Document and Entity Information
Document and Entity Information - shares | 3 Months Ended | |
Mar. 31, 2024 | Apr. 26, 2024 | |
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 | 2024 | |
Document Fiscal Period Focus | Q1 | |
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 | 220 OPERATION WAY | |
Entity Address, City or Town | CAYCE | |
Entity Address, State or Province | SC | |
Entity Address, Postal Zip Code | 29033 | |
City Area Code | 804 | |
Local Phone Number | 819-2284 | |
Entity Incorporation, State or Country Code | SC | |
Document Quarterly Report | true | |
Document Transition Report | false | |
Entity Interactive Data Current | Yes | |
Document Period End Date | Mar. 31, 2024 |
Consolidated Balance Sheets (Un
Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023 | |
ASSETS | |||
Utility plant in service | $ 15,570 | $ 15,500 | |
Accumulated depreciation and amortization | (5,591) | (5,557) | |
Construction work in progress | 702 | 606 | |
Nuclear fuel, net of accumulated amortization | 226 | 229 | |
Utility plant, net | 10,907 | 10,778 | |
Nonutility Property and Investments: | |||
Nonutility property, net of accumulated depreciation | 24 | 24 | |
Assets held in trust, nuclear decommissioning | 254 | 247 | |
Nonutility property and investments, net | 278 | 271 | |
Current Assets: | |||
Cash and cash equivalents | 4 | 1 | |
Customer, net of allowance for uncollectible accounts of $8 and $6 | 399 | 420 | |
Receivables, other | 63 | 97 | |
Inventories (at average cost): | |||
Fuel | 92 | 94 | |
Gas stored | 22 | 30 | |
Materials and supplies | 243 | 232 | |
Prepayments | 78 | 84 | |
Regulatory assets | 351 | 444 | |
Other current assets | [1] | 30 | 23 |
Total current assets | 1,285 | 1,429 | |
Deferred Debits and Other Assets: | |||
Regulatory assets | 3,094 | 3,107 | |
Affiliated receivables | 4 | 4 | |
Other | [1] | 339 | 268 |
Total deferred debits and other assets | 3,437 | 3,379 | |
Total assets | 15,907 | 15,857 | |
CAPITALIZATION AND LIABILITIES | |||
Common Stock - no par value | 4,088 | 4,088 | |
Retained earnings | 604 | 592 | |
Accumulated other comprehensive loss | (1) | (1) | |
Total common equity | 4,691 | 4,679 | |
Noncontrolling interest | 189 | 183 | |
Total equity | 4,880 | 4,862 | |
Long-term debt, net | 4,219 | 4,219 | |
Finance leases | 3 | 4 | |
Total long-term debt | 4,222 | 4,223 | |
Total capitalization | 9,102 | 9,085 | |
Current Liabilities: | |||
Short-term borrowings | 210 | 254 | |
Securities due within one year | 3 | 3 | |
Accounts payable | 135 | 180 | |
Affiliated and related party payables | 1,013 | 740 | |
Customer deposits and customer prepayments | 71 | 75 | |
Taxes accrued | 71 | 248 | |
Interest accrued | 81 | 79 | |
Regulatory liabilities | 233 | 205 | |
Other | 133 | 166 | |
Total current liabilities | 1,950 | 1,950 | |
Deferred Credits and Other Liabilities: | |||
Deferred income taxes and investment tax credits | 1,323 | 1,318 | |
Asset retirement obligations | 734 | 731 | |
Pension and other postretirement benefits | 114 | 115 | |
Regulatory liabilities | 2,598 | 2,579 | |
Other | 86 | 79 | |
Total deferred credits and other liabilities | 4,855 | 4,822 | |
Commitments and Contingencies | |||
Total capitalization and liabilities | 15,907 | 15,857 | |
Related Party | |||
Current Assets: | |||
Affiliated and related party | $ 3 | $ 4 | |
[1] See Note 12 for amounts attributable to affiliates. |
Consolidated Balance Sheets (_2
Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) shares in Millions, $ in Millions | Mar. 31, 2024 | Dec. 31, 2023 |
Utility plant, net | $ 10,907 | $ 10,778 |
Receivables, customer, allowance for uncollectible accounts | 8 | 6 |
Total current assets | 1,285 | 1,429 |
Total deferred debits and other assets | $ 3,437 | $ 3,379 |
Common stock, par value | $ 0 | $ 0 |
Common stock, shares outstanding | 40.3 | 40.3 |
Variable Interest Entity, Primary Beneficiary [Member] | ||
Utility plant, net | $ 788 | $ 773 |
Total current assets | 87 | 89 |
Total deferred debits and other assets | $ 26 | $ 26 |
Consolidated Statements of Comp
Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions | 3 Months Ended | ||
Mar. 31, 2024 | Mar. 31, 2023 | ||
Income Statement [Abstract] | |||
Operating Revenue | [1] | $ 775 | $ 759 |
Operating Expenses: | |||
Fuel used in electric generation | 145 | 150 | |
Purchased power | [1] | 10 | 7 |
Gas purchased for resale | 79 | 82 | |
Other operations and maintenance | 122 | 115 | |
Other operations and maintenance - affiliated suppliers | 41 | 41 | |
Depreciation and amortization | 136 | 129 | |
Other taxes | [1] | 78 | 78 |
Total operating expenses | 611 | 602 | |
Operating income | 164 | 157 | |
Other income (expense), net | 1 | 10 | |
Interest charges, net of AFUDC | [1] | 67 | 59 |
Income before income tax expense | 98 | 108 | |
Income tax expense | 18 | 11 | |
Net Income and Other Comprehensive Income | 80 | 97 | |
Comprehensive Income Attributable to Noncontrolling Interest | 6 | 5 | |
Comprehensive Income Available to Common Shareholder | $ 74 | $ 92 | |
[1] See Note 12 for amounts attributable to affiliates. |
Consolidated Statements of Co_2
Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Income Statement [Abstract] | ||
Allowance for funds used during construction | $ 4 | $ 4 |
Consolidated Statements of Cash
Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions | 3 Months Ended | ||
Mar. 31, 2024 | Mar. 31, 2023 | ||
Operating Activities | |||
Net income | $ 80 | $ 97 | |
Adjustments to reconcile net income to net cash provided by operating activities: | |||
Deferred income taxes, net | 5 | 5 | |
Depreciation and amortization | 136 | 129 | |
Amortization of nuclear fuel | 9 | 9 | |
Other adjustments | 0 | (7) | |
Changes in certain assets and liabilities: | |||
Receivables | 45 | 91 | |
Receivables - affiliated and related party | 1 | 1 | |
Inventories | (1) | 0 | |
Prepayments | 2 | 5 | |
Regulatory assets | 79 | 56 | |
Regulatory liabilities | 41 | (122) | |
Accounts payable | (18) | (87) | |
Accounts payable - affiliated and related party | 43 | 11 | |
Taxes accrued | (177) | (165) | |
Interest accrued | 2 | (7) | |
Pension and other postretirement benefits | (1) | 0 | |
Other assets and liabilities | (80) | 56 | |
Net cash provided by operating activities | 166 | 72 | |
Investing Activities | |||
Property additions and construction expenditures | (268) | (283) | |
Proceeds from investments and sales of assets | (13) | (8) | |
Purchase of investments | (5) | (4) | |
Other | 0 | 1 | |
Net cash used in investing activities | (286) | (294) | |
Financing Activities | |||
Dividend to parent | (62) | (50) | |
Short-term borrowings, net | (44) | 28 | |
Short-term borrowings - affiliated, net | 230 | 235 | |
Other | (1) | 1 | |
Net cash provided by financing activities | 123 | 214 | |
Net increase (decrease) in cash, restricted cash and equivalents | 3 | (8) | |
Cash, restricted cash and equivalents at beginning of period | [1] | 1 | 11 |
Cash, restricted cash and equivalents at end of period | [1] | 4 | 3 |
Significant noncash investing and financing activities: | |||
Accrued construction expenditures | [2] | $ 56 | $ 54 |
[1] At March 31, 2024, December 31, 2023, March 31, 2023 and December 31, 2022 there were no restricted cash and equivalent balances. See Note 10 for noncash investing activities related to the transfer of property associated with the settlement of litigation. |
Consolidated Statements of Ca_2
Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023 | Mar. 31, 2023 | Dec. 31, 2022 |
Statement of Cash Flows [Abstract] | ||||
Restricted cash and equivalents | $ 0 | $ 0 | $ 0 | $ 0 |
Consolidated Statements of Chan
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, 2022 | $ 4,666 | $ 4,088 | $ 418 | $ (2) | $ 162 |
Beginning balance (in shares) at Dec. 31, 2022 | 40 | ||||
Total comprehensive income available to common shareholder | 97 | 92 | 5 | ||
Dividend to parent | (50) | (50) | |||
Ending balance at Mar. 31, 2023 | 4,713 | $ 4,088 | 460 | (2) | 167 |
Ending balance (in shares) at Mar. 31, 2023 | 40 | ||||
Beginning balance at Dec. 31, 2023 | 4,862 | $ 4,088 | 592 | (1) | 183 |
Beginning balance (in shares) at Dec. 31, 2023 | 40 | ||||
Total comprehensive income available to common shareholder | 80 | 74 | 6 | ||
Dividend to parent | (62) | (62) | |||
Ending balance at Mar. 31, 2024 | $ 4,880 | $ 4,088 | $ 604 | $ (1) | $ 189 |
Ending balance (in shares) at Mar. 31, 2024 | 40 |
Pay vs Performance Disclosure
Pay vs Performance Disclosure - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Pay vs Performance Disclosure | ||
Net Income (Loss) | $ 74 | $ 92 |
Insider Trading Arrangements
Insider Trading Arrangements | 3 Months Ended |
Mar. 31, 2024 | |
Trading Arrangements, by Individual | |
Rule 10b5-1 Arrangement Adopted | false |
Non-Rule 10b5-1 Arrangement Adopted | false |
Rule 10b5-1 Arrangement Terminated | false |
Non-Rule 10b5-1 Arrangement Terminated | false |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 3 Months Ended |
Mar. 31, 2024 | |
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, 2023 for a description of GENCO and Fuel Company. 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 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, 2023 , except as follows. New Accounting Standards Climate-Related Disclosures In March 2024, the SEC issued guidance for climate-related disclosures. The guidance requires disclosure of the financial statement impacts of severe weather events and other natural conditions, including amounts capitalized or expensed as well as any associated recoveries. In addition, the guidance requires disclosure of amounts related to renewable energy credits or carbon offsets if utilized as a material component of plans to achieve climate-related targets or goals. This guidance, which is currently subject to a stay issued by the SEC, would be effective for the fiscal year beginning January 1, 2025. DESC expects this guidance to only impact its disclosures with no impacts to its results of operations, cash flows or financial condition. |
Rate and Other Regulatory Matte
Rate and Other Regulatory Matters | 3 Months Ended |
Mar. 31, 2024 | |
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, 2023. Electric Base Rate Case In March 2024, DESC filed its retail electric base rate case and schedules with the South Carolina Commission. DESC proposed a non-fuel, base rate increase of $ 295 million, partially offset by a net decrease in storm damage and DSM components of $ 4 million. If approved, the overall proposed rate increase of $ 291 million, or 12.59 %, would be effective on and after the first billing cycle of September 2024. 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 4.32 % based upon a fully-adjusted test period. The proposed rates would provide for an earned ROE of 1 0.60 % compared to the currently authorized ROE of 9.50 %. This matter is pending. 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 2024, DESC filed with the South Carolina Commission a proposal to decrease the total fuel cost component of retail electric rates. DESC’s proposed adjustment is designed to recover DESC’s current base fuel costs, including its existing under-collected balance, over the 12-month period beginning with the first billing cycle of May 2024. In addition, DESC proposed an increase to its variable environmental and avoided capacity cost component. The net effect is a proposed annual decrease of $ 315 million. In March 2024, DESC, the South Carolina Office of Regulatory Staff and another party of record filed a settlement agreement with the South Carolina Commission for approval to make certain adjustments to the February 2024 filing that would result in a net annual decrease of $ 316 million. In April 2024, the South Carolina Commission voted to approve the settlement agreement, with rates effective May 2024. Electric - Transmission Project In March 2024, DESC filed an application with the South Carolina Commission requesting approval of a CPCN to construct and operate the Church Creek - Charleston Transmission Line, comprised of a 7 mile 230 kV transmission line and associated facilities in Charleston County, South Carolina with an estimated total project cost of $ 40 million. This matter is pending. Electric – Other DESC has approval for a DSM rider through which it recovers expenditures related to its DSM programs. In January 2024, DESC filed an application with the South Carolina Commission seeking approval to recover $ 47 million of costs and net lost revenues associated with these programs, along with an incentive to invest in such programs. DESC requested that rates be effective with the first billing cycle of May 2024. In April 2024, the South Carolina Commission approved the request, effective with the first billing cycle of May 2024. 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 2024, DESC requested that the South Carolina Commission approve an adjustment to this rider to increase annual revenue by $ 9 million. In April 2024, the South Carolina Commission approved the request. 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 costs referenced herein, 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. March 31, December 31, (millions) 2024 2023 Regulatory assets: NND Project costs (1) $ 138 $ 138 AROs (2) 38 44 Deferred employee benefit plan costs (3) 7 11 Other unrecovered plant (4) 19 19 DSM programs (5) 22 22 Cost of fuel and purchased gas under-collections (6) 71 154 Other 56 56 Regulatory assets - current 351 444 NND Project costs (1) 1,915 1,949 AROs (2) 382 379 Deferred employee benefit plan costs (3) 120 118 Interest rate hedges (7) 168 168 Other unrecovered plant (4) 70 66 DSM programs (5) 46 46 Environmental remediation costs (8) 33 34 Deferred storm damage costs (9) 39 40 Deferred transmission operating costs (10) 73 74 Derivatives (11) 99 103 Other (12) 149 130 Regulatory assets - noncurrent 3,094 3,107 Total regulatory assets $ 3,445 $ 3,551 Regulatory liabilities: Monetization of guaranty settlement (13) $ 67 $ 67 Income taxes refundable through future rates (14) 37 37 Reserve for refunds to electric utility customers (15) 83 83 Derivatives (11) 15 12 Cost of fuel and purchased gas over-collections (6) 21 — Other 10 6 Regulatory liabilities - current 233 205 Monetization of guaranty settlement (13) 619 635 Income taxes refundable through future rates (14) 830 839 Asset removal costs (16) 640 633 Reserve for refunds to electric utility customers (15) 212 237 Derivatives (11) 296 229 Other 1 6 Regulatory liabilities - noncurrent 2,598 2,579 Total regulatory liabilities $ 2,831 $ 2,784 (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 . (2) Represents uncollected costs, including 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. (3) 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. (4) 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 depreciation 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 through 2033 . In addition, amounts include unrecovered costs of existing meters and equipment retired from service prior to being fully depreciated as part of the Advanced Metering Infrastructure project, which are being recovered through rates through 2028 . This amount also includes certain inventory and preliminary survey and investigation charges being amortized over five years related to the transition or conversion from coal to gas fired generation at certain facilities. (5) 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. (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) Represents the changes in fair value and payments made or received upon settlement of certain interest rate derivatives designated as cash flow hedges. The amounts recorded are expected to be amortized to interest expense over the lives of the underlying debt through 2065 . (8) 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 24 years. See Note 10 for additional information. (9) Represents storm restoration costs for which DESC expects to receive future recovery through customer rates over approximately 10 years pursuant to the settlement agreement approved in DESC’s retail electric base rate case. Unamortized amounts are included in rate base and are earning a current return. (10) Includes deferred depreciation and property taxes associated with certain transmission assets for which DESC expects recovery from customers through future rates over approximately 42 years pursuant to the settlement agreement approved in DESC’s retail electric base rate case. Unamortized amounts are included in rate base and earning a current return. See Note 12 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2023. (11) Represents changes in the fair value of derivatives, excluding separately presented interest rate hedges, that following settlement are expected to be recovered from or refunded to customers. (12) Various other regulatory assets are expected to be recovered through rates over varying periods through 2078 . (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 . (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 7 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2023 for additional 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. (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 that 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. |
Revenue Recognition
Revenue Recognition | 3 Months Ended |
Mar. 31, 2024 | |
Revenue from Contract with Customer [Abstract] | |
Revenue Recognition | 3. REVENUE RECOGNITION DESC has disaggregated operating revenues by customer class as follows: Three Months Ended March 31, 2024 2023 (millions) Electric Gas Electric Gas Customer class: Residential $ 283 $ 117 $ 262 $ 109 Commercial 188 41 187 42 Industrial 87 18 91 22 Other 28 6 36 4 Revenues from contracts with customers 586 182 576 177 Other revenues 7 — 6 — Total Operating Revenues $ 593 $ 182 $ 582 $ 177 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 $ 6 million and $ 7 million at March 31, 2024 and December 31, 2023, respectively. During the three months ended March 31, 2024 and 2023 , DESC recognized revenue of $ 3 million and $ 7 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. Balances and activity related to contract costs deferred as regulatory assets were as follows: Regulatory Assets (millions) March 31, 2024 December 31, 2023 Beginning balance $ 11 $ 9 Additional costs — 3 Amortization — ( 1 ) Ending balance $ 11 $ 11 |
Equity
Equity | 3 Months Ended |
Mar. 31, 2024 | |
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. 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, 2023 . |
Long-Term and Short-Term Debt
Long-Term and Short-Term Debt | 3 Months Ended |
Mar. 31, 2024 | |
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, which 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. Other than the items discussed below, there have been no significant changes from Note 6 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2023. At March 31, 2024, DESC’s share of commercial paper and letters of credit outstanding under its joint credit facility with Dominion Energy, was as follows: (millions) Maximum Facility Sub-Limit Outstanding Outstanding Joint revolving credit facility (1) $ 1,000 $ 210 $ — (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. A 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 March 31, 2024 , 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 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 2023, FERC granted DESC authority through March 2025 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. At March 31, 2024 , DESC had issued $ 210 million in commercial paper under its joint credit facility with Dominion Energy as disclosed above and had drawn on $ 371 million of its intercompany credit facility with Dominion Energy, as permitted by this FERC authorization. In addition, in 2023, FERC granted GENCO authority through March 2025 to issue short-term indebtedness not to exceed $ 200 million outstanding with maturity dates of one year or less. At March 31, 2024 , GENCO had drawn on $ 23 million of its intercompany credit facility with Dominion Energy, as permitted by this FERC authorization. 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 2024. DESC, GENCO and Fuel Company each have intercompany credit facilities with Dominion Energy with a maximum capacity of $ 900 million, $ 200 million and $ 400 million, respectively. At March 31, 2024 and December 31, 2023, DESC, GENCO and Fuel Company collectively had borrowings outstanding under these agreements totaling $ 672 million and $ 442 million, respectively, which are recorded in affiliated and related party payables in DESC’s Consolidated Balance Sheets. Interest charges associated with these agreements were $ 10 million and $ 13 million for the three months ended March 31, 2024 and 2023 , respectively. |
Income Taxes
Income Taxes | 3 Months Ended |
Mar. 31, 2024 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | 6. INCOME TAXES For continuing operations, including noncontrolling interests, the statutory U.S. federal income tax rate reconciles to DESC’s effective income tax rate as follows: Three Months Ended March 31, 2024 2023 U.S. statutory rate 21.0 % 21.0 % Increases (reductions) resulting from: State taxes, net of federal benefit 3.9 4.1 Reversal of excess deferred income taxes ( 5.3 ) ( 4.7 ) Allowance for equity funds used during construction ( 0.7 ) — Settlements of uncertain tax positions — ( 9.9 ) Other, net — ( 0.1 ) Effective tax rate 18.9 % 10.4 % As of March 31, 2024, there have been no material changes in DESC’s unrecognized tax benefits or possible changes that could reasonably be expected to occur during the next twelve months. See Note 7 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2023, for a discussion of these unrecognized tax benefits. For the three months ended March 31, 2023, DESC’s effective tax rate reflects an income tax benefit of $ 11 million from the effective settlement of a position that management believed was reasonably possible to occur. |
Derivative Financial Instrument
Derivative Financial Instruments | 3 Months Ended |
Mar. 31, 2024 | |
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, 2023. See Note 8 for further information about fair value measurements and associated valuation methods for derivatives. 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 March 31, 2024 and December 31, 2023 , DESC would have been required to post $ 2 million and $ 4 million, respectively, of additional collateral to its counterparties. The collateral that would be required to be posted includes the impacts of any offsetting asset positions and any amounts already posted for derivatives and non-derivative contracts per contractual terms. DESC had no t posted any collateral at March 31, 2024 and December 31, 2023 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 as of March 31, 2024 and December 31, 2023 was $ 2 million and $ 4 million, respectively, which does not include the impact of any offsetting asset positions. 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: March 31, 2024 December 31, 2023 Gross Amounts Not Offset in the Consolidated Gross Amounts Not Offset in the Consolidated (millions) Gross (1) Financial Cash Net Gross (1) Financial Cash Net Interest rate contracts: Over-the-counter $ 1 $ — $ — $ 1 $ — $ — $ — $ — Commodity contracts: Over-the-counter 9 — — 9 — — — — Total derivatives $ 10 $ — $ — $ 10 $ — $ — $ — $ — (1) Excludes derivative assets of $ 245 million and $ 176 million at March 31, 2024 and December 31, 2023, respectively, which are not subject to master netting or similar arrangements. March 31, 2024 December 31, 2023 Gross Amounts Not Offset in the Consolidated Gross Amounts Not Offset in the Consolidated (millions) Gross (1) Financial Cash Net Gross (1) Financial Cash Net Interest rate contracts: Over-the-counter $ 2 $ — $ — $ 2 $ 4 $ — $ — $ 4 Total derivatives $ 2 $ — $ — $ 2 $ 4 $ — $ — $ 4 (1) DESC did no t have any derivative liabilities at March 31, 2024 and December 31, 2023, respectively, which were not subject to master netting or similar arrangements. Volumes The following table presents the volume of derivative activity at March 31, 2024. These volumes are based on open derivative positions and represent the combined absolute value of their long and short positions. Current Noncurrent Natural Gas (bcf): Basis (1) 24 — Electricity (MWh in millions): Fixed price 2 23 Interest rate (2) (in millions) $ — $ 71 (1) Includes options. (2) 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 - Fair Value - Total Fair Value At March 31, 2024 ASSETS Current Assets Commodity $ — $ 19 $ 19 Total current derivative assets (1) — 19 19 Noncurrent Assets Commodity — 235 235 Interest rate — 1 1 Total noncurrent derivative assets (2) — 236 236 Total derivative assets $ — $ 255 $ 255 LIABILITIES Noncurrent Liabilities Interest rate — 2 2 Total noncurrent derivative liabilities (3) — 2 2 Total derivative liabilities $ — $ 2 $ 2 At December 31, 2023 ASSETS Current Assets Commodity $ — $ 9 $ 9 Total current derivative assets (1) — 9 9 Noncurrent Assets Commodity — 167 167 Interest rate — — — Total noncurrent derivative assets (2) — 167 167 Total derivative assets $ — $ 176 $ 176 LIABILITIES Noncurrent Liabilities Interest rate — 4 4 Total noncurrent derivative liabilities (3) — 4 4 Total derivative liabilities $ — $ 4 $ 4 (1) Current derivative assets are presented in other current assets in DESC’s Consolidated Balance Sheets. (2) Noncurrent derivative assets are presented in other deferred debits and other assets in DESC’s Consolidated Balance Sheets. (3) Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in DESC’s 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: Derivatives in Cash Flow Hedging Relationships (millions) Increase (Decrease) in Derivatives Subject to Regulatory Treatment (1) Three Months Ended March 31, 2024 2023 Derivative type and location of gains (losses): Interest rate $ — $ ( 1 ) Total $ — $ ( 1 ) (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. Derivatives Not Designated as Hedging Instruments (millions) Amount of Gain (Loss) Recognized in Income on Derivatives (1) Three Months Ended March 31, 2024 2023 Derivative type and location of gains (losses): Commodity: Purchased power $ ( 2 ) $ 1 Interest rate: Interest charges ( 1 ) — Total $ ( 3 ) $ 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. |
Fair Value Measurements, Includ
Fair Value Measurements, Including Derivatives | 3 Months Ended |
Mar. 31, 2024 | |
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 2 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2023. See Note 7 in this report for further information about DESC’s derivatives and hedge accounting activities. The following table presents DESC’s quantitative information about Level 3 fair value measurements at March 31, 2024. The range and weighted average are presented in dollars for market price inputs and percentages for price volatility. Fair Value Valuation Techniques Unobservable Input Range Weighted (1) Assets Physical forwards: Electricity $ 246 Discounted cash flow Market price (per MWh) (3) 24 - 102 51 Physical options: Natural gas (2) $ 7 Option model Market price (per Dth) (3) 1 - 3 2 Price volatility (4) 10 %- 51 % 34 % Total assets $ 253 (1) Averages weighted by volume. (2) Includes basis. (3) Represents market prices beyond defined terms for Levels 1 and 2. (4) Represents volatilities unrepresented in published markets. 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) Price volatility Buy Increase (decrease) Gain (loss) Price volatility Sell Increase (decrease) Loss (gain) Recurring Fair Value Measurements The following table presents DESC’s assets and 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 March 31, 2024 Assets Commodity $ — $ 1 $ 253 $ 254 Interest rate — 1 — 1 Total assets $ — $ 2 $ 253 $ 255 Liabilities Interest rate $ — $ 2 $ — $ 2 Total liabilities $ — $ 2 $ — $ 2 At December 31, 2023 Assets Commodity $ — $ — $ 176 $ 176 Interest rate — — — — Total assets $ — $ — $ 176 $ 176 Liabilities Interest rate $ — $ 4 $ — $ 4 Total liabilities $ — $ 4 $ — $ 4 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. Three Months Ended March 31, 2024 2023 (millions) Beginning balance $ 176 $ 251 Total realized and unrealized gains (losses): Included in earnings: Purchased power ( 2 ) 1 Included in regulatory assets/liabilities 70 ( 63 ) Settlements 2 ( 1 ) Purchases 7 — Ending balance $ 253 $ 188 There are no unrealized gains and losses included in earnings in the Level 3 fair value category related to assets/liabilities still held at the reporting date for the three months ended March 31, 2024 and 2023. 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: March 31, 2024 December 31, 2023 (millions) Carrying Amount Estimated Fair Value (1) Carrying Amount Estimated Fair Value (1) Long-term debt (2) $ 4,219 $ 4,221 $ 4,219 $ 4,301 Affiliated long-term debt (3) 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, if any, presented in securities due within one year and amounts which represent the unamortized debt issuance costs and discount or premium. (3) Carrying amount includes current portions presented in affiliated and related party payables. |
Employee Benefit Plans
Employee Benefit Plans | 3 Months Ended |
Mar. 31, 2024 | |
Retirement Benefits [Abstract] | |
Employee Benefit Plans | 9. EMPLOYEE BENEFIT PLANS In DESC’s Consolidated Statements of Comprehensive Income, the service cost component of net periodic benefit (credit) cost is reflected in other operations and maintenance expense with the non-service cost components reflected in other income. Components of net periodic benefit cost (credit) recorded by DESC were as follows: (millions) Pension Benefits Other Postretirement Benefits Three Months Ended March 31, 2024 2023 2024 2023 Service cost $ 2 $ 2 $ — $ — Interest cost 8 8 2 2 Expected return on assets ( 9 ) ( 8 ) — — Amortization of actuarial losses 2 3 ( 1 ) ( 1 ) Net periodic benefit cost $ 3 $ 5 $ 1 $ 1 During the three months ended March 31, 2024 , DESC made no contributions to its pension trust. DESC expects to make $ 8 million of minimum required contributions to its qualified pension plan in 2024 and expects to receive reimbursement for such contributions from Santee Cooper. In April 2024, DESC made $ 1 million of contributions to its qualified pension plan. 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. |
Commitments And Contingencies
Commitments And Contingencies | 3 Months Ended |
Mar. 31, 2024 | |
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. DESC maintains various insurance programs, including general liability insurance coverage which provides coverage for personal injury or wrongful death cases. 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. During the three months ended March 31, 2024, DESC recorded $ 6 million of charges in aggregate for various personal injury or wrongful death cases. 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 continually monitors and evaluates its current and projected emission levels and strives to comply with all state and federal regulations regarding those emissions. DESC participates in the SO 2 and NO x emission allowance programs with respect to coal plant emissions and also has constructed additional pollution control equipment at its 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. 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. In October 2021, the U.S. Supreme Court agreed to hear a challenge of the U.S. Court of Appeals for the D.C. Circuit’s decision on the ACE Rule. In June 2022, the U.S. Supreme Court reversed the D.C. Circuit’s decision on the ACE Rule and remanded the case back to the D.C. Circuit. In May 2023, the EPA proposed to repeal the ACE Rule as part of a package of proposed rules addressing CO 2 emissions from new and existing fossil fuel-fired electric generating units. Until the EPA takes final action on this proposed rulemaking, DESC cannot predict an impact to its 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 CO 2 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. 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, technological, and cost 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 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 potentially 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 manufactured gas plant 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. In the fourth quarter of 2023, DESC completed the majority of remediation activities at one site. DESC anticipates the remaining activities at that site will be completed by 2025 at an estimated cost of $ 5 million, after which the site will continue to incur ongoing maintenance and monitoring obligations. DESC expects to recover costs arising from the remediation work at all four sites through rate recovery mechanisms and as of March 31, 2024 , deferred amounts, net of amounts previously recovered through rates and insurance settlements, totaled $ 34 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 three 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. In May 2023, the EPA released a proposed rule addressing one of the previously remanded provisions of the CCR rule to regulate inactive surface impoundments located at retired generating stations that contained CCR and liquids after October 2015, and certain other inactive or previously closed surface impoundments, landfills or other areas that contain accumulations of CCR. Until the EPA ultimately takes final action on this rulemaking, DESC is unable to predict whether or to what extent the new rules will ultimately require additional controls. 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. Claims and Litigation The following describes certain legal proceedings involving DESC relating primarily to events occurring before closing of the SCANA Combination. Matters Fully Resolved Prior to 2024 Impacting the Consolidated Financial Statements 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 May 2022, Dominion Energy issued an additional 0.9 million shares of its common stock to partially satisfy DESC’s remaining obligation under the settlement agreement. In June 2022, DESC requested approval from the South Carolina Commission to transfer certain real estate with a total settlement value of $ 51 million to satisfy its remaining obligation under the settlement agreement. In July 2022, the South Carolina Commission voted to approve the request and issued its final order in August 2022. In September 2022, DESC transferred certain non-utility property with a fair value of $ 28 million to the SCDOR under the settlement agreement. In December 2022, DESC transferred additional utility property with a fair value of $ 3 million to the SCDOR. In October 2022, DESC filed for approval to transfer the remaining real estate with FERC which was received in November 2022. In March 2023, DESC transferred utility property with a fair value of $ 10 million to the SCDOR resulting in a gain of $ 9 million ($ 7 million after-tax), recorded in other income, net in DESC ’ s Consolidated Statements of Comprehensive Income for the three months ended March 31, 2023. In June 2023, DESC transferred the remaining utility property with a fair value of $ 11 million to the SCDOR. In July 2023, DESC made a less than $ 1 million cash payment to the SCDOR to fully satisfy its remaining obligation, including applicable interest, under the settlement agreement. Nuclear Operations Other than the items discussed below, there have been no significant changes regarding DESC’s nuclear insurance and spent nuclear fuel as described in Note 12 to the Consolidated Financial Statements in the DESC’s Annual Report on Form 10-K for the year ended December 31, 2023. During the first quarter of 2024, the total liability protection per nuclear incident available to all participants in the Secondary Financial Protection Program increased from $ 16.2 billion to $ 16.3 billion. This increase does not impact DESC’s responsibility per active unit under the Price-Anderson Amendments Act of 1988. Additionally, Dominion Energy increased the amount of coverage purchased from commercial insurance pools for Summer from $ 450 million to $ 500 million with the remainder provided through the mandatory industry retrospective rating plan. Surety Bonds At March 31, 2024, DESC had purchased $ 24 million of surety bonds. Under the terms of surety bonds, DESC is obligated to indemnify the respective surety bond company for any amounts paid. |
Operating Segments
Operating Segments | 3 Months Ended |
Mar. 31, 2024 | |
Segment Reporting [Abstract] | |
Operating Segments | 11. OPERATING SEGMENTS The Corporate and Other segment primarily includes specific items attributable to DESC’s 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 three months ended March 31, 2024 and 2023, DESC reported an insignificant amount of specific items in the Corporate and Other segment. (millions) External Comprehensive Three Months Ended March 31, 2024 Dominion Energy South Carolina $ 775 $ 75 Corporate and Other — ( 1 ) Consolidated total $ 775 $ 74 Three Months Ended March 31, 2023 Dominion Energy South Carolina $ 759 $ 86 Corporate and Other — 6 Consolidated total $ 759 $ 92 |
Affiliated and Related Party Tr
Affiliated and Related Party Transactions | 3 Months Ended |
Mar. 31, 2024 | |
Related Party Transactions [Abstract] | |
Affiliated and Related Party Transactions | 12. AFFILIATED AND RELATED PARTY TRANSACTIONS DES, on behalf of itself and its parent company, provides the following services to DESC, which are 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. Costs for these services include amounts capitalized. Amounts expensed are primarily recorded in other operations and maintenance - affiliated suppliers and other income, net in the Consolidated Statements of Comprehensive Income. DESC transacts with affiliates for certain quantities of electricity in the ordinary course of business. DESC also enters into certain commodity derivative contracts with affiliates. DESC uses these contracts, which are principally comprised of forward commodity purchases, to manage commodity price risks associated with purchases of electricity. See Note 7 for additional information. Three Months Ended (millions) 2024 2023 Direct and allocated costs from DES (1) $ 53 $ 57 Operating Revenues - Electric from sales to affiliate 1 1 Operating Expenses - Other taxes from affiliate 3 3 Purchases of electricity from solar affiliates 1 2 (1) Includes capitalized expenditures of $ 12 million and $ 16 million for the three months ended March 31, 2024 and 2023 , respectively. (millions) March 31, 2024 December 31, 2023 Payable to DES 41 18 Payable to SCANA Corporation 7 7 Payable to Public Service Company of North Carolina, Incorporated 12 13 Derivative assets with affiliates (1) 42 33 (1) Includes amounts recorded in other current assets of $ 2 million as of both March 31, 2024 and December 31, 2023 and amounts recorded in other deferred debits and other assets of $ 40 million and $ 31 million as of March 31, 2024 and December 31, 2023 , respectively. Borrowings from an affiliate are described in Note 5. |
Other Income, Net
Other Income, Net | 3 Months Ended |
Mar. 31, 2024 | |
Income Statement [Abstract] | |
Other Income, Net | 13. OTHER INCOME, NET Components of other income, net are as follows: Three Months Ended March 31, (millions) 2024 2023 Other income $ 2 $ 2 Gains on sales of assets (1) 1 10 Other expense ( 5 ) ( 2 ) Allowance for equity funds used during construction 3 — Other income, net $ 1 $ 10 (1) Includes amounts recognized in 2023 in connection with the transfer of property to satisfy litigation. See Note 10 for additional information. |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 3 Months Ended |
Mar. 31, 2024 | |
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, 2023 for a description of GENCO and Fuel Company. 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 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, 2023 , except as follows. |
New Accounting Standards | New Accounting Standards Climate-Related Disclosures In March 2024, the SEC issued guidance for climate-related disclosures. The guidance requires disclosure of the financial statement impacts of severe weather events and other natural conditions, including amounts capitalized or expensed as well as any associated recoveries. In addition, the guidance requires disclosure of amounts related to renewable energy credits or carbon offsets if utilized as a material component of plans to achieve climate-related targets or goals. This guidance, which is currently subject to a stay issued by the SEC, would be effective for the fiscal year beginning January 1, 2025. DESC expects this guidance to only impact its disclosures with no impacts to its results of operations, cash flows or financial condition. |
Rate and Other Regulatory Mat_2
Rate and Other Regulatory Matters (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Regulated Operations [Abstract] | |
Schedule of Regulatory Assets and Liabilities | March 31, December 31, (millions) 2024 2023 Regulatory assets: NND Project costs (1) $ 138 $ 138 AROs (2) 38 44 Deferred employee benefit plan costs (3) 7 11 Other unrecovered plant (4) 19 19 DSM programs (5) 22 22 Cost of fuel and purchased gas under-collections (6) 71 154 Other 56 56 Regulatory assets - current 351 444 NND Project costs (1) 1,915 1,949 AROs (2) 382 379 Deferred employee benefit plan costs (3) 120 118 Interest rate hedges (7) 168 168 Other unrecovered plant (4) 70 66 DSM programs (5) 46 46 Environmental remediation costs (8) 33 34 Deferred storm damage costs (9) 39 40 Deferred transmission operating costs (10) 73 74 Derivatives (11) 99 103 Other (12) 149 130 Regulatory assets - noncurrent 3,094 3,107 Total regulatory assets $ 3,445 $ 3,551 Regulatory liabilities: Monetization of guaranty settlement (13) $ 67 $ 67 Income taxes refundable through future rates (14) 37 37 Reserve for refunds to electric utility customers (15) 83 83 Derivatives (11) 15 12 Cost of fuel and purchased gas over-collections (6) 21 — Other 10 6 Regulatory liabilities - current 233 205 Monetization of guaranty settlement (13) 619 635 Income taxes refundable through future rates (14) 830 839 Asset removal costs (16) 640 633 Reserve for refunds to electric utility customers (15) 212 237 Derivatives (11) 296 229 Other 1 6 Regulatory liabilities - noncurrent 2,598 2,579 Total regulatory liabilities $ 2,831 $ 2,784 (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 . (2) Represents uncollected costs, including 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. (3) 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. (4) 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 depreciation 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 through 2033 . In addition, amounts include unrecovered costs of existing meters and equipment retired from service prior to being fully depreciated as part of the Advanced Metering Infrastructure project, which are being recovered through rates through 2028 . This amount also includes certain inventory and preliminary survey and investigation charges being amortized over five years related to the transition or conversion from coal to gas fired generation at certain facilities. (5) 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. (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) Represents the changes in fair value and payments made or received upon settlement of certain interest rate derivatives designated as cash flow hedges. The amounts recorded are expected to be amortized to interest expense over the lives of the underlying debt through 2065 . (8) 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 24 years. See Note 10 for additional information. (9) Represents storm restoration costs for which DESC expects to receive future recovery through customer rates over approximately 10 years pursuant to the settlement agreement approved in DESC’s retail electric base rate case. Unamortized amounts are included in rate base and are earning a current return. (10) Includes deferred depreciation and property taxes associated with certain transmission assets for which DESC expects recovery from customers through future rates over approximately 42 years pursuant to the settlement agreement approved in DESC’s retail electric base rate case. Unamortized amounts are included in rate base and earning a current return. See Note 12 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2023. (11) Represents changes in the fair value of derivatives, excluding separately presented interest rate hedges, that following settlement are expected to be recovered from or refunded to customers. (12) Various other regulatory assets are expected to be recovered through rates over varying periods through 2078 . (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 . (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 7 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2023 for additional 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. (16) Represents estimated net collections through depreciation rates of amounts to be expended for the removal of assets in the future. |
Revenue Recognition (Tables)
Revenue Recognition (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Revenue from Contract with Customer [Abstract] | |
Disaggregation of Revenue | DESC has disaggregated operating revenues by customer class as follows: Three Months Ended March 31, 2024 2023 (millions) Electric Gas Electric Gas Customer class: Residential $ 283 $ 117 $ 262 $ 109 Commercial 188 41 187 42 Industrial 87 18 91 22 Other 28 6 36 4 Revenues from contracts with customers 586 182 576 177 Other revenues 7 — 6 — Total Operating Revenues $ 593 $ 182 $ 582 $ 177 |
Balance and Activity Related to Contract Costs Deferred as Regulatory Assets | Balances and activity related to contract costs deferred as regulatory assets were as follows: Regulatory Assets (millions) March 31, 2024 December 31, 2023 Beginning balance $ 11 $ 9 Additional costs — 3 Amortization — ( 1 ) Ending balance $ 11 $ 11 |
Long-Term and Short-Term Debt (
Long-Term and Short-Term Debt (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Debt Disclosure [Abstract] | |
Schedule of Line of Credit Facilities | At March 31, 2024, DESC’s share of commercial paper and letters of credit outstanding under its joint credit facility with Dominion Energy, was as follows: (millions) Maximum Facility Sub-Limit Outstanding Outstanding Joint revolving credit facility (1) $ 1,000 $ 210 $ — (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. A 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 March 31, 2024 , 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 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. |
Income Taxes (Tables)
Income Taxes (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Income Tax Disclosure [Abstract] | |
Schedule of Effective Income Tax Rate Reconciliation | Three Months Ended March 31, 2024 2023 U.S. statutory rate 21.0 % 21.0 % Increases (reductions) resulting from: State taxes, net of federal benefit 3.9 4.1 Reversal of excess deferred income taxes ( 5.3 ) ( 4.7 ) Allowance for equity funds used during construction ( 0.7 ) — Settlements of uncertain tax positions — ( 9.9 ) Other, net — ( 0.1 ) Effective tax rate 18.9 % 10.4 % |
Derivative Financial Instrume_2
Derivative Financial Instruments (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Derivative Instruments and Hedging Activities Disclosure [Abstract] | |
Offsetting Assets | 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: March 31, 2024 December 31, 2023 Gross Amounts Not Offset in the Consolidated Gross Amounts Not Offset in the Consolidated (millions) Gross (1) Financial Cash Net Gross (1) Financial Cash Net Interest rate contracts: Over-the-counter $ 1 $ — $ — $ 1 $ — $ — $ — $ — Commodity contracts: Over-the-counter 9 — — 9 — — — — Total derivatives $ 10 $ — $ — $ 10 $ — $ — $ — $ — (1) Excludes derivative assets of $ 245 million and $ 176 million at March 31, 2024 and December 31, 2023, respectively, which are not subject to master netting or similar arrangements. |
Offsetting Liabilities | March 31, 2024 December 31, 2023 Gross Amounts Not Offset in the Consolidated Gross Amounts Not Offset in the Consolidated (millions) Gross (1) Financial Cash Net Gross (1) Financial Cash Net Interest rate contracts: Over-the-counter $ 2 $ — $ — $ 2 $ 4 $ — $ — $ 4 Total derivatives $ 2 $ — $ — $ 2 $ 4 $ — $ — $ 4 (1) DESC did no t have any derivative liabilities at March 31, 2024 and December 31, 2023, respectively, which were not subject to master netting or similar arrangements. |
Schedule of Volume of Derivative Activity | The following table presents the volume of derivative activity at March 31, 2024. These volumes are based on open derivative positions and represent the combined absolute value of their long and short positions. Current Noncurrent Natural Gas (bcf): Basis (1) 24 — Electricity (MWh in millions): Fixed price 2 23 Interest rate (2) (in millions) $ — $ 71 (1) Includes options. (2) 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 - Fair Value - Total Fair Value At March 31, 2024 ASSETS Current Assets Commodity $ — $ 19 $ 19 Total current derivative assets (1) — 19 19 Noncurrent Assets Commodity — 235 235 Interest rate — 1 1 Total noncurrent derivative assets (2) — 236 236 Total derivative assets $ — $ 255 $ 255 LIABILITIES Noncurrent Liabilities Interest rate — 2 2 Total noncurrent derivative liabilities (3) — 2 2 Total derivative liabilities $ — $ 2 $ 2 At December 31, 2023 ASSETS Current Assets Commodity $ — $ 9 $ 9 Total current derivative assets (1) — 9 9 Noncurrent Assets Commodity — 167 167 Interest rate — — — Total noncurrent derivative assets (2) — 167 167 Total derivative assets $ — $ 176 $ 176 LIABILITIES Noncurrent Liabilities Interest rate — 4 4 Total noncurrent derivative liabilities (3) — 4 4 Total derivative liabilities $ — $ 4 $ 4 (1) Current derivative assets are presented in other current assets in DESC’s Consolidated Balance Sheets. (2) Noncurrent derivative assets are presented in other deferred debits and other assets in DESC’s Consolidated Balance Sheets. (3) Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in DESC’s 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: Derivatives in Cash Flow Hedging Relationships (millions) Increase (Decrease) in Derivatives Subject to Regulatory Treatment (1) Three Months Ended March 31, 2024 2023 Derivative type and location of gains (losses): Interest rate $ — $ ( 1 ) Total $ — $ ( 1 ) (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. |
Derivatives Not Designated as Hedging Instruments | Derivatives Not Designated as Hedging Instruments (millions) Amount of Gain (Loss) Recognized in Income on Derivatives (1) Three Months Ended March 31, 2024 2023 Derivative type and location of gains (losses): Commodity: Purchased power $ ( 2 ) $ 1 Interest rate: Interest charges ( 1 ) — Total $ ( 3 ) $ 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. |
Fair Value Measurements, Incl_2
Fair Value Measurements, Including Derivatives (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
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 March 31, 2024. The range and weighted average are presented in dollars for market price inputs and percentages for price volatility. Fair Value Valuation Techniques Unobservable Input Range Weighted (1) Assets Physical forwards: Electricity $ 246 Discounted cash flow Market price (per MWh) (3) 24 - 102 51 Physical options: Natural gas (2) $ 7 Option model Market price (per Dth) (3) 1 - 3 2 Price volatility (4) 10 %- 51 % 34 % Total assets $ 253 (1) Averages weighted by volume. (2) Includes basis. (3) Represents market prices beyond defined terms for Levels 1 and 2. (4) Represents volatilities unrepresented in published markets. |
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) Price volatility Buy Increase (decrease) Gain (loss) Price volatility Sell Increase (decrease) Loss (gain) |
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis | The following table presents DESC’s assets and 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 March 31, 2024 Assets Commodity $ — $ 1 $ 253 $ 254 Interest rate — 1 — 1 Total assets $ — $ 2 $ 253 $ 255 Liabilities Interest rate $ — $ 2 $ — $ 2 Total liabilities $ — $ 2 $ — $ 2 At December 31, 2023 Assets Commodity $ — $ — $ 176 $ 176 Interest rate — — — — Total assets $ — $ — $ 176 $ 176 Liabilities Interest rate $ — $ 4 $ — $ 4 Total liabilities $ — $ 4 $ — $ 4 |
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis and included in Level 3 | 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. Three Months Ended March 31, 2024 2023 (millions) Beginning balance $ 176 $ 251 Total realized and unrealized gains (losses): Included in earnings: Purchased power ( 2 ) 1 Included in regulatory assets/liabilities 70 ( 63 ) Settlements 2 ( 1 ) Purchases 7 — Ending balance $ 253 $ 188 |
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: March 31, 2024 December 31, 2023 (millions) Carrying Amount Estimated Fair Value (1) Carrying Amount Estimated Fair Value (1) Long-term debt (2) $ 4,219 $ 4,221 $ 4,219 $ 4,301 Affiliated long-term debt (3) 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, if any, presented in securities due within one year and amounts which represent the unamortized debt issuance costs and discount or premium. (3) Carrying amount includes current portions presented in affiliated and related party payables. |
Employee Benefit Plans (Tables)
Employee Benefit Plans (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Retirement Benefits [Abstract] | |
Components of Net Periodic Benefit Cost (Credit) | (millions) Pension Benefits Other Postretirement Benefits Three Months Ended March 31, 2024 2023 2024 2023 Service cost $ 2 $ 2 $ — $ — Interest cost 8 8 2 2 Expected return on assets ( 9 ) ( 8 ) — — Amortization of actuarial losses 2 3 ( 1 ) ( 1 ) Net periodic benefit cost $ 3 $ 5 $ 1 $ 1 |
Operating Segments (Tables)
Operating Segments (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Segment Reporting [Abstract] | |
Schedule of Segment Reporting Information, by Segment | (millions) External Comprehensive Three Months Ended March 31, 2024 Dominion Energy South Carolina $ 775 $ 75 Corporate and Other — ( 1 ) Consolidated total $ 775 $ 74 Three Months Ended March 31, 2023 Dominion Energy South Carolina $ 759 $ 86 Corporate and Other — 6 Consolidated total $ 759 $ 92 |
Affiliated and Related Party _2
Affiliated and Related Party Transactions (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Related Party Transactions [Abstract] | |
Schedule of Affiliated Transactions | Amounts expensed are primarily recorded in other operations and maintenance - affiliated suppliers and other income, net in the Consolidated Statements of Comprehensive Income. Three Months Ended (millions) 2024 2023 Direct and allocated costs from DES (1) $ 53 $ 57 Operating Revenues - Electric from sales to affiliate 1 1 Operating Expenses - Other taxes from affiliate 3 3 Purchases of electricity from solar affiliates 1 2 (1) Includes capitalized expenditures of $ 12 million and $ 16 million for the three months ended March 31, 2024 and 2023 , respectively. |
Schedule of Affiliated Transactions | (millions) March 31, 2024 December 31, 2023 Payable to DES 41 18 Payable to SCANA Corporation 7 7 Payable to Public Service Company of North Carolina, Incorporated 12 13 Derivative assets with affiliates (1) 42 33 (1) Includes amounts recorded in other current assets of $ 2 million as of both March 31, 2024 and December 31, 2023 and amounts recorded in other deferred debits and other assets of $ 40 million and $ 31 million as of March 31, 2024 and December 31, 2023 , respectively. |
Other Income, Net (Tables)
Other Income, Net (Tables) | 3 Months Ended |
Mar. 31, 2024 | |
Income Statement [Abstract] | |
Components of Other Income, Net | Components of other income, net are as follows: Three Months Ended March 31, (millions) 2024 2023 Other income $ 2 $ 2 Gains on sales of assets (1) 1 10 Other expense ( 5 ) ( 2 ) Allowance for equity funds used during construction 3 — Other income, net $ 1 $ 10 (1) Includes amounts recognized in 2023 in connection with the transfer of property to satisfy litigation. See Note 10 for additional information. |
Rate and Other Regulatory Mat_3
Rate and Other Regulatory Matters (Narrative) (Detail) $ in Millions | 1 Months Ended | 3 Months Ended | ||
Mar. 31, 2024 USD ($) mi kV | Feb. 29, 2024 USD ($) | Jan. 31, 2024 USD ($) | Mar. 31, 2024 USD ($) | |
Rate And Other Regulatory Matters [Line Items] | ||||
Miles of Lines | mi | 7 | |||
Type of Line | kV | 230 | |||
Estimated electric transmission project cost | $ 40 | |||
Regulatory asset recovery assessment end period | 2078 | |||
Dominion Energy South Carolina, Inc. [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
Storm restoration recovery period | 10 years | |||
Electric Base Rate Case [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
Amount of Increase in proposed non fuel base rate | 295 | |||
Decrease in storm damage and DSM components | 4 | |||
Increase in proposed base rate amount | $ 291 | |||
Increase in proposed base rate percentage | 12.59% | |||
Percentage of current authorized earned ROE | 9.50% | |||
Percentage of earned return on equity | 4.32% | |||
Percentage of earned return on equity proposed rate | 0.60% | |||
Electric - Cost of Fuel [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
Proposed South Carolina Commission Order for Decrease of Total Fuel Cost Component of Retail Electric Rates to produce a projected under-recovery | $ 315 | |||
South Carolina Commission Order for Increase/Decrease of Total Fuel Cost Component of Retail Electric Rates to produce a projected under-recovery | $ 316 | $ 316 | ||
Reserve For Refunds To Electric Utility Customers [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
Electric service customers recovery period | 11 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 | 2065 | |||
Monetization Of Guaranty Settlement [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
Electric service customers recovery period | 20 years | |||
End period for recovery | Dec. 31, 2039 | |||
Income Taxes Refundable Through Future Rates [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
Remaining lives of related property period | 85 years | |||
NND Project Costs [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
Electric service customers recovery period | 20 years | |||
End period for recovery | Dec. 31, 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 | 2033 | |||
Advanced Metering Infrastructure Project [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
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 | 3 years | ||
Asset Retirement Obligation Costs [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
Recovery period of regulatory asset | 105 years | 105 years | ||
Environmental Remediation Costs [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
Recovery period of regulatory asset | 24 years | 24 years | ||
Deferred Transmission Operating Costs [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
Recovery period of regulatory asset | 42 years | 42 years | ||
Rider D S M [Member] | Electric - Other [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
South Carolina Commission Order, Annual DSM Program Rate Rider Recovery Amount | $ 47 | |||
South Carolina Commission [Member] | Electric - Other [Member] | ||||
Rate And Other Regulatory Matters [Line Items] | ||||
Annual increase (decrease) in pension cost rider | $ 9 |
Rate and Other Regulatory Mat_4
Rate and Other Regulatory Matters (Schedule of Regulatory Assets) (Detail) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023 | |
Regulatory Assets | |||
Regulatory assets, current | $ 351 | $ 444 | |
Regulatory assets, noncurrent | 3,094 | 3,107 | |
Total regulatory assets | 3,445 | 3,551 | |
NND Project Costs [Member] | |||
Regulatory Assets | |||
Regulatory assets, current | [1] | 138 | 138 |
Regulatory assets, noncurrent | [1] | 1,915 | 1,949 |
Deferred Employee Benefit Plan Costs [Member] | |||
Regulatory Assets | |||
Regulatory assets, current | [2] | 7 | 11 |
Regulatory assets, noncurrent | [2] | 120 | 118 |
Interest Rate Hedges [Member] | |||
Regulatory Assets | |||
Regulatory assets, noncurrent | [3] | 168 | 168 |
Other Unrecovered Plant [Member] | |||
Regulatory Assets | |||
Regulatory assets, current | [4] | 19 | 19 |
Regulatory assets, noncurrent | [4] | 70 | 66 |
Demand Side Management Programs [Member] | |||
Regulatory Assets | |||
Regulatory assets, current | [5] | 22 | 22 |
Regulatory assets, noncurrent | [5] | 46 | 46 |
Other Regulatory Assets [Member] | |||
Regulatory Assets | |||
Regulatory assets, current | 56 | 56 | |
Regulatory assets, noncurrent | [6] | 149 | 130 |
Cost of Fuel and Purchased Gas Under-Collections [Member] | |||
Regulatory Assets | |||
Regulatory assets, current | [7] | 71 | 154 |
Asset Retirement Obligation Costs [Member] | |||
Regulatory Assets | |||
Regulatory assets, current | [8] | 38 | 44 |
Regulatory assets, noncurrent | [8] | 382 | 379 |
Environmental Remediation Costs [Member] | |||
Regulatory Assets | |||
Regulatory assets, noncurrent | [9] | 33 | 34 |
Deferred Storm Damage Costs [Member] | |||
Regulatory Assets | |||
Regulatory assets, noncurrent | [10] | 39 | 40 |
Deferred Transmission Operating Costs [Member] | |||
Regulatory Assets | |||
Regulatory assets, noncurrent | [11] | 73 | 74 |
Derivative [Member] | |||
Regulatory Assets | |||
Regulatory assets, noncurrent | [12] | $ 99 | $ 103 |
[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 . 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. Represents the changes in fair value and payments made or received upon settlement of certain interest rate derivatives designated as cash flow hedges. The amounts recorded are expected to be amortized to interest expense over the lives of the underlying debt through 2065 . 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 depreciation 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 through 2033 . In addition, amounts include unrecovered costs of existing meters and equipment retired from service prior to being fully depreciated as part of the Advanced Metering Infrastructure project, which are being recovered through rates through 2028 . This amount also includes certain inventory and preliminary survey and investigation charges being amortized over five years related to the transition or conversion from coal to gas fired generation at certain facilities. 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. Various other regulatory assets are expected to be recovered through rates over varying periods through 2078 . Represents amounts under- or over-collected from customers pursuant to the cost of fuel and purchased gas components approved by the South Carolina Commission. Represents uncollected costs, including 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. 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 24 years. See Note 10 for additional information. Represents storm restoration costs for which DESC expects to receive future recovery through customer rates over approximately 10 years pursuant to the settlement agreement approved in DESC’s retail electric base rate case. Unamortized amounts are included in rate base and are earning a current return. Includes deferred depreciation and property taxes associated with certain transmission assets for which DESC expects recovery from customers through future rates over approximately 42 years pursuant to the settlement agreement approved in DESC’s retail electric base rate case. Unamortized amounts are included in rate base and earning a current return. See Note 12 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2023. Represents changes in the fair value of derivatives, excluding separately presented interest rate hedges, that following settlement are expected to be recovered from or refunded to customers. |
Rate and Other Regulatory Mat_5
Rate and Other Regulatory Matters (Schedule of Regulatory Liabilities) (Detail) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023 | |
Regulatory Liabilities | |||
Regulatory liability, current | $ 233 | $ 205 | |
Regulatory liability, noncurrent | 2,598 | 2,579 | |
Total regulatory liabilities | 2,831 | 2,784 | |
Monetization Of Guaranty Settlement [Member] | |||
Regulatory Liabilities | |||
Regulatory liability, current | [1] | 67 | 67 |
Regulatory liability, noncurrent | [1] | 619 | 635 |
Income Taxes Refundable Through Future Rates [Member] | |||
Regulatory Liabilities | |||
Regulatory liability, current | [2] | 37 | 37 |
Regulatory liability, noncurrent | [2] | 830 | 839 |
Reserve For Refunds To Electric Utility Customers [Member] | |||
Regulatory Liabilities | |||
Regulatory liability, current | [3] | 83 | 83 |
Regulatory liability, noncurrent | [3] | 212 | 237 |
Cost of Fuel and Purchased Gas Under-Collections [Member] | |||
Regulatory Liabilities | |||
Regulatory liability, current | [4] | 21 | |
Other Regulatory Liability [Member] | |||
Regulatory Liabilities | |||
Regulatory liability, current | 10 | 6 | |
Regulatory liability, noncurrent | 1 | 6 | |
Asset Removal Costs [Member] | |||
Regulatory Liabilities | |||
Regulatory liability, noncurrent | [5] | 640 | 633 |
Derivative [Member] | |||
Regulatory Liabilities | |||
Regulatory liability, current | [6] | 15 | 12 |
Regulatory liability, noncurrent | [6] | $ 296 | $ 229 |
[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 . 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 7 to the Consolidated Financial Statements in DESC’s Annual Report on Form 10-K for the year ended December 31, 2023 for additional information. 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. Represents amounts under- or over-collected from customers pursuant to the cost of fuel and purchased gas components approved by the South Carolina Commission. Represents estimated net collections through depreciation rates of amounts to be expended for the removal of assets in the future. Represents changes in the fair value of derivatives, excluding separately presented interest rate hedges, that following settlement are expected to be recovered from or refunded to customers. |
Revenue Recognition (Disaggrega
Revenue Recognition (Disaggregation of Revenue) (Detail) - USD ($) $ in Millions | 3 Months Ended | ||
Mar. 31, 2024 | Mar. 31, 2023 | ||
Total Operating Revenues | [1] | $ 775 | $ 759 |
Electric Operations | |||
Operating revenue from contracts with customers | 586 | 576 | |
Other revenues | 7 | 6 | |
Total Operating Revenues | 593 | 582 | |
Gas Distribution | |||
Operating revenue from contracts with customers | 182 | 177 | |
Other revenues | 0 | 0 | |
Total Operating Revenues | 182 | 177 | |
Residential | Electric Operations | |||
Operating revenue from contracts with customers | 283 | 262 | |
Residential | Gas Distribution | |||
Operating revenue from contracts with customers | 117 | 109 | |
Commercial | Electric Operations | |||
Operating revenue from contracts with customers | 188 | 187 | |
Commercial | Gas Distribution | |||
Operating revenue from contracts with customers | 41 | 42 | |
Industrial | Electric Operations | |||
Operating revenue from contracts with customers | 87 | 91 | |
Industrial | Gas Distribution | |||
Operating revenue from contracts with customers | 18 | 22 | |
Other | Electric Operations | |||
Operating revenue from contracts with customers | 28 | 36 | |
Other | Gas Distribution | |||
Operating revenue from contracts with customers | $ 6 | $ 4 | |
[1] See Note 12 for amounts attributable to affiliates. |
Revenue Recognition (Narrative)
Revenue Recognition (Narrative) (Detail) - USD ($) $ in Millions | 3 Months Ended | ||
Mar. 31, 2024 | Mar. 31, 2023 | Dec. 31, 2023 | |
Revenue from Contract with Customer [Abstract] | |||
Contract liability balances | $ 6 | $ 7 | |
Revenue recognized from contract liability balances | $ 3 | $ 7 |
Revenue Recognition (Balance an
Revenue Recognition (Balance and Activity Related to Contract Costs Deferred as Regulatory Assets) (Detail) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended |
Mar. 31, 2024 | Dec. 31, 2023 | |
Revenues [Abstract] | ||
Beginning balance | $ 11 | $ 9 |
Additional costs | 0 | 3 |
Amortization | 0 | (1) |
Ending balance | $ 11 | $ 11 |
Equity (Narrative) (Detail)
Equity (Narrative) (Detail) - $ / shares | Mar. 31, 2024 | Dec. 31, 2023 |
Class Of Stock [Line Items] | ||
Common stock, par value | ||
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 | ||
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 |
Long-Term and Short-Term Debt_2
Long-Term and Short-Term Debt (Narrative) (Detail) - USD ($) | 3 Months Ended | 12 Months Ended | |||
Mar. 31, 2024 | Mar. 31, 2023 | Dec. 31, 2023 | Sep. 30, 2023 | ||
Debt Instrument [Line Items] | |||||
Commercial paper borrowing limit | $ 2,200,000,000 | ||||
Affiliated and related party payables and other | $ 133,000,000 | $ 166,000,000 | |||
Interest charges | [1] | 67,000,000 | $ 59,000,000 | ||
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 | ||||
Genco | Maximum [Member] | |||||
Debt Instrument [Line Items] | |||||
Short term commercial paper maturity period | 1 year | ||||
Dominion Energy | |||||
Debt Instrument [Line Items] | |||||
Affiliated and related party payables and other | 672,000,000 | $ 442,000,000 | |||
Interest charges | 10,000,000 | $ 13,000,000 | |||
Inter company credit facility maximum capacity | 900,000,000 | ||||
Dominion Energy | Genco | |||||
Debt Instrument [Line Items] | |||||
Inter company credit facility maximum capacity | 200,000,000 | ||||
Dominion Energy | Fuel company | |||||
Debt Instrument [Line Items] | |||||
Inter company credit facility maximum capacity | 400,000,000 | ||||
Joint Revolving Credit Facility | |||||
Debt Instrument [Line Items] | |||||
Maximum Facility Sub-Limit | [2] | 1,000,000,000 | |||
Joint Revolving Credit Facility | Commercial Paper | |||||
Debt Instrument [Line Items] | |||||
Debt instrument, face amount | 210,000,000 | ||||
Joint Revolving Credit Facility | Dominion Energy | |||||
Debt Instrument [Line Items] | |||||
Maximum Facility Sub-Limit | $ 6,000,000,000 | ||||
Industrial Revenue Bonds | |||||
Debt Instrument [Line Items] | |||||
Debt instrument, face amount | 68,000,000 | $ 68,000,000 | |||
Intercompany Credit Facility | |||||
Debt Instrument [Line Items] | |||||
Line of credit, outstanding | 371,000,000 | ||||
Intercompany Credit Facility | Genco | |||||
Debt Instrument [Line Items] | |||||
Line of credit, outstanding | $ 23,000,000 | ||||
[1] See Note 12 for amounts attributable to affiliates. 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. A 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 March 31, 2024 , 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 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. |
Long-Term and Short-Term Debt_3
Long-Term and Short-Term Debt (Schedule of Line of Credit Facilities) (Detail) - Joint Revolving Credit Facility | Mar. 31, 2024 USD ($) | [1] |
Debt Instrument [Line Items] | ||
Maximum Facility Sub-Limit | $ 1,000,000,000 | |
Outstanding Commercial Paper | 210,000,000 | |
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. A 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 March 31, 2024 , 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 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. |
Long-Term and Short-Term Debt_4
Long-Term and Short-Term Debt (Schedule of Line of Credit Facilities) (Parenthetical) (Detail) | 3 Months Ended | |
Mar. 31, 2024 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] | ||
Maximum Facility Sub-Limit | $ 1,000,000,000 | [1] |
Line of Credit Facility | ||
Debt Instrument [Line Items] | ||
Maximum Facility Sub-Limit | 500,000,000 | |
Letter of Credit | ||
Debt Instrument [Line Items] | ||
Maximum Facility Sub-Limit | $ 1,000,000,000 | |
[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. A 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 March 31, 2024 , 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 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. |
Income Taxes - Schedule of Effe
Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Detail) | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Income Tax Disclosure [Abstract] | ||
U.S. statutory rate | 21% | 21% |
Increases (reductions) resulting from: | ||
State taxes, net of federal benefit | 3.90% | 4.10% |
Reversal of excess deferred income taxes | (5.30%) | (4.70%) |
Allowance for equity funds used during construction | (0.70%) | 0% |
Settlements of uncertain tax positions | 0% | (9.90%) |
Other, net | 0% | (0.10%) |
Effective tax rate | 18.90% | 10.40% |
Income Taxes (Narrative) (Detai
Income Taxes (Narrative) (Detail) $ in Millions | Mar. 31, 2023 USD ($) |
Income Taxes [Line Items] | |
Income tax benefit reasonably possible to occur | $ 11 |
Derivative Financial Instrume_3
Derivative Financial Instruments (Narrative) (Detail) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023 |
Derivative [Line Items] | ||
Additional collateral to its counterparties | $ 2 | $ 4 |
Collateral already posted | 0 | 0 |
Fair value of derivative instruments with credit-related contingent provisions that are in liability position and not fully collateralized with cash | $ 2 | $ 4 |
Derivative Financial Instrume_4
Derivative Financial Instruments (Offsetting Assets and Liabilities) (Detail) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023 | |
Assets | |||
Derivative [Line Items] | |||
Assets not offset in the consolidated balance sheet | [1] | $ 10 | $ 0 |
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 | 0 | 0 | |
Gross amounts not offset in the consolidated balance sheet, net amounts | 10 | 0 | |
Over The Counter [Member] | Assets | Interest Rate Contract [Member] | |||
Derivative [Line Items] | |||
Assets not offset in the consolidated balance sheet | [1] | 1 | 0 |
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 | 0 | 0 | |
Gross amounts not offset in the consolidated balance sheet, net amounts | 1 | 0 | |
Over The Counter [Member] | Assets | Commodity Contract [Member] | |||
Derivative [Line Items] | |||
Assets not offset in the consolidated balance sheet | [1] | 9 | 0 |
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 | 0 | 0 | |
Gross amounts not offset in the consolidated balance sheet, net amounts | 9 | 0 | |
Liability | |||
Derivative [Line Items] | |||
Gross liabilities presented in the consolidated balance sheet | [2] | 2 | 4 |
Gross amounts not offset in the consolidated balance sheet, financial instruments | 0 | 0 | |
Gross amounts not offset in the consolidated balance sheet, cash collateral paid | 0 | 0 | |
Gross amounts not offset in the consolidated balance sheet, net amounts | 2 | 4 | |
Liability | Over The Counter [Member] | Interest Rate Contract [Member] | |||
Derivative [Line Items] | |||
Gross liabilities presented in the consolidated balance sheet | [2] | 2 | 4 |
Gross amounts not offset in the consolidated balance sheet, financial instruments | 0 | 0 | |
Gross amounts not offset in the consolidated balance sheet, cash collateral paid | 0 | 0 | |
Gross amounts not offset in the consolidated balance sheet, net amounts | $ 2 | $ 4 | |
[1] Excludes derivative assets of $ 245 million and $ 176 million at March 31, 2024 and December 31, 2023, respectively, which are not subject to master netting or similar arrangements. DESC did no t have any derivative liabilities at March 31, 2024 and December 31, 2023, respectively, which were not subject to master netting or similar arrangements. |
Derivative Financial Instrume_5
Derivative Financial Instruments (Offsetting Assets and Liabilities) (Parenthetical) (Details) - USD ($) | Mar. 31, 2024 | Dec. 31, 2023 |
Derivative Instruments and Hedging Activities Disclosure [Abstract] | ||
Derivative assets not subject to master netting or similar arrangements | $ 245,000,000 | $ 176,000,000 |
Derivative liability not subject to master netting or similar arrangements | $ 0 | $ 0 |
Derivative Financial Instrume_6
Derivative Financial Instruments (Schedule of Volume of Derivative Activity) (Detail) MWh in Millions, Bcf in Millions | 3 Months Ended | |
Mar. 31, 2024 USD ($) Bcf MWh | ||
Interest Rate Swap Current [Member] | ||
Derivative [Line Items] | ||
Interest rate | $ | $ 0 | [1] |
Interest Rate Swap Current [Member] | Natural Gas (bcf) | ||
Derivative [Line Items] | ||
Basis | Bcf | 24 | [2] |
Interest Rate Swap Current [Member] | Electricity [Member] | ||
Derivative [Line Items] | ||
Fixed price | MWh | 2 | |
Interest Rate Swap Noncurrent [Member] | ||
Derivative [Line Items] | ||
Interest rate | $ | $ 71,000,000 | [1] |
Interest Rate Swap Noncurrent [Member] | Natural Gas (bcf) | ||
Derivative [Line Items] | ||
Basis | Bcf | 0 | [2] |
Interest Rate Swap Noncurrent [Member] | Electricity [Member] | ||
Derivative [Line Items] | ||
Fixed price | MWh | 23 | |
[1] Maturity is determined based on final settlement period. Includes options. |
Derivative Financial Instrume_7
Derivative Financial Instruments (Fair Value of Derivatives) (Detail) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023 | |
Derivative [Line Items] | |||
Derivative Asset, Current | [1] | $ 19 | $ 9 |
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration] | Other Assets, Current | Other Assets, Current | |
Derivative Asset, Noncurrent | [2] | $ 236 | $ 167 |
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Regulated Entity, Other Assets, Noncurrent | Regulated Entity, Other Assets, Noncurrent | |
Derivative Assets | $ 255 | $ 176 | |
Derivative Asset, Statement of Financial Position [Extensible Enumeration] | Assets | Assets | |
Derivative Liability, Noncurrent | [3] | $ 2 | $ 4 |
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Liabilities, Noncurrent | Liabilities, Noncurrent | |
Derivative Liability | $ 2 | $ 4 | |
Derivative Liability, Statement of Financial Position [Extensible Enumeration] | Liabilities and Equity | Liabilities and Equity | |
Commodity Contract [Member] | |||
Derivative [Line Items] | |||
Derivative Asset, Current | $ 19 | $ 9 | |
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration] | Other Assets, Current | Other Assets, Current | |
Derivative Asset, Noncurrent | $ 235 | $ 167 | |
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Regulated Entity, Other Assets, Noncurrent | Regulated Entity, Other Assets, Noncurrent | |
Interest Rate Contract [Member] | |||
Derivative [Line Items] | |||
Derivative Asset, Noncurrent | $ 1 | $ 0 | |
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Regulated Entity, Other Assets, Noncurrent | Regulated Entity, Other Assets, Noncurrent | |
Derivative Liability, Noncurrent | $ 2 | $ 4 | |
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Liabilities, Noncurrent | Liabilities, Noncurrent | |
Designated as Hedging Instrument [Member] | |||
Derivative [Line Items] | |||
Derivative Asset, Current | [1] | $ 0 | $ 0 |
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration] | Other Assets, Current | Other Assets, Current | |
Derivative Asset, Noncurrent | [2] | $ 0 | $ 0 |
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Regulated Entity, Other Assets, Noncurrent | Regulated Entity, Other Assets, Noncurrent | |
Derivative Assets | $ 0 | $ 0 | |
Derivative Asset, Statement of Financial Position [Extensible Enumeration] | Assets | Assets | |
Derivative Liability, Noncurrent | [3] | $ 0 | $ 0 |
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Liabilities, Noncurrent | Liabilities, Noncurrent | |
Derivative Liability | $ 0 | $ 0 | |
Derivative Liability, Statement of Financial Position [Extensible Enumeration] | Liabilities and Equity | Liabilities and Equity | |
Designated as Hedging Instrument [Member] | Commodity Contract [Member] | |||
Derivative [Line Items] | |||
Derivative Asset, Current | $ 0 | $ 0 | |
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration] | Other Assets, Current | Other Assets, Current | |
Derivative Asset, Noncurrent | $ 0 | $ 0 | |
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Regulated Entity, Other Assets, Noncurrent | Regulated Entity, Other Assets, Noncurrent | |
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | |||
Derivative [Line Items] | |||
Derivative Asset, Noncurrent | $ 0 | $ 0 | |
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Regulated Entity, Other Assets, Noncurrent | Regulated Entity, Other Assets, Noncurrent | |
Derivative Liability, Noncurrent | $ 0 | $ 0 | |
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Liabilities, Noncurrent | Liabilities, Noncurrent | |
Not Designated as Hedging Instrument [Member] | |||
Derivative [Line Items] | |||
Derivative Asset, Current | [1] | $ 19 | $ 9 |
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration] | Other Assets, Current | Other Assets, Current | |
Derivative Asset, Noncurrent | [2] | $ 236 | $ 167 |
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Regulated Entity, Other Assets, Noncurrent | Regulated Entity, Other Assets, Noncurrent | |
Derivative Assets | $ 255 | $ 176 | |
Derivative Asset, Statement of Financial Position [Extensible Enumeration] | Assets | Assets | |
Derivative Liability, Noncurrent | [3] | $ 2 | $ 4 |
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Liabilities, Noncurrent | Liabilities, Noncurrent | |
Derivative Liability | $ 2 | $ 4 | |
Derivative Liability, Statement of Financial Position [Extensible Enumeration] | Liabilities and Equity | Liabilities and Equity | |
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | |||
Derivative [Line Items] | |||
Derivative Asset, Current | $ 19 | $ 9 | |
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration] | Other Assets, Current | Other Assets, Current | |
Derivative Asset, Noncurrent | $ 235 | $ 167 | |
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Regulated Entity, Other Assets, Noncurrent | Regulated Entity, Other Assets, Noncurrent | |
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | |||
Derivative [Line Items] | |||
Derivative Asset, Noncurrent | $ 1 | $ 0 | |
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Regulated Entity, Other Assets, Noncurrent | Regulated Entity, Other Assets, Noncurrent | |
Derivative Liability, Noncurrent | $ 2 | $ 4 | |
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Liabilities, Noncurrent | Liabilities, Noncurrent | |
[1] Current derivative assets are presented in other current assets in DESC’s Consolidated Balance Sheets. Noncurrent derivative assets are presented in other deferred debits and other assets in DESC’s Consolidated Balance Sheets. Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in DESC’s Consolidated Balance Sheets. |
Derivative Financial Instrume_8
Derivative Financial Instruments (Derivatives in Cash Flow Hedging Relationships) (Detail) - Cash Flow Hedging [Member] - USD ($) $ in Millions | 3 Months Ended | ||
Mar. 31, 2024 | Mar. 31, 2023 | ||
Derivative [Line Items] | |||
Increase (Decrease) in Derivatives Subject to Regulatory Treatment | [1] | $ 0 | $ (1) |
Interest Rate Contract [Member] | |||
Derivative [Line Items] | |||
Increase (Decrease) in Derivatives Subject to Regulatory Treatment | [1] | $ 0 | $ (1) |
[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. |
Derivative Financial Instrume_9
Derivative Financial Instruments (Derivatives Not Designated as Hedging Instruments) (Detail) - Not Designated as Hedging Instruments [Member] - USD ($) $ in Millions | 3 Months Ended | ||
Mar. 31, 2024 | Mar. 31, 2023 | ||
Derivative [Line Items] | |||
Amount of Gain (Loss) Recognized in Income on Derivatives | [1] | $ (3) | $ 1 |
Commodity Contract [Member] | |||
Derivative [Line Items] | |||
Amount of Gain (Loss) Recognized in Income on Derivatives | [1] | $ (2) | $ 1 |
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Utilities Operating Expense, Purchased Power | Utilities Operating Expense, Purchased Power | |
Interest Rate Contract [Member] | |||
Derivative [Line Items] | |||
Amount of Gain (Loss) Recognized in Income on Derivatives | [1] | $ (1) | $ 0 |
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Interest Expense | Interest Expense | |
[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. |
Fair Value Measurements, Incl_3
Fair Value Measurements, Including Derivatives (Schedule of Quantitative Information About Level 3 Fair Value Measurements) (Details) | Mar. 31, 2024 USD ($) | |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Total assets, fair value | $ 253,000,000 | |
Electricity [Member] | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Total assets, fair value | 246,000,000 | |
Natural gas [Member] | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Total assets, fair value | $ 7,000,000 | [1] |
Fair value inputs price volatility | 34% | [2] |
Minimum [Member] | Electricity [Member] | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Total assets, fair value | $ 24,000,000 | |
Minimum [Member] | Natural gas [Member] | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Total assets, fair value | $ 1,000,000 | |
Fair value inputs price volatility | 10% | |
Maximum [Member] | Electricity [Member] | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Total assets, fair value | $ 102,000,000 | |
Maximum [Member] | Natural gas [Member] | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Total assets, fair value | $ 3,000,000 | |
Fair value inputs price volatility | 51% | |
Weighted Average [Member] | Electricity [Member] | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Total assets, fair value | $ 51,000,000 | [2] |
Weighted Average [Member] | Natural gas [Member] | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Total assets, fair value | $ 2,000,000 | [2] |
[1] Includes basis. Averages weighted by volume. |
Fair Value Measurements, Incl_4
Fair Value Measurements, Including Derivatives (Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - Fair value, recurring - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023 |
Assets | ||
Total assets | $ 255 | $ 176 |
Liabilities | ||
Total liabilities | 2 | 4 |
Commodity Contract [Member] | ||
Assets | ||
Total assets | 254 | 176 |
Interest Rate Contract [Member] | ||
Assets | ||
Total assets | 1 | 0 |
Liabilities | ||
Total liabilities | 2 | 4 |
Level 1 | ||
Assets | ||
Total assets | 0 | 0 |
Liabilities | ||
Total liabilities | 0 | 0 |
Level 1 | Commodity Contract [Member] | ||
Assets | ||
Total assets | 0 | 0 |
Level 1 | Interest Rate Contract [Member] | ||
Assets | ||
Total assets | 0 | 0 |
Liabilities | ||
Total liabilities | 0 | 0 |
Level 2 | ||
Assets | ||
Total assets | 2 | 0 |
Liabilities | ||
Total liabilities | 2 | 4 |
Level 2 | Commodity Contract [Member] | ||
Assets | ||
Total assets | 1 | 0 |
Level 2 | Interest Rate Contract [Member] | ||
Assets | ||
Total assets | 1 | 0 |
Liabilities | ||
Total liabilities | 2 | 4 |
Level 3 | ||
Assets | ||
Total assets | 253 | 176 |
Liabilities | ||
Total liabilities | 0 | 0 |
Level 3 | Commodity Contract [Member] | ||
Assets | ||
Total assets | 253 | 176 |
Level 3 | Interest Rate Contract [Member] | ||
Assets | ||
Total assets | 0 | 0 |
Liabilities | ||
Total liabilities | $ 0 | $ 0 |
Fair Value Measurements, Incl_5
Fair Value Measurements, Including Derivatives (Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis and Included in Level 3) (Details) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Regulatory Assets | ||
Beginning balance | $ 176 | $ 251 |
Included in earnings: | ||
Purchased power | (2) | 1 |
Settlements | 2 | (1) |
Purchases | 7 | |
Ending balance | 253 | 188 |
Other Regulatory Assets Liabilities | ||
Included in earnings: | ||
Included in regulatory assets/liabilities | $ 70 | $ (63) |
Fair Value Measurements, Incl_6
Fair Value Measurements, Including Derivatives (Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis) (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Derivative Instruments and Hedging Activities Disclosure [Abstract] | ||
Unrealized gains and losses | $ 0 | $ 0 |
Fair Value Measurements, Incl_7
Fair Value Measurements, Including Derivatives (Schedule of Carrying Values and Estimated Fair Values of Debt Instruments) (Detail) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2022 | |
Carrying Amount | |||
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items] | |||
Long-term debt | [1] | $ 4,219 | $ 4,219 |
Affiliated long-term debt | [2] | 230 | 230 |
Estimated Fair Value | |||
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items] | |||
Long-term debt | [1],[3] | 4,221 | 4,301 |
Affiliated long-term debt | [2],[3] | $ 230 | $ 230 |
[1] Carrying amount includes current portions, if any, presented in securities due within one year and amounts which represent the unamortized debt issuance costs and discount or premium. Carrying amount includes current portions presented in affiliated and related party payables. 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. |
Employee Benefit Plans (Compone
Employee Benefit Plans (Components of Net Periodic Benefit Cost (Credit) (Detail) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
Pension Plan | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Service cost | $ 2 | $ 2 |
Interest cost | 8 | 8 |
Expected return on assets | (9) | (8) |
Amortization of actuarial losses | 2 | 3 |
Net periodic benefit cost (credit) | 3 | 5 |
Other Postretirement Benefits Plan | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Service cost | 0 | 0 |
Interest cost | 2 | 2 |
Expected return on assets | 0 | 0 |
Amortization of actuarial losses | (1) | (1) |
Net periodic benefit cost (credit) | $ 1 | $ 1 |
Employee Benefit Plans (Narrati
Employee Benefit Plans (Narrative) (Detail) - USD ($) $ in Millions | 1 Months Ended | 3 Months Ended |
Apr. 30, 2024 | Mar. 31, 2024 | |
Defined Benefit Plan Disclosure [Line Items] | ||
Defined benefit plan, contributions by employer | $ 0 | |
Pension Plan | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Defined benefit plan, expected contributions in 2024 | $ 8 | |
Pension Plan | Subsequent Event | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Defined benefit plan, contributions by employer | $ 1 |
Commitments and Contingencies (
Commitments and Contingencies (Narrative) (Detail) shares in Millions | 1 Months Ended | 3 Months Ended | 12 Months Ended | ||||||||||||||||
Oct. 31, 2014 MGD Facility | Jul. 31, 2023 USD ($) | Jun. 30, 2023 USD ($) | Sep. 30, 2022 USD ($) | Jun. 30, 2022 USD ($) | May 31, 2022 shares | Aug. 31, 2021 shares | Jun. 30, 2021 USD ($) | Dec. 31, 2020 USD ($) | Oct. 31, 2020 | Nov. 30, 2019 gal | Jun. 30, 2018 USD ($) | Sep. 30, 2017 Petition | Apr. 30, 2017 Petition | Aug. 31, 2016 T | Mar. 31, 2024 USD ($) Indicator Facility Product | Mar. 31, 2023 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | |
Loss Contingencies [Line Items] | |||||||||||||||||||
Number of DESC facilities subject to final regulations | Facility | 5 | ||||||||||||||||||
Measurement of groundwater withdrawals | gal | 3,000,000 | ||||||||||||||||||
Number of manufacturing gas plant decommissioned sites that contain residues of byproduct chemicals | Product | 4 | ||||||||||||||||||
Estimated environmental remediation activities at manufacturing gas plant sites | $ 5,000,000 | ||||||||||||||||||
Environmental remediation costs recognized in regulatory assets | $ 34,000,000 | ||||||||||||||||||
Number of facilities inactive subject to final rule | Facility | 3 | ||||||||||||||||||
Proportionate ownership share in project | 100% | ||||||||||||||||||
Proposed assessment amount from SCDOR audit | $ 410,000,000 | ||||||||||||||||||
Litigation settlement expense awarded | $ 165,000,000 | ||||||||||||||||||
Real estate transfer to satisfy obligation under settlement | $ 51,000,000 | ||||||||||||||||||
Nuclear Insurance | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Maximum liability protection per nuclear incident amount | $ 16,300,000,000 | $ 16,200,000,000 | |||||||||||||||||
Maximum liability each nuclear plant is insured against | 500,000,000 | $ 450,000,000 | |||||||||||||||||
Surety Bonds | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Guarantee obligation | $ 24,000,000 | ||||||||||||||||||
SCDOR | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Fair value of certain additional utility property transferred | $ 3,000,000 | ||||||||||||||||||
Fair value of certain remaining utility property transferred | $ 11,000,000 | ||||||||||||||||||
Fair value of certain non-utility property transferred | $ 28,000,000 | ||||||||||||||||||
Fair value of certain utility property transferred | $ 10,000,000 | ||||||||||||||||||
Gain from transferred utility property | 9,000,000 | ||||||||||||||||||
Gain from transferred utility property, after tax | $ 7,000,000 | ||||||||||||||||||
Common Stock | Dominion Energy | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Litigation settlement through cash | $ 43,000,000 | ||||||||||||||||||
Shares issued on settlement | shares | 0.9 | 0.6 | |||||||||||||||||
Unfavorable Regulatory Action | CWA | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Electric generating stations with water withdrawals with heightened entrainment analysis under CWA | MGD | 2 | ||||||||||||||||||
Number of mandatory facility specific factors. | Indicator | 5 | ||||||||||||||||||
Number of optional facility specific factors | Indicator | 6 | ||||||||||||||||||
Personal Injury or Wrongful Death Cases | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Impairment of assets and other charges | $ 6,000,000 | ||||||||||||||||||
Maximum [Member] | SCDOR | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Cash payment | $ 1,000,000 | ||||||||||||||||||
Carbon Regulations [Member] | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Significant emission rate per year CO2 equivalent | T | 75,000 | ||||||||||||||||||
EPA | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Number of petition agreed for reconsideration | Petition | 2 | ||||||||||||||||||
EPA | Unfavorable Regulatory Action | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Electric generating stations with water withdrawals under CWA | MGD | 125 | ||||||||||||||||||
EPA | Unfavorable Regulatory Action | CWA | Final Rule to Revise Effluent Limitations Guidelines for Steam Electric Power Generating Category | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Number of separate petitions for reconsideration granted | Petition | 2 | ||||||||||||||||||
EPA | Minimum [Member] | Unfavorable Regulatory Action | CWA | Final Rule to Revise Effluent Limitations Guidelines for Steam Electric Power Generating Category | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Loss contingencies Individual circumstances period | 2021 | ||||||||||||||||||
EPA | Maximum [Member] | Unfavorable Regulatory Action | CWA | Final Rule to Revise Effluent Limitations Guidelines for Steam Electric Power Generating Category | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Loss contingencies Individual circumstances period | 2028 | ||||||||||||||||||
Environmental Protection Agency And State Regulatory Agencies | |||||||||||||||||||
Loss Contingencies [Line Items] | |||||||||||||||||||
Number of DESC hydroelectric facilities subject to regulations | Facility | 5 |
Operating Segments - Schedule o
Operating Segments - Schedule of Segment Information (Details) - USD ($) $ in Millions | 3 Months Ended | ||
Mar. 31, 2024 | Mar. 31, 2023 | ||
Segment Reporting Information [Line Items] | |||
External revenue | [1] | $ 775 | $ 759 |
Comprehensive income (loss) available (attributable) to common shareholder | 74 | 92 | |
Dominion Energy South Carolina, Inc. [Member] | |||
Segment Reporting Information [Line Items] | |||
External revenue | 775 | 759 | |
Comprehensive income (loss) available (attributable) to common shareholder | 75 | 86 | |
Corporate and Other | |||
Segment Reporting Information [Line Items] | |||
External revenue | 0 | 0 | |
Comprehensive income (loss) available (attributable) to common shareholder | $ (1) | $ 6 | |
[1] See Note 12 for amounts attributable to affiliates. |
Affiliated and Related Party _3
Affiliated and Related Party Transactions (Schedule of Affiliated Transactions - Income Statement) (Detail) - USD ($) $ in Millions | 3 Months Ended | ||
Mar. 31, 2024 | Mar. 31, 2023 | ||
Related Party Transaction [Line Items] | |||
Operating Revenues - Electric from sales to affiliate | $ 1 | $ 1 | |
Operating Expenses - Other taxes from affiliate | 3 | 3 | |
Solar Affiliates [Member] | |||
Related Party Transaction [Line Items] | |||
Purchases from affiliate | 1 | 2 | |
Related Party | DES | |||
Related Party Transaction [Line Items] | |||
Direct and allocated costs | [1] | $ 53 | $ 57 |
[1] Includes capitalized expenditures of $ 12 million and $ 16 million for the three months ended March 31, 2024 and 2023 , respectively. |
Affiliated and Related Party _4
Affiliated and Related Party Transactions (Schedule of Affiliated Transactions - Income Statement) (Parenthetical) (Detail) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2024 | Mar. 31, 2023 | |
DES | ||
Related Party Transaction [Line Items] | ||
Capitalized expenditures | $ 12 | $ 16 |
Affiliated and Related Party _5
Affiliated and Related Party Transactions (Schedule of Affiliated Transactions - Balance Sheet) (Detail) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023 | |
Related Party Transaction [Line Items] | |||
Affiliated and related party payables and other | $ 133 | $ 166 | |
Derivative assets with affiliates | [1] | 42 | 33 |
DES | Related Party | |||
Related Party Transaction [Line Items] | |||
Affiliated and related party payables and other | 41 | 18 | |
SCANA Corporation | Related Party | |||
Related Party Transaction [Line Items] | |||
Affiliated and related party payables and other | 7 | 7 | |
Public Service Company Of North Carolina Incorporated | Related Party | |||
Related Party Transaction [Line Items] | |||
Affiliated and related party payables and other | $ 12 | $ 13 | |
[1] Includes amounts recorded in other current assets of $ 2 million as of both March 31, 2024 and December 31, 2023 and amounts recorded in other deferred debits and other assets of $ 40 million and $ 31 million as of March 31, 2024 and December 31, 2023 , respectively. |
Affiliated and Related Party _6
Affiliated and Related Party Transactions (Schedule of Affiliated Transactions - Balance Sheet) (Parenthetical) (Detail) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023 | |
Related Party Transaction [Line Items] | |||
Derivative assets with affiliates | [1] | $ 42 | $ 33 |
Other Current Assets [Member] | |||
Related Party Transaction [Line Items] | |||
Derivative assets with affiliates | 2 | 2 | |
Other Deferred Debits and Other Assets [Member] | |||
Related Party Transaction [Line Items] | |||
Derivative assets with affiliates | $ 40 | $ 31 | |
[1] Includes amounts recorded in other current assets of $ 2 million as of both March 31, 2024 and December 31, 2023 and amounts recorded in other deferred debits and other assets of $ 40 million and $ 31 million as of March 31, 2024 and December 31, 2023 , respectively. |
Other Income, Net (Components o
Other Income, Net (Components of Other Income, Net) (Detail) - USD ($) $ in Millions | 3 Months Ended | ||
Mar. 31, 2024 | Mar. 31, 2023 | ||
Income Statement [Abstract] | |||
Other income | $ 2 | $ 2 | |
Gains on sales of assets | [1] | 1 | 10 |
Other expense | (5) | (2) | |
Allowance for equity funds used during construction | 3 | 0 | |
Other income, net | $ 1 | $ 10 | |
[1] Includes amounts recognized in 2023 in connection with the transfer of property to satisfy litigation. See Note 10 for additional information. |