Wind Turbine Payback in Union County, NC
Wind turbine payback in Union 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 Union County, NC averages 3.43 m/s (7.7 mph). A 10 kW turbine there would make about 4,056 kWh a year, worth $606 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 Union County
A home turbine is not worth buying for savings in Union County unless your spot is far windier than the county average, 7.9 m/s at the hub against 3.43 m/s here. Per kW, solar panels would make about 1,332 kWh a year here against the turbine's 406, so get a solar quote first.
What would have to change
- Power would have to cost 123¢/kWh, 8.3 times what NC pays now.
- Or the average wind at the hub would have to be 7.9 m/s instead of 3.43. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of NC
Union County is the 2,587th 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 Union County
March is the strongest month here, at 3.97 m/s and about 547 kWh. August is the weakest, 2.62 m/s and 137 kWh, so the best month makes 4.0 times the worst. November to March brings in 54% of the year's output in Union County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.81 m/s | 480 kWh | $72 |
| February | 3.95 m/s | 485 kWh | $72 |
| March | 3.97 m/s | 547 kWh | $82 |
| April | 4.01 m/s | 546 kWh | $82 |
| May | 3.43 m/s | 346 kWh | $52 |
| June | 2.95 m/s | 203 kWh | $30 |
| July | 2.73 m/s | 158 kWh | $24 |
| August | 2.62 m/s | 137 kWh | $20 |
| September | 3.13 m/s | 246 kWh | $37 |
| October | 3.39 m/s | 330 kWh | $49 |
| November | 3.57 m/s | 377 kWh | $56 |
| December | 3.59 m/s | 399 kWh | $60 |
What a taller tower would buy
Measured at 10 m the wind in Union County averages 2.2 m/s; at 50 m it is 4.21 m/s. That gives a shear exponent of 0.403, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,343 to 7,678 kWh a year, 228% 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 | 2.91 m/s | 2,343 kWh | over 100 years |
| 30 m | 3.43 m/s | 4,043 kWh | over 100 years |
| 40 m | 3.85 m/s | 5,837 kWh | over 100 years |
| 50 m | 4.21 m/s | 7,678 kWh | 87 years |
Counties around Union County
5 of the 6 closest counties are windier at turbine height; the windiest, Chesterfield County, averages 4.46 m/s.
- Lancaster County, SC: 3.44 m/s, 4,094 kWh, payback over 100 years (23 mi)
- Anson County, NC: 3.53 m/s, 4,449 kWh, payback over 100 years (24 mi)
- Mecklenburg County, NC: 3.43 m/s, 4,056 kWh, payback over 100 years (25 mi)
- Stanly County, NC: 3.74 m/s, 5,342 kWh, payback over 100 years (27 mi)
- Cabarrus County, NC: 4.41 m/s, 8,807 kWh, payback 76 years (27 mi)
- Chesterfield County, SC: 4.46 m/s, 9,100 kWh, payback 69 years (32 mi)
Sun versus wind in Union County
Union 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 406. Kilowatt for kilowatt, panels make 3.3 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.