Wind Turbine Payback in Allen County, KY
Wind turbine payback in Allen 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 Allen County, KY averages 4.47 m/s (10 mph). A 10 kW turbine there would make about 9,160 kWh a year, worth $1,301 at KY's 14.2¢/kWh. Against an installed cost of about $100,000, that is a payback of 77 years, and the turbine is built to last about 20.
What to do in Allen County
A home turbine is not worth buying for savings in Allen County unless your spot is far windier than the county average, 8.2 m/s at the hub against 4.47 m/s here. Per kW, solar panels would make about 1,235 kWh a year here against the turbine's 916, so get a solar quote first.
What would have to change
- Power would have to cost 55¢/kWh, 3.8 times what KY pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 4.47. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of KY
Allen County is the 1,760th 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 Allen County
March is the strongest month here, at 5.34 m/s and about 1,264 kWh. August is the weakest, 3.30 m/s and 304 kWh, so the best month makes 4.2 times the worst. November to March brings in 57% of the year's output in Allen County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.20 m/s | 1,182 kWh | $168 |
| February | 5.28 m/s | 1,109 kWh | $157 |
| March | 5.34 m/s | 1,264 kWh | $179 |
| April | 5.35 m/s | 1,229 kWh | $175 |
| May | 4.36 m/s | 725 kWh | $103 |
| June | 3.70 m/s | 425 kWh | $60 |
| July | 3.32 m/s | 309 kWh | $44 |
| August | 3.30 m/s | 304 kWh | $43 |
| September | 3.73 m/s | 435 kWh | $62 |
| October | 4.39 m/s | 737 kWh | $105 |
| November | 4.80 m/s | 921 kWh | $131 |
| December | 4.97 m/s | 1,048 kWh | $149 |
What a taller tower would buy
Measured at 10 m the wind in Allen County averages 3.21 m/s; at 50 m it is 5.22 m/s. That gives a shear exponent of 0.302, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 6,369 to 14,046 kWh a year, 121% 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 | 3.96 m/s | 6,369 kWh | over 100 years |
| 30 m | 4.47 m/s | 9,182 kWh | 77 years |
| 40 m | 4.88 m/s | 11,733 kWh | 60 years |
| 50 m | 5.22 m/s | 14,046 kWh | 50 years |
Counties around Allen County
1 of the 6 closest counties is windier at turbine height; the windiest, Simpson County, averages 4.5 m/s.
- Macon County, TN: 4.45 m/s, 9,041 kWh, payback 80 years (18 mi)
- Barren County, KY: 4.28 m/s, 8,064 kWh, payback 87 years (21 mi)
- Warren County, KY: 4.47 m/s, 9,160 kWh, payback 77 years (21 mi)
- Simpson County, KY: 4.5 m/s, 9,339 kWh, payback 75 years (22 mi)
- Sumner County, TN: 4.45 m/s, 9,041 kWh, payback 80 years (24 mi)
- Trousdale County, TN: 4.45 m/s, 9,041 kWh, payback 80 years (25 mi)
Sun versus wind in Allen County
Allen County gets 4.23 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,235 kWh a year; one kW of the turbine above makes 916. Kilowatt for kilowatt, panels make 1.3 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.