Wind Turbine Payback in Madison County, KY
Wind turbine payback in Madison 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 Madison County, KY averages 4.1 m/s (9.2 mph). A 10 kW turbine there would make about 7,090 kWh a year, worth $1,007 at KY's 14.2¢/kWh. Against an installed cost of about $100,000, that is a payback of 99 years, and the turbine is built to last about 20.
What to do in Madison County
A home turbine is not worth buying for savings in Madison County unless your spot is far windier than the county average, 8.2 m/s at the hub against 4.1 m/s here. Per kW, solar panels would make about 1,206 kWh a year here against the turbine's 709, so get a solar quote first.
What would have to change
- Power would have to cost 71¢/kWh, 5.0 times what KY pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 4.1. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of KY
Madison County is the 1,994th 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 Madison County
January is the strongest month here, at 4.83 m/s and about 970 kWh. August is the weakest, 3.06 m/s and 237 kWh, so the best month makes 4.1 times the worst. November to March brings in 58% of the year's output in Madison County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.83 m/s | 970 kWh | $138 |
| February | 4.87 m/s | 897 kWh | $127 |
| March | 4.81 m/s | 956 kWh | $136 |
| April | 4.77 m/s | 907 kWh | $129 |
| May | 3.96 m/s | 540 kWh | $77 |
| June | 3.46 m/s | 343 kWh | $49 |
| July | 3.17 m/s | 267 kWh | $38 |
| August | 3.06 m/s | 237 kWh | $34 |
| September | 3.42 m/s | 330 kWh | $47 |
| October | 4.02 m/s | 569 kWh | $81 |
| November | 4.34 m/s | 693 kWh | $98 |
| December | 4.54 m/s | 812 kWh | $115 |
What a taller tower would buy
Measured at 10 m the wind in Madison County averages 2.83 m/s; at 50 m it is 4.87 m/s. That gives a shear exponent of 0.337, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 4,637 to 11,668 kWh a year, 152% 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 | 3.58 m/s | 4,637 kWh | over 100 years |
| 30 m | 4.1 m/s | 7,089 kWh | 99 years |
| 40 m | 4.52 m/s | 9,442 kWh | 75 years |
| 50 m | 4.87 m/s | 11,668 kWh | 60 years |
Counties around Madison County
3 of the 6 closest counties are windier at turbine height; the windiest, Clark County, averages 4.7 m/s.
- Garrard County, KY: 4.1 m/s, 7,090 kWh, payback 99 years (16 mi)
- Estill County, KY: 3.4 m/s, 3,942 kWh, payback over 100 years (17 mi)
- Clark County, KY: 4.7 m/s, 10,571 kWh, payback 67 years (18 mi)
- Jessamine County, KY: 4.7 m/s, 10,571 kWh, payback 67 years (20 mi)
- Fayette County, KY: 4.7 m/s, 10,571 kWh, payback 67 years (24 mi)
- Powell County, KY: 3.9 m/s, 6,085 kWh, payback over 100 years (25 mi)
Sun versus wind in Madison County
Madison County gets 4.13 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,206 kWh a year; one kW of the turbine above makes 709. Kilowatt for kilowatt, panels make 1.7 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.