Wind Turbine Payback in Colleton County, SC
Wind turbine payback in Colleton County
No. The turbine wears out before it pays for itself.
At 30 m, the height a home turbine tower usually reaches, the wind in Colleton County, SC averages 4.05 m/s (9.1 mph). A 10 kW turbine there would make about 6,831 kWh a year, worth $1,086 at SC's 15.9¢/kWh. Against an installed cost of about $100,000, that is a payback of 92 years, and the turbine is built to last about 20.
What to do in Colleton County
A home turbine is not worth buying for savings in Colleton County unless your spot is far windier than the county average, 7.6 m/s at the hub against 4.05 m/s here. Per kW, solar panels would make about 1,402 kWh a year here against the turbine's 683, so get a solar quote first.
What would have to change
- Power would have to cost 73¢/kWh, 4.6 times what SC pays now.
- Or the average wind at the hub would have to be 7.6 m/s instead of 4.05. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of SC
Colleton County is the 2,027th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in SC is Beaufort County at 5.71 m/s, payback 36 years.
Month by month in Colleton County
March is the strongest month here, at 4.60 m/s and about 844 kWh. August is the weakest, 3.31 m/s and 307 kWh, so the best month makes 2.7 times the worst. November to March brings in 50% of the year's output in Colleton County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.35 m/s | 721 kWh | $115 |
| February | 4.46 m/s | 696 kWh | $111 |
| March | 4.60 m/s | 844 kWh | $134 |
| April | 4.61 m/s | 821 kWh | $131 |
| May | 4.17 m/s | 633 kWh | $101 |
| June | 3.64 m/s | 403 kWh | $64 |
| July | 3.49 m/s | 363 kWh | $58 |
| August | 3.31 m/s | 307 kWh | $49 |
| September | 3.81 m/s | 464 kWh | $74 |
| October | 3.95 m/s | 538 kWh | $86 |
| November | 4.14 m/s | 598 kWh | $95 |
| December | 4.15 m/s | 626 kWh | $100 |
What a taller tower would buy
Measured at 10 m the wind in Colleton County averages 2.8 m/s; at 50 m it is 4.81 m/s. That gives a shear exponent of 0.336, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 4,470 to 11,276 kWh a year, 152% more, before counting the extra cost of the taller tower. Why tower height decides it explains the shear behind these numbers.
| Hub height | Average wind | Output | Payback |
|---|---|---|---|
| 20 m | 3.54 m/s | 4,470 kWh | over 100 years |
| 30 m | 4.05 m/s | 6,838 kWh | 92 years |
| 40 m | 4.46 m/s | 9,116 kWh | 69 years |
| 50 m | 4.81 m/s | 11,276 kWh | 56 years |
Counties around Colleton County
2 of the 6 closest counties are windier at turbine height; the windiest, Beaufort County, averages 5.71 m/s.
- Dorchester County, SC: 4.05 m/s, 6,831 kWh, payback 92 years (22 mi)
- Hampton County, SC: 4.02 m/s, 6,678 kWh, payback 94 years (29 mi)
- Bamberg County, SC: 4.02 m/s, 6,678 kWh, payback 94 years (34 mi)
- Beaufort County, SC: 5.71 m/s, 17,565 kWh, payback 36 years (34 mi)
- Jasper County, SC: 3.48 m/s, 4,250 kWh, payback over 100 years (36 mi)
- Orangeburg County, SC: 4.42 m/s, 8,865 kWh, payback 71 years (41 mi)
Sun versus wind in Colleton County
Colleton County gets 4.8 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,402 kWh a year; one kW of the turbine above makes 683. Kilowatt for kilowatt, panels make 2.1 times as much here as the turbine. Panel output assumes an 80% system performance ratio. Wind or solar runs the same comparison for every county.
How this is worked out
Wind is NASA's Power climate record, the 2001-2025 average at 10 m and 50 m for the county's centre, carried to 30 m with this county's own measured wind shear and spread into hours with a Rayleigh distribution. The turbine is a generic 10 kW, 7 m rotor machine with 10% losses. Cost is $10,000 per kW installed with no tax credit, because the federal one ended in 2025. One county-centre number cannot see your hilltop or your tree line, so treat it as the starting point for a site survey, not a substitute. The full method and its weak spots are in how the numbers are made.