Solar in South Carolina: the 2026 numbers
A household here spending $200 a month on electricity needs roughly a 10.3 kW array, which generates about 14,873 kWh in its first year. Bought outright, it returns its cost in year 11 and is worth $11,640 over 25 years — after discounting, after upkeep, and with no federal credit.
Our answer for South Carolina: cash purchase
Of the four options, a cash purchase has the highest net present value at $11,640 , turning cash-positive in year 11 . Solar stops making sense in South Carolina above roughly $4.13/W installed — if a quote comes in above that, the answer flips.
What South Carolina gives you to work with
| Sunlight (specific yield) | 1444 kWh per installed kW per year — NREL PVWatts v8, Columbia |
| Average residential rate | $0.162/kWh — EIA, May 2026 |
| Export credit | 100% of retail — Net metering at retail under Act 62, alongside the largest state tax credit in the country. |
| Federal credit on a purchase | None — §25D expired after December 31, 2025 |
| State incentives | Worth about $3,333 in present value here — reviewed 2026-08-15 |
The four options, run side by side
A household spending $200 a month on electricity, with the array sized to cover its usage, at the default $3.00/W installed cost. This is the same case the calculator below opens on. Net present value discounts future dollars at 5%, so these are not the inflated “lifetime savings” totals a sales quote shows.
| Option | Net present value | Payback | Cost per kWh |
|---|---|---|---|
| Cash purchase You pay for it. No fee, no interest, no escalator. | $11,640 | Year 11 | $0.176 |
| Solar loan Includes the 20% dealer fee that a low-APR solar loan hides in the financed price. | -$418 | Year 1 | $0.236 |
| Lease You rent the system. The owner keeps the §48E credit. | $212 | Year 1 | $0.216 |
| PPA You buy the output per kWh, not the hardware. | $3,590 | Year 1 | $0.200 |
A cash purchase delivers electricity at $0.176/kWh while the utility charges $0.162. Generating your own is more expensive than buying it here, which is the core problem.
Best option: Cash purchase — $11,640 net present value over 25 years, paying back in year 11.
| Option | Owns it | 30% credit | Upfront | 25-yr NPV | Payback | Cost/kWh |
|---|---|---|---|---|---|---|
| Cash purchase | You | None | $30,900 | $11,640 | Year 11 | $0.176 |
| Solar loan | You | None | $0 | -$418 | Year 1 | $0.236 |
| Lease | Provider | Indirect (§48E) | $0 | $212 | Year 1 | $0.216 |
| PPA | Provider | Indirect (§48E) | $0 | $3,590 | Year 1 | $0.200 |
What this calculation assumes, and where it can be wrong
Federal credit. The 30% federal residential credit (IRC §25D) expired for systems placed in service after December 31, 2025. A 2026 cash or loan purchase receives no federal credit. Leases and PPAs remain eligible indirectly: the third-party owner claims the commercial credit (IRC §48E) and reflects part of it in the price offered, provided the system is placed in service by December 31, 2027.
Estimated §48E value in a lease or PPA quote: about $4,635 for this system, assuming the provider passes through half the credit. That share is our estimate, not a published figure.
Export credit. Net metering at retail under Act 62, alongside the largest state tax credit in the country.
State incentives. South Carolina's solar credit is 25% of system cost — the highest rate of any state we model — but it is claimed at no more than $3,500 a year, carried forward for up to ten years, to a lifetime maximum of $35,000. We model the $3,500 first-year amount rather than the full 25%, deliberately: the rest is real but arrives in later years and is worth less once discounted, and it depends on having South Carolina tax liability each year to absorb it. A household with steady state tax liability will do better than shown here.
- Cash purchase: No federal tax credit is applied: IRC §25D expired for systems placed in service after 2025-12-31.
- Solar loan: Financed amount includes a 20% dealer fee, which is why a $0-down loan quote costs more than the same system bought outright.
- Solar loan: No federal tax credit is applied: IRC §25D expired for systems placed in service after 2025-12-31.
- Lease: Pricing assumes the system owner claims the §48E credit and reflects part of it in your quote. The system must be placed in service by 2027-12-31 to qualify.
- PPA: Pricing assumes the system owner claims the §48E credit and reflects part of it in your quote. The system must be placed in service by 2027-12-31 to qualify.
Sunlight data: 1444 kWh per installed kW per year (verified — NREL PVWatts v8). Retail rate: $0.162/kWh.
Why South Carolina lands where it does
Across the 50 states we model, South Carolina ranks #15 on the value of a cash purchase, at $11,640 — behind Wisconsin at $11,691 and ahead ofColorado at $11,110 . The ordering is not the one people expect, and the reason is worth stating plainly: sunshine matters less than the price of the electricity you stop buying.
South Carolina gets 1444 kWh per installed kW per year and pays $0.162 per kWh. Neither figure is extreme, so the outcome turns on the export rule and the state programme rather than on the weather.
Full retail export, and what it hides
South Carolina credits exports at the full retail rate — Net metering at retail under Act 62, alongside the largest state tax credit in the country. That is the friendliest possible treatment, and it is why the numbers above are as strong as they are. It also means a battery buys you almost nothing financially here: if the grid already pays you retail for every exported kWh, storing that kWh to use later saves the same amount it would have earned. The value of storage in a full net-metering state is close to zero, and we say so on the battery calculator rather than selling you one.
The risk to watch is not the arithmetic but the rule. Full retail net metering is the concession utilities lobby hardest against, and California's move to NEM 3.0 cut export value to a quarter of retail. A 25-year model that assumes today's export rule survives all 25 years is making a policy bet, not just a financial one.
What the state actually pays you
South Carolina's solar credit is 25% of system cost — the highest rate of any state we model — but it is claimed at no more than $3,500 a year, carried forward for up to ten years, to a lifetime maximum of $35,000. We model the $3,500 first-year amount rather than the full 25%, deliberately: the rest is real but arrives in later years and is worth less once discounted, and it depends on having South Carolina tax liability each year to absorb it. A household with steady state tax liability will do better than shown here.
Run through the model, that is worth about $3,333 in present value on the reference system — 29% of the total value of a cash purchase here. With §25D gone, this is now the only public money on the table for a homeowner who buys.
The financing trap
A solar loan is worth -$418 here against $11,640 for the same system bought outright — a gap of $12,058. The interest rate is not what causes that. A 20% dealer fee is embedded in the financed price, which is how a "1.99% APR" offer ends up costing more than a bank loan at 8%. It is rarely on the quote. Ask for it by name.
Lease and PPA look different from a purchase for a structural reason: the third-party owner still claims the 30% §48E credit, which a homeowner buying outright can no longer get. How much of that credit reaches you in the price is a negotiation, and we assume half. The owner also carries the upkeep and the inverter replacement that a buyer pays for. That is why they still trail a cash purchase here, though by much less than they would have in 2025. Both are tied to systems placed in service by December 31, 2027 — see the 2027 deadline.
Before you accept a South Carolina quote
- Confirm it does not apply the expired 30% federal credit.
- Ask what export rate it assumed. South Carolina credits exports at 100% of retail; if the quote valued every kWh at $0.162, its savings figure is defensible on today’s rules.
- Check the price per watt. Above about $4.13/W the purchase stops paying for itself in South Carolina.
- Ask for the dealer fee on any financed offer, as a dollar amount.
- If it is a lease or PPA, ask for a placed-in-service commitment — §48E requires the system running by December 31, 2027.
More: the 2026 credit change, when solar is not worth it, our assumptions and sources.