Wind Turbine Payback in Richland County, SC
Wind turbine payback in Richland 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 Richland County, SC averages 4.7 m/s (10.5 mph). A 10 kW turbine there would make about 10,571 kWh a year, worth $1,681 at SC's 15.9¢/kWh. Against an installed cost of about $100,000, that is a payback of 60 years, and the turbine is built to last about 20.
What to do in Richland County
A home turbine is not worth buying for savings in Richland County unless your spot is far windier than the county average, 7.6 m/s at the hub against 4.7 m/s here. Per kW, solar panels would make about 1,332 kWh a year here against the turbine's 1,057, so get a solar quote first.
What would have to change
- Power would have to cost 47¢/kWh, 3.0 times what SC pays now.
- Or the average wind at the hub would have to be 7.6 m/s instead of 4.7. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of SC
Richland County is the 1,610th 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 Richland County
March is the strongest month here, at 5.42 m/s and about 1,310 kWh. August is the weakest, 3.72 m/s and 448 kWh, so the best month makes 2.9 times the worst. November to March brings in 50% of the year's output in Richland County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.09 m/s | 1,118 kWh | $178 |
| February | 5.27 m/s | 1,103 kWh | $175 |
| March | 5.42 m/s | 1,310 kWh | $208 |
| April | 5.48 m/s | 1,304 kWh | $207 |
| May | 4.72 m/s | 907 kWh | $144 |
| June | 4.11 m/s | 586 kWh | $93 |
| July | 3.92 m/s | 527 kWh | $84 |
| August | 3.72 m/s | 448 kWh | $71 |
| September | 4.42 m/s | 729 kWh | $116 |
| October | 4.65 m/s | 870 kWh | $138 |
| November | 4.80 m/s | 920 kWh | $146 |
| December | 4.85 m/s | 979 kWh | $156 |
What a taller tower would buy
Measured at 10 m the wind in Richland County averages 3.5 m/s; at 50 m it is 5.39 m/s. That gives a shear exponent of 0.268, typical of ordinary open country. Going from 20 m to 50 m takes output from 7,713 to 15,247 kWh a year, 98% 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 | 4.22 m/s | 7,713 kWh | 82 years |
| 30 m | 4.7 m/s | 10,574 kWh | 60 years |
| 40 m | 5.08 m/s | 13,058 kWh | 48 years |
| 50 m | 5.39 m/s | 15,247 kWh | 41 years |
Counties around Richland County
1 of the 6 closest counties is windier at turbine height; the windiest, Lee County, averages 4.98 m/s.
- Lexington County, SC: 3.93 m/s, 6,231 kWh, payback over 100 years (23 mi)
- Calhoun County, SC: 4.42 m/s, 8,865 kWh, payback 71 years (25 mi)
- Kershaw County, SC: 3.44 m/s, 4,094 kWh, payback over 100 years (28 mi)
- Fairfield County, SC: 3.02 m/s, 2,661 kWh, payback over 100 years (29 mi)
- Sumter County, SC: 4.7 m/s, 10,571 kWh, payback 60 years (31 mi)
- Lee County, SC: 4.98 m/s, 12,400 kWh, payback 51 years (38 mi)
Sun versus wind in Richland County
Richland County gets 4.56 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,332 kWh a year; one kW of the turbine above makes 1,057. Kilowatt for kilowatt, panels make 1.3 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.