South Carolina
Solar Permit Plans.
NEC 2020. Duke vs Dominion.
Net Metering Depends on Your Utility.
South Carolina runs NEC 2020 with state modifications and the 2021 IBC/IRC structural codes — but what makes this state genuinely complex for installers is the utility patchwork. Dominion Energy SC still offers 1:1 net metering (and the PSC just rejected a proposed rollback in January 2026), while Duke Energy ended 1:1 NEM in 2021 and now credits exported power at roughly 3–4 cents per kWh under Solar Choice Metering. The right sizing strategy and payback math are fundamentally different depending on which utility serves the project address.
One Electrical Code. Two Net Metering Realities. Four Separate Utilities.
Permit Design builds South Carolina solar permit plan sets for installers, EPCs, and roofing companies across all 46 counties. The statewide electrical code is NEC 2020 with SC modifications, effective January 1, 2020. Structural codes are the 2021 IBC and 2021 IRC with SC modifications, effective January 2023. South Carolina's energy code is still the 2009 IECC — one of the oldest in the US — though that affects mechanical and envelope design more than solar PV permitting directly.
What defines South Carolina for solar installers is the utility split. Dominion Energy SC (formerly SCE&G) still offers 1:1 net metering in the Midlands and Lowcountry. Duke Energy Carolinas and Duke Energy Progress ended 1:1 in 2021 and now credit surplus generation at roughly 2.6–4 cents per kWh under Solar Choice Metering. The South Carolina PSC rejected Dominion's proposed NEM rollback on January 30, 2026, keeping the 1:1 structure intact for new customers. The code is the same statewide — the export economics are not. Every plan set starts by confirming which utility serves the project address and which AHJ governs the permit — county building department or city inspection program.
Last updated: June 2026 · Reading time: ~8 minutes · NEC 2020 SC adoption, utility NEM programs, and January 2026 PSC ruling confirmed as of June 2026.
Which Utility Serves the Address Determines the Whole Economics.
South Carolina has no statewide net metering standard — each investor-owned utility negotiated its own tariff structure with the PSC under the Energy Freedom Act (Act 236/2014, updated Act 62/2019). What a customer earns for exported solar power differs by a factor of four or more depending on their utility.
Dominion Energy SC proposed a successor net metering tariff that would have imposed new fixed charges on solar customers and significantly reduced bill savings. The South Carolina PSC unanimously rejected the proposal on January 30, 2026, directing Dominion instead to move new distributed resource customers to a time-of-use rate schedule without the punitive charges Dominion sought. Dominion's existing 1:1 net metering with annual true-up remains available to new customers as of this writing. See psc.sc.gov for the full order. Duke Energy's separate Solar Choice Metering tariff is not affected by this ruling.
NEC 2020 + 2021 IBC + 2021 IRC — Plus One Outlier
South Carolina's code stack is mostly current — with one notable exception that surprises architects and energy consultants more than solar installers.
Four Utility Groups, Twenty Co-ops, One Critical Question: Who Serves This Address?
South Carolina's utility map looks deceptively simple from the outside — but the difference between a project in Dominion territory and one in Duke territory can reshape the entire proposal economics. Every SC plan set starts with a utility lookup and an AHJ confirmation — two separate checks that govern two separate parts of the permit package.
| Utility | Territory | Customers | Export Rate / Program | Notes |
|---|---|---|---|---|
| Dominion Energy SC | Midlands + Lowcountry — Columbia, Charleston, Aiken, Orangeburg, Beaufort | ~750,000 | 1:1 net metering — retail credit, annual true-up Nov at avoided cost | Formerly SCE&G; PSC rejected rollback proposal Jan 30, 2026 |
| Duke Energy Carolinas | Upstate SC — Greenville, Spartanburg, Anderson, Cherokee, York | ~700,000 | Solar Choice Metering — ~2.6–4¢/kWh exported | Filed to merge with Duke Energy Progress in the Carolinas |
| Duke Energy Progress | Pee Dee region — Florence, Darlington, Hartsville, Cheraw | ~200,000 | Solar Choice Metering — ~2.6–4¢/kWh exported | Also pending Carolinas merger with Duke Energy Carolinas |
| Santee Cooper | Berkeley, Georgetown, Horry counties — Myrtle Beach area | ~190,000 direct | ~4.2¢/kWh summer, ~3.8¢/kWh non-summer | State-owned utility; wholesales to 20 electric co-ops statewide |
| 20 Electric Cooperatives | Rural counties statewide — buy wholesale from Santee Cooper | 800,000+ | Monthly netting, excess ~3.8–5.9¢/kWh depending on co-op | Interconnection apps go to the specific co-op, not Santee Cooper |
South Carolina Solar Permit Plan Set Contents
Every South Carolina plan set is built to NEC 2020 with SC modifications, the 2021 IRC or IBC structural codes, and county-specific ASCE 7 wind and uplift values. The utility is confirmed by project address before the interconnection documentation is structured.
Also doing commercial rooftop, carport, or ground-mount in South Carolina?
South Carolina commercial solar structural packages reference the 2021 IBC with SC modifications — effective January 2023 — with NEC 2020 electrical and utility-specific interconnection documentation for Dominion Energy SC, Duke Energy Carolinas, Duke Energy Progress, Santee Cooper, or the relevant electric cooperative. The 2025 energy law raised the nonresidential net metering cap to 5 MW, opening up larger commercial projects to standard interconnection rather than bilateral utility agreements. Engineering support available for flat-roof ballasted and mechanically attached arrays, carport steel canopy structures, and ground-mount fixed-tilt or tracker installations. Custom scope and turnaround quoted per project.
How South Carolina Solar Permit Plan Sets Work
Submit Your South Carolina Project
Give us the county and street address. From that we confirm whether the project sits in Dominion Energy SC, Duke Energy Carolinas, Duke Energy Progress, Santee Cooper, or a specific co-op territory — and whether IRC 2021 or IBC 2021 structural provisions apply. The utility determination shapes both the export economics documentation and the interconnection format. AHJ confirmation is step one before any sheet is built.
We Build to NEC 2020 + the Confirmed Utility
NEC 2020 Article 690 electrical documentation with single-device rapid shutdown. IRC 2021 or IBC 2021 structural with ASCE 7-16 county-specific loads, accounting for coastal vs. inland wind exposure differences across SC's 46 counties. A South Carolina-licensed PE stamps the structural calculations.
Delivered in 24–48 Hours
The full South Carolina package ships in 24–48 hours from submission. Every sheet references the confirmed utility and the correct net metering program — Dominion's 1:1 framework or Duke's Solar Choice Metering — so the interconnection submission is clean from the start. Free revisions until your South Carolina AHJ approves.
Try Us on Your First South Carolina Project. Free.
New to Permit Design? Submit your first South Carolina residential project and we'll deliver the complete 7-sheet package at no charge — NEC 2020 electrical, IRC 2021 structural with ASCE 7-16 county loads, rapid shutdown per §690.12(C), and documentation formatted for the correct utility serving the project address.
Available for solar installers, EPCs, and roofing companies offering solar installation services. Not available for individual homeowners or end customers. One free residential plan set per company.
South Carolina Solar Permit Design — Frequently Asked Questions
South Carolina Solar by the Numbers
Top 3 Reasons South Carolina Solar Permits Get Rejected
Three permit rejection patterns account for most South Carolina delays across the state's mix of county building departments and municipal inspection offices. All three are avoidable with the right research before submission.
South Carolina Solar Permits —
Utility Confirmed. Code Verified.
NEC 2020 · AHJ-Confirmed · Duke vs Dominion Identified
Santee Cooper · 20 Co-ops · 46 Counties · 24–48 Hours