Rate and Other Regulatory Matters

6 Months Ended

Jun. 30, 2025

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, 2024.

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 2025, DESC filed with the South Carolina Commission a proposal to increase 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 2025. In addition, DESC proposed an increase to its variable environmental and avoided capacity cost component. The net effect is a proposed annual increase of $154 million. In March 2025, DESC and the South Carolina Office of Regulatory Staff filed a settlement agreement with the South Carolina Commission for approval to make certain adjustments to the February 2025 filing that would result in an inconsequential change to the proposed annual increase. In April 2025, the South Carolina Commission approved the settlement agreement, with rates effective with the first billing cycle of May 2025.

Electric - Transmission Project

In December 2024, DESC filed an application with the South Carolina Commission requesting approval of a CPCN to construct and operate the Ritter-Yemassee Transmission Line #2, comprised of a 17-mile 230 kV transmission line and associated facilities in Colleton and Hampton Counties, South Carolina with an estimated total project cost of $55 million. In April 2025, the South Carolina Commission approved the application.

Electric – Other

DESC has approval for a DSM rider through which it recovers expenditures related to its DSM programs. In January 2025, DESC filed an application with the South Carolina Commission seeking approval to recover $46 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 2025. In April 2025, the South Carolina Commission approved the request, effective with the first billing cycle of May 2025.

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 2025, DESC requested that the South Carolina Commission approve an adjustment to this rider to decrease annual revenue by $13 million. In April 2025, the South Carolina Commission approved the request.

Natural Gas Rates

In June 2025, DESC filed with the South Carolina Commission its monitoring report for the 12-month period ended March 31, 2025 with a total revenue requirement of $596 million. This revenue requirement represents a $17 million base rate increase under the terms of the Natural Gas Rate Stabilization Act effective with the first billing cycle of November 2025. This matter is pending.

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.



(millions)	June 30, 2025		December 31, 2024
Regulatory assets:
NND Project costs(1)	$	138	$	138
AROs(2)		4		8
Deferred employee benefit plan costs(3)		5		8
Other unrecovered plant(4)		18		18
DSM programs(5)		23		24
Cost of fuel and purchased gas under-collections(6)		83		35
Other		52		68
Regulatory assets - current		323		299
NND Project costs(1)		1,742		1,811
AROs(2)		709		695
Deferred employee benefit plan costs(3)		94		94
Interest rate hedges(7)		166		167
Other unrecovered plant(4)		98		89
DSM programs(5)		48		49
Environmental remediation costs(8)		42		42
Deferred storm damage costs(9)		76		76
Deferred transmission operating costs(10)		71		72
Derivatives(11)		93		95
Other(12)		198		152
Regulatory assets - noncurrent		3,337		3,342
Total regulatory assets	$	3,660	$	3,641
Regulatory liabilities:
Monetization of guaranty settlement(13)	$	67	$	67
Income taxes refundable through future rates(14)		19		24
Reserve for refunds to electric utility customers(15)		56		73
Derivatives(11)		36		27
Other		15		10
Regulatory liabilities - current		193		201
Monetization of guaranty settlement(13)		535		568
Income taxes refundable through future rates(14)		829		820
Asset removal costs(16)		599		598
Reserve for refunds to electric utility customers(15)		139		161
Derivatives(11)		234		328
Other		5		13
Regulatory liabilities - noncurrent		2,341		2,488
Total regulatory liabilities	$	2,534	$	2,689

(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. In addition, the balance reflects amounts related to the EPA’s May 2024 final rule concerning CCR as discussed in Note 10.

(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. Based on rates currently in effect, DESC expects to recover certain deferred benefit costs through utility rates over average service periods of participating employees, which is approximately 11 years. DESC expects to recover other deferred pension costs through utility rates over periods through 2044.

(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 2039. 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 through 2026 related to the transition or conversion from coal to gas fired generation at certain facilities. The majority of unamortized amounts are included in rate base and are earning a current return.

(5)

Primarily 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 settled interest rate derivatives designated as cash flow hedges 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. Pursuant to the settlement agreement approved in DESC’s retail electric base rate case in August 2024, for costs incurred prior to September 2024, DESC expects to receive future recovery through customer rates through 2034 and for costs incurred effective September 2024, DESC expects to receive future recovery through customer rates of approximately $2 million each year. 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 future recovery from customers through 2062. Unamortized amounts are included in rate base and earning a current return.

(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).

(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.