South Carolina Transmission Power Lines

South Carolina's electric transmission infrastructure plays a critical role in supporting the state's energy needs, facilitating the distribution of electricity generated from a diverse combination of sources. This summary provides insights into the state’s transmission line network, major utilities, power generation mix, and energy development outlook.

Transmission Power Lines

South Carolina operates a robust system of over 5,000 miles of high-voltage transmission lines. These lines typically operate at voltages ranging from 115 kV to 500 kV, enabling efficient transport of electricity over long distances with minimal losses. The 230 kV and 500 kV lines form the backbone of the state’s electric grid, while lower voltage transmission lines (69 kV to 161 kV) serve regional and local distribution needs (EIA).

The state is also home to hundreds of electrical substations, which play a key role in stepping down voltage for distribution to homes and businesses. These substations help ensure the reliability and stability of the electric grid across urban and rural communities alike.

Major South Carolina Utilities

South Carolina’s electric utility landscape includes investor-owned utilities, state-owned entities, municipal providers, and electric cooperatives:

• Dominion Energy: Serving central and southern parts of the state, including Columbia and Charleston, Dominion Energy provides electricity to over 750,000 customers. In 2019, Dominion Energy acquired SCANA Corporation, the parent of South Carolina Electric & Gas (SCE&G), significantly expanding Dominion’s footprint in the state (Dominion).

• Duke Energy Carolinas & Duke Energy Progress: Operate in the upstate and northeastern regions of South Carolina, covering cities such as Greenville, Spartanburg, and Rock Hill.

• Santee Cooper (South Carolina Public Service Authority): The state-owned utility provides power directly to customers and supplies electric cooperatives and municipalities, reaching over 2 million South Carolinians (Santee Cooper).

• Electric Cooperatives of South Carolina: Represent 20 independent cooperatives that serve over 1.5 million people, particularly in rural areas (ECSC).

• Municipal Utilities: Several cities, including Rock Hill, Orangeburg, and Greenwood, operate their own municipal electric systems (Public Power).

  
  

  

  
  

South Carolina Power Generation Mix

South Carolina has a diverse energy generation portfolio that balances fossil fuels, nuclear, and renewables (EIA):

Nuclear Power: South Carolina is a nuclear-heavy state, with nuclear energy accounting for over 55% of the state’s electricity generation. Facilities like V.C. Summer and Oconee Nuclear Station are key contributors.

Natural Gas: Natural gas provides around 25% of the state's electricity. Its role continues to grow due to its efficiency and relatively low emissions.

Coal: Once dominant, coal-fired generation now contributes less than 10% of the state’s electricity. South Carolina is steadily retiring older coal plants in favor of cleaner energy sources.

Renewable Energy: Renewables currently account for approximately 7–10% of South Carolina’s power, with solar leading the way:

Solar Power: South Carolina has rapidly expanded solar capacity, now generating about 6% of its electricity from solar installations, including large-scale utility solar farms and rooftop systems.

Hydropower: Provides roughly 2% of the state’s electricity, primarily through small-scale hydro facilities.

Biomass: A minor but steady contributor, making up just under 1% of the generation mix.

Future Generation Outlook

South Carolina’s energy future is focused on diversifying generation sources, improving grid resilience, and reducing environmental impact (EIA):

1. Renewable Energy Growth: South Carolina continues to add solar capacity and explore offshore wind through partnerships and federal leasing opportunities (SEIA).

2. Nuclear Stability: With a strong base in nuclear energy, South Carolina is expected to continue investing in maintaining and upgrading its existing nuclear fleet to support long-term reliability (EIA).

3. Natural Gas Development: As coal plants retire, natural gas will continue to serve as a key bridge fuel, with investments in new combined-cycle gas facilities.

4. Coal Retirement: South Carolina plans to further reduce coal dependency, aligning with federal emission reduction targets and regional clean energy goals (EPA).

5. Grid Modernization: Ongoing investment in transmission infrastructure, smart grid technology, and energy storage will help improve reliability and enable integration of intermittent renewables.

   
   
   
   

Key Challenges and Initiatives

South Carolina’s main challenges include balancing grid reliability with the growing demand for cleaner energy and managing aging infrastructure. Statewide energy planning efforts and regional cooperation, particularly within the Southeast Energy Exchange Market (SEEM), aim to enhance electricity sharing, reduce costs, and improve renewable energy integration (SEEM).

With a growing population and an evolving energy landscape, South Carolina is poised to make strategic investments in clean energy, grid modernization, and resilience to meet the state’s future needs.

Sources: Dominion Energy, Duke Energy Carolinas, Santee Cooper, Electric Cooperatives of South Carolina, U.S. Energy Information Administration (EIA), EPA, Solar Energy Industries Association, South Carolina Office of Regulatory Staff, Southeast Energy Exchange Market.

Published by Line Reference. Visit linereference.com to view South Carolina transmission lines and substation power infrastructure.