Dominion Energy South Carolina (DESC)

Overview

Dominion Energy South Carolina (DESC), organized in 1924 and headquartered in Cayce, South Carolina, is a public utility operating as a wholly owned subsidiary of SCANA, itself a subsidiary of Dominion Energy. DESC generates, transmits and distributes electricity to approximately 0.8 million customers across central, southern and southwestern South Carolina, and distributes natural gas to about 0.5 million residential, commercial and industrial customers. The company’s sales vary seasonally, with higher electricity demand in summer and winter and higher natural gas demand in winter.

Core business activities

• Generate, transmit and distribute electricity.
• Distribute natural gas.
• Purchase electricity under FERC-approved power purchase agreements (PPAs), including arrangements with external generators such as GENCO; related operating agreements support those transactions and their effects are eliminated in DESC’s consolidated financial statements.
• A related party, Fuel Company, acquires, owns and finances nuclear fuel, certain fossil fuels and environmental allowances.

Key assets and capacity

• Electric transmission: ~3,800 miles.
• Electric distribution: ~19,400 miles.
• Substations: 454.
• Gas distribution mains: ~20,000 miles.
• Gas transmission pipelines: ~400 miles.
• LNG facilities:
  • Charleston LNG: ~1.0 billion cubic feet (bcf) storage; regasify ~6% of storage per day; liquefaction <1% of storage per day.
  • Salley LNG: ~0.9 bcf storage; regasify ~10% of storage per day (no liquefaction).
• Total summer-rated utility generation capacity: 6,867 MW, by fuel:
  • Gas: 2,558 MW
  • Coal: 1,694 MW
  • Hydro: 784 MW
  • Nuclear: 644 MW
  • PPAs: 1,187 MW
• Example generating units contributing to capacity: Jasper CC (902 MW), Columbia Energy Center CC (522 MW), Wateree coal (684 MW), Cope coal (415 MW), Saluda hydro (190 MW), Fairfield hydro (576 MW), Jenkinsville nuclear (644 MW), and various combustion turbines and combined-cycle units.
• DESC holds an ownership interest in a nuclear generating unit that is subject to NRC regulation and decommissioning funding requirements.

Regulatory environment and rate setting

• Electric distribution and base rates are governed by the South Carolina Public Service Commission (SCPSC). Electric generation is subject to oversight by the SCPSC, FERC, NRC, EPA, DOE and other authorities. FERC primarily regulates electric transmission.
• Gas distribution rates are regulated by the SCPSC; gas safety and pipeline standards are enforced by PHMSA, DOT and ORS.
• Electric retail base rates are regulated on a cost-of-service/rate-of-return basis. Rates may be reviewed and adjusted if earned returns deviate from authorized levels.
• South Carolina Energy Stabilization Act (SCESA), enacted May 2025, provides a rate stabilization mechanism that allows eligible electric utilities to request annual base-rate adjustments when earned ROE deviates beyond a 50-basis-point band. Utilities electing rate stabilization must file a general rate case at least every five years. Facilities larger than 250 MW require a separate prudency review before costs can be included in rate stabilization.
• DESC uses a FERC-approved formula rate (approved 2011) to recover expected calendar-year transmission revenue requirements. In March 2025, FERC affirmed the SEEM framework for a voluntary electronic trading platform for bulk power trading.
• DESC maintains an exclusive franchise to serve retail electric customers within its South Carolina service territory, with potential future competition in transmission ownership under Order 1000 and natural gas competition based on price and convenience.

Rates, riders and recovery mechanisms

• Base rates recover operating costs and a return on invested capital; adjustments are subject to regulatory review and timing constraints.
• Riders and mechanisms include recovery for demand-side management (DSM) programs, pension costs and capital cost recovery for major projects. DESC files annual rider recoveries for fuel and DSM-related items.
• A capital cost rider supports the NND Project with a 20-year recovery period and includes returns to customers of specified amounts related to that project; the capital cost recovery declines over the period as the rider’s rate base is reduced.
• Recoverability of environmental and capital expenditures depends on regulatory approval and prudence determinations.

Operational and strategic considerations

• Operations are exposed to weather-driven demand variability, potential climate impacts, cyber threats, regulatory changes and capital market conditions.
• Environmental compliance risks include air, water and waste regulations, greenhouse gas policies and coal ash management.
• Construction and expansion projects require regulatory approvals and may face delays, scope changes or cost increases; recovery of those costs requires regulatory approval and prudence findings.
• Nuclear operations carry additional regulatory, decommissioning and insurance requirements, with potential cost impacts if safety or licensing standards change.

Related party arrangements

• GENCO operates a coal-fired plant that supplies electricity to DESC under a PPA; related transactions are structured under operating agreements and are eliminated in consolidated financial statements.
• Fuel Company provides financing and ownership for certain nuclear fuel, fossil fuels and environmental allowances used by DESC.

Key facts and figures (as of December 31, 2025)

• Employees: ~2,400 (about 740 subject to collective bargaining agreements)
• Electric customers: ~0.8 million
• Natural gas customers: ~0.5 million
• Electric transmission lines: ~3,800 miles
• Electric distribution lines: ~19,400 miles
• Substations: 454
• Natural gas transmission pipelines: ~400 miles
• Natural gas distribution mains: ~20,000 miles
• LNG capacity: Charleston ~1.0 bcf; Salley ~0.9 bcf
• Total utility generation capacity (summer): 6,867 MW
  • By fuel: Gas 2,558 MW; Coal 1,694 MW; Hydro 784 MW; Nuclear 644 MW; PPAs 1,187 MW

Security interest and financing

• DESC’s assets include a mortgage lien on substantially all electric utility property under its bond indenture.