US residential solar · 2026 data

Solar Panels in South Carolina

SAVE

$0+

Over 25 Years

$18,900 Cost after ITC
15.8 yrs Payback
9.0 kW Typical system

Most homeowners need:

  • 21–25 panels typical
  • 9.0 kW average system
  • $18,900 after tax credits
  • 15.8 year payback
✓ Updated monthly ✓ NREL data ✓ Reviewed by solar experts ✓ IRS tax credit included
· 9 min read ·By ·Reviewed by Green Energy Calculators Editorial Team

Without solar vs with solar

25-year cost comparison for a $300/month US electric bill.

Without solar

25-year utility cost

$50,300

Rates rise ~3% per year (EIA avg.)

With solar

Net system cost

$18,900

After 30% federal ITC

Your savings

Difference

+$31,400

Estimated lifetime advantage

500,000+
calculations completed
25,000+
users monthly

Trusted by US homeowners · Data sourced from

NREL EIA Energy.gov DSIRE IRS / SEIA
Author Mark Sullivan
Reviewed by Green Energy Calculators Editorial Team
Last updated
Sizing formula kW = Annual kWh ÷ (Peak Sun Hours × 365 × 0.82)

South Carolina homeowners who go solar in 2026 are looking at an average payback period of roughly 9 to 11 years — respectable, but highly dependent on which utility serves your address. Duke Energy Carolinas and Dominion Energy South Carolina both offer net metering programs, yet the credit rates, billing rules, and interconnection timelines differ enough that your utility choice can shift your lifetime solar savings by thousands of dollars. Understanding those differences before you sign a contract is the single most useful thing you can do.

The state’s average residential electricity rate sits at approximately 13.2 cents per kilowatt-hour (kWh) according to EIA data, slightly below the national average of around 16 cents. That lower rate softens solar economics a little compared to high-rate states like California, but the combination of 215 to 220 annual peak sun hours and a strong federal tax credit keeps the math attractive. A typical 8 kW system in the Columbia or Greenville metro area produces around 10,400 kWh per year — enough to cover most households’ annual consumption before any net metering credit kicks in.

North Carolina neighbors share Duke Energy Carolinas’ service territory, so many of the utility-level rules apply in both directions. Within South Carolina specifically, Dominion Energy (formerly SCE&G) serves the central and coastal regions including Columbia, while Duke Energy Carolinas covers the Upstate around Greenville and Spartanburg. A smaller number of residents fall under electric cooperatives, which have their own — often weaker — net metering policies.

How Net Metering Works in South Carolina

Net metering is the billing mechanism that makes rooftop solar financially viable for most homeowners. When your panels produce more electricity than your home uses at a given moment, the surplus flows back onto the grid and your meter runs in reverse. At the end of each billing period, you pay only for the net difference between what you consumed and what you exported.

South Carolina’s Public Service Commission established net metering rules that require investor-owned utilities — including both Duke Energy Carolinas and Dominion Energy SC — to offer the program to residential customers with systems up to 20 kW AC. The credits you receive for excess generation are applied to your next bill at the full retail rate, which is the same per-kWh price you would otherwise pay. This is called full retail net metering, and it is significantly more generous than avoided-cost or wholesale crediting, which some utilities in other states use.

The annual true-up matters. If your system produces more than you consume over a 12-month period, South Carolina utilities pay out any remaining credit at a lower avoided-cost rate — currently around 3 to 4 cents per kWh rather than the 13.2-cent retail rate. That asymmetry is why solar installers typically size systems to match roughly 95 to 100% of your annual usage rather than deliberately oversize them. Our solar net metering calculator lets you model exactly how much of your production will be self-consumed versus exported under different system sizes, so you can see how bill credits accumulate month by month.

Interconnection timelines in South Carolina average 30 to 60 days for residential systems under Duke and Dominion, though approvals can stretch longer during high-volume periods in spring. You cannot begin exporting to the grid until your utility issues permission to operate (PTO), even if your installer has already completed the physical installation and local inspection.

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Duke Energy Carolinas Net Metering: Rules for Upstate SC Homeowners

Duke Energy Carolinas serves roughly 570,000 customers in the Upstate South Carolina region. Its net metering tariff, filed with regulators in both Carolinas, credits residential solar production at the full retail rate on a monthly basis. Excess credits carry forward month to month within a 12-month period, with any remaining balance paid out at the avoided-cost rate each April.

One important detail for Duke customers: the company applies a fixed monthly customer charge — currently around $11 to $14 depending on your specific rate schedule — that you owe regardless of how much solar you produce. That charge is not offset by net metering credits. For a household producing enough solar to cover 100% of its energy usage, the annual out-of-pocket cost to Duke still runs $132 to $168 per year at minimum. For a full price breakdown by system size and region, see our guide to How Much Do Solar Panels Cost in 2026? Complete US.

Duke Energy Carolinas also maintains a formal interconnection queue. As of 2025, the residential queue has been manageable, but commercial-scale project additions can create processing backlogs that occasionally spill into residential timelines. Choosing an installer who files interconnection paperwork promptly after permit approval makes a real difference in how quickly you reach PTO and begin earning credits.

A 10 kW system in the Greenville area, where annual irradiance is strong, would generate approximately 13,000 kWh per year. At 13.2 cents per kWh retail credit, that offsets roughly $1,716 in annual electricity costs. Factor in a $14 monthly fixed charge and your net annual savings on a fully paid-off system sit around $1,548 before any production degradation. Duke’s territory in South Carolina borders Georgia to the south, where solar economics are similar but utility net metering rules differ.

Bar chart comparing retail net metering credit rates for Duke Energy Carolinas and Dominion Energy SC versus the avoided cost payout rate
South Carolina net metering credit rates differ sharply from avoided-cost payouts. Both Duke Energy Carolinas and Dominion Energy SC credit excess solar at the full retail rate of 13.2 cents/kWh, while annual surplus is paid out at just 3.5 cents/kWh — making proper system sizing critical. Source: EIA, SC PSC 2026.

Dominion Energy South Carolina Net Metering: Central and Coastal SC Rules

Dominion Energy South Carolina (formerly South Carolina Electric & Gas, or SCE&G) serves approximately 780,000 customers across the Midlands, Lowcountry, and coastal areas — including Columbia, Lexington, Summerville, and the Charleston metro. Its net metering program mirrors Duke’s in the most important way: residential customers receive full retail-rate credits for exported solar generation.

Dominion’s billing cycle and annual true-up date differ slightly from Duke’s, and the company has historically been slower to process interconnection applications during spring months when solar installation volume peaks. Plan for a 45 to 75 day interconnection window if you are targeting a summer activation, and confirm with your installer that paperwork was filed promptly after your local permit was issued.

Dominion Energy SC’s fixed monthly customer charge runs approximately $12.50 for standard residential accounts. Like Duke, this charge is not offset by net metering credits. Dominion customers should also check the utility’s current rebate offerings directly, as periodic incentives have appeared in past program years and details change annually.

For a Columbia homeowner with an 8 kW system producing 10,400 kWh annually, the retail offset at 13.2 cents equates to about $1,373 per year in electricity cost avoidance. Combined with the 30% federal Investment Tax Credit on a $24,000 system — a $7,200 credit — the result is a payback period of roughly 9.4 years on a cash purchase, assuming no financing costs and modest utility rate escalation of 2% per year. You can stress-test those assumptions with the solar payback calculator using your actual bill and roof size. Dominion’s service area includes coastal markets where Florida part-time residents sometimes maintain second homes, making the Lowcountry solar market unusually seasonal in its installation patterns.

South Carolina Solar Tax Credits and Incentives Worth Knowing

Net metering handles the ongoing economics of solar, but upfront incentives reduce what you invest in the first place. South Carolina offers a meaningful stack of programs that cut out-of-pocket costs before you ever flip the switch.

The federal Residential Clean Energy Credit — commonly called the solar ITC — remains at 30% through 2032, then drops to 26% in 2033 and 22% in 2034 before expiring for residential systems. On a $28,000 installation, the 30% credit reduces your federal tax liability by $8,400. This is a dollar-for-dollar tax reduction, not a deduction, so it carries full value only if your tax liability equals or exceeds the credit amount in that year. Unused portions can carry forward to future tax years. The IRS administers this credit through Form 5695, and our solar tax credit calculator walks through carryforward scenarios and AMT considerations in detail.

South Carolina also offers its own state-level incentive: a 25% state income tax credit on the cost of a solar system, capped at $3,500 per year and spread over five years if the total exceeds that cap. On a $28,000 system, the maximum state credit totals $7,000 — paid out at $1,400 per year over five years. Combined with the federal credit, the effective net cost of that same system drops to approximately $12,600, less than half the sticker price before a single kilowatt-hour of solar savings.

Property tax exemption provides additional value. South Carolina exempts the added assessed value of a solar installation from property taxation, so a system that raises your home’s appraised value by $25,000 does not increase your annual tax bill. A sales tax exemption on solar equipment also applies at purchase. SEIA data shows South Carolina ranked 21st nationally for solar capacity additions in 2024, reflecting steady growth with significant room to expand — particularly as battery storage adoption and time-of-use utility rates become more widespread across the state.

Cash Purchase, Solar Loan, or Lease: South Carolina Financing Compared

For most South Carolina homeowners, the choice of financing has nearly as much impact on long-term savings as panel brand or installer quality. Three main pathways dominate the market: outright cash purchase, solar loan, and solar lease or power purchase agreement (PPA).

A cash purchase delivers the highest lifetime return. You capture 100% of both the federal and state tax credits, own the system outright, and every dollar of electricity offset goes directly to your benefit. The drawback is straightforward — you need $20,000 to $35,000 available upfront. For homeowners with that liquidity, the all-in internal rate of return on South Carolina solar typically runs 8% to 11%, competitive with broad market investments and entirely uncorrelated to stock volatility.

A solar loan — typically 10 to 25 years at rates ranging from 4.99% to 8.99% as of early 2026 — lets you own the system and claim tax credits while spreading cost over time. The math works best when your monthly loan payment is close to your current electricity bill. On a $26,000 system with a $7,800 federal credit applied at tax time, a 20-year loan at 6.5% produces payments around $145 per month. If your current bill averages $165 per month, you are cash-flow positive from day one.

A solar lease or PPA means a third party owns the panels and sells you the electricity at a contracted rate. You pay nothing upfront and no maintenance costs, but you forfeit the federal and state tax credits entirely. PPAs in South Carolina are typically priced at 8 to 11 cents per kWh — below the current 13.2-cent retail rate — which does reduce your bill over time. The catch is a 20 to 25-year contract with annual escalators of 1% to 3% built in. If utility rates rise faster than the escalator, the deal stays favorable. If rates stagnate, the value erodes. Electric cooperatives in Virginia and nearby states have expanded community solar programs that could offer a middle path as those initiatives move into South Carolina markets. Before committing to any financing structure, the solar savings calculator can model your total 25-year return under each scenario side by side.

Frequently asked questions

Direct answers for US homeowners in South Carolina.

Yes. Both Duke Energy Carolinas and Dominion Energy South Carolina offer full retail net metering for residential systems up to 20 kW AC. Credits apply at approximately 13.2 cents per kWh and carry forward monthly. Any surplus at the annual true-up is paid at the avoided-cost rate of roughly 3 to 4 cents per kWh. Size your system to 95 to 100% of your annual usage to minimize low-value surplus at year-end.

Popular utility companies

Solar rules and net metering vary by utility — not just by state.

Methodology & data sources

Calculation method: System size uses NREL PVWatts derate factor (0.82). Costs based on SEIA 2026 installed cost ($2.75–$3.20/W). Payback uses net cost after 30% federal ITC (IRC Section 25D). Savings assume full-retail net metering unless noted.

Official sources: EIA state electricity rates · NREL PVWatts · Energy.gov ITC guide · DSIRE incentives · SEIA market data · IRS Publication 5695.

All figures are estimates for educational purposes — not tax, legal, or investment advice. Consult a licensed installer and CPA for your situation.

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