Wind Turbine Payback in Columbus County, NC
Wind turbine payback in Columbus 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 Columbus County, NC averages 4.42 m/s (9.9 mph). A 10 kW turbine there would make about 8,865 kWh a year, worth $1,324 at NC's 14.94¢/kWh. Against an installed cost of about $100,000, that is a payback of 76 years, and the turbine is built to last about 20.
What to do in Columbus County
A home turbine is not worth buying for savings in Columbus County unless your spot is far windier than the county average, 7.9 m/s at the hub against 4.42 m/s here. Per kW, solar panels would make about 1,320 kWh a year here against the turbine's 887, so get a solar quote first.
What would have to change
- Power would have to cost 56¢/kWh, 3.8 times what NC pays now.
- Or the average wind at the hub would have to be 7.9 m/s instead of 4.42. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of NC
Columbus County is the 1,799th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in NC is Dare County at 6.91 m/s, payback 25 years.
Month by month in Columbus County
April is the strongest month here, at 5.14 m/s and about 1,111 kWh. August is the weakest, 3.56 m/s and 389 kWh, so the best month makes 2.9 times the worst. November to March brings in 49% of the year's output in Columbus County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.68 m/s | 888 kWh | $133 |
| February | 4.90 m/s | 913 kWh | $136 |
| March | 5.01 m/s | 1,069 kWh | $160 |
| April | 5.14 m/s | 1,111 kWh | $166 |
| May | 4.49 m/s | 790 kWh | $118 |
| June | 3.92 m/s | 509 kWh | $76 |
| July | 3.81 m/s | 481 kWh | $72 |
| August | 3.56 m/s | 389 kWh | $58 |
| September | 4.19 m/s | 621 kWh | $93 |
| October | 4.32 m/s | 706 kWh | $105 |
| November | 4.49 m/s | 761 kWh | $114 |
| December | 4.53 m/s | 808 kWh | $121 |
What a taller tower would buy
Measured at 10 m the wind in Columbus County averages 3.15 m/s; at 50 m it is 5.17 m/s. That gives a shear exponent of 0.308, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 6,079 to 13,698 kWh a year, 125% 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 | 3.9 m/s | 6,079 kWh | over 100 years |
| 30 m | 4.42 m/s | 8,849 kWh | 76 years |
| 40 m | 4.83 m/s | 11,384 kWh | 59 years |
| 50 m | 5.17 m/s | 13,698 kWh | 49 years |
Counties around Columbus County
5 of the 6 closest counties are windier at turbine height; the windiest, Horry County, averages 5.29 m/s.
- Bladen County, NC: 4.42 m/s, 8,865 kWh, payback 76 years (24 mi)
- Brunswick County, NC: 4.73 m/s, 10,762 kWh, payback 62 years (28 mi)
- Horry County, SC: 5.29 m/s, 14,538 kWh, payback 43 years (31 mi)
- Robeson County, NC: 5 m/s, 12,535 kWh, payback 53 years (37 mi)
- Marion County, SC: 4.95 m/s, 12,199 kWh, payback 52 years (43 mi)
- Dillon County, SC: 5 m/s, 12,535 kWh, payback 50 years (43 mi)
Sun versus wind in Columbus County
Columbus County gets 4.52 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,320 kWh a year; one kW of the turbine above makes 887. Kilowatt for kilowatt, panels make 1.5 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.