Wind Turbine Payback in Perquimans County, NC
Wind turbine payback in Perquimans 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 Perquimans County, NC averages 4.97 m/s (11.1 mph). A 10 kW turbine there would make about 12,333 kWh a year, worth $1,843 at NC's 14.94¢/kWh. Against an installed cost of about $100,000, that is a payback of 54 years, and the turbine is built to last about 20.
What to do in Perquimans County
A home turbine is not worth buying for savings in Perquimans County unless your spot is far windier than the county average, 7.9 m/s at the hub against 4.97 m/s here. Per kW, solar panels would make about 1,270 kWh a year here against the turbine's 1,233, so get a solar quote first.
What would have to change
- Power would have to cost 41¢/kWh, 2.7 times what NC pays now.
- Or the average wind at the hub would have to be 7.9 m/s instead of 4.97. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of NC
Perquimans County is the 1,467th 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 Perquimans County
March is the strongest month here, at 5.61 m/s and about 1,430 kWh. August is the weakest, 4.00 m/s and 557 kWh, so the best month makes 2.6 times the worst. November to March brings in 50% of the year's output in Perquimans County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.40 m/s | 1,302 kWh | $195 |
| February | 5.51 m/s | 1,239 kWh | $185 |
| March | 5.61 m/s | 1,430 kWh | $214 |
| April | 5.65 m/s | 1,405 kWh | $210 |
| May | 4.99 m/s | 1,056 kWh | $158 |
| June | 4.40 m/s | 721 kWh | $108 |
| July | 4.24 m/s | 665 kWh | $99 |
| August | 4.00 m/s | 557 kWh | $83 |
| September | 4.66 m/s | 850 kWh | $127 |
| October | 4.85 m/s | 983 kWh | $147 |
| November | 5.11 m/s | 1,090 kWh | $163 |
| December | 5.22 m/s | 1,193 kWh | $178 |
What a taller tower would buy
Measured at 10 m the wind in Perquimans County averages 3.67 m/s; at 50 m it is 5.72 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 8,993 to 17,638 kWh a year, 96% 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 | 4.44 m/s | 8,993 kWh | 74 years |
| 30 m | 4.97 m/s | 12,318 kWh | 54 years |
| 40 m | 5.38 m/s | 15,164 kWh | 44 years |
| 50 m | 5.72 m/s | 17,638 kWh | 38 years |
Counties around Perquimans County
3 of the 6 closest counties are windier at turbine height; the windiest, Pasquotank County, averages 5.82 m/s.
- Pasquotank County, NC: 5.82 m/s, 18,374 kWh, payback 36 years (10 mi)
- Chowan County, NC: 4.96 m/s, 12,266 kWh, payback 55 years (12 mi)
- Camden County, NC: 5.82 m/s, 18,374 kWh, payback 36 years (17 mi)
- Gates County, NC: 5.06 m/s, 12,941 kWh, payback 52 years (25 mi)
- Washington County, NC: 4.96 m/s, 12,266 kWh, payback 55 years (25 mi)
- Tyrrell County, NC: 4.97 m/s, 12,333 kWh, payback 54 years (25 mi)
Sun versus wind in Perquimans County
Perquimans County gets 4.35 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,270 kWh a year; one kW of the turbine above makes 1,233. Kilowatt for kilowatt, panels make 1.0 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.