Derivative type and location of gains (losses):

 

 

 

Interest rate

$

2

 

Total

$

2

 

Six Months Ended June 30, 2021

 

 

 

Derivative type and location of gains (losses):

 

 

 

Interest rate

$

6

 

Total

$

6

 

Six Months Ended June 30, 2020

 

 

 

Derivative type and location of gains (losses):

 

 

 

Interest rate

$

(4

)

Total

$

(4

)

 

(1)

Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/ liabilities have no associated effect in the Consolidated Statements of Comprehensive Income (Loss).

Derivatives Not Designated as Hedging Instruments

Derivatives Not Designated as Hedging Instrument

There were no gains and losses on derivatives not designated as hedging instruments for both the three months ended June 30, 2021 and June 30, 2020.

(millions)

 

 

 

Amount of Gain (Loss)

Recognized in Income on

Derivatives(1)

 

Six Months Ended June 30,

 

Location

 

2021

 

 

2020

 

Derivative type and location of gains (losses):

 

 

 

 

 

 

 

 

 

 

Interest rate contracts:

 

Interest charges

 

$

(1

)

 

$

—

 

Total interest rate contracts

 

 

 

$

(1

)

 

$

—

 

(1)

Includes derivative activity amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in the Consolidated Statements of Comprehensive Income (Loss).
v3.21.2
Fair Value Measurements, Including Derivatives (Tables)
 6 Months Ended
Jun. 30, 2021
Fair Value Disclosures [Abstract]  
Schedule of Quantitative Information About Level 3 Fair Value Measurements

The following table presents DESC’s quantitative information about Level 3 fair value measurements at June 30, 2021. The range and weighted average are presented in dollars for market price inputs.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fair Value

(millions)

 

 

Valuation Techniques

 

Unobservable Input

 

 

Range

 

Weighted

Average(1)

 

Assets

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Physical forwards:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Electricity

 

$

15

 

 

Discounted cash flow

 

Market price (per MWh)

(2)

 

23 - 54

 

 

35

 

Total assets

 

$

15

 

 

 

 

 

 

 

 

 

 

 

 

Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Physical forwards:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Electricity

 

$

28

 

 

Discounted cash flow

 

Market price (per MWh)

(2)

 

23 - 55

 

 

35

 

Total liabilities

 

$

28

 

 

 

 

 

 

 

 

 

 

 

 

(1)   Averages weighted by volume.

(2)Represents market prices beyond defined terms for Levels 1 and 2.

 
Schedule of Sensitivity of The Fair Value Measurements To Changes in The Significant Unobservable Inputs

Sensitivity of the fair value measurements to changes in the significant unobservable inputs is as follows:

 

Significant Unobservable

Inputs

 

Position

 

Change to Input

 

Impact on Fair Value

Measurement

Market price

 

Buy

 

Increase (decrease)

 

Gain (loss)

Market price

 

Sell

 

Increase (decrease)

 

Loss (gain)
Schedule of Liabilities Measured at Fair Value on Recurring Basis

The following table presents DESC’s liabilities that are measured at fair value on a recurring basis for each hierarchy level, including both current and noncurrent portions:

 

(millions)

 

Level 1

 

 

Level 2

 

 

Level 3

 

 

Total

 

At June 30, 2021

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Assets

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Commodity

 

$

—

 

 

$

—

 

 

$

15

 

 

$

15

 

Total assets

 

$

—

 

 

$

—

 

 

$

15

 

 

$

15

 

Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Commodity

 

$

—

 

 

$

—

 

 

$

28

 

 

$

28

 

Interest rate

 

 

—

 

 

 

22

 

 

 

—

 

 

 

22

 

Total liabilities

 

$

—

 

 

$

22

 

 

$

28

 

 

$

50

 

At December 31, 2020

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Liabilities

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Interest rate

 

$

—

 

 

$

27

 

 

$

—

 

 

$

27

 

Total liabilities

 

$

—

 

 

$

27

 

 

$

—

 

 

$

27

 
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table presents the net change in DESC's assets and liabilities measured at fair value on a recurring basis and included in the Level 3 fair value category. There were no net changes in assets and liabilities measured at fair value on a recurring basis and included in the Level 3 fair value category for the three and six months ended June 30, 2020.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Three Months Ended

Six Months Ended

 

 

 

June 30,

June 30,

 

 

 

2021

 

 

2021

 

(millions)

 

 

 

 

 

 

 

 

Beginning balance

 

$

—

 

 

$

—

 

Total realized and unrealized losses:

 

 

 

 

 

 

 

 

Included in regulatory assets/liabilities

 

 

(13

)

 

 

(13

)

Ending balance

 

$

(13

)

 

$

(13

)

 

There were no unrealized gains or losses included in earnings in the Level 3 fair value category relating to assets/liabilities still held atthe reporting date for the three and six months ended June 30, 2021.

 
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments For financial instruments that are not recorded at fair value, the carrying amounts and estimated fair values are as follows:

 

 

 

June 30, 2021

 

 

December 31, 2020

 

(millions)

 

Carrying

Amount

 

 

Estimated

Fair Value(1)

 

 

Carrying

Amount

 

 

Estimated

Fair Value(1)

 

Long-term debt(2)

 

$

3,360

 

 

$

4,515

 

 

$

3,360

 

 

$

4,748

 

Affiliated long-term debt

 

 

230

 

 

 

230

 

 

 

230

 

 

 

230

 

 

(1)

Fair value is estimated using market prices, where available, and interest rates currently available for issuance of debt with similar terms and remaining maturities. All fair value measurements are classified as Level 2. The carrying amount of debt issuances with short-term maturities and variable rates refinanced at current market rates is a reasonable estimate of their fair value.

(2)   Carrying amount includes current portions included in securities due within one year and amounts which represent the unamortized debt issuance costs and discount or premium.

 

 
v3.21.2
Employee Benefit Plans (Tables)
 6 Months Ended
Jun. 30, 2021
Compensation And Retirement Disclosure [Abstract]  
Components of Net Periodic Benefit Cost

Components of net periodic benefit cost recorded by DESC were as follows:

(millions)

 

Pension Benefits

 

 

Other Postretirement Benefits

 

Three Months Ended June 30,

 

2021

 

 

2020

 

 

2021

 

 

2020

 

Service cost

 

$

1

 

 

$

4

 

 

$

—

 

 

$

1

 

Interest cost

 

 

5

 

 

 

6

 

 

 

2

 

 

 

2

 

Expected return on assets

 

 

(12

)

 

 

(11

)

 

 

—

 

 

 

—

 

Amortization of actuarial losses

 

 

1

 

 

 

1

 

 

 

—

 

 

 

—

 

Net periodic benefit cost (credit)

 

$

(5

)

 

$

—

 

 

$

2

 

 

$

3

 

Six Months Ended June 30,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Service cost

 

$

4

 

 

$

7

 

 

$

1

 

 

$

2

 

Interest cost

 

 

10

 

 

 

12

 

 

 

3

 

 

 

4

 

Expected return on assets

 

 

(24

)

 

 

(22

)

 

 

—

 

 

 

—

 

Amortization of actuarial losses

 

 

3

 

 

 

3

 

 

 

—

 

 

 

—

 

Net periodic benefit cost (credit)

 

$

(7

)

 

$

—

 

 

$

4

 

 

$

6

 

 

 
v3.21.2
Operating Segments (Tables)
 6 Months Ended
Jun. 30, 2021
Segment Reporting [Abstract]  
Schedule of Segment Reporting Information, by Segment

 

(millions)

 

External

Revenue

 

 

Comprehensive

Income (Loss)

Available

(Attributable) to

Common

Shareholder

 

Three Months Ended June 30, 2021

 

 

 

 

 

 

 

 

Dominion Energy South Carolina

 

$

692

 

 

$

79

 

Corporate and Other

 

 

—

 

 

 

(210

)

Consolidated Total

 

$

692

 

 

$

(131

)

 

 

 

 

 

 

 

 

 

Three Months Ended June 30, 2020

 

 

 

 

 

 

 

 

Dominion Energy South Carolina

 

$

624

 

 

$

77

 

Corporate and Other

 

 

—

 

 

 

(8

)

Consolidated Total

 

$

624

 

 

$

69

 

 

 

 

 

 

 

 

 

 

Six Months Ended June 30, 2021

 

 

 

 

 

 

 

 

Dominion Energy South Carolina

 

$

1,436

 

 

$

176

 

Corporate and Other

 

 

—

 

 

 

(256

)

Consolidated Total

 

$

1,436

 

 

$

(80

)

 

 

 

 

 

 

 

 

 

Six Months Ended June 30, 2020

 

 

 

 

 

 

 

 

Dominion Energy South Carolina

 

$

1,296

 

 

$

166

 

Corporate and Other

 

 

—

 

 

 

(9

)

Consolidated Total

 

$

1,296

 

 

$

157

 

 
v3.21.2
Affiliated and Related Party Transactions (Tables)
 6 Months Ended
Jun. 30, 2021
Related Party Transactions [Abstract]  
Schedule of Affiliated Transactions Amounts expensed are primarily recorded in other operations and maintenance - affiliated suppliers and other income (expense), net in the Consolidated Statements of Comprehensive Income (Loss).

 

 

 

Three Months Ended

June 30,

 

 

Six Months Ended

June 30,

 

(millions)

 

2021

 

 

2020

 

 

2021

 

 

2020

 

Direct and allocated costs from DES and DESS(1)

 

$

57

 

 

$

63

 

 

$

115

 

 

$

130

 

Operating Revenues - Electric from sales to affiliate

 

 

1

 

 

 

2

 

 

 

2

 

 

 

2

 

Operating Expenses - Other taxes from affiliate

 

 

2

 

 

 

1

 

 

 

4

 

 

 

4

 

Purchases of electricity from solar affiliates

 

 

5

 

 

 

4

 

 

 

7

 

 

 

6

 

Demand and transportation charges from DECG - Fuel used in

   electric generation

 

 

—

 

 

 

5

 

 

 

—

 

 

 

9

 

Demand and transportation charges from DECG - Gas purchased

   for resale

 

 

—

 

 

 

11

 

 

 

—

 

 

 

22

 

 

(1)

Includes capitalized expenditures of $10 million and $13 million for the three months ended June 30, 2021 and 2020, respectively, and $15 million and $25 million for the six months ended June 30, 2021 and 2020, respectively.
Schedule of Affiliated Transactions

 

(millions)

 

June 30, 2021

 

 

December 31, 2020

 

Payable to DES and DESS

 

$

1

 

 

$

59

 

Receivable from DES

 

 

2

 

 

 

—

 

Payable to Public Service Company of North Carolina, Incorporated

 

 

13

 

 

 

5

 

Payable to solar affiliates

 

 

2

 

 

 

1

 

Derivative assets with affiliates(1)

 

 

3

 

 

 

—

 

Derivative liabilities with affiliates(1)

 

 

7

 

 

 

—

 

 

(1)

Effective in the second quarter of 2021, contracts for the future purchase of certain quantities of electricity from solar affiliates no longer met the criteria for the normal purchase normal sale exception and are accounted for as derivative contracts.

 
v3.21.2
Other Income (Expense), Net (Tables)
 6 Months Ended
Jun. 30, 2021
Income Statement [Abstract]  
Components of Other Income (Expense), Net

Components of other income (expense), net are as follows:

 

 

 

Three Months Ended

June 30,

 

 

Six Months Ended

June 30,

 

(millions)

 

2021

 

 

2020

 

 

2021

 

 

2020

 

Revenues from contracts with customers

 

$

—

 

 

$

—

 

 

$

—

 

 

$

1

 

Other income

 

 

4

 

 

 

4

 

 

 

7

 

 

 

7

 

Other expense

 

 

(18

)

 

 

(3

)

 

 

(16

)

 

 

(5

)

Allowance for equity funds used during construction

 

 

2

 

 

 

1

 

 

 

3

 

 

 

2

 

Other income (expense), net

 

$

(12

)

 

$

2

 

 

$

(6

)

 

$

5

 
v3.21.2
Rate and Other Regulatory Matters (Narrative) (Detail) - USD ($)
$ in Millions
 1 Months Ended 3 Months Ended 6 Months Ended
Sep. 01, 2021
Jul. 31, 2021
Jun. 30, 2021
May 31, 2021
Apr. 30, 2021
Aug. 31, 2020
Jun. 30, 2021
Jun. 30, 2021
Jun. 30, 2020
Rate And Other Regulatory Matters [Line Items]                  
Other asset impairment charges             $ 249 $ 249  
Other asset impairment charges after tax             187 187  
Purchase of first mortgage bond             237 237  
Recovery under settlement agreement             18 18  
Recovery under settlement agreement after tax             14 $ 14  
South Carolina Commission order, revenue requirement under RSA     $ 426            
South Carolina Commission order, increase in natural gas rates under RSA     $ 9            
Regulatory asset recovery assessment end period               2047  
Impairment of assets and other charges               $ 319 $ 2
Reserve For Refunds To Electric Utility Customers [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Electric service customers recovery period               11 years  
Monetization Of Guaranty Settlement [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Electric service customers recovery period               20 years  
End period for recovery               2039  
Income Taxes Refundable Through Future Rates [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Remaining lives of related property period               85 years  
Deferred Losses or Gains On Interest Rate Derivatives [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Changes in fair value and payments of interest rate derivatives designated as cash flow hedge, amortized to interest expense, year               2043  
Changes in fair value and payments of interest rate derivatives not designed, amortized to interest, year               2065  
Dominion Energy South Carolina, Inc.                  
Rate And Other Regulatory Matters [Line Items]                  
Impairment of assets and other charges             237    
Impairment of assets and other charges, after-tax             $ 178    
Storm restoration recovery period               10 years  
Deferred depreciation and property taxes recovery period               40 years  
NND Project Costs [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Electric service customers recovery period               20 years  
End period for recovery               2039  
Deferred Employee Benefit Plan Costs [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Regulatory asset recovery assessment end period               2044  
Average service period expected to recover other deferred benefit costs               11 years  
Other Unrecovered Plant [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Amortization of carrying value of coal-fired generating unit               2025  
New expected amortization of carrying value of coal-fired generating unit               2028  
Demand Side Management Programs [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Recovery period of regulatory asset               3 years  
Asset Retirement Obligation Costs [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Recovery period of regulatory asset               105 years  
Environmental Remediation Costs [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Recovery period of regulatory asset               15 years  
Maximum [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Annual increase (decrease) in pension cost rider         $ (1)        
Fuel Component [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Annual increase (decrease) in total fuel cost component of retail electric rates         36        
DSM Programs [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
South Carolina Commission Order, Annual DSM Program Rate Rider Recovery Amount         $ 48        
DSM Programs [Member] | Forecast                  
Rate And Other Regulatory Matters [Line Items]                  
South Carolina Commission Order, Annual DSM Program Rate Rider Recovery Amount $ 43                
South Carolina Electric Base Rate Case                  
Rate And Other Regulatory Matters [Line Items]                  
Amount of Increase in proposed non fuel base rate           $ 178      
Increase in proposed non fuel base rate           7.75%      
Percentage of ROE based on fully adjusted test period           5.90%      
Percentage of current authorized earned ROE           10.25%      
South Carolina Office of Regulatory Staff and Other Parties [Member]                  
Rate And Other Regulatory Matters [Line Items]                  
Amount of Increase in proposed non fuel base rate   $ 62              
Percentage of current authorized earned ROE   9.50%              
Retail electric customer balance   $ 15              
Welfare charges for customers   15              
Due days for forgive retail electric customer balance       60 days          
Non fuel base rate increase after amortization   $ 36              
v3.21.2
Rate and Other Regulatory Matters (Schedule of Regulatory Assets) (Detail) - USD ($)
$ in Millions
Jun. 30, 2021
Dec. 31, 2020
Regulatory Assets    
Regulatory assets, current $ 212 $ 229
Regulatory assets, noncurrent 3,460 3,726
Total regulatory assets 3,672 3,955
NND Project Costs [Member]    
Regulatory Assets    
Regulatory assets, current [1] 138 138
Regulatory assets, noncurrent [1] 2,295 2,364
Deferred Employee Benefit Plan Costs [Member]    
Regulatory Assets    
Regulatory assets, current [2] 8 9
Regulatory assets, noncurrent [2] 156 159
Other Unrecovered Plant [Member]    
Regulatory Assets    
Regulatory assets, current [3] 15 14
Regulatory assets, noncurrent [3] 59 61
Demand Side Management Programs [Member]    
Regulatory Assets    
Regulatory assets, current [4] 23 29
Regulatory assets, noncurrent [4] 46 46
Other Regulatory Assets [Member]    
Regulatory Assets    
Regulatory assets, current 26 36
Regulatory assets, noncurrent [5] 141 108
Asset Retirement Obligation Costs [Member]    
Regulatory Assets    
Regulatory assets, current [6] 2 2
Regulatory assets, noncurrent [6] 311 309
Cost of Fuel and Purchased Gas Under-Collections [Member]    
Regulatory Assets    
Regulatory assets, current [7] 0 1
Deferred Losses On Interest Rate Derivatives [Member]    
Regulatory Assets    
Regulatory assets, noncurrent [8] 300 308
Cost of Reacquired Debt [Member]    
Regulatory Assets    
Regulatory assets, noncurrent [9] 11 243
Environmental Remediation Costs [Member]    
Regulatory Assets    
Regulatory assets, noncurrent [10] 20 20
Deferred Storm Damage Costs [Member]    
Regulatory Assets    
Regulatory assets, noncurrent [11] 45 45
Deferred Transmission Operating Costs [Member]    
Regulatory Assets    
Regulatory assets, noncurrent [12] $ 76 $ 63
[1] Reflects expenditures associated with the NND Project, which pursuant to the SCANA Merger Approval Order, will be recovered from electric service customers over a 20-year period ending in 2039. See Note 10 for more information.
[2] Employee benefit plan costs have historically been recovered as they have been recorded under GAAP. Deferred employee benefit plan costs represent amounts of pension and other postretirement benefit costs which were accrued as liabilities and treated as regulatory assets pursuant to FERC guidance, and costs deferred pursuant to specific South Carolina Commission regulatory orders. DESC expects to recover deferred pension costs through utility rates over periods through 2044. DESC expects to recover other deferred benefit costs through utility rates, primarily over average service periods of participating employees up to 11 years.
[3] Represents the carrying value of coal-fired generating units, including related materials and supplies inventory, retired from service prior to being fully depreciated. DESC is amortizing these amounts through cost of service rates following deprecation amounts that were designed to recover the retired units’ cost over their previous estimated remaining useful lives, which has been estimated to be through 2025. Based on
[4] Represents deferred costs associated with electric demand reduction programs, and such deferred costs are currently being recovered over three years through an approved rate rider.
[5] Various other regulatory assets are expected to be recovered through rates over varying periods through 2047.
[6] Represents deferred depreciation and accretion expense related to legal obligations associated with the future retirement of generation, transmission and distribution properties. The AROs primarily relate to DESC’s electric generating facilities, including Summer, and are expected to be recovered over the related property lives and periods of decommissioning which may range up to approximately 105 years.
[7] Represents amounts under- or over-collected from customers pursuant to the cost of fuel and purchased gas components approved by the South Carolina Commission.
[8] Represents (i) the changes in fair value and payments made or received upon settlement of certain interest rate derivatives designated as cash flow hedges and (ii) the changes in fair value and payments made or received upon settlement of certain other interest rate derivatives not so designated. The amounts recorded with respect to (i) are expected to be amortized to interest expense over the lives of the underlying debt through 2043.The amounts recorded with respect to (ii) are expected to be similarly amortized to interest expense through 2065.
[9] During the second quarter of 2021, DESC recorded a charge of $237 million ($178 million after-tax) in impairment of assets and other charges to write-off the balance of a regulatory asset that is no longer probable of recovery under the settlement agreement approved in DESC’s retail electric base rate case. See South Carolina Electric Base Rate Case discussed above for more information.
[10] Reflects amounts associated with the assessment and clean-up of sites currently or formerly owned by DESC. Such remediation costs are expected to be recovered over periods of up to 15 years. See Note 10 for more information.
[11] Represents storm restoration costs for which DESC expects to recover through customer rates over approximately 10 years pursuant to the settlement agreement approved in DESC’s retail electric base rate case.
[12] Includes deferred depreciation and property taxes associated with certain transmission assets for which DESC expects to recover from customers over approximately 40 years pursuant to the settlement agreement approved in DESC’s retail electric base rate case.
v3.21.2
Rate and Other Regulatory Matters (Schedule of Regulatory Liabilities) (Detail) - USD ($)
$ in Millions
Jun. 30, 2021
Dec. 31, 2020
Regulatory Liabilities    
Regulatory liability, current $ 285 $ 283
Regulatory liability, noncurrent 2,901 3,005
Total regulatory liabilities 3,186 3,288
Monetization Of Guaranty Settlement [Member]    
Regulatory Liabilities    
Regulatory liability, current [1] 67 67
Regulatory liability, noncurrent [1] 869 903
Income Taxes Refundable Through Future Rates [Member]    
Regulatory Liabilities    
Regulatory liability, current [2] 36 21
Regulatory liability, noncurrent [2] 893 919
Reserve For Refunds To Electric Utility Customers [Member]    
Regulatory Liabilities    
Regulatory liability, current [3] 123 128
Regulatory liability, noncurrent [3] 475 540
Other Regulatory Liability [Member]    
Regulatory Liabilities    
Regulatory liability, current 21 9
Regulatory liability, noncurrent 24 10
Asset Removal Cost [Member]    
Regulatory Liabilities    
Regulatory liability, noncurrent [4] 572 564
Cost of Fuel and Purchased Gas Under-Collections [Member]    
Regulatory Liabilities    
Regulatory liability, current [5] 38 58
Deferred Gains On Interest Rate Derivatives [Member]    
Regulatory Liabilities    
Regulatory liability, noncurrent [6] $ 68 $ 69
[1] Represents proceeds related to the monetization of the Toshiba Settlement. In accordance with the SCANA Merger Approval Order, this balance, net of amounts that may be required to satisfy liens, will be refunded to electric customers over a 20-year period ending in 2039. See Note 12 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020.
[2] Includes (i) excess deferred income taxes arising from the remeasurement of deferred income taxes in connection with the enactment of the 2017 Tax Reform Act (certain of which are protected under normalization rules and will be amortized over the remaining lives of related property, and certain of which will be amortized to the benefit of customers over prescribed periods as instructed by regulators) and (ii) deferred income taxes arising from investment tax credits, offset by (iii) deferred income taxes that arise from utility operations that have not been included in customer rates (a portion of which relate to depreciation and are expected to be recovered over the remaining lives of the related property which may range up to 85 years). See Note 6 for more information.
[3] Reflects amounts previously collected from retail electric customers of DESC for the NND Project to be credited to customers over an estimated 11-year period effective February 2019 in connection with the SCANA Merger Approval Order. See Note 12 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2020.
[4] Represents estimated net collections through depreciation rates of amounts to be expended for the removal of assets in the future.
[5] Represents amounts under- or over-collected from customers pursuant to the cost of fuel and purchased gas components approved by the South Carolina Commission.
[6] Represents (i) the changes in fair value and payments made or received upon settlement of certain interest rate derivatives designated as cash flow hedges and (ii) the changes in fair value and payments made or received upon settlement of certain other interest rate derivatives not so designated. The amounts recorded with respect to (i) are expected to be amortized to interest expense over the lives of the underlying debt through 2043.The amounts recorded with respect to (ii) are expected to be similarly amortized to interest expense through 2065.
v3.21.2
Revenue Recognition (Disaggregation of Revenue) (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Operating revenue from contracts with customers $ 0 $ 0 $ 0 $ 1
Total Operating Revenues [1] 692 624 1,436 1,296
Electric Operations        
Operating revenue from contracts with customers 603 548 1,174 1,085
Other revenues 0 7 8 9
Total Operating Revenues 603 555 1,182 1,094
Gas Distribution        
Operating revenue from contracts with customers 89 69 253 202
Other revenues 0 0 1 0
Total Operating Revenues 89 69 254 202
Residential | Electric Operations        
Operating revenue from contracts with customers 271 261 546 513
Residential | Gas Distribution        
Operating revenue from contracts with customers 38 33 136 112
Commercial | Electric Operations        
Operating revenue from contracts with customers 199 177 374 352
Commercial | Gas Distribution        
Operating revenue from contracts with customers 26 20 65 53
Industrial | Electric Operations        
Operating revenue from contracts with customers 95 83 183 163
Industrial | Gas Distribution        
Operating revenue from contracts with customers 18 12 40 29
Other | Electric Operations        
Operating revenue from contracts with customers 38 27 71 57
Other | Gas Distribution        
Operating revenue from contracts with customers $ 7 $ 4 $ 12 $ 8
[1] See Note 12 for amounts attributable to affiliates.
v3.21.2
Revenue Recognition (Narrative) (Detail) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Dec. 31, 2020
Revenue From Contract With Customer [Abstract]      
Contract liability balances $ 7   $ 5
Revenue recognized from contract liability balances $ 3 $ 5  
v3.21.2
Equity (Narrative) (Detail) - USD ($)
$ / shares in Units, $ in Millions
 1 Months Ended 9 Months Ended
Jul. 31, 2021
Sep. 30, 2020
Jun. 30, 2021
Dec. 31, 2020
Class Of Stock [Line Items]        
Common stock, par value     $ 0 $ 0
Common stock, shares authorized     50,000,000 50,000,000
Common stock, shares issued     40,300,000 40,300,000
Common stock, shares outstanding     40,300,000 40,300,000
Preferred stock, par value     $ 0 $ 0
Preferred stock, shares authorized     20,000,000 20,000,000
Preferred stock, shares issued     1,000 1,000
Preferred stock, shares outstanding     1,000 1,000
Dominion Energy [Member] | Common Stock        
Class Of Stock [Line Items]        
Common stock issued to satisfy the settlement   $ 322    
Dominion Energy [Member] | Subsequent Event [Member] | Common Stock | FILOT        
Class Of Stock [Line Items]        
Common stock issued to satisfy the settlement $ 104      
Dominion Energy [Member] | Subsequent Event [Member] | Common Stock | SCDOR        
Class Of Stock [Line Items]        
Common stock issued to satisfy the settlement $ 45      
v3.21.2
Long-Term and Short-Term Debt (Narrative) (Detail) - USD ($)
 1 Months Ended 3 Months Ended 6 Months Ended
Jan. 31, 2020
Jul. 31, 2021
Mar. 31, 2021
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Dec. 31, 2020
Debt Instrument [Line Items]                
Commercial paper borrowing limit     $ 2,200,000,000          
Commercial paper maturity period     2023-03          
Short Term Borrowing Maturity Period 2 years              
Interest charges [1]       $ 54,000,000 $ 58,000,000 $ 109,000,000 $ 116,000,000  
Interest income from money pool transactions         1,000,000   2,000,000  
Interest expense from money pool transactions         1,000,000   2,000,000  
Maximum [Member]                
Debt Instrument [Line Items]                
Interest income from money pool transactions           1,000,000    
Interest expense from money pool transactions           1,000,000    
FERC | Maximum [Member]                
Debt Instrument [Line Items]                
Short term commercial paper maturity period     1 year          
Genco                
Debt Instrument [Line Items]                
Commercial paper borrowing limit     $ 200,000,000          
Investments due from affiliates               $ 15,000,000
Genco | Maximum [Member]                
Debt Instrument [Line Items]                
Short term commercial paper maturity period     1 year          
Fuel Company                
Debt Instrument [Line Items]                
Money pool borrowings due to affiliates               206,000,000
Dominion Energy [Member]                
Debt Instrument [Line Items]                
Short-term borrowings outstanding, maximum           900,000,000    
Short-term borrowings outstanding       542,000,000   542,000,000   $ 149,000,000
Interest charges       2,000,000 $ 3,000,000 4,000,000 $ 5,000,000  
Joint Revolving Credit Facility                
Debt Instrument [Line Items]                
Facility limit [2]       1,000,000,000   1,000,000,000    
Joint Revolving Credit Facility | Dominion Energy [Member]                
Debt Instrument [Line Items]                
Facility limit       6,000,000,000.0   6,000,000,000.0    
Letter of Credit                
Debt Instrument [Line Items]                
Facility limit       1,000,000,000.0   1,000,000,000.0    
Debt instrument, face amount       $ 68,000,000   $ 68,000,000    
3.22% First Mortgage Bond [Member] | Subsequent Event [Member]                
Debt Instrument [Line Items]                
Redemption of remaining principal outstanding plus accrued interest   $ 30,000,000            
Debt instrument, interest rate   3.22%            
Debt instrument, maturity date   2021-10            
[1]

See Note 5 for amounts attributable to affiliates.
[2]

A maximum of $1.0 billion of the facility is available to DESC, assuming adequate capacity is available after giving effect to uses by co-borrowers Dominion Energy, Virginia Power and Questar Gas. The sub-limit for DESC is set within the facility limit but can be changed at the option of the co-borrowers multiple times per year. At June 30, 2021, the sub-limit for DESC was $500 million. If DESC has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from DESC's parent or from Dominion Energy. This credit facility matures in June 2026, with the potential to be extended by the borrowers to June 2028. The credit facility can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $1.0 billion (or the sub-limit, whichever is less) of letters of credit.

v3.21.2
Long-Term and Short-Term Debt (Schedule of Line of Credit Facilities) (Detail) - Joint Revolving Credit Facility
Jun. 30, 2021
USD ($)
 [1]
Debt Instrument [Line Items]  
Facility limit $ 1,000,000,000
Outstanding Commercial Paper 60,000,000
Outstanding Letters of Credit $ 0
[1]

A maximum of $1.0 billion of the facility is available to DESC, assuming adequate capacity is available after giving effect to uses by co-borrowers Dominion Energy, Virginia Power and Questar Gas. The sub-limit for DESC is set within the facility limit but can be changed at the option of the co-borrowers multiple times per year. At June 30, 2021, the sub-limit for DESC was $500 million. If DESC has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from DESC's parent or from Dominion Energy. This credit facility matures in June 2026, with the potential to be extended by the borrowers to June 2028. The credit facility can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $1.0 billion (or the sub-limit, whichever is less) of letters of credit.

v3.21.2
Long-Term and Short-Term Debt (Schedule of Line of Credit Facilities) (Parenthetical) (Detail)
 6 Months Ended
Jun. 30, 2021
USD ($)
Minimum [Member]  
Debt Instrument [Line Items]  
Line of credit facility maturity date 2026-06
Maximum [Member]  
Debt Instrument [Line Items]  
Line of credit facility maturity date 2028-06
Joint Revolving Credit Facility  
Debt Instrument [Line Items]  
Facility limit $ 1,000,000,000 [1]
Line of Credit Facility  
Debt Instrument [Line Items]  
Facility limit 500,000,000
Letter of Credit  
Debt Instrument [Line Items]  
Facility limit $ 1,000,000,000.0
[1]

A maximum of $1.0 billion of the facility is available to DESC, assuming adequate capacity is available after giving effect to uses by co-borrowers Dominion Energy, Virginia Power and Questar Gas. The sub-limit for DESC is set within the facility limit but can be changed at the option of the co-borrowers multiple times per year. At June 30, 2021, the sub-limit for DESC was $500 million. If DESC has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from DESC's parent or from Dominion Energy. This credit facility matures in June 2026, with the potential to be extended by the borrowers to June 2028. The credit facility can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $1.0 billion (or the sub-limit, whichever is less) of letters of credit.

v3.21.2
Income Taxes (Narrative) (Detail)
 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Income Tax Disclosure [Abstract]    
Effective tax rate, percent 33.60% 21.50%
v3.21.2
Derivative Financial Instruments (Offsetting Liabilities) (Parenthetical) (Detail) - USD ($)
$ in Millions
Jun. 30, 2021
Dec. 31, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]    
Derivative liabilities not subject to master netting or similar arrangements $ 28 $ 0
v3.21.2
Derivative Financial Instruments (Narrative) (Detail) - USD ($)
$ in Millions
Jun. 30, 2021
Dec. 31, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]    
Additional collateral to its counterparties $ 11 $ 10
Collateral already posted 11 1
Fair value of derivative instruments with credit-related contingent provisions that are in liability position and not fully collateralized with cash $ 22 $ 11
v3.21.2
Derivative Financial Instruments (Offsetting Liabilities) (Detail) - USD ($)
$ in Millions
Jun. 30, 2021
Dec. 31, 2020
Derivative [Line Items]    
Gross assets presented in the consolidated balance sheet $ 15  
Liability    
Derivative [Line Items]    
Gross assets presented in the consolidated balance sheet [1] 22 $ 27
Gross amounts not offset in the consolidated balance sheet, financial instruments 0 0
Gross amounts not offset in the consolidated balance sheet, cash collateral received 11 17
Gross amounts not offset in the consolidated balance sheet, net amounts 11 10
Liability | Interest Rate Contract [Member] | Over The Counter [Member]    
Derivative [Line Items]    
Gross assets presented in the consolidated balance sheet [1] 22 27
Gross amounts not offset in the consolidated balance sheet, financial instruments 0 0
Gross amounts not offset in the consolidated balance sheet, cash collateral received 11 17
Gross amounts not offset in the consolidated balance sheet, net amounts $ 11 $ 10
[1] Excludes $28 million and $— million of derivative liabilities at June 30, 2021 and December 31, 2020, respectively, which are not subject to master netting or similar arrangements.
v3.21.2
Derivative Financial Instruments (Schedule of Volume of Derivative Activity) (Detail)
$ in Millions
Jun. 30, 2021
USD ($)
Interest Rate Swap Current [Member]  
Derivative [Line Items]  
Interest rate $ 0 [1]
Interest Rate Swap Current [Member] | Electricity [Member]  
Derivative [Line Items]  
Fixed price 1,642,960
Interest Rate Swap Noncurrent [Member]  
Derivative [Line Items]  
Interest rate 71 [1]
Interest Rate Swap Noncurrent [Member] | Electricity [Member]  
Derivative [Line Items]  
Fixed price $ 23,508,146
[1] Maturity is determined based on final settlement period.
v3.21.2
Derivative Financial Instruments (Fair Value of Derivatives) (Detail) - USD ($)
$ in Millions
Jun. 30, 2021
Dec. 31, 2020
Derivative [Line Items]    
Derivative Assets $ 15  
Derivative Liability 50 $ 27
Other Current Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability [1] 2 2
Other Current Assets [Member]    
Derivative [Line Items]    
Derivative Assets [2] 5  
Other Noncurrent Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability [3] 48 25
Other Noncurrent Assets [Member]    
Derivative [Line Items]    
Derivative Assets [4] 10  
Interest Rate Contract [Member] | Other Current Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability 2 2
Interest Rate Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability 20 25
Commodity Contract [Member] | Other Current Assets [Member]    
Derivative [Line Items]    
Derivative Assets 5  
Commodity Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability 28  
Commodity Contract [Member] | Other Noncurrent Assets [Member]    
Derivative [Line Items]    
Derivative Assets 10  
Designated as Hedging Instrument [Member]    
Derivative [Line Items]    
Derivative Assets 0  
Derivative Liability 13 16
Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability [1] 1 1
Designated as Hedging Instrument [Member] | Other Current Assets [Member]    
Derivative [Line Items]    
Derivative Assets [2] 0  
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability [3] 12 15
Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member]    
Derivative [Line Items]    
Derivative Assets [4] 0  
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other Current Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability 1 1
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability 12 15
Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Current Assets [Member]    
Derivative [Line Items]    
Derivative Assets 0  
Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability 0  
Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Noncurrent Assets [Member]    
Derivative [Line Items]    
Derivative Assets 0  
Not Designated as Hedging Instrument [Member]    
Derivative [Line Items]    
Derivative Assets 15  
Derivative Liability 37 11
Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability [1] 1 1
Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]    
Derivative [Line Items]    
Derivative Assets [2] 5  
Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability [3] 36 10
Not Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member]    
Derivative [Line Items]    
Derivative Assets [4] 10  
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other Current Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability 1 1
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability 8 $ 10
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Current Assets [Member]    
Derivative [Line Items]    
Derivative Assets 5  
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivative [Line Items]    
Derivative Liability 28  
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Noncurrent Assets [Member]    
Derivative [Line Items]    
Derivative Assets $ 10  
[1] Current derivative liabilities are presented in other current liabilities in the Consolidated Balance Sheets.
[2] Current derivative assets are presented in other current assets in the Consolidated Balance Sheets.
[3] Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in the Consolidated Balance Sheets.
[4] Noncurrent derivative assets are presented in other deferred debits and other assets in the Consolidated Balance Sheets.
v3.21.2
Derivative Financial Instruments (Derivatives in Cash Flow Hedging Relationships) (Detail) - Cash Flow Hedging [Member] - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Derivative [Line Items]        
Increase (Decrease) in Derivatives Subject to Regulatory Treatment [1] $ (1) $ 2 $ 6 $ (4)
Interest Rate Contract [Member]        
Derivative [Line Items]        
Increase (Decrease) in Derivatives Subject to Regulatory Treatment [1] $ (1) $ 2 $ 6 $ (4)
[1] Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/ liabilities have no associated effect in the Consolidated Statements of Comprehensive Income (Loss).
v3.21.2
Derivative Financial Instruments (Derivatives Not Designated as Hedging Instruments) (Detail) - Not Designated as Hedging Instrument [Member] - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Derivative [Line Items]    
Amount of Gain (Loss) Recognized in Income on Derivatives [1] $ (1) $ 0
Interest Rate Contract [Member] | Interest Charges [Member    
Derivative [Line Items]    
Amount of Gain (Loss) Recognized in Income on Derivatives [1] $ (1) $ 0
[1] Includes derivative activity amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in the Consolidated Statements of Comprehensive Income (Loss).
v3.21.2
Fair Value Measurements, Including Derivatives (Schedule of Quantitative Information About Level 3 Fair Value Measurements) (Details)
$ in Millions
Jun. 30, 2021
USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]  
Gross assets presented in the consolidated balance sheet $ 15
Total Liabilities, fair value 28
Electricity [Member]  
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]  
Gross assets presented in the consolidated balance sheet 15
Total Liabilities, fair value 28
Minimum [Member] | Electricity [Member]  
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]  
Gross assets presented in the consolidated balance sheet 23
Total Liabilities, fair value 23
Maximum [Member] | Electricity [Member]  
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]  
Gross assets presented in the consolidated balance sheet 54
Total Liabilities, fair value 55
Weighted Average [Member] | Electricity [Member]  
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]  
Gross assets presented in the consolidated balance sheet 35
Total Liabilities, fair value $ 35
v3.21.2
Fair Value Measurements, Including Derivatives (Schedule of Liabilities Measured at Fair Value on Recurring Basis) (Details) - Fair value, recurring - USD ($)
$ in Millions
Jun. 30, 2021
Dec. 31, 2020
Assets    
Total assets $ 15  
Liabilities    
Total liabilities 50 $ 27
Commodity Contract [Member]    
Assets    
Total assets 15  
Liabilities    
Total liabilities 28  
Interest Rate Contract [Member]    
Liabilities    
Total liabilities 22 27
Level 1    
Assets    
Total assets 0  
Liabilities    
Total liabilities 0 0
Level 1 | Commodity Contract [Member]    
Assets    
Total assets 0  
Liabilities    
Total liabilities 0  
Level 1 | Interest Rate Contract [Member]    
Liabilities    
Total liabilities 0 0
Level 2    
Assets    
Total assets 0  
Liabilities    
Total liabilities 22 27
Level 2 | Commodity Contract [Member]    
Assets    
Total assets 0  
Liabilities    
Total liabilities 0  
Level 2 | Interest Rate Contract [Member]    
Liabilities    
Total liabilities 22 27
Level 3    
Assets    
Total assets 15  
Liabilities    
Total liabilities 28 0
Level 3 | Commodity Contract [Member]    
Assets    
Total assets 15  
Liabilities    
Total liabilities 28  
Level 3 | Interest Rate Contract [Member]    
Liabilities    
Total liabilities $ 0 $ 0
v3.21.2
Fair Value Measurements, Including Derivatives (Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2021
Regulatory Assets    
Beginning balance $ 0 $ 0
Total realized and unrealized losses:    
Ending balance (13) (13)
Other Regulatory Assets Liabilities    
Total realized and unrealized losses:    
Included in regulatory assets/liabilities $ (13) $ (13)
v3.21.2
Fair Value Measurements, Including Derivatives (Schedule of Carrying Values and Estimated Fair Values of Debt Instruments) (Detail) - USD ($)
$ in Millions
Jun. 30, 2021
Dec. 31, 2020
Carrying Amount    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Long-term debt [1] $ 3,360 $ 3,360
Affiliated long-term debt 230 230
Estimated Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Long-term debt [1],[2] 4,515 4,748
Affiliated long-term debt [2] $ 230 $ 230
[1] Carrying amount includes current portions included in securities due within one year and amounts which represent the unamortized debt issuance costs and discount or premium.
[2] Fair value is estimated using market prices, where available, and interest rates currently available for issuance of debt with similar terms and remaining maturities. All fair value measurements are classified as Level 2. The carrying amount of debt issuances with short-term maturities and variable rates refinanced at current market rates is a reasonable estimate of their fair value.
v3.21.2
Employee Benefit Plans (Components of Net Periodic Benefit Cost (Credit) (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Pension Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost $ 1 $ 4 $ 4 $ 7
Interest cost 5 6 10 12
Expected return on assets (12) (11) (24) (22)
Amortization of actuarial losses 1 1 3 3
Net periodic benefit cost (credit) (5) 0 (7) 0
Other Postretirement Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 0 1 1 2
Interest cost 2 2 3 4
Expected return on assets 0 0 0 0
Amortization of actuarial losses 0 0 0 0
Net periodic benefit cost (credit) $ 2 $ 3 $ 4 $ 6
v3.21.2
Employee Benefit Plans (Narrative) (Detail)
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2021
Compensation And Retirement Disclosure [Abstract]    
Defined benefit plan, expected future employer contributions, next fiscal year, description no no
v3.21.2
Commitments and Contingencies (Narrative) (Detail)
shares in Millions
 1 Months Ended 3 Months Ended 6 Months Ended 9 Months Ended
Oct. 31, 2014
MGD
Facility
Aug. 31, 2021
shares
Jul. 31, 2021
USD ($)
shares
Jun. 30, 2021
USD ($)
shares
Mar. 31, 2021
USD ($)
Dec. 31, 2020
USD ($)
Sep. 30, 2020
USD ($)
Aug. 31, 2020
USD ($)
Sep. 30, 2019
USD ($)
Jul. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Jun. 30, 2018
USD ($)
Aug. 31, 2017
USD ($)
Aug. 31, 2016
T
Jun. 30, 2021
USD ($)
Jun. 30, 2021
USD ($)
Product
Jun. 30, 2020
USD ($)
Sep. 30, 2020
USD ($)
Mar. 31, 2020
USD ($)
Loss Contingencies [Line Items]                                      
Electric generating stations with water withdrawals under CWA | MGD 125                                    
Electric generating stations with water withdrawals with heightened entrainment analysis under CWA | MGD 2                                    
Number of DESC facilities subject to final regulations | Facility 5                                    
Number of DESC hydroelectric facilities subject to regulations | Facility 5                                    
Number of manufacturing gas plant decommissioned sites that contain residues of byproduct chemicals | Product                               4      
Estimated environmental remediation activities at manufacturing gas plant sites                               $ 9,000,000      
Estimated increase in remediation costs for Congaree River site                               11,000,000      
Environmental remediation costs recognized in regulatory assets       $ 22,000,000                     $ 22,000,000 22,000,000      
Reserves for litigation and regulatory proceedings       278,000,000   $ 208,000,000                 278,000,000 278,000,000      
Insurance receivables       23,000,000   8,000,000                 23,000,000 23,000,000      
Impairment of assets and other charges                               319,000,000 $ 2,000,000    
Settlement payable by all                                     $ 520,000,000
Settlement payable by company     $ 99,000,000                   $ 100,000,000           $ 320,000,000
Proportionate ownership share in project                       100.00% 100.00%            
Proposed assessment amount from SCDOR audit                       $ 410,000,000              
Litigation settlement expense awarded           165,000,000                          
Contesting amount for filed liens in Fairfield country                               285,000,000      
Reduction of liens filed                               $ 60,000,000      
Percentage share of reduction of liens filed                               55.00%      
Nuclear Insurance                                      
Loss Contingencies [Line Items]                                      
Maximum liability protection per nuclear incident amount       $ 13,500,000,000 $ 13,700,000,000                            
Common Stock | Dominion Energy                                      
Loss Contingencies [Line Items]                                      
Common stock issued to satisfy the settlement                                   $ 322,000,000  
Shares issued on settlement | shares   0.6 1.4 43.0                              
DESC Ratepayer Case                                      
Loss Contingencies [Line Items]                                      
Escrow amount                     $ 2,000,000,000.0                
Credit in future electric rate relief for ratepayer case                     2,000,000,000.0                
Cash payment related to Ratepayer Case                   $ 117,000,000 115,000,000                
Property with net value transferred               $ 22,000,000                      
Property with net value transferred, cash contribution             $ 38,500,000                        
Conveyance of property with net recorded value             $ 3,000,000                        
Minimum [Member] | DESC Ratepayer Case                                      
Loss Contingencies [Line Items]                                      
Estimated aggregate fair value of certain real estate                     60,000,000                
Maximum [Member] | Nuclear Insurance                                      
Loss Contingencies [Line Items]                                      
Maximum liability protection per nuclear incident amount       $ 13,700,000,000 $ 13,800,000,000                            
Maximum [Member] | DESC Ratepayer Case                                      
Loss Contingencies [Line Items]                                      
Estimated aggregate fair value of certain real estate                     $ 85,000,000                
Dominion Energy South Carolina, Inc.                                      
Loss Contingencies [Line Items]                                      
Reduction of liens filed                               $ 33,000,000      
Dominion Energy South Carolina, Inc. | Wrongful Death Suit of Estate of Jose Larios                                      
Loss Contingencies [Line Items]                                      
Litigation settlement expense awarded                 $ 19,000,000                    
SCANA                                      
Loss Contingencies [Line Items]                                      
Payment of civil monetary penalty           25,000,000                          
SCANA and DESC                                      
Loss Contingencies [Line Items]                                      
Settlement payable by company       $ 0                     0 0      
Payment of disgorgement and prejudgment interest           $ 112,500,000                          
Impairment Of Assets And Other Charges | Dominion Energy South Carolina, Inc.                                      
Loss Contingencies [Line Items]                                      
Impairment of assets and other charges                             10,000,000 70,000,000      
Impairment of assets and other charges, after-tax                             $ 8,000,000 $ 53,000,000      
Carbon Regulations [Member]                                      
Loss Contingencies [Line Items]                                      
Significant emission rate per year CO2 equivalent | T                           75,000          
v3.21.2
Operating Segments (Narrative) (Details) - Operating Segments - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Dominion Energy South Carolina, Inc.    
Segment Reporting Information [Line Items]    
After- tax net expenses $ 256 $ 7
SCANA    
Segment Reporting Information [Line Items]    
Litigation charges 70  
Litigation charges, after tax 53  
South Carolina Electric Base Rate Case    
Segment Reporting Information [Line Items]    
Settlement charges 266  
Settlement charges net of tax $ 199  
v3.21.2
Operating Segments - Schedule of Segment Information (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Segment Reporting Information [Line Items]        
External revenue $ 692 $ 624 $ 1,436 $ 1,296
Comprehensive income (loss) available (attributable) to common shareholder (131) 69 (80) 157
Dominion Energy South Carolina, Inc. | Operating Segments        
Segment Reporting Information [Line Items]        
External revenue 692 624 1,436 1,296
Comprehensive income (loss) available (attributable) to common shareholder 79 77 176 166
Corporate and Other | Operating Segments        
Segment Reporting Information [Line Items]        
External revenue 0 0 0 0
Comprehensive income (loss) available (attributable) to common shareholder $ (210) $ (8) $ (256) $ (9)
v3.21.2
Affiliated and Related Party Transactions (Narrative) (Detail)
Jun. 30, 2021
Canadys Refined Coal [Member]  
Related Party Transaction [Line Items]  
Ownership percentage 40.00%
v3.21.2
Affiliated and Related Party Transactions (Schedule of Affiliated Transactions - Income Statement) (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Related Party Transaction [Line Items]        
Operating Revenues - Electric from sales to affiliate $ 1 $ 2 $ 2 $ 2
Operating Expenses - Other taxes from affiliate 2 1 4 4
DES & DESS [Member]        
Related Party Transaction [Line Items]        
Purchases from affiliate [1] 57 63 115 130
Solar Affiliates [Member]        
Related Party Transaction [Line Items]        
Purchases from affiliate 5 4 7 6
DECG [Member]        
Related Party Transaction [Line Items]        
Purchases of fuel used in electric generation from affiliate 0 5 0 9
Gas purchased for resale $ 0 $ 11 $ 0 $ 22
[1] Includes capitalized expenditures of $10 million and $13 million for the three months ended June 30, 2021 and 2020, respectively, and $15 million and $25 million for the six months ended June 30, 2021 and 2020, respectively.
v3.21.2
Affiliated and Related Party Transactions (Schedule of Affiliated Transactions - Income Statement) (Parenthetical) (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
DES & DESS [Member]        
Related Party Transaction [Line Items]        
Capitalized expenditures $ 10 $ 13 $ 15 $ 25
v3.21.2
Affiliated and Related Party Transactions (Schedule of Affiliated Transactions - Balance Sheet) (Detail) - USD ($)
$ in Millions
Jun. 30, 2021
Dec. 31, 2020
Related Party Transaction [Line Items]    
Derivative assets with affiliates [1] $ 3 $ 0
Derivative liabilities with affiliates [1] 7 0
Solar Affiliates [Member]    
Related Party Transaction [Line Items]    
Payable to affiliates 2 1
DES & DESS [Member]    
Related Party Transaction [Line Items]    
Payable to affiliates 1 59
DES [Member]    
Related Party Transaction [Line Items]    
Receivable from affiliates 2 0
Public Service Company of North Carolina, Incorporated [Member]    
Related Party Transaction [Line Items]    
Payable to affiliates $ 13 $ 5
[1]

Effective in the second quarter of 2021, contracts for the future purchase of certain quantities of electricity from solar affiliates no longer met the criteria for the normal purchase normal sale exception and are accounted for as derivative contracts.
v3.21.2
Other Income (Expense), Net (Components of Other Income (Expense), Net) (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Income Statement [Abstract]        
Operating revenue from contracts with customers $ 0 $ 0 $ 0 $ 1
Other income 4 4 7 7
Other expense (18) (3) (16) (5)
Allowance for equity funds used during construction 2 1 3 2
Other income (expense), net $ (12) $ 2 $ (6) $ 5