Wind Turbine Payback in Union County, KY
Wind turbine payback in Union 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 Union County, KY averages 5.26 m/s (11.8 mph). A 10 kW turbine there would make about 14,327 kWh a year, worth $2,034 at KY's 14.2¢/kWh. Against an installed cost of about $100,000, that is a payback of 49 years, and the turbine is built to last about 20.
What to do in Union County
A home turbine is not worth buying for savings in Union County unless your spot is far windier than the county average, 8.2 m/s at the hub against 5.26 m/s here. Per kW, solar panels would make about 1,223 kWh a year here against the turbine's 1,433, so get a solar quote first.
What would have to change
- Power would have to cost 35¢/kWh, 2.5 times what KY pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 5.26. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of KY
Union County is the 1,339th 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 Union County
April is the strongest month here, at 6.28 m/s and about 1,788 kWh. July is the weakest, 3.91 m/s and 521 kWh, so the best month makes 3.4 times the worst. November to March brings in 54% of the year's output in Union County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.01 m/s | 1,682 kWh | $239 |
| February | 6.01 m/s | 1,519 kWh | $216 |
| March | 6.15 m/s | 1,770 kWh | $251 |
| April | 6.28 m/s | 1,788 kWh | $254 |
| May | 5.24 m/s | 1,206 kWh | $171 |
| June | 4.42 m/s | 728 kWh | $103 |
| July | 3.91 m/s | 521 kWh | $74 |
| August | 3.94 m/s | 535 kWh | $76 |
| September | 4.40 m/s | 719 kWh | $102 |
| October | 5.31 m/s | 1,248 kWh | $177 |
| November | 5.77 m/s | 1,478 kWh | $210 |
| December | 5.76 m/s | 1,522 kWh | $216 |
What a taller tower would buy
Measured at 10 m the wind in Union County averages 3.96 m/s; at 50 m it is 6 m/s. That gives a shear exponent of 0.258, typical of ordinary open country. Going from 20 m to 50 m takes output from 10,805 to 19,704 kWh a year, 82% 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 | 4.74 m/s | 10,805 kWh | 65 years |
| 30 m | 5.26 m/s | 14,321 kWh | 49 years |
| 40 m | 5.66 m/s | 17,231 kWh | 41 years |
| 50 m | 6 m/s | 19,704 kWh | 36 years |
Counties around Union County
3 of the 6 closest counties are windier at turbine height; the windiest, Gallatin County, averages 5.53 m/s.
- Gallatin County, IL: 5.53 m/s, 16,254 kWh, payback 32 years (17 mi)
- Webster County, KY: 4.88 m/s, 11,734 kWh, payback 60 years (17 mi)
- Hardin County, IL: 5.26 m/s, 14,327 kWh, payback 36 years (20 mi)
- Crittenden County, KY: 5.26 m/s, 14,327 kWh, payback 49 years (22 mi)
- Henderson County, KY: 5.42 m/s, 15,462 kWh, payback 46 years (23 mi)
- Posey County, IN: 5.53 m/s, 16,254 kWh, payback 36 years (26 mi)
Sun versus wind in Union County
Union County gets 4.19 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,223 kWh a year; one kW of the turbine above makes 1,433. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.2 times. 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.