The real cost of going solar for a South Carolina home

If you’ve heard a neighbor brag about a “$0 power bill,” here’s the straight talk from the field: in South Carolina your electric utility, your rate plan, and a few one-time fees matter as much as the panels you bolt to the roof. A Dominion Energy customer in Columbia who goes solar lands on a specific time‑of‑use plan with higher prices between set hours, while a homeowner in Myrtle Beach on Santee Cooper gets a per‑kWh export credit and a published rooftop rebate. Those moving parts are what determine what you’ll actually pay and save.

Below is how the numbers work here, without the sales gloss. We’ll call out the real figures homeowners ask about every week: interconnection fees, TOU windows, per‑kWh credits, and state/federal incentives. If you only skim one section, make it the table — it compares what the three main South Carolina utilities and Dominion’s community solar program pay or charge on solar today.

“What will my bill look like under my utility?”

Dominion Energy South Carolina (DESC). New rooftop customers are placed on Rate 5, a time‑of‑use schedule. As of the tariff effective for bills rendered on and after July 2026, summer on‑peak energy (May–September) is billed at $0.29907/kWh, off‑peak at $0.15074/kWh, and super off‑peak at $0.09623/kWh. Winter (October–April) uses the same prices, with super off‑peak running 1:00–5:00 a.m. year‑round plus 12:00–3:00 p.m. in winter. The basic facilities charge on Rate 5 is $0.42740/day, and a $1/month Distributed Energy Resource charge also applies. Exports are credited within the Solar Choice framework using those TOU periods, so power pushed out at 3 p.m. winter super off‑peak doesn’t offset 6 p.m. summer on‑peak one‑for‑one.

Santee Cooper. Rooftop customers take service under the utility’s Distributed Generation Rider. Customer‑side solar that you consume offsets at retail; any extra energy sent back is credited at $0.0415/kWh. There’s a $10/month Distributed Generation customer charge, and residential interconnection applications carry a $100 fee. Santee Cooper also publishes a rooftop rebate of $950 per kW AC up to $5,700 per meter when funds are available, which is a direct cash‑flow reducer in year one.

Duke Energy Carolinas/Progress (South Carolina territories). New rooftop customers enroll in the Solar Choice tariff with a required residential time‑of‑use schedule. Monthly net excess is paid at Duke’s avoided‑cost export rate, which is updated through the Public Service Commission process. There is a minimum monthly bill at least equal to the basic customer charge under the schedule. For interconnection, Level 1 residential projects up to 20 kW submit a $100 application fee. If your neighbor in Greenville says “I still paid something,” that minimum bill and TOU structure is usually why.

One more utility detail that affects long‑term math: residential renewable systems of 20 kW AC or less are exempt from South Carolina property tax under state law, and the definition of “renewable energy resource property” includes modern inverter and battery equipment. If your project stays at or below 20 kW, the county assessor shouldn’t add panel value to your taxable base.

What will you actually pay out of pocket before credits and rebates?

There are four line items that show up on real contracts and utility paperwork in South Carolina, regardless of the equipment brand on the roof.

1) Interconnection and utility process. Santee Cooper charges a residential interconnection application fee of $100 and typically turns approvals within 10 business days once the DocuSign package is complete. Duke’s Level 1 residential application is also $100 for ≤20 kW. Dominion doesn’t collect a separate rooftop rebate or cash incentive; you’ll see Rate 5 enrollment, proof of property insurance per the South Carolina Interconnection Standard, and sometimes a W‑9 requirement if your annual credits are monetized.

2) Permitting and inspection. Rooftop solar here moves through your local building department for an electrical/structural permit and a final inspection before the utility installs or reprograms the bidirectional meter. Installers working in Santee Cooper territory schedule a utility acceptance test; rebates are typically mailed within about 6–8 weeks after that test passes.

3) Rate plan shift. Expect a plan change on solar activation if you’re with Dominion or Duke. Dominion’s Rate 5 on‑peak windows are 4:00–8:00 p.m. weekdays in summer and 6:00–9:00 a.m. weekdays in winter. Customers who run pool pumps, ovens, or EV charging during those windows will see a very different bill shape than they did on flat energy rates.

4) Optional community solar. If your roof is a no‑go, Dominion’s community solar program has published pricing: purchase at $2.25/watt with a $0.10/kWh bill credit, or subscribe with $0.20/kW monthly fee and a $0.01/kWh credit. Contracts run up to 20 years and carry a $50/kW termination or downsizing fee. The program has been fully subscribed at times, but the posted pricing structure is exactly what shows on bills when slots are available.

Two small but real operational costs we see homeowners gloss over: gutter cleaning and critter guards. In pine‑heavy neighborhoods around Lexington County and Berkeley County, leaves under panel edges attract squirrels. Budget a few hundred dollars for a one‑time screen if the installer doesn’t include it. It won’t change the utility math, but it can save a call‑out during summer thunderstorm season.

Which South Carolina incentives really move the needle?

Federal Investment Tax Credit. Residential solar, batteries charged by solar, and associated equipment qualify for a 30% federal income tax credit for systems placed in service through 2032, subject to your tax liability. This is a credit, not a deduction.

South Carolina Solar Energy Credit. South Carolina allows a 25% state income tax credit on the purchase and installation cost of a qualifying solar energy system at a property you own in the state. The credit taken in any one year is limited to the lesser of $3,500 per facility or 50% of your state income tax liability for that year. Unused amounts carry forward for up to 10 years. The Department of Revenue’s ruling also clarifies you generally must own the system to claim the credit; leased rooftop systems and off‑site “community solar” arrangements typically don’t qualify.

Utility rebates and bill credits. Santee Cooper’s rooftop rebate publishes at $950 per kW AC, capped at 6 kW AC or your home’s historic peak demand, whichever is lower. Excess energy exported to Santee Cooper’s grid credits at $0.0415/kWh. Dominion does not offer a rooftop cash rebate to homeowners; its published incentives are for community solar participation at $0.10/kWh bill credits under the purchase option and $0.01/kWh under the subscription option. Duke’s rooftop export credits are paid at its avoided‑cost rate per its Solar Choice rider, which is lower than retail and recalculated periodically in PSC filings.

Property tax and sales tax treatment. Under state law, renewable energy resource property with a nameplate capacity at or below 20 kW AC is exempt from local property tax, and that definition includes the inverter and, if installed, a battery. That keeps a typical home array from adding to your county tax bill in Greenville, Richland, Charleston, Horry, and beyond. Sales tax treatment depends on the specific equipment and invoice structure; your installer and tax professional should itemize the contract so your state credit is computed on eligible installed costs after any utility rebates that reduce basis.

On‑bill financing. In Santee Cooper territory, homeowners can apply for the Smart Energy Loan for Renewable Energy for up to $40,000, repaid on the power bill. If you’re not financing through a bank or credit union, that program is uniquely local and avoids a second monthly payment separate from your utility.

Rooftop, community solar, or wait and shift usage — which pencils out?

Here’s a side‑by‑side of the real programs and charges South Carolina homeowners actually encounter. These are not sales averages; they are the published utility rules and dollar figures that drive your bill.

A few practical notes we see on service calls: coastal homes with metal roofs in Horry and Georgetown counties often need a specific panel clamp series that adds a few hundred dollars but avoids roof penetrations; inland homes in Columbia on older shingle roofs might see a reroof allowance built into the quote. Neither changes your utility tariff math, but both change the contract bottom line before credits.

Quick takeaways to price a South Carolina solar job

• Check your utility first. If you’re on Dominion, budget around $0.30/kWh for summer on‑peak usage on Rate 5 and plan your heavy loads in super off‑peak windows.
• In Santee Cooper territory, add the $10/month DG charge and model your exports at $0.0415/kWh. Don’t forget the $950/kW AC rebate up to $5,700 if funds are available.
• For Duke customers, include the $100 interconnection fee and a minimum bill at least equal to the basic customer charge. Size the system with TOU in mind rather than chasing a $0 bill.
• Stack credits correctly. Federal 30% plus South Carolina’s 25% (limited to $3,500/facility per year and 50% of your SC liability, carryforward 10 years) can overlap, and utility rebates like Santee Cooper’s reduce your state‑credit basis.
• If your roof won’t work, Dominion’s community solar posts $2.25/watt purchase pricing with a $0.10/kWh bill credit. That’s transparent, bill‑ready math compared to many third‑party subscriptions.
• Residential systems at or below 20 kW AC are exempt from local property tax statewide; batteries and advanced inverters are covered in that definition.

Reader Q&A

Will I still get a bill after going solar in Columbia with Dominion Energy?

Yes. New rooftop customers move to Rate 5 time‑of‑use with a basic facilities charge of $0.42740/day and a $1 monthly DER charge. Your exports are credited within defined TOU windows, so even with strong production you’ll almost always see a minimum‑level bill unless your usage is shifted heavily to super off‑peak periods.

How does the Santee Cooper rebate actually pay out?

Qualifying rooftop systems receive a one‑time rebate of $950 per kW AC up to $5,700, calculated on AC output using inverter efficiency. After Santee Cooper’s acceptance test and meter work, rebates typically mail within about 6–8 weeks. Excess energy you send back later shows as a $0.0415/kWh bill credit.

I live in Greenville on Duke Energy. What fees hit before anything produces a kWh?

For a Level 1 residential interconnection up to 20 kW, Duke’s application fee is $100. You’ll be enrolled on a Solar Choice time‑of‑use schedule with a minimum monthly bill at least equal to the basic customer charge, and any net monthly exports are credited at Duke’s avoided‑cost rate as filed with the PSC.

Can I claim the South Carolina 25% credit and the federal 30% in the same year?

Yes. The state credit is 25% of eligible purchase and installation costs, limited to $3,500 per facility or 50% of your state income tax liability in a given year, with up to 10 years of carryforward. The federal 30% credit is separate. Your installer should show how any utility rebate (like Santee Cooper’s) affects the state credit calculation.

No two roofs or rate plans are identical, so the best filter is local. Start with your service address and utility, plug in the exact TOU windows, and ask your installer to show a bill model that uses those posted on‑peak and export credit rules. If the contract doesn’t include the interconnection fee that applies to your territory or the right rebate math, keep shopping.

Published: September 10, 2026 · Reviewed by the South Carolina editorial team