Wind Turbine Payback in Greenville County, SC
Wind turbine payback in Greenville 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 Greenville County, SC averages 3.48 m/s (7.8 mph). A 10 kW turbine there would make about 4,250 kWh a year, worth $676 at SC's 15.9¢/kWh. Against an installed cost of about $100,000, that is a payback of over 100 years, and the turbine is built to last about 20.
What to do in Greenville County
A home turbine is not worth buying for savings in Greenville County unless your spot is far windier than the county average, 7.6 m/s at the hub against 3.48 m/s here. Per kW, solar panels would make about 1,340 kWh a year here against the turbine's 425, so get a solar quote first.
What would have to change
- Power would have to cost 118¢/kWh, 7.4 times what SC pays now.
- Or the average wind at the hub would have to be 7.6 m/s instead of 3.48. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of SC
Greenville County is the 2,536th 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 Greenville County
March is the strongest month here, at 4.09 m/s and about 597 kWh. August is the weakest, 2.62 m/s and 137 kWh, so the best month makes 4.4 times the worst. November to March brings in 55% of the year's output in Greenville County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.91 m/s | 523 kWh | $83 |
| February | 4.06 m/s | 526 kWh | $84 |
| March | 4.09 m/s | 597 kWh | $95 |
| April | 4.11 m/s | 585 kWh | $93 |
| May | 3.43 m/s | 345 kWh | $55 |
| June | 2.96 m/s | 203 kWh | $32 |
| July | 2.71 m/s | 154 kWh | $24 |
| August | 2.62 m/s | 137 kWh | $22 |
| September | 3.20 m/s | 265 kWh | $42 |
| October | 3.48 m/s | 361 kWh | $57 |
| November | 3.64 m/s | 403 kWh | $64 |
| December | 3.65 m/s | 419 kWh | $67 |
What a taller tower would buy
Measured at 10 m the wind in Greenville County averages 2.35 m/s; at 50 m it is 4.18 m/s. That gives a shear exponent of 0.358, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,634 to 7,515 kWh a year, 185% 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 | 3.01 m/s | 2,634 kWh | over 100 years |
| 30 m | 3.48 m/s | 4,255 kWh | over 100 years |
| 40 m | 3.86 m/s | 5,890 kWh | over 100 years |
| 50 m | 4.18 m/s | 7,515 kWh | 84 years |
Counties around Greenville County
1 of the 6 closest counties is windier at turbine height; the windiest, Spartanburg County, averages 3.7 m/s.
- Pickens County, SC: 3.48 m/s, 4,250 kWh, payback over 100 years (20 mi)
- Spartanburg County, SC: 3.7 m/s, 5,164 kWh, payback over 100 years (22 mi)
- Polk County, NC: 3.24 m/s, 3,367 kWh, payback over 100 years (29 mi)
- Anderson County, SC: 3.24 m/s, 3,367 kWh, payback over 100 years (30 mi)
- Henderson County, NC: 3.26 m/s, 3,436 kWh, payback over 100 years (31 mi)
- Transylvania County, NC: 3.05 m/s, 2,751 kWh, payback over 100 years (33 mi)
Sun versus wind in Greenville County
Greenville County gets 4.59 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,340 kWh a year; one kW of the turbine above makes 425. Kilowatt for kilowatt, panels make 3.2 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.