Wind Turbine Payback in Adair County, KY
Wind turbine payback in Adair 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 Adair County, KY averages 4 m/s (8.9 mph). A 10 kW turbine there would make about 6,577 kWh a year, worth $934 at KY's 14.2¢/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 Adair County
A home turbine is not worth buying for savings in Adair County unless your spot is far windier than the county average, 8.2 m/s at the hub against 4 m/s here. Per kW, solar panels would make about 1,212 kWh a year here against the turbine's 658, so get a solar quote first.
What would have to change
- Power would have to cost 76¢/kWh, 5.4 times what KY pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 4. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of KY
Adair County is the 2,058th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in KY is Fulton County at 5.54 m/s, payback 43 years.
Month by month in Adair County
March is the strongest month here, at 4.76 m/s and about 929 kWh. August is the weakest, 2.97 m/s and 214 kWh, so the best month makes 4.3 times the worst. November to March brings in 58% of the year's output in Adair County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.67 m/s | 882 kWh | $125 |
| February | 4.78 m/s | 851 kWh | $121 |
| March | 4.76 m/s | 929 kWh | $132 |
| April | 4.71 m/s | 876 kWh | $124 |
| May | 3.88 m/s | 508 kWh | $72 |
| June | 3.36 m/s | 311 kWh | $44 |
| July | 3.06 m/s | 236 kWh | $34 |
| August | 2.97 m/s | 214 kWh | $30 |
| September | 3.31 m/s | 298 kWh | $42 |
| October | 3.91 m/s | 521 kWh | $74 |
| November | 4.23 m/s | 639 kWh | $91 |
| December | 4.43 m/s | 759 kWh | $108 |
What a taller tower would buy
Measured at 10 m the wind in Adair County averages 2.85 m/s; at 50 m it is 4.69 m/s. That gives a shear exponent of 0.309, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 4,463 to 10,508 kWh a year, 135% 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 | 3.53 m/s | 4,463 kWh | over 100 years |
| 30 m | 4.01 m/s | 6,603 kWh | over 100 years |
| 40 m | 4.38 m/s | 8,618 kWh | 82 years |
| 50 m | 4.69 m/s | 10,508 kWh | 67 years |
Counties around Adair County
5 of the 6 closest counties are windier at turbine height; the windiest, Taylor County, averages 4.45 m/s.
- Russell County, KY: 4 m/s, 6,577 kWh, payback over 100 years (15 mi)
- Taylor County, KY: 4.45 m/s, 9,041 kWh, payback 78 years (18 mi)
- Green County, KY: 4.45 m/s, 9,041 kWh, payback 78 years (18 mi)
- Metcalfe County, KY: 4.28 m/s, 8,064 kWh, payback 87 years (21 mi)
- Cumberland County, KY: 4.28 m/s, 8,064 kWh, payback 87 years (23 mi)
- Casey County, KY: 4.07 m/s, 6,934 kWh, payback over 100 years (25 mi)
Sun versus wind in Adair County
Adair County gets 4.15 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,212 kWh a year; one kW of the turbine above makes 658. Kilowatt for kilowatt, panels make 1.8 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.