In South Carolina, a 9.2-kW system for an average home costs about $17,810 after incentives in 2026, saves about $2,034 in the first year and pays back in 7.9 years.
| Item | Amount |
|---|---|
| Solar, 9.24 kW × $2.57/W | $23,747 |
| Federal credit (0%) | $0 |
| State credit (spread over years) | −$5,937 |
| Net cost | $17,810 |
| Scenario | Net cost | Year-1 savings | Payback | 25-yr net |
|---|---|---|---|---|
| State averages (above) | $17,810 | $2,034 | 7.9 yr | $54,071 |
| Rates rise 5.6%/yr (2020–25 pace) | $17,810 | $2,034 | 7.3 yr | $83,280 |
| Rates stay flat | $17,810 | $2,034 | 8.8 yr | $31,753 |
| Survey price $3.6/W (LBNL) | $24,948 | $2,034 | 10.6 yr | $46,934 |
| Add 13.5-kWh battery | $34,604 | $2,034 | 14 yr | $37,277 |
| Exports cut to 50% of retail | $12,722 | $1,061 | 10.6 yr | $23,440 |
Verdict: at average South Carolina numbers, solar is a strong investment in 2026 — payback takes 7.9 years, leaving you $54,071 ahead after 25 years. The main reasons: 1:1 net metering, which credits every exported kWh at the full retail price; a state incentive worth about $5,937. Pay cash if you can: Berkeley Lab found loan-financed systems priced about $1.50/W above cash installs in 2025, which can add years to the payback.
Net metering and exports in South Carolina: Net metering requires a TOU plan; excess credited ~2-4¢/kWh (Solar Choice tariffs).
Battery: a 13.5-kWh battery at the South Carolina average of $1,244/kWh adds $16,794 and saves almost nothing extra under 1:1 net metering — buy it for backup, not payback; payback becomes 14 years.
EnergySage's South Carolina page lists a 15.7-year payback. Its method is not fully published; ours uses EIA's Jan–Aug 2026 price, 1:1 net metering, 3%/yr rate growth and 0.5%/yr panel aging, with no federal credit.
The full method, material data and tips are on the main solar payback calculator page.