Wind Turbine Payback in Greene County, NC
Wind turbine payback in Greene 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 Greene County, NC averages 4.94 m/s (11.1 mph). A 10 kW turbine there would make about 12,132 kWh a year, worth $1,813 at NC's 14.94¢/kWh. Against an installed cost of about $100,000, that is a payback of 55 years, and the turbine is built to last about 20.
What to do in Greene County
A home turbine is not worth buying for savings in Greene County unless your spot is far windier than the county average, 7.9 m/s at the hub against 4.94 m/s here. Per kW, solar panels would make about 1,305 kWh a year here against the turbine's 1,213, so get a solar quote first.
What would have to change
- Power would have to cost 41¢/kWh, 2.8 times what NC pays now.
- Or the average wind at the hub would have to be 7.9 m/s instead of 4.94. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of NC
Greene County is the 1,482nd 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 Greene County
March is the strongest month here, at 5.69 m/s and about 1,479 kWh. August is the weakest, 3.88 m/s and 510 kWh, so the best month makes 2.9 times the worst. November to March brings in 50% of the year's output in Greene County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.33 m/s | 1,260 kWh | $188 |
| February | 5.55 m/s | 1,258 kWh | $188 |
| March | 5.69 m/s | 1,479 kWh | $221 |
| April | 5.76 m/s | 1,473 kWh | $220 |
| May | 4.99 m/s | 1,061 kWh | $159 |
| June | 4.39 m/s | 712 kWh | $106 |
| July | 4.16 m/s | 629 kWh | $94 |
| August | 3.88 m/s | 510 kWh | $76 |
| September | 4.59 m/s | 810 kWh | $121 |
| October | 4.84 m/s | 973 kWh | $145 |
| November | 5.09 m/s | 1,080 kWh | $161 |
| December | 5.13 m/s | 1,142 kWh | $171 |
What a taller tower would buy
Measured at 10 m the wind in Greene County averages 3.65 m/s; at 50 m it is 5.69 m/s. That gives a shear exponent of 0.276, typical of ordinary open country. Going from 20 m to 50 m takes output from 8,857 to 17,419 kWh a year, 97% 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 | 4.42 m/s | 8,857 kWh | 76 years |
| 30 m | 4.94 m/s | 12,144 kWh | 55 years |
| 40 m | 5.35 m/s | 14,964 kWh | 45 years |
| 50 m | 5.69 m/s | 17,419 kWh | 38 years |
Counties around Greene County
2 of the 6 closest counties are windier at turbine height; the windiest, Wilson County, averages 5.2 m/s.
- Lenoir County, NC: 4.79 m/s, 11,147 kWh, payback 60 years (17 mi)
- Pitt County, NC: 4.94 m/s, 12,132 kWh, payback 55 years (19 mi)
- Wilson County, NC: 5.2 m/s, 13,907 kWh, payback 48 years (20 mi)
- Wayne County, NC: 5.2 m/s, 13,907 kWh, payback 48 years (20 mi)
- Edgecombe County, NC: 4.9 m/s, 11,866 kWh, payback 56 years (30 mi)
- Jones County, NC: 4.79 m/s, 11,147 kWh, payback 60 years (36 mi)
Sun versus wind in Greene County
Greene County gets 4.47 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,305 kWh a year; one kW of the turbine above makes 1,213. Kilowatt for kilowatt, panels make 1.1 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.