Wind Turbine Payback in Carroll County, KY
Wind turbine payback in Carroll 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 Carroll County, KY averages 3.76 m/s (8.4 mph). A 10 kW turbine there would make about 5,432 kWh a year, worth $771 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 Carroll County
A home turbine is not worth buying for savings in Carroll County unless your spot is far windier than the county average, 8.2 m/s at the hub against 3.76 m/s here. Per kW, solar panels would make about 1,183 kWh a year here against the turbine's 543, so get a solar quote first.
What would have to change
- Power would have to cost 92¢/kWh, 6.5 times what KY pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 3.76. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of KY
Carroll County is the 2,236th 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 Carroll County
January is the strongest month here, at 4.42 m/s and about 751 kWh. July is the weakest, 2.82 m/s and 178 kWh, so the best month makes 4.2 times the worst. November to March brings in 58% of the year's output in Carroll County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.42 m/s | 751 kWh | $107 |
| February | 4.45 m/s | 693 kWh | $98 |
| March | 4.38 m/s | 735 kWh | $104 |
| April | 4.39 m/s | 715 kWh | $102 |
| May | 3.62 m/s | 408 kWh | $58 |
| June | 3.17 m/s | 257 kWh | $36 |
| July | 2.82 m/s | 178 kWh | $25 |
| August | 2.83 m/s | 181 kWh | $26 |
| September | 3.16 m/s | 255 kWh | $36 |
| October | 3.71 m/s | 444 kWh | $63 |
| November | 4.00 m/s | 541 kWh | $77 |
| December | 4.11 m/s | 609 kWh | $86 |
What a taller tower would buy
Measured at 10 m the wind in Carroll County averages 2.43 m/s; at 50 m it is 4.6 m/s. That gives a shear exponent of 0.397, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 3,222 to 9,947 kWh a year, 209% 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 | 3.2 m/s | 3,222 kWh | over 100 years |
| 30 m | 3.76 m/s | 5,412 kWh | over 100 years |
| 40 m | 4.21 m/s | 7,678 kWh | 92 years |
| 50 m | 4.6 m/s | 9,947 kWh | 71 years |
Counties around Carroll County
4 of the 6 closest counties are windier at turbine height; the windiest, Jefferson County, averages 4.82 m/s.
- Switzerland County, IN: 3.91 m/s, 6,134 kWh, payback 96 years (12 mi)
- Trimble County, KY: 4.61 m/s, 10,008 kWh, payback 70 years (13 mi)
- Henry County, KY: 3.76 m/s, 5,432 kWh, payback over 100 years (15 mi)
- Gallatin County, KY: 3.91 m/s, 6,134 kWh, payback over 100 years (15 mi)
- Jefferson County, IN: 4.82 m/s, 11,341 kWh, payback 52 years (19 mi)
- Owen County, KY: 3.76 m/s, 5,432 kWh, payback over 100 years (19 mi)
Sun versus wind in Carroll County
Carroll County gets 4.05 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,183 kWh a year; one kW of the turbine above makes 543. Kilowatt for kilowatt, panels make 2.2 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.