Wind Turbine Payback in Rutherford County, NC
Wind turbine payback in Rutherford 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 Rutherford County, NC averages 3.24 m/s (7.2 mph). A 10 kW turbine there would make about 3,367 kWh a year, worth $503 at NC's 14.94¢/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 Rutherford County
A home turbine is not worth buying for savings in Rutherford County unless your spot is far windier than the county average, 7.9 m/s at the hub against 3.24 m/s here. Per kW, solar panels would make about 1,296 kWh a year here against the turbine's 337, so get a solar quote first.
What would have to change
- Power would have to cost 149¢/kWh, 9.9 times what NC pays now.
- Or the average wind at the hub would have to be 7.9 m/s instead of 3.24. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of NC
Rutherford County is the 2,831st 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 Rutherford County
March is the strongest month here, at 3.83 m/s and about 489 kWh. August is the weakest, 2.43 m/s and 102 kWh, so the best month makes 4.8 times the worst. November to March brings in 56% of the year's output in Rutherford County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.69 m/s | 434 kWh | $65 |
| February | 3.82 m/s | 439 kWh | $66 |
| March | 3.83 m/s | 489 kWh | $73 |
| April | 3.82 m/s | 467 kWh | $70 |
| May | 3.19 m/s | 271 kWh | $40 |
| June | 2.75 m/s | 157 kWh | $23 |
| July | 2.51 m/s | 117 kWh | $17 |
| August | 2.43 m/s | 102 kWh | $15 |
| September | 2.88 m/s | 185 kWh | $28 |
| October | 3.18 m/s | 269 kWh | $40 |
| November | 3.35 m/s | 309 kWh | $46 |
| December | 3.42 m/s | 342 kWh | $51 |
What a taller tower would buy
Measured at 10 m the wind in Rutherford County averages 2.02 m/s; at 50 m it is 4.03 m/s. That gives a shear exponent of 0.429, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,846 to 6,729 kWh a year, 265% 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 | 2.72 m/s | 1,846 kWh | over 100 years |
| 30 m | 3.24 m/s | 3,357 kWh | over 100 years |
| 40 m | 3.66 m/s | 5,000 kWh | over 100 years |
| 50 m | 4.03 m/s | 6,729 kWh | 100 years |
Counties around Rutherford County
3 of the 6 closest counties are windier at turbine height; the windiest, Cleveland County, averages 4.22 m/s.
- Polk County, NC: 3.24 m/s, 3,367 kWh, payback over 100 years (16 mi)
- McDowell County, NC: 3.24 m/s, 3,367 kWh, payback over 100 years (21 mi)
- Cleveland County, NC: 4.22 m/s, 7,732 kWh, payback 87 years (21 mi)
- Burke County, NC: 3.24 m/s, 3,367 kWh, payback over 100 years (27 mi)
- Cherokee County, SC: 3.7 m/s, 5,164 kWh, payback over 100 years (30 mi)
- Henderson County, NC: 3.26 m/s, 3,436 kWh, payback over 100 years (32 mi)
Sun versus wind in Rutherford County
Rutherford County gets 4.44 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,296 kWh a year; one kW of the turbine above makes 337. Kilowatt for kilowatt, panels make 3.8 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.