Solar panels in Charleston: what they cost and what they make
A typical Charleston home needs 21 solar panels. They would make about 12,958 kWh a year and cost $22k to $33k before incentives. At today's electricity prices they pay for themselves in about 9.8 yrs.
See panels on your own Charleston roof
Type your address. You get your roof from above, the panels that fit, a month-by-month forecast and a battery test. No phone number.
What solar costs in Charleston
At $3.00 a watt, the median price cash buyers pay nationally, a 8.8 kW system costs about $26,400. Quotes in Charleston will usually fall between $22,000 and $33,000. Complex roofs, main-panel upgrades and financing push prices up.
The 30% federal tax credit no longer applies to systems homeowners buy. SC credit (TC-38): 25% of cost, usable up to $3,500 per year (or 50% of tax liability) with 10-year carryforward. On this system that is worth about $6,615, and it is included below.
The number that decides whether solar pays in Charleston is what your utility pays for the power you send back. Under full payback is about 9.8 yrs. Under net billing it is about 16.2 yrs, because only the ~43% of solar a typical home uses as it is made saves the full retail price.
Cash purchase, prices rising 2.5% a year, panels losing 0.5% a year, $25/kW a year for upkeep. No federal credit for homeowner-owned systems.
Every way to pay for a 8.8 kW system in Charleston
Change any number →| Way to pay | Day one | Monthly payment | Monthly net, year 1 | Ahead after 25 years |
|---|---|---|---|---|
| Pay cash Full price on install day | $19,800 | $0 | +$154 | $41k |
| Credit-union loan 8% APR, 20 years, no dealer fee | $0 | $221 | −$67 | $14k |
| “1.99%” solar loan 1.99% APR, 25 years, 25% dealer fee | $0 | $140 | +$14 | $25k |
| Lease $145/mo, +2.9%/yr | $0 | $145 | +$27 | $3,400 |
| Power purchase (PPA) 13.5¢/kWh, +2.9%/yr | $0 | $146 | +$26 | $7,100 |
Under net metering, at 15.9¢/kWh rising 2.5% a year. The “1.99%” loan’s $6,600 dealer fee is included in its payments. Lease and PPA prices are typical offers, not quotes.
How much sunshine Charleston gets
kWh per kW, 25° southMay is the best month for solar in Charleston, and Dec the weakest: a Dec day makes 64% of a May day. A 6 kW system would make about 555 kWh in Dec and 872 kWh in May.
On June 21 the sun rises at 6:12 am and sets at 8:31 pm, 14 hours 19 minutes of daylight. On December 21 it is up from 7:18 am to 5:17 pm, just 9 hours 59 minutes.
Peak sun hours in Charleston, month by month
| Month | Flat ground | Panels at 30° | kWh per kW |
|---|---|---|---|
| Jan | 2.8 | 4.2 | 101 |
| Feb | 3.5 | 4.6 | 101 |
| Mar | 4.6 | 5.4 | 131 |
| Apr | 6.0 | 6.1 | 144 |
| May | 6.4 | 6.0 | 145 |
| Jun | 6.5 | 5.8 | 135 |
| Jul | 6.3 | 5.7 | 137 |
| Aug | 5.6 | 5.5 | 131 |
| Sep | 4.9 | 5.3 | 122 |
| Oct | 4.1 | 5.3 | 124 |
| Nov | 3.2 | 4.7 | 106 |
| Dec | 2.6 | 3.9 | 93 |
| Year | 4.7 | 5.2 | 1,469 |
A peak sun hour is one hour of sunlight at 1,000 W per m². Why sites disagree.
The best angle and direction for panels in Charleston
| Roof faces (6/12 pitch) | Output vs south | kWh per kW |
|---|---|---|
| South | 100% | 1,469 |
| Southeast | 96% | 1,410 |
| Southwest | 96% | 1,410 |
| East | 85% | 1,249 |
| West | 85% | 1,249 |
| North | 65% | 955 |
Face panels south and tilt them 30° for the most energy over a year. East and west roofs keep about 85% of that. A north-facing roof keeps 65%, which is rarely worth the money. Try other angles.
Where the sun goes over Charleston
The noon sun is lower in winter, which is why the best winter tilt (55°) is steeper than the best summer tilt (4°).
Charleston's homes
Charleston has 68,027 households. 55.6% own their home, and 33,890 of those owners live in single-family houses, the kind of home that usually gets rooftop solar.
The median home here was built in 1995. Many roofs that age are due for replacement. Replace the roof first, then add solar: taking panels off and putting them back later costs thousands.
73% of homes heat with electricity and 25% with gas. Electric heat raises winter use, so size solar to your own bills rather than the state average.
Source: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates.
If the power goes out in Charleston
Solar panels alone shut off in a blackout. Add a battery and they keep going. One Tesla Powerwall 3 (13.5 kWh) running a fridge, freezer, furnace fan, lights, Wi-Fi, TV and microwave (6.9 kWh a day):
Change the appliances, the battery and the weather in the battery calculator.
Questions people ask about solar in Charleston
How much do solar panels cost in Charleston?
A 8.8 kW system — enough for the average South Carolina home — costs about $22,000 to $33,000 before incentives, based on $2.50–$3.75 per watt. South Carolina's state tax credit takes off about $6,615. The 30% federal credit no longer applies to systems homeowners buy.
How many solar panels does a house in Charleston need?
About 21 panels of 420 watts for a home using 1,050 kWh a month, the South Carolina average. Each kilowatt of panels here makes about 1,469 kWh a year on a south-facing roof.
Is solar worth it in Charleston?
Over 25 years, solar power here costs about 8.3¢ per kWh, against 15.9¢ from the grid today. Payback is about 9.8 yrs if your utility credits exported power at the full retail rate, and 16.2 yrs if it pays about 30% of retail.
How many peak sun hours does Charleston get?
5.2 a day on panels tilted to 30°, and 4.7 on flat ground. The best month is Apr; the weakest is Dec.
What is the best angle for solar panels in Charleston?
30° for the most energy over a year, facing south. 55° is best in winter and 4° in summer. On a normal pitched roof, anything within 15° of 30° gives you about 95% of the maximum.
How long would a home battery last in a Charleston power outage?
A Tesla Powerwall 3 running a fridge, freezer, furnace fan, lights, Wi-Fi, TV and microwave (6.9 kWh a day) lasts about 43 hours with no sun. With 7 kW of solar to recharge it, it gets through a three-day outage even in overcast January.
Solar near Charleston
| City | Miles | kWh per kW | Sun hours |
|---|---|---|---|
| Mount Pleasant, SC | 6 | 1,470 | 5.2 |
| North Charleston, SC | 8 | 1,472 | 5.2 |
| Goose Creek, SC | 12 | 1,466 | 5.2 |
| Summerville, SC | 17 | 1,471 | 5.2 |
| Savannah, GA | 91 | 1,460 | 5.2 |
Cities with the same sunshine as Charleston
These far-away cities get almost exactly as much solar energy per panel.
- Dallas, TX 1,473 kWh per kW
- Waco, TX 1,473 kWh per kW
- Manhattan, KS 1,473 kWh per kW
Sources: NASA POWER 2001–2020 monthly climatology (grid cell 57 km from Charleston's Census point), our PV model (within 1.6% of NLR PVWatts® on average), U.S. EIA prices and use, U.S. Census 2025 population estimates and ACS 2020–2024. Estimates for an average home, not a site survey. How we calculate.