Wind Turbine Payback in Mitchell County, NC
Wind turbine payback in Mitchell 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 Mitchell County, NC averages 3.37 m/s (7.5 mph). A 10 kW turbine there would make about 3,830 kWh a year, worth $572 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 Mitchell County
A home turbine is not worth buying for savings in Mitchell County unless your spot is far windier than the county average, 7.9 m/s at the hub against 3.37 m/s here. Per kW, solar panels would make about 1,232 kWh a year here against the turbine's 383, so get a solar quote first.
What would have to change
- Power would have to cost 131¢/kWh, 8.7 times what NC pays now.
- Or the average wind at the hub would have to be 7.9 m/s instead of 3.37. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of NC
Mitchell County is the 2,653rd 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 Mitchell County
January is the strongest month here, at 4.13 m/s and about 614 kWh. August is the weakest, 2.38 m/s and 95 kWh, so the best month makes 6.5 times the worst. November to March brings in 62% of the year's output in Mitchell County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.13 m/s | 614 kWh | $92 |
| February | 4.20 m/s | 584 kWh | $87 |
| March | 4.06 m/s | 586 kWh | $88 |
| April | 3.92 m/s | 507 kWh | $76 |
| May | 3.23 m/s | 282 kWh | $42 |
| June | 2.79 m/s | 166 kWh | $25 |
| July | 2.54 m/s | 122 kWh | $18 |
| August | 2.38 m/s | 95 kWh | $14 |
| September | 2.72 m/s | 151 kWh | $23 |
| October | 3.23 m/s | 284 kWh | $42 |
| November | 3.53 m/s | 366 kWh | $55 |
| December | 3.77 m/s | 466 kWh | $70 |
What a taller tower would buy
Measured at 10 m the wind in Mitchell County averages 2.11 m/s; at 50 m it is 4.19 m/s. That gives a shear exponent of 0.426, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,141 to 7,569 kWh a year, 254% 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 | 2.84 m/s | 2,141 kWh | over 100 years |
| 30 m | 3.37 m/s | 3,833 kWh | over 100 years |
| 40 m | 3.81 m/s | 5,661 kWh | over 100 years |
| 50 m | 4.19 m/s | 7,569 kWh | 88 years |
Counties around Mitchell County
2 of the 6 closest counties are windier at turbine height; the windiest, Carter County, averages 3.73 m/s.
- Yancey County, NC: 3.22 m/s, 3,299 kWh, payback over 100 years (12 mi)
- Avery County, NC: 3.37 m/s, 3,830 kWh, payback over 100 years (14 mi)
- Unicoi County, TN: 3.22 m/s, 3,299 kWh, payback over 100 years (15 mi)
- Carter County, TN: 3.73 m/s, 5,297 kWh, payback over 100 years (19 mi)
- McDowell County, NC: 3.24 m/s, 3,367 kWh, payback over 100 years (24 mi)
- Washington County, TN: 3.68 m/s, 5,077 kWh, payback over 100 years (27 mi)
Sun versus wind in Mitchell County
Mitchell County gets 4.22 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,232 kWh a year; one kW of the turbine above makes 383. 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.