Wind Turbine Payback in Chatham County, NC
Wind turbine payback in Chatham 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 Chatham County, NC averages 3.54 m/s (7.9 mph). A 10 kW turbine there would make about 4,489 kWh a year, worth $671 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 Chatham County
A home turbine is not worth buying for savings in Chatham County unless your spot is far windier than the county average, 7.9 m/s at the hub against 3.54 m/s here. Per kW, solar panels would make about 1,296 kWh a year here against the turbine's 449, so get a solar quote first.
What would have to change
- Power would have to cost 111¢/kWh, 7.5 times what NC pays now.
- Or the average wind at the hub would have to be 7.9 m/s instead of 3.54. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of NC
Chatham County is the 2,473rd 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 Chatham County
March is the strongest month here, at 4.10 m/s and about 602 kWh. August is the weakest, 2.75 m/s and 164 kWh, so the best month makes 3.7 times the worst. November to March brings in 53% of the year's output in Chatham County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.91 m/s | 519 kWh | $78 |
| February | 4.06 m/s | 528 kWh | $79 |
| March | 4.10 m/s | 602 kWh | $90 |
| April | 4.12 m/s | 590 kWh | $88 |
| May | 3.53 m/s | 378 kWh | $56 |
| June | 3.06 m/s | 229 kWh | $34 |
| July | 2.84 m/s | 183 kWh | $27 |
| August | 2.75 m/s | 164 kWh | $25 |
| September | 3.25 m/s | 279 kWh | $42 |
| October | 3.50 m/s | 367 kWh | $55 |
| November | 3.67 m/s | 414 kWh | $62 |
| December | 3.72 m/s | 446 kWh | $67 |
What a taller tower would buy
Measured at 10 m the wind in Chatham County averages 2.26 m/s; at 50 m it is 4.36 m/s. That gives a shear exponent of 0.408, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,601 to 8,517 kWh a year, 227% 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 m/s | 2,601 kWh | over 100 years |
| 30 m | 3.54 m/s | 4,488 kWh | over 100 years |
| 40 m | 3.98 m/s | 6,480 kWh | over 100 years |
| 50 m | 4.36 m/s | 8,517 kWh | 79 years |
Counties around Chatham County
3 of the 6 closest counties are windier at turbine height; the windiest, Alamance County, averages 3.82 m/s.
- Lee County, NC: 3.54 m/s, 4,489 kWh, payback over 100 years (16 mi)
- Alamance County, NC: 3.82 m/s, 5,707 kWh, payback over 100 years (25 mi)
- Orange County, NC: 3.82 m/s, 5,707 kWh, payback over 100 years (26 mi)
- Moore County, NC: 3.54 m/s, 4,489 kWh, payback over 100 years (31 mi)
- Durham County, NC: 3.47 m/s, 4,211 kWh, payback over 100 years (31 mi)
- Randolph County, NC: 3.74 m/s, 5,342 kWh, payback over 100 years (31 mi)
Sun versus wind in Chatham County
Chatham 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 449. Kilowatt for kilowatt, panels make 2.9 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.