Wind Turbine Payback in Alexander County, NC
Wind turbine payback in Alexander 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 Alexander County, NC averages 3.67 m/s (8.2 mph). A 10 kW turbine there would make about 5,034 kWh a year, worth $752 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 Alexander County
A home turbine is not worth buying for savings in Alexander County unless your spot is far windier than the county average, 7.9 m/s at the hub against 3.67 m/s here. Per kW, solar panels would make about 1,296 kWh a year here against the turbine's 503, so get a solar quote first.
What would have to change
- Power would have to cost 99¢/kWh, 6.6 times what NC pays now.
- Or the average wind at the hub would have to be 7.9 m/s instead of 3.67. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of NC
Alexander County is the 2,308th 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 Alexander County
March is the strongest month here, at 4.32 m/s and about 704 kWh. August is the weakest, 2.75 m/s and 164 kWh, so the best month makes 4.3 times the worst. November to March brings in 55% of the year's output in Alexander County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.15 m/s | 626 kWh | $94 |
| February | 4.30 m/s | 628 kWh | $94 |
| March | 4.32 m/s | 704 kWh | $105 |
| April | 4.33 m/s | 685 kWh | $102 |
| May | 3.64 m/s | 416 kWh | $62 |
| June | 3.15 m/s | 252 kWh | $38 |
| July | 2.89 m/s | 193 kWh | $29 |
| August | 2.75 m/s | 164 kWh | $25 |
| September | 3.21 m/s | 268 kWh | $40 |
| October | 3.59 m/s | 399 kWh | $60 |
| November | 3.79 m/s | 457 kWh | $68 |
| December | 3.86 m/s | 502 kWh | $75 |
What a taller tower would buy
Measured at 10 m the wind in Alexander County averages 2.45 m/s; at 50 m it is 4.42 m/s. That gives a shear exponent of 0.367, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 3,092 to 8,865 kWh a year, 187% 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 | 3.16 m/s | 3,092 kWh | over 100 years |
| 30 m | 3.66 m/s | 5,010 kWh | over 100 years |
| 40 m | 4.07 m/s | 6,947 kWh | 96 years |
| 50 m | 4.42 m/s | 8,865 kWh | 76 years |
Counties around Alexander County
3 of the 6 closest counties are windier at turbine height; the windiest, Iredell County, averages 4.41 m/s.
- Catawba County, NC: 4.22 m/s, 7,732 kWh, payback 87 years (18 mi)
- Iredell County, NC: 4.41 m/s, 8,807 kWh, payback 76 years (19 mi)
- Caldwell County, NC: 3.67 m/s, 5,034 kWh, payback over 100 years (19 mi)
- Wilkes County, NC: 3.67 m/s, 5,034 kWh, payback over 100 years (20 mi)
- Lincoln County, NC: 4.22 m/s, 7,732 kWh, payback 87 years (30 mi)
- Burke County, NC: 3.24 m/s, 3,367 kWh, payback over 100 years (32 mi)
Sun versus wind in Alexander County
Alexander 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 503. Kilowatt for kilowatt, panels make 2.6 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.